WO2023195287A1

WO2023195287A1 - Fuel passage structure

Info

Publication number: WO2023195287A1
Application number: PCT/JP2023/008464
Authority: WO
Inventors: 晃裕大野; 拓真宇野
Original assignee: 愛三工業株式会社
Priority date: 2022-04-06
Filing date: 2023-03-07
Publication date: 2023-10-12
Also published as: JP2023154198A

Abstract

A fuel passage structure (40) comprises: a passage formation member (42) that forms a fuel passage (43) through which flows a pressurized fuel discharged from a fuel pump (16); and a check valve (60) that prevents backflow of the pressurized fuel. Formed in the passage formation member (42) is a T-shaped distribution pipe part (44) which has a vertical pipe part (45) that extends in the vertical direction and a pair of horizontal pipe parts (46, 47) that extend in the horizontal direction from the vertical pipe part (45). The vertical pipe part (45) is connected to the fuel pump (16). One of the horizontal pipe parts (46) is connected to an engine (32). The other one of the horizontal pipe parts (47) is connected to a pressure regulator (18). A valve chamber (57) is formed in the distribution pipe part (44) so as to span to the pair of horizontal pipe parts (46, 47). A valve guide member (59) is provided to the vertical pipe part (45). The check valve (60) has a valve shaft part (60b) that is provided to the valve guide member (59) in a movable manner and a valve part (60a) that is disposed inside the valve chamber (57).

Description

fuel passage structure

The present disclosure relates to a fuel passage structure.

JP 2017-210899A discloses a conventional fuel passage structure including a passage forming member and a check valve. The passage forming member forms a fuel passage through which pressurized fuel discharged from the fuel pump flows. The check valve is configured to prevent backflow of pressurized fuel. A T-shaped distribution pipe portion is formed in the passage forming member. The distribution pipe section has a vertical pipe section extending in the vertical direction and a pair of horizontal pipe sections extending horizontally from the vertical pipe section. The vertical pipe section is connected to a fuel pump. One of the pair of horizontal pipe parts is connected to the internal combustion engine, and the other horizontal pipe part is connected to the pressure regulator. The check valve has a hemispherical valve portion and a valve shaft portion extending vertically upward from the valve portion, and is disposed within the vertical pipe portion so as to be movable in the axial direction (vertical direction). The check valve maintains the residual pressure of the pressurized fuel when the fuel pump is stopped.

In the fuel passage structure of JP-A-2017-210899, in order to suppress seal failure due to the inclination of the check valve, a cylindrical valve that guides the valve stem of the check valve is provided in the vertical pipe part of the passage forming member. A guide member can be provided. In this case, the valve portion is arranged upstream (vertically downward) of the valve stem portion. Therefore, a length sufficient to accommodate the check valve and the valve guide member must be ensured in the vertical tube portion, which increases the length of the vertical tube portion. In turn, this increases the height of the fuel supply device, which deteriorates the ease with which the fuel supply device can be mounted on the vehicle. Therefore, there is a need for improved passageway forming members.

One aspect of the present disclosure is a fuel passage structure in a fuel supply device that supplies fuel in a fuel tank to an internal combustion engine and a pressure regulator using a fuel pump, the fuel passage having a fuel passage through which pressurized fuel discharged from the fuel pump flows. and a check valve that prevents backflow of the pressurized fuel, and the passage forming member includes a vertical pipe portion extending in the vertical direction and a horizontal A T-shaped distribution pipe section is formed having a pair of horizontal pipe parts extending in the direction, the vertical pipe part is connected to the fuel pump, and the vertical pipe part is connected to the fuel pump, and the vertical pipe part is connected to the fuel pump. One horizontal pipe section is connected to the internal combustion engine, and the other horizontal pipe section is connected to the pressure regulator, and the distribution pipe section has a hollow cylindrical valve chamber connected to the pair of horizontal pipe sections. A cylindrical valve guide member extending in the vertical direction is provided in the vertical pipe portion, and the check valve is provided in the valve guide member so as to be movable in the axial direction. The fuel passage structure includes a valve shaft portion, and a valve portion disposed within the valve chamber and opening/closing the vertical pipe portion.

