Gating Manual
NORTH AMERICAN DIE CASTING ASSOCIATION
Publication # 512
Although great care has been taken to provide accurate and current information, information, neither the author(s) nor the publisher, nor anyone else associated with this publication, shall be liable for any loss, damage or liability directly or indirectly caused or alleged to be caused by this book. The aria cnaind hrin i n inndd prvid pcic advic r rcndain fr an pcic iain. An pinin xprd b h ahr() ar n ncari h f NADCA. Trademark notice: Product or corporate names may be trademarks or registered trademarks and ar d n fr idnicain and xpanain ih inn infrin nr ndr h prdc or corporation. © 2006 b Nrh Arican Di Cain Aciain, Aciain, Arinn Hih, Iini. A Rih Rrvd. Nihr hi b nr an par a b rprdcd r ranid in an fr r b an an, crnic r chanica, incdin phcpin, icrin, and rcrdin, r b an information storage and retrieval system, without permission in writing from the publisher.
GATING MANUAL
TABLE OF CONTENTS STEP 1 - DeteRmINe tHe CAstINg QuAlIty ReQuIRemeNts STEP 2 - DeteRmINe tHe Flow F low PAtteRN PAtteRN AND loCA loCAtIoN tIoN oF tHe INgA INgAtes tes AND outgA out gAtes tes
9 15
STEP 3 - DeteRmINe tHe segmeNt Volumes, CAVIty FIll tIme, AND CAVIty metAl Flow RAte 27 STEP 4 - mAtCH tHe PRoCess to tHe Flow RAte
35
STEP 5 - DeteRmINe tHe INgAte PARAmeteRs AND CHeCk FoR AtomIzeD Flow
37
STEP 6 - Do A PQ 2 ANAl ANAlysIs ysIs IF DesIReD
45
tH e FAN AND tANgeNtIAl tANgeNtIAl RuNNeRs RuN NeRs STEP 7 - DesIgN tHe
53
STEP 8 - DesIgN tHe oVeRFlows AND VeNts
75
STEP 9 - sImulAtIoN
81
GATING MANUAL
INTRODUCTION th di cain di i h har f h di cain prc. gd ain din i nia fr ain d par and ad h a ccf di cain. Cnvr, pr ain din makes poor parts and contributes to the struggles in lowering scrap and meeting operational operational objectives. This manual describes what the engineer needs to know to develop a successful die cain a din. th na ain din incd a cp f infrain and drain that the tool designer or toolmaker toolmaker will use to construct the gating system in the die. There is a lot of thought and calculations that go into developing gating designs. The best designs come from di cain xprinc, NADCA ain ain fra, and h idin prnd in hi x. gain din a ninrin r and i. Hvr, Hvr, h i invd id hihr qai cain and hp flr prdcivi. thi x i inndd fr h prc ninr, h in ninr, h di dinr, h toolmaker, the production supervisor or whoever has input into the gate design. The more people in the organization who are on the same page for gating theory and practice, the better for a pan’ pan’ cc. mch f h infrain i cncrn cd chabr ain achin, inc hi cpri f h rd’ di cain acivi. Hvr, h ain chniq prnd in hi x app h inc and ani a a . gain din i inraciv ih h prc. Chic ad in cin h prc facr i inflnc h a din. trad ar ad in h dvpin h ain h pan’ processes. The analysis is done many times until the best and hopefully most robust design is achieved that works with the process factors chosen. Fr xap, cin a a ara cann b dn prpr ih nin h xpcd h pd and pnr i; and hi cann b drind ih nin h dird i; and h i cann b drind ih nin h qai rqirn fr h par and h achin capabiii. Chanin n f h facr can ac h hr. th ain din r incd cin f h fl parn, h r and cain f h ina, rnnr, vrfl, and vn. I a incd h dvpn f h prc parar. If a i dn rih, hn r h cc i xpcd ih h prc parar very close to those calculated in the gating analysis. ohr facr n cnidrd in h a din cacain ar a ipran fr cain qai. qai. Fr xap, if h di rn h r cd d pra cndiin, cc i, ar fl, fl, h i prar, c., r h prc rn ih an incnin cc i, hn h b a din in h rd a n r. evn hh h facr ac h cain qai, qai, sometimes the gate design is considered at fault when defects occur. occur. Thus, a gate design that has h rih hap, ha i in h rih cain, and ha a d fl parn, a n nra h xpcd qai if n r r f h hr prc facr ar f cnr. Chanin h a design is not always the answer to the problem, though some shops change the gate design as a a v a a ind f prb. Fr h dinr, dinr, hi an ha h h prc nd b xaind bfr dvpin a a din, and ha h b r ar baind when the designer knows and makes allowances for the operational practices of the shop where the die is to be run.
GATING MANUAL
The calculations presented have been used for some time. The formulas and guidelines are based on empirical data and the results are successful especially when compared to the “let’s try hi” chniq. I i pin hr c f h hd prnd, pcia hn h a r i and r han pa pracic. Hvr, h chniq hav bn prvn b civ and ar aa br if dn carf and cp. evr r hd b ad bain iin infrain ch a a d dniin f h cain qai rqirn r achin prfranc information and to do the gate design as a thorough engineering project. This approach may cost more initially, but will always prove to be substantially cheaper in the long run when all costs are cnidrd. sa f h pan r ria and rrr rai ar xpniv and a nvr achiv crap and praina fcinc a. sa iprvn in qai ar criica in da’ ar. odr hd a achiv a 5 10% crap ra, and a hav bn r han adqa fr rda’ ar. Hvr, da’ market is a lot tougher with slimmer margins and has little room for operational error in order to a a pr. od hd n’ c i an r and br ain din ar ndd rviv and succeed in today’s market. s biv ha cann rach h vr v f crap ih a f xpniv ria and rrr di dvpn c. Hvr, h cpani ha rac h ra c f di development that comes from welding and re-cutting a gate or runner, will realize that the up front engineering costs of doing a proper gate design are a real bargain. th r a din hd a b h prann r a din. Ahh hi a in’ achivd 100%, i i b h ca in h ra ajri f din if h NADCA fra and idin ar fd ivn ha d qipn, d prc cnr, and rb di ar a in place.
GATING MANUAL
The Steps to a Good Gate Design The following steps are used to develop a proper gate design:
1.
Drin h cain qai rqirn. gd ain din ar ih nd f h cr rqirn.
2.
Drin h inndd fl parn and h ina and h a cain. Viai h fl f h a hrh h di. sn h cain and drin h dird fl angles.
3.
Drin n v, h cavi i, and a fl ra fr ach n and for the entire casting.
4.
Dn h prc cnrain f h achin() inndd rn h par – fa h vci, pnr i, and cain prr. wha ar h pnr ip, prr, fa h vci arnaiv? Can h inndd achin divr h dird fl ra and prr?
5.
Fr ach cain n drin h fl ra, h ina vci, h apparn ina ara, h fl an, h aca ina ara, and h ina nh and hicn. Chc fr aid fl. Chc h r fr h nir cain aain h prc ii. Rd h anai ni aid.
6.
If dird d a PQ 2 gating analysis.
7.
Din h rnnr ppr h ina() rin bac h bici f pr.
8.
Din h vn and vrfl .
9.
If dird rn h din vr h iain far n n h din. th iar a h fl parn, h and cd ara, and pr ara ha r n visualized in Step 2.
GATING MANUAL
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1
STEP 1 – DETERMINE THE CASTING QUALITY REQUIREMENTS
QUALITY SPECIFICATIONS th dinr nd ndrand h cr’ cain qai pcicain and h h par fncin in h appicain. H d d h nih hav b – pain qai, n cd fl, r cd fl? H ipran i pri – a , pri in crain ara, r n pri rqirn? wha a h par r in h appicain? wha ar h criica characteristics on the print? t dvp a d a din, i i ipran ha h cain pcicain b dnd a cp a pib. In an ca h cr i n an xpr in di cain and h di car fr idanc. Ida, h di car and cr a a jin r pii h din and qai pcicain fr h cain. A Din FmeA i f in hi ndavr and hd b dn fr vr cain. Afr din a Din FmeA chan ar frqn ad a h cain din br and a pari ar n h a pa fr ha i rqird a h cain r in h appicain. od hd ch a “dpin h din vr h ran” forces the die caster to make assumptions that can lead to sub-optimized gating designs resulting in sub-optimized production with high scrap rates, misunderstandings, etc. si qai pcicain ha ar criica h di car ininican h cr. Fr xap, an prad in h rqirn fr rfac nih r pri a chan h achin ndd, and i i ca a chan in h ain din. If hi i dicvrd afr h di i bi and an irrvcab dciin hav bn ad, an chan i b xpniv fr vrn cncrnd. I i incbn fr h di car a h rih qin. thr ar ajr dfc prb ara in di cain -rfac nih and pri. s cnidrain fr h dinr ab qai rqirn in h ara ar id b:
SURFACE FINISH srfac qai i aa a cncrn and nd b cnidrd in a a din. Hvr, h rfac nih rqirn can var id. thr i a bi dirnc in ain dvpn between a chrome plated decorative zinc casting and a functional aluminum part. sinc rfac nih i bjciv, h NADCA Prdc sandard chci C-8-2-06 i vaab in hpin dvp a r pcic andard fr an ivn par. A cp f h chci i hn n h nx pa.
GATING MANUAL
9
STEP 1 – DETERMINE THE CASTING QUALITY REQUIREMENTS
CASTING SURFACE FINISHING SPECIFICATIONS t b d in cnain ih r car (u in cbinain ih Chci C- 8 -1)*
Checklist for Finished Die, SSM and Squeeze Casting Part Purchasing thi Finihin Chci prvid a cnvnin hd fr arin ha ipran facr invvd in h rfac nihin f ca par ar vaad and car cnicad bn the purchaser and the caster. This checklist is for use in consultation with your die caster prior to estimat- ing production c. u in cbinain ih h Finihin Chci C-8-2. A rvi Chci t-2-1A and t-2-1B, fr Di Cain Di spcicain, in scin 2. I hd b d a a ppn h nia dinina and a pcicain daid n par prin bid fr qain, inc h id facr dirc ac h bai n hich h cain qain i ad. th chci a b rprdcd fr hi prp. yr car i carif an i rqirin xpanain. This checklist provides a numbering system in which the lowest numbered description for each rqirn can b a h prdcin c, a f:
GATING MANUAL
STEP 1 – DETERMINE THE CASTING QUALITY REQUIREMENTS
* The specification provisions and procedures listed in Section 7, “Quality Assurance,” should also be addressed. Publisher grants permission to reproduce this checklist as part of a casting Request for Quotation or Production Specification .
GATING MANUAL
STEP 1 – DETERMINE THE CASTING QUALITY REQUIREMENTS
thr i b fr ain din facr ha ac h rfac nih – fl parn, cavi i, ina vci, and vrfl i. th facr and hir c n rfac nih i b dicd ar in h ana. th inn hr i hp h dinr pan fr rfac qai rqirn and arn a ch a pib ab h nih rqird. thr i b jdna va b abihd ar fr i, hich i dicd in h nx cin, b h fin i iv idanc.
Surface Finish Quality requirements
Guidance for selections usd dur fi tm calculation
General considerations in fl pttr ds
Avra ( inr cd fl permissable)
midd hih nd va f time
s inr in and ir ar n problem
gd (n cd fl viib)
midd va f i
mini ir, ini fl lines
excn (painin r pain rad nih)
shr pib i
N ir, n fl in, vn in small areas
th dciin ad ar hn abihin h cavi i i drin h achin capabilities needed, but the choice at this point is about “how good is good”, or what are the rqird rfac qai v. th inn f rviin h rfac qai i a hi i i rv qin ha b rfrrd h par dinr. Chanin h nih qai rqirn ar a invv chanin achin r din a dirn di din, h i nd b rvd ar.
INTERNAL QUALITY OR POROSITY CONSIDERATIONS th pri cncrn nd b dnd h a din can b dvpd accrdin. th two types of porosity that will cause the most concern are shrink porosity and gas porosity. shrin pri ccr bca ca a hrin hn h fr h iqid a h id a. sinc h a fr h di r, h pac f vr a h nd f idicain will be inside the casting and is called shrink porosity. They will be located at the last point to solidify in the hottest and thickest areas in the casting. The only way to feed more material into h pac and rdc h i hrin fd r a drin idicain. thi i a dn ih hih prr appid a h nd f h h. If h ina i hin and fr prematurely, then the shrink porosity is left in the part. shrin pri can b xpd drin achinin. I can a ca in, a fair, and cracks. The gating system should allow delivery of metal under high pressure at the right location with high pressure to address the shrink porosity issues. ga pri c fr rappd air, a, r vaid brican. Hdrn a pri can be a problem in aluminum die casting, but the gas content from the other sources is often so large that hydrogen gas is a very small percentage of the total.
GATING MANUAL
STEP 1 – DETERMINE THE CASTING QUALITY REQUIREMENTS
ga pri i fn a cncrn fr achind ara, r i a h p a bir in hr ara. wih a pri h a din i incd dvpin a fl parn ha dn’ prdc ir r bac and dvpin h prpr vnin and r vac . s dniin f par qai rqirn nd b ndrd ar a h rqirn ac h ain din ra and dciin ain prc.
