PRESSURE OPERATED MECHANICAL FLOW CONTROL VALVE FOR GASOLINE DIRECT INJECTION PUMP

摘要

A flow control valve (15) for a direct injection pump (10), the pump having an inlet end (12), an inlet valve (26), a compression chamber (48), a pump piston (14) and an outlet (13). The valve (15) has a housing (16) and a non-electrically operated control plunger (22) movable within the housing. The control plunger engages with and disengages from the inlet valve to control opening and closing of the inlet valve. A spring (28) biases the control plunger away from the inlet valve. The pump and the housing define a port structure (38, 44) fluidly connecting the outlet with a volume (42) that communicates with the control plunger such that when fluid pressure at the outlet is greater than a certain value, the fluid pressure in the volume alone causes the control plunger to move against the spring and engage the inlet valve to hold the inlet valve in an open position.