Damper mechanism and high pressure fuel pump
AssigneeHitachi, Ltd.
InventorsSatoshi Usui, Minoru Hashida
Life of this patent
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Abstract
To obtain a small and high performance damper mechanism which reduces pressure pulsation in low pressure-side fuel in the high pressure fuel pump in a high pressure fuel supply system or a high pressure fuel pump provided with the small and high performance damper mechanism. Two metal diaphragms are welded together over the entire circumference to obtain a metal diaphragm assembly (also referred to as “double metal diaphragm damper”). The whole or part of the portion of the metal diaphragm assembly other than the weld (for example, the portion inside the weld) is clamped by a pressing member and thereby the assembly is secured in a housing enclosure. The housing enclosure may be formed integrally with the body of a high pressure pump.
Claims33
A damper mechanism which is provided at a low pressure-side passage leading to the pressure chamber of a pump for pressurizing fuel and reduces fuel pressure pulsation,
- wherein at least one set of metal diaphragm assembly each comprising two metal diaphragms welded together over the entire circumference is provided and gas is sealed therein,
- said diaphragm assembly is housed in a housing portion leading to said low pressure-side passage,
- the housing portion is sealed from the outside air with a lid,
- said damper mechanism further comprises a pair of retaining members which clamp the diaphragm assembly from above and below inside the weld of said metal diaphragms, and
- part of force which secures said lid on said housing portion is exerted on said diaphragm assembly through said retaining members and said diaphragm assembly is thereby secured in said housing portion.
A high pressure fuel pump for pressurizing and supplying fuel to an internal combustion engine, comprising:
- a low pressure-side passage integrally formed in the body of the pump;
- and a damper mechanism which is installed in the low pressure-side passage and reduces fuel pressure pulsation,
- wherein said damper mechanism comprises at least one set of metal diaphragm assembly each comprising two metal diaphragms welded together over the entire circumference and gas is sealed therein,
- said diaphragm assembly is housed in a housing portion formed integrally with said low pressure-side passage and the housing portion is sealed from the outside air with a lid,
- said damper mechanism further comprises a pair of retaining members which clamp the diaphragm assembly from above and below inside the weld of said metal diaphragms, and
- part of force which secures said lid on the body of said pump to seal said housing portion is exerted on said diaphragm assembly through said retaining members and said diaphragm assembly is thereby secured in said pump body.
A high pressure fuel pump comprising:
- a pressure chamber for pressurizing fuel;
- a plunger which pressurizes and feeds the fuel in said pressure chamber;
- an intake valve installed at the fuel inlet of said pressure chamber;
- and a delivery valve installed at the fuel outlet of said pressure chamber,
- wherein a plurality of double metal diaphragm dampers are provided in a fuel passage positioned upstream from said intake valve, each of which double metal diaphragm dampers is formed by welding together the rims of two metal diaphragms to seal gas in between said two metal diaphragms.
A high pressure fuel pump comprising:
- a pressure chamber for pressurizing fuel;
- a plunger which pressurizes and feeds the fuel in said pressure chamber;
- an intake valve installed at the fuel inlet of said pressure chamber;
- a delivery valve installed at the fuel outlet of said pressure chamber;
- and a double metal diaphragm damper which is formed by welding together the rims of two metal diaphragms to seal gas in between said two metal diaphragms and is provided in a fuel passage positioned upstream from said intake valve,
- wherein the securing portion of said double metal diaphragm damper is other than said weld.
Dependencies are inferred from the claim text.