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STEP 2 – DETERMINE THE FLOW PATTERN AND LOCATION OF THE INGATES AND OUTGATES
GENERAL CONSIDERATIONS A ain din ar ih a rand pan fr h a fl hrh h di. whr i h ica and avaiab pac fr h a c in? whr i h ica and avaiab pac fr h air cap? wha bac h a fl i b ncnrd inid h cavi? wha parn i b aif h qai rqirn? Viaiin h fl parn i a criica p in h ain din prc. whn h fl parn i dnd, hn h ina and a can be located provide the desired pattern. In viaiin h a fl: 1.
u a ch f h parin in a pib divr a hr i i ndd and spread the heat out,
2.
Take the shortest distance across the cavity, and
3.
minii divrin and cnvrin fl pah.
Par f viaiin h a fl pah i a viaiin h cpnn ha i fd h a. Hr ar irain f h fl cin a crv idd fan and annia rnnr.
GATING MANUAL
STEP 2 – DETERMINE THE FLOW PATTERN AND LOCATION OF THE INGATES AND OUTGATES
th a fl an i hn in hi r.
A long rectangular part can be gated with a fan and two tangential runners.
Fiin a crnr can b dn ih a fan and pib annia rnnr. Rnd par prn difci in in h parn rih prvn bacin a h far nd f h cain. th ingates need to vary in depth.
GATING MANUAL
STEP 2 – DETERMINE THE FLOW PATTERN AND LOCATION OF THE INGATES AND OUTGATES
th vra a fl pan can b dran n h priinar di din prin.
of priar ipranc h nviind fl parn ar h qai i. F nd b dircd ara ha nd h b rfac nih r a cain hr hr ar pri rqirn. th, an ara ha ha pcia qai rqirn hd rciv dirc fl and should be close to the gate if possible. th a cain hd b ch ha hr i a ch nbrcd a fl dianc h ara f cncrn. th a a f nr hn h fl ipac dirc n a a. Adjin h parin in r vin h a h fl can avid dirc ipac i rh h r.
GATING MANUAL
STEP 2 – DETERMINE THE FLOW PATTERN AND LOCATION OF THE INGATES AND OUTGATES
In in h fl parn, h ninr hd rvi h cain f ara xpcd b a . th cain ar aa pc fr pib pri and pr rfac nih. In pacin h par in h di, h a pin hd b cad hr i i pib pac vn and vrfl. Drinin h cain f h a pin i an ipran par f h fl pattern decision, and it is one of the major uses of simulation software.
USING CAVITY SEGMENTS TO DEVELOP FLOW PATTERNS AND GATE LOCATIONS th dniin f h fl parn and h a cain incd dividin h cain p in n. whi h nd fl pan i viaid, fan and annia rnnr cpnn ha fd h ina ih fl an ar a viaid. snin h cain inr criica ara and difc ara ar addrd and ha n fl ar baancd ih h rnnr components in mind. Best results are usually obtained by keeping the number of segments to a ini – pica 2 4. each n hd hav an ina, and h din hd b ch ha h fl fr n a j ha n.
Smts sud b cs by t f uds: Qai i. If a cin f a cain ha a dirn qai rqirn han h r f h cain, hn cnidr ain i a n. Fr xap, if a cin ha a vr hih qai rfac nih rqirn a cpard h r f h cain, hn i hd b chn a a segment. Nara fl pah. l fr rib r hicr cin ha i prvid a nara pah fr a fl. A, fr bac ha i frc h a divr. evaa h cndiin in h nara a fl pah. If h cain ha an pn ara ha divid h fl, r a ach id f h dividd fl if hr ar dirn ri fr h fl pah. Fr xap, if h a hicn n n id a db h a hicn n h hr id, hn each side probably should be a separate segment. Cain hap. sn hd b d hr ara hav bania dirn a hicn. Dirn n ar a apprpria if h fl dianc i bania dirn fr n n anhr. Cnidr h pah f h a a i i rflcd fr a a dvp h fl dianc. An prin f h cain ih far ha ar cnidrd hard , pcia if h far ar cad a h nd f h cain ih h frh fl dianc, can b ad in a separate segment. In nra, n hd b dirn fr ach hr r fd b a paricar rnnr. Dirn a hicn, dirn fl nh, dirn qai rqirn, r dirn r, r dirn rnnr ar pica ran fr cin n. enia, n i divid h cain and ar rad in h ain anai a para cain. each n i hav an ina, and i b id in dirc prprin h v that it feeds relative to the other segments.
8
GATING MANUAL
STEP 2 – DETERMINE THE FLOW PATTERN AND LOCATION OF THE INGATES AND OUTGATES
th a ara hd b ch ha ach n i hav h a i and h cncp f ian i achivd. If h n r ninrd ih dirn i, hn n n’ fl i pi vr in anhr n cain ir and bac adin pr and porosity. A simple way to keep track of segment gate areas is to develop a table like the following:
Segment
Volume of Segment
Volume as a Percent
Gate Area for each Segment
#1
0.2
20%
0.07
#2
0.3
30%
0.105
#3
0.5
50%
0.175
Total
1.00
100%
0.35
The fraction of the total volume of each segment is multiplied times the total casting ingate ara h n ina ara. th principa i baanc n a fl ara segment volumes. This same principle is used when doing the gating for a multi-cavity die. th ran fr dividin h cain in n can b n in h fin xap:
on h f id i a cain ih qa a. th cain i dividd in n, ih h ar n n h f bin ic a ar a h n n h rih. wih qa fl, h rih n qicr, and afr i i nihd in, h a i fl a hn ih h red arrow along the back side of the casting into the other segment, which will tend to be an area f cd fl and pr prb. on h rih i h a cain, b h a ara hav bn adjd ach h n volumes.
GATING MANUAL
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STEP 2 – DETERMINE THE FLOW PATTERN AND LOCATION OF THE INGATES AND OUTGATES
sinc n A i ic a ar a n B, h a fr A i ad ic a ar a h a fr B, cnqn h n nih in a h a i, and cr fl bn segments is minimized. thi cncp f havin h a i fr a n r prprinin a fl ara segment casting volumes is fundamental to good gate design. The same concept applies when dinin a fr dirn cavii in h a di, hr h din a i hav ach cavi nih in a h a i. In hi ca, h a fr dirn cavii in h a di ar sized in proportion to the cavity volumes. exprinc i hp ica n h cain. Hvr, vn fr cpx hap, h number of segments is usually kept to 2, 3 or 4.
FLOW PATTERN GUIDELINES Sm r rus d uds fr stt t fl pttr ud b s fs: 1.
Dirib h fl. th fl parn hd aa b diribd and n fcd in small jets with a few small narrow gates. These small jet gates are good for some kinds of pri cnr, b n h a i fc fl in a a ara fr pri cnr, i i ch br a diribd fl parn. A diribd fl prad h ina, hich r in a idr and hinnr a. th heat is also distributed over a large area allowing for better temperature control and longer die life. Thin gates will not erode or “burn out” if the gate velocities ar ihin NADCA idin. th ini hicn in ain i ab pica ab .040, ahh i can b if h a i cand and rd c hr i i add. zinc a ar pica ab .015 .020, ahh h can b hinnr a ih inar inc. mani can b h a a inc, b hd ar a ab .02 .04. Fan and annia rnnr hd b d dirib h fl fr h ain rnnr. Chi rnnr prdc a id j ra ha ca ir, rappd a and pr . wid ina i a rap a, b h diribd fl parn i a bra p and dirib h rappd a and h a fr br .
GATING MANUAL
STEP 2 – DETERMINE THE FLOW PATTERN AND LOCATION OF THE INGATES AND OUTGATES
2.
Dirc h fl ard h criica qai ara. thi i r hhr h prb i pri r rfac nih.
Surfc fis. If n f h qai i i a d rfac nih, hn dirc fl fr h ina h ar rqirin d rfac. th a hd b cad a c h ara a pib, and h fl hd b a nbrcd a pib. If hr i a chic ab parin in cain, i i ipran fr h b nih if h fl is directed into the area of concern, as shown below.
Aid fl i b fr a d nih. If h a dn, h fl i drp f h anid fl ran, and h nih i bc han pia. th fl dianc fr d nih can b p 7”. Hvr, hi dianc dpnd pn h brcin encountered, the metal temperature, the die temperature, the gate velocity, and the cain a hicn. Incin a i n ainain d pd hrh r han ab 2 r 3 rflcin. ma vcii hihr han nra i prvid br nih, hvr, ih ain a hih a vci can ca prar a rin and dr. Hih a vcii ih inc and ani can ca drin. ga vcii hd b p a h hih nd f h ran fr h b nih b n xcd h hih ii f NADCA idin.
Prsty ssus. Fr hrin pri, h fl a nd b dircd rih a h prb ara. In hi ca, h a hd b hicr da ina frin ain r i for shrink feeding to occur. th a rnnr rai hd a b ar hr i r ca ha. Rnnr ih a 45° rap h a can b d ainain ha pin h ina fr frin n. whi hi apprach p h a ara h, i a nd rdc di if arnd the ingate. A gate thickness of about .080” (2 mm) should be considered a mimimum for porosity control, and a thicker gate should be considered if it can be trimmed. A gate thickness f.125 in (3.2 ) can a b rid, and vn hicr a ar pib ih properly built trim dies or by sawing.
GATING MANUAL
STEP 2 – DETERMINE THE FLOW PATTERN AND LOCATION OF THE INGATES AND OUTGATES
A gate intended to feed shrink porosity should be located as close to the problem area as possible. A small but thick gate can be fed by a larger than normal runner in a location away from the main gate. The sole purpose of this kind of gate is to feed an area of pib hrin pri, and i hd n b cnd n iprv rfac nih. Aa r and fl h a acr h hr pah fr ina a. th a heat and drops in temperature as it traverses the cavity. Taking the shortest path minimizes hra dirnc bn h nar and far id f h fl, and a a fr h b cnr f h parn ihin h cavi. th fl dircin hd b h hr dircin acr h cain n hr ar hr fl rricin r ran fr n din . thi an ha h r hh i rin h cain h ain d b n h n id. th xcpin i b if hr ar nara ipdin fl in h hr dircin. Fr h hap b, hr h inrna qar rprn c in h cain, h a fl d need to come from the end, the long way, instead of the short way across the casting, which would normally be preferable.
3.
u h nara cain hap dirc h fl. thi i an xcpin h r ab flin h hr a. If, fr xap, h cain abv had n an h p ha xndd h n a, hn h nara fl pah i ih h n and h fl hd b the long way instead of the short way. B ar fr nara fl pah, and r h. wach fr hic cin ha i id h a, fr xap, and r din a fl pah ha i ii hi nara fl pah.
4.
I i ipran p cain a hicn nifr, pcia fr ar fla rfac, hn a d rfac nih i rqird. si par dinr i pcif a ar hin cin, b p a rahr ar ranc n i. Fr xap, h a cin f a ar fla pic a b .080 “ +/- .010. I i a air a h cain a .088” hicn han a .072” hicn. If hr ar rib r b n a a cin, hn h NADCA idin fr a hicn and radii ar ipran fr a fl prp. wrin ih h ar a advana f prin ranc can hp ih in h di and rbn f h cain prc.
GATING MANUAL
STEP 2 – DETERMINE THE FLOW PATTERN AND LOCATION OF THE INGATES AND OUTGATES
5.
F h NADCA Prdc spcicain sandard fr Di Cain fr draf and radi. th andard a h cain ra fr h di iniiin dirin. Hvr, i adqa radii a h dirnc bn hhr a cain ha a fl parn ha r r n. th dirnc bn havin a radi and a harp crnr cd b h dirnc bn an accpab cain and crap. Havin radii ha cnfr NADCA din rcndain a hp ih di if. thrfr, h ini radi pcid in h NADCA pcicain hd b fd fr d fl parn dvpn. larr radii ar pcia vaab a h pin hr a i xpcd fl in b r n. Hvr, a rd f cain – if radii ar large, cracks can occur due to shrink porosity at the base of the rib or vertical wall.
6.
th hih vcii in di cain an h a fl characriic ar dinad b n. thi ha a nbr f ipicain. Fr xap, hn cnidrin h fl in a n r b n h p f a fla cin, h a i nra h pa h b, h nd f h cain, and hn bac and ar in h b a a hn b left. th n fl ar drin cain , b a n ra ni h h cain i prriin ard h nd f . thi a i difc h far. si i i ncar chan h r. Fr xap, di car add a dflcin b h cain h a dflc a hn b. Addin radii n h b f h n r b hp, b a n v h nir prb a hn b rih. whn hi i a prb, addin vac can b an civ in bca h rappd a in h n r b ri h a fl fr cin in.
