EP4137694A1

EP4137694A1 - High-pressure fuel supply pump and manufacturing method

Info

Publication number: EP4137694A1
Application number: EP21788498.0A
Authority: EP
Inventors: Akihiro Munakata; Hiroyuki Yamada; Kiyotaka Ogura; Minoru Hashida; Satoshi Usui; Atsuji Saito; Shingo Tamura; Tatsuo Kawano
Original assignee: Hitachi Astemo Ltd
Current assignee: Hitachi Astemo Ltd
Priority date: 2020-04-14
Filing date: 2021-01-29
Publication date: 2023-02-22
Also published as: CN115398090B; WO2021210243A1; CN115398090A; EP4137694A4; JP7295337B2; JPWO2021210243A1

Abstract

Provided is a high-pressure fuel supply pump capable of improving strength of a flange without increasing a plate thickness. A flange 13 includes a step portion 13b1 (first step portion), a step portion 13b2 (second step portion), and a flat portion 13e1 (first flat portion). The step portion 13b1 protrudes in a direction away from a fuel pump attachment portion 90 on an outer periphery of the flange 13. The step portion 13b2 protrudes in a direction away from the fuel pump attachment portion 90 on the outer periphery of the flange 13, and faces the step portion 13b1 with the pump body 1 interposed therebetween. The flat portion 13e1 (first flat portion) is located between the step portion 13b1 and the step portion 13b2, and is flat from the pump body 1 to a first end of the flange 13.

Description

Technical Field

The present invention relates to a high-pressure fuel supply pump and a manufacturing method.

Background Art

A high-pressure fuel supply pump is disclosed in PTL 1, for example. The high-pressure fuel supply pump disclosed in PTL 1 includes an attachment flange for attachment to an engine, and the attachment flange is coupled to a body of the high-pressure fuel supply pump by welding.

Citation List

Patent Literature

PTL 1: JP 2019-15290 A

Summary of Invention

Technical Problem

However, in the high-pressure fuel supply pump disclosed in PTL 1, there is a problem that a maximum generated stress generated in a vicinity of a welded portion of the attachment flange when a discharge pressure is increased becomes equal to or higher than a material strength, and thus the vicinity of the welded portion is damaged. Although it is effective to increase the flexural rigidity by increasing the plate thickness of the attachment flange in order to reduce the maximum generated stress, there are problems of an increase in a weight of the pump as a whole and an increase in a material cost of the attachment flange.
An object of the present invention is to, in consideration of the above problem, provide a high-pressure fuel supply pump capable of improving strength of a flange without increasing a plate thickness.

Solution to Problem

In order to achieve the above object, one example of the present invention is a high-pressure fuel supply pump including a pump body, and a flange provided radially outward from the pump body and attached to a separate component, in which the flange includes a first step portion that protrudes in a direction away from the separate component on an outer periphery of the flange, a second step portion that protrudes in a direction away from the separate component on the outer periphery of the flange and faces the first step portion with the pump body interposed therebetween, and a first flat portion that is located between the first step portion and the second step portion and is flat from the pump body to a first end of the flange.

Advantageous Effects of Invention

The present invention can improve the strength of the flange without increasing the plate thickness. Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

Brief Description of Drawings

[FIG. 1] FIG. 1 is an overall configuration diagram of a fuel supply system using a high-pressure fuel supply pump according to one embodiment of the present invention.
[FIG. 2] FIG. 2 is a longitudinal sectional view (part 1) of the high-pressure fuel supply pump according to one embodiment of the present invention.
[FIG. 3] FIG. 3 is a longitudinal sectional view (part 2) of the high-pressure fuel supply pump according to one embodiment of the present invention.
[FIG. 4] FIG. 4 is a horizontal sectional view of the high-pressure fuel supply pump according to one embodiment of the present invention as viewed from above.
[FIG. 5] FIG. 5 is an external view of an attachment flange in the high-pressure fuel supply pump according to one embodiment of the present invention.
[FIG. 6] FIG. 6 illustrates an A-A cross section of the attachment flange in the high-pressure fuel supply pump according to one embodiment of the present invention.
[FIG. 7] FIG. 7 illustrates a B-B cross section of the attachment flange in the high-pressure fuel supply pump according to one embodiment of the present invention.

