Broaching is a process of metal cutting. It is about operation in one pass. The tool is broaches and has several cutting edges. In next presentation w...
Abstract Broaching is a rocess of metal cutting! "t is about oeration in one ass! #he tool is broaches and has several cutting edges! "n ne$t resentation %ill be e$lain tye of tools& rocedures of treatment& methods of treatment and others! #he machine used for this treatments is broaching machine and the thesis rovides a systematic model of vertical broaching machines!
Table of contents '! "ntroduction!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !( )! Proccessing of broaching!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!* 2.1 Types of threading............................................................................................................................. 5 2.2 Cutting sheme....................................................................................................................................6 (! +achines and tools in rocessing of broaching!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!, *! +odeling elements of electro-mechanical broaching machine!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!'' ! .onclusion!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! '* /! 0iterature!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! '
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1. Introduction Broaching oeration reresents metal rocessing& %here the rocessing is done in one ass! #he tool is broaches and designed to linearly asses erendicular to the %or1iece in the direction of the a$is of the tool! #he relative movement of the tool through the %or1iece rovides broaching machines 2Broaching3! #he tool can be ushed 2%hich is less common method of treatment3& or dra%n through the %or1iece! Broaching can be internal 2%hen the tool handles the inner surface of the %or1iece3 or e$ternal 2%hen the tool rocesses the outer surface of the %or1iece3!
#echnology-through rocessing is e$lained in the second chater describes the 1inematicsthrough rocessing %here %e can see the osition of the tool in the treatment of internal and e$ternal broaching& broaching tyes& methods and tyes of broaching and cutting scheme!
#he third chater describes the machines for broaching of some manufacturers and their main characteristics& the tools in the rocessing of broaching and their basic structural elements! 4lso the choice of form sace bet%een teeth& chi brea1er and handles broaches 2for internal and e$ternal broaching3!
Based on the above characteristics and broaching broaches the fourth chater %as used for modeling the electro-mechanical arts Broaching& or gear and rac1& chuc1 tools& ole mount and an electric motor& in the rogram .4#"4 56)'! Before ten or more years %ith the Faculty of +echanical Engineering& rofessors decided to construct broaching machine& %hose made almost all the elements of the machine and it is not finished yet! Broaching is modeled according to the already e$isting elements!
2. Proccessing of broaching 3
#he rocessing of broaching characteri7ed by high roductivity in terms of high series and mass roduction and high roductivity of machining rocesses! 8esite the simle 1inematics rocessing this treatment rocess is one of the most comle$ rocesses of metal rocessing! #he reasons are in the fact that the rocessing of broaching usually finishing oeration and that rocessing is erformed at very high values of loads of tools and machines! "n this connection& the entire machining system 2tools& machines& comression fittings3 should be characteri7ed by high levels of static and dynamic stability! 8ue to the high cost of tools& broaching alies only in standard& high series and mass roduction 29edić& ) ;3!
"n most cases& rocessing is erformed by assing the linear movement tools! #he %or1iece do not erform suort the movement& because suort movement actually does not e$ist& e$cet in some secial cases 2helical broaches3! Suort motion in some %ay is incororated in the tool itself! Processing is carried out by dra%ing a tool& rarely reression& along the a$is of the %or1iece! "n Figure )!' are resented rocessing scheme for internal and e$ternal broaching %ith numbered ositions! "n osition ' is broaches& osition ) guides& (! %or1 des1& *! the %or1iece 29edić& );3!
