JPS61118939U - - Google Patents

Description

[Brief explanation of the drawing]

FIG. 1 is an overall sectional view showing an example of a fuel injection pump to which the present invention is applied. FIG. 2 is an enlarged cross-sectional view of the main part of FIG. 1, showing an embodiment when used as an auxiliary chamber type. FIG. 3 is an enlarged sectional view of a main part corresponding to FIG. 2, showing an embodiment when used as a direct injection type. FIG. 4 is a diagram showing the required characteristics for the sub-chamber type. FIG. 5 is a diagram showing required characteristics in a direct injection type. A: Fuel injection pump, B: Fuel storage chamber, 1:
Housing, 17: Speed timer mechanism, 18:
timer piston, 31: cylinder, 32: inflow path, 33: communication path, 34: return spring, 3
5: Relief passage, 36, 37: Communication port.

Claims (1)

[Claims for Utility Model Registration] A timer piston that is slidably inserted into a cylinder formed in a housing, and a hydraulic pressure that is defined on one end surface of the timer piston and increases in accordance with the pump rotation speed is supplied. In a fuel injection pump having a speed timer mechanism, the speed timer mechanism includes a high pressure chamber in which the timer piston is moved toward the high pressure chamber, and a return spring that biases the timer piston toward the high pressure chamber. A relief passage for relieving the high pressure chamber to the low pressure side is formed, and the timer piston functions as a valve body for communicating and blocking the high pressure chamber with the low pressure side via the relief passage. A fuel injection pump characterized in that the high pressure chamber is communicated with the low pressure side via the relief passage only when the timer piston is in a predetermined movement range.