Description of Embodiments

Hereinafter, a high-pressure fuel supply pump according to one embodiment of the present invention will be described. In the drawings, the same members are denoted by the same reference signs. An object of the present embodiment is to improve an insufficient strength, for example, by reducing a maximum generated stress in a vicinity of a welded portion of an attachment flange without increasing a plate thickness of the attachment flange when a discharge pressure is increased.

[Fuel supply system]

A fuel supply system using the high-pressure fuel supply pump according to the present embodiment will be described with reference to FIG. 1. FIG. 1 is an overall configuration diagram of the fuel supply system using the high-pressure fuel supply pump according to the present embodiment of the present invention.
As illustrated in FIG. 1, the fuel supply system includes a high-pressure fuel supply pump 100, an engine control unit (ECU) 101, a fuel tank 103, a common rail 106, and a plurality of injectors 107. Components of the high-pressure fuel supply pump 100 are integrally incorporated in a pump body 1 (body).
Fuel in the fuel tank 103 is pumped up by a feed pump 102 that is driven in response to a signal from the ECU 101. The pumped fuel is pressurized to an appropriate pressure by a pressure regulator (not illustrated) and sent to a low-pressure fuel suction port 51 of the high-pressure fuel supply pump 100 through a low-pressure pipe 104.
The high-pressure fuel supply pump 100 pressurizes the fuel supplied from the fuel tank 103 and pressure-feeds the fuel to the common rail 106. The plurality of injectors 107 and a fuel pressure sensor 105 are mounted on the common rail 106. The plurality of injectors 107 is mounted in accordance with the number of cylinders (combustion chambers), and injects fuel in accordance with a drive current output from the ECU 101. The fuel supply system according to the present embodiment is a so-called direct injection engine system in which the injector 107 directly injects fuel into a cylinder of the engine.
The fuel pressure sensor 105 outputs detected pressure data to the ECU 101. The ECU 101 calculates an appropriate injection fuel amount (target injection fuel amount), an appropriate fuel pressure (target fuel pressure), and the like on the basis of engine state quantities (for example, a crank rotation angle, a throttle opening, an engine speed, a fuel pressure, and the like) obtained from various sensors.
The ECU 101 controls driving of the high-pressure fuel supply pump 100 and the plurality of injectors 107 on the basis of a calculation result of the fuel pressure (target fuel pressure) and the like. That is, the ECU 101 includes a pump controller that controls the high-pressure fuel supply pump 100 and an injector controller that controls the injectors 107.
The high-pressure fuel supply pump 100 includes a pressure pulsation reduction mechanism 9, an electromagnetic suction valve 3 which is a variable capacity mechanism, a relief valve mechanism 4 (see FIG. 3), and a discharge valve 8. The fuel flowing from the low-pressure fuel suction port 51 reaches a suction port 335a of the electromagnetic suction valve 3 via the pressure pulsation reduction mechanism 9 and a suction passage 10b.
The fuel flowing into the electromagnetic suction valve 3 passes through a valve portion 339, flows through a suction passage 1a provided in the pump body 1, and then flows into a pressurizing chamber 11. A plunger 2 is slidably held in the pressurizing chamber 11. The plunger 2 reciprocates when power is transmitted by a cam 91 (see FIG. 2) of the engine.
In the pressurizing chamber 11, fuel is sucked from the electromagnetic suction valve 3 in a downward stroke of the plunger 2, and the fuel is pressurized in an upward stroke. When the fuel pressure in the pressurizing chamber 11 exceeds a set value, the discharge valve 8 is opened, and the high-pressure fuel is pressure-fed to the common rail 106 through a discharge passage 12a. The fuel discharge by the high-pressure fuel supply pump 100 is operated by opening and closing the electromagnetic suction valve 3. The opening and closing of the electromagnetic suction valve 3 is controlled by the ECU 101.

