# US 10,309,393 B2 · High-pressure pump and production method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,309,393 B2 - Document ID: US10309393B2 - Status: Granted - Kind: B2 - Application number: 15/543,778 - Filed: 2015-12-22 - Published: 2018-01-11 - Granted: 2019-06-04 - Earliest claimed: 2015-01-20 - Assignees: Denso Corporation - Applicants: Denso Corporation - Inventors: Masaharu Nakaoka - Web page: https://patentgrep.com/patent/US10309393B2 ## CPC - F04B 53/16: Casings; Cylinders; Cylinder liners or heads; Fluid connections - F02M 59/26: caused by movements of pistons relative to their cylinders - 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 59/445: {Selection of particular materials} - F02M 59/48: Assembling; Disassembling; Replacing - F04B 1/0408: Pistons - F04B 1/0413: Cams - F04B 1/0421: Cylinders - F04B 1/053: with actuating or actuated elements at the inner ends of the cylinders - F04B 7/0076: {the members being actuated by electro-magnetic means} - F04B 11/00: Equalisation of pulses, e.g. by use of air vessels; Counteracting cavitation - F04B 53/14: Pistons, piston-rods or piston-rod connections - F04B 53/162: {Adaptations of cylinders} - B21D 31/04: Expanding other than provided for in groups B21D1/00 - B21D28/00, e.g. for making expanded metal (B21D47/00 takes precedence; enlarging tube ends B21D41/02) - B21D 39/04: of tubes with tubes; of tubes with rods {(crimped pipe joints as such F16L13/14)} - F04B 19/22: of reciprocating-piston type - F04B 53/22: Arrangements for enabling ready assembly or disassembly - 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 - B21D: WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL (working or processing of wire B21F) ## Abstract A pump body of a high-pressure pump includes a pressure chamber formed in a deep portion of a cylinder. The pump body closes the pressure chamber on a side opposite to a plunger. The plunger reciprocates within the cylinder to vary a volume of the pressure chamber. The large-diameter portion provided at an end of the plunger on a side protruding to the pressure chamber has an outside diameter larger than an inside diameter of the cylinder and smaller than an inside diameter of the pressure chamber. In this case, the large-diameter portion is engaged with a step portion between the cylinder and the pressure chamber in a state before attachment of the high-pressure pump to an internal combustion engine. Accordingly, separation of the plunger from the cylinder is avoidable. ## Claims ### Claim 1 A high-pressure pump comprising: a pump body including a cylinder and a pressure chamber, the pressure chamber having a larger inside diameter than an inside diameter of the cylinder, the pressure chamber being disposed at a deep end of the cylinder, the pump body closing the pressure chamber on a side opposite to the cylinder; a plunger that reciprocates within the cylinder to vary a volume of the pressure chamber; and a large-diameter portion having an outside diameter larger than the inside diameter of the cylinder, and smaller than the inside diameter of the pressure chamber in a condition where the pump body and the plunger are at a normal temperature, the large-diameter portion being provided at an end of the plunger on a side protruding to the pressure chamber, wherein in a condition where a temperature of the pump body is higher than a temperature of the large-diameter portion, the inside diameter of the cylinder is larger than the outside diameter of the large-diameter portion. ### Claim 2 (depends on 1) The high-pressure pump according to claim 1, wherein: a portion of the pump body forming the cylinder and the rest of the pump body are unitary. ### Claim 3 (depends on 1) The high-pressure pump according to claim 1, wherein: the large-diameter portion and the plunger are unitary. ### Claim 4 (depends on 1) The high-pressure pump according to claim 1, wherein: the large-diameter portion and the plunger are unitary; a portion of the pump body forming the cylinder and the rest of the pump body are unitary. ### Claim 5 (depends on 1) The high-pressure pump according to claim 1, wherein: the large-diameter portion and the plunger are made of different materials; and a linear expansion coefficient of the large-diameter portion is larger than a linear expansion coefficient of the plunger. ### Claim 6 (depends on 1) A production method for producing the high-pressure pump according to claim 1, the method comprising: a temperature control process for performing at least either heating the cylinder or cooling the large-diameter portion to allow the inside diameter of the cylinder to become larger than the outside diameter of the large-diameter portion, or allow the outside diameter of the large-diameter portion to become smaller than the inside diameter of the cylinder; an insertion process for inserting the plunger into the cylinder; and a normal temperature control process for allowing resultant temperatures of the cylinder and the large-diameter portion to approach temperatures of the cylinder and the large-diameter portion before the temperature control process. ### Claim 7 (depends on 1) The high-pressure pump according to claim 1, wherein: in the condition where the temperature of the pump body is higher than the temperature of the large-diameter portion, the pump body allows insertion of the large-diameter portion into the pressure chamber from an opening of the cylinder on an side opposite to the pressure chamber. ### Claim 8 (depends on 7) The high-pressure pump according to claim 7, wherein: in the condition where the pump body and the plunger are at the normal temperature, the large diameter portion is engaged with a step portion of the pump body between the cylinder and the pressure chamber to avoid separation of the plunger from the cylinder. ### Claim 9 (depends on 8) The high-pressure pump according to claim 8, wherein: in the condition where the pump body and the plunger are at the normal temperature, the outside diameter of the large-diameter portion is larger than the inside diameter of the cylinder by a difference of several micrometers.