INJECTION TIMING CONTROLLING DEVICE OF DISTRIBUTING TYPE FUEL INJECTION PUMP

PURPOSE:To freely control the injection timing characteristic and consequently improve the starting characteristic by a structure wherein springs are provided in the chambers formed at both sides of the timer piston of the fuel injection pump and a solenoid valve to control the ratio of the fuel pressure in one chamber to that in the other chamber. CONSTITUTION:The timer piston 22 is installed in a cylinder 21 integrally formed with a fuel injection pump housing. The springs 25 and 26 are housed in the chambers 23 and 24 formed at both sides of the timer piston 22 respectively. A two position three way solenoid valve 36 controls the ratio of the fuel flow rate in a fuel passage 34 to that in a fuel passage 35. At starting, the solenoid valve 36 is controlled so that fuel is flowed from a fuel leading-in passage 29 through a peripheral groove 30 and the solenoid valve 36 into the fuel passage 34 and then lead to the chamber 23. As a result, the timer piston 22 is moved in the direction, toward which pressure is applied, resulting in enabling to advance the injection start timing.