Common Rail System
BENEFIT
DENSO’s second-generation 1,800-bar common rail for cleaner and quieter diesel engine
Innovative technologies greatly reduce diesel’s impact on the environment. 1. Up to 1,800-bar injection pressure 2. Up to five times multiple injection per cylinder
The features greatly reduce visible smoke, particulate matter and NOx while minimizing engine noise.
Common Rail System
BENEFIT
DENSO’s second-generation 1,800-bar common rail for cleaner and quieter diesel engine
Innovative technologies greatly reduce diesel’s impact on the environment. 1. Up to 1,800-bar injection pressure 2. Up to five times multiple injection per cylinder
Cleaning up diesel exhaust gas
Minimizing engine noise
Diesel fuel is injected into the combustion chamber at ultra high pressures of up to 1,800 bar to ensure more complete combustion for cleaner exhaust gas.
Highly precise multiple injection creates combustion to reduce NOx emission and combustion noise.
Common Rail System
BENEFIT
DENSO’s second-generation 1,800-bar common rail for cleaner and quieter diesel engine
Innovative technologies greatly reduce diesel’s impact on the environment. 1. Up to 1,800-bar injection pressure 2. Up to five times multiple injection per cylinder
Single Injection (Conventional)
Pilot Injection (First-Generation Common Rail)
Multiple Injection (Five Times)
Common Rail System
BENEFIT
DENSO’s second-generation 1,800-bar common rail for cleaner and quieter diesel engine
Single Injection Single Injection Pilot Injection Multiple Injection
time
Condition ・Passenger Car ・Engine: 2L / 4cyl ・Turbo Direct Injection ・Noise at Idling
Common Rail System
BENEFIT
DENSO’s second-generation 1,800-bar common rail for cleaner and quieter diesel engine
Pilot Injection (Two Times) Single Injection -3ｄB
Pilot Injection Multiple Injection
time
Condition ・Passenger Car ・Engine: 2L / 4cyl ・Turbo Direct Injection ・Noise at Idling
Common Rail System
BENEFIT
DENSO’s second-generation 1,800-bar common rail for cleaner and quieter diesel engine
Multiple Injection (Five Times) Single Injection Pilot Injection -4ｄB
time
Condition ・Passenger Car ・Engine: 2L / 4cyl ・Turbo Direct Injection ・Noise at Idling
Multiple Injection
Common Rail System
TECHNOLOGY
DENSO’s second-generation 1,800-bar common rail for cleaner and quieter diesel engine TECHNOLOGY Co mmo n Rail Sy stem 1,800 bar injection pressure is equivalent to the water pressure of a depth of 18,000 meters deeper than the Mariana Trench, the world’s deepest ocean bottom. High response injectors by electronic control feature the highly accurate multiple injections (five times). As a result, particulate matter and NOx are markedly reduced, w hile improvements in fuel efficiency and torque are achieved. Plus, engine noise and vibration are also reduced. High High pressure pressure capacity capacity technology technology Magnetic Magneticvalve valve technology technology
ECU ECU technology technology Sensor Sensor technology technology
Diesel Engine Management Sy stem EGR V alve
DPF
Common Common rail rail technology technology
Diesel engines have the advantages of good fuel efficiency and low CO2 emissions. Therefo re, DENSO developed a diesel engine management system to further clean up emissions w hile improving fuel efficiency. This system is a product of various forms of advanced technology. Among them is the common rail system employed in the fuel injection.
Common Rail System
TECHNOLOGY
DENSO’s second-generation 1,800-bar common rail for cleaner and quieter diesel engine TECHNOLOGY 1 Supply Pump The first-generation supply pump could generate pressures of up to 1,450 bar, w hich represented the mechanical limits of the inne r cam design. However, to achieve pressures above this, DENSO developed revolutionary new coating and machining technologies, and by the secondgeneration design, changed to an outer cam design in the supply pump to achieve pressures up to 1,800.
Supply Pump Feed Pump Cam Ring
Housing Cam Shaft
Suction Control Valve Eccentric Cam
Connecting Pipe
TECHNOLOGY 2 Co mmon Rail
In order to w ithstand 1,800-bar pressure the rail must be w ithout any clearance or machining error. In response, DENSO developed a special material that contains few er compounds, w hile exhibiting high purity and high hardness properties to enable ultra high-precision machining. Thus, it is possible to create engine components that can w ithstand pressures up to 1,800 bar for use in the common rail system.
Plunger
To Rail
Common Rail From Supply Pump To Injector
Pressure Sensor
To Injector
Pressure Limiter
Common Rail System
TECHNOLOGY
DENSO’s second-generation 1,800-bar common rail for cleaner and quieter diesel engine TECHNOLOGY 3 Solenoid Injector Compared w ith its first-generation injector (1,450 bar, tw o-times injection) DENSO developed higherresponse solenoid actuator and high-pressure Solenoid Valve injector design. The second-generation injector is able to inject up to 1,800 bar pressure and multiple injection, w ith timing intervals of 4/10,000 seconds during w hich a maximum of five injections takes place. As a result, exhaust gas is cleaner w hile noise is minimized. In injection control systems, advanced piezoelectric components are employed because of their high speed operation capability. But DENSO was successful in developing conventional solenoids that operate in 0.2 millisecond units.
Command Piston
Injector (up to 5 times injection a cylinder) 160M Pa Qpilot :2mm3/st , Qpre: 2mm3/st , Qmain:80 mm3/st , Qaft er:5mm3/st , Qpost :2mm3/st ,
From Rail (high pressure) Drive Current (A) time
Valve Lift (μm) time 1.0ms
Nozz le
Injection Rate (mm3/ms) time
