Delivery pipe

Abstract

To provide a delivery pipe capable of enhancing sealability between a plug member and a pipe body part.SOLUTION: The fuel supply device includes a cylindrical pipe body part 20 having a fuel supply path 21 through which fuel passes and an opening part 30 communicating with one end part 21A of the fuel supply path 21, and a plug member 50 housed in the opening part 30 to close the one end part 21A of the fuel supply path 21, wherein an inside diameter R1 of the opening part 30 is made larger than an inside diameter R2 of the fuel supply path 21, and the pipe body part 20 has a connection surface 31 connecting an end part on the fuel supply path 21 side in an inner peripheral surface 3OA of the opening part 30 and an end part on the fuel supply path 21 side in an inner peripheral surface 2 IB of the fuel supply path 21. The two surfaces 57 and 58 constituting the corner portion 56 of the plug member 50 are brought into contact with the connecting surface 31, the plug member 50 has an insertion portion 55 inserted into the one end portion 21A of the fuel supply passage 21, and the outer peripheral surface 59 of the insertion portion 55 is brought into contact with the inner peripheral surface 25 of the one end portion 21A of the fuel supply passage 21.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to a delivery pipe. [Background technology]

[0002] Conventionally, in internal combustion engines, etc., a delivery pipe (fuel delivery pipe) that distributes fuel supplied from a fuel supply pipe to injectors provided in each cylinder has been known. As such a delivery pipe, Patent Document 1 discloses a configuration in which an opening of a pipe body having a fuel flow passage is blocked by a plug member (cap), and by abutting a part (edge) of the plug member against the pipe body, fuel leakage from a gap between the plug member and the pipe body is suppressed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-136961 Summary of the Invention [Problem to be solved by the invention]

[0004] In a delivery pipe configured as described above, in which fuel leakage is suppressed by abutting the plug member to the pipe main body, there is a demand for improving quality by increasing the sealing performance between the plug member and the pipe main body.

[0005] The technology disclosed in this specification was developed based on the above circumstances, and aims to provide a delivery pipe that can improve the sealing performance between the plug member and the pipe main body. [Means for solving the problem]

[0006] As a means for solving the above-mentioned problems, the delivery pipe disclosed in this specification comprises a cylindrical pipe main body having a fuel supply passage through which fuel passes and an opening connected to one end of the fuel supply passage, and a plug member that is accommodated in the opening to close the one end of the fuel supply passage, wherein the inner diameter of the opening is larger than the inner diameter of the fuel supply passage, the pipe main body has a connecting surface that connects an end of the inner peripheral surface of the opening that is on the fuel supply passage side and an end of the inner peripheral surface of the fuel supply passage that is on the opening side, the surface of the plug member that faces the connecting surface abuts against the connecting surface, the plug member has an insertion portion that is inserted into the one end of the fuel supply passage, and the outer peripheral surface of the insertion portion abuts against or is arranged opposite to the inner peripheral surface of the one end of the fuel supply passage with a gap therebetween.

[0007] The surface of the plug member facing the connecting surface abuts against the connecting surface, thereby preventing fuel from leaking to the outside through the opening. Furthermore, the outer peripheral surface of the insertion portion abuts against the inner peripheral surface of one end of the fuel supply passage or faces it with a gap. When the outer peripheral surface of the insertion portion abuts against the inner peripheral surface of one end of the fuel supply passage, fuel from the fuel supply passage is prevented from moving toward the contact point of the plug member with the connecting surface. When the outer peripheral surface of the insertion portion faces the inner peripheral surface of one end of the fuel supply passage with a gap, fuel passes through the gap, causing a pressure loss, which reduces the fuel pressure acting on the contact point of the plug member with the connecting surface. These features further improve the sealing performance between the plug member and the pipe main body.

[0008] The plug member may have a second threaded portion formed on its outer peripheral surface that is screwed onto a first threaded portion formed on the inner peripheral surface of the opening. By screwing the second threaded portion onto the first threaded portion, the plug member can be fastened to the pipe main body while being displaced toward the fuel supply passage. During this fastening process, the plug member can be pressed firmly against the connecting surface, thereby improving sealing performance. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a delivery pipe that can further improve the sealing performance between the plug member and the pipe body. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view showing a delivery pipe according to a first embodiment. [Figure 2] FIG. 1 is a perspective view showing a plug member; [Figure 3] Cross-sectional view showing the vicinity of the opening in the pipe body (a view showing the assembly process of the plug member) [Figure 4] Cross-sectional view showing the vicinity of the opening in the pipe body [Figure 5] Cross-sectional view showing the pipe body (corresponding to the cut along line VV in Figure 4) [Figure 6] Cross-sectional view showing a comparative example [Figure 7] 10 is a cross-sectional view showing the vicinity of an opening in a delivery pipe according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] <Embodiment 1> A first embodiment will be described with reference to Figures 1 to 6. In this embodiment, a delivery pipe 10 for supplying fuel to the engine of a vehicle (such as an automobile) will be described. As shown in Figure 1, the delivery pipe 10 includes a cylindrical pipe main body 20 and a plug member 50 disposed inside the pipe main body 20.