[High-pressure fuel supply pump]

Next, a configuration of the high-pressure fuel supply pump 100 will be described with reference to FIGS. 2 to 4.
FIG. 2 is a longitudinal sectional view (part 1) of the high-pressure fuel supply pump 100 as viewed in a cross section orthogonal to a horizontal direction, and FIG. 3 is a longitudinal sectional view (part 2) of the high-pressure fuel supply pump 100 as viewed in a cross section orthogonal to the horizontal direction.
FIG. 4 is a horizontal sectional view of the high-pressure fuel supply pump 100 as viewed in a cross section orthogonal to a perpendicular direction.
As illustrated in FIGS. 2 to 4, the pump body 1 of the high-pressure fuel supply pump 100 is provided with the suction passage 1a described above and a flange 13 (attachment flange). The flange 13 is in close contact with a fuel pump attachment portion 90 of an engine (internal combustion engine) and is fixed with a plurality of bolts (screws) (not illustrated). That is, the high-pressure fuel supply pump 100 is fixed to the fuel pump attachment portion 90 by the flange 13.
As illustrated in FIG. 2, an O-ring 93 illustrating a specific example of a seat member is interposed between the fuel pump attachment portion 90 and the pump body 1. The O-ring 93 prevents engine oil from leaking to outside of the engine (internal combustion engine) through between the fuel pump attachment portion 90 and the pump body 1.
A cylinder 6 that guides reciprocating motion of the plunger 2 is attached to the pump body 1 of the high-pressure fuel supply pump 100. The cylinder 6 has a tubular shape, and is press-fitted into the pump body 1 on an outer periphery of the cylinder 6. The pump body 1 and the cylinder 6 form the pressurizing chamber 11 together with the electromagnetic suction valve 3, the plunger 2, and the discharge valve 8 (see FIG. 4).
The pump body 1 is provided with a fixing portion 1e that engages with a central portion in an axial direction of the cylinder 6. The fixing portion 1e of the pump body 1 presses the cylinder 6 upward (upward in FIG. 2) so that the fuel pressurized in the pressurizing chamber 11 does not leak from between an upper end surface of the cylinder 6 and the pump body 1.
A lower end of the plunger 2 is provided with a tappet 92 that converts rotational motion of the cam 91 attached to a cam shaft of the engine into vertical motion and transmits the vertical motion to the plunger 2. The plunger 2 is biased toward the cam 91 by a spring 16 via a retainer 15, and is pressed against the tappet 92. The tappet 92 reciprocates with rotation of the cam 91. The plunger 2 reciprocates together with the tappet 92 to change a volume of the pressurizing chamber 11.
A seal holder 17 is disposed between the cylinder 6 and the retainer 15. The seal holder 17 has a tubular shape into which the plunger 2 is inserted, and has an auxiliary chamber 17a at an upper end close to the cylinder 6. The seal holder 17 holds a plunger seal 18 at a lower end close to the retainer 15.
The plunger seal 18 is slidably in contact with an outer periphery of the plunger 2, and seals the fuel in the auxiliary chamber 17a when the plunger 2 reciprocates to prevent the fuel in the auxiliary chamber 17a from flowing into the engine. The plunger seal 18 prevents lubricating oil (including engine oil) that lubricates a sliding portion of the engine from flowing into the pump body 1.
In FIG. 2, the plunger 2 reciprocates up and down. When the plunger 2 descends, the volume of the pressurizing chamber 11 increases, and when the plunger 2 rises, the volume of the pressurizing chamber 11 decreases. That is, the plunger 2 is disposed so as to reciprocate in a direction of enlarging and reducing the volume of the pressurizing chamber 11.
The plunger 2 has a large diameter portion 2a and a small diameter portion 2b. When the plunger 2 reciprocates, the large diameter portion 2a and the small diameter portion 2b are located in the auxiliary chamber 17a. Therefore, the volume of the auxiliary chamber 17a increases or decreases by the reciprocation of the plunger 2.
The auxiliary chamber 17a communicates with a low-pressure fuel chamber 10 through a fuel passage 10c (see FIG. 4). When the plunger 2 descends, fuel flows from the auxiliary chamber 17a to the low-pressure fuel chamber 10, and when the plunger 2 rises, fuel flows from the low-pressure fuel chamber 10 to the auxiliary chamber 17a. As a result, a flow rate of fuel flowing into and out of the pump in a suction stroke or a return stroke of the high-pressure fuel supply pump 100 can be reduced, and pressure pulsation generated in the high-pressure fuel supply pump 100 can be reduced.
The pump body 1 is provided with the relief valve mechanism 4 communicating with the pressurizing chamber 11. The relief valve mechanism 4 is a valve configured to operate and return the fuel in the discharge passage 12a to the pressurizing chamber 11 when some problem occurs in the common rail 106 or a member beyond the common rail 106 and the common rail becomes a high pressure exceeding a predetermined pressure.
The relief valve mechanism 4 includes a relief spring 41, a relief valve holder 42, a relief valve 43, and a seat member 44. One end of the relief spring 41 abuts on the pump body 1, and the other end abuts on the relief valve holder 42. The relief valve holder 42 engages with the relief valve 43, and a biasing force of the relief spring 41 acts on the relief valve 43 via the relief valve holder 42.
The relief valve 43 is pressed by the biasing force of the relief spring 41 to close a fuel passage of the seat member 44. The fuel passage of the seat member 44 communicates with the discharge passage 12a. Movement of fuel between the pressurizing chamber 11 (upstream side) and the seat member 44 (downstream side) is blocked by contact (close contact) of the relief valve 43 with the seat member 44.
