# US 2014/0193280 A1 · High-pressure fuel supply pump > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0193280 A1 - Document ID: US20140193280A1 - Status: Published application - Kind: A1 - Application number: 14/238,685 - Filed: 2012-08-07 - Published: 2014-07-10 - Earliest claimed: 2011-09-20 - Assignees: Hitachi Automotive Systems, Ltd. - Inventors: Atsuji Saito - Web page: https://patentgrep.com/patent/US20140193280A1 ## CPC - F02M 55/04: Means for damping vibrations {or pressure fluctuations} in injection pump inlets {or outlets} - B23K 26/20: Bonding (soldering by means of radiant energy B23K1/005) - F02M 21/0245: {High pressure fuel supply systems; Rails; Pumps; Arrangement of valves} - F02M 59/44: 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} - F02M 59/48: Assembling; Disassembling; Replacing - F04B 11/00: Equalisation of pulses, e.g. by use of air vessels; Counteracting cavitation - F04B 11/0016: {with a fluid spring} - F04B 11/0033: {with a mechanical spring} - F02M 2200/8084: involving welding or soldering - Y02T 10/30: Use of alternative fuels, e.g. biofuels - F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF - B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM - F04B: POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS (machines for liquids, or pumps, of rotary-piston or oscillating-piston type F04C; non-positive-displacement pumps F04D; pumping of fluid by direct contact of another fluid or by using inertia of fluid to be pumped F04F) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## 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. ## Claims ### Claim 1 A high-pressure fuel supply pump comprising a pump housing in which a pressurizing chamber is formed, and a low-pressure fuel path which is formed upstream of the pressurizing chamber, wherein: the pump housing has a damper storage room in a bottomed tubular shape formed in the middle of the low-pressure fuel path, the damper storage room stores a damper, the high-pressure fuel supply pump comprises a cover whose outer edge engages with a tubular step part formed on the inner circumference of an open end part of the damper storage room, the high-pressure fuel supply pump comprises an elastic body which is sandwiched between the cover and the damper, the damper is sandwiched between the cover and the housing via the elastic body, the interfacial part between the tubular part and the outer edge of the cover is joined by laser welding, and the welding mark is formed on a top part of the cover. ### Claim 2 (depends on 1) The high-pressure fuel supply pump according to claim 1, wherein: a mechanism for attenuating pressure pulsation occurring on a low-pressure side is provided in the damper storage room, an elastic body is provided between the cover and the pressure pulsation reducing mechanism, and the high-pressure fuel supply pump comprises fixation means which fixes the outer edge of the cover with respect to the inner circumferential surface of the damper storage room facing the outer edge in a state in which the elastic body has been compressed. ### Claim 3 (canceled) ### Claim 4 (canceled) ### Claim 5 (depends on 1) The high-pressure fuel supply pump according to claim 1, wherein the welding part is situated inside the external diameter of the pump housing. ### Claim 6 (depends on 1) The high-pressure fuel supply pump according to claim 1, wherein: the tubular part of the pump housing is provided with a step part, and the cover is set on the step part. ### Claim 7 (depends on 6) The high-pressure fuel supply pump according to claim 6, wherein a gap is formed at a corner part of the step part. ### Claim 8 (depends on 1) The high-pressure fuel supply pump according to claim 1, wherein fixation means is implemented by tensile joining. ### Claim 9 (depends on 1) The high-pressure fuel supply pump according to claim 1, wherein fixation means is implemented by friction stir welding. ### Claim 10 A damper mechanism comprising: a housing part which has a damper storage room in a bottomed tubular shape; a damper which is stored in the damper storage room; a cover whose outer edge engages with a tubular step part formed on the inner circumference of an open end part of the damper storage room; and an elastic body which is sandwiched between the cover and the damper, wherein: an outer edge of the dampercover and an engagement part formed at the tubular step part of the housing part are joined together by laser welding, and the welding mark is formed on a top part of the cover. ### Claim 11 (canceled) ### Claim 12 (depends on 10) The damper mechanism according to claim 10, wherein a gap for capturing spatters is formed at a corner part of the tubular step part. ### Claim 13 A method for manufacturing a damper mechanism having a damper stored in a concave part of a housing and a cover fixed to the housing and hermetically enclosing the damper in the concave part, wherein: an elastic body is provided between the cover and the damper, the outer edge of the cover is fixed with respect to the inner circumferential surface of a damper storage room facing the outer edge by using fixation means in a state in which the elastic body has been compressed, the fixation means is implemented by laser welding from above the cover. ### Claim 14 (canceled) ### Claim 15 (depends on 13) The method for manufacturing a damper mechanism according to claim 13, wherein the fixation means is implemented by tensile joining. ### Claim 16 (depends on 13) The method for manufacturing a damper mechanism according to claim 13, wherein the fixation means is implemented by friction stir welding.