Fuel delivery pipe and throttle device

Abstract

To provide a fuel delivery pipe and a throttle device, which can be developed into a wide variety of products while reducing manufacturing costs.SOLUTION: A fuel delivery pipe 1 comprises a first resin pipe 10 having a first fuel flow passage 12 through which a fuel flows, an inlet port 14 for taking in the fuel into the first fuel flow passage 12, and one or more first communication ports 16 connecting the first fuel flow passage 12 to one or more fuel injectors 100. The hollow part 13 of the first resin pipe 10, which forms the first fuel flow passage 12, includes a first large diameter portion 22 that opens to one pipe end 11 of the first resin pipe 12, and a first small diameter portion 24 that is located closer to the center of the first resin pipe 10 than the first large diameter portion 22. The inner wall 20 of the first resin pipe 10, which defines the hollow part 13, includes a first step 28 provided at a position between the first large diameter portion 22 and the first small diameter portion 24 . A distance L from the first step 28 to the one pipe end 11 of the first resin pipe 10 is greater than an inner diameter D1 of the first large diameter portion 22.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] The present disclosure relates to a fuel delivery pipe and a throttle device. [Background technology]

[0002] 2. Description of the Related Art Fuel delivery pipes for supplying fuel to fuel injectors have been known in the past.

[0003] For example, Patent Document 1 describes a fuel delivery pipe in which a plurality of connectors and a resin pipe are connected to each other, and a fuel injection valve is connected to each of the plurality of connectors. Patent Document 2 describes a fuel delivery pipe with improved airtightness achieved by a double seal structure consisting of an O-ring seal structure and a welded seal structure. Specifically, the end opening of the main pipe section, which has multiple injector mounting portions, is closed with a plug via an O-ring, and a cap to prevent the plug from coming off is welded to the opening of the main pipe section, thereby achieving the double seal structure of the fuel delivery pipe. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-28028 [Patent Document 2] Japanese Patent Application Laid-Open No. 2000-218699 Summary of the Invention [Problem to be solved by the invention]

[0005] Generally, when manufacturing a wide variety of fuel delivery pipes according to engine specifications, a mold for molding the fuel delivery pipe must be prepared for each type, which increases manufacturing costs.

[0006] In this regard, the fuel delivery pipe described in Patent Document 1 aims to reduce manufacturing costs by sharing the connector to which the fuel injection valve is connected and the resin pipe between different types of products. However, in the fuel delivery pipe described in Patent Document 1, the connector to which the fuel injection valve is connected and the resin pipe are separate parts, which causes a problem of complicated assembly work due to the increased number of parts.

[0007] The fuel delivery pipe described in Patent Document 2 is originally intended to achieve a double seal structure, and is not intended to reduce manufacturing costs by standardizing molds between different types of fuel delivery pipes.

[0008] In view of the above circumstances, at least some embodiments of the present invention have an object to provide a fuel delivery pipe and a throttle device that can be developed into a wide variety of products while reducing manufacturing costs. [Means for solving the problem]

[0009] A fuel delivery pipe according to at least some embodiments of the present invention comprises: A fuel delivery pipe for supplying fuel to at least one fuel injector, a first resin pipe having a first fuel flow path through which fuel flows, an inlet port for taking in fuel into the first fuel flow path, and one or more first communication ports for communicating the first fuel flow path with one or more fuel injectors; The hollow portion of the first resin pipe forming the first fuel flow path is a first large diameter portion that opens at one pipe end of the first resin pipe; a first small diameter portion located closer to the center of the first resin pipe than the first large diameter portion and having a smaller diameter than the first large diameter portion; Including, an inner wall of the first resin pipe defining the hollow portion includes a first step provided at a position between the first large diameter portion and the first small diameter portion; A distance L from the first step to one pipe end of the first resin pipe is greater than the inner diameter D1 of the first large diameter portion. [Effects of the Invention]

[0010] According to at least some embodiments of the present invention, by using the first resin pipe alone or together with another pipe (second resin pipe), it is possible to accommodate a plurality of product specifications with different numbers of fuel injectors. Therefore, the first resin pipe can be used as a common component, and a wide variety of fuel delivery pipes can be manufactured at low cost. [Brief explanation of the drawings]

[0011] [Figure 1A] FIG. 2 is a cross-sectional view of a fuel delivery pipe according to one embodiment. [Figure 1B] FIG. 10 is a cross-sectional view of a fuel delivery pipe according to another embodiment. [Figure 2] FIG. 2 is a cross-sectional view of a first resin pipe according to one embodiment. [Figure 3A] FIG. 2 is a perspective view of a fuel delivery pipe according to one embodiment. [Figure 3B] FIG. 3B is a cross-sectional view taken along line AA in FIG. 3A. [Figure 4A] FIG. 10 is a perspective view of a fuel delivery pipe according to another embodiment. [Figure 4B] FIG. 4B is a cross-sectional view taken along line BB in FIG. 4A. [Figure 5] 1 is a perspective view of a throttle device according to one embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, several embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present invention.