When a pressure in the common rail 106 or a member beyond the common rail increases, the fuel close to the seat member 44 presses the relief valve 43 to move the relief valve 43 against the biasing force of the relief spring 41. As a result, the relief valve 43 is opened, and the fuel in the discharge passage 12a returns to the pressurizing chamber 11 through the fuel passage of the seat member 44. Therefore, a pressure for opening the relief valve 43 is determined by the biasing force of the relief spring 41.
The relief valve mechanism 4 according to the present embodiment communicates with the pressurizing chamber 11, but is not limited thereto. For example, the relief valve mechanism 4 may communicate with a low-pressure passage (the low-pressure fuel suction port 51, the suction passage 10b, or the like).
As illustrated in FIG. 2, the pump body 1 of the high-pressure fuel supply pump 100 is provided with the low-pressure fuel chamber 10. A suction joint 5 is attached to a side surface of the low-pressure fuel chamber 10. The suction joint 5 is connected to the low-pressure pipe 104 through which the fuel supplied from the fuel tank 103 passes. The fuel in the fuel tank 103 is supplied from the suction joint 5 into the high-pressure fuel supply pump 100.
The suction joint 5 includes the low-pressure fuel suction port 51 connected to the low-pressure pipe 104 and a suction flow path 52 communicating with the low-pressure fuel suction port 51. The fuel that has passed through the suction flow path 52 reaches the suction port 335a (see FIG. 3) of the electromagnetic suction valve 3 via the pressure pulsation reduction mechanism 9 and the suction passage 10b (see FIG. 3) provided in the low-pressure fuel chamber 10. A suction filter 53 is disposed in the suction flow path 52. The suction filter 53 removes foreign substances present in the fuel and prevents foreign substances from entering the high-pressure fuel supply pump 100.
The low-pressure fuel chamber 10 is provided with a low-pressure fuel flow path 10a and a suction passage 10b. The suction passage 10b communicates with the suction port 335a (see FIG. 3) of the electromagnetic suction valve 3, and the fuel passing through the low-pressure fuel flow path 10a reaches the suction port 335a of the electromagnetic suction valve 3 via the suction passage 10b.
The low-pressure fuel flow path 10a is provided with the pressure pulsation reduction mechanism 9. When the fuel flowing into the pressurizing chamber 11 is returned to the suction passage 10b (see FIG. 3) through the electromagnetic suction valve 3 in a valve open state again, pressure pulsation occurs in the low-pressure fuel chamber 10. The pressure pulsation reduction mechanism 9 reduces spreading of the pressure pulsation generated in the high-pressure fuel supply pump 100 to the low-pressure pipe 104.
The pressure pulsation reduction mechanism 9 is formed of a metal diaphragm damper in which two corrugated disk-shaped metal plates are bonded to each other at an outer periphery of the metal plates, and an inert gas such as argon is injected into the metal diaphragm damper. The metal diaphragm damper of the pressure pulsation reduction mechanism 9 expands and contracts to absorb or reduce pressure pulsation.
The discharge valve 8 is connected to an outlet of the pressurizing chamber 11. As illustrated in FIG. 4, the discharge valve 8 includes a discharge valve seat 81 communicating with the pressurizing chamber 11, a valve body 82 that comes into contact with and separates from the discharge valve seat 81, a discharge valve spring 83 that biases the valve body 82 toward the discharge valve seat 81, and a discharge valve stopper 84 that determines a stroke (moving distance) of the valve body 82.
The discharge valve 8 includes a plug 85 that blocks leakage of fuel to the outside. The discharge valve stopper 84 is press-fitted into the plug 85. The plug 85 is joined to the pump body 1 by welding at a welded portion 86. The discharge valve 8 communicates with a discharge valve chamber 87 opened and closed by the valve body 82. The discharge valve chamber 87 is provided in the pump body 1 and communicates with a fuel discharge port 12b via a lateral hole provided in the pump body 1 and extending in the horizontal direction.
A discharge joint 12 is inserted into the lateral hole provided in the pump body 1. The discharge joint 12 includes the discharge passage 12a communicating with the lateral hole and the fuel discharge port 12b which is one end of the discharge passage 12a. The fuel discharge port 12b of the discharge joint 12 communicates with the common rail 106. The discharge joint 12 is fixed to the pump body 1 by welding by a welded portion 12c.
In a state where there is no difference in fuel pressure (fuel differential pressure) between the pressurizing chamber 11 and the discharge valve chamber 87, the valve body 82 is pressed against the discharge valve seat 81 by a biasing force of the discharge valve spring 83, and the discharge valve 8 is closed. When the fuel pressure in the pressurizing chamber 11 becomes larger than the fuel pressure in the discharge valve chamber 87, the valve body 82 moves against the biasing force of the discharge valve spring 83, and the discharge valve 8 is opened.
When the discharge valve 8 is closed, the (high-pressure) fuel in the pressurizing chamber 11 passes through the discharge valve 8 and reaches the discharge valve chamber 87. Then, the fuel that has reached the discharge valve chamber 87 is discharged to the common rail 106 (see FIG. 1) through the fuel discharge port 12b of the discharge joint 12. In such a configuration, the discharge valve 8 functions as a check valve that restricts a flowing direction of the fuel.

