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DE-112018005024-B4 - HIGH-PRESSURE PUMP

DE112018005024B4DE 112018005024 B4DE112018005024 B4DE 112018005024B4DE-112018005024-B4

Abstract

High-pressure pump (10), comprising: a pressurization chamber formation section (23) which defines a pressurization chamber (200) in which fuel is pressurized; a discharge passage formation section (21) defining a discharge passage (217) through which the fuel flows which is discharged from the pressurization chamber (200); a discharge seat element (71) arranged in the discharge passage (217), wherein the discharge seat element (71) comprises the following: a discharge hole (73) passing through the discharge seat element (71) between a surface facing the pressurization chamber (200) and the other surface facing away from the pressurization chamber (200); and a discharge valve seat (74) located around the discharge hole (73) on the other surface of the discharge seat element (71), which is arranged facing away from the pressurization chamber (200); an intermediate element (81) arranged on one side of the discharge seat element (71) opposite the pressurization chamber (200), wherein the intermediate element (81) includes a first passage (83) passing through the intermediate element (81) between a surface facing the pressurization chamber (200) and the other surface facing away from the pressurization chamber (200); an overflow seat element (85) arranged on one side of the intermediate element (81) opposite the pressurization chamber (200), wherein the overflow seat element (85) comprises the following: an overflow hole (87) passing through the overflow seat element (85) between a surface facing the pressurization chamber (200) and the other surface facing away from the pressurization chamber (200); an overflow valve seat (88) is located around the overflow hole (87) on one surface of the overflow seat element (85) that faces the pressurization chamber (200); and a second passage (89) through the overflow seat element (85) between one surface which is arranged facing the pressurization chamber (200) and the other surface which is arranged away from the pressurization chamber (200); a drain valve (75) arranged between the intermediate element (81) and the drain seat element (71), wherein the drain valve (75) is able to allow fuel flow through the drain hole (73) by separating from the drain valve seat (74) to open the drain hole (73), and to restrict fuel flow through the drain hole (73) by contacting the drain valve seat (74) to close the drain hole (73); and a bypass valve (91) arranged between the intermediate element (81) and the bypass seat element (85), wherein the bypass valve (91) is able to allow fuel flow through the bypass hole (87) by separating from the bypass valve seat (88) to open the bypass hole (87), and to restrict fuel flow through the bypass hole (87) by contacting the bypass valve seat (88) to close the bypass hole (87), wherein at least one selected from the intermediate element (81) and the overflow seat element (85) includes an annular recess (800) which has an annular shape and fluidly connects the first passage (83) and the second passage (89), and the annular recess (800) is recessed starting from a surface of the at least one selected from the intermediate element (81) and the overflow seat element (85), which are arranged facing each other, wherein the annular recess (800) is arranged between the first passage (83) and the second passage (89) and is in direct fluid communication with both the first passage (83) and the second passage (89).

Inventors

  • Shinichiro Koshimoto
  • Yoshihito Suzuki
  • Takayuki Makihara

Assignees

  • DENSO CORPORATION

Dates

Publication Date
20260513
Application Date
20180928
Priority Date
20170929

Claims (7)

  1. High-pressure pump (10), comprising: a pressurization chamber formation section (23) defining a pressurization chamber (200) in which fuel is pressurized; a discharge passage formation section (21) defining a discharge passage (217) through which the fuel flows that is discharged from the pressurization chamber (200); a discharge seat element (71) arranged in the discharge passage (217), the discharge seat element (71) comprising: a discharge hole (73) passing through the discharge seat element (71) between a surface facing the pressurization chamber (200) and the other surface facing away from the pressurization chamber (200); and a discharge valve seat (74) located around the discharge hole (73) on the other surface of the discharge seat element (71) facing away from the pressurization chamber (200); an intermediate element (81) located on one side of the discharge seat element (71) opposite the pressurization chamber (200), the intermediate element (81) comprising a first passage (83) passing through the intermediate element (81) between a surface facing the pressurization chamber (200) and the other surface facing away from the pressurization chamber (200); a bypass seat element (85) arranged on one side of the intermediate element (81) opposite the pressurization chamber (200), the bypass seat element (85) comprising: a bypass hole (87) passing through the bypass seat element (85) between a surface facing the pressurization chamber (200) and the other surface facing away from the pressurization chamber (200); a bypass valve seat (88) located around the bypass hole (87) on one surface of the bypass seat element (85) facing the pressurization chamber (200); and a second passage (89) passing through the bypass seat element (85) between one surface facing the pressurization chamber (200) and the other surface facing away from the pressurization chamber (200); a drain valve (75) arranged between the intermediate element (81) and the drain seat element (71), wherein the drain valve (75) is able to allow the fuel flow through the drain hole (73) by moving it away from the The drain valve seat (74) separates to open the drain hole (73) and restricts the fuel flow through the drain hole (73) by contacting the drain valve seat (74) to close the drain hole (73); and a bypass valve (91) arranged between the intermediate element (81) and the bypass seat element (85), wherein the bypass valve (91) is able to allow fuel flow through the bypass hole (87) by separating from the bypass valve seat (88) to open the bypass hole (87), and to restrict fuel flow through the bypass hole (87) by contacting the bypass valve seat (88) to close the bypass hole (87), wherein at least one selected from the intermediate element (81) and the bypass seat element (85) includes an annular recess (800) having an annular shape and fluidly connecting the first passage (83) and the second passage (89), and the annular recess (800) is recessed from a surface of the at least one selected from the intermediate element (81) and the bypass seat element (85) which are arranged facing each other, wherein the annular recess (800) is arranged between the first passage (83) and the second passage (89) and is in direct fluid communication with both the first passage (83) and the second passage (89).
  2. High-pressure pump (10) after Claim 1 , wherein the first passage (83) is one selected from a plurality of first passages arranged in a circumferential direction of the intermediate element (81), and the second passage (89) is one selected from a plurality of second passages arranged in a circumferential direction of the overflow seat element (85).
  3. High-pressure pump (10) after Claim 2 , where a number of the plurality of first passages (83) differs from a number of the plurality of second passages (89).
  4. High-pressure pump (10) after Claim 3 , wherein the number of the plurality of first passages (83) is greater than the number of the plurality of second passages (89), and the annular recess (800) is formed in the intermediate element (81).
  5. High-pressure pump (10) after Claim 4 , where the number of first plural passages (83) and the number of second plural passages (89) are relatively prime.
  6. High-pressure pump (10) after one of the Claims 1 until 5 , wherein the number of the plurality of first passages (83) is greater than the number of a plurality of second passages (89), and a length of each of the plurality of first passages (83) is less than a length of each of the plurality of second passages (89).
  7. High-pressure pump (10) after one of the Claims 1 until 6 , further comprising a discharge port (70) having a cylindrical shape to enclose the discharge seat element (71), the intermediate element (81), the overflow seat element (85), the discharge valve (75) and the overflow valve (91), wherein the discharge port (70) includes an outer peripheral wall which is joined to the discharge passage forming section (21).