[0013] Fig. 1A is a cross-sectional view of a fuel delivery pipe according to one embodiment. Fig. 1B is a cross-sectional view of a fuel delivery pipe according to another embodiment. The fuel delivery pipe 1B shown in Fig. 1B differs from the fuel delivery pipe 1A shown in Fig. 1A in that it includes a second resin pipe 50 in addition to a first resin pipe 10. Below, we will first describe the configuration common to the fuel delivery pipes 1A and 1B, and then describe the characteristic configurations of each of the fuel delivery pipes 1A and 1B. In the following description, fuel delivery pipes according to some embodiments, including the fuel delivery pipes 1A and 1B, may be referred to as the fuel delivery pipe 1 (1A, 1B).

[0014] The fuel delivery pipe 1 (1A, 1B) is a part of a fuel supply system for supplying fuel to at least one fuel injector. The fuel delivery pipe 1 (1A, 1B) may be configured to supply fuel to a plurality of fuel injectors provided corresponding to a plurality of cylinders of the engine. The fuel injector may be attached to the throttle body of the throttle device, or may be provided in a location in the intake passage downstream of the throttle device (for example, in a rubber boot between the throttle device and the engine).

[0015] In some embodiments, as shown in FIGS. 1A and 1B, the fuel delivery pipe 1 (1A, 1B) includes a first resin pipe 10 having a hollow structure. The first resin pipe 10 is, for example, an injection-molded product obtained by injecting a resin material into a mold.

[0016] As shown in FIGS. 1A and 1B, the first resin pipe 10 includes a first fuel flow path 12 through which fuel flows, an inlet port 14 for taking in fuel into the first fuel flow path 12, and one or more first communication ports 16 that connect the first fuel flow path 12 to a fuel injector (not shown). 1A and 1B, the first resin pipe 10 has two first communication ports 16. In other embodiments, the first resin pipe 10 has one first communication port 16. In yet other embodiments, the first resin pipe 10 has three or more first communication ports 16.

[0017] The first fuel flow path 12 extends inside the first resin pipe 10 along the axial direction of the first resin pipe 10 and opens at one pipe end 11 of the first resin pipe 10. The first fuel flow path 12 is closed at the other pipe end of the first resin pipe 10 by a flow path wall. More specifically, the first fuel flow path 12 is formed by a hollow portion 13 extending axially within the first resin pipe 10 (see FIG. 1A). The hollow portion 13 includes a first large diameter portion 22 that opens to one pipe end 11 of the first resin pipe 10, and a first small diameter portion 24 that is located closer to the center of the first resin pipe 10 than the first large diameter portion 22. The inner diameter of the first small diameter portion 24 is smaller than the inner diameter D1 of the first large diameter portion 22. In addition to the first large diameter portion 22 and the first small diameter portion 24, the hollow portion 13 of the first resin pipe 10 may have a straight flow path portion 26 that communicates with the inlet port 14 and the first communication port 16 described below. In the example shown in FIGS. 1A and 1B , the straight flow path portion 26 of the hollow portion 13 is located on the opposite side of the first small diameter portion 24 from the first large diameter portion 22, and extends along the axial direction of the first resin pipe 10 to the pipe end opposite the pipe end 11. The straight flow path portion 26 of the hollow portion 13 has an end opposite to the end connected to the first small diameter portion 24 that is closed by the end wall of the first resin pipe 10. The inner diameter of the straight flow path portion 26 is the same as the inner diameter of the first small diameter portion 24.

[0018] The first resin pipe 10 has an inner wall 20 that defines a hollow portion 13 . The inner wall 20 of the first resin pipe 10 includes a first step 28 located between the first large diameter portion 22 and the first small diameter portion 24. The first step 28 is a step between the large diameter circumferential wall 23 that defines the first large diameter portion 22 and the small diameter circumferential wall 25 that defines the first small diameter portion 24. The large diameter circumferential wall 23 and the small diameter circumferential wall 25 are each circumferential walls that are continuous in the circumferential direction, and the inner diameter (D1) of the large diameter circumferential wall 23 is larger than the inner diameter of the small diameter circumferential wall 25. In the exemplary embodiment shown in FIGS. 1A and 1B , the step surface of the first step 28 extends along the radial direction of the first resin pipe 10 and connects the large diameter circumferential wall 23 and the small diameter circumferential wall 25. 1A and 1B, the inner wall 20 of the first resin pipe 10 has, in addition to the large-diameter peripheral wall 23, the small-diameter peripheral wall 25, and the first step 28, another peripheral wall 27 that defines the linear flow path portion 26 of the hollow portion 13. An inlet flow path 15 and a communication path 17, which will be described later, open into the other peripheral wall 27.

[0019] In some embodiments, the distance L along the axial direction of the first resin pipe 10 from the first step 28 to the pipe end 11 is greater than the inner diameter D1 of the first large diameter portion 22. The ratio L / D1 of the distance L to the inner diameter D1 may be 1.3 or greater. When the distance L is greater than the inner diameter D1, when the tip portion 60 of the second resin pipe 50 described below is fitted into the first large diameter portion 22 from the pipe end 11 side of the first resin pipe 10, the second resin pipe 50 can be securely supported on the first resin pipe 10 while maintaining the concentricity of the first resin pipe 10 and the second resin pipe 50.

