JPH0590078U - Pipe fitting device - Google Patents

Abstract

(57) [Summary] [Purpose] The main purpose of the present invention is to improve the sealing property of the connecting portion between the pipe body and the base structure. [Composition] A pipe joint device 10 includes a tubular member 22 fixed to a tubular body 20, and a sleeve nut 23 provided on the outside of the tubular member 22 so as to be relatively rotatable. The female screw 1 is provided on the inner peripheral portion of the receiving hole 13 provided in the base structure 11.
4 are formed. The sleeve nut 23 has an internal thread 14
It has a male screw 36 to be screwed in and a center hole 40. The tubular member 22 includes a cylindrical portion 30, a flange portion 31, and a guide tapered surface 32. Guide taper surface 32
Is provided at the connecting portion between the cylindrical portion 30 and the flange portion 31. When the sleeve nut 23 is tightened, the opening edge 41 of the center hole 40 is brought into contact with the guide taper surface 32, thereby forming a tapered seat surface. Tip sealing surface 26 for 16
I'm trying to center it.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a pipe joint device applied to, for example, a connecting portion of an injection pipe used in a fuel supply system of an internal combustion engine.

[0002]

[Prior Art]

 In a fuel supply system of an internal combustion engine, for example, as shown in FIG. 3, when a pipe body 101 such as an injection pipe is connected to a base structure 100 such as a fuel pressure accumulator chamber, a receiving hole 102 provided in the base structure 100. The intermediate connector 104 is screwed into the female screw 103, and the tube body 101 is connected through the intermediate connector 104. In this case, a tubular member 105 made of a hard material is fixed to the end of the tubular body 101, and a sleeve nut 106 is rotatably provided outside the tubular member 105. Then, the female screw 110 provided on the sleeve nut 106 is screwed to a predetermined position of the male screw 111 provided on the intermediate connector 104, so that the tip sealing surface 112 of the pipe body 101 is brought into contact with the tapered seat surface 113 of the intermediate connector 104. I try to make them closely.

In the above-mentioned conventional example, since the intermediate connector 104 is used, the protruding position of the tubular body 101 with respect to the base structure 100 is increased by the length of the intermediate connector 104. Therefore, if there is no space above the base structure 100, the pipe body 101 will interfere with the surrounding materials. Further, since the intermediate connector 104 is required, the number of parts is increased, and there is a problem in that more parts are required to be sealed.

Therefore, the present inventors have proposed a joint structure for connecting the pipe body 101 without using the intermediate connector 104. As shown in FIG. 4, a sleeve nut 120 is rotatably attached to the outside of a tubular member 105 fixed to the end of a tubular body 101, and a male screw 121 provided on the sleeve nut 120 is It is adapted to be directly screwed into the female screw 103 of the base structure 100. In the case of this prior art, by tightening the sleeve nut 120, the tubular body 101 advances in the axial direction, so that as shown in FIG. 5, the tip sealing surface 112 of the tubular body 101 opens at the opening of the through hole 123. It closely contacts a taper-shaped seating surface 124 provided on the section.

[0005]

[Problems to be solved by the device]

 In the case of the above prior art, a gap ΔG exists between the inner surface 125 of the sleeve nut 120 and the outer peripheral surface of the tubular member 105 due to the difference between the inner diameter of the sleeve nut 120 and the outer diameter of the tubular member 105. Therefore, in the state before tightening the sleeve nut 120, the tubular member 105 is movable in the radial direction of the sleeve nut 120 (the direction of arrow A in the figure). Therefore, when the sleeve nut 120 is strongly tightened with the tubular member 105 and the tube body 101 eccentric as shown by the chain double-dashed line in FIG. 5, the tip seal surface 112 is disengaged from the taper seat surface 124. They will be closely attached while eccentric. Since the tubular body 101 is softer than the tapered seating surface 124, if it is strongly pressed in the eccentric state as described above, the leading end sealing surface 112 is deformed in the circumferential direction unevenly.

Therefore, when the pipe 101 is detached from the base structure 100 and then reconnected, the tip sealing surface 112 deformed by the previous connection is moved to a position different from the previous one, and the taper seat surface 124. May come into contact with. In this case, since it becomes difficult for the tapered seat surface 124 and the tip seal surface 112 to uniformly come into close contact with each other over the entire circumference, the sealing property is deteriorated in a high-pressure fluid such as a fuel injection pipe flowing through the pipe body 101. . Therefore, an object of the present invention is to provide a pipe joint device in which a good sealing property is ensured at a connecting portion between a pipe body and a base structure.

