High-pressure fuel pump

Patent metadata

Field	Value
Publication number	US-10253741-B2
Application number	US-201615566060-A
Country	US
Kind code	B2
Filing date	Apr 15, 2016
Priority date	May 12, 2015
Publication date	Apr 9, 2019
Grant date	Apr 9, 2019

Abstract

An object is to suppress cavitation generated at a distal end portion of a seat face when a valve body and a seat portion collide with each other. In a relief valve of a fuel pump, an intersection between the seat face and a flow channel hole is formed at a position more distant than the seat portion formed of the valve body in a valve closing state and the seat face in order to suppress generation of cavitation bubbles when the valve body improves and releases high-pressure fuel.

First claim

The invention claimed is:

1. A high-pressure fuel pump comprising:
a pressurizing chamber to pressurize fuel;
a discharge valve disposed on a downstream side of the pressurizing chamber; and
a relief valve mechanism that causes fuel in a discharge path on the downstream side of the discharge valve to return to the pressurizing chamber or a low-pressure path, wherein the relief valve mechanism comprises:
a relief path formed to be connected to the discharge path; a relief seat face connected to the relief path and formed to be enlarged toward the pressurizing chamber or the low-pressure path; and a relief valve body positioned to be closer to the pressurizing chamber side or the low-pressure path side than the relief seat face and seated on the relief seat face, and
an intersection between the relief path and the relief seat face is positioned closer to the discharge path side than an end portion of the relief valve body on the discharge path side
wherein the relief seat face is polished on the pressurizing chamber side of the low pressure path side from an intersection between the relief path and the relief seat face
wherein a diameter of the relief path is equal to or smaller than 0.6 times of a seat diameter of the relief seat face.

2. A high-pressure fuel pump comprising:
a pressurizing chamber to pressurize fuel;
a discharge valve disposed on a downstream side of the pressurizing chamber; and
a relief valve mechanism that causes fuel in a discharge path on the downstream side of the discharge valve to return to the pressurizing chamber or a low-pressure path,
wherein the relief valve mechanism comprises: a relief path formed to be connected to the discharge path; a relief seat face connected to the relief path and formed to be enlarged toward the pressurizing chamber or the low-pressure path; and a relief valve body positioned to be closer to the pressurizing chamber side or the low-pressure path side than the relief seat face and seated on the relief seat face, and
a diameter of the relief path is equal to or smaller than 0.6 times of a seat diameter of the relief seat face.

3. A high-pressure fuel pump comprising:
a pressurizing chamber to pressurize fuel;
a discharge valve disposed on a downstream side of the pressurizing chamber; and
a relief valve mechanism that causes fuel in a discharge path on the downstream side of the discharge valve to return to the pressurizing chamber or a low-pressure path,
wherein the relief valve mechanism comprises: a relief path formed to be connected to the discharge path; a relief seat face connected to the relief path and formed to be enlarged toward the pressurizing chamber or the low-pressure path; and a relief valve body positioned to be closer to the pressurizing chamber side or the low-pressure path side than the relief seat face and seated on the relief seat face, and
a diameter of the relief path is formed to be equal to or smaller than a half of a diameter of the relief valve body.

4. The high-pressure fuel pump according to claim 1 , wherein
an intersection is formed without an R portion as the relief path and the relief seat face intersect each other at a predetermined angle.

5. The high-pressure fuel pump according to claim 1 , wherein
the relief path is formed substantially in parallel with an extension and contraction direction of a spring portion that biases the relief valve body, and
the relief seat face is formed to be tilted to an outer periphery side at an angle of 50 degrees or smaller with respect to the relief path.

Assignees

• Hitachi Automotive Systems Ltd

Inventors

• Akiyama Moritsugu
• Omata Shigehiko
• Kobayashi Katsutoshi
• Tokuo Kenichiro

Classifications

• F02M59/025

  characterised by a single piston · CPC title

• F02M63/0036 Primary

  with spherical or partly spherical shaped valve member ends · CPC title

• F02M63/0245

  between the high pressure pump and the common rail · CPC title

• F02M55/02

  Conduits between injection pumps and injectors {, e.g. conduits between pump and common-rail or conduits between common-rail and injectors} · CPC title

• F02M63/026 Primary

  Means for reducing the pressure in common rails at power off (pressure control F02D41/3845) · CPC title