WO2020195222A1

WO2020195222A1 - Fuel pump

Info

Publication number: WO2020195222A1
Application number: PCT/JP2020/004726
Authority: WO
Inventors: 徳尾　健一郎; 山田　裕之; 清隆小倉; 真悟田村
Original assignee: 日立オートモティブシステムズ株式会社
Priority date: 2019-03-28
Filing date: 2020-02-07
Publication date: 2020-10-01
Also published as: JP7055933B2; DE112020000678T5; CN113574267A; CN113574267B; JPWO2020195222A1

Abstract

The purpose of the present invention is to provide a fuel pump provided with a structure that enables fixing of the positions of a damper cover and a body. Thus, the fuel pump according to the present invention is provided with: a body 1; a cover part 20 which covers the body 1; a support member 22 which supports a housed part (damper 9); a first press-fit part 20a which is formed between the support member 22 and the cover part 20 and which fixes the support member 22 to the cover part 20; and a second press-fit part 1a which is formed between the support member 22 and the body 1 and which fixes the support member 22 to the body 1, the second press-fit part 1a being formed in the same surface, of the support member 22, as the first press-fit part 20a is.

Description

Fuel pump

The present invention relates to a fuel pump particularly suitable for use as a vehicle component, and relates to a fuel pump that supplies fuel to an engine at high pressure.

As a background technique of the present invention, a high-pressure pump described in Japanese Patent Application Laid-Open No. 2012-154304 (Patent Document 1) is known. In this high-pressure pump, the outer wall of the damper cylinder portion provided on the damper member and the inner wall of the cover cylinder portion provided on the cover member are welded over the entire circumference, so that between the damper member and the cover member. It forms a sealed damper chamber (paragraph 0025).
This high-pressure pump further includes a cylindrical tubular member, and the outer wall of the tubular portion provided on the tubular member is in contact with the welded portion of the inner wall of the damper tubular portion with the cover tubular portion (paragraph 0045). Further, in the high-pressure pump of Patent Document 1, the outer wall of the extended tubular portion provided on the tubular member abuts on the side wall of the concave portion provided on the housing (paragraph 0046), and the back side of the abutting portion between the cover member and the housing is the tubular portion. The member covers it (Fig. 4). With such a configuration, in the high-pressure pump of Patent Document 1, the tubular portion of the tubular member suppresses the radial inward deformation of the welded portion of the damper tubular portion with the cover tubular portion, and the welded state of the welded portion is maintained. It is kept stable (paragraph 0048).

Japanese Unexamined Patent Publication No. 2012-154304

Although not described in Patent Document 1, in a high-pressure fuel supply pump (fuel pump), the damper cover and the body are welded at abutment portion provided between a cover member (damper cover) and a housing (body). Will be done. In this case, in the high-pressure fuel supply pump of Patent Document 1, when the damper cover and the body are welded, the tubular member that covers the back side of the welded portion between the damper cover and the body is replaced with the damper cover (cover member) and the body (housing). On the other hand, although the contact is made on the back side of the abutting portion, no consideration is given to fixing the damper cover and the body with a tubular member in the abutting direction between the damper cover and the body.

When welding the damper cover and the body, the position of the welded portion shifts between the damper cover and the body in the abutting direction due to expansion during melting and contraction during solidification. Therefore, in order to prevent the displacement between the damper cover and the body, a means for fixing the position between the damper cover and the body is required at the time of welding the damper cover and the body. Hereinafter, the damper cover will be described as a cover portion.

An object of the present invention is to provide a fuel pump having a structure capable of fixing the positions of a cover portion and a body.

In order to achieve the above object, the fuel pump of the present invention
With the body
A cover portion that covers the body and
Support members that support the accommodation part and
A first press-fitting portion formed between the support member and the cover portion and fixing the support member to the cover portion,
A second press-fitting portion formed between the support member and the body, formed on the same surface as the surface on which the first press-fitting portion of the support member is formed, and fixing the support member to the body. Be prepared.

According to the present invention, it is possible to provide a fuel pump having a structure capable of fixing the positions of the cover portion and the body. Issues, configurations and effects other than those described above will be clarified by the description of the following embodiments.

