JP5759788B2 - Manufacturing method of fuel delivery pipe - Google Patents

Description

  The present invention relates to a technique for fixing an injector socket to a fuel delivery pipe.

  Conventionally, in an internal combustion engine or the like, a fuel delivery pipe (hereinafter referred to as “delivery pipe”) that distributes fuel supplied from a fuel supply pipe to injectors provided in each cylinder has been used (for example, patents). Reference 1). A branch hole is formed in the outer periphery of the delivery pipe, and fuel is distributed from the delivery pipe to the injector by connecting the branch hole to the injector through a connecting member such as an injector socket.

JP 2005-147075 A

The injector socket is fixed to the delivery pipe by brazing or welding. For this reason, thermal distortion occurs, and it is difficult to ensure the accuracy of the mounting position of the injector socket.
The present invention has been completed based on the above-described circumstances, and provides a technique for suppressing the occurrence of thermal strain and ensuring the positional accuracy of the injector socket by eliminating brazing and welding. There is.

  The present invention is a fuel delivery pipe comprising a main pipe having a fuel passage formed therein and an injector socket for mounting an injector, wherein an attachment hole is formed in an outer peripheral wall of the main pipe, and the injector socket Is characterized in that a cylindrical mounting portion that is press-fitted into the mounting hole is formed.

  The present invention is a method of manufacturing a fuel delivery pipe in which an injector socket is fixed to a main pipe having a fuel passage formed therein, and is formed in the injector socket with respect to a mounting hole formed in the main pipe. It is characterized in that it includes a press-fitting step for press-fitting a cylindrical mounting portion.

The following configuration is preferable as an embodiment of the present invention.
-Crimp (clamp) the tip of the mounting portion from the inside with respect to the mounting hole. If it does in this way, an attaching part can be certainly fixed to an attachment hole.

-Fill the concave part formed in the base end part of the said attaching part with the sealing material which seals between the hole edge parts of the said attaching hole. If it does in this way, it will become possible to seal between the hole edge part and attachment part of an attachment hole reliably.

  According to the present invention, when the injector socket is attached to the fuel delivery pipe, no heat load such as heating is applied, so that the injector socket and the fuel delivery pipe are not thermally distorted. Therefore, it is possible to increase the positional accuracy (mounting accuracy) of the injector socket with respect to the fuel delivery pipe.

The figure which shows the structure of the fuel supply apparatus in this embodiment in embodiment. Top view of fuel delivery pipe Sectional view showing the injector socket mounting structure Diagram showing fuel delivery pipe manufacturing process Diagram showing fuel delivery pipe manufacturing process Diagram showing fuel delivery pipe manufacturing process Diagram showing fuel delivery pipe manufacturing process The figure which expanded the A section of FIG.

1. Configuration of Fuel Supply Device in Automobile FIG. 1 is an explanatory diagram showing a configuration of a fuel supply device 50 in the present embodiment. The fuel supply device 50 is mounted on the body of the automobile 20 and supplies fuel from the fuel tank 30 to the engine 40. The fuel supply device 50 includes a fuel supply pump 52, a filter 54, a pressure adjustment device 56, a fuel transfer pipe P 1, a fuel supply pipe P 2, a fuel return pipe P 3, and a fuel delivery pipe 60.

  The fuel supply pump 52 pressurizes the fuel inside the fuel tank 42. The pressurized fuel is transferred from the fuel tank 42 to the engine 40 through the fuel transfer pipe P1. The transferred fuel is filtered by the filter 54 and sent to the fuel supply pipe P <b> 2 via the pressure adjusting device 56. The pressure of the fuel when being supplied to the fuel supply pipe P <b> 2 is adjusted by the pressure adjusting device 56. The fuel sent to the fuel supply pipe P2 is sent to the fuel delivery pipe 60 connected to the fuel supply pipe P2, and then branched in the fuel delivery pipe and supplied to a plurality of injectors (not shown). Then, by opening the on-off valve of each injector, fuel is injected into each cylinder in the engine 40 via a supply pipe connected to each injector. The remaining fuel is returned to the fuel tank 42 through the fuel return pipe P3.

