JPH0926067A - Pipe joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the connection of pipe joints and prevents a leakage caused by vibration by forming a conical surface of a flare section and an inner hole face like conical surface of a first joint member into a specific vertical angle and forming a diameter shrinking part like conical surface of an elastic fangle section into a specific vertical angle. SOLUTION: A first joint member A1 fitted in a first pipe P1 and a second joint member A2 fitted in a second pipe P2 are tightened by screw-fitting screws 13, 17, and a flare section 10 and a flange section 14 are held in pressure-contact between a tapered inner hole 12 of the first joint member A1 and an end 15 of the second joint member A2 to form a seal section. At this time, a vertical angle of a conical surface of the flare section 10 and a vertical angle of a face of the tapered inner hole 12 of the first joint member A1 are formed in approximately 90 degrees. Moreover, a vertical angle of a tapered diameter shrinking section 14b of the elastic flange section 14 is formed in 84+2 degrees. Consequently, it is possible to simplify the connection work of pipe joints by using the minimum number of parts without causing a leakage due to vibration.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint, and more particularly to a pipe joint suitable for use in automobile piping.

[0002]

2. Description of the Related Art Vehicles are provided with brake tubes, fuel pipes and the like.
As shown in Fig. 3, the multiple pipes P are clamps C for collective piping.
It is fixed to the car body by.

In the case of an FF vehicle, in particular, one brake tube is branched from a bundle of pipes into an L-shape as shown by P ', and X pipes are formed. Since the collective pipe for such X pipes has the tube P'which is projected to the side, it is bulky and inconvenient to handle during transportation and storage, and the transportation efficiency is lowered. It is not preferable because it requires a lot of storage space. Further, when the collective pipe is attached to the vehicle body, it is not easy to handle it due to the overhanging tube P '. In order to solve such a problem, it is conceivable that the overhanging tube P'is formed separately from the collective pipe and connected to the collective pipe by the pipe joint A after the assembly.

[0004]

However, conventionally, such a pipe joint has not been used so far, but the end portion of each pipe has been connected to the fixed portion as shown in FIG. I'm just there. That is, the flared portion F that spreads like a bosh at the end of the pipe P is only tightened at the tip of the tightening member D that is screwed into the hole of the fixed portion B to obtain the connected state. Further, even if it is intended to connect pipes branching from the middle of the collective pipe with a pipe joint, it is sufficiently resistant to vibration of the vehicle, the connection work is simple, the number of parts is small, and no leakage occurs. Pipe fitting development is required.

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems, and its purpose is to reduce the number of parts, to simplify the connection,
The purpose is to obtain a pipe joint that does not leak due to vibration.

[0006]

In order to achieve the above object, the pipe joint of the present invention is provided with an end portion of a first pipe to be connected,
Then, the flare portion formed so as to expand in a conical surface shape away from the axial direction and the end portion of the second pipe to be connected are expanded in diameter so as to form a step, and then the conical surface diameter is reduced. And an elastic flange portion formed as described above, and a conical inner surface that is fitted to the outer peripheral surface of the first tube and extends along the outer peripheral surface of the flare portion, and an internal thread is formed on an extension of the inner hole surface. A first joint member having a groove formed therein and a second joint member so as to come into contact with the step portion.
A second joint member that is fitted to the outer peripheral surface of the pipe and has an external thread that is screwed to the female thread on the outer peripheral surface.
Due to the mutual tightening of the second joint member and the second joint member, the flare portion and the elasticity are formed between the conical inner surface of the first joint member and the end surface of the second joint member that abuts the step. The flange portion and the conical-surface-reduced portion are pressed together, and the apex angle of the conical surface of the flare portion and the apex angle of the conical-surface-shaped inner hole surface of the first joint member are formed to be about 90 °. It is characterized in that the apex angle of the conical surface-reduced portion of the flange portion is formed to be 84 ± 2 °.

With the above structure, the first pipe is provided at the end of the first pipe.
Fitting the joint member, fitting the second joint member to the end of the second pipe, butting the first pipe and the second pipe, and screwing both joint members together to tighten the first pipe. The flare portion and the elastic flange portion of the second tube are pressed against each other, and both are elastically strongly contacted with each other to form a seal portion.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. The pipe joint A shown in FIG. 1 is configured as shown in FIG. The pipe joint A connects the first pipe P1 and the second pipe P2. Both pipes P1,
As a joint member that connects P2, the first joint member A1 is provided on the side of the first pipe P1, and the second joint member A2 is provided on the side of the second pipe P2.