It is a conceptual diagram which shows the structure of the engine system to which the high pressure fuel supply pump which concerns on one Example of this invention is applied. It is sectional drawing which shows the cross section parallel to the axial direction of the plunger 2 of the high pressure fuel supply pump which concerns on one Example of this invention. FIG. 3 is a cross-sectional view showing a cross section perpendicular to the axial direction of the plunger 2 as viewed from above the high-pressure fuel supply pump of FIG. It is sectional drawing which shows the cross section around the damper cover of FIG. It is sectional drawing which shows the cross section of the damper cover subassembly before body assembly.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

First, the high-pressure fuel supply pump 100 according to an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a conceptual diagram showing a configuration of an engine system to which a high-pressure fuel supply pump according to an embodiment of the present invention is applied. Although the vertical direction may be specified in the following description, this vertical direction is based on the vertical direction of FIG. 1, and does not necessarily match the vertical direction in the mounted state of the high-pressure fuel supply pump 100.

The part surrounded by the broken line shows the main body of the high-pressure fuel supply pump (hereinafter referred to as a fuel pump) 100, and the mechanism and parts shown in the broken line are integrated with the body 1 (may be called a pump body). It is built into.

The fuel in the fuel tank 103 is pumped from the fuel tank 103 by the feed pump 102 based on a signal from the engine control unit 101 (hereinafter referred to as an ECU). This fuel is pressurized to an appropriate feed pressure and sent to the low pressure fuel suction port 10a of the fuel pump through the fuel pipe 104. The low pressure fuel suction port 10a is provided in the suction pipe 5 (see FIGS. 2 and 5).

The fuel flowing in from the low-pressure fuel suction port 10a reaches the suction port 3k of the electromagnetic suction valve mechanism 3 which is a capacity variable mechanism via the damper (damper mechanism) 9 which is a pressure pulsation reduction mechanism and the suction passage 10d.

The fuel that has flowed into the electromagnetic suction valve mechanism 3 passes through the suction valve 3b, flows through the suction passage 1a formed in the body 1, and then flows into the pressurizing chamber 11. The cam mechanism 91 of the engine (see FIG. 2) gives the plunger 2 reciprocating power. Due to the reciprocating motion of the plunger 2, fuel is sucked from the suction valve 3b in the descending stroke of the plunger 2, and the fuel is pressurized in the ascending stroke.

When the pressure in the pressurizing chamber 11 exceeds the set value, the discharge valve mechanism 8 opens, and the pressure sensor 105 is mounted on the common rail 106 through the fuel discharge port 12a provided in the discharge joint 12 (see FIG. 2). High-pressure fuel is pumped to. Then, the injector 107 injects fuel into the engine based on the signal from the ECU 101. The fuel pump 100 of this embodiment is a fuel pump applied to a so-called direct injection engine system in which the injector 107 injects fuel directly into the cylinder cylinder of the engine. The fuel pump 100 discharges a desired flow rate of fuel by a signal from the ECU 101 to the electromagnetic suction valve mechanism 3.

FIG. 2 is a cross-sectional view showing a cross section parallel to the axial direction of the plunger 2 of the high-pressure fuel supply pump according to the embodiment of the present invention. FIG. 3 is a cross-sectional view showing a cross section perpendicular to the axial direction of the plunger 2 as viewed from above the high-pressure fuel supply pump of FIG.

The fuel pump 100 uses the mounting flange 1e provided on the body 1 and is fixed to the fuel pump mounting portion 90 of the engine (internal combustion engine) with a plurality of bolts.

As shown in FIG. 2, a cylinder 6 that guides the reciprocating motion of the plunger 2 and forms a pressurizing chamber 11 together with the body 1 is attached to the body 1. Further, the body 1 is provided with an electromagnetic suction valve mechanism 3 for supplying fuel to the pressurizing chamber 11 and a discharge valve mechanism 8 for discharging fuel from the pressurizing chamber 11 to the discharge passage.

The cylinder 6 is press-fitted with the body 1 on the outer peripheral side thereof. The pressurizing chamber 11 is composed of a body 1, an electromagnetic suction valve mechanism 3, a plunger 2, a cylinder 6, and a discharge valve mechanism 8.

At the lower end of the plunger 2, a tappet 92 is provided that converts the rotational motion of the cam 91 attached to the camshaft of the engine into a vertical motion and transmits it to the plunger 2. The plunger 2 is crimped to the tappet 92 by a spring 18 via a retainer 15. As a result, the plunger 2 can be reciprocated up and down with the rotational movement of the cam 91.