[0020] The inlet port 14 is provided to protrude from the outer peripheral surface of the first resin pipe 10 in a direction (e.g., a radial direction) intersecting the axial direction of the first resin pipe 10. An inlet flow path 15 communicating with the first fuel flow path 12 is formed inside the inlet port 14. The inlet flow path 15 opens to another peripheral wall 27 that defines the linear flow path portion 26 of the hollow portion 13 of the first resin pipe 10. Similarly, the first communication port 16 is provided to protrude from the outer peripheral surface of the first resin pipe 10 in a direction (e.g., a radial direction) intersecting the axial direction of the first resin pipe 10, and a communication passage 17 that communicates with the first fuel flow passage 12 is formed inside the first communication port 16. The communication passage 17 opens to another peripheral wall 27 that defines the linear flow passage portion 26 of the hollow portion 13 of the first resin pipe 10.

[0021] In some embodiments, as shown in FIGS. 1A and 1B, the inlet port 14 is provided between two adjacent first communication ports 16 in the axial direction of the first resin pipe 10. The position where the inlet port 14 is formed may be offset from the position where the first communication port 16 is formed in the circumferential direction of the first resin pipe 10. In the exemplary embodiment shown in Figures 1A and 1B, the angular position of the inlet port 14 and the angular position of the first communication port 16 are offset by 180 degrees in the circumferential direction of the first resin pipe 10. In some other embodiments, the angular position of the inlet port 14 and the angular position of the first communication port 16 are offset by 60 degrees or more.

[0022] In some embodiments, the ratio L / P of the distance L from the first step 28 to the pipe end 11 to the distance (pitch P) between two adjacent first communication ports 16 along the axial direction of the first resin pipe 10 is 0.15 or more. The ratio L / P of the distance L to the pitch P may be 0.2 or more. 1A, the pitch P between two adjacent first communication ports 16 is determined based on the center position of each first communication port 16. In a fuel delivery pipe 1B in which a second resin pipe 50 is assembled to a first resin pipe 10, the pitch P between two adjacent first communication ports 16 is generally approximately equal to the pitch P' between adjacent first communication ports 16 and second communication ports 56. Therefore, the ratio L / P is an index indicating the proportion of the mating length L between the first resin pipe 10 and the second resin pipe 50 to the pitch P' between the first communication port 16 and the second communication port 56 when the second resin pipe 50 is assembled to the first resin pipe 10.

[0023] In some embodiments, as shown in FIG. 1A, a fuel delivery pipe 1A includes a first resin pipe 10 and a cap 40 coupled to a pipe end 11 of the first resin pipe 10. The cap 40 functions as a lid that closes the opening of the first large diameter portion 22 of the hollow portion 13 in the pipe end 11. In one embodiment, the cap 40 may be joined to the pipe end 11 of the first resin pipe 10 by partially melting the resin of the pipe end 11 and joining (welding) it to the inner end surface 41 of the cap 40. In another embodiment, the pipe end 11 and the cap 40 may be joined by fastening the flange portion of the pipe end 11 of the first resin pipe 10 to the outer periphery of the cap 40 using a clip. As described above, the first large diameter portion 22 of the hollow portion 13 is located closer to the pipe end 11 of the first resin pipe 10. Therefore, when realizing a fuel delivery pipe 1A using the first resin pipe 10 alone, the operation of joining (for example, welding or fastening) the cap 40 to the pipe end 11 can be easily performed on the outer periphery of the opening of the first large diameter portion 22, which has a relatively large diameter at the pipe end 11.

[0024] 1A , at least the first step 28 of the inner wall 20 of the first resin pipe 10 faces the cap 40 across the first fuel flow path 12. That is, no other member exists between the step surface of the first step 28 of the first resin pipe 10 and the inner end surface 41 of the cap 40. The first fuel flow path 12 is sealed at the joint between the cap 40 and the first resin pipe 10. That is, the first fuel flow path 12 is sealed at the joint between the pipe end 11 of the first resin pipe 10 and the inner end surface 41 of the cap 40.

[0025] In some other embodiments, as shown in FIG. 1B, a fuel delivery pipe 1B includes a second resin pipe 50 connected to the first resin pipe 10. The second resin pipe 50 includes a second fuel flow path 52 through which fuel flows, and one or more second communication ports 56 for connecting the second fuel flow path 52 to a fuel injector. In the exemplary embodiment shown in FIG. 1B, the second resin pipe 50 has two second communication ports 56. In other embodiments, the number of second communication ports 56 is one or three or more. The position at which the second communication port 56 is formed in the circumferential direction of the second resin pipe 50 may coincide with the position at which the first communication port 16 is formed in the first resin pipe 10.

