High-pressure fuel supply pump

Patent metadata

Field	Value
Publication number	US-9624916-B2
Application number	US-201214238685-A
Country	US
Kind code	B2
Filing date	Aug 7, 2012
Priority date	Sep 20, 2011
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

The damper mechanism used for a high-pressure fuel supply pump system is configured so that an outer circumferential surface of a cover in regard to the thickness direction of the base material of the cover engages with the inner circumference of an open end part of a bottomed tubular concave part formed in a damper housing or in a pump housing of the high-pressure fuel supply pump. The total height of the damper as a low-pressure pulsation reducing mechanism can be reduced and the dimensions of the damper in the radial directions can also be reduced. In cases where the damper mechanism is formed integrally with the high-pressure fuel supply pump, the total height of the high-pressure fuel supply pump can be reduced and the dimensions of the damper part in the radial directions can also be reduced.

First claim

The invention claimed is:

1. A fuel supply pump comprising:
a pressurizing chamber of a pump housing;
a damper storage room formed in a fluidly upstream side of the pressurizing chamber;
a damper stored in the damper storage room;
a cover configured to close an opening end of the damper storage room with an elastic body sandwiched between the cover and the damper; and
a face welding part formed between an outer circumferential part of the cover and an inner circumferential part of the damper storage room, wherein the face welding part when welded forms a flush surface with the cover and the damper storage room in a direction parallel to a reciprocating direction.

2. The fuel supply pump according to claim 1 ,
wherein the pump housing includes an intake joint along a top portion of the pump housing;
wherein the damper storage room is formed in a bottomed tubular shape, wherein the tubular shape extends along a first axis perpendicular to the reciprocating direction of a position;
wherein the damper is fixed to the pump housing by a damper holder and the damper includes a top portion offset from a bottom portion along a second axis that is parallel to the reciprocating direction of a position axis; and wherein
the fuel supply pump further comprises:
a first fuel path that extends along the second axis that is perpendicular to the first axis and connects the intake joint to an intake fuel path, wherein the intake path extends around the damper holder so that low-pressure fuel evenly acts on both the top portion of the damper and the bottom portion of the damper.

3. The fuel supply pump according to claim 2 , wherein the cover is at least partially stored in the tubular part of the damper storage room.

4. The fuel supply pump according to claim 1 , wherein outer circumferences of two diaphragms are welded together in an inner region of the face welding part to form the damper.

5. The fuel supply pump according to claim 1 , wherein the damper is arranged closer to a bottom part of the damper storage room than the face welding part is.

6. The fuel supply pump according to claim 1 , wherein the damper further comprises a brim part at an outer circumference of the damper and the elastic body butts the brim part directly.

7. The fuel supply pump according to claim 1 , wherein the elastic body has a U-shaped cross section extending in a circumferential direction.

8. The fuel supply pump according to claim 1 , wherein the elastic body has a plurality of through holes communicating between an inner space and an outer space of the elastic body.

9. A damper mechanism comprising:
a pressurizing chamber;
a damper storage room formed in a fluidly upstream side of the pressurizing chamber;
a damper stored in the damper storage room;
a cover arranged in an opening end of the damper storage room with an elastic body sandwiched between the cover and the damper; and
an annular welding portion exposed in a direction parallel to a reciprocating direction, wherein the annular welding portion joins an outer circumferential part of the cover and an inner circumferential part of the damper storage room and the annular welding portion when welded forms a flush surface with the cover and the damper storage room.

10. The damper mechanism according to claim 9 ,
wherein the damper storage room is formed in a bottomed tubular shape, wherein the tubular shape extends along a first axis perpendicular to the reciprocating direction of the piston;
wherein the damper is fixed to a housing of the damper storage room by a damper holder and the damper includes a top portion offset from a bottom portion along a second axis that is parallel to the reciprocating direction of the piston; and
wherein the damper mechanism further comprises:
a first fuel path that connects an intake joint to an intake fuel path, wherein the first fuel path extends along the second axis that is perpendicular to the first axis, wherein the intake path extends around the damper holder so that low-pressure fuel evenly acts on both the top portion of the damper and the bottom portion of the damper.

11. The damper mechanism according to claim 10 , wherein the cover is at least partially stored in the tubular part of the damper storage room.

12. The damper mechanism according to claim 9 , wherein outer circumferences of two diaphragms are welded together in an inner region of the annular welding portion to form the damper.

13. The damper mechanism according to claim 9 , wherein the damper is arranged closer to a bottom part of the damper storage room than the annular welding portion is.

14. The damper mechanism according to claim 9 , wherein the damper further comprises a brim part at an outer circumference of the damper and the elastic body butts the brim part directly.

15. The damper mechanism according to claim 9 , wherein the elastic body has a U-shaped cross section extending in a circumferential direction.

16. The damper mechanism according to claim 9 , wherein the elastic body has a plurality of through holes communicating between an inner space and an outer space of the elastic body.

17. A method for manufacturing a fuel supply pump comprising:
forming a damper storage room in a bottomed tubular shape, wherein the tubular shape extends along a reciprocating direction of a piston, in a pump housing which has a pressurizing chamber;
fixing a damper in the damper storage room by a damper holder;
providing an elastic body mechanically coupled to the damper;
mechanically coupling a cover to the elastic body to close an opening end of a tubular part of the damper storage room with the elastic body sandwiched between the cover and the damper;
forming an annular welding portion that is exposed in a direction parallel to the reciprocating direction between an inner circumference of the tubular part of the damper storage room; and
welding the annular welding portion to form a flush surface with the cover and the damper storage room, wherein the welding is performed by applying a laser beam to an interfacial part between the cover and the inner circumference of the tubular part of the damper storage room from above the cover along the reciprocating direction.

Assignees

• Saito Atsuji
• Hitachi Automotive Systems Ltd

Inventors

• Saito Atsuji

Classifications

• F02M59/44

  Details, components parts, or accessories not provided for in, or of interest apart from, the apparatus of groups F02M59/02 - F02M59/42; {Pumps having transducers, e.g. to measure displacement of pump rack or piston} · CPC title

• F04B11/0033

  with a mechanical spring · CPC title

• F02M55/04 Primary

  Means for damping vibrations {or pressure fluctuations} in injection pump inlets {or outlets} · CPC title

• F02M2200/8084

  involving welding or soldering · CPC title

• F02M21/0245

  High pressure fuel supply systems; Rails; Pumps; Arrangement of valves · CPC title