Further, the plunger seal 13 held at the lower end of the inner circumference of the seal holder 7 is installed in a slidable contact with the outer periphery of the plunger 2 at the lower portion in the drawing of the cylinder 6. As a result, when the plunger 2 slides, the fuel in the sub chamber 7a is sealed and prevented from flowing into the engine. At the same time, it prevents the lubricating oil (including the engine oil) that lubricates the sliding portion in the engine from flowing into the body 1.

The relief valve mechanism 4 shown in FIGS. 2 and 3 is composed of a seat member 4e, a relief valve 4d, a relief valve holder 4c, a relief spring 4b, and a spring support member 4a. In the relief valve 4d, the urging force of the relief spring 4b acts via the relief valve holder 4c and is pressed against the seat member 4e to shut off the fuel. The relief valve mechanism 4 is configured so that when the differential pressure between the upstream side and the downstream side of the relief valve 4d exceeds the set pressure, the relief valve 4d opens against the urging force of the relief spring 4b. ..

In this embodiment, the relief valve mechanism 4 communicates with the pressurizing chamber 11 via the relief passage, but is not limited to this, and communicates with the low pressure passage (low pressure fuel chamber 10 or suction passage 10d, etc.). You may try to do it. The relief valve mechanism 4 is a valve configured to operate when a problem occurs in the common rail 106 or a member beyond the common rail 106 and the common rail 106 becomes abnormally high pressure.

There is a damper cover 20 forming a low pressure fuel chamber 10 on the upper part of the fuel pump 100, and a suction pipe 5 is attached to the side surface portion thereof. The suction pipe 5 is connected to a low pressure pipe 104 that supplies fuel from the fuel tank 103 of the vehicle, and the fuel is supplied to the inside of the fuel pump 100 from the low pressure fuel suction port 10a of the suction pipe 5. The fuel that has passed through the suction pipe 5 reaches the suction port 3k of the electromagnetic suction valve mechanism 3 via the damper 9 which is a pressure pulsation reduction mechanism and the low pressure fuel flow path 10d.

When the plunger 2 moves in the direction of the cam 91 (downward) and is in the suction stroke, the volume of the pressurizing chamber 11 increases and the fuel pressure in the pressurizing chamber 11 decreases. When the fuel pressure in the pressurizing chamber 11 becomes lower than the pressure in the suction port 3k in this process, the suction valve 3b is separated from the suction valve seat portion 3a and is opened. The fuel passes through the opening of the suction valve 3b and flows into the pressurizing chamber 11.

After the plunger 2 has completed the inhalation stroke, the plunger 2 shifts to the ascending movement and shifts to the ascending stroke. Here, the electromagnetic coil 3g remains in a non-energized state, and no magnetic urging force acts between the magnetic core 3e and the anchor 3h. The rod urging spring 3m is set to have a urging force necessary and sufficient to keep the suction valve 3b open in a non-energized state. The volume of the pressurizing chamber 11 decreases with the compression movement of the plunger 2. In this state, the fuel once sucked into the pressurizing chamber 11 passes through the opening of the suction valve 3b in the opened state again and is taken through the suction passage. Since it is returned to 10d, the pressure in the pressurizing chamber does not rise. This process is called a return process.

In this state, when the control current from the engine control unit 101 (hereinafter referred to as ECU) is supplied to the electromagnetic suction valve mechanism 3, the current flows through the terminal 16 through the electromagnetic coil 3g. When a current flows through the electromagnetic coil 3g, a magnetic attractive force acts between the magnetic core 3e and the anchor 3h, and if the magnetic attractive force is stronger than the urging force (and other resultant force) of the rod urging spring 3m, the magnetic core The 3e and the anchor 3h collide with each other on the magnetic attraction surface. At this time, the anchor 3h moves the rod 3i away from the suction valve 3b via the rod collar portion 3j.

After that, the suction valve 3b is closed by the urging force of the suction valve urging spring 3l and the fluid force caused by the fuel flowing into the suction passage 10d. After the valve is closed, the fuel pressure in the pressurizing chamber 11 rises with the ascending motion of the plunger 2, and when the pressure exceeds the pressure of the fuel discharge port 12a, the high pressure fuel is discharged through the discharge valve mechanism 8 and the high pressure fuel is discharged to the common rail. It is supplied to 106. This process is called a discharge process.