7.
tr avid ain dirc n a vrica a r n a cr. th fl i vna ha chc r rd h di crain an ndrc and ca jcin prb. Hvr, if fl i rqird a hi cain, hn h r f vi i a n h far a h priri i h fl parn rih. th rflcin fr a a i nd ida and arnd h cain n h a ipin a c a 90° an. th, n ha prin f h fl ha i prpndicar h a i nd p h a. If h bjciv i h a p h a, hn h a b carf dind f h a fl ipin n h a a a 90° an. Anhr apprach i rn h a in h rnnr and ina fl a ih h a. Hvr, hi ra rqir fac iin a a cndar prain.
GATING MANUAL
STEP 2 – DETERMINE THE FLOW PATTERN AND LOCATION OF THE INGATES AND OUTGATES
8.
Avid ixin h a fl bn n. th fl an fr adjacn n hd b cincidn hr h . Divrin a fl fr adjacn n cra a ara rin in pr and pri. Cnvrin a fl fr adjacent segments cause hot areas resulting in thermal control problems.
9.
If pib, h fl hd n ipac n a a rv. ga rv nra hav a tight tolerance, and can be easily eroded.
10.
Cain ara bhind a cr r an pnin in h cain hr h a fl i b pi can b a prb. th ara ar candida fr pr and pri. If hi i a cncrn, hn h fl nd c fr dircin, a nd in h fin ch. thi apprach cd b d fr a pad inc cain ha nd a prfc nih, r fr an aluminum casting with a large hole that gets machined where there can be no porosity xpd b achinin.
GATING MANUAL
STEP 2 – DETERMINE THE FLOW PATTERN AND LOCATION OF THE INGATES AND OUTGATES
INGATE LOCATIONS onc h dird fl parn i abihd, hn ina cain can b pacd ih aciad a fl an. N ha fl an cann b rar han 45 dr a i b dicd later.
excp hr an r i ad hrin a ca ara fr pri, ina hicn hd b cpaib ih id a and diribd fl. ga hicn hd n xcd 75% f h par hicn in rdr ri ih dirin r bra. An ina hicn f 50% f h par hicn i br fr rdcin ri dirin and bra. If iain i d ar, hn there may be some changes in the gate location as a result of information learned in simulation.
OUTGATE, OVERFLOW, AND VENT LOCATIONS th ida pac fr a, vrfl, and vn i hr h a f h a i nara h di. thi i a hardr viai a h a can dflcd inid drin cavi . on h hr hand, vn hav a drain c n h a fl parn. Prhap hr ar iiar cain hr h a fl parn can b rad n cd ar p h and iv inih a hr h a, vrfl, and vn hd b fr h ain bin dind. Ara n h far nd f h cain ih anicipad pr and pri prb i bn ih adjacent outgates and vents.
GATING MANUAL
GATING MANUAL
3
STEP 3 – DETERMINE THE SEGMENT VOLUMES, CAVITY FILL TIME, AND CAVITY METAL FLOW RATE
SEGMENT VOLUMES Fr xiin cain, n v can b drind b cin h cain p ih a band saw, weighing each segment, and calculating the segment volume. The volume of a segment may be calculated with the following formula.
Volume (in3 ) = Weight (lb)/Density (lb/in3) whr, dnii ar:
Ain
= .096 b/in3
zinc
= .256 b/in3
mani
= .064 b/in3
lad
= .400 b/in3
Fr n cain h ai a drin n v i 3D CAD far nra n v. thi hd i fa and accra. whn an ain din cnari ar d and h cain i cciv rnd fr ach cnari, CAD a h prc fa and fcin. wih 3D CAD and a cprhniv pradh ha caca ina, rnnr, a, and vn, an ain inrain can b dn qic and fcin. B din an scenarios a better job of approaching the optimum gating design is done. A more time consuming method would be to determine the casting volumes with a spreadsheet and a cacar. thi hd i r and n a accra a 3D CAD and ain din qai i r. Pannd vrfl aciad ih ach n hd b incdd in n v. Incdin vrfl v ih n v i cad “a hrh h a” and id a r cnrvaiv din. each n v ih h pannd vrfl i pacd in h spreadsheet and then summed to get the total casting volume.
CAVITY FILL TIME Cavi i i h i fr hn h a bin fl in h di ni h cavi i f. ma fl in a di cain di i i a rac aain i. A h a nr h cavity and hits the die steel, it loses heat and drops in temperature. The metal must reach all xrii f h cavi bfr h a prar dcra h pin hr h a n nr fl and h ih cnvrin ra. If h rac i , hn pr and pri appar in h cain. whn drinin h cavi i fr a n cain hhr b fra, ab, r hirica daa, i i br nra rr n id f a fa i. th xcpin ih b h ca f pri i and fdin h far id f bi cr n hic cain hr fa times can actually make the castings worse. GATING MANUAL
STEP 3 – DETERMINE THE SEGMENT VOLUMES, CAVITY FILL TIME, AND CAVITY METAL FLOW RATE
th i cacad b h hd prnd hr ar cnidrd b axi i, and n ida i. th ran fr hi i bca f varin fl dianc and a dflcin ihin pcic di cain cavii. gnra qain and ab cann addr pcic fl dianc and brcin i. s h i cacain b fra hd b h ppr limit for any gating design. An ipran din cnidrain i ha hrr i bn rfac nih prvidd h a ara ar prprina n v. A cain rqirin a d nih nd a fa i and bc h dnin variab fr h r f h prc cin. Fa i can b cnraind b h vn. thr i a ii a h fa air can fl hrh vn. si fa i baind b drn achin a rqir r vnin ara han can b inad in a ivn di. In h ca, chi bc r a vac nd be considered. This is discussed in the section on venting. whi i i h ajr facr acin h rfac nih, h facr acin pri a n b rn acd b i. In h ca hr hrin pri i h dinan qai i, hn h i nd n b fa nh a d ih an avra nih. In fac, a r cavi i a hp pri b ain r air cap hrh h vn and b in ih a hihr pr cn id. th NADCA fra cnain facr h ain dinr a. wa hicn, di temperature, metal temperature, and percent solids come from the designer’s judgment of what i aca happn hn h cain i in prdcin. th, h cacad cavi va bc a fncin f h dinr’ xprinc and prcpin f aca flr pracic. A d database from process engineering on the actual process conditions of the shop is valuable when d in cnjncin ih NADCA’ fra. Dviain fr h fra and rcndain hd c fr hirica daa hich d b h b fr nin ha r fr a paricar ca f cain. th b i va a c fr h prc ninr h ha rn iiar par, and ha a daa ba cnainin i nbr. whn d i daa i avaiab, h va hd prcd h NADCA fra values. Fdbac i ipran fr an ain dinr. th aca cain r fr a din raiv cavi i hd b criiqd. wha rd? wha did n r ? Iprvin ain i i a jrn. ovr i ain dinr br a drinin cavi i va fr any particular operation. s cain ar ran f i variain, hi ar n. Hvr, ain dinr hd iv a cain ri hh a prpd cavi i pcia if h cain i plated of leak tested. J. A. waac (Pracica Appicain and h r f a fl and ain rarch – 1965) dvpd h baic NADCA i fra. e. A. Hran pbihd h crrn vrin in hi b, gain Di Cain Di. thi baic i fra i:
8
GATING MANUAL
STEP 3 – DETERMINE THE SEGMENT VOLUMES, CAVITY FILL TIME, AND CAVITY METAL FLOW RATE
=k{
ti - tf + sz Tf - Td
}T
whr: k = epirica drivd cnan rad h di t = wa hicn f h cain
= maxi i
tf = mini fl prar f h a a ti = ma prar a h ina td = Di rfac prar j bfr h a arriv s
= Prcn id a h nd f
z = sid ni cnvrin facr, dr %
Fr brvain f h fra, cavi i i prprina : 1.
Cain hicn, t. th hicr h a, h nr h i can b. th hinnr h a, the shorter the time must be.
2.
ma prar, tj. th hr h a, h nr h i can b. th cdr h metal, the shorter the time must be.
3.
Di prar, td. th hr h di, h nr h i can b. th cdr h di, the shorter the time must be.
4.
Prcn id, s. th hihr pr cn id a h nd f h , h nr h i. th r h prcn id, h hrr h i.
tf, h ini fl prar f h a i a cnan. k i h cnan f prprinai and i rad h hra cndcivi f h p f di d. N ha h NADCA fra d n addr fl dianc r brcin ihin h cavi h fl. Va fr h variab in h i fra can b an fr h fin ab: scin h va d in h fra dpnd n h jdn f h ain dinr. th following are some guidelines: (“t”) Cain a hicn. th fin hd ar d in cacain hi va: Thinnest wall section found anywhere on the casting. This method is conservative, and will id hrr i han a b rqird. uin h hinn a cin in NADCA’ fra dcra cavi i and i incra achin pr rqirn. A vr fa i a rqir a fa h vci ha i bnd h achin’ ppr ii.
GATING MANUAL
9
STEP 3 – DETERMINE THE SEGMENT VOLUMES, CAVITY FILL TIME, AND CAVITY METAL FLOW RATE
Avra cain a hicn. If h cain a hicn i fair nifr, and hr ar n pcic rfac qai i, hn h avra a hicn can b d. Hvr, fr pica cain ih nqa a hicn, h i a b rin in pr in h hin ara r in ara a h far nd f h fl. Avra hinn a hicn. thi i h hd rcndd. m cain hav nqa a hicn. uin h hinn par a cin ha can b fnd n h cain d pac nraiic brdn n h di cain achin fr fl ra and d n b ncar a h cain. If h cain hicn i nvn, hn caca an average thickness of the thinner wall sections. (“tf”). mini fl prar f h a. thi va i fnd in h char. (“ti “) tprar f h a a h a. on cd chabr achin hr i a a temperature drop between the holding furnace and the ingate. The drop for aluminum can b a i a 25°F (14°C) r a ch a 70°F (39°C) dpndin n h an f a pored, the ladle traverse time, the type of ladle cup, the pour rate, the shot delay time, the sleeve and die temperatures, the slow shot velocity and length, and the length and geometry of the runners. The following temperature drop values are suggested for typical operations: Aluminum (cold chabr) = 50°F (28°C) Ain (cd chabr) = 50°F (28°C) zinc (h chabr) = 30°F (17°C) mani (cd chabr) = 80°F (44°C)
5.
(“Td “). The temperature of the die surface just before the metal arrives. This is an anhr dic ia. In addiin, di prar vari acr h cavi. A an n ara h di prar bfr c i a fn n f cc ,di pra,can fl rate,etc.The process engineer’s data again would be helpful for similar parts or for general plant conditions in coming up with this number. lacking data it is suggested that the dinr 500oF (260oC) fr ain and ani and 400oF (204oC) fr inc.
6.
(“s”) th prcn id a h nd f . thi va rprn h idid prin f a a h nd f h fl pah a h i hn h cavi i f. th hihr hi facr, h r h rfac nih. Hvr,a hihr va f “s” hp hrin pri a hr i a hrin in chanin a fr iqid id. A hihr “s” va id a nr cavi i ih h hr facr hd cnan. If “s” i a 50%, hn hrica 50% f h a a h nd f i b id, andi hav cpd i dni chan yielding less shrink porosity.
GATING MANUAL
STEP 3 – DETERMINE THE SEGMENT VOLUMES, CAVITY FILL TIME, AND CAVITY METAL FLOW RATE
Alloy
Empirical Constant, K H-13/H-21 sec/mm sec/in
P-20 sec/mm
sec/in
Tungsten sec/mm sec/in
m
0.0252
0.640
0.0124
0.311
AI 360,380,384
0.0346
0.866
0.0124
0.311
Al390
0.0346
0.866
0.0124
0.311
zn 12,27
0.0312
0.799
0.0346
0.866
0.0124
0.311
zn 3,5,7
0.0312
0.799
0.0346
0.866
0.0124
0.311
F
0.0346
0.866
0.0124
0.311
C 60/40
0.0346
0.866
0.0124
0.311
C 85-5-5-5
0.0346
0.866
0.0124
0.311
0.0173
0.433
0.0156
Pb
Alloy
0.39
Metal Injection Temp M. F Tmp. D Cvty Tmp. Ti Tf Td o
o
c
o
F
o
c
o
F
Solids Factor Z
o
c
o
F
C/%
o
F/%
m
650
1200
510
1050
340
650
3.7
6.6
AI 360, 380, 384
650
1200
570
1060
340
650
4.8
8.6
Al390
720
1325
595
1100
355
675
5.9
10.6
zn 12,27
565
1050
445
835
260
500
3.2
5.7
zn 3,5,7
405
760
382
720
230
450
2.5
4.5
F
1540
2800
1370
2500
980
1800
6
10.8
C 60/40
955
1750
900
1650
510
950
4.7
8.4
C 85-55-5
1035
1900
930
1710
515
960
4.7
8.4
Pb
315
600
280
540
120
250
2.1
3.8
th ab b h rcndd va fr “s”. N a ha “s” i nrd in h formula as a whole percent, with no decimal point.
