High-pressure fuel supply pump

Patent metadata

Field	Value
Publication number	US-2017191456-A1
Application number	US-201715467601-A
Country	US
Kind code	A1
Filing date	Mar 23, 2017
Priority date	Sep 20, 2011
Publication date	Jul 6, 2017
Grant date	—

Abstract

The damper mechanism used for a high-pressure fuel supply pump 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

1 . A fuel supply pump comprising:
a pressurizing chamber formed in a pump housing; a low-pressure fuel chamber that is formed in fluidly upstream side of the pressurizing chamber, the low-pressure fuel chamber formed in a bottomed tubular part; a damper that is stored in the low-pressure fuel chamber; and a damper cover that is mounted over the damper with a damper holder sandwiched between the damper cover and the damper, wherein the damper cover is arranged in a tubular part of the low-pressure fuel chamber so that an outermost edge of the damper cover engages with an inner circumference of the tubular part of the low-pressure fuel chamber.

2 . The fuel supply pump according to claim 1 , wherein
an annular welding portion joins the outermost edge of the damper cover and the inner circumference of the tubular part of the low-pressure fuel chamber.

3 . The fuel supply pump according to claim 2 , wherein
the annular welding portion is exposed upward of the damper cover.

4 . The fuel supply pump according to claim 1 , wherein
the damper holder has:
an upper edge part that is in an annular contact with the damper cover;
a lower edge part that is in an annular contact with the damper;
a curved part that connects the upper edge part ( 91 b ) and the lower edge part; and
a plurality of through-holes that is formed in the curved part.

5 . The fuel supply pump according to claim 5 , wherein
the damper has two metallic diaphragms that are welded together in their peripheral edges, and the lower edge part of the damper holder is in contact with a brim part of the damper that is formed inward of a welding part of the damper.

6 . The fuel supply pump according to claim 1 , wherein
the damper cover has ribs in radiation directions.

7 . The fuel supply pump according to claim 1 , further comprising:
an inlet valve that is arranged at an inlet of the pressurizing chamber; a discharge valve that is arranged at an outlet of the pressurizing chamber; and a relief valve that is configured to return the fuel discharged from the discharge valve into the pressurizing chamber.

Assignees

• Hitachi Automotive Systems Ltd

Inventors

• Saito Atsuji

Classifications

• F02M55/04 Primary

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

• 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

• F02M59/48

  Assembling; Disassembling; Replacing · CPC title

• F02M21/0245

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

• F04B11/00

  Equalisation of pulses, e.g. by use of air vessels; Counteracting cavitation · CPC title