2. Configuration of Fuel Delivery Pipe 60 As shown in FIG. 2, the fuel delivery pipe 60 includes a straight main pipe 70 that is long in one direction. The main pipe 70 is made of, for example, a stainless steel pipe material, and a fuel passage U is formed therein. A plurality of mounting bosses B are attached to the main pipe 70 in the pipe axis direction. A plurality of flat seat surfaces 74 are formed on the outer peripheral surface of the main pipe 70 at regular intervals. A mounting hole 75 is formed on each flat seat surface 74. The mounting hole 75 penetrates the outer peripheral wall of the main pipe 70 vertically and communicates with the inside of the main pipe 70. The injector socket 80 is attached by press-fitting and attaching the attachment portion 85 to the attachment hole 75. Further, the mounting hole 75 is chamfered 76 to enhance the insertion property of the mounting portion 85.

  The injector socket 80 is a socket for attaching an injector, and has a structure in which an attachment portion 85 is integrally formed on the bottom surface of the socket body 81. The socket body 81 receives and holds the tip of the injector, and has a cylindrical shape whose upper surface opens as a receiving port for the injector.

  The attachment portion 85 is formed at the center of the bottom surface of the socket body 81 and has a cylindrical shape that is slightly smaller than the socket body 81. As shown in FIG. 4, the attachment portion 85 includes a body portion (a range indicated by a dimension C in FIG. 4) 86 and a first taper portion 87. The outer diameter of the body portion 86 is set to be slightly larger than the hole diameter of the mounting hole 75 on the fuel delivery pipe 60 described above, and is configured to be press-fitted into the mounting hole 75. The first taper portion 87 is formed on the proximal end side of the body portion 86 and has a shape that increases in diameter toward the socket body 81. The first taper portion 87 is pushed into the attachment hole 75 while plastically deforming the attachment hole 75, and is in close contact with the inner periphery of the attachment hole 75 over the entire circumference, and the adhesion of the attachment portion 85 to the attachment hole 75. Fulfills the function of enhancing.

  Further, a second taper portion 86A is formed at the inner peripheral tip (lower end in FIG. 4) of the body portion 86. As shown in FIG. 4, the second taper portion 86 </ b> A is inclined so that the diameter of the inner periphery of the trunk portion becomes smaller toward the tip (lower end in FIG. 4). In the present embodiment, the tip end of the attachment portion 85 is caulked with respect to the attachment hole 75 of the main pipe 70 by plastically deforming the second tapered portion 86A side so as to spread from the inside to the outside. As described above, in the present embodiment, the injector socket 80 is fixed to the socket body 81 by press-fitting the attachment portion 85 into the attachment hole 75 and caulking the tip.

  The outer shape of the body portion 86 is generally straight, that is, the outer diameter is the same as the overall height (indicated by the dimension C in FIG. 4), and the thickness of the tip portion where the second taper portion 86A is formed. However, it is thicker than the other parts. With such a configuration, the tip of the body portion 86 is easily applied to the attachment hole 75 when crimped, so that the attachment portion 85 can be firmly crimped to the attachment hole 75.

  A concave portion 88 is formed at the base end of the mounting portion 85 over the entire circumference. The concave portion 88 has a concave shape that bulges upward from the bottom surface of the socket main body 81 in FIG. 4, and is a seal material (highly viscous liquid that seals between the hole edges of the mounting holes 75 inside. Gasket) 89 is filled. The mounting portion 85 described above penetrates in the vertical direction, and functions as a passage for introducing fuel from the main pipe 70 to the injector side.

  A pipe connector 61 </ b> A for connecting the fuel supply pipe P <b> 2 to the main pipe 61 is provided on one end side in the axial direction of the main pipe 61. On the other hand, a pressure sensor connector 61B is connected to the other end 61B of the main pipe 61.

3. Manufacturing method of fuel delivery pipe 60 (Installation method of injector socket 80 to main pipe 70)
In order to attach the injector socket 80 to the main pipe 70, first, the sealing material 89 is applied to the concave portion of the injector socket 80. Thereafter, the injector socket 80 is positioned with the attachment portion 85 facing downward with respect to the attachment hole 75 formed in the main pipe 70.

  After the positioning, using the jig 100, the socket body 81 of the injector socket 80 is pushed into the main pipe side (lower side in FIG. 4). Specifically, the socket body 81 is pushed in using the jig 100 until the bottom surface abuts against the flat seat surface 74 of the main pipe 70. As a result, the mounting portion 85 of the injector socket 80 is press-fitted into the mounting hole 75 of the main pipe 70 (press-fitting step: FIGS. 4 and 5).