Sustd Prct Sds “S” (us r vus fr d fis) Wall thickness (inches) Al Mg
Zn
.01-.03”
5%
10%
5-15%
.03-.05”
5-25%
5-15%
10-20%
.05-.08”
15-35%
10-25%
15-30%
.08-.125”
20-50%
20-35%
20-35%
Fr pica ain cain ih a crcia nih, h va fr “s” i b bn ab 20 and 50. A prcna b 20 i ndd n fr h vr hin a cain, hi a prcna
GATING MANUAL
STEP 3 – DETERMINE THE SEGMENT VOLUMES, CAVITY FILL TIME, AND CAVITY METAL FLOW RATE
fr “s” f ab 20 35 i r fr pica cain ih a a hicn vr ab .125 inch and p. th r va d b d fr a br nih, r fr a nr a fl pah. on facr n incdd in h i fra i h a fl dianc. thi i h dianc f h pah h a a rach h a pin , r h nd f rav fr h n r cain ara f cncrn. th pah incd dflcin and an fl pah, and i n ncari the shortest distance. whi h abii fl hrh n dianc i drind b h avra a hicn an h fl pah, hr facr ha ac h abii f h a fl n dianc ar: h di prar, h a prar, and h a vci a h ar f h fl. An pirica id fr vaain fl dianc and a hicn i divid h fl dianc b h avra a hicn an h fl pah. thi i a rh idin a i a h di temperature, the metal temperature, and the ingate velocity are within typical operating ranges. Fr ain, if hi nbr i b ab 150, hn h fl dianc hd n b a bi facr. If h nbr i bn 150 and 300, hn hr i b incrain difc in ain h par and h i nd b p hr in rdr a h par. If h nbr i vr 300, i cd b vr difc a h par vn ih a hr i. N ha h nbr ar apprxia and ar inndd hp h dinr b aar f pnia prb ih a n fl dianc in chin h cavi i. Fr hin a par, h hr i rqirn i frc hih a vcii. th fin xap h h h fl dianc nbr and a adjn. An ain pan d in a brad-ain achin ha a .080 inch a ih a fl dianc f 23 inch. th a i dircd p n id and dn h hr. th di rn cd (400°F r 204°C) bca f h hin a, a v, and n h i. th nra cd va fr cacain i fr a a hicn f ab .080 and an “s” f ab 15% d caca a i f .026 cnd. th fl dianc nbr i 287, hich indica ha hi i a difc par ha hd hav a ini i. thi cd b dn b rdcin “s” h ini f 5%, hich d iv a i .017 cnd. thi i i cnrd b hirica daa, hich a i f han .020 cnd i ndd, a a axi i f .017 cnd i d. th chan in i i n .009 cnd. Hvr, h prcn i dcra f 38% i inican. A pradh can b d caca h i fra. NADCA prvid a cavi i prad h in h gain ca.
GATING MANUAL
STEP 3 – DETERMINE THE SEGMENT VOLUMES, CAVITY FILL TIME, AND CAVITY METAL FLOW RATE
Fr h prc ninr, hr i b dicrpanc bn h cacad va f i and h va an fr a pica nirin . th i va an fr a nirin incd h pnr’ dcrain i, hi h cacad i fr h fra i a hrica va ha a ha h pnr pd a cnan hrh . ua h rfac nih i drind in h r par f h hn h pnr pd i hih. thi i h pd ha i ipran fr a d nih, and hi i h pnr pd ndd h i cacad fr h hrica axi i cacain. The compaction of the metal in the cavity is done while the plunger slows down, and this portion priari ac h inrna pri rahr han h rfac nih. th, fr pracica prp, h pnr pd drin h r par f cavi hd ach h cavi cacain. If a paria ndr pd cndiin i bin d a a a rdc pri fr hic ad cain, hn i i difc ar. I a a b difc a d rfac nih bca f h n i ap drin h pr cndiin. th i cacain fr h fra can b accra if car i d in cin h va. exprinc ih fdbac fr cain flr daa i iprv h r. thi cacain hd b dn fr vr a din r. th fin ab i f fr picin a cavi i. th ab i bad n h cavi i fra. If in db ab a i , h char va and rdc i b 25%.
Average Wall Thickness (Inches)
Zinc 3,5,7
Fill Times in Seconds Aluminum
Magnesium
0.01 - 0.03
<.015 - <.020
0.04 - 0.05
0.02 - 0.026
0.0173 - 0.0417
0.0132 - 0.0209
0.06 - 0.08
0.0245 - 0.0529
0.0296 - 0.0845
0.0221 - 0.0413
0.09 - 0.125
0.0468 - 0.085
0.0553 - 0.1458
0.0366 - 0.0707
0.13 - 0.15
0.075 - 0.125
0.0956 - 0.2082
0.0579 - 0.0997
GATING MANUAL
FLOW RATES givn h n v and cavi i, h fl ra fr ach n and fr h entire casting can be calculated.
Qi = Vi / t whr, Qi = fl ra f a n (in3/c) Vi = v f a n v (in3) = cavi i (c), and Q = ∑( Qi) = fl ra fr h nir cain (in /c) This data is entered into the gating spreadsheet.
GATING MANUAL
4
STEP 4 – MATCH THE PROCESS TO The Flow RaTe.
PROCESS FACTORS AND LIMITS Fr h di cain achin() inndd ca h par hr ar parar chic. th casting pressure and fast shot velocity limit can be changed by changing the accumulator pressure. The fast shot velocity can be changed with the shot valve. There are ranges of plunger tip diar avaiab ha id varin a prr and fl ra. wha accar prr, and v/pnr ip diar hd b d aif h fl ra cacad in sp 3 (cavi i) and addr h prr i fr sp 1 (qai rqirn). A a ch plunger tip diameters is make a spreadsheet showing the options. Rqird F Ra = xxx in3/sec, Dird a prr = x.x ts/2 Accar prr = xxx lb/in3
Plunger (in)
Plunger Area (in2)
Required Fast Shot Velocity (in/sec)
Final Metal Pressure (tons/in2)
x.xx
xx.x
xxx
x.x
x.xx
xx.x
xxx
x.x
x.xx
xx.x
xxx
x.x
x.xx
xx.x
xxx
x.x
To do the spreadsheet the relationship between the accumulator pressure and the metal pressure needs to be known. This information can be obtained from the machine’s manual for the inndd di cain achin. onc h char i cnrcd chic can b ad. A di cain achin ha a nra ran and axi ii fr h fa h vci. thi infrain c from process engineering. 100 in/c, hn 80% r 80 in/c hd b d in h ain anai. th iv i room if more fast shot is needed to make the part than the gating analysis indicates. The other facr a i na a prr. Fr nra ain cain 4 n/in2 innid prr i d. If pri i a qai i r a in i rqird, hn 5 n/in2 na a pressure should be used. th r qin a hn rviin h pradh i can h achin divr h fl ra rqird. If h achin can n divr h fl ra, hn anhr achin nd b fnd r h cavi i in Step 3 needs to be increased.
GATING MANUAL
STEP 4 – MATCH THE PROCESS TO The Flow RaTe.
Ain h achin can divr h fl ra, hn c a pnr diar ha iv a d fr fa h vci and na a prr. ohr i cnidr in ain hi analysis are: Can h di cain achin hd h a a h prpd na a prr? wha i b h nna n ach i bar ih h prpd di din and cain prr? If h achin can’ hd h a, hn rfac nih and pri qai andard i b difc rard f h qai f h ain . Can h accar prr b rd and i hav fcin fa h vci? Cain h part with the least amount of pressure and fast shot velocity allows the die cast machine to run more smoothly with less mechanical stress and strain. This is a cost savings opportunity for die car h nra h injcin and di c prr h axi rard f h part being cast. In chin a pnr ip diar, ha i h pr cn f h v b. th rar h pr cn , h air nd b vnd and h r h prbabii fr rappd rida air a h nd f h h. In addiin, a hihr prcn v cnrv ha ih a temperature drop from the furnace to the ingate. th prc dciin a appar b cpicad. Hvr, if h ain dinr n h capabiii f h inndd achin() and iv hh h rad f cain prr, fa h vci, and v pr cn , hn inin chic ar ad and h gating system is engineered to work for the intended machine. The objective at this point is to n ha h di cain achin can divr h cain fl ra cacad in sp 3 and a pressure in the cast of porosity from Step 1 without undo stress to the machine. If h achin can’ divr h dird fl ra and a prr, hn h cavi i has to increase or a more powerful machine used.
GATING MANUAL
STEP 5 – DETERMINE THE INGATE PARAMETERS AND CHECK FOR aToMizeD Flow.
5
th nx p in h ain anai i cnin in p a pradh b n ih fl ra (Q), ina vci (V), apparn ina ara (Aa), fl an (Af), aca ina ara (A), ina nh (l), ina hicn (t), and aiain facr (J).
Segment
F Rt (in3/sec)
Ingate Velocity Apparent Ingate (in/sec) Area (in2)
F (deg)
Ingate Area (in2)
x
xxx
xxx
x.xx
xx
x.xx
x
xxx
xxx
x.xx
xx
x.xx
x
xxx
xxx
x.xx
xx
x.xx
Totals
xxx
Segment
x.xx
F Rt (in3/sec)
Ingate Velocity (in/sec)
Ratio Length/ Thickness
Atomization Factor
x
x.xxx
x.xxx
xx
xxxx
x
x.xxx
x.xxx
xx
xxxx
x
x.xxx
x.xxx
xx
xxxx
SEGMENT FLOW RATE th nbr c fr sp 3.
INGATE VELOCITY th ain dinr ch an ina vci fr h cain. Nra ran fr ina velocities are shown in the following chart. The ingate velocity selected should fall within these ranges.
Alloy
Normal Ingate Velocity (in/sec)
Aluminum
700 to 1600
zinc
900 to 2000
mani
1000 to 2000
GATING MANUAL
STEP 5 – DETERMINE THE INGATE PARAMETERS anD CheCk FoR aToMizeD Flow.
Hihr vcii ar chn fr hin ad cain ha rqir a d rfac nih, hr h travel from the near to the far end of the casting is long, or where the geometry is complicated and h a i ncnr dflcin. whn in hihr vcii r achin pr i b rqird and di rin arnd h ina i ccr nr. lr vcii i rqir achin pr and di rin arnd h ina i ccr ar. lr ina vcii ar r cnica in pr and r ainnanc and replacement costs. th, chin an ina vci ha d ih h qai rqirn and h r f h cain. Hirica a vci daa d b hpf fr h ain dinr. trb ccr when the chosen ingate velocity is not within the recommended range. The ingate velocity may b chand fr dirn ain cnari. lar in h anai h ina vci in cbinain ih h ina hicn i d fr aid fl.
APPARENT INGATE AREA The apparent ingate, Aapp, for each segment is calculated. Aappi = Qi / V whr, Aappi
= apparn ina ara f a n (in2)
Qi
= fl ra f a n v (in3/c)
V
= ina vci (in/c), and
These numbers are calculated in the spreadsheet.
FLOW ANGLES th a fl in ach n a an, hich i ard fr an axi prpndicar h parin in and can ran fr 0 45 dr. F an f an xiin cain can b brvd in a cd ar p h. In sp 1 h fl pan a viaid. thi pan incdd pcic fl an in ach n. th fl an ar nrd in h pradh.
ACTUAL INGATE th a vci a an an cin h ina can b rprnd a a vcr ih anid and dircin. thi fl vcr can b brn in vcr, n nra h ingate and one parallel to the ingate. The vector normal to the ingate represents the metal aca in in h di. th nra vcr = C(θ) * fl vcr and i irad a f:
8
GATING MANUAL
STEP 5 – DETERMINE THE INGATE PARAMETERS anD CheCk FoR aToMizeD Flow.
To arrive at the actual ingate area for each segment we use: Agi = Aappi / C (θ), and Ag
= ∑ (Agi)
whr, Agi
= aca ina ara f a n (in2)
Aappi = apparn ina ara f a n (in2) θ
= fl an ra f h n (d)
Ag
= a ina ara (in2)
These numbers are calculated in the spread sheet.
INGATE LENGTH & THICKNESS The ingate area is the product of the ingate length and the ingate thickness. Agi = lgi * tdi whr, Agi
= aca ina ara f a n (in2)
lgi
= ina nh f a n (in)
Tgi
= ina hicn f h n (in)
Perhaps the ingate length is known or desired from Step 1. Then Tgi = Agi / lgi. Perhaps we hav a dird ina hicn, hn l gi = Agi / tgi. Perhaps for a particular scenario we have a compromise between the two. These numbers are entered and calculated in the spreadsheet.
GATING MANUAL
9
STEP 5 – DETERMINE THE INGATE PARAMETERS anD CheCk FoR aToMizeD Flow.
RaTio ingaTe lengTh: ThiCkneSS If h rai f h n ina nh h ina hicn nh i han 10, hn h ingate depth should be corrected. lgi / tgi
> 10
whr, lgi
= n ina nh (in)
Tgi
= n ina hicn (in)
thi cndiin d n ccr vr fn. Diribin h fl vr a ar ara f h cain normally yields length to thickness ratios much higher than 10.
GATING MANUAL
STEP 5 – DETERMINE THE INGATE PARAMETERS anD CheCk FoR aToMizeD Flow.