According to the above aspect, the valve shaft portion of the check valve is provided to be movable in the axial direction on the valve guide member provided in the vertical pipe portion of the T-shaped distribution pipe portion in the passage forming member, while the valve shaft portion of the check valve is movable in the axial direction. A valve portion of the check valve is disposed in a valve chamber formed so as to straddle the pair of horizontal pipe portions. Thereby, the length of the vertical pipe portion of the T-shaped distribution pipe portion of the passage forming member can be shortened compared to the case where the valve portion of the check valve is arranged in the vertical pipe portion.

1 is a sectional view showing a fuel supply device according to a first embodiment. FIG. 2 is a cross-sectional view of a portion of the fuel supply device of FIG. 1, showing a check valve in a closed state. FIG. 2 is a cross-sectional view of a portion of the fuel supply device of FIG. 1, showing the check valve in an open state. FIG. 7 is a sectional view showing a stopper portion according to a second embodiment. FIG. 5 is a perspective view showing the stopper portion of FIG. 4; FIG. 7 is a sectional view showing a stopper portion according to a third embodiment. FIG. 7 is a bottom view showing the stopper portion of FIG. 6;

Hereinafter, embodiments of the technology disclosed in this specification will be described using the drawings.

[Embodiment 1]
The fuel supply device 10 according to the present embodiment is installed in a fuel tank 12 mounted on a vehicle such as an automobile, and supplies fuel in the fuel tank 12 to an engine 32 that is an internal combustion engine. be. FIG. 1 is a sectional view showing a fuel supply device 10. As shown in FIG. In FIG. 1, the vertical direction corresponds to the vertical direction, that is, the vertical direction of a fuel tank 12 mounted on a vehicle.

(Fuel supply device)
As shown in FIG. 1, the fuel supply device 10 is provided in a fuel tank 12 that stores liquid fuel as fuel. The fuel tank 12 is a hollow container. The fuel supply device 10 is a module including a sub-tank 14, a fuel pump 16, a pressure regulator 18, a jet pump 20, a passage forming member 42, and the like. The sub-tank 14 is a cup-shaped container with an open top, and is disposed on the bottom of the fuel tank 12 . A fuel inlet 24 that opens laterally is formed at the bottom of the sub-tank 14 .

The fuel pump 16 is a motor-integrated in-tank fuel pump that includes an electric motor section and a pump section provided at the lower end of the motor section. The fuel pump 16 is arranged vertically within the sub-tank 14. A fuel suction port 26 projects from the lower end surface of the fuel pump 16 . A fuel filter 28 that filters fuel taken into the fuel pump 16 is connected to the fuel intake port 26 . A fuel discharge port 30 projects from the upper end surface of the fuel pump 16 .

The pressure regulator 18 adjusts the pressure of the fuel supplied to the engine 32 by the fuel pump 16, that is, the fuel pressure. The pressure regulator 18 has a substantially cylindrical outer shape, and a flange portion 34 projecting in an annular shape is formed at the center in the axial direction (vertical direction in FIG. 1). A surplus fuel discharge port 35 is formed to protrude from the upper end surface of the pressure regulator 18 . The pressure regulator 18 introduces pressurized fuel to be supplied to the engine 32 and discharges, or discharges, surplus fuel (return fuel) that becomes surplus by adjusting the fuel pressure from the surplus fuel discharge port 35.

The jet pump 20 is arranged on the bottom surface of the fuel tank 12. The jet pump 20 has an introduction port 37 that introduces pressurized fuel (driving fuel) and a nozzle 38 that discharges the fuel. The nozzle 38 is arranged to face the fuel inlet 24 of the sub-tank 14. Due to the flow rate of the pressurized fuel jetted from the nozzle 38 toward the fuel inlet 24 of the sub-tank 14, the fuel in the fuel tank 12 is sucked into the pressurized fuel and introduced into the sub-tank 14. That is, the jet pump 20 transfers the fuel in the fuel tank 12 into the sub-tank 14 using the flow of pressurized fuel.

