Engine Control System 1A-7 Structure and Operation 1. Higher pressure of injection fuel An inner cam with a cam ring and radial plunger are used to increase the pressure of the injection fuel. The cam ring is supported on the pump body side and provided with projections (cams) on the internal periphery. Four plungers are provided at an interval of 90°, incorporated in the rotor integrated with the drive shaft, and in contact with the internal periphery of the cam ring in the radial direction through the roller.
When the drive shaft rotates, the plunger moves on the cam ring internal surface through the rolling of the roller, pushed out in the shaft center direction with the inner cam and compresses the fuel. Four plungers operate simultaneously. This enables higher pressure (75 ~ 130 MPa) and high rigidity is obtained since the load becomes relative load in the radial direction. Plunger diameter is ш7.5mm and the cam lift is 2.5mm. 3. Fuel injection amount control Fuel injection amount is adjusted by opening or closing the fuel high pressure circuit with the high response SPV (spill control valve). EDU (engine driver unit; a high voltage driver) is employed to drive the SPV at a high speed.
EDU can drive the SPV of high fuel pressure at a high speed by the high voltage and high speed energizing system. 4. Pump ROM In order to compensate the variation of correlation between the fuel pump and engine, variation of the injection amount inherent to the injection pump is corrected. 5. Air bleeding of injection pump a. Pumping until the pump is hard to operate. b. Start the engine. If not started, repeat pumping. c. After the engine is started, keep the engine speed at 1000 to 1500rpm for about 10 seconds. d. Stop the engine. e. Check for fuel leakage. 1 Legend 1. Cam ring 2. Rotor 3. Timer piston 4. Roller 5. Plunger Legend 1. Priming pump 2. Plug 3. Sensor 4. Cartridge 2.
Injection timing control Injection timing is adjusted by shifting the cam ring phase with the fuel pressure applied to the back of the timer piston. The fuel pressure applied to the timer piston is controlled with the ECM (engine control module) through the timing control valve. 1 5 2 4 3 LNW21ASH000401 4 3 2 LNW21ASH000501