INGATE VELOCITY th ina vci rqird in di cain i ch dirn han ha rqird fr hr cain prc. In hr prc ch a prann d, h a i rdc rbnc rdc rappd a. th cavi i d and rqir a hic a and a. Di cain hav relatively thin walls, thin gates, and rapid heat absorption by the die steel. Cavi in di cain di i fa ih a ran f 10 150 iicnd. Inad f a id fl front as in permanent mold, the die casting process sprays the metal into the die. In prann d h a fl hh a ar a i a id frn ih ainar fl. A h a vci hrh a ar a i incrad, h a frn bra p and h fl cni f cr and raiv ar paric. thi i cad h cr paric ran. In di cain, cr paric ran fl prdc qinab cain ih xciv inrna pri and pr rfac nih. A h a vci i incrad frhr, hr i a pin hr aid fl h ina bin. th cr paric ar brn p and h ra f a cni f n paric a vr hih vcii. whi hi vr rbn fl a appar b ndirab fr rappd a, i i h fl prdc ccf di cain. In di cain, h ina and h prc ar ninrd divr aid a fl h cavi.
If a dribb hrh h a bfr h fa h rach i rina vci, h a a prar fr a h a r in h cavi. thi i ca cd fl and laminations. Thus, the metal velocity should be accelerated early enough through the runner ha h a i a i na vci bfr i rach h a and h a i atomized through the gate. In ca, an praina in i b d ch ha h cavi i paria d (a ab 10% 15%) ih vci, and hn h a i accrad aid fl vcii. thi i dn rdc rappd a pri. whr hi i ccf, hr i a raiv hic a (greater than .160 in., or 4 mm) and thick gate, and the gate is on the bottom of the casting going in a hicr a cin. thi prc in fr paria ndr rbnc cndiin can sometimes generate a reduction in gas porosity. The gate design, however, should be done for the andard aid fl cndiin vn if i i xpcd ha h paria prc in i b used.
GATING MANUAL
STEP 5 – DETERMINE THE INGATE PARAMETERS anD CheCk FoR aToMizeD Flow.
on cain, i i pib hav a vr ar a, and h cain ih nnrbn fl. thi i n prvid hih qai rfac nih, b hn cbind ih h hihprr capabii f h pica di cain achin, i can prvid xcn inrna qai. thi chniq i cad q cain, ahh hr can b an dirn vrin f h fa hd. th vr n i d in f h hd an ha h a hicn b rar han pica di cain and h rfac nih rqirn ar n a d. th hd a r in vr hih di prar ha hrn di if. thi chniq pica a prr fr 15,000 25,000 b/in2. wih carf f di cain, i can b dn ih h r cn irn a ch a h 356 r 357 a. th nn-rbn and vr gas porosity results in a casting that can be heat treated or welded with the potential for higher elongation and some increase in tensile strength after heat treating. th chniq ar n dn fn nh ha h in bn q cain and rar di cain i ha brrd. A cbinain f vr ar a, vci a h ar and hihr vci fr h na i r fr par hap. Hvr, h a din chniq prnd hr ar fr cnvnina di cain and aid fl. th cacain f h ini a vci ndd rach h aid fl rin can b done from the following formula, which was developed from some earlier research.
Vg1.71 * Tg * p > J whr, Vg
= h ina vci (in/ c)
Tg
= h ina hicn (in)
p
= th dni f h a (b/in2)
J
= h aiain facr
Va f J ar bad n xprina r in cppr a. e. A Hran caca “J” fr ach alloy as:
Alloy
J Factor
mani
275
Aluminum
400
zinc
475
m prpd ain i hav a J Facr abv h ini. Indr pracic a vcii and hicn’ ha id a ini J Facr f 750 hich i cnrvaiv and is recommended for normal gating analysis. The following table shows the relationship of gate hic n and a vci if 750 i d in h aiain qain.
GATING MANUAL
STEP 5 – DETERMINE THE INGATE PARAMETERS anD CheCk FoR aToMizeD Flow.
Aluminum
Zinc
Magnesium
ga thicn
mini Vci
ga thicn
mini Vci
ga thicn
mini Vci
Inch
mm
in/c
/c
Inch
mm
in/c
/c
Inch
mm
in/c
/c
0.030
0.762
1497
38
0.006
0.152
2312
59
0.012
0.305
3212
82
0.035
1.016
1368
32
0.008
0.203
1954
50
0.015
0.381
2819
72
0.040
1.143
1265
30
0.010
0.254
1715
44
0.020
0.508
2382
60
0.045
1.270
1181
28
0.012
0.305
1542
39
0.024
0.610
2141
54
0.050
1.397
1110
27
0.013
0.330
1471
37
0.028
0.711
1957
50
0.055
1.524
1050
25
0.014
0.356
1409
36
0.032
0.813
1810
46
0.060
1.651
998
24
0.015
0.381
1353
34
0.036
0.914
1689
43
0.065
1.778
952
23
0.016
0.406
1303
33
0.040
1.016
1588
40
0.070
1.905
912
22
0.017
0.432
1258
32
0.044
1.118
1502
38
0.075
2.032
876
21
0.018
0.457
1216
31
0.048
1.219
1428
36
0.080
2.159
843
21
0.019
0.483
1178
30
0.052
1.321
1363
35
0.085
2.286
814
20
0.020
0.508
1144
29
0.056
1.422
1305
33
0.090
2.413
787
19
0.021
0.533
1111
28
0.060
1.524
1253
32
0.095
2.540
763
19
0.022
0.559
1082
27
0.064
1.626
1207
31
0.100
2.794
740
18
0.023
0.584
1054
27
0.068
1.727
1165
30
0.110
3.048
700
17
0.024
0.610
1028
26
0.072
1.829
1126
29
0.120
3.302
665
16
0.026
0.660
981
25
0,076
1.930
1091
28
0.130
3.556
635
15
0.028
0.711
939
24
0.080
2.032
1059
27
0.140
3.810
608
15
0.030
0.762
902
23
0.084
2.134
1029
26
0.150
4.064
584
14
0.032
0.813
869
22
0.088
2.235
1002
25
0.160
4.572
562
13
0.034
0.864
838
21
0.092
2.337
976
25
0.180
5.080
525
13
0.036
0.914
811
21
0.096
2.438
952
24
0.200
5.842
494
12
0.040
1.016
762
19
0.100
2.540
930
24
0.230
6.604
455
11
0.045
1.143
712
18
0.150
3.810
733
19
0.260
7.620
423
10
0.050
1.270
669
17
0.200
5.080
620
16
0.300
8.890
389
9
0.060
1.524
602
15
0.250
6.350
544
14
0.350
10.160
356
8
0.070
1.778
550
14
0.300
7.620
489
12
0.400
11.430
329
8
0.080
2.032
508
13
0.400
10.160 413
10
0.450
11.430
307
8
0.090
2.286
475
12
0.450
11.430 386
10
0.500
12.700
289
7
0.100
2.540
446
11
0.500
12.700 363
9
th J facr i cacad in h pradh and cpard h ini rqird drin if h prpd a vci and a hicn i prdc aid a. If J i less than the minimum, then the gate thickness or the gate velocity needs to be increased. If an nbr fa f nra rcndd ran ch a an ina hicn f .023 inch fr ain, r a nh, hich xcd h avaiab ina nh a h parin in, hn chan nd b ad. Prhap h fl pan, h nain, h cavi i, r ina vci nd b chand and anhr cnari nrad. Din an cnari i nra fr h ain din prc ni h b cpri ar ad. whn h iar d a ain project, scenario after scenario will be run until the design is considered optimized. The same process occurs when doing unsimulated gating design.
GATING MANUAL
STEP 5 – DETERMINE THE INGATE PARAMETERS anD CheCk FoR aToMizeD Flow.
A special gating case occurs with long castings and small casting volumes such as chrome plated aiv bd id din. In hi ca h ina i caca b vr hin bca f h n ina nh and a cavi v. Ina vcii xcdin h nra ran d be needed to atomize the metal. This would demand high machine power and would erode the ingate die steel if attempted. This remedy for this case is comb gating.
At this point in the gating analysis the ingate width and length have been determined. The a vci i ihin h nra ran. th fl i aid, and i i nn ha h inndd achin can divr h fl ih a chn pnr ip.
GATING MANUAL
6
STEP 6 – DO A PQ 2 ANALYSIS IF DESIRED
th a f h PQ2 anai i ach h di’ dind ain h achin’ a hdraic . In h anai P and fr a prr and Q and fr a fl ra. th n a fl ra hrh an ric ch a an ina i a fncin f h prr n h n a - h hihr h prr, h hihr h fl ra. Hvr, h rainhip f prr and fl ra i n inar. th vrnin qain fr flid fl hrh an ric r ina i Brni qain.
Pm = ( ρ / 2 ) * ((Q / (a g * Cd ) ) 2 whr, Pm
= a prr (b/in2)
ρ
= a dni (b/in3)
= raviaina cnan (in/c2)
Q
= a fl ra (in3/c)
Agapp = apparn ara f h ina (in2) Cd
= cfcin f dichar
th xprin in Brni’ qain (Q / Ag) i qa h ina vci Vg. s h qain can also be written as: Pm = ( ρ / 2 ) * ((Vg / Cd ) ) Fr brvain f h Brni’ qain: ma prr rqird i dirc prprina a dni. Incrain h a prr incra h fl ra. Dcrain h a prr dcra h fl ra. th rainhip i nn-inar. Incrain h apparn ina ara, Agapp, decreases metal pressure, P m ndd. Dcrain h ina ara incra h rqird prr. th rainhip i nn-inar. Incrain h cfcin f dichar, Cd, ih a r fcin a and hdraic dcra h prr rqird. Dcrain h cfcin f dichar ih a r infcin a and hdraic incra h prr rqird. th relationship is non-linear.
GATING MANUAL
STEP 6 – DO A PQ2 ANALYSIS IF DESIRED
Incrain h a prr, incra h ina vci, V g. Dcrain h a prr, dcra h ina vci rqird. th rainhip i nn-inar. Va d fr iqid dni ar: Ain
= .093 b/in3
zinc
= .221 b/in3
mani = .063 b/in3 th raviaina cnan “” i 32.2 f/c2, r 386.4 in/c2 th cfcin f dichar (Cd) i a ar f infcinc f h a divr and achin hdraic . I i h rai f h fl in h aca achin and di an ida flid that has no friction. Cn va fr Cd for die casting applications are: Cd chabr ain = .45 .5 Cd chabr ani = .45 .5 H chabr inc r a = .55 .65 th fin raph h h nn-inar rainhip bn a prr and fl.
spcia raph papr ih a nn-inar Q 2 ca a h P and Q 2 relationship linear.
GATING MANUAL
STEP 6 – DO A PQ2 ANALYSIS IF DESIRED
th PQ 2 gating analysis using graph paper or a computer generated graph is: 1.
obain h apprpria PQ 2 graph paper for the machine and die to be analyzed.
2.
Drin h accar prr and cnvr h accar prr a prr fr a cd pnr diar. P h a prr n h PQ 2 graph paper n h vrica axi (Q 2 = 0). t nd h a prr fr h accar prr: P = ((Ph * Ah) – (Pr * Ar)) / Ap) whr, P
= a prr (b/in2)
Ph
= h cindr had id prr (b/in2)
Ah
= ara had id (in2)
Pr
= h cindr rd id prr (ib/in2)
Ar
= ara rd id (in2)
Ap
= ara pnr (in2)
The values for the head side and rod side areas are in the machine manual. The pressures can be read from gages on the machine.
GATING MANUAL
STEP 6 – DO A PQ2 ANALYSIS IF DESIRED
3.
Find r drin h dr h fa h vci a h accar prr chn and p n h hrina axi (P = 0). th va fr h dr h pd fr given accumulator pressures pressures can be found in the machine manual or can be determined xprina n h flr.
4.
Dra a raih in bn h pin f Steps 2 and 3. thi i cad h machin Prfranc lin.
5.
A a cfcin f dichar.
6.
sc an ina vci. Caca h a prr rqird prdc hi vci. sc an ina ara. Caca h fl ra aciad ih hi ina ara and ina vci (Q = Vg * Ag). P hi pin n h PQ^ raph fr h riin. Dra a raih in hh hi pin. thi i cad h Di Rianc lin fr h cd ina vci and ingate area.
7.
th inrcin f h Di Rianc Rianc lin and h machin Prfranc lin i axi operating condition for the parameters selected.