[0026] 1B , the second fuel flow path 52 of the second resin pipe 50 extends within the second resin pipe 50 along the axial direction of the second resin pipe 50 and opens at a tip 60 of the second resin pipe 50. The second fuel flow path 52 is closed at the end opposite the tip 60 of the second resin pipe 50 by an end wall of the second resin pipe 50. The tip 60 of the second resin pipe 50 is fitted into the first large diameter portion 22 of the hollow portion 13 of the first resin pipe 10, and the first fuel flow path 12 in the first resin pipe 10 communicates with the second fuel flow path 52 in the second resin pipe 50. In this manner, fuel from the first fuel flow path 12 can flow into the second fuel flow path 52, and fuel from the first fuel flow path 12 and the second fuel flow path 52 is supplied to the injector via the first communication port 16 and the second communication port 56. 1B, the second resin pipe 50 does not have a fuel inlet port other than the inlet opening of the second fuel flow passage 52 at the tip portion 60. In other embodiments, the second resin pipe 50 has a fuel inlet port similar to the inlet port 14 of the first resin pipe 10. The inner diameter D2 of the second fuel flow passage 52 is smaller than the inner diameter D1 of the first large diameter portion 22 of the hollow portion 13 of the first resin pipe 10.

[0027] 1B , the distal end portion 60 of the second resin pipe 50 includes a second small diameter portion 64, a second large diameter portion 62 located closer to the base end of the second resin pipe 50 than the second small diameter portion 64, and a second step 66 provided between the second small diameter portion 64 and the second large diameter portion 62. The second large diameter portion 62 has a larger outer diameter than the second small diameter portion 64. In the exemplary embodiment shown in FIG. 1B , the step surface of the second step 66 extends along the radial direction of the second resin pipe 50 and connects the outer circumferential surface of the second resin pipe 50 at the second small diameter portion 64 and the outer circumferential surface of the second resin pipe 50 at the second large diameter portion 62. In this manner, the tip portion 60 of the second resin pipe 50 has the second small diameter portion 64, the second step 66, and the second large diameter portion 62 in this order from the tip side.

[0028] In some embodiments, as shown in FIG. 1B, the fuel delivery pipe 1B includes a seal ring 70 for sealing the connection between the first resin pipe 10 and the second resin pipe 50. The seal ring 70 is an annular seal member that may be, for example, an O-ring. The seal ring 70 is held in an axial position between the first step 28 of the first resin pipe 10 and the second step 66 of the second resin pipe 50, and in a radial position between the large diameter peripheral wall 23 that defines the first large diameter portion 22 of the inner wall 20 of the first resin pipe 10 and the second small diameter portion 64 of the second resin pipe 50. In other words, the seal ring 70 is located between the first step 28 and the second step 66 that face each other in the axial direction, and is located between the large diameter peripheral wall 23 and the outer peripheral surface of the second resin pipe 50 at the second small diameter portion 64 that face each other in the radial direction.

[0029] In the exemplary embodiment shown in FIG. 1B, the second resin pipe 50 includes a flange 51 that is coupled to the pipe end 11 of the first resin pipe 10. The pipe end 11 of the first resin pipe 10 and the flange 51 of the second resin pipe 50 may be joined by fastening using a clip, for example.

[0030] The above-described plurality of fuel delivery pipes 1 (1A, 1B) having different specifications may include the first resin pipe 10 as a common component. Hereinafter, with reference to FIGS. 2 to 4B, the specific configuration of the first resin pipe 10 suitable as a common component for many types of fuel delivery pipes 1, and the fuel delivery pipe 1 including this first resin pipe 10 will be described.

[0031] Fig. 2 is a cross-sectional view of a first resin pipe 10 according to one embodiment. Fig. 3A is a perspective view of a fuel delivery pipe according to one embodiment. Fig. 3B is a cross-sectional view taken along line AA in Fig. 3A. Fig. 4A is a perspective view of a fuel delivery pipe according to another embodiment. Fig. 4B is a cross-sectional view taken along line BB in Fig. 4A. In the following description, elements common to the respective parts of the fuel delivery pipe 1 described above with reference to FIGS. 1A and 1B are denoted by the same reference numerals, and description thereof will be omitted.

[0032] In some embodiments, as shown in FIG. 2, the first resin pipe 10, which is a common component for various types of fuel delivery pipes 1, has a first large diameter portion 22 located closer to the pipe end 11 than the first small diameter portion 24, and the distance L' from the first step 28 to the pipe end 11 is greater than the inner diameter D1 of the first large diameter portion 22. 2 shows the first resin pipe 10 in a state before being assembled into the fuel delivery pipe 1. Therefore, depending on the manner in which the first resin pipe 10 is joined to the cap 40 or the second resin pipe 50, the distance L from the first step 28 to the pipe end 11 when assembled into the finished fuel delivery pipe 1 may not coincide with the distance L' shown in FIG. 2. For example, when the first resin pipe 10 and the cap 40 are joined by welding, the distance L from the first step 28 to the pipe end 11 in the finished fuel delivery pipe 1 may be slightly smaller than the distance L' shown in FIG. 2.