The ascending stroke from the lower start point to the upper start point of the plunger 2 consists of a return stroke and a discharge stroke. Then, by controlling the energization timing of the coil 3g of the electromagnetic suction valve mechanism 3, the amount of high-pressure fuel discharged can be controlled. If the timing of energizing the electromagnetic coil 3 g is advanced, the ratio of the return stroke during the ascending stroke is small and the ratio of the discharge stroke is large. That is, less fuel is returned to the suction passage 10d, and more fuel is discharged at high pressure. On the other hand, if the timing of energization is delayed, the ratio of the return stroke is large and the ratio of the discharge stroke is small during the ascending stroke. That is, more fuel is returned to the suction passage 10d, and less fuel is discharged at high pressure. The timing of energizing the electromagnetic coil 3g is controlled by a command from the ECU 101.

In this embodiment, the configuration of a normally open solenoid valve has been described as an example of the solenoid suction valve mechanism 3, but if the solenoid valve structure can be opened and closed electromagnetically, the effect on the low pressure portion is the same, which will be described later. A damper cover structure can be applied.

The discharge valve mechanism 8 includes a discharge valve seat 8a, a discharge valve 8b that contacts and separates from the discharge valve seat 8a, a discharge valve spring 8c that urges the discharge valve 8b toward the discharge valve seat 8a, and a stroke (moving distance) of the discharge valve 8b. ) Is determined by the discharge valve stopper 8d, and the plug 8e that blocks the leakage of fuel to the outside. A discharge valve chamber 8g is formed on the secondary side of the discharge valve 8b, and the discharge valve chamber 8g communicates with the fuel discharge port 12a through a horizontal hole 14 formed in the body 1 in the horizontal direction.

When there is no fuel differential pressure between the pressurizing chamber 11 and the discharge valve chamber 8g, the discharge valve 8b is crimped to the discharge valve seat 8a by the urging force of the discharge valve spring 8c and is in a closed state. Only when the fuel pressure in the pressurizing chamber 11 becomes higher than the fuel pressure in the discharge valve chamber 8g, the discharge valve 8b opens against the urging force of the discharge valve spring 8c. When the discharge valve 8b is opened, the high-pressure fuel in the pressurizing chamber 11 is discharged to the common rail 106 (see FIG. 1) through the discharge valve chamber 8g and the fuel discharge port 12a. With the above configuration, the discharge valve mechanism 8 functions as a check valve that limits the fuel flow direction.

In the low pressure fuel chamber 10, a damper 9 is installed to reduce the pressure pulsation generated in the fuel pump 100 from spreading to the fuel pipe 104. When the fuel that has once flowed into the pressurizing chamber 11 is returned to the suction passage 10d through the suction valve body 3b in the opened valve state again for capacity control, the fuel returned to the suction passage 10d returns to the low pressure fuel chamber 10. Pressure pulsation occurs. However, the damper 9 provided in the low-pressure fuel chamber 10 is formed of a metal diaphragm damper in which two corrugated disk-shaped metal plates are laminated on the outer periphery thereof and an inert gas such as argon is injected therein. Pressure pulsation is absorbed and reduced by the expansion and contraction of this metal damper.

The plunger 2 has a large diameter portion 2a and a small diameter portion 2b, and the volume of the sub chamber 7a increases or decreases due to the reciprocating motion of the plunger. The sub chamber 7a communicates with the low pressure fuel chamber 10 by a communication passage 10e (FIG. 3). When the plunger 2 is lowered, a fuel flow is generated from the sub chamber 7a to the low pressure fuel chamber 10, and when the plunger 2 is raised, a fuel flow is generated from the low pressure fuel chamber 10 to the sub chamber 7a.

This makes it possible to reduce the fuel flow rate inside and outside the fuel pump 100 during the suction stroke or the return stroke of the fuel pump 100, and has a function of reducing the pressure pulsation generated inside the fuel pump 100.

The details around the damper cover will be described with reference to FIG. FIG. 4 is a cross-sectional view showing a cross section around the damper cover of FIG.

The body 1 has an annular convex portion 1b at the upper end portion, and a concave portion 1c is formed inside the convex portion 1b in the radial direction, and the concave portion 1c constitutes the lower end portion of the low pressure fuel chamber 10. The damper 9 is sandwiched between the upper support member 21 and the lower support member 22 at the top and bottom, and is fixed to the inside of the damper cover 20.

The damper cover 20 has a top surface portion 20T and a side surface portion 20S extending downward from the outer peripheral edge portion of the top surface portion 20T. The top surface portion 20T is composed of a stepped surface (upper step portion 20T1 and lower step portion 20T2) having a step in the vertical direction (axial direction of the plunger 2).