  In the present embodiment, the first taper portion 87 formed in the attachment portion 85 is pushed into the hole while plastically deforming the inner peripheral wall of the attachment hole 75 when the jig 100 is press-fitted. The taper portion 87 is in close contact with the hole wall of the mounting hole 75 all around. For this reason, the attachment portion 85 can be firmly attached to the attachment hole 75. Further, after the press-fitting, the attachment portion 85 passes through the attachment hole 75 and the tip protrudes inside the main pipe 70.

  Next, the punch 110 is inserted through the attachment portion 85 press-fitted into the attachment hole 75 to penetrate the attachment portion 85. The outer shape of the punch 110 is a size that fits into the body portion 86 of the attachment portion 85 without a gap. Therefore, when the punch 110 is penetrated, the second taper portion 86 </ b> A formed at the inner peripheral tip of the mounting portion 85 is plastically deformed so as to be spread outward by the punch 110. Thus, the tip of the attachment portion 85 can be crimped from the inside with respect to the attachment hole 75 (caulking step: FIGS. 6 to 8).

  Thus, the mounting portion 85 can be fixed to the mounting hole 75 of the main pipe 70 by press-fitting and caulking, and the injector socket 80 can be firmly fixed to the main pipe 70 without rattling. In the present embodiment, all four injector sockets 80 are assembled to the main pipe 70 at a time by simultaneously performing the press-fitting step and the caulking step on the four injector sockets 80 attached to the main pipe 70.

4). Explanation of Effects According to the present embodiment, when the injector socket 80 is attached to the fuel delivery pipe 60, no heat load such as heating is applied, that is, the injector socket 80 is assembled to the main pipe 70 by press fitting or caulking instead of welding or brazing. Since the fixing is performed, the injector socket 80 and the fuel delivery pipe 60 are not thermally distorted or can be suppressed. Therefore, the positional accuracy (attachment accuracy) of the injector socket 80 relative to the fuel delivery pipe 60 can be increased.

  In the present embodiment, the first tapered portion 87 is formed in the attachment portion 85 so as to be in close contact with the attachment hole 75, and the concave portion 88 formed at the base end of the attachment portion 85 is filled with the sealing material 89 and attached. The gap between the hole edge of the hole 75 and the attachment portion 85 is sealed. By doing so, it is possible to reliably seal between the hole edge portion of the attachment hole 75 and the attachment portion 85, so that fuel leakage from the attachment hole 75 can be prevented.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.

  (1) In the above embodiment, the four injector sockets 80 are collectively assembled to the main pipe 61, that is, the press-fitting step and the caulking step are simultaneously performed on the four injector sockets. You may make it perform.

60 ... Fuel delivery pipe 70 ... Main pipe 74 ... Flat seat surface 75 ... Mounting hole 80 ... Injector socket 81 ... Socket body 85 ... Mounting part 86 ... Body 86A・ Second taper part 87 ・ ・ ・ First taper part

Claims (2)

A fuel delivery pipe manufacturing method in which an injector socket is fixed to a main pipe having a fuel passage formed therein,
A mounting hole is formed through the outer peripheral wall of the main pipe,
The injector socket has a cylindrical mounting portion that is press-fitted into the mounting hole.
The mounting portion comprises a first taper portion on the injector socket side and a body portion on the insertion direction side,
The first taper portion has a shape that expands toward the injector socket side,
The body has a straight outer shape,
The front end in the insertion direction of the body portion is a second taper portion having a shape in which the thickness increases so that the diameter of the inner periphery decreases in the insertion direction,
To the mounting hole formed in the main pipe, said After inserting the barrel portion of the mounting portion of the cylindrical formed in the injector socket, while the first tapered portion by plastically deforming the mounting hole A press-fitting step for press-fitting to push in ;
By inserting a jig into the mounting portion press-fitted into the mounting hole, and plastically deforming the second tapered portion formed in the mounting portion so as to spread from the inside to the outside, A caulking step for caulking the tip in the insertion direction from the inside with respect to the mounting hole;
A method for producing a fuel delivery pipe, comprising: 2. The method for producing a fuel delivery pipe according to claim 1, wherein, in the press-fitting step, the attachment portion in which a concave portion formed at a base end of the attachment portion is filled with a sealing material is press-fitted into the attachment hole. .

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