[0033] 2, the inner wall 20 of the first resin pipe 10 includes a tapered surface 29 as part of the large-diameter peripheral wall 23 that defines the first large-diameter portion 22 that opens at the pipe end 11. The tapered surface 29 serves to guide the tip portion 60 of the second resin pipe 50. 2, when the large diameter peripheral wall 23 includes a tapered surface 29, the inner diameter of the first large diameter portion 22 depends on the axial position. In this specification, the inner diameter D1 of the first large diameter portion 22 refers to the inner diameter of the first large diameter portion 22 at the connection point between the first step 28 and the large diameter peripheral wall 23.

[0034] 2, a first resin pipe 10, which is a common component for various types of fuel delivery pipes 1, includes an annular protrusion 30 provided at a pipe end 11, and an outer annular groove 32 and an inner annular groove 34 provided on either side of the annular protrusion 30 in the radial direction. The outer annular groove 32 and the inner annular groove 34 have the function of receiving molten resin when a cap 40 is welded to the pipe end 11 of the first resin pipe 10. The annular protrusion 30 is provided in a ring shape along the periphery of the opening of the first large diameter portion 22 of the first fuel flow passage 12 at the pipe end 11, protruding from the pipe end 11 in the axial direction of the first resin pipe 10. The outer annular groove 32 is an annular recess provided in the pipe end 11 so as to be located on the outer circumferential side of the annular protrusion 30. The outer annular groove 32 is formed between the annular protrusion 30 and an outer annular protrusion 33 located radially outer than the annular protrusion 30. The outer annular protrusion 33 is provided in the flange portion of the first resin pipe 10 at the pipe end 11. The inner annular groove 34 is an annular recess provided in the pipe end 11 so as to be located on the inner circumferential side of the annular protrusion 30. The inner annular groove 34 is formed between the annular protrusion 30 and an inner annular protrusion 35 located radially inner than the annular protrusion 30. The inner annular protrusion 35 defines the periphery of the opening at the pipe end 11 of the hollow portion 13 (first large diameter portion 22) of the first resin pipe 10. The protruding length of the annular protrusion 30 is greater than the protruding lengths of the outer annular protrusion 33 and the inner annular protrusion 35.

[0035] 2, the first resin pipe 10 includes a first support 18 for fixing and supporting the fuel delivery pipe 1. The first support 18 may protrude in the direction opposite to the inlet port 14 from a portion of the outer circumferential surface of the first resin pipe 10 on the side opposite to the inlet port 14. The first support 18 may be provided at an axial position between two adjacent first communication ports 16 and at a circumferential position opposite the inlet port 14, protruding from the outer surface of the first resin pipe 10 in the direction opposite the inlet port 14.

[0036] When the first resin pipe 10 having the above configuration is used alone, it is possible to realize the fuel delivery pipe 1C shown in Figures 3A and 3B, and when it is used in combination with the second resin pipe 50, it is possible to realize the fuel delivery pipe 1D shown in Figures 4A and 4B.

[0037] The fuel delivery pipe 1C shown in FIGS. 3A and 3B can be manufactured by welding a cap 40 to the pipe end 11 of the first resin pipe 10. In the fuel delivery pipe 1C, the outer annular groove 32 and the inner annular groove 34 of the pipe end 11 are at least partially filled with molten and solidified resin 36. In the first large diameter portion 22 of the hollow portion 13 of the first resin pipe 10, no parts other than the first resin pipe 10 and the cap 40 are present between the step surface of the first step 28 and the inner end face 41 of the cap 40. The first fuel flow path 12 is sealed at the joint (welded portion) between the inner end face 41 of the cap 40 and the pipe end 11 of the first resin pipe 10.

[0038] The fuel delivery pipe 1D shown in FIGS. 4A and 4B can be manufactured by fitting the tip portion 60 of the second resin pipe 50 into the hollow portion 13 (first large diameter portion 22) of the first resin pipe 10. In the fuel delivery pipe 1D, the pipe end 11 of the first resin pipe 10 has the same structure as that shown in Fig. 2, and the first resin pipe 10 has an annular protrusion 30, an outer annular groove 32, and an inner annular groove 34. This is in contrast to the fuel delivery pipe 1C, in which the pipe end 11 of the first resin pipe 10 is deformed by welding to the cap 40, and the outer annular groove 32 and the inner annular groove 34 are filled with resin 36. The first fuel flow path 12 and the second fuel flow path 52 are sealed by a seal ring 70. The seal ring 70 is held in an axial position between the first step 28 and the second step 66, and in a radial position between a region of the large-diameter circumferential wall 23 closer to the first step 28 than the tapered surface 29 and the second small-diameter portion 64.

[0039] 4A and 4B, the second resin pipe 50 includes a second support 58 for fixing and supporting the fuel delivery pipe 1D. The second support 58 may be provided to protrude from the end of the second resin pipe 50 opposite the tip end portion 60 in a direction intersecting the axial direction of the second resin pipe 50.