The upper support member 21 is pressed downward by the pressing portion 20b of the damper cover 20. The pressing portion 20b is composed of a surface facing the body 1 side (a surface facing downward) in the lower portion 20T2 of the damper cover 20. Therefore, the portion of the damper cover 20 that comes into contact with the upper support member 21 is limited to a part of the top surface portion 20T, and it becomes easy to secure a fuel passage around the upper support member 21. Further, the position of the upper support member 21 in the radial direction (horizontal direction) in the low pressure fuel chamber 10 is determined by the outermost peripheral edge 21a coming into contact with the inner peripheral surface of the side surface portion 20S of the damper cover 20.

The lower support member 22 has a side surface portion 22S extending along the inner peripheral surface of the side surface portion 20S of the damper cover 20 and the inner peripheral surface of the annular convex portion 1b of the body 1, and a side surface portion 22S radially inside from the upper end portion of the side surface portion 22S. It has an annular portion 22C formed by being bent into a. The outer peripheral surface of the side surface portion 22S of the lower support member 22 is press-fitted and fixed to the inner peripheral surface of the side surface portion 20S of the damper cover 20, and is also press-fitted and fixed to the inner peripheral surface of the convex portion 1b of the body 1. ..

The upper support member 21 and the lower support member 22 are the second support member 21 and the first support member 22, and since they sandwich the damper 9 with each other, they are also the second sandwich member 21 and the first sandwich member 22. Since the damper 9 is supported on the lower support member 22 and is sandwiched between the lower support member 22 and the upper support member 21 by receiving the pressing force from the upper support member 21, the lower support member 22 is a support member. The upper support member 21 is also called a pressing member.

The press-fitting position of the lower support member 22 with the damper cover 20 is 20a, and the press-fitting position with the convex portion 1b is 1a. The press-fitting portion (first press-fitting portion) 20a and the press-fitting portion (second press-fitting portion) 1a are formed on the outer peripheral surface of the side surface portion 22S of the lower support member 22 and the inner peripheral surface and the convex portion 1b of the side surface portion 20S of the damper cover 20. Since it is constructed between the inner peripheral surface and the inner peripheral surface, it is configured on the same cylindrical surface.

In this case, the press-fitting portion (first press-fitting portion) 20a and the press-fitting portion (second press-fitting portion) 1a are in the press-fitting direction (up and down) of the lower support member (support member) 22, the body 1 and the damper cover (cover portion) 20. In the direction), they are placed in different positions. It is desirable that at least one of the upper support member 21 and the lower support member 22 is elastically deformed to apply an urging force between the damper cover 20, the upper support member 21 and the damper 9 to hold the damper cover 20 and the lower support member 22.

Specifically, the press-fitting portion (first press-fitting portion) 20a is formed between the outer peripheral surface of the lower support member (support member) 22 and the inner peripheral surface of the damper cover (cover portion) 20. The press-fitting portion (second press-fitting portion) 1a is formed between the outer peripheral surface of the lower support member 22 and the inner peripheral surface of the body 1. More specifically, the body 1 has an annular convex portion 1b at an end (portion) covered by the damper cover 20. The damper cover 20 has a top surface portion 20T and a side surface portion 20S extending downward (body 1 side) from the outer peripheral edge portion of the top surface portion 20T. The lower support member 22 has a side surface portion 22S extending along the inner peripheral surface of the side surface portion 20S of the damper cover 20 and the inner peripheral surface of the convex portion 1b of the body 1, and a top surface portion 20T on the side surface portion 22S of the lower support member 22. It has an annular portion 20C formed by being bent inward in the radial direction from the end portion on the side of. The press-fitting portion 20a is formed between the outer peripheral surface of the side surface portion 22S of the lower support member 22 and the inner peripheral surface of the side surface portion 20S of the damper cover 20. The press-fitting portion 1a is formed between the outer peripheral surface of the side surface portion 22S of the lower support member 22 and the inner peripheral surface of the annular convex portion 1b.

That is, in the fuel pump 100 of this embodiment, the body 1, the damper cover (cover portion) 20 that covers the body 1, the lower support member (support member) 22 that supports the damper (accommodated portion) 9, and the lower support A press-fitting portion (first press-fitting portion) 20a formed between the member 22 and the damper cover 20 to fix the lower support member 22 to the damper cover 20, and a lower support member formed between the lower support member 22 and the body 1. The press-fitting portion (second press-fitting portion) 1a, which is formed on the same surface as the surface on which the press-fitting portion 20a of the 22 is formed (the outer peripheral surface portion of the side surface portion 22S) and fixes the lower support member 22 to the body 1, is provided.