8
GATING MANUAL
STEP 6 – DO A PQ2 ANALYSIS IF DESIRED
mini ga Vcii fr J = 750 Aluminum Gate Minimun Thickness Velocity
Zinc Gate Thickness
Minimun Velocity
Magnesium Gate Minimun Thickness Velocity
Inch
mm
in/c
/c
Inch
mm
in/c
/c
Inch
mm
in/c
/c
0.030
0.762
1497
38
0.006
0.152
2312
59
0.012
0.305
3212
82
0.035
0.889
1265
32
0.008
0.203
1954
50
0.015
0.381
2819
72
0.040
1.016
1181
30
0.010
0.254
1715
44
0.020
0.508
2382
60
0.045
1.143
1110
28
0.012
0.305
1542
39
0.024
0.610
2141
54
0.050
1.270
1050
27
0.013
0.330
1471
37
0.028
0.711
1957
50
0.055
1.397
998
25
0.014
0.356
1409
36
0.032
0.813
1810
46
0.060
1.524
952
24
0.015
0.381
1353
34
0.036
0.914
1689
43
0.065
1.651
912
23
0.016
0.406
1303
33
0.040
1.016
1588
40
0.070
1.778
876
22
0.017
0.432
1258
32
0.044
1.118
1502
38
0.075
1.905
843
21
0.018
0.457
1216
31
0.048
1.219
1428
36
0.080
2.032
814
21
0.019
0.483
1178
30
0.052
1.321
1363
35
0.085
2.159
787
20
0.020
0.508
1144
29
0.056
1.422
1305
33
0.090
2.286
763
19
0.021
0.533
1111
28
0.060
1 .524
1253
32
0.095
2.413
740
19
0.022
0.559
1082
27
0.064
1.626
1207
31
0.100
2.540
700
18
0.023
0.584
1054
27
0.068
1.727
1165
30
0.110
2.794
665
17
0.024
0.610
1028
26
0.072
1.829
1126
29
0.120
3.048
635
16
0.026
0.660
981
25
0.076
1.930
1091
28
0.130
3.302
608
15
0.028
0.711
939
24
0.080
2.032
1059
27
0.140
3.556
584
15
0.030
0.762
902
23
0.084
2.134
1029
26
0.150
3.810
562
14
0.032
0.813
869
22
0.088
2.235
1002
25
0.160
4.064
525
13
0.034
0.864
838
21
0.092
2.337
976
25
0.180
4.572
494
13
0.036
0.914
811
21
0.096
2.438
952
24
0.200
5.080
455
12
0.040
1.016
762
19
0.100
2.540
930
24
0.230
5.842
423
11
0.045
1.143
712
18
0.150
3.810
733
19
0.260
6.604
389
10
0.050
1.270
669
17
0.200
5.080
620
16
0.300
7.620
356
9
0.060
1.524
602
15
0.250
6.350
544
14
0.350
8.890
329
8
0.070
1.778
550
14
0.300
7.620
489
12
0.400
10.160
307
8
0.080
2.032
508
13
0.400
10.160
413
10
0.450
11.430
307
8
0.090
2.286
475
12
0.450
11.430
386
10
0.500
12.700
289
7
0.100
2.540
446
11
0.500
12.700
363
9
GATING MANUAL
9
STEP 6 – DO A PQ2 ANALYSIS IF DESIRED
PQ 2 NOTES 1.
Cavi i i a fncin f fl ra. th ini fl ra fr a dird axi cavi i can b pd n h PQ2 diara a a vrica in. oprain cndiin must be to the right of this line.
2.
Fr an inndd ina hicn, hr i a ini ina vci ndd ai h a fr an inndd ina hicn. Fr Brni’ Brni’ qain a prr can b cacad fr hi ini vci. thi can b dran a a hrina in. oprain conditions must be above this line. The horizontal, horizontal, vertical, and machine performance performance lines create an area that can be called the operational window. The die should operate in this dnd ara.
3.
ec f Parar Chan Rdcin r incrain h accar prr cra para machin Prfranc lin n h PQ2 raph.
GATING MANUAL
STEP 6 – DO A PQ2 ANALYSIS IF DESIRED
Cin h h vav ha h c f crain machin Prfranc lin ha piv fr h a prr pin ih r fl. thi daa can c fr h achin’ b r b drind xprina.
Chanin h pnr ip ha h c f chanin h p f h machin Prfranc lin. sar pnr id hihr a prr and fl. larr pnr id r a prr and r fl.
Chanin h ina ara chan h p f h Di Rianc lin. sar ina ara id r prr, fl. larr ina ara id prr, r fl.
GATING MANUAL
STEP 6 – DO A PQ2 ANALYSIS IF DESIRED
Fr a h pin an machin Prfranc and Di Rianc lin can b dran h h prain cndiin fr a ivn f ain parar. man cnari ar rn. th bjciv i nd a cbinain f ina ara, ina vci, ina hicn, pnr ip diar, and accar prr ha cra a ar cnra praina ind n h PQ 2 diara. NADCA prvid far hp ih h PQ 2 analysis and calculations. th PQ 2 anai can b rn a a chc n h cnvnina ain anai r vic vra. N h cfcin f dichar appar a a qard r in Brni’ qain hich an a a pr cn chan in hi nbr r in a inican pr cn a prr chan a hr facr bin qa. th achin’ prfranc and hr chanica i ch a h ainn f h v and pnr chan hrh i. th facr ac h cfcin f dichar. scin a cfcin f dichar n h id i a cnrvaiv apprach.
GATING MANUAL
7
STEP 7 – DESIGN THE FAN AND TANGENTIAL RUNNERS
FLOW AREA CONSIDERATIONS th fncin f h rnnr i divr h a h ina and nra h dird fl pattern within the cavity segments. There are three runners used plus the chisel runner that is sometimes used in dealing with local porosity. The three runners are the straight fan, the curved fan, and the tangential runner. th ina cnr h a fl in h cavi. thrfr, h ina ha h a ara in h a fl pah fr h bici r pr h cavi. If hi r n r, hn hr far in h rnnr i cnr h a fl ch a an ndrid rnnr r an undersized nozzle on a hot chamber machine. Rnnr hd aa b dind arin a h ina and rin bac h pr or biscuit and in the case of hot chamber machines working back to the gooseneck plunger. At this point in the analysis the ingate areas and locations are known so the runner design starts at the gate opening and works backwards to the sprue or biscuit. The runner area should decrease as the runner transitions into the gate. This not only maintains h a a h a ara in h fl pah, b i a frc h a fl prad h f idh f h a and h a d ha i a dind d. Dcrain h rnnr ara adin p h ina a prvn ixin air ih h a in h rnnr ha ih h p in the casting as porosity. sarin a h a, h rnnr i b arr han h a. th rai f h rnnr a ara i var ih h din, and i a ran bn 1.1:1 and 1.4:1. Hvr, i can b larger as in the case of small castings where using a ratio of 1.4:1 would result in too much metal heat loss in the fan or tangential runner system. Thus, if the gate area is 1.00 in 2, then the runner ara hd b bn 1.1 and 1.4 qar inch xcp in a cain. The ratio is determined by several design factors, and it important to realize that there isn’t a aic nbr ha appi a circanc. s f h facr cnidr ar:
ALUMINUM tpica rai i b ab 1.1 1.4. th hihr rai ar d hr hr i a arr fl an. A fl an rar han 35° fr a fan a din i rqir a rai f 1.3:1 r rar. A fl an f 10° 35° d b accpab ih a a rnnr rai f ab 1.1:1 1.3:1. Hihr fl an rqir r rricin frc h a cnfr h a hap.
GATING MANUAL
STEP 7 – DESIGN THE FAN AND TANGENTIAL RUNNERS
on h hr hand, h dinr hd b cai ab in ar rai fr ar cain bca h ain rnnr h bici r pr a p bin xciv ar. Rnnr dn’ hippd. Rnnr n add h nr and dr c f h pan. In pan, i i cn a p 45o ramp for the transition from the fan or tangential runner to the gate. The thought is to keep the metal hot up to the gate to prevent prar frin f h ina. Hvr, frin a h a can a b crrcd ih prc chan, and hi ind f a din hd n b ncar. I can b d in ca hp pcic pri p, b i frc h a accra in a vr hr dianc and a n a h a prad h d f h a. If hi a din chniq i d, hn i i d ha h a rnnr rai i nd b qi hih, pica 1.5:1 r even 2:1.
ZINC thinnr a and ar a ar d in inc ih rnnr a a a .125 x .125 inch r vn ar in fr id achin. th ar rnnr rqir a vr fa i ( han 10 msec) to stay open. th rnnr i rai i fn 1.05 1.15 i h a ara. th ar ar incra han those used in aluminum, partly because the area of the sprue or the nozzle feeding the sprue ii h axi ara f h rnnr in a h chabr achin. whn hi ccr, f h avaiab ara rdcin hd b d a h a, hich a mean that the runner components will be designed with a small area reduction from the sprue start of the gate. The sprue and nozzle areas need to be reviewed in all hot chamber designs along ih h rnnr cpnn. si h n r pr i ar han i hd b. A d din in a b a rnnr pr, hich i prvid rricd fl and can support a bigger runner system.
MAGNESIUM mani rnnr r ih r pd han hr a. Hih rnnr pd i dirab to keep the heat loss down, which is critical in magnesium where the latent heat and the pcic ha ar . Ahh in h a ra a in ain i iab fr di, smaller runner sizes and higher velocities can be an advantage. The concept is to keep the runner velocities high with modest area increases from the ingate to the sprue or biscuit to minimize heat loss in the runners.
GATING MANUAL
STEP 7 – DESIGN THE FAN AND TANGENTIAL RUNNERS
FAN RUNNERS Fan rnnr can b d fd h nir cain r pi h a fr a ain rnnr adjacn annia rnnr. Fan nra a dirab rn cnr . thr ar p f fan – a crvd idd fan and a raih idd fan. In rdr fr h fan hav cnan decreasing area from the main runner to the ingate, a curve sided fan’s depth will decrease inar, and a raih idd fan i hav a dph hich i crvd. If h fan i cnrcd ih straight sides and a linear depth reduction, then the fan area from the runner to the ingate will not decrease linearly though the fan. The metal will pull away from the sidewall and generate a pc. thi pc i fd a a f air bbb in h flin a and cnrib casting porosity. sraih and crv idd fan ar hn in h nx r.
GATING MANUAL
STEP 7 – DESIGN THE FAN AND TANGENTIAL RUNNERS
An inferior fan gate with straight sides and depth looks like the following.
th fla fan hap i ip a and a appar d ranab , b i i add a porosity to the casting. th advana f raih idd fan ar ha h fl an i nn and h rnnr bra can ih a ri di. th diadvana f a raih fan i i i r difc achin in the die. The fan should be modeled and edm’ed in. The advantage of a curve sided fan is that is easier to machine into the die. The disadvantages f h crv idd fan i h fl an i n car dnd and ha h fan d n bra cleanly and must be trimmed.
FAN FLOW ANGLES th fl an fr h raih idd fan i h an f h ida h cnrin. th raih idd fan din hn arir ha a fl an f 26°, hich i ard a hn b. th crvd fan a ha a fl an ard a a pin ¼ h dianc fr h a h runner, as shown below.
GATING MANUAL
STEP 7 – DESIGN THE FAN AND TANGENTIAL RUNNERS
th axi fl an fr an fan i 45°. th fl h nd f fan ih fl an rar han 45° i b niib.
th d f a crvd fan nd bra a hn b. If h par i hand dad r bd , i i rcndd ha h a idh b rdcd apprxia a hn ih h red dotted lines to address the break out issue.
GATING MANUAL
STEP 7 – DESIGN THE FAN AND TANGENTIAL RUNNERS
th fl an fr fan vari fr f cnr rih. th avra fan fl an d calculate the actual ingate area from the apparent ingate area is:
θ = ((θl + θr) / 4) + θc whr, θ = avra fan fl an θl = fl an f id f fan θr = fl an rih id f fan θc = fl an cnr f fan
DESIGNING FAN RUNNERS The procedure for designing a fan is: 1.
Drin h fan idh and h fan nh. th fan idh a scin A i h a idh as the ingate. The fan length is the distance from the end of the fan to the beginning of h fan, scin I, jinin h ain rnnr. th rai f h fan idh h fan nh drin h fan’ fl an a ach d. Incrain h fan nh dcra h fl angle at the fan’s edges.
2.
Divid h fan in qa cin fr binnin nd. A cnvnin nbr f cin to use is 9.
8
GATING MANUAL
STEP 7 – DESIGN THE FAN AND TANGENTIAL RUNNERS
3.
Drin h ara f h nd scin A. thi ara i qa r rar han h ina ara. I i car a h ara f scin A 10% rar han h ina ara i feeds. This gives some wiggle room if the ingates need to be increased slightly when the part is cast without having to reburn the fan to enlarge it.
4.
Drin h ara incra fr scin A h binnin f h fan scin I. In h xap h ara incra 200%. thi prcn incra i a jdn ca and i var ih ach cain. on n hand h bjciv i divr h a h ina, and n the other hand the objective is to minimize the size of the runners to reduce remelt costs.
5.
Drin h ara f ach cin ih a inar rdcin in ara fr h binnin f h fan nd f h fan. If 9 cin ar d, hn h ara f scin e i h avra f scin A and I. th ara f scin C i h avra f cin A and e, c.
6.
Drin dinin f h binnin f h fan, scin I. th ain rnnr dinin ha fd h fan and h dinin f scin I ar h a.
7.
Fr a crv idd fan, h fan dph inar dcra fr h binnin h nd. Drin h dph f ach cin ih a inar rdcin fr h binnin h end. The same method as in Step 5 can be used.
8.
Caca h avra idh f ach cin. thi i h cin ara dividd b h cin depth.
9.