(Fuel passage structure 40)
The fuel passage structure 40 of the fuel supply device 10 includes a passage forming member 42 and a check valve 60. A fuel passage 43 through which pressurized fuel discharged from the fuel pump 16 flows is formed in the passage forming member 42 . The check valve 60 is built into the passage forming member 42 and prevents the pressurized fuel from flowing back. The check valve 60 and its surrounding structure will be explained later.

The passage forming member 42 includes a T-shaped distribution pipe portion 44. The distribution pipe part 44 includes a vertical pipe part 45 extending in the vertical direction, and a pair of

horizontal pipe parts

46 and 47 extending in the horizontal direction (left-right direction in FIG. 1) from the upper end of the vertical pipe part 45. has. In FIG. 1, the horizontal tube portion 46 extending to the right is referred to as a first horizontal tube portion 46, and the horizontal tube portion 47 extending to the left is referred to as a second horizontal tube portion 47. The passage forming member 42 is made of resin.

An inverted cup-shaped pump casing part 48 is integrally formed at the lower end of the vertical pipe part 45. The fuel pump 16 is inserted into the pump casing portion 48 . Accordingly, the fuel discharge port 30 of the fuel pump 16 is connected to the lower end of the vertical pipe portion 45 by insertion. A collar 49 and an O-ring 50 are interposed between the fuel discharge port 30 and the vertical pipe portion 45. The O-ring 50 elastically seals between the fuel discharge port 30 and the vertical tube portion 45. A retaining member 51 for retaining the fuel pump 16 is attached to the lower end of the pump casing portion 48 by a snap fit 52.

The distal end of the first horizontal pipe portion 46 is connected to the engine 32 (more specifically, a delivery pipe equipped with an injector (fuel injection valve) corresponding to each combustion chamber) via a fuel supply pipe 70. Therefore, the pressurized fuel discharged from the fuel pump 16 flows from the vertical pipe section 45 to the first horizontal pipe section 46 and is then supplied to the engine 32 via the fuel supply pipe 70. The first horizontal tube section 46 corresponds to "one horizontal tube section" in this specification.

A connecting tube portion 53 extending vertically downward is integrally formed at the tip of the second horizontal tube portion 47. The connecting tube portion 53 has an inner tube portion 53a and an outer tube portion 53b which form a double inner and outer tube shape. The lower end surfaces of both

tube portions

53a, 53b are open, and the upper end surfaces thereof are closed. The outer tube portion 53b communicates with the second horizontal tube portion 47. That is, the cylindrical space between the inner tube part 53a and the outer tube part 53b and the inside of the second horizontal tube part 47 are communicated with each other. The connecting pipe portion 53 is formed with an elbow-shaped discharge pipe portion 53c. One end of the discharge pipe 53c is connected to the inner pipe 53a, and the other end is opened downward outside the outer pipe 53b. A fuel passage 43 is formed by the inner space of each

tube part

45, 46, 47, 53a, 53b, and 53c of the passage forming member 42.

The upper half of the pressure regulator 18 is connected to the lower end of the outer tube portion 53b by insertion. Accordingly, the surplus fuel discharge port 35 is inserted and connected to the inner tube portion 53a, and the flange portion 34 is brought into contact with the outer tube portion 53b. In this way, the pressure regulator 18 is connected to the second horizontal pipe portion 47. An O-ring 54 is interposed between the pressure regulator 18 and the outer tube portion 53b to elastically seal the two

members

18, 53b. An O-ring 55 is interposed between the surplus fuel discharge port 35 and the inner pipe portion 53a to elastically seal the two members.

The pressure regulator 18 is supplied with the pressurized fuel that has flowed through the outer tube portion 53b from the second horizontal tube portion 47. Moreover, the surplus fuel discharged from the surplus fuel discharge port 35 of the pressure regulator 18 is discharged into the sub-tank 14 from the inner pipe part 53a via the discharge pipe part 53c. Note that the pressure regulator 18 is fixedly held on the connecting pipe portion 53 by a holding member (not shown). The second horizontal pipe portion 47 corresponds to the “other horizontal pipe portion” in this specification.

