High-pressure fuel supply pump comprising electromagnetic drive-type suction valve

Abstract

Provided is a high-pressure fuel supply pump comprising a normal-close, electromagnetic drive-type suction valve mechanism, adaptable to increased capacity and having little noise generation. The high-pressure fuel supply pump comprises a valve member having a sheet surface that comes in contact with a suction valve sheet, and a plunger rod positioned on the sheet surface-side of the valve member, and which operates the valve member by magnetic attraction force; and is provided with a protector arranged facing, across a gap, the opposite side surface to the sheet surface of the valve member, when the plunger rod is at full stroke in the valve opening direction for the valve member, and an anchor for plunger rod drive has come in contact with a stopper. As a result, the generation of a fluid dynamic force that impels the valve member in the valve closing direction towards the surface on the opposite side to the sheet surface of the valve member, as a result of fuel spilled from a pressurizing chamber, is reduced. Furthermore, the protector and the suction valve member do not come in contact, so noise generation does not increase. As a result, a high-pressure fuel supply pump can be provided that is capable of accurate flow rate control even if capacity is increased, and has little noise generation.

Description

technical field [0001] The present invention relates to a high-pressure fuel supply pump used in an in-cylinder injection type internal combustion engine and provided with an electromagnetically driven suction valve mechanism, and more particularly to a high-pressure fuel supply pump provided with an electromagnetically driven suction valve mechanism as follows, The electromagnetically driven suction valve mechanism described above is a so-called normally closed electromagnetically driven suction valve in which the valve member and the plunger rod are integrated, and the spring biasing the plunger rod biases the valve member in the valve closing direction. mechanism. Background technique [0002] In the high-pressure fuel supply pump provided with the electromagnetically driven suction valve mechanism described in Japanese Patent Application Laid-Open No. 2006-250086, the movable plunger operated by electromagnetic force of the electromagnetically driven suction valve mechan...

AI Technical Summary

Problems solved by technology

When the fluid force of the recirculating fuel flow increases due to the increase in capacity, a correspondingly large electromagnetic force is required to maintain the valve open state without being affected by the fluid force, and there is a problem that the electromagnetic drive mechanism becomes larger.

If the standpoint is changed, there is also the following problem: when the fluid force acting on the valve member in the valve closing direction becomes larger than the magnetic attraction force at an unexpected moment, the valve member becomes closed in contact with the suction valve seat. Valve status, inability to perform accurate flow control, or inability to reduce the holding current after the starting current of the electromagnetic drive mechanism

[0011] In addition, in the electromagnetically driven suction valve mechanism described in the latter patent document, when the suction valve member is in the fully open valve state, there is a problem that it collides with the flapper to generate noise.

In the electromagnetic drive type suction valve mechanism of this patent document, the collision sound of the plunger and the restricting member, the collision sound of the armature (anchor) provided on the plunger rod and the fixed core, the front end of the plunger rod and the suction valve are generated. There is a problem that there are many sound generating parts due to the collision sound of components

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