Put all the fan data into a chart and draw a sketch showing the plan view and the crosscina vi f h fan. on h cr-cina vi h h rainhip f h fan in the ejector half and the ingate in the cover half overlapping the fan and the land distance.
The straight sided fan is done the same way only the width increases linearly from the fan beginning to end. The fan depth is calculated from the sectional fan areas and widths and will be non-linear.
FAN NOTES
GATING MANUAL
9
STEP 7 – DESIGN THE FAN AND TANGENTIAL RUNNERS
Crvd sidd Fan Daa tab it wdt = 5.000, it Tcss = .063, F a = 40 drs scin
Dianc
Area
Dph (h)
Av widh
Base (b)
Top (t)
sid (c)
sid (d)
A
0.000
0.347
0.069
5.000
5.012
4.988
0.012
0.012
B
0.750
0.408
0.136
3.009
3.033
2.986
0.024
0.024
C
1.500
0.470
0.202
2.326
2.362
2.291
0.036
0.036
D
2.250
0.532
0.268
1.981
2.028
1.934
0.047
0.047
e
3.000
0.593
0.335
1.773
1.832
1.714
0.059
0.059
F
3.750
0.655
0.401
1.633
1.704
1.563
0.071
0.071
g
4.500
0.717
0.467
1.533
1.616
1.451
0.082
0.082
H
5.250
0.778
0.534
1.458
1.552
1.365
0.094
0.094
I
6.000
0.840
0.600
1.400
1.506
1.294
0.106
0.106
h = Ara / dph Av widh = Ara / h b = Av widh + c = Av widh - c c = 0.176 * h d = 0.176 * h Ara Rai scin I:A 2.42
1.
The sides of fans have 10o draft. Any section of the fan is actually a trapezoid.
2.
Pannd fl ih aciad fl an a drind in sp 2. B chanin h fan nh raiv h fan idh, h fl an chan. Nra an fan cnari ar nrad h fl an dird and h fan h pac avaiab n h di. I i hpf hav pradh cnainin nric raih and crv idd fan ha fan din daa can b cacad qic and accra.
eihr p can b a an an dirc h fl ard a prb ara. th irain b h h hi can b dn. th r b a h h raih fan a a f rnd a a 30° an. th arr apprxia h n fl parn. thi a h fl b dircd at a particular problem area.
GATING MANUAL
STEP 7 – DESIGN THE FAN AND TANGENTIAL RUNNERS
FLOW PATTERNS FOR THE FAN GATES th fl parn nrad b h dirn p f fan a ar hn b h fin pictures:
GATING MANUAL
STEP 7 – DESIGN THE FAN AND TANGENTIAL RUNNERS
TANGENTIAL RUNNERS Tangential runners run tangent along the side of the cavity. The advantages of tangential runners are: ●
the runner is compact and can be kept close to the casting,
●
h fl dircin can b cnrd, and
●
hot metal can be distributed over a relatively long distance.
A diadvana f annia rnnr i ha rnnr i vr bi if a fl an ar desired. th annia rnnr fl an i drind b h rai f ina ara rnnr ara. A an pin in h annia rnnr h fl an i h arcann f h a ara dividd b h annia rnnr ara. Fr hi cacain, h a ara i h a a ara dnra fr the section selected, and the runner area is measured at the section selected.
Bca f h fl an, h a a ar a ara han ha aca c in h di. I a an h aca vci i hihr han h apparn ina vci.
Actual gate area = Apparn a ara / Cin (fl an) or
apprt t r = actu t r * Cs (fl )
And, actu t vcty = apprt t vcty / cs (fl ) where the Apparent gate velocity is calculated by using the plunger diameter, fast shot velocity, and measurements of the ingate.
GATING MANUAL
STEP 7 – DESIGN THE FAN AND TANGENTIAL RUNNERS
sinc h cin f h fl an i aa han n, h dirnc f h Aca and Apparn ina vcii can b inican. sdr and rin prb can ccr d nxpcd hih aca ina vcii pcia ih ain. th fin ab h h apprxia fl an aainab fr h annia rnnr. N ha a vr ar rnnr i ndd h a ih a fl an in h cain. If hi i h fl parn ha i ndd, hn a fan a a b r apprpria han h tangential gate.
Examples of Runner Area Gate Area
Ratio of Gate/Runner
F a Degrees
0.10
0.10
1.00
45.00
0.11
0.10
0.90
41.99
0.13
0.10
0.80
38.66
0.14
0.10
0.70
34.99
0.17
0.10
0.60
30.96
0.20
0.10
0.50
26.57
0.25
0.10
0.40
21.80
0.33
0.10
0.30
16.70
0.50
0.10
0.20
11.31
Pracica annia fl an var fr 26° 45°. A hc abrbr i dirab fr tangential runners. The shock absorber will prevent spitting of metal into the die at the end of h annia rnnr hn h rnnr i in. thi pr f a i vna rd h runner and the ingate at the end of the runner. The shock absorber allows the tangential runner and prri prvidin ian an h annia rnnr’ nh. A prpr dind hc abrbr i rap cprd air in h cnr. shc abrbr hd b fd annia cra a hirp fl parn ih air rappd in h cnr. An jcr pin hd aa b pacd ndrnah h hc abrbr. If hr i n jcr pin ndr h hc absorber, then the shock absorber will stick to the die. The diameter of the shock absorber should be large enough to create the air pocket in the center. The shock absorber diameter should be apprxia h qar r f h in ara h annia rnnr.
GATING MANUAL
STEP 7 – DESIGN THE FAN AND TANGENTIAL RUNNERS
The dimensions for the designed tangential runners are provided to the toolmaker of die designer with the above drawing, a data chart, and a generic tangential runner cross section.
GATING MANUAL
STEP 7 – DESIGN THE FAN AND TANGENTIAL RUNNERS
The aspect ratio is the ratio of the average width to the height of the tangential runner. A typical aspect ratio for tangential runners is 2:1. An aspect ratio of 1:1 would be more compact conserving heat. An aspect ratio of 3:1 would be more spread out and would dissipate more heat to the runner die steel. To calculate the dimensional data for each section: 1.
Caca h ara fr a cin xcp h a (scin J). th annia rnnr ara fr an cin i h ina ara ha i fd dividd b h cin f h fl an.
2.
Caca h, b, d, , and c fr ach cin xcp h a (scin J). th fra fr a 2:1 apc rai ar ivn in h xap.
3.
th annia rnnr a cin J fd an ina f r. Hvr, i i car a cin J a a a hic a h ina. If a hc abrbr i d, i nd b bi enough to feed the shock.
GATING MANUAL
STEP 7 – DESIGN THE FAN AND TANGENTIAL RUNNERS
Tangential runners do not have to be kept parallel to the edge of the casting with tangential a. th rap fr h rnnr h cain can b xndd hi p f a can fd an irregular edge. This is shown below.
GATING MANUAL
STEP 7 – DESIGN THE FAN AND TANGENTIAL RUNNERS
th rap fr h rnnr h cain can b nhnd a ndd h cain cnr. th rap ar a pd ab 5° fr h rnnr h cain (r h and if n i used). A id vi f h chniq i hn b.
thi chniq can a b d dirc h fl f a annia rnnr. th rnnr can b and a h fl parn in h dircin dird. The picture below shows a gate design where the tangential gate was shaped so as to direct the fl a paricar prb ara. th fl parn in hi ca rd v dfc problems.
GATING MANUAL
STEP 7 – DESIGN THE FAN AND TANGENTIAL RUNNERS
If i i dird hav a dirn an, i i pib an h rnnr aa fr h cain in rdr h fl an dircd br. th a can b addd h crvd cin f h annia a and h bain dirn fl an ha cd n b achivd ih a straight section. This is shown below, where the runner curves were used to direct metal into the crnr f h cain ha cd n b rachd ih in hi chniq.
thi chniq i vr prf, pcia hn a d rfac nih i rqird. thi xap a dn b cpr, b d i ana, h fin prcdr i a c apprxiain. Fir, h raih cin in h idd.
8
GATING MANUAL
STEP 7 – DESIGN THE FAN AND TANGENTIAL RUNNERS
n d t f stps: 1.
Dra h fl vcr a i i dird,
2.
Add a prpndicar h in apprxia in h ara h rnnr i xpcd b.
3.
thn add a in a an an h in fr p 2 f apprxia 30°. th nd f hi line should intersect the edge casting where the initial gate starts. The runner will then be a crv achin h xiin rnnr ha i ann hi in.
4.
Dra a prpndicar hi in dn in p 3, arin hr h in fr p 3 and h fl vcr inrc.
5.
Dra a vrica in fr h arin pin f h a fr h iniia raih cin.
6.
whr h in fr 4 and 5 inrc i h cnr f h radi frin h id f the new runner section.
th 30° i cd a a fl an ha i raiv a achiv, hi cd b an va ih in h ran f ab 30° 40°. thi crv d b h pah fr h rnnr ha d fl in h dircin f h vcr – if h rnnr r id prvid h fl an cd hn drawing the tangent line.
MAIN RUNNERS AND CAVITY LAYOUT main rnnr carr h a fr h pr r bici fan and annia rnnr. th rnnr i usually done in trapezoidal shape, although round runners are used for miniature zinc 4-slide machines. Rnd rnnr hd hav a raih cin addd a h parin in avid a ih ndrc. The width to depth ratio is called the aspect ratio, and will usually be between 1:1 and 3:1. The rfac ara v rai c hn h hn h dph i qa h idh, and hi i pica d fr rnnr. Hvr, in ar ain di hr h ain rnnr i get too large to freeze in a reasonable time, the runner depth is kept constant at about .7 inches and h idh i xpandd a ncar h rqird ara.
GATING MANUAL
9
STEP 7 – DESIGN THE FAN AND TANGENTIAL RUNNERS
th ipran cncp in rnnr din i ha h binnin f fl a h bici r pr must be the largest area, and that the metal encounters an ever decreasing area as it moves to h fan and annia rnnr. uia, h a ara in h divr i h ina ara and hi ara cnr h fl and vci in in h cavi n hr far f the runner system. Another factor to consider is the high velocity and momentum of the metal in the runner system. whrvr h a ncnr harp crnr rbnc can b crad cain a nrapn, which ends up as porosity or blisters. Thus, main runners turns should be smooth and gradual. Rnnr dn’ hippd. enr c p riin. exciv ar rnnr h cc time and increase energy costs. Therefore, the designer is encouraged to design the runner wisely.
RUNNER DESIGN PROCEDURE Rnnr din hd ar a h a and prcd h v r pr. th r p a covered earlier in the fan and tangential runner design, and should result in the initial runner size about 1.1 to 1.3 times the gate area. The main runners should be increased in size as the design prcd fr h fan and annia rnnr h pr r bici. each rn f raniin fr n ain rnnr hd hav an ara rdcin fr nranc xi. Prpr dind bnd nd n a a incra, a 3% ab 5%, dpndin n h harpn f h bnd. These small increases depend on having a good runner design, and a smooth model of the runner , prfrab n ha can b achind fr a CAD d. “ y” jncin hd a hav an incra in ara hn in pra fr h branch fr h ain rnnr n h rdr f 3% 10%. An incra f 5% fr d h hap hd b adqa. larr incra ar r cnrvaiv and r crain cvr rrr, hvr, h fn result in a large main runner that slows the cycle time. Tree runners are often used for multi cavity work. They are always a problem because the metal will not arrive at the top and bottom cavities at the same time. Tree runners violate the principle f ian and hd b avidd, a h p and b cavii i n rn h a crain qai prb. I i far br a di a ih cavii qidian fr h sprue or biscuit.
GATING MANUAL
STEP 7 – DESIGN THE FAN AND TANGENTIAL RUNNERS
six cavi di ar r difc, and a rqir inni, b h r i rh i.
GATING MANUAL
STEP 7 – DESIGN THE FAN AND TANGENTIAL RUNNERS
The design of main runners follows the same pattern as with fan and tangential runners. The cr cin f a ain rnnr nd b dnd fr h ar r h dinr. th aspect ratio of main runners is the ratio of the average width to the depth. Typical ratios are 1:1 3:1. Hr i a pradh xap f main Rnnr dinina daa. th h rnnr i dran n h priinar di hr h ain rnnr cin ar idnid.