A flare portion 10 is integrally formed at the tip of the first pipe P1. The flare portion 10 is formed by processing the end portion of the pipe P1 so that the diameter of the end portion of the pipe P1 increases in a conical surface shape as the end portion of the pipe P1 moves away from the end portion in the axial direction. Flare part 10
It is preferable to fold its leading edge inward to form a double structure, which is generally in the form of a morning glory flower.

The first joint member A1 has a substantially cylindrical shape, and an inner hole 11 slidably fitted on the outer periphery of the first pipe P1 and a conical tapered inner hole 12 following the inner hole 11 are formed inside the first joint member A1. An internal thread 13 is formed following the tapered inner hole 12. The taper angle of the taper inner hole 12 is set equal to the taper angle of the outer surface of the flare portion 10. The conical apex angle α (FIG. 4) formed by the outer surface of the flare portion 10 is 90 ° ± 3
It is set to 0 ', that is, about 90 °.

The second pipe P2 integrally has an elastic flange portion 14 at the end portion facing the first pipe P1. The flange portion 14 is integrally formed by processing the end portion of the second pipe P2, and has a portion 14a having a diameter increased to form a step, and subsequently a portion 14b having a conical surface diameter reduced.
It is composed of The rising angle of the step can be determined according to the shape of the tip portion 15 of the second joint member A2. The apex angle β (FIG. 4) of the conical surface-reduced portion 14b is 84
It is set to ± 2 °.

The second joint member A2 also has a cylindrical shape, has an inner hole 16 slidably fitted on the outer periphery of the second pipe P2, and has a screw 17 on the tip side of the outer peripheral surface. The external thread 17 is screwed with the internal thread 13 of the first joint member A1 as shown in the drawing when the pipe joint is assembled.

That is, since the apex angle β of the cone forming the flange portion 14 is 84 ± 2 °, which is smaller than about 90 ° of the apex angle α of the flare portion 10, the flange portion 14 and the flare portion 10 are not included.
As shown in FIG. 5, only the tip edge of the conical diameter-reduced portion 14b of the flange portion comes into contact with the inner surface of the flare portion 10 at the start of the contact between the flange portion 14 and the flare portion 10, as shown in FIG. , The facing surfaces of the two start contacting sequentially from the inner side to the outer side in the radial direction, and finally, the facing surfaces completely contact each other with elastic deformation.

In order to connect the pipe joints constructed as described above, as shown in FIG. 3, the first joint member A1 is fitted around the outer periphery of the first pipe P1, and similarly the second pipe P2 is connected. Second on the perimeter
The flare portion 1 of the first pipe with the joint member A2 of FIG.
0 and the elastic flange portion 14 of the second pipe are butted, and the female screw 13 and the male screw 17 of both joint members A1 and A2 are screwed together and tightened.

When the joint members A1 and A2 are tightened, the flare portion 10 and the flange portion 14 are pressed against each other between the tapered inner hole 12 of the first joint member A1 and the tip portion 15 of the second joint member A2. Due to its elasticity, the flange portion 14 conforms to the flare portion 10. That is, since the apex angle β of the cone forming the flange portion 14 is 84 ± 2 °, which is smaller than about 90 ° of the apex angle α of the flare portion 10, when the abutment of the flange portion 14 and the flare portion 10 is started, As shown in FIG. 5, only the tip edge of the conical reduced-diameter portion 14b of the flange portion comes into contact with the inner surface of the flare portion 10, and then, as the flange portion 14 and the flare portion 10 are pressed against each other, the opposing surfaces of both of them are radiused. The contact starts from the inner side to the outer side in order, and finally the two opposing surfaces come into full surface contact with elastic deformation. As a result, the conical surface-shaped inner surface of the flare portion 10 and the outer surface of the conical surface-shaped reduced diameter portion 14b of the flange portion 14 are in close contact with each other, and the reduced diameter portion 14b.
Continues to be pressed against it while exerting a reaction force due to its elastic deformation on the flare portion 10. Therefore, a strong sealing surface is formed between the two, and even if vibration or the like is applied by the action of the elastic force, the sealing surface is reliably held and leakage can be prevented even without packing.