[0007]

[Means for Solving the Problems]

 The pipe joint device of the present invention developed to achieve the above object has a base hole having a receiving hole having an internal thread at the inner peripheral portion thereof, a through hole opening at the inner wall of the receiving hole, and a tapered seat surface. The tip has a tubular body having a tapered tip seal surface that is brought into close contact with the tapered seat surface, and a cylindrical portion fixed to the outer peripheral portion near the tip of the tubular body, and a flange on the tip side. And a sleeve nut having a center hole into which the cylindrical portion of the tubular member is inserted so that the cylindrical portion of the tubular member is relatively rotatably provided. The flange portion of the cylindrical member and the cylindrical portion are connected to each other, facing the opening edge of the center hole of the sleeve nut, and the outer diameter of the flange portion is larger than the inner diameter of the center hole and the cylindrical portion. The outer diameter of the side In which characterized in that a small guide tapered surface than the inner diameter of the serial center hole.

[0008]

[Action]

 Screw the male thread of the sleeve nut into the female thread of the receiving hole of the base structure, and tighten the sleeve nut in the direction to bring it into contact with the tapered seating surface inside the receiving hole of the tube. When the sleeve nut is thus threaded, its thrust acts on the pipe body via the tubular member. In this case, since the opening edge of the center hole of the sleeve nut rotates while sliding while being in contact with the guide taper surface of the tubular member, the center of the tubular member comes to the center of the sleeve nut, and the tip sealing surface The sleeve nut is tightened in the condition that the center of the Therefore, the tip seal surface and the tapered seat surface evenly contact each other in the circumferential direction.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. The pipe joint device 10 shown in FIGS. 1 and 2 includes a base structure 11 and a joint unit 12. The base structure 11 is, for example, a fuel pressure accumulating chamber (common rail) of the fuel supply system, but may be another structure. A receiving hole 13 is provided in the base structure 11. A female screw 14 is provided on the inner peripheral portion of the receiving hole 13. A fuel circulation hole 15 is opened in the inner wall 13 a of the receiving hole 13. A tapered seat surface 16 is formed at the opening of the flow hole 15. The angle θ1 (see FIG. 1) formed by the tapered seat surface 16 is, for example, 60 °.

The pipe joint unit 12 is provided with a tubular body 20 such as a fuel injection pipe, a tubular member 22 fixed near a tip end portion 21 of the tubular body 20, and rotatably provided outside the tubular member 22. The sleeve nut 23 is provided. The tubular body 20, the tubular member 22, and the sleeve nut 23 are all made of metal, but the tubular member 22 is made of a material harder than the tubular body 20. The base structure 11 is also made of a material harder than the tube body 20.

The tip end portion 21 of the tubular body 20 is expanded by applying a compressive load in the axial direction by an appropriate plastic working such as an up-setting process performed with the tubular member 22 set. And the wall thickness is locally increased. Along with this processing, the tip portion 21 is crimped and fixed to the inner surface of the tubular member 22. A frustoconical tip sealing surface 26 is provided on the end surface 25 side of the tubular body 20. The outer diameter of the end surface 25 is larger than the inner diameter of the flow hole 15.

The tip sealing surface 26 has a tapered shape whose outer diameter decreases toward the end surface 25. The angle θ2 formed by the sealing surface 26 is, for example, 58 °. A stopper wall 27 is provided at the base of the tip end portion 21 of the tubular body 20, and the stopper wall 27 prevents the tubular member 22 from coming off the tip end portion 21.

The tubular member 22 includes a cylindrical portion 30 fixed to the distal end portion 21 of the tubular body 20, and a flange portion 31 formed on the distal end side of the cylindrical portion 30. A guide taper surface 32, which will be described later, is formed over the entire circumference of the tubular member 22 at a connecting portion where the cylindrical portion 30 and the flange portion 31 are continuous.

The sleeve nut 23 includes a body 35 having a portion (not shown) into which a rotating tool such as a wrench is fitted, and a cylindrical portion 37 having a male screw 36. The male screw 36 has a size that can be screwed into the female screw 14 of the base structure 11. A center hole 40 is provided at the center of the sleeve nut 23 so as to penetrate in the axial direction. The inner diameter of the center hole 40 is larger than the outer diameter of the cylindrical portion 30 of the tubular member 22. Therefore, a gap G due to the dimensional difference Δd is generated between the cylindrical portion 30 and the sleeve nut 23. Therefore, the tubular member 22 can be moved in the radial direction relative to the sleeve nut 23 by twice the dimension difference Δd.

The above-mentioned tubular member 22 is provided with a truncated conical guide taper surface 32. The guide taper surface 32 is provided at a position where the cylindrical portion 30 of the tubular member 22 and the flange portion 31 are connected, that is, at a position facing the opening edge 41 of the center hole 40 of the sleeve nut 23. The outer diameter D1 of the guide taper surface 32 on the flange portion 31 side is larger than the inner diameter of the center hole 40 of the sleeve nut 23. The outer diameter D2 of the guide tapered surface 32 on the cylindrical portion 30 side is smaller than the inner diameter of the center hole 40. The opening edge 41 of the center hole 40 is subjected to corner chamfering at an angle similar to the inclination angle of the guide tapered surface 32.