A branch pipe part 56 is formed at the lower part of the vertical pipe part 45 and projects laterally (to the right in FIG. 1) from between the fuel pump 16 and the check valve 60. The introduction port 37 of the jet pump 20 is connected to the branch pipe section 56 via a tube 72 . Therefore, a part of the pressurized fuel flowing inside the vertical pipe section 45 is supplied from the branch pipe section 56 to the jet pump 20 via the tube 72, thereby operating the jet pump 20.

Note that the fuel discharge port 30 of the fuel pump 16 usually has a built-in check valve for maintaining residual pressure. However, when pressurized fuel discharged from the fuel pump 16 is used in the jet pump 20 as in the present embodiment, a check valve 60 for maintaining residual pressure is required. The check valve 60 is arranged within the distribution pipe section 44 of the passage forming member 42.

(Structure around check valve 60)
FIG. 2 is a sectional view showing the surrounding area of the check valve 60 in a closed state. FIG. 3 is a sectional view showing the surrounding area of the check valve 60 in an open state. As shown in FIG. 2, a hollow cylindrical valve chamber 57 is formed in the distribution pipe section 44 of the passage forming member 42 so as to straddle the pair of

horizontal pipe sections

46, 47. More specifically, the valve chamber 57 is formed at a branching part between the vertical pipe section 45 and the pair of

horizontal pipe sections

46 and 47, and the lower surface of the valve chamber 57 is connected to the lower surface of the pair of

horizontal pipe sections

46 and 47. are formed at the same height. The valve chamber 57 is arranged on the same axis as the vertical tube part 45. A circular hole-shaped upper surface opening 57 a that opens the upper surface of the valve chamber 57 is formed on the upper surface of the distribution pipe section 44 of the passage forming member 42 . At the bottom of the valve chamber 57, an annular valve seat portion 57b surrounding the upper end opening of the vertical tube portion 45 is horizontally formed.

A cap 58 that closes the upper opening 57a of the valve chamber 57 is attached to the distribution pipe section 44. The cap 58 is made of resin. The cap 58 includes a disc-shaped lid portion 58a and a short cylindrical stopper portion 58b that protrudes concentrically from the lower surface of the lid portion 58a. The outer peripheral portion of the lower surface of the lid portion 58a is joined to the mouth edge of the upper surface opening portion 57a of the valve chamber 57 by welding. This eliminates the need for a sealing member such as an O-ring between the passage forming member 42 and the cap 58. The stopper portion 58b restricts the fully open position of the check valve 60 (see FIG. 3). The stopper portion 58b has a lower surface, that is, a contact surface 58c, which makes surface contact with the upper surface of the valve portion 60a when the check valve 60 is fully opened. In the fully open position of the check valve 60, the valve portion 60a of the check valve 60 is located in the vertical center of the valve chamber 57.

A valve guide member 59 extending in the vertical direction is integrally formed within the upper end of the vertical pipe portion 45. The upper end surface of the valve guide member 59 is arranged one step lower than the upper surface of the valve seat portion 57b. The valve guide member 59 includes a cylindrical bearing portion 59a and a plurality of (for example, three) band-shaped connecting portions 59b installed between the bearing portion 59a and the vertical tube portion 45. The connecting portions 59b are arranged radially at equal intervals in the circumferential direction. A plurality of channels 59c extending in the axial direction (vertical direction) are formed between connecting portions 59b adjacent in the circumferential direction between the vertical tube portion 45 and the bearing portion 59a.

(Check valve 60)
As shown in FIG. 2, the check valve 60 is a poppet valve having a disk-shaped valve portion 60a and a cylindrical valve shaft portion 60b concentrically protruding from the lower end surface of the valve portion 60a. . The upper surface of the valve portion 60a is formed into a plane perpendicular to the axis of the check valve 60. An annular convex portion 60c having a mountain-shaped cross section and projecting downward is formed on the outer peripheral portion of the lower surface of the valve portion 60a. An annular plate-shaped rubber sealing material 61 is attached to the lower surface of the valve portion 60a by baking. The outer peripheral portion of the sealing material 61 covers the lower surface of the annular convex portion 60c.

