JPH09133274A - Pipe joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent fastening of a tube from loosening. SOLUTION: A pipe joint is provided with a joint main body 3 having inside a taper surface part 4 whose diameter is contracted toward a tube inserting port side and an inner circumferential part 5 which extends from the taper surface part 4 toward a tube inserting port side, and a collet 8 which is movably housed in the joint main body 3 in the axial direction of the joint main body 3 and which is guided to the taper surface part 4 during moving. When fluid pressure is acted in a condition in which a tube T is inserted in the collet 8, the collet 8 is moved toward the tube inserting port side along the taper surface part 4, and the collet 8 is contracted, and thereby, the tube T is fastened, and also the collet 8 is fastened by a corner part 15 formed between the taper surface part 4 and the inner circumferential part 5 finally. As a result, the tube T becomes in a slip-off condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint used for piping for air pressure or other fluids.

[0002]

2. Description of the Related Art Conventionally, pipe joints for use in piping for air pressure and other fluids have been known.

As shown in FIG. 6, this one has a joint main body 21 having a tapered surface 20 on its inner circumference, the diameter of which is reduced toward the tube insertion port side, and is movable in the joint main body 21 in its axial direction. It includes a collet 22 that is housed and is in engagement with the tapered surface 20 during movement. Then, when the fluid pressure acts in a state where the tube T is inserted into the collet 22, the collet 22 moves and is pressed by the tapered surface 20 of the joint main body 21 to reduce the diameter, so that the tube T is tightened and is prevented from coming off. Is a format that is connected to.

However, as shown in FIG. 7, when the collet 22 is engaged with the tapered surface 20, the axial force of the force F exerted on the collet 22 from the tapered surface 20 causes the collet 22 to move in the axial direction. Is easily displaced to the tube T
There was a problem that the tightening of might be easy to loosen.

[0005]

SUMMARY OF THE INVENTION Therefore, the present invention
It is intended to provide a pipe joint in which the tightening of the tube is less likely to be loosened than in the past.

[0006]

In order to solve the above-mentioned problems, the present invention employs the following technical means.

The pipe joint of the present invention has a tapered surface portion that reduces in diameter toward the tube insertion opening side and an inner peripheral surface portion that extends from the tapered surface portion that decreases in diameter toward the tube insertion opening side at its inner circumference. A main body and a collet that is movably housed in the joint main body in the axial direction thereof and is guided to the tapered surface portion during movement, and if a fluid pressure acts when the tube is inserted in the collet. , The collet moves toward the tube insertion port side along the tapered surface portion and contracts, whereby the tube is tightened, and finally the collet is formed by the corner portion between the tapered surface portion and the inner peripheral surface portion. It is characterized in that the tube is tightened so that the tube does not come off.

The pipe joint of the present invention is constructed as described above, and when the tube is in the retaining state, the force exerted on the collet by the corner portion is compared with the force exerted on the collet by the conventional tapered surface. , The direction of the force is closer to a right angle than the axial direction.

Therefore, the axial component of the force exerted on the collet by the corner portion is smaller than the axial component of the force exerted on the collet from the conventional tapered surface, so that the collet is displaced in the axial direction. It's hard to do.

Further, an inner peripheral locking portion is formed on the joint body, and an outer peripheral locking portion which should come into contact with the inner peripheral locking portion is formed on the collet, and the outer peripheral locking portion of the collet and the inner peripheral locking portion of the joint body are formed. It is also possible to bring the two into contact with each other so that they are locked in the axial direction.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 to 5, in the pipe joint of this embodiment, a joint main body 3 is constructed by caulking a second tubular member 2 to a first tubular member 1. The joint main body 3 is a tapered surface portion 4 whose diameter decreases toward the tube insertion port side.
And, it has an inner peripheral surface portion 5 extending from the tapered surface portion 4 having a reduced diameter toward the tube insertion port side on the inner periphery thereof. An O-ring 6 and a ring 7 are housed in the inner circumference of the first tubular member 1.

The joint main body 3 is provided with a collet 8 which is movably accommodated in the axial direction thereof and is guided by the tapered surface portion 4 during movement. As shown in FIG. 3, the collet 8 has a cylindrical shape and has an outer protruding portion 9 formed on the outer peripheral surface thereof and an engaging claw 10 formed on the inner peripheral surface thereof. An annular claw portion is formed so as to project toward the tube in the vicinity of the end portion on the inner side of the joint main body of the collet. The collet 8 is provided with a plurality of slits 11 that open to the insertion end side.
Reference numeral 12 is a push-in portion that is attached to the end portion of the collet 8 and that pushes the collet 8 when the tube T is released from the pipe joint.