As described above, in order to obtain intimate contact between the inner surface of the flare portion 10 and the outer surface of the flange portion 14, the angle α is about 90 °, that is, 90 ° ± 30 ', and the angle β is set as described above. It has been found that the most preferable setting is 84 ± 2 °. Tables 1 and 2 show performance comparisons between the conventional example in which α = 90 ° ± 30 ′ and β = 90 ± 2 ° and the present invention.

Table 1 Conventional pipe joint Result α 90 ° ± 30 'β 90 ± 2 ° Tightening torque without leakage Tightening torque 1.8kg ・ m Torque without leakage due to twist 2.0kg ・ m Regeneration without leakage Tightening torque 2.2kg ・ m Tightening torque without leakage even by axial tension 2.0kg ・ m Vibration 3G, 45Hz, 72 hours No abnormality Fatigue 10kgf / mm ² No abnormality Pressure resistance pulse pressure 350kg / cm ² No abnormality Table 2 Pipe fittings according to the present invention Result α 90 ° ± 30 'β 84 ± 2 ° Leak-free joint tightening torque 1.0 kg · m Torque without leakage due to twisting 1.0 kg · m Re-tightening without leakage Torque 1.0kg ・ m Tightening torque without leakage even when pulled in the axial direction 1.0kg ・ m Vibration 3G, 45Hz, 72 hours No abnormality Fatigue 10kgf / mm ² No abnormality Pressure resistance Pulse pressure 350kg / cm ² No abnormality Comparing Tables 1 and 2 above, in the present invention, there are tightening torque that does not cause leakage of the joint, torque that does not cause leakage even if twisted, re-tightening torque that does not cause leakage, and axial tension. Even if the tightening torque without leakage is much smaller than the conventional example, the apex angle β of the flange
It can be seen that reducing the value of is effective in preventing leakage of the joint. That is, in the present invention, leakage can be prevented with a small tightening torque.

[0018]

As described above, according to the present invention,
By setting the apex angle of the flange portion to 84 ± 2 °, members such as packing are not required other than the pair of joint members, the number of parts is minimal, and leakage does not occur due to vibration or the like.
A pipe joint that is easy to connect can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a collective pipe.

FIG. 2 is a sectional view of a conventional joint portion.

FIG. 3 is a vertical cross-sectional view showing a state after completion of connection of the pipe joint of the present invention.

FIG. 4 is a vertical cross-sectional view showing a state before connection between a first pipe P1 and a second pipe P2.

FIG. 5 is a partial cross-sectional view showing an initial contact state of the flare portion with the flange portion.

[Explanation of symbols]

 P1 1st pipe P2 2nd pipe A1 1st joint member A2 2nd joint member 10 Flare part 12 Conical-surface-shaped inner hole surface 13 Female screw 14 Elastic flange part 14a Step part 14b Conical-surface-shaped reduced diameter part 15 End 17 Male thread α Vertical angle of flare portion 10 β Vertical angle of flange portion 14

Claims (1)

[Claims] 1. A flare portion formed at an end portion of a first pipe to be connected, the flare portion being formed so as to have a diameter of a conical surface with increasing distance from the first pipe end, and an end portion of a second pipe to be connected. An elastic flange portion formed so as to expand in diameter to form a step and then reduce in diameter in a conical surface shape, and a conical surface shape fitted on the outer peripheral surface of the first pipe and extending along the outer peripheral surface of the flare portion. A first joint member having an inner hole surface and having an internal thread formed in an extension of the inner hole surface in the axial direction; and a first joint member fitted to the outer peripheral surface of the second pipe so as to come into contact with the step portion, A second joint member having an external thread on its outer peripheral surface that is screwed to the female thread, and the conical surface inner hole of the first joint member is formed by mutual tightening of the first and second joint members. Between the surface and the end surface of the second joint member that abuts the step portion, the flared portion and the elastic flange portion have a conical surface-like reduced diameter. And the apex angle of the conical surface of the flare portion and the apex angle of the conical surface-shaped inner bore surface of the first joint member are formed to be about 90 °, and the cone of the elastic flange portion is formed. A pipe joint characterized in that the apex angle of the planar reduced diameter portion is formed at 84 ± 2 °.