[Structure of flange]

Hereinafter, the present embodiment will be specifically described with reference to FIGS. 5 to 7. FIGS. 5 to 7 illustrate a shape of the flange 13 according to the present embodiment.
The high-pressure fuel supply pump 100 of the present embodiment includes the flange 13 welded and fixed to the pump body 1 on an outer peripheral surface 1d (see FIG. 2) of the pump body 1. The flange 13 has an annular flat portion 13a in close contact with the fuel pump attachment portion 90, and step portions 13b1 and 13b2 pushed out to the opposite side of the attachment surface 90a are provided on an outer periphery of the flange 13 so as to face each other with the pump as the center.
In other words, the high-pressure fuel supply pump 100 includes the pump body 1 and the flange 13 provided radially outward from the pump body 1 and attached to the fuel pump attachment portion 90 (separate component). The flange 13 includes at least the step portion 13b1 (first step portion), the step portion 13b2 (second step portion), and a flat portion 13e1 (first flat portion).
As illustrated in FIG. 6, the step portion 13b1 (first step portion) protrudes in a direction away from the fuel pump attachment portion 90 (separate component) on the outer periphery of the flange 13. The step portion 13b2 (second step portion) protrudes in a direction away from the fuel pump attachment portion 90 (separate component) on the outer periphery of the flange 13, and faces the step portion 13b1 (first step portion) with the pump body 1 interposed therebetween. The flat portion 13e1 (first flat portion) is located between the step portion 13b1 (first step portion) and the step portion 13b2 (second step portion), and is flat from the pump body 1 to a first end of the flange 13.
A strength of the flange 13 can be improved by the step portion 13b1 (first step portion) and the step portion 13b2 (second step portion). The flat portion 13e1 (first flat portion) can prevent liquid such as water from accumulating.
The step portions 13b1 and 13b2 are provided only in a longitudinal direction of the flange 13 and are not provided in a transverse direction of the flange 13. In other words, the step portion 13b1 (first step portion) and the step portion 13b2 (second step portion) are provided only on the outer periphery along the longitudinal direction of the flange 13. Thus, for example, a material cost can be reduced.
In the present embodiment, the flange 13 is disposed at a position facing the flat portion 13e1 (first flat portion) with the pump body 1 interposed therebetween, and includes a flat portion 13e2 (second flat portion) that is flat from the pump body 1 to a second end of the flange 13. The flat portion 13e1 (first flat portion) and the flat portion 13e2 (second flat portion) are connected to a side surface of the flange 13 to form an edge 13g along the transverse direction of the flange 13. This configuration facilitates discharge of liquid such as water. A periphery of the edge 13g is fixed with a bolt to sufficiently secure the strength.
Such a configuration can reduce a maximum stress generated in the vicinity of the welded portion of the flange 13 of the high-pressure fuel supply pump 100 without increasing a plate thickness T (see FIG. 6).
A reaction force of fuel compression acts on the high-pressure fuel supply pump 100 in a direction opposite to the attachment surface 90a (pump attachment surface), and the force is a product of an in-cylinder pressure and a diameter area of the plunger 2. Therefore, as the discharge pressure increases, the reaction force also increases proportionally.
The flange 13 is connected to the outer periphery of the pump body 1 by welding in order to fix and hold the pump. In order to suppress the increase in the maximum stress generated in the vicinity of the welded portion with the increase in the reaction force of fuel compression due to the increase in the discharge pressure to the high fuel pressure, it is common to increase the plate thickness T of the flange 13. However, the above configuration can reduce the maximum generated stress without increasing the plate thickness T.
As illustrated in FIG. 5, the flange 13 has two attachment bolt insertion holes 13c (bolt insertion holes) facing each other with the pump body 1 as the center, and an outer periphery of the attachment bolt insertion holes 13c is fixed with attachment bolts, only two parts of the flange 13 between the attachment bolts are deformed by receiving the reaction force of fuel compression. Therefore, in order to increase a flexural rigidity, the step portions 13b1 and 13b2 only need to be provided between the two bolt insertion holes 13c on the outer periphery in the longitudinal direction of the flange 13, and are unnecessary in the transverse direction.