[0012] The pipe main body 20 has a circular cross-sectional shape (see FIG. 5 ) and includes a fuel supply passage 21 through which fuel passes. The fuel supply passage 21 is linear and extends along the longitudinal direction of the pipe main body 20, and as shown in FIG. 5 , has a circular cross-sectional shape. As shown in FIG. 1 , a plurality of cylindrical fuel injection valve attachment portions 22 (four in FIG. 1 ) are provided on the outer circumferential surface of the pipe main body 20, lined up at predetermined intervals along the axial direction of the pipe main body 20. The fuel injection valve attachment portions 22 extend in a direction perpendicular to the axial direction of the pipe main body 20 and include a communication hole 23 that communicates with the fuel supply passage 21. A fuel injection valve 11 of the engine is attached to the tip of the communication hole 23 on the side opposite to the fuel supply passage 21.

[0013] A pipe body 24 is provided on the outer peripheral surface of the pipe main body 20. One end of the pipe body 24 is connected to a fuel pump (not shown) provided on the vehicle via a fuel tube (not shown). As a result, fuel supplied from the fuel pump is introduced into the fuel supply path 21 through the inside of the pipe body 24.

[0014] The pipe main body 20, the fuel injection valve attachment portion 22, and the tubular body 24 are integrally formed. The material of each component (pipe main body 20, fuel injection valve attachment portion 22, tubular body 24, and plug member 50) that constitutes the delivery pipe 10 is not particularly limited, but for example, one or more selected from the group consisting of iron, aluminum, alloys, etc. can be used. Among these, examples of alloys include steel and stainless steel. The materials of each component that constitutes the delivery pipe 10 may be the same or different for each component.

[0015] The pipe main body 20 has an opening 30 that communicates with one end of the fuel supply passage 21. The opening 30 is open on one end side (the right side in FIG. 1 ) of the pipe main body 20. The opening 30 has a circular shape in cross section, and an inner diameter R1 of the opening 30 is larger than an inner diameter R2 of the fuel supply passage 21.

[0016] As shown in Fig. 4, the pipe main body 20 has a connecting surface 31 that connects an end of the inner circumferential surface 30A of the opening 30 on the fuel supply passage 21 side to an end of the inner circumferential surface 21B of the fuel supply passage 21 on the opening 30 side. The connecting surface 31 is an inclined surface that extends from the opening 30 side toward the fuel supply passage 21 side and toward the center in the radial direction of the fuel supply passage 21 (to the right in Fig. 4). In addition, a step portion 31B is formed at the end of the connecting surface 31 on the inner circumferential surface 30A side. A groove portion 32 is formed in the connecting surface 31. As shown in Fig. 5, the groove portion 32 extends around the entire circumference of the connecting surface 31 and has an annular shape.

[0017] The plug member 50 is housed in the opening 30 to close one end of the fuel supply passage 21. As shown in Fig. 2, the plug member 50 includes a first cylindrical portion 51, a second cylindrical portion 52 having an outer diameter smaller than that of the first cylindrical portion 51, and an insertion portion 53 that rises from the end face of the second cylindrical portion 52 on the fuel supply passage 21 side.

[0018] A second threaded portion 54 is formed on the outer peripheral surface of the first cylindrical portion 51, and is screwed onto a first threaded portion 33 (see FIG. 4) formed on the inner peripheral surface 30A of the opening 30. As shown in FIG. 1, a recessed portion 55 is formed on the end face of the first cylindrical portion 51 opposite to the fuel supply passage 21. A hexagonal wrench (mounting jig) for rotating the plug member 50 around the axis of the pipe main body 20 can be fitted into this recessed portion 55, for example.

[0019] As shown in FIG. 4 , the portion of the second cylindrical portion 52 that faces the coupling surface 31 is a corner 56. As shown in FIG. 2 , the corner 56 extends around the entire circumference of the second cylindrical portion 52. That is, the corner 56 extends along the extension direction of the groove 32. As shown in FIG. 4 , the tip of the corner 56 is disposed within the groove 32. Two surfaces 57, 58 that constitute the corner 56 abut against portions 34, 35, respectively, on both sides in the groove width direction of the opening edge of the groove 32 in the coupling surface 31. That is, the surface of the plug member 50 that faces the coupling surface 31 (the two surfaces 57, 58 that constitute the corner 56) abuts against the coupling surface 31.