The valve shaft portion 60b is inserted into the bearing portion 59a of the valve guide member 59 so as to be movable in the axial direction (vertical direction). The valve part 60a is arranged in the valve chamber 57 and opens and closes the vertical pipe part 45. That is, as shown in FIG. 3, the check valve 60 is opened by floating due to the pressure of the pressurized fuel from the fuel pump 16. At this time, the valve portion 60a (including the sealing material 61) is separated from the valve seat portion 57b, thereby allowing the pressurized fuel to flow downstream (see the arrow in FIG. 3). Further, as shown in FIG. 2, the check valve 60 closes due to the backflow of fuel in both the

lateral pipe portions

46, 47 and their own weight. At this time, the valve portion 60a is seated on the valve seat portion 57b. The sealing material 61 elastically seals between the valve portion 60a and the valve seat portion 57b.

(Operation of fuel supply device 10)
When the fuel pump 16 is driven, fuel in the sub-tank 14 is sucked into the fuel pump 16 through the fuel filter 28. The pressurized fuel discharged from the fuel discharge port 30 of the fuel pump 16 passes through the vertical pipe section 45 of the passage forming member 42, and is supplied to the engine 32 from the first horizontal pipe section 46 through the fuel supply pipe 70. At this time, the check valve 60 is opened by being pushed up by the forward flow of pressurized fuel.

Further, the pressurized fuel that has passed through the vertical tube portion 45 of the passage forming member 42 is supplied from the second horizontal tube portion 47 to the pressure regulator 18 through the outer tube portion 53b. The pressure regulator 18 adjusts the pressure of pressurized fuel supplied to the engine 32. Then, the surplus fuel (return fuel) is discharged from the surplus fuel discharge port 35 of the pressure regulator 18 through the inner tube portion 53a and the discharge tube portion 53c. Further, a part of the pressurized fuel flowing through the vertical pipe section 45 of the passage forming member 42 is supplied from the branch pipe section 56 to the jet pump 20 via the tube 72 . The jet pump 20 uses the flow of pressurized fuel to transfer the fuel in the fuel tank 12 into the sub-tank 14 together with the pressurized fuel.

Furthermore, when the drive of the fuel pump 16 is stopped, the check valve 60 is closed by being pushed down by the backflow of fuel in both the

horizontal pipe portions

46 and 47 and its own weight. This prevents backflow of fuel and maintains the residual pressure of the pressurized fuel.

(Actions and effects of Embodiment 1)
According to this embodiment, the valve shaft portion 60b of the check valve 60 is provided in the valve guide member 59 provided in the vertical pipe portion 45 of the T-shaped distribution pipe portion 44 in the passage forming member 42 so as to be movable in the axial direction. On the other hand, a valve portion 60a of the check valve 60 is arranged in a valve chamber 57 formed so as to straddle the pair of

horizontal pipe portions

46 and 47 of the distribution pipe portion 44. Thereby, the length of the vertical pipe part 45 in the T-shaped distribution pipe part 44 of the passage forming member 42 can be shortened compared to the case where the valve part 60a of the check valve 60 is arranged in the vertical pipe part 45. I can do it. In turn, it is possible to suppress an increase in the height of the fuel supply device 10 and improve the mountability of the fuel supply device 10 on a vehicle.

Further, a valve guide member 59 is integrally formed with the passage forming member 42. Therefore, compared to the case where the passage forming member 42 and the valve guide member 59 are formed separately, the number of parts and the number of assembly steps can be reduced.

Furthermore, the fully open position of the check valve 60 can be restricted by the stopper portion 58b provided on the cap 58 that closes the upper surface opening 57a of the valve chamber 57 of the passage forming member 42. Therefore, the weight of the check valve 60 can be reduced compared to the case where the check valve 60 is provided with a regulating member that regulates the fully open position.

Furthermore, when the check valve 60 is fully open, the valve portion 60a comes into surface contact with the stopper portion 58b, so that the inclination of the check valve 60 can be suppressed.