In other words, each of the flat portion 13e1 (first flat portion) and the flat portion 13e2 (second flat portion) is provided with the bolt insertion hole 13c which is a hole for inserting a bolt. The bolt insertion hole 13c of the flat portion 13e1 (first flat portion) and the bolt insertion hole 13c of the flat portion 13e2 (second flat portion) are disposed at radially symmetrical positions along one axis that passes through a central axis of a pump body insertion hole 13f.
As illustrated in FIGS. 5 and 6, by providing an annular step 13d on an outer periphery of a welded portion of the pump body 1, the maximum generated stress can be further reduced.
In other words, the flange 13 has the pump body insertion hole 13f as a hole through which the pump body 1 is inserted, and the flange 13 has the annular step 13d (annular step portion) around the pump body insertion hole 13f.
In the present embodiment, a surface of the annular step 13d (annular step portion) opposite to the fuel pump attachment portion 90 (separate component) protrudes from the flat portion 13e1 (first flat portion) and the flat portion 13e2 (second flat portion) in a direction away from the fuel pump attachment portion 90 (separate component) by a gap g1 between the annular step 13d (annular step portion) and the fuel pump attachment portion 90 (separate component). Thus, the plate thickness T is secured at the annular step 13d (annular step portion).
The flange 13 includes the annular flat portion 13a in contact with the fuel pump attachment portion 90 (separate component). Accordingly, the annular flat portion 13a is in close contact with the fuel pump attachment portion 90 (separate component). The annular step 13d (annular step portion) opposite to the fuel pump attachment portion 90 (separate component) is provided with a taper 13h that comes closer to the fuel pump attachment portion 90 (separate component) toward the pump body 1. This configuration facilitates dimensioning.
The annular step 13d (annular step portion) opposite to the fuel pump attachment portion 90 (separate component) is raised in an R shape from the flat portion 13e1 (first flat portion) and the flat portion 13e2 (second flat portion). As a result, the maximum generated stress in the vicinity of the welded portion of the flange 13 can be reduced.
A length in the transverse direction of the flat portion 13e1 (first flat portion) and the flat portion 13e2 (second flat portion) is larger than a diameter of a seat 13k of the bolt. Thus, a flow path for discharging liquid such as water is formed between a head of the bolt and the step portion 13b1 (first step portion) or the step portion 13b1.
The length in the transverse direction of the flat portion 13e1 (first flat portion) and the flat portion 13e2 (second flat portion) is smaller than a diameter of the pump body insertion hole 13f. Thus, for example, a material cost can be reduced. The step portion 13b1 (first step portion) and the step portion 13b2 (second step portion) opposite to the fuel pump attachment portion 90 (separate component) are raised in an R shape from the flat portion 13e1 (first flat portion) and the flat portion 13e2 (second flat portion). As a result, the maximum generated stress in the vicinity of the welded portion of the flange 13 can be further reduced.
In the present embodiment, the step portion 13b1 (first step portion) and the step portion 13b2 (second step portion) are formed by press working, for example. Thus, the flange 13 can be easily formed.
As described above, the present embodiment can improve the strength of the flange 13 without increasing the plate thickness.
The present invention is not limited to the above embodiments, but includes various modifications. For example, the above embodiments have been described in detail to make the description of the present invention easy to understand, and the present invention does not necessarily include all the above-described configurations. A part of the configuration of one embodiment can be replaced with a configuration of another embodiment, and the configuration of one embodiment can be added to a configuration of another embodiment. It is possible to add, delete, and replace another configuration for a part of the configuration of each embodiment.
The embodiments of the present invention may have the following aspects.

