Common rail fuel injection control apparatus using a variable discharge high pressure pump and the variable discharge rate high-pressure pump

摘要

PROBLEM TO BE SOLVED: To provide compatibleness of high accuracy of flow control with miniaturization of the device and reduction of the cost, for a variable delivery- amount high-pressure pump. ;SOLUTION: Low pressure fluid is introduced from a feed flow passage 11 to a pressure chamber 23 expanded or shrunk with reciprocating movement of a plunger 21, is pressurized, and is force-fed to a high-pressure flow passage 33. A variable throttle valve 5 is provided between the pressure chamber 23 and the feed flow passage 11. A check valve 4 is provided between the variable throttle valve 5 and the pressure chamber 23 so as to flow fluid only in the direction of the pressure chamber 23. A control means P3 for controlling the opening of the variable throttle valve 5 adjusts the opening during non-force feed and time ratio of the opening period to the closing period, increases adjusting accuracy of suction amount to the pressure chamber 23 even when opening adjusting cannot be enough accurately performed in relation to varying amount of required force feed amount, and allows use of a small and inexpensive variable throttle valve 5.;COPYRIGHT: (C)1999,JPO