US 5,957,674 AGranted

Variable-discharge high pressure pump

AssigneeMitsubishi Denki Kabushiki Kaisha

InventorsKeisaku Zenmei, Nobuyuki Kanda, Keiichi Konishi

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Abstract

A variable-discharge high pressure pump capable of facilitating the manufacturing and providing sufficient lubrication. The pump comprises a cam shaft provided with a cam surface by which a tappet displaces in accordance with the cam surface, a plunger connected to the tappet to reciprocate in accordance with the reciprocation of the tappet and accommodated in a cylindrical cylinder. Also included are a cylinder head having a contact surface brought into contact with one end surface of the cylinder. The cylinder head has a small-diameter recess portion made in the contact surface to be coupled to the cylinder and constitutes a pump chamber in conjunction with a head portion of the plunger. Further, the cylinder head holds a fuel introduction device for introducing external fuel into a fuel supply passage communicating with the pump chamber, a solenoid valve for opening and closing the fuel supply passage in accordance with an energization state thereto, and a fuel discharging device for discharging fuel compressed in the pump chamber. The cylinder is placed through a fixing device into contact with the cylinder head.

Claims3

Dependent claims

A variable-discharge high pressure pump comprising:

a cam shaft driven to rotate and provided with a cam surface therearound;
a tappet pressed against said cam surface to displace in accordance with said cam surface;
a housing for holding said tappet to allow it to reciprocate;
a pole-like plunger having no stop groove and connected to said tappet to reciprocate therewith;
a cylindrical cylinder accommodating said plunger to allow it to reciprocate;
a cylinder head having a contact surface brought and placed into contact with one end surface of said cylinder and including a small-diameter recess portion made in said contact surface to be coupled to said cylinder and to constitute a pump chamber in conjunction with a head portion of said plunger;
fuel introduction means placed on said cylinder head to introduce external fuel into a fuel supply passage communicating with said pump chamber;
a solenoid valve installed on said cylinder head to open and close said fuel supply passage in accordance with an energization state thereto;
fuel discharging means fitted on said cylinder head to discharge fuel compressed in said pump chamber;
and
fixing means for bringing and placing said cylinder into contact with said cylinder head.

8 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/795,243Filed 10 Feb 1997
Priority: JP 8-1713361 Jul 1996
Granted: 28 Sep 1999
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

F02M 59/366
By variably-timed valves controlling fuel passages to pumping elements or overflow passages: valves being actuated electrically
F02M 59/44
Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00 , e.g. rotary cylinder-block type of pumps:…
F02M 63/0225
Fuel-injection apparatus having several injectors fed by a common pumping element, or having several pumping elements feeding a common injector;…:…
F04B 49/243
Bypassing: by keeping open the inlet valve