[0020] As shown in Fig. 2, the insertion portion 53 of the plug member 50 is a wall portion having an annular shape in a plan view, and as shown in Fig. 4, is inserted into one end 21A of the fuel supply passage 21. More specifically, the insertion portion 53 is press-fitted into the one end 21A. As a result, the outer peripheral surface 59 of the insertion portion 53 abuts against the inner peripheral surface 25 of the one end 21A of the fuel supply passage 21. As shown in Fig. 1, a recess 52A is formed in the end face of the second cylindrical portion 52 on the fuel supply passage 21 side. As shown in Fig. 4, the internal space 53A of the insertion portion 53 is in communication with the recess 52A.

[0021] In this embodiment, as shown in FIG. 3 , before the plug member 50 is completely assembled to the pipe main body 20, the coupling surface 31 is generally flat. During the process of screwing the second threaded portion 54 of the plug member 50 to the first threaded portion 33, the plug member 50 is displaced toward the fuel supply passage 21 as the screwing occurs, and the two surfaces 57, 58 constituting the corner 56 are pressed firmly against the portions 34, 35 on both sides of the groove 32 in the groove width direction, respectively. As a result, as shown in FIG. 4 , a portion of the coupling surface 31 is plastically deformed, and the two surfaces 57, 58 and the portions 34, 35 on both sides are brought into close contact around the entire circumference, thereby completing the assembly of the plug member 50 to the pipe main body 20. During the process of screwing the second threaded portion 54 of the plug member 50 to the first threaded portion 33, the insertion portion 53 is press-fitted into the one end 21A of the fuel supply passage 21.

[0022] Next, the effects of this embodiment will be described. The delivery pipe 10 of this embodiment includes a cylindrical pipe body 20 having a fuel supply passage 21 through which fuel passes and an opening 30 that communicates with one end 21A of the fuel supply passage 21, and a plug member 50 that is housed in the opening 30 to close one end 21A of the fuel supply passage 21. The inner diameter R1 of the opening 30 is larger than the inner diameter R2 of the fuel supply passage 21, and the pipe body 20 has an end of the inner circumferential surface 30A of the opening 30 on the fuel supply passage 21 side and a plug member 50 that is housed in the opening 30 to close one end 21A of the fuel supply passage 21. The plug member 50 has a connecting surface 31 that connects the end of the inner surface 21B of the plug member 50 on the opening 30 side of the connecting surface 31, and a groove 32 extending around the entire circumference of the connecting surface 31 is formed in the connecting surface 31. The plug member 50 has a corner 56 that extends along the extension direction of the groove 32, and the tip of the corner 56 is arranged within the groove 32. Two surfaces 57, 58 that constitute the corner 56 abut against portions 34, 35 on both sides in the groove width direction of the groove 32, of the opening edge of the groove 32 on the connecting surface 31.

[0023] The two surfaces 57, 58 constituting the corner abut against portions 34, 35 on both sides in the groove width direction of the groove 32 of the opening edge of the groove 32 in the connecting surface 31, respectively, so that the plug member 50 can abut against the pipe main body 20 at two (double) points. This allows for a higher seal between the plug member 50 and the pipe main body 20 compared to a configuration in which the tip 56A of the corner 56 abuts against the connecting surface 31 (a configuration in which the plug member 50 abuts against the pipe main body 20 at one point), as shown in the comparative example in Fig. 6 .

[0024] Furthermore, the delivery pipe 10 of this embodiment includes a cylindrical pipe body 20 having a fuel supply passage 21 through which fuel passes and an opening 30 that is in communication with one end 21A of the fuel supply passage 21, and a plug member 50 that is housed in the opening 30 to close one end 21A of the fuel supply passage 21. The inner diameter R1 of the opening 30 is larger than the inner diameter R2 of the fuel supply passage 21, and the pipe body 20 has a fuel supply passage 21 on an inner circumferential surface 30A of the opening 30. 21 side end of the plug member 50 and the end of the plug member 50 on the opening 30 side of the inner peripheral surface 21B of the fuel supply passage 21, and the surface of the plug member 50 facing the connecting surface 31 (two surfaces 57, 58 constituting the corner portion 56) abuts against the connecting surface 31, and the plug member 50 has an insertion portion 53 that is inserted into one end 21A of the fuel supply passage 21, and the outer peripheral surface 59 of the insertion portion 53 abuts against the inner peripheral surface 25 of one end 21A of the fuel supply passage 21.

[0025] The surface of the plug member 50 facing the coupling surface 31 (two surfaces 57, 58 constituting the corner portion 56) abuts against the coupling surface 31, thereby preventing fuel from leaking from the fuel supply passage 21 to the outside through the opening 30. Furthermore, the outer peripheral surface 59 of the insertion portion 53 abuts against the inner peripheral surface 25 of the one end 21A of the fuel supply passage 21. The outer peripheral surface 59 of the insertion portion 53 abuts against the inner peripheral surface 25 of the one end 21A of the fuel supply passage 21, preventing fuel from flowing toward the contact point of the plug member 50 with the coupling surface 31 (more specifically, the contact point between the surface 58 constituting the corner portion 56 and one portion 35 of the groove 32 in the groove width direction). This further improves the sealing performance between the plug member 50 and the pipe main body 20.