[0040] Next, a throttle device including the fuel delivery pipe 1 (1A to 1D) according to the above embodiment will be described. FIG. 5 is a perspective view of a throttle device according to one embodiment. In some embodiments, as shown in the figure, a throttle device 200 includes a fuel delivery pipe 1 (1A to 1D), a throttle body (210, 220) having an intake passage 201, a throttle valve 202 arranged in the intake passage 201, and a fuel injector 100 for injecting fuel into the intake passage 201. The fuel delivery pipe 1 (1A to 1D) is attached to the throttle body (210, 220) via a first support 18 and a second support 58. The throttle body (210, 220) is provided with intake passages 201 in a number corresponding to the number of cylinders of the engine. In the exemplary embodiment shown in FIG. 5, three sets of throttle valves 202 and fuel injectors 100 are provided corresponding to the three intake passages 201, respectively. The fuel injector 100 is configured to inject fuel supplied from a fuel delivery pipe 1 (1A to 1D) into an intake passage 201 downstream of a throttle valve 202.

[0041] 5, the throttle device 200 includes a fuel delivery pipe 1D that combines a first resin pipe 10 and a second resin pipe 50. The throttle bodies (210, 220) include a first throttle body 210 that corresponds to the first resin pipe 10 and a second throttle body 220 that corresponds to the second resin pipe 50. The first throttle body 210 and the second throttle body 220 are connected to each other by a fastening bolt 212. The throttle device 200 includes a motor 230 for driving the throttle valve 202, and a power transmission mechanism 240 for transmitting the driving force of the motor 230 to the throttle valve 202. The power transmission mechanism 240 includes a plurality of gears and a gear casing that houses the plurality of gears. The casing of the motor 230 and the gear casing of the power transmission mechanism 240 may be provided integrally with the second throttle body 220.

[0042] The characteristic configurations of the fuel delivery pipe 1 (1A to 1D) and the throttle device 200 according to the above-described embodiments can be summarized as follows.

[0043] [1] The fuel delivery pipe (1; 1A to 1D) according to at least some embodiments of the present invention is A fuel delivery pipe (1; 1A to 1D) for supplying fuel to at least one fuel injector (100), a first resin pipe (10) having a first fuel flow path (12) through which fuel flows, an inlet port (14) for taking in fuel into the first fuel flow path (12), and one or more first communication ports (16) for communicating the first fuel flow path (12) with one or more fuel injectors (100); The hollow portion (13) of the first resin pipe (10) forming the first fuel flow path (12) is a first large diameter portion (22) that opens at one pipe end (11) of the first resin pipe (12); a first small diameter portion (24) that is located closer to the center of the first resin pipe (10) than the first large diameter portion (22) and has a smaller diameter than the first large diameter portion (22); Including, an inner wall (20) of the first resin pipe (10) defining the hollow portion (13) includes a first step (28) provided at a position between the first large diameter portion (22) and the first small diameter portion (24); The distance L from the first step (28) to one pipe end (11) of the first resin pipe (10) is greater than the inner diameter D1 of the first large diameter portion (22).

[0044] According to the configuration [1] above, the inner wall 20 of the first resin pipe 10 has a first step 28 located between the first small diameter portion 24 and the first large diameter portion 22. Therefore, when the tip portion 60 of the other resin pipe 50 is fitted to the end of the hollow portion 13, a seal ring retaining space can be formed by utilizing the first step 28 and the first large diameter portion 22. Furthermore, because the distance L from the first step 28 to the pipe end 11 of the first resin pipe 10 is greater than the inner diameter D1 of the first large diameter portion 22, when the tip portion 60 of the other resin pipe 50 is fitted to the end of the hollow portion 13, the first resin pipe 10 and the other resin pipe 50 can be reliably supported by the first resin pipe 10 while maintaining their concentricity. On the other hand, since the first large diameter portion (22) of the first resin pipe (10) is located closer to the pipe end (11), when realizing a fuel delivery pipe (1; 1A, 1C) using the first resin pipe (10) alone, the end of the first fuel flow path (12) can be easily closed with a cap (40). In this way, by using the first resin pipe (10) alone or in combination with another resin pipe (50), it is possible to accommodate a variety of product specifications having different numbers of fuel injectors (100). Specifically, by using the first resin pipe (10) alone, it is possible to realize a fuel delivery pipe (1; 1A, 1C) capable of supplying fuel to the same number of fuel injectors (100) as the number of first communication ports (16). On the other hand, by fitting the tip portion (60) of the second resin pipe (50) having one or more second communication ports (56) into the hollow portion (13) of the first resin pipe (10), it is possible to realize a fuel delivery pipe (1; 1B, 1D) capable of supplying fuel to the same number of fuel injectors (100) as the total number of the first communication ports (16) and the second communication ports (56). In either case, the same mold can be used to mold the first resin pipe (10), so that a wide variety of fuel delivery pipes (1; 1A to 1D) having different numbers of fuel injectors (100) can be manufactured at low cost.