Description

Cross-reference to similar registration This application is based on the Japanese patent application with the number... 2017-190 632 , filed on September 29, 2017, and on the Japanese patent application with the number 2018-176 427 , submitted on September 20, 2018. Technical field The present disclosure relates to a high-pressure pump. State of the art A high-pressure pump, conventionally known as a pump for pressurizing and supplying fuel to an internal combustion engine, includes a bypass valve for releasing fuel to a pressurized or low-pressure chamber when the pressure of the fuel discharged from the pressurized chamber reaches a predetermined value or higher. According to a high-pressure pump described in patent literature 1, for example, a bypass valve is configured to release fuel to a low-pressure chamber. Literature on the state of the art Patent literature Patent literature 1: JP 2004-197 834 A Further state of the art is disclosed in the following documents. JP 2004-197 834 A The following is disclosed: A pressure pulsation reduction mechanism for reducing pressure pulsation is attached to the upstream side of the pressure relief valve, and the pulsation reduction mechanism consists of a receiving element with a channel and a gap element located in the channel of the receiving element to form a gap flow. The gap for forming the gap flow can be formed between the receiving element and the gap element or on the gap element itself. Furthermore, the pressure pulsation reduction mechanism can include the receiving element with the channel and a shielding element mounted on the receiving element to shield the channel and block the direct flow of fluid. US 2015 / 0 078 922 A1 The following is disclosed: A high-pressure pump comprises a pump body, a pressure chamber, a fuel channel, a connector, a seat, a pressure relief valve seat, a pressure relief valve, an outlet valve seat, an outlet valve, a spring, and a spring retainer. The connector has an internally threaded section and a stepped section formed on an inner wall of the connector. The seat comprises a relief passage extending through the seat in an axial direction and an outlet passage that is not in fluid communication with the relief passage. One opening of the relief passage is closer to the pressure chamber than another opening of the relief passage is to the pressure chamber. One opening of the relief passage is farther from the pressure chamber than another opening of the relief passage is to the pressure chamber. The seat is forced toward the stepped section when the spring retainer is attached to the connector by engaging the internally threaded section with the externally threaded section. Summary Recently, the need for higher fuel pressure in a machine system has led to a need for a higher-pressure fuel supply to an internal combustion engine. To increase the pressure of the fuel being discharged from and supplied to the internal combustion engine by the high-pressure pump, it is effective to reduce the dead volume associated with the pressurization chamber and to create a high-pressure space during pressurization. According to the high-pressure pump described in patent literature 1, a discharge valve is located near the pressurization chamber, while the overflow valve is located on the side opposite the pressurization chamber. This configuration can reduce the dead volume. According to the high-pressure pump described in patent literature 1, the overflow valve is arranged at a position that is radially offset from the axis of the discharge valve, and a pressure pulsation reduction device is provided between the discharge valve and the overflow valve. Furthermore, a flow path through which the discharged fuel flows after passing through the discharge valve is formed radially outside the overflow valve and the pressure pulsation reduction device. Accordingly, the size of the section containing the discharge valve and the overflow valve can be increased. It is an object of the present disclosure to provide a small high-pressure pump. This object is achieved by the high-pressure pump with the features of claim 1. Further advantageous embodiments and developments are the subject of the subsequent claims. A high-pressure pump according to this disclosure comprises a pressurization chamber forming section, a discharge passage forming section, a discharge seat element, an intermediate element, a bypass seat element, a discharge valve, and a bypass valve. The pressurization chamber forming section defines a pressurization chamber in which fuel is pressurized. The discharge passage forming section defines a discharge passage through which the fuel flows that is discharged from the pressurization chamber. The discharge seat element comprises a discharge element body arranged in the discharge passage, a discharge hole passing through the discharge seat element between a surface of the discharge seat element facing the pressurization chamber and a