Patent ID: 8052404
Filing Date: 2011-11-08
Classification: F02M,F04B

Abstract:
1. A high pressure pump configured to draw fluid from a fluid inlet into an inlet chamber and configured to pump fluid in a compression chamber drawn from the inlet chamber, the high pressure pump comprising: a plunger movable to pressurize fluid drawn from the inlet chamber into the compression chamber; a cylinder in which the plunger is substantially axially movable; a control valve configured to control communication between the inlet chamber with the compression chamber for metering discharged fluid; a fuel chamber configured to change in volume according to movement of the plunger; a discharge passage configured to communicate the inlet chamber with the fuel chamber; a discharge valve configured to discharge fuel pressurized by using the plunger; wherein when the plunger moves downward to draw fluid from the inlet chamber to the compression chamber, the fluid chamber decreases in volume thereby to cause the inlet chamber to draw fluid from the fluid chamber, when the plunger moves upward to return fluid from the compression chamber to the inlet chamber, the fluid chamber increases in volume thereby to cause the inlet chamber to discharge a part of returned fluid to the fluid chamber through the discharge passage, the control valve includes a valve member, a valve seat, a first spring, a coil, and a shaft, the valve member is configured to be lifted from the valve seat and seated on the valve seat for controlling communication between the inlet chamber with the compression chamber, the first spring is configured to apply first biasing force to the valve member in a direction to seat the valve member on the valve seat, the shaft is applied with magnetic force to be attracted when the coil is energized, when the plunger begins to move upward from a bottom dead center toward a top dead center, the coil is being de-energized to lift the valve member, which is in contact with the shaft, from the valve seat to communicate the inlet chamber with the compression chamber, and in a course of movement of the plunger toward the top dead center, the coil is energized to apply magnetic force in addition to the first biasing force to attract the shaft thereby to seat the valve member on the valve seat to block the inlet chamber from the compression chamber.