GATING MANUAL
STEP 7 – DESIGN THE FAN AND TANGENTIAL RUNNERS
Main Runner Description Component
Description
1
Tangential
2
Fan
3
Fan
4
Fan
5
Fan
6
Fan
7
Fan
main Rnnr:
Apc Rai = 2:1
Main Runner Section
Feeding
Draf = 10
Area (in2)
Avg Width h (in) b (in) d (in) t (in) (in)
c (in)
e
1
0.237
0.688
0.344
0.748
0.061
0.627
0.061
I
An Fan
0.225
0.671
0.335
0.730
0.059
0.612
0.059
F
1+2
0.485
0.984
0.492
1.071
0.087
0.898
0.087
g
1+2+3
0.721
1.201
0.600
1.306
0.106
1.095
0.106
l
7
0.236
0.687
0.344
0.748
0.060
0.627
0.060
k
6+7
0.473
0.972
0.486
1.058
0.086
0.887
0.086
m
All
1.643
1.813
0.906
1.972
0.160
1.653
0.160
(Ara scin m = A = k + 2*I + g =1.643 )
main Rnnr dinin fra fr an apc rai f 2:1 h
=
(Ara / 2).5
b
=
2.176 * h
d
=
0.176 * h
=
1.824 * h
c
=
0.176 * h
GATING MANUAL
GATING MANUAL
8
STEP 8 – DESIGN THE OVERFLOWS AND VENTS
OVERFLOWS AND OUTGATES ovrfl cc h iniia cnainad a ha ravr h cavi, prvid ca ha h far id f h cavi, and prvid a ba hp jc h cain h di. th nbr and i f vrfl i a fncin f h fl dianc hrh h cavi hra n dianc i hav r vrfl and h rfac nih rqirn f h cain hra d rfac qai i hav r vrfl han a crcia nih. A id vrfl i a a prcn f the adjacent segment can be found in the table below:
tpica ovrfl si Thickness of Smt - . (mm)
Cavity Fill Time ovrfl s s prct f djct cvty smt - sc. hrdr Quty Sm Cd Sut ad - % Surface Finish - %
0.035 (0.90)
0.012 - 0.021
150
75
0.050 (1.30)
0.017 - 0.029
100
50
0.075 (1.80)
0.026 - 0.044
50
25
0.100 (2.50)
0.035 - 0.059
25
25
0.120 (3.20)
0.042 - 0.071
----
----
Note: th va hn ar pica va hich a chan fr pcic iain.
ovrfl ha cnnc vn hd b cad a h a prin f h n . If h vrfl bfr h n, hn bacin i ccr cain pr and pri. ma i b dran h a and vrfl, i i br hav an d vrfl han a f ar n fr prp f diribd fl ihin h cain. li rnnr, vrfl d n hippd, h nbr and pacn f vrfl hd b jdici. th a cnnc h cain h vrfl. th a f a h a ara hd b apprxia n haf h a ina ara inc h a prvid h paaa fr air cap hrh h vn. Fr ain h ini a hicn hd b .040 in. Fr ani and inc h ini hicn i .020 in fr cnvnina di cain. ovrfl ar nra cad n h jcr haf ih an jcr pin ndrnah h. oa i ina are normally located in the cover half. If pib h din f vrfl a ih vn hd b fr infcin a fl. th cncrn i p h n a ihin h di a h nd f h h. If h di d n hd h a, hn h pacin ha ccr a h a inan f i diinihd cain pr rfac nih and pri. Infcinc i crad hn h a i fr h vn frcin h a rn ihin h vrfl. GATING MANUAL
STEP 8 – DESIGN THE OVERFLOWS AND VENTS
ovrfl dinina daa an h cain nd b prvidd h ar r di dinr n h priinar di a. th fin i an xap f an vrfl.
VENTS Vn ar nia di cain. Vn h air f h di hrh h h. If hi doesn’t happen air and other gasses will be trapped within the cavity with the metal. The trapped gas will be in the form of smooth round bubbles that form gas porosity. These bubbles can be anhr, b i b cncnrad in h ara ha r h a r a h a pin idif. I i difc in di cain vn a h air. Hvr, hr i a bi dirnc in rida air and h ran cain qai bn n vn and prpr vn. If h di i dind ih infcin vn, vr i h air i nd a a . th di i flah, and f h flah will stick to the die causing inserts to be crushed unevenly into the holder block or the holder bc if i b crhd arnd h prir f h cavi inr cain cnin flah r “natural venting”. This all can be avoided by designing proper vents.
GATING MANUAL
STEP 8 – DESIGN THE OVERFLOWS AND VENTS
th b cain fr h vn ar h a pin . th iain prra b prdic h pin. A prra diribd b NADCA cad CaVi i d a d jb f prdicin h a cain. Air is compressible and reaches a terminal velocity in the vents no matter how much pressure is applied to the air. The air velocity in the vents assuming the terminal velocity is not reached is a function of the ingate velocity of the metal and the vent area. The air velocity in the vents is directly proportional to the ingate metal velocity and inversely proportional to the vent area. A a drin h vn ara i caca h incin a fl ra, and h vn ara h v f air ha can cap hrh h vn d ih xcdin a pd ha i 70% f h pd f nd a andard cndiin. t caca hi vn ara, h a fl ra (“Q”) i cacad r, and hn i i ad ha h air capin ha h a fl ra. If h axi ranab vci in h vn i ad b ab 70% f h pd f nd r 8000 in/c (200 /), hn h apprxia ini ara fr h vn can b fnd fr:
Minimum Vent Area = Q / 8000 Dpndin n h chic f variab, hi cacain apprxia h fra dvpd b J. F. waac:
aV = (0.00571)(V)/(T)(k) whr: AV
= h ini ara f h vn
V
= h a v f a in h , incdin rnnr and h v
t
= h cavi i
k
= h prcna f h vn ara rainin pn drin in
I d b ranab a h air in h h v i vd ndr pd cndiin, and i n a facr drin cavi in. If hi i h ca, cd V = cavi and rnnr v n, and a h prcna f vn rainin pn i ab 50%; hn the two formulas will be about the same. Another way to determine the vent area is to divide the ingate area by four or:
Vent Area = Ingate Area / 4 sinc h nra ran f ina vcii i han 2000 in/c, hi fra can a b d. th prb in dinin a vnin ih h prpr ara i ndin ra a n h di p a h vn in. I i aa a d ida hav a pan fr h vn bfr inin n h cavi inr i. si h i rdrd and hr in’ nh r ina h vn. thi i a bc cpicad ih id and hr far ha a i difc r ipib ina h prpr vnin. If h cain i niiv a pri, hn hi hd be a strong warning that there will be some gas porosity in the casting, or that freeze blocks or vac hd b cnidrd. on h hr hand, if h cain i n achind, and a pri is not an issue, then probably the designer should add as much venting as possible and accept the remaining porosity. The following is an illustration of a freeze block. The freeze block allows for a large vent area in a small die area. GATING MANUAL
STEP 8 – DESIGN THE OVERFLOWS AND VENTS
Vn nd b c in h cavi inr and pihd h ca a d n ic h. Vn hicn vari fr .005 .020. th air ha rianc flin hh vn ha ar .020 vr n ha ar hinnr. I i a d ida achin a a radi bn h vrfl and vn hp p h vn pn jcin. s vn ar dind ih p hp p h vn h di. Fr xap, h vn hicn ar a .020, and hn .015, and na .010. Hvr, ih ppd vn i i h a hicn ha h aphr ha cn fr vn ara. Vn nd rciv di b pra. Di b pra nhanc ra, ah fran f a h vn bfr h nx h, and c h vn di . si h prb f infcin cavi inr prad ccr. If h cavi inr prad is .002 inch or greater per die half, then the space between both holder blocks when the die is cd hd b fcin fr h air cap. Vn hd b dind fr infcinc. trn h a dn and pr frin. th bjciv i hav h a p dad bfr rachin h hdr bc. If a rach h hdr bc hn flah and inviab crhin i ccr. th vn nh rqird p h metal before reaching the holder block is a function of vent thickness - the thicker the vent the frhr h a i rav. exprinc and jdn ar h b id iain h vn nh ndd p h a. If h vn ar .020 inch hic, hn ab 4 inch f vn nh i b rqird p h a. Hvr, hi i cninn n a prar, di temperature, ingate velocity, amount of die lube spray on the vents, etc.
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GATING MANUAL
STEP 8 – DESIGN THE OVERFLOWS AND VENTS
A better system than vents to remove the air is to evacuate it during the shot with a vacuum . Vac rv h air and a r h rqird h prr a h a an h n and cranni f h cavi. Hvr, vac ha prb f i n a i anhr hin in h prc ha can rn ch a hn h vac vav ih a in h idd f a prdcin rn prdcin nihr vac r vnin. Fr ain din prp, i i ipran ha h prpr r b appid ndin h a pin ca h vac chann. man vac rnnr i h ina rnnr a vac i pd fr ip cain and fd ain vac rnnr adin b infcin ih rn and bind runners. th vac chann nd b ar nh ih rianc hand h airfl drin evacuation for the system to work properly. The time available for the vacuum system to work is less than 1 second. Although the pressure from the incoming metal will push some of the air out, the vacuum system should have evacuated most of the air before the metal arrives. The vacuum system suppliers are a good source for vacuum runner design information. th vac vav p vac hrh h nir h incdin fa h. wha rir h vav c i h a if rachin h vav. Hvr, h vav i prn faiin a metal eventually gets into the valve. An alternative to this approach is to pull the vacuum though a fr bc r fr bc. In hi ca, a h vci f arnd 10 in/c i d and h vac i h prir in in fa h. th vac v achivd ih hi hd will not be as good as with valves, but it is simpler and easier to maintain. The freeze block needs to be sprayed with air and die lube to prevent metal fragments from sticking and building up on the freeze block.
GATING MANUAL
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GATING MANUAL
9
STEP 9 – SIMULATION
The use of simulation is certain to become more popular as computers become more prf and h capabii f h iain far br. siain i a f engineering tool, and should be used to supplement the engineering work of gating and not to rpac i. In h dcribd ain prc in hi b hr ar a f apin ad b h dinr and a f hh ha i ndd fr an dind ain . siain i n a bi fr h chniq dcribd in hi b and hd b dn afr h ain din i cp Ida, iain hd b dn a ar a pib h r can h r can inflnc h par din. uin iain ha vra f and ipran bjciv ha can ai making the gating design better: 1.
wha d h iar a ab h fl parn? I h fl parn iiar n nviind in sp 2?
2.
whr ar h a ara ? Ar h a adjacn h ara?
3.
Ar hr ara f rappd a criica pri cnr? D h prpd din and pattern address them?
4.
D hrin pri ccr in ara criica pri cnr? D h prpd ina location and thickness address them?
5.
I hr rn fl ara hr rfac nih ar?
th a ara i h ai, and prbab h ipran f h facr cad b h r iain rn. thr a b vra pc f pib rappd a hr h a ha n cap pah, and i rrndd b iqid a a h nd f . th cain cd hav a pri and prhap pr .. A prdc f h NADCA rarch r i a prra cad CaVi, hich i dind ca h a pin qic. th prra can rn in in a ppd h hr ndd b f bn crcia iain far. I a can b rn b ann, and d n need a trained simulation operator to use it. th dinr hd drin if h a pin ar a a cain hr vrfl and vn can b rcad r addd. If h ar in ara hr rfac nih r pri ar, hn pib fl parn ih rvid ina cain can b chand and anhr iain dn. If hr ar ara criica rfac nih rqirn, hn h ara hd b chcd fr h fl cndiin, fr a vr ini an f ir, and paricar fr an indicain f ar a fl ixin ih a a fl n h rfac.
GATING MANUAL
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STEP 9 – SIMULATION
If hr i an ara f cncrn ab a pri, hn h r hd chc fr ir r rappd a pc in hi ara. thr hd b h a fl hrh hi ara, and h pc hd b in hr cain. If h far i capab, hi hd incd xainin h inrna fl inid h cain. th fl iain a nd b chand and rpad vra i fr dirn ain and process conditions to get the optimum gating situation. This will be similar to the same ria and rrr hd ha d b dn n h di cain achin. Hvr, i i j a cheaper and faster on the computer. The information learned from simulation can be valuable, but the user needs make sure the results are interpreted properly by someone familiar with die casting and not just familiar with simulation. If hr i cncrn ab hrin pri, hn an iniia hra anai hd b rn. th thermal analysis will be needed for oil and water cooling channel placement and can predict the cd ara and h h ara ha a ac rfac nih r hrin pri. m a hi i can n prdic h r f appin innid prr drin idicain a h r dind fr hr cain prc n prr cain. th r hd hav xprinc in die casting to interpret the results and be somewhat cautious with the simulator’s results. sinc iar i prdic h cd and h h cain, hi infrain can b civ in pacin ar r h i in. Di b pra a rv ha b n a can accn fr h c f h pra. man inrain f h hra iain ar dn hr h cin channels are moved, resized, and the coolant changed in order to optimize the design. onc h ain and h hain/cin ar piid, hn h di din can b naid and ivn h di dinr f ar cnrcin can ar. Cpr ar in far and far i in chapr and br. th da ar cin where simulation will be the standard method of verifying and optimizing gating designs.
REFERENCES 1.
e.A. Hran, J. F. waac, “Cppr A Prr Di Cain”, Inrnaina Cppr Rarch Aciain, 1975
2.
e. A. Hran, “gain Di Cain Di”, sci f Di Cain eninr, 1979
3.
e. A. Hran, “Di Cain Di, Dinin”, sci f Di Cain eninr, 1979
4.
J. A. waac, “Pracica Appicain and h R f ma F and gain Rarch”, , 1965
5.
R Van Rn ,“gain Din”, NADCA, 1996
6.
w. wainn, “svn sp Qai gain Din”, NADCA, 2001
7.
Dr Cc, “Fan and tann ga Fd Din s” , Arican Di Cain Ini, 1987
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GATING MANUAL
STEP 9 – SIMULATION
GATING MANUAL
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