Figure 2.1 Scheme of processing by broaching a) internal, b) eternal !"edi#, 2$$%)
2.1 Types of threading
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#here are three tyes of threading: •
Progressive broaching
•
6otary broaching
•
+ethod of rocessing staming
"n rogressive broaching& broaches have cutting edges& they have the same distance from each other but they have different %idths 2htt:<<%%%!ignou!ac!in
Internal broaches
Workpice
Figure 2.2 Scheme of progressi&e broaching
6otary broaching is used to remove large amounts of material in the holes that are forged or cast %hich is not desirable rogressive broaching! #he teeth in these broaches are arranged in e$tent %hen turning the cuts filings off a iece and allo% filings evacuation! #his is recommended for the roduction of s=uare or he$agonal oenings of round 2 htt:<<%%%!ignou!ac!in
Workpiece
Rotary broaches 5
Figure 2.' Scheme of rotary broaching
4 method of rocessing staming is used for ma1ing olished and final surface on the metal iece! #his is used for finishing holes! #he teeth of this tool are rounded and not cutting& or comress and rub the surface of the metal 2htt:<<%%%!ignou!ac!in
Stamping broaches
Figure 2.( Scheme of processing tools for stamping
2.2 Cutting sheme .utting scheme to broaching means cutting adoted the order 2remove3 bonus for the entire treatment! #here are a number of different cutting schemes& %hich mainly deends on the shae and dimensions of the rofile of the %or1iece! "t is very imortant that you ma1e at least a rough otimi7ation of selection schemes cutting 2#adić& )'3!
#his means integrally revie% and analy7e selected scheme and cutting effects achieved in terms of: >
the necessary traction force of machines
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load broaches 2critical tensile stresses at broaches for internal broaching3
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re=uired length broach or number broaches included
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the value of cutting deth er tooth 2stes er tooth3
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the number of teeth broaches
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achieving the re=uired geometric accuracy and high surface =uality and others!
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"n Figure )! sho%s some of the ossible schemes of cutting!
Figure 2.5 Cutting scheme to broaching !Tadi#, 2$15)
3. Machines and tools in processing of broaching 5ertical broaching for internal broaching 2Figure (!'3 are the most common tye of machine constructions for internal broaching! #he %or1iece 2;3 is laced on a des1 machine 2)3& and the tool is in the initial stage of rocessing& before rocessing& laced in the bac1 of a leading art of the machine 2'3! #he tool& leading through the last art leads into the oerating osition %hen the front receiving ortion 2*3 accetance tool! #han1s to the oerating system machine 2electric motor & the transmission system / and the mechanism for converting rotary to linear motion3 leading the front art of the machine receives the necessary movement and traction machines&
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necessary for the reali7ation of machining rocesses! Uon comletion of the cutting rocess 2reaching lo%er oints travel tools3& the %or1iece is removed from the %or1 table and the tool returns to the starting osition 2#adić& )'3!
Figure '.1 Scheme of pneumatic &ertical roaching for internal broaching !Tadi#, 2$15)
?ori7ontal broaching machine for internal broaching 2Figure (!)3 are %or1ing on a similar rincile& e$cet that the movement of the tool 2)3 in the hori7ontal direction and %hat is necessary to ensure an aroriate system for receiving and claming the %or1iece 2'3! ?ori7ontal broaching machines rovide the ossibility of continuous oeration stationary tool if the %or1iece laced on the rotary table or conveyor belt 2#adić& )'3!
Figure '.2 Scheme of hori*ontal broaching machine for internal broaching !Tadi#, 2$15)
Basic structural elements of broaches defined deending on its urose! "n broaches for internal threading 2cylindrical broaches figure (!(3 basic elements are as follo%s: '! handle broaches )! nec1 broaches
(! the transition cone *! the front art of the leading ! cutting art /! calibrated art ;! the last leading art ,! the receiving art
Figure '.' The basic elements of cylindrical broaches !Tadi#, 2$15)
?andle broaches used for accetance by the eternal system broaching machine! #he front art of the leading broaches for guidance tools through re-treated aroriately oening or rofile that formed the revious broaches 2%hen dealing %ith a set of broaches3! @n the cutting art of broaching tools are formed cutting segments 2teeth3 that after cutting rofile scheme or in the aroriate sections 2rogressive scheme3 cut a comlete sulement for treatment of s%iing! @n the art of the calibrated tools are calibrated formed teeth! #he length of this art of the tool deends on the number of calibrated teeth and their stes! #he last art of the leading tools used for leading tools already formed by the rofile! #he receiving art of the tool is used for acceting tools by the receiving mechanism of the machine! "n Figure (!* sho%s some of the ossible constructive solutions of sace bet%een the teeth 2#adić& )'3!