[Embodiment 2]
Since this embodiment is a modification of the stopper portion 58b of the cap 58 of Embodiment 1, the modified portion will be explained, and the same parts as in Embodiment 1 will be given the same reference numerals and redundant explanations will be omitted. Omitted. FIG. 4 is a sectional view showing the stopper portion 58b. FIG. 5 is a perspective view of the stopper portion 58b.

As shown in FIGS. 4 and 5, a cross groove 58d is formed on the contact surface 58c of the stopper portion 58b of the cap 58. The cross groove 58d is opened on the outer peripheral surface of the stopper portion 58b. The cross groove 58d corresponds to a "recess" in this specification.

According to this embodiment, the contact surface 58c of the stopper part 58b is formed with a cross groove 58d that opens on the outer surface of the stopper part 58b, so that when the check valve 60 is fully opened (two points in FIG. By opening the cross groove 58d into the valve chamber 57 without being blocked by the valve portion 60a (see chain line 60), it is possible to prevent the check valve 60 from sticking to the stopper portion 58b. The cross groove 58d of the stopper portion 58b is also effective in reducing the contact area between the valve portion 60a and the stopper portion 58b when the check valve 60 is fully open.

[Embodiment 3]
Since this embodiment is a modification of the stopper portion 58b of the cap 58 of the second embodiment, the modified portion will be explained, and the same parts as those of the first embodiment will be given the same reference numerals and redundant explanations will be omitted. Omitted. FIG. 6 is a sectional view showing the stopper portion 158b, and FIG. 7 is a bottom view of the stopper portion 158b.

As shown in FIGS. 6 and 7, the outer diameter of the stopper portion 158b of this embodiment is larger than that of the stopper portion 58b of the second embodiment. Furthermore, a cross groove 158d that opens on the outer surface of the stopper portion 158b is formed on the contact surface 158c of the stopper portion 158b. A hollow cylindrical groove 158e communicating with the cross groove 158d is concentrically formed on the contact surface 158c. The cross groove 158d including the groove 158e corresponds to a "recess" in this specification.

Also according to this embodiment, the same functions and effects as those of the second embodiment can be obtained. Furthermore, since the outer diameter of the stopper portion 158b is larger than that of the stopper portion 58b of the second embodiment, the inclination of the check valve 60 when it is fully open (see the two-dot chain line 60 in FIG. 6) is reduced. The suppression effect can be improved. Further, the groove 158e is effective in reducing the contact area between the valve portion 60a and the stopper portion 158b when the check valve 60 is fully opened. Further, a groove similar to the groove 158c of this embodiment may be formed on the contact surface 58c of the stopper portion 58b of the second embodiment.

[Other embodiments]
The technology disclosed in this specification is not limited to the embodiments described above, and can be implemented in various other forms. For example, the valve guide member 59 may be formed separately from the passage forming member 42 and attached to the passage forming member 42. Further, the

stopper portions

58d and 158d are not limited to a short cylindrical shape, and may have any protrusion shape such as a polygonal columnar shape, a trapezoidal shape, a truncated cone shape, or the like. Further, the shape, number, etc. of the recessed portions of the contact surfaces 58c, 158c of the

stopper portions

58d, 158d are arbitrary.

Furthermore, the contents of the present disclosure can be implemented in various ways. A first aspect is a fuel passage structure in a fuel supply device that supplies fuel in a fuel tank to an internal combustion engine and a pressure regulator by a fuel pump, the fuel passage forming a fuel passage through which pressurized fuel discharged from the fuel pump flows. and a check valve that prevents backflow of the pressurized fuel. A T-shaped distribution pipe part is formed, the vertical pipe part being connected to the fuel pump, and one of the pair of horizontal pipe parts extending to the fuel pump. A horizontal pipe portion is connected to the internal combustion engine, the other horizontal pipe portion is connected to the pressure regulator, and a hollow cylindrical valve chamber straddles the pair of horizontal pipe portions in the distribution pipe portion. The vertical pipe portion is provided with a cylindrical valve guide member extending in the vertical direction, and the check valve is provided in the valve guide member so as to be movable in the axial direction. The fuel passage structure includes a valve shaft portion and a valve portion disposed within the valve chamber and opening/closing the vertical pipe portion.