Further, a damper (damper mechanism) 9 is arranged on the inner peripheral side of the damper cover (cover portion) 20, and the lower support member (support member) 22 covers the damper 9 with the press-fitting portion (first press-fitting portion) 20a. It is held in contact with the lower surface of 20 (the back surface of the top surface portion 20T).

The lower end of the side surface 20S of the damper cover (cover portion) 20 (lower end of the side surface 20S) and the upper end of the convex portion 1b of the body 1 (upper end of the convex portion 1b) are arranged so as to be in contact with each other. The abutting portion (contact surface) BU is formed and welded at the position of the abutting portion BU. In this case, the press-fitting portion (first press-fitting portion) 20a and the press-fitting portion (second press-fitting portion) 1a are dampers in the press-fitting direction (vertical direction) of the lower support member (support member) 22, the body 1 and the damper cover 20. It is formed up to a range of substantially the same distance from the abutting portion (contact surface) BU between the cover 20 and the body 1. In this embodiment, the press-fitting portion 20a is the range shown in l20, the press-fitting portion 1a is the range shown in l1, and l20 and l1 are equal (l20 = l1). As a result, the fixing force of the lower support member 22 to the damper cover 20 at the press-fitting portion 20a can be made equal to the fixing force of the press-fitting portion 1a to the body 1, and the damper cover 20 and the body 1 can be fixed in a stable state. can do.

The image of the molten part is shown by a broken line on the welded part W. Since the size of the welded portion varies depending on the welding conditions, the image in this figure is shown as an example. The welded portion W for fixing the damper cover (cover portion) 20 and the body 1 is provided on the radial outer side of the lower support member (support member) 22. That is, the welded portion W is irradiated with a laser from the radial outside of the damper cover 20 and the body 1 to perform welding. The welded portion W is provided on the contact surface between the lower end portion of the damper cover 20 (lower end portion of the side surface portion 20S) and the upper end portion of the body 1 (upper end portion of the convex portion 1b), and on the damper cover 20 side and the body 1 side. It is provided so as to straddle.

Since the damper cover 20 and the body 1 are fixed by the press-fitting portion 20a and the press-fitting portion 1a to the lower support member 22, the welded portion W in the abutting portion BU reaches the side surface portion 22S of the lower support member 22. It may be stopped within a range that does not exist and only the fuel is sealed. However, in this embodiment, the molten portion of the welded portion W reaches the side surface portion 22S of the lower support member 22 and has a depth at which a part (outer peripheral side) of the side surface portion 22S in the thickness direction is melted. That is, the welded portion W is formed to a depth that melts a part of the lower support member (support member) 22 in the thickness direction, and a non-melted portion remains in the other portion of the lower support member 22 in the thickness direction.

This makes it possible to ensure that the damper cover 20 is fixed to the body 1. However, when the molten portion of the welded portion W has a depth that melts the entire side surface portion 22S in the thickness direction, the fixed state of the damper cover 20 with respect to the body 1 cannot be maintained. Therefore, the molten portion of the welded portion W has a depth at which a part of the side surface portion 22S in the thickness direction is melted, and a depth at which the entire side surface portion 22S in the thickness direction is not melted.

With the above configuration, spatter generated during welding can be suppressed by the lower support member 22, and spatter scattering can be prevented. Further, since the press-fitting portion 20a and the press-fitting portion 1a are provided up to positions separated from the welded portion W in the press-fitting direction (direction along the outer peripheral surface of the side surface portion 22S), a portion that is not melted during welding remains, and the damper cover. The fixed state of 20 and the body 1 is maintained. Therefore, a jig or the like for fixing the damper cover 20 and the body 1 during the welding operation is not required for the assembly equipment. Further, since the press-fitting portion 20a and the press-fitting portion 1a are formed on the same cylindrical surface by the side surface portion 22S of the lower support member 22, the cylindrical surface of the side surface portion 22S of the lower support member 22 can be formed with a simple method and with high accuracy. Since it can be processed, it is easy to obtain the coaxiality of the press-fitting portion 20a and the press-fitting portion 1a.