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Figure '.( Some of the possible constructi&e solutions bet+een the teeth !Tadi#, 2$15)
4. Modeling elements of electromechanical broaching machine +ain urose of the broaching machine is obtaining the desired shae of the %or1iece by removing e$cess material& it must receive ade=uate energy to be converted into mechanical %or1! 4t a ne% machine for this urose almost e$clusively used electricity& and the drive is reali7ed by electric motors& using electricity from the grid converted into mechanical 2Aahar& ';3!
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Figure (.1 Threephase asynchronous motor +ith shortcircuited rotor
For further transfer of rotary motion electro-motors can be used gear grou& grou transfer belts& transfer chain grous and others! @r a combination of the grou gear and transfer belts& as it is used in a given broaching! #he theme of the %or1 does not re=uire a more detailed study of the driveline grou of gears at broaching& so it %ill not go further on the subject! 8ue to the high o%er re=uired e=uiment attached to the three belt 2belt3 from the o%ertrain to the movement of the drive 2gear - gear lath3 machines& to revent itCs raid shooting! "n Figure *!) sho%s the transfer model ! #he %idth of the belt is * mm& a length of the stra around '/ mm!
Figure (.2 gear housing and belt dri&e #he desired movement is linear for broaching! #his can be achieved in several %ays! For e$amle& a curve mechanism %hich is very good but it re=uires a large construction machine& then the %orm gear %hich is also very good& or using the gear air 2gear - gear lath3 that does not re=uire a comle$ structure in Figure *!(! 5ertical broaching machine concerned the benefits of gear and gear-lath! Dear has a diameter of *(mm and a %idth of * mm %ith a modulus of )!/!
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Dear- lath has a length of ;) mm& a %idth of * mm and a modulus of teeth is also )!/! or1ing stro1e is about ; mm!
Figure (.' Timing couple @n the gear-lath is attached to the head for acceting and broaching tools 2broaches3 Figure *!*!
Figure (.( The board "n the Figure *! are sho%n recetion head and slider!
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Figure (.5 -eception head and slider "n the Figure *!/ are sho%n vertical electro-mechanical broaching machine!
Broaching is one of the machining oerations& %hich is used as a tool broaches! #he rocess of cutting has the one-movement& rectilinear! #his rocessing is called highly roductive because the roduction of tools are e$ensive! Broaching can be for the inner surface& as %ell as for the outer surface of the %or1iece! 8eending on the tyes of broaching cutting is classified as a rogressive cut& rotary cut and embossing surface!
Broaching machines is rimarily divided into hori7ontal and vertical& indoor and outdoor roducts& and also on the tye of roulsion& %hether they are hydraulic& electrical& or other broaching! #hey are characteri7ed by large mass& high traction force& high recision machining and long roduction runs! #here are various tyes of metal rocessing machines by broaching! #hey may be machines for broaching hard materials& machines in %hich the %or1iece moves a stationary tool& small si7e machines& machines for siral-through rocessing& machines %here the %or1iece is heated& machines for continuous rocessing %here there is a stri for %or1 ieces& machine %hich can be carried out by treatment %ith t%o tools simultaneously 28ual ram3 etc!
Broaching tool selected based on the re=uired length of threading& the mechanical roerties of the %or1iece and geometric accuracy and the re=uired =uality of rocessing! #he structural elements of tools includes front and rear receiving art& the cutting teeth and sace bet%een the teeth! Bonfire filings %ere no less imortant! +aterial of broaches should be higher hardness deending on the tye of %or1iece!
#he fourth chater describes %hat is the rimary tas1 machines& aro$imate geometry and function of each element! "n addition to the e$isting basic elements are modeled elements 2ole slider and guides3 to facilitate the %or1 tools for returning to the starting osition& made some minor modifications to the receiving head to be coa$ially %ith the oening in the mounting brac1et! #he board of the toothed air and the ulley has also been modified& it is ossible to easily set the belt on the ulley!!