(1). A high-pressure fuel pump includes a flange provided on an outer diameter from an outer periphery of a pump body of a pump, configured to be attached to a separate component, and including a surface disposed opposite to an attachment surface, a first step portion protruding from the surface to a side opposite to the attachment surface on an outer periphery of the surface, a second step portion protruding from the surface to the side opposite to the attachment surface on the outer periphery of the surface and located opposite to the first step portion in a planar direction, and a first flat portion located between the first step portion and the second step portion in the planar direction and provided up to an end of the outer periphery the surface at substantially an identical height to the surface.
(2). In the high-pressure fuel pump, the first step portion and the second step portion each include a flange provided in a longitudinal direction of the flange.
(3). The high-pressure fuel pump includes the flange including a second flat portion located opposite to the first flat portion in the planar direction.
(4). In the high-pressure fuel pump, the first flat portion and the second flat portion each include a flange provided in a transverse direction of the flange.
(5). In the high-pressure fuel pump, a rear surface of the flange is provided with an annular flat portion that abuts on a fixing member, and an annular step portion that expands radially is provided between the annular flat portion and a welded portion.
(6). In the high-pressure fuel pump, a part of the annular flat portion has a pair of attachment bolt insertion holes at radially symmetrical positions along one axis that passes through a central axis of an insertion hole.
(7). In the high-pressure fuel pump, an upper end of each of the pump body insertion holes protrudes upward by an amount corresponding to a step from an upper end of each of the attachment bolt insertion holes.