Instead of the above-described collet, one of the slits may be a continuous collet from one end to the other edge, that is, a collet (not shown) having a circular cross section.

At the one end of the second tubular member 2 of the joint main body 3, an inward protruding piece that functions as an inner peripheral locking portion 13 which constitutes a retaining means for the collet 8 is formed. Further, an outer peripheral locking portion that comes into contact with the above-mentioned protruding piece in the middle of the peripheral wall of the collet 8.
Collet 8 is formed by engaging projections that function as 14
The outer peripheral locking portion 14 and the inner peripheral locking portion 13 of the joint main body 3 are brought into contact with each other so that both are locked in the axial direction.

When the fluid pressure acts while the tube T is inserted in the collet 8, the collet 8 moves toward the tube insertion port side along the tapered surface portion 4 and contracts, whereby the tube T is tightened. To go. Finally, the collet 8 has the tapered surface portion 4 and the inner peripheral surface portion 5.
The tube T is tightened from the corner portion 15 between and so that the tube T is prevented from coming off.

Next, the usage state of the pipe joint of this embodiment will be described. The tube T connected to this pipe joint is made of an elastic synthetic resin, and was used with the tubular shape-retaining metal fitting 16 inserted at the end when inserting and connecting.

In this pipe joint, when the tube T is in the retaining state, the force F exerted from the corner portion 15 to the collet 8 as shown in FIGS. 5 and 7 is the force F exerted from the conventional tapered surface to the collet. Compared with (see FIG. 7), the direction of the force F is closer to a right angle in the axial direction. Therefore, the axial component force Fx of the force F exerted on the collet 8 from the corner portion 15 is smaller than the axial component force Fx of the force F exerted on the collet from the conventional tapered surface, so that the collet 8 is It is difficult to displace in the axial direction.

Therefore, there is an advantage that the tightening of the tube T is less likely to be loosened than in the past.

[0020]

The present invention is configured as described above and has the following effects.

Since the collet is less likely to be displaced in the axial direction, it is possible to provide a pipe joint in which the tube tightening is less slack than in the conventional case.

[Brief description of the drawings]

FIG. 1 is a half sectional view of a pipe joint of this embodiment and a tube connected to the pipe joint.

FIG. 2 is a half sectional view showing a state where a tube is inserted into the pipe joint of FIG.

3 is a partially cutaway exploded perspective view of the pipe joint of FIG.

FIG. 4 is an enlarged half cross-sectional view showing the relationship between the joint main body and the tube collet when a fluid pressure is applied in a state where a tube is inserted in the pipe joint of FIG.

5 is an enlarged view of a main part of the pipe joint of FIG.

FIG. 6 is a half sectional view showing a state in which a tube is inserted into a conventional pipe joint.

FIG. 7 is a half cross-sectional view showing a relationship between a joint main body and a tube collet when a fluid pressure acts in a state where a tube is inserted into a conventional pipe joint.

[Explanation of symbols]

 3 Main body of joint 4 Tapered surface portion 5 Inner peripheral surface portion 8 Collet 13 Inner peripheral locking portion 14 Outer peripheral locking portion 15 Corner portion T tube

Claims (2)

[Claims] 1. A joint main body having, on its inner circumference, a taper surface portion that is reduced in diameter toward the tube insertion port side and an inner peripheral surface portion that extends from the taper surface portion that is reduced in diameter toward the tube insertion port side, and the joint. A collet that is movably accommodated in the axial direction of the main body and is guided to the tapered surface portion during movement, and when the fluid pressure acts in a state where the tube is inserted in the collet, the collet has the tapered surface portion. The tube is tightened by moving and contracting toward the tube insertion port side along with, and the collet is finally tightened by the corner portion between the tapered surface portion and the inner peripheral surface portion, and the tube is A pipe joint characterized by being in a retaining state. 2. An inner peripheral locking part is formed on the joint body, and an outer peripheral locking part to be brought into contact with the inner peripheral locking part is formed on the collet, and the outer peripheral locking part of the collet and the inner peripheral locking part of the joint main body. The pipe joint according to claim 1, wherein both parts are brought into contact with each other in the axial direction by bringing them into contact with each other.