In other words, the press-fitting portion 20a and the press-fitting portion 1a are arranged close to each other in the press-fitting direction (vertical direction), and the welded portion W melts the proximity portion of the press-fitting portion 20a and the press-fitting portion 1a. Therefore, the press-fitting portion 20a, the welding portion W, and the press-fitting portion 1a are arranged adjacent to each other in this order in the press-fitting direction (vertical direction).

In this embodiment, a gap g is provided between the lower end surface of the lower holding member 22 and the body 1. That is, a state in which the lower end portion (end portion on the anti-top surface side) of the side surface portion 20S of the damper cover (cover portion) 20 is in contact with the upper end portion (end portion on the damper cover 20 side) of the annular convex portion 1b of the body 1. The lower end of the side surface portion 22S of the lower support member (support member) 22 is arranged so as to be in non-contact with the bottom surface 1d of the concave portion formed inside the annular convex portion 1b. This gap g prevents the lower holding member 22 from being pushed in contact with the bottom surface 1d of the concave portion 1c formed by the convex portion 1b of the body 1 when the damper cover 20 is assembled, and prevents the upper holding member 21 and the lower holding member 22 from being pushed in. It is possible to prevent excessive stress from being generated at 20. However, if the upper holding member 21 or the lower holding member 22 can be sufficiently elastically deformed, it is also feasible to design so as not to provide a gap between the lower end surface of the lower holding member 22 and the body 1.

FIG. 5 is a cross-sectional view showing a cross section of the damper cover subassembly before assembling the body. The cross-sectional position of FIG. 5 is different from that of FIG.

The lower holding member 22 is press-fitted and fixed to the damper cover 20 at a press-fitting portion (press-fitting position) 20a, and the upper support member 21, the damper 9 and the lower support member 22 are assembled as a subassembly on the damper cover 20. By constructing the damper cover sub-assembly that is independently unitized in this way and then assembling this damper cover sub-assembly to the body 1, the damper cover 20, the upper support member 21, the damper 9, and the lower support member are assembled. Assembling 1 to 22 bodies can be simplified.

The suction pipe 5 can be attached to the damper cover 20. In this embodiment, a suction filter 17 is provided in the suction flow path 5a to prevent foreign matter of a predetermined size or larger from flowing from the fuel tank 103 into the fuel pump 100. The fuel that has entered the damper cover 20 passes through the gap flow path (upper and lower communication holes) 20c of the upper support member 21 and the gap flow path (upper and lower communication holes) 20d of the lower support member 22 and flows to the suction passage 10d.

It is desirable that the upper support member 21 and / or one of the lower support members 22 are formed of one press plate. Further, it is desirable that the upper support member 21 and the lower support member 22 are formed with upper and

lower communication holes

20c and 20d by press working on a portion different from the portion that holds the damper 9, specifically, on the outer peripheral side. With this configuration, it is possible to secure a fuel passage from the suction pipe 5 to the body side with an inexpensive configuration.

In this embodiment, the suction pipe 5 is provided above the fuel pump 100, but it may be desirable that the suction pipe 5 is located at a different position depending on the engine layout. For example, if it is difficult to arrange the fuel pipe from the engine in the upper part of the fuel pump 100, the suction pipe 5 may be provided in the central portion of the body 1. In that case, it is not necessary to provide the suction pipe 5 on the damper cover 20.

With the above configuration, the damper cover 20 can be welded to the body 1 at low cost with a small number of parts.

In this embodiment, an example in which the damper cover 20 is fixed to the body 1 is described, but this embodiment can also be applied to the case where other covers are fixed to the body 1. A member including other covers without being limited to the damper cover 20 is referred to as a cover portion. Further, the part housed in the body 1 and covered with the cover part is referred to as a housed part (a part corresponding to the damper 9 of this embodiment).

The present invention is not limited to the above-described examples, and includes various modifications.
For example, the above-described embodiment has been described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to those having all the configurations. Further, it is possible to replace a part of the configuration of the embodiment with another configuration, and it is possible to add another configuration to the configuration of the embodiment.

1 ... Body, 1a ... Second press-fitting part, 2 ... Plunger, 3 ... Electromagnetic suction valve mechanism, 3h ... Anchor, 3i ... Rod, 4 ... Relief valve mechanism, 5 ... Suction pipe, 6 ... Cylinder, 7 ... Seal holder, 8 ... Discharge valve mechanism, 9 ... Damper, 10a ... Low pressure fuel suction port, 11 ... Pressurization chamber, 12 ... Discharge joint, 13 ... Plunger seal, 20 ... Damper cover, 20a ... First press-fitting part, 21 ... Upper support member , 22 ... Lower support member, W ... Welded part.