[0045] [2] In some embodiments, in the configuration of [1] above, The distance L from the first step 28 to one pipe end 11 of the first resin pipe 10 is 1.3 times or more the inner diameter D1 of the first large diameter portion 22.

[0046] According to the configuration [2] above, the distance L from the first step (28) to the pipe end (11) of the first resin pipe (10) is sufficiently large compared to the inner diameter D1 of the first large diameter portion (22). Therefore, when the tip portion (60) of the other resin pipe (50) is fitted to the end portion of the hollow portion (13), the concentricity of the first resin pipe (10) and the other resin pipe (50) is more effectively maintained, and the other resin pipe (50) can be reliably supported by the first resin pipe (10).

[0047] [3] In some embodiments, in the configuration of [1] or [2] above, Fuel delivery pipe (1; 1A, 1C) a cap (40) connected to one pipe end (11) of the first resin pipe (10) so as to close an opening of the first large diameter portion (22) of the hollow portion (13); At least the first step (28) of the inner wall (20) of the first resin pipe (10) faces the cap (40) across the first fuel flow path (12), The first fuel flow path (12) is sealed at the joint between the cap (40) and the first resin pipe (10).

[0048] According to the above configuration [3], by closing the hollow portion (13) of the first resin pipe (10), which is a common part for various types of fuel delivery pipes (1; 1A to 1D), with the cap (40), it is possible to easily obtain a fuel delivery pipe (1; 1A, 1C) that can supply fuel to the same number of fuel injectors (100) as the number of first communication ports (16).

[0049] [4] In some embodiments, in the configuration of [1] or [2] above, The fuel delivery pipe (1; 1B, 1D) is configured to supply fuel to a plurality of fuel injectors (100), the fuel delivery pipe (1; 1B, 1D) includes a second resin pipe (50) having a second fuel flow path (52) through which fuel flows and one or more second communication ports (56) that communicate the second fuel flow path (52) with one or more fuel injectors (100); The tip portion (60) of the second resin pipe (50) is fitted into the first large diameter portion (22) that opens into one pipe end (11) of the first resin pipe (10) so that the first fuel flow path (12) and the second fuel flow path (52) communicate with each other.

[0050] According to the configuration [4], by fitting the tip portion (60) of the second resin pipe (50) into the first large diameter portion (22) of the first resin pipe (10), which is a common part for various types of fuel delivery pipes (1; 1A to 1D), it is possible to easily obtain a fuel delivery pipe (1; 1B, 1D) capable of supplying fuel to the same number of fuel injectors (100) as the total number of the first communication ports (16) and the second communication ports (56).

[0051] [5] In some embodiments, in the configuration of [4] above, The tip portion (60) of the second resin pipe (50) is a second small diameter portion (64); a second large diameter portion (62) located closer to the base end of the second resin pipe (50) than the second small diameter portion (64) and having an outer diameter larger than that of the second small diameter portion (64); a second step (66) provided between the second small diameter portion (64) and the second large diameter portion (62); Including, The fuel delivery pipe (1; 1B, 1D) is provided with a seal ring (70) that is held in an axial position between the first step (28) and the second step (66) and in a radial position between a large-diameter peripheral wall (23) that defines a first large-diameter portion (22) of an inner wall (20) of the first resin pipe (10) and a second small-diameter portion (64).

[0052] According to the above configuration [5], the connection between the first resin pipe (10) and the second resin pipe (50) is sealed by the seal ring (70), thereby preventing fuel from leaking from the first fuel flow path (12) and the second fuel flow path (52).

[0053] [6] In some embodiments, in the configuration of [4] or [5] above, The first resin pipe (10) an annular protrusion (30) provided on one pipe end (11) along the periphery of the opening of the first large diameter portion (22); an outer annular groove (32) provided on one pipe end (11) on the outer circumferential side of the annular protrusion (30); an inner annular groove (34) provided on one pipe end (11) on the inner circumferential side of the annular protrusion (30); It has.

[0054] In the fuel delivery pipe (1; 1B, 1D), the tip portion (60) of the second resin pipe (50) is fitted into the hollow portion (13) of the first resin pipe (10), so there is no need to attach a cap (40) to the pipe end (11) of the first resin pipe (10). Therefore, the annular protrusion (30), the outer annular groove (32), and the inner annular groove (34) provided on the pipe end (11) of the first resin pipe (10) for proper welding to the cap (40) are essentially unnecessary for the fuel delivery pipe (1; 1B, 1D), and it is possible to perform processing to remove these. In the configuration [6] above, the structure (30, 32, 34) of the pipe end (11) of the first resin pipe (10) for proper welding to the cap (40) is left as it is without being removed, thereby making it possible to suppress the increase in costs associated with additional processing.

[0055] [7] In some embodiments, in any of the configurations [1] to [6] above, The first resin pipe (10) has two first communication ports (16).

