High-pressure fuel supply pump having electromagnetically-driven intake valve

摘要

Responsiveness is improved in valve opening and valve closing of an electromagnetically driven intake valve unit in which a valve is provided on a pressurizing chamber side of a valve seat. The valve includes an annular abutting surface that abuts the valve seat to shut off a fuel intake passage and a bottomed cylindrical part provided at an inner peripheral part of the annular abutting surface. The bottomed cylindrical part is inserted into a fuel introduction hole formed in the valve housing inside the valve seat, and the outer surface of an end part of the bottomed cylindrical part is exposed to fuel in a low pressure fuel chamber provided upstream of the fuel introduction hole.

主权项

1. A high-pressure fuel supply pump comprising:
a pump housing in which a pressurizing chamber is provided; a piston plunger supported by the pump housing, permitting the piston plunger to repetitively perform a reciprocating motion within the pressurizing chamber to suck fluid into the pressurizing chamber, pressurize the fluid therein, and discharge the fluid out of the pressurizing chamber; an electromagnetically-driven intake valve unit including an intake valve and a valve seat; an electromagnetic driving mechanism for controlling an opening or closing timing for the electromagnetically-driven intake valve unit; and a low pressure chamber communicated with an intake side of the high-pressure fuel supply pump; wherein the intake valve includes an abutting surface that abuts the valve seat to shut off a fuel intake passage and a cylindrical side wall exposed to the low pressure chamber and defining a volume closed off at one end having an end wall with an external surface that is located in the low pressure chamber.