Claims

With the body
A cover portion that covers the body and
Support members that support the accommodation part and
A first press-fitting portion formed between the support member and the cover portion and fixing the support member to the cover portion,
A second press-fitting portion formed between the support member and the body, formed on the same surface as the surface on which the first press-fitting portion of the support member is formed, and fixing the support member to the body. Equipped fuel pump.
In the fuel pump according to claim 1,
The first press-fitting portion and the second press-fitting portion are fuel pumps arranged at different positions in the press-fitting direction of the support member, the body, and the cover portion.
In the fuel pump according to claim 2.
A fuel pump provided with a welded portion for fixing the cover portion and the body on the radial outer side of the support member.
In the fuel pump according to claim 3,
The first press-fitting portion and the second press-fitting portion are fuel pumps formed from a contact surface between the cover portion and the body in the press-fitting direction to a range of substantially the same distance in the press-fitting direction.
In the fuel pump according to claim 3,
The first press-fitting portion is a fuel pump formed between the outer peripheral surface of the support member and the inner peripheral surface of the cover portion.
In the fuel pump according to claim 3,
The second press-fitting portion is a fuel pump formed between the outer peripheral surface of the support member and the inner peripheral surface of the body.
In the fuel pump according to claim 3,
The body has an annular protrusion at a portion covered by the cover portion.
The cover portion has a top surface portion and a side surface portion extending from the outer peripheral edge portion of the top surface portion toward the side of the body.
The support member has an inner peripheral surface of a side surface portion of the cover portion and a side surface portion extending along the inner peripheral surface of the convex portion of the body.
The first press-fitting portion is formed between the outer peripheral surface of the side surface portion of the support member and the inner peripheral surface of the side surface portion of the cover portion.
The second press-fitting portion is a fuel pump formed between an outer peripheral surface of a side surface portion of the support member and an inner peripheral surface of the annular convex portion.
In the fuel pump according to claim 3,
A fuel pump arranged so that the lower end portion of the cover portion comes into contact with the upper end portion of the body.
In the fuel pump according to claim 3,
A damper mechanism is arranged on the inner peripheral side of the cover portion.
The support member is a fuel pump held by the first press-fitting portion in a state where the damper mechanism is in contact with the lower surface of the cover portion.
In the fuel pump according to claim 3,
The body has an annular protrusion at a portion covered by the cover portion.
In a state where the lower end portion of the cover portion is in contact with the upper end portion of the annular convex portion, the lower end portion of the support member is not in contact with the bottom surface of the concave portion formed inside the annular convex portion. The fuel pump that is located.
In the fuel pump according to claim 8.
A fuel pump having the welded portion on a contact surface between the lower end portion of the cover portion and the upper end portion of the body.
In the fuel pump according to claim 11,
A fuel pump in which the welded portion is formed to a depth that melts a part of the support member in the thickness direction, and a non-melted portion remains in the other portion of the support member in the thickness direction.
With the body
The damper cover that covers the body and
The damper and the support member that supports the damper,
A first press-fitting portion formed between the support member and the damper cover and fixing the support member to the damper cover,
A second press-fitting portion formed between the support member and the body, formed on the same surface as the surface on which the first press-fitting portion of the support member is formed, and fixing the support member to the body. Prepare
The body has an annular protrusion at the end covered by the damper cover.
The damper cover has a top surface portion and a side surface portion extending from the outer peripheral edge portion of the top surface portion toward the body side.
The support member has an inner peripheral surface of a side surface portion of the damper cover and a side surface portion extending along the inner peripheral surface of the convex portion of the body.
The first press-fitting portion is formed between the outer peripheral surface of the side surface portion of the support member and the inner peripheral surface of the side surface portion of the damper cover.
The second press-fitting portion is formed between the outer peripheral surface of the side surface portion of the support member and the inner peripheral surface of the annular convex portion.
A welded portion is provided at the abutting portion between the lower end portion of the side surface portion of the damper cover and the upper end portion of the annular convex portion of the body.
A fuel pump in which the first press-fitting portion, the welded portion, and the second press-fitting portion are arranged adjacent to each other in this order in the press-fitting direction (vertical direction).