Next, the operation of the pipe joint device 10 having the above configuration will be described. As shown in FIG. 2, the male screw 36 of the sleeve nut 23 is screwed onto the female screw 14 of the base structure 11, and the sleeve nut 23 is rotated in the tightening direction. By doing so, the opening edge 41 of the center hole 40 of the sleeve nut 23 is in contact with the guide tapered surface 32 of the tubular member 22, and the sleeve nut 23 rotates relatively. The tubular member 22 and the tubular body 20 move in the axial direction of the receiving hole 13 without rotating.

As described above, as the sleeve nut 23 is tightened, the opening edge 41 of the center hole 40 relatively rotates while sliding on the guide taper surface 32, so that the center of the tubular member 22 comes to the center of the sleeve nut 23. Like That is, centering of the tubular body 20 with respect to the sleeve nut 23 is automatically performed. In this state, the sleeve nut 23 is tightened with a predetermined torque, so that the tip sealing surface 26 of the tubular body 20 evenly contacts the taper seat surface 16 in the circumferential direction.

Since the base structure 11 is harder than the tubular body 20, the tip sealing surface 26 is evenly adhered over its entire circumference with some deformation. As a result, a perfect circular line contact state is maintained and good sealing properties are exhibited. Moreover, in this embodiment, since the angle θ2 formed by the tip seal surface 26 is smaller than the angle θ1 (60 °) formed by the tapered seat surface 16 by about 2 °, the tip seal surface 26 is tapered. It is pressed into a ring shape in good condition. According to the research conducted by the present inventors, it has been found that, as long as the difference between the angles θ1 and θ2 is in the range of 1 to 3 °, good sealability can be secured as in the above-mentioned embodiment.

The joint unit 12 can be detached from the base structure 11 by rotating the sleeve nut 23 in the opposite direction to the above. In the pipe coupling device 10 of the present embodiment, the tip sealing surface 26 is evenly pressed against the tapered seating surface 16 in the circumferential direction at the time of connection, so that the tip sealing surface 26 is deformed to some extent at the time of connection. However, the deformation is uniform in the circumferential direction of the tip sealing surface 26. Therefore, even if the joint unit 12 is detached from the base structure 11 and then connected to the base structure 11 again, the tip seal surface 26 can be brought into close contact with the tapered seat surface 16 evenly, and the fuel injection can be performed. Even in a case where a fluid having a high pressure flows through the tube body 20 such as a tube, a good sealing property is always ensured.

[0020]

[Effect of the device]

 According to the present invention, a good sealing property can be obtained at the connecting portion between the pipe body and the base structure.

[Brief description of drawings]

FIG. 1 is a sectional view of a pipe joint device showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a pipe body of the pipe joint device shown in FIG. 1 connected to a base structure.

FIG. 3 is a cross-sectional view showing a conventional pipe joint device.

FIG. 4 is a cross-sectional view of a pipe joint device showing another conventional example.

5 is a cross-sectional view showing a state in which pipes are connected in the conventional example shown in FIG.

[Explanation of symbols]

10 ... Pipe joint device, 11 ... Base structure, 12 ... Joint unit, 13 ... Receiving hole, 14 ... Female screw, 15 ... Flow hole,
16 ... Tapered seating surface, 20 ... Tube, 21 ... Tip of tube, 22 ... Cylindrical member, 23 ... Sleeve nut, 26 ... Tip sealing surface, 30 ... Cylindrical section, 31 ... Flange section, 32 ...
Guide taper surface, 40 ... Center hole, 41 ... Opening edge.

Claims (1)

[Scope of utility model registration request] 1. A base structure having a receiving hole having an internal thread on an inner peripheral portion thereof, a through hole opening at a rear wall of the receiving hole, and a tapered seating surface, and a tip end portion of the base structure being in close contact with the tapered seating surface. A tubular member having a tapered tip sealing surface, a cylindrical member having a cylindrical portion fixed to the outer peripheral portion near the distal end portion of the tubular member and having a flange portion on the distal end side, and a female screw of the receiving hole. And a sleeve nut having a center hole into which the cylindrical portion of the tubular member is inserted so that the cylindrical portion of the tubular member can be relatively rotatably inserted, and the flange portion of the tubular member and the cylindrical portion are continuous with each other, A guide taper surface facing the opening edge of the center hole of the sleeve nut, the outer diameter of the flange portion side being larger than the inner diameter of the center hole, and the outer diameter of the cylindrical portion side being smaller than the inner diameter of the center hole. Setting Pipe joint and wherein the a.