摘要 |
A pump may have a first chamber and a solenoid coil to control movement of a first valve member. A second chamber may have a second valve member to control fluid moving into a third chamber. A first fluid passageway may link the first and second chambers, a second passageway may link second and third chambers and a third passageway may link third and fourth chambers. After pressurizing the third chamber causing fluid to flow into and leave a fourth chamber, the third chamber depressurizes due to downward movement of a plunger. Upon depressurization with a solenoid coil energized, second valve member floats and then moves against a valve seat. While the second valve member is moving toward the valve seat, the solenoid coil is de-energized causing the first valve member to move and strike the second valve member when the second valve member is moving at maximum velocity. |