[0026] Additionally, a second threaded portion 54 is formed on the outer peripheral surface of the plug member 50, which is screwed onto the first threaded portion 33 formed on the inner peripheral surface of the opening 30. By screwing the second threaded portion 54 onto the first threaded portion 33, the plug member 50 can be fastened to the pipe main body 20 while being displaced toward the fuel supply passage 21. During this fastening process, the plug member 50 (more specifically, the two surfaces 57, 58 that form the corner) can be pressed firmly against the connecting surface 31, thereby further improving sealing performance.

[0027] <Embodiment 2> A second embodiment will be described with reference to FIG. 7. Portions identical to those in the above embodiment are designated by the same reference numerals, and redundant description will be omitted. In a delivery pipe 110 of this embodiment, the configuration of a plug member 150 differs from that of the above embodiment. As shown in FIG. 7, an insertion portion 153 of the plug member 150 is inserted into one end 21A of the fuel supply passage 21. The outer diameter of the insertion portion 153 is slightly smaller than the inner diameter of the one end 21A of the fuel supply passage 21. As a result, an outer peripheral surface 159 of the insertion portion 153 of the plug member 150 is disposed opposite to an inner peripheral surface 25 of the one end 21A of the fuel supply passage 21, with a gap S1 therebetween. The dimension of the gap S1 is set to, for example, 0.25 mm or less, but is not limited to this.

[0028] According to the present embodiment, the outer peripheral surface 159 of the insertion portion 153 is disposed opposite to the inner peripheral surface 25 at one end 21A of the fuel supply passage 21 with a gap S1 therebetween. In this way, pressure loss occurs as the fuel passes through the gap S1, and it is possible to reduce the pressure of the fuel acting on the contact point of the plug member 150 with the connecting surface 31 (more specifically, the contact point between the surface 58 constituting the corner portion 56 and one portion 35 of the groove portion 32 in the groove width direction).

[0029] <Other embodiments> The technology disclosed in this specification is not limited to the embodiments described above and illustrated in the drawings, and the following embodiments, for example, are also included in the technical scope. (1) The location of the pipe 24 is not limited to that exemplified in the above embodiment and can be changed as appropriate. For example, the pipe 24 may be provided at the end of the pipe main body 20 opposite the opening 30 in the longitudinal direction. (2) The locations and number of the fuel injection valve mounting portions 22 are not limited to those exemplified in the above embodiment and can be changed as appropriate. (3) In the above embodiment, a configuration in which the groove portion 32 is formed on the coupling surface 31 is exemplified. However, as shown in FIG. 6, the groove portion 32 may not be formed, and the tip 56A of the corner portion 56 (the surface of the plug member facing the coupling surface) may abut against the coupling surface 31. [Explanation of symbols]

[0030] 10,110...Delivery pipe, 20...Pipe main body, 21...Fuel supply passage, 21A...One end of the fuel supply passage, 21B...Inner peripheral surface of the fuel supply passage, 25...Inner peripheral surface at one end of the fuel supply passage, 30...Opening, 30A...Inner peripheral surface of the opening, 31...Coupling surface, 33...First threaded portion, 50,150...Plug member, 53...Insertion portion, 54...Second threaded portion, 57,58...Two surfaces constituting a corner portion (surfaces facing the coupling surface in the plug member), 59,159...Outer peripheral surface of the insertion portion, R1...Inner diameter of the opening, R2...Inner diameter of the fuel supply passage, S1...Gap

Claims

1. a cylindrical pipe body having a fuel supply passage through which fuel passes and an opening communicating with one end of the fuel supply passage; a plug member that is received in the opening to close the one end of the fuel supply passage, The inner diameter of the opening is larger than the inner diameter of the fuel supply passage, the pipe main body has a connecting surface that connects an end of the inner circumferential surface of the opening that is on the fuel supply passage side to an end of the inner circumferential surface of the fuel supply passage that is on the opening side, a surface of the plug member facing the coupling surface abuts against the coupling surface; the plug member has an insertion portion that is inserted into the one end of the fuel supply passage, An outer peripheral surface of the insertion portion is disposed in contact with or opposite to an inner peripheral surface of the one end of the fuel supply passage with a gap therebetween.

2. 2. The delivery pipe according to claim 1, wherein a second threaded portion is formed on an outer peripheral surface of the plug member and is screwed onto a first threaded portion formed on an inner peripheral surface of the opening.

Images