Patent ID: 7604462

Claim:
A method for introducing fuel for a high pressure pump, which is configured to draw fuel from a fuel inlet into an inlet chamber and pressurize and discharge the fuel drawn from the inlet chamber into a compression chamber, the high pressure pump comprising: a plunger that is movable to draw fuel from the inlet chamber into the compression chamber and pressurize the fuel; a cylinder that movably supports the plunger therein; a control valve that is configured to control communication between the inlet chamber and the compression chamber to control an amount of discharged fuel; a fuel chamber that communicates with the inlet chamber through a discharge passage and configured to change in volume in response to movement of the plunger; and a discharge valve that discharges fuel, which is pressurized by the plunger; the method comprising: introducing fuel from the fuel chamber into the inlet chamber and drawing the fuel from the inlet chamber into the compression chamber in response to reduction in volume of the fuel chamber when the plunger downwardly moves in an intake stroke; returning the fuel from the compression chamber into the inlet chamber and partly discharging the fuel, which is returned into the inlet chamber, into the fuel chamber through the discharge passage in response to increase in volume of the fuel chamber when the plunger moves upwardly in a return stroke; and blocking the inlet chamber from the compression chamber using the control valve midway through the return stroke to compress the fuel in the compression chamber in response to upward movement of the plunger in a compression stroke.