# US 11,441,558 B2 · Guide for piston of high-pressure pump for vehicle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,441,558 B2 - Document ID: US11441558B2 - Status: Granted - Kind: B2 - Application number: 17/122,463 - Filed: 2020-12-15 - Published: 2021-06-17 - Granted: 2022-09-13 - Earliest claimed: 2019-12-17 - Assignees: Hyundai Kefico Corporation - Applicants: Hyundai Kefico Corporation - Inventors: Kyung Chul Han; Hyeong Kyun Park; Jin Sung Kim; Chun Ky Hong - Web page: https://patentgrep.com/patent/US11441558B2 ## CPC - F04B 53/16: Casings; Cylinders; Cylinder liners or heads; Fluid connections - F02M 59/442: {means preventing fuel leakage around pump plunger, e.g. fluid barriers} - F04B 1/0439: Supporting or guiding means for the pistons - F04B 1/053: with actuating or actuated elements at the inner ends of the cylinders - F04B 19/04: Pumps for special use - F04B 53/14: Pistons, piston-rods or piston-rod connections - F04B 53/164: {Stoffing boxes} - 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 2200/16: Sealing of fuel injection apparatus not otherwise provided for - 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) - F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF ## Abstract A guide for a piston of a high-pressure pump includes: an upper body and a lower body, a connection part integrally connecting the upper body and the lower body, and a seal molded by an insert injection between the upper body and the lower body while surrounding the connection part. A gap exists between the upper body and the lower body, and the piston and the seal are in close contact with a piston. Therefore, it is possible to prevent leakage of fuel even while securing motion performance of the piston. ## Claims ### Claim 1 A guide for a piston of a high-pressure pump, the guide comprising: an upper body and a lower body having a cylindrical shape; a plurality of connection parts integrally formed on the upper body and the lower body to connect the upper body to the lower body; and a seal provided in a space between the upper body and the lower body in a structure of surrounding the connection part, wherein the seal is formed with connection part holes of a same number as a number of the connection parts, and wherein each of the connection part holes vertically penetrates the seal, and wherein each of the connection parts is inserted into one of the connection part holes, and wherein the seal is molded by an insert injection in a space between the upper body and the lower body. ### Claim 2 (depends on 1) The guide for the piston of the high-pressure pump of claim 1, wherein a piston hole into which the piston is inserted are formed in the upper body and the lower body, respectively, and wherein diameters of the piston holes are formed such that a gap exists between an inner circumferential surface of each of the piston holes and an outer circumferential surface of the piston. ### Claim 3 (depends on 1) The guide for the piston of the high-pressure pump of claim 1, wherein the seal is formed with a piston hole into which the piston is inserted, and wherein an inner circumferential surface of the piston hole is in close contact with an outer circumferential surface of the piston. ### Claim 4 (depends on 1) The guide for the piston of the high-pressure pump of claim 1, wherein the seal has a side groove in a side surface thereof, and wherein a plate spring pushing an inner wall surface of the side groove toward the piston is installed in the side groove. ### Claim 5 (depends on 4) The guide for the piston of the high-pressure pump of claim 4, wherein the plate spring comprises: a bending part connecting support parts on both sides having a plate shape to a lower end of the support parts on both sides and wherein one side of the support parts on both sides is supported by a housing of the high-pressure pump and an opposite side of the support parts on both sides is supported by an inner wall surface of the side groove. ### Claim 6 (depends on 1) The guide for the piston of the high-pressure pump of claim 1, wherein the seal has a lip having a ring shape vertically formed in a plurality of columns, the lip being disposed on an inner circumferential surface of a piston hole of the piston and in close contact with an outer circumferential surface of the piston. ### Claim 7 (depends on 1) The guide for the piston of the high-pressure pump of claim 1, wherein piston holes into which the piston is inserted are formed in the upper body and the lower body, respectively, and wherein an inner diameter of each of the piston holes of the lower body is formed larger than an inner diameter of each of the piston holes of the upper body. ### Claim 8 (depends on 1) The guide for the piston of the high-pressure pump of claim 1, wherein a gripping part having a reduced diameter is formed on a lower end of the lower body, and the gripping part protrudes to an outside of a guide installation hole of a housing of the high-pressure pump.