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

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 in a way 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 housing member placed around an outer peripheral side of the intake valve;
• 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 provided radially inwardly of the abutting surface;
• wherein an outer surface of the cylindrical side wall is positioned upstream of the pressurizing chamber relative to the valve seat, and the abutting surface is positioned at a pressurizing chamber side relative to the valve seat when the intake valve is closed;
• and
• wherein a gap between the outer surface of the cylindrical side wall and an inner surface of the housing member is larger than another gap between the abutting surface of the valve and the valve seat in an axial direction.

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 by an end wall having an external surface that is located in the low pressure chamber;
• wherein a through hole has a constant diameter between the inlet and the end part of the pressurizing chamber side, and the end part, on the side of the pressurizing chamber, of the through hole forms a fuel inlet opening of the pressurizing chamber;
• and
• wherein an outer peripheral surface of a valve housing is press-fitted to an inner peripheral surface of the through hole.