[0056] Generally, fuel delivery pipes are used to distribute and supply fuel to two or more fuel injectors, so it is sufficient to consider a fuel delivery pipe specification as a product group that can supply fuel to two or more fuel injectors. In this regard, according to the configuration [7], the first resin pipe (10) has two first communication ports (16), and therefore, when the first resin pipe (10) is used alone, it is possible to realize a fuel delivery pipe (1; 1A, 1C) that supplies fuel to two fuel injectors.

[0057] [8] In at least some embodiments of the present invention, the throttle device (200) comprises: A fuel delivery pipe (1; 1A to 1D) having any of the configurations [1] to [7] above; a throttle body (210, 220) to which a fuel delivery pipe (1; 1A to 1D) is attached and which has an intake passage (201); a throttle valve (202) disposed in each of the intake passages (201) of the throttle bodies (210, 220); a fuel injector (100) for injecting fuel into an intake passage (201) downstream of the throttle valve (202); Equipped with The fuel injector (100) is configured to inject fuel supplied from a fuel delivery pipe (1; 1A to 1D) into an intake passage (201).

[0058] According to the configuration [8], as described in [1] above, by using the first resin pipe (10) alone or in combination with another resin pipe (50), it is possible to accommodate a plurality of product specifications having different numbers of fuel injectors (100). Therefore, a wide variety of throttle devices (200) can be manufactured at low cost. [Explanation of symbols]

[0059] 1(1A~1D): Fuel delivery pipe 10: First resin pipe 11: Pipe end 12: First fuel flow path 13: Hollow part 14: Inlet port 16: First communication port 20:Inner wall 22: First large diameter section 23: Large diameter wall 24: 1st small diameter section 28: First step 30: Annular convex part 32:Outer annular groove 34: Inner annular groove 40: Cap 50: Second resin pipe 52: Second fuel flow path 56: Second communication port 60:Tip 62: Second large diameter section 64:Second small diameter section 66: Second step 70: Seal ring 100: Fuel injector 200: Throttle device 201: Intake passage 202: Throttle valve

Claims

1. A fuel delivery pipe for supplying fuel to at least one fuel injector, a first resin pipe including a first fuel flow path through which the fuel flows, an inlet port for taking the fuel into the first fuel flow path, and one or more first communication ports for communicating the first fuel flow path with one or more of the fuel injectors; The hollow portion of the first resin pipe forming the first fuel flow path is a first large diameter portion that opens at one pipe end of the first resin pipe; a first small diameter portion located closer to a center of the first resin pipe than the first large diameter portion and having a smaller diameter than the first large diameter portion; Including, an inner wall of the first resin pipe defining the hollow portion includes a first step provided at a position between the first large diameter portion and the first small diameter portion, A distance L from the first step to the one pipe end of the first resin pipe is greater than an inner diameter D1 of the first large diameter portion. Fuel delivery pipe.

2. A distance L from the first step to the one pipe end of the first resin pipe is 1.3 times or more the inner diameter D1 of the first large diameter portion. The fuel delivery pipe according to claim 1 .

3. a cap connected to the one pipe end of the first resin pipe so as to close an opening of the first large diameter portion of the hollow portion, at least the first step of the inner wall of the first resin pipe faces the cap across the first fuel flow path, The first fuel flow path is sealed at a joint between the cap and the first resin pipe.

3. The fuel delivery pipe according to claim 1 or 2.

4. the fuel delivery pipe is configured to supply the fuel to the plurality of fuel injectors, a second resin pipe having a second fuel flow path through which the fuel flows and one or more second communication ports that communicate the second fuel flow path with one or more of the fuel injectors; The tip end of the second resin pipe is fitted into the first large diameter portion that opens at the one pipe end of the first resin pipe so that the first fuel flow path and the second fuel flow path communicate with each other.

3. The fuel delivery pipe according to claim 1 or 2.

5. The tip portion of the second resin pipe is A second small diameter portion; a second large diameter portion located closer to the base end of the second resin pipe than the second small diameter portion and having an outer diameter larger than that of the second small diameter portion; a second step provided between the second small diameter portion and the second large diameter portion; Including, a seal ring that is held in an axial position between the first step and the second step and in a radial position between a large-diameter peripheral wall that defines the first large-diameter portion of the inner wall of the first resin pipe and the second small-diameter portion; The fuel delivery pipe according to claim 4.

6. The first resin pipe is an annular protrusion provided on the one pipe end along a periphery of the opening of the first large diameter portion; an outer annular groove provided on the one pipe end on the outer circumferential side of the annular protrusion; an inner annular groove provided in the one pipe end on the inner circumferential side of the annular protrusion; have The fuel delivery pipe according to claim 4.

7. The first resin pipe has two first communication ports.

3. The fuel delivery pipe according to claim 1 or 2.

8. The fuel delivery pipe according to claim 1 or 2; a throttle body to which the fuel delivery pipe is attached and which has an intake passage; a throttle valve disposed in each of the intake passages of the throttle body; a fuel injector for injecting the fuel into the intake passage downstream of the throttle valve; Equipped with The fuel injector is configured to inject the fuel supplied from the fuel delivery pipe into the intake passage. Throttle device.

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