VALVE OPENING PRESSURE MEASURING METHOD AND DEVICE FOR TWO STAGE VALVE OPENING PRESSURE TYPE FUEL INJECTION VALVE

摘要

PURPOSE:To measure the valve opening pressure upon a main injection at a position where the needle valve therefor is lifted up easily by a method wherein a gauge is provided in the two stage valve opening presure type fuel injection valve. CONSTITUTION:A fuel injection valve 21, regulated in the valve opening pressure upon the initial injection thereof beforehand, is mounted on the adaptor thereof and the injection pipe 46 of a nozzle tester is connected to the fuel passage of the fuel injection valve. A contacting rod 32 connected to a dial gauge is abutted against the surface of the seat of a spring for a second push rod 11. A regulating screw member 10 is rotated to make a gap DELTAl between the upper end surface of a first push rod 5 and the tip end of the second push rod 11 zero. At this position, the dial gauge is also adjusted to zero. Subsequently, the regulating screw 10 is rotated into the reverse direction to adjust it to DELTAl, thereafter, the regulating screw 10 is locked. The position of the needle valve which is lifted up is determined by these operations, subsequently, the pressurized oil of the nozzle tester 40 is supplied to a pressurizing space 2b, a pressure when the indicator of the dial gauge 31 is begun to move is read by a pressure gauge 44 and the pressure is regulated so that it will become to the predetermined valve opening pressure upon the main injection.