According to the first aspect, the valve shaft portion of the check valve is provided to be movable in the axial direction in the valve guide member provided in the vertical pipe portion of the T-shaped distribution pipe portion in the passage forming member, and the distribution pipe portion A valve portion of the check valve is disposed in a valve chamber formed so as to straddle a pair of horizontal pipe portions. Thereby, the length of the vertical pipe portion of the T-shaped distribution pipe portion of the passage forming member can be shortened compared to the case where the valve portion of the check valve is arranged in the vertical pipe portion.

A second aspect is the fuel passage structure of the first aspect, in which the valve guide member is integrally formed with the passage forming member.

According to the second aspect, the number of parts and the number of assembly steps can be reduced compared to the case where the passage forming member and the valve guide member are formed separately.

A third aspect is the fuel passage structure according to the first or second aspect, wherein a cap for closing an upper opening of the valve chamber is attached to the distribution pipe section, and the cap includes the fuel passage structure of the first or second aspect. This fuel passage structure is provided with a stopper portion that restricts the fully open position of the check valve.

According to the third aspect, the fully open position of the check valve can be regulated by the stopper portion provided on the cap that closes the upper opening of the valve chamber of the passage forming member. Therefore, the weight of the check valve can be reduced compared to when the check valve is provided with a regulating member that regulates the fully open position.

A fourth aspect is the fuel passage structure according to the third aspect, wherein the stopper portion is formed in a protrusion shape having a contact surface with which the valve portion makes surface contact when the check valve is fully opened; The contact surface has a fuel passage structure in which a recess opening to the outer surface of the stopper part is formed.

According to the fourth aspect, the valve part makes surface contact with the stopper part when the check valve is fully opened, so that the inclination of the check valve can be suppressed. In addition, the contact surface of the stopper part is formed with a recess that opens on the outer surface of the stopper part, so that when the check valve is fully opened, the recess is not blocked by the valve part and opens into the valve chamber. , it is possible to prevent the check valve from sticking to the stopper part. Further, the concave portion of the stopper portion is effective in reducing the contact area between the valve portion and the stopper portion when the check valve is fully opened.

Claims

A fuel passage structure in a fuel supply device that supplies fuel in a fuel tank to an internal combustion engine and a pressure regulator by a fuel pump,
a passage forming member forming a fuel passage through which pressurized fuel discharged from the fuel pump flows;
a check valve that prevents backflow of the pressurized fuel;
It is equipped with
The passage forming member is formed with a T-shaped distribution pipe portion having a vertical pipe portion extending in the vertical direction and a pair of horizontal pipe portions extending in the horizontal direction from the vertical pipe portion. ,
The vertical pipe portion is connected to the fuel pump,
One of the pair of horizontal pipe parts is connected to the internal combustion engine, and the other horizontal pipe part is connected to the pressure regulator,
A hollow cylindrical valve chamber is formed in the distribution pipe part so as to straddle the pair of horizontal pipe parts,
The vertical pipe portion is provided with a cylindrical valve guide member extending in the vertical direction,
The check valve has a fuel passage structure including a valve shaft portion that is movably provided in the valve guide member in an axial direction, and a valve portion that is disposed within the valve chamber and opens and closes the vertical pipe portion.
The fuel passage structure according to claim 1,
In the fuel passage structure, the valve guide member is integrally formed with the passage forming member.
The fuel passage structure according to claim 1 or 2,
A cap that closes an upper opening of the valve chamber is attached to the distribution pipe section,
A fuel passage structure, wherein the cap is provided with a stopper portion that restricts a fully open position of the check valve.
The fuel passage structure according to claim 3,
The stopper portion is formed in a protrusion shape having a contact surface with which the valve portion makes surface contact when the check valve is fully opened;
In the fuel passage structure, the contact surface is formed with a recess that opens to an outer surface of the stopper part.