That is, the high-pressure fuel supply pump is provided with a step portion pushed out to the opposite side of the attachment surface on both sides on the outer periphery in the longitudinal direction, facing each other with the pump body of the attachment flange as the center. As a result, the flexural rigidity of the attachment flange is improved, and a stress at a stress concentration part can be reduced. Therefore, the maximum generated stress in the vicinity of the welded portion of the attachment flange can be reduced without increasing the plate thickness of the attachment flange, and a safety factor of the welded portion can be improved.

Reference Signs List

1: body (pump body)
13: flange (attachment flange)
13a: annular flat portion
13b1: step portion
13b2: step portion
13c: bolt insertion hole
13d: annular step
13e1: flat portion
13e2: flat portion
13f: pump body insertion hole
13g: edge
13h: taper
13k: seat
100: high-pressure fuel supply pump

Claims

A high-pressure fuel supply pump comprising:
a pump body; and

a flange provided radially outward from the pump body and attached to a separate component,

wherein the flange includes

a first step portion that protrudes in a direction away from the separate component on an outer periphery of the flange,

a second step portion that protrudes in a direction away from the separate component on the outer periphery of the flange and faces the first step portion with the pump body interposed therebetween, and

a first flat portion that is located between the first step portion and the second step portion and is flat from the pump body to a first end of the flange.
The high-pressure fuel supply pump according to claim 1, wherein the first step portion and the second step portion are provided only on the outer periphery along a longitudinal direction of the flange.
The high-pressure fuel supply pump according to claim 2, wherein the flange includes a second flat portion that is disposed at a position facing the first flat portion with the pump body interposed therebetween and is flat from the pump body to a second end of the flange.
The high-pressure fuel supply pump according to claim 3, wherein the first flat portion and the second flat portion are connected to a side surface of the flange and are provided with an edge along a transverse direction of the flange.
The high-pressure fuel supply pump according to claim 4, wherein
the flange includes a pump body insertion hole that is a hole through which the pump body is inserted, and

the flange includes an annular step portion around the pump body insertion hole.
The high-pressure fuel supply pump according to claim 5, wherein each of the first flat portion and the second flat portion includes a bolt insertion hole that is a hole through which a bolt is inserted.
The high-pressure fuel supply pump according to claim 5, wherein the annular step portion has a surface opposite to the separate component, the surface protruding from the first flat portion and the second flat portion in a direction away from the separate component by a gap between the annular step portion and the separate component.
The high-pressure fuel supply pump according to claim 6, wherein the bolt insertion hole of the first flat portion and the bolt insertion hole of the second flat portion are disposed at radially symmetrical positions along one axis that passes through a central axis of the pump body insertion hole.
The high-pressure fuel supply pump according to claim 5, wherein the flange includes an annular flat portion in contact with the separate component.
The high-pressure fuel supply pump according to claim 5, wherein the annular step portion opposite to the separate component includes a taper that approaches the separate component toward the pump body.
The high-pressure fuel supply pump according to claim 5, wherein the annular step portion opposite to the separate component is raised in an R shape from the first flat portion and the second flat portion.
The high-pressure fuel supply pump according to claim 6, wherein each of the first flat portion and the second flat portion has a length in a transverse direction, the length being larger than a diameter of a seat of the bolt.
The high-pressure fuel supply pump according to claim 12, wherein each of the first flat portion and the second flat portion has the length in the transverse direction, the length being smaller than a diameter of the pump body insertion hole.
The high-pressure fuel supply pump according to claim 3, wherein the first step portion and the second step portion opposite to the separate component are raised in an R shape from the first flat portion and the second flat portion.
A manufacturing method for the flange used in the high-pressure fuel supply pump according to claim 1, the method comprising forming the first step portion and the second step portion by press working.