JP2004308794A - Pipe fitting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide pipe fittings capable of effectively preventing projection of a seal ring without giving a bad influence to installation of a pipe body. <P>SOLUTION: In this fittings, when the seal ring 4 is fitted in a peripheral groove 5 of a fittings main body 10 and the pipe body 20 is inserted into the fittings main body, the pipe body 20 passes through the seal ring 4, and the fittings main body 10 and the pipe body 20 are sealed. A thick part 6 having a height lower than that of the seal ring 4 is provided in front and rear of the peripheral groove 5. Surface shape of the thick part 6 is desirably formed into an inclined surface formed higher on the peripheral groove side thereof or an arc surface. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a pipe joint capable of easily attaching and detaching a pipe body, and more particularly to a pipe joint capable of preventing a seal ring from protruding from a circumferential groove.
[0002]
[Prior art]
Pipe fittings that allow the pipe to be easily attached and detached are generally widely used. FIG. 2 is a reference view showing an overall image of such a pipe joint, in which a release ring 3 that can move back and forth and a lock ring 1 that can expand and contract in order from the pipe insertion port side of the joint body 10. Are located.
[0003]
In order to mount the pipe 20 in the pipe joint shown in FIG. 2, the pipe 20 may simply be inserted into the joint body 10. Then, the tube 20 passes through the inside of the release ring 3 as it is, and stops by contacting the V-shaped lock ring 1 whose cross section is horizontal, or the release ring 3 is moved to the back side by inserting the tube 20. Then, it comes into contact with the lock ring 1 and stops. When the tube body 20 is further inserted, the lock ring 1 has the V-shaped opening at the deeper side of the joint body 10, so that the outer surface of the tube body 20 pushes the inner periphery of the lock ring 1. And finally reaches the innermost part of the joint body 10 through the seal ring 4.
[0004]
When an internal pressure is applied in this state, the tube 20 receives a force in a direction away from the joint body 10, but the inner peripheral end of the lock ring 1 bites into the outer surface of the tube 20, thereby preventing the tube 20 from being detached. You. Further, the seal ring 4 is sandwiched between the joint main body 10 and the pipe body 20 and crushed, thereby preventing leakage of the internal fluid (for example, see Patent Document 1).
[0005]
[Patent Document 1]
JP-A-2002-5373 (page 2, FIG. 1-3)
[0006]
[Problems to be solved by the invention]
However, when the inner diameter of the tube 20 varies greatly, such as when the tube 20 is made of a resin, the outer diameter of the seal ring 4 is set so that it can contact at least the upper limit of the inner diameter of the tube 20. There must be. However, as shown in FIG. 3, if it is attempted to satisfy this condition by increasing the amount of protrusion of the seal ring 4 from the joint main body 10, the tubular body 20 having the lower limit of the inner diameter as shown in FIG. When inserted, there is a great risk that the seal ring 4 will be detached from the joint body 10 by the tube 20.
[0007]
If the tip of the tube 20 is cut obliquely, the tube 20 comes into contact with the seal ring 4 with a delay as shown in FIG. In a part (lower side), the pipe body 20 cannot smoothly pass over the seal ring 4, and the seal ring 4 is pushed as shown by an arrow and may protrude. Such protrusion of the seal ring 4 causes damage to the seal ring 4 and poor sealing.
[0008]
Further, the protrusion of the seal ring 4 causes insertion resistance of the tubular body 20, which may cause a misunderstanding that the tubular body 20 has reached the innermost part of the joint body 10. If the internal pressure acts in a state where the tube 20 is not sufficiently inserted, the tube 20 may come off or a sealing failure may occur.
[0009]
On the other hand, by increasing both the outer diameter of the joint body 10 and the outer diameter of the mounting of the seal ring 4 (from the dotted line to the solid line shown in the reference example of FIG. 4), the amount of protrusion of the seal ring 4 from the joint body 10 4B, the outer diameter of the joint body 10 may be larger than the inner diameter of the tube 20 at the lower limit of the inner diameter, as shown in FIG. 4B.
[0010]
At this time, when the pipe 20 is formed of a soft material made of resin, it is possible to insert the pipe 20 into the joint body 10 by pushing and expanding the pipe 20 with the joint body 10. The load required to insert the tube 20 into the joint body 10 increases.
[0011]
Therefore, an object of the present invention is to provide a pipe joint that can effectively prevent the seal ring from protruding without adversely affecting the fitting property of the pipe body.
[0012]
[Means for Solving the Problems]
The present invention has been made in order to solve the above problems, and the gist of the invention is that a seal ring is fitted into a peripheral groove of a joint body, and when a tube is inserted into the joint body, the tube body seals the seal ring. The present invention relates to a pipe joint in which a joint body and a pipe body are sealed by passing through the pipe joint, and a welded portion having a height lower than a seal ring is provided before and after a circumferential groove. Here, it is preferable that the surface shape of the built-up portion is an inclined surface or an arc surface with a high circumferential groove side.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
In the pipe joint of the present invention, a seal ring is fitted into a peripheral groove of the joint body, and when the pipe is inserted into the joint body, the pipe passes through the seal ring to seal the joint body and the pipe. . Here, the number of seal rings is not limited to one, and may be two or more. Further, the joint body may be a male type or a female type.
[0014]
As the mounting structure of the tubular body, a simple and generally used structure can be applied. For example, a release ring that can move back and forth and a lock ring that can expand and contract are arranged in order from the pipe insertion port side of the joint body, and when an internal pressure acts after the pipe is inserted, a lock ring is formed on the outer surface of the pipe. And the like to prevent the tube from coming off due to the inner peripheral end of the tube being cut into the inner periphery. To release the tube with this structure, the release ring may be pushed in, and the lock ring may be pushed open at its tip. Then, the engagement of the lock ring with the outer surface of the tube is released, and the tube can be easily pulled out.
[0015]
As described above, the pipe joint of the present invention is characterized by the provision of a built-up portion having a height lower than that of the seal ring before and after the circumferential groove, while maintaining the ease of installation. That is, in the pipe joint of the present invention, the build-up portion is provided only before and after the circumferential groove without raising the surface of the joint body as a whole. Therefore, as a result of the contact area with the tube being much smaller than the overall height, the insertion load of the tube does not change, and a general structure other than the overlay portion can be adopted.
[0016]
Here, the built-up portion provided in front of the circumferential groove, the gap between the joint body and the pipe body at the distal end side of the joint body to the conventional level, while maintaining the seal ring and the pipe body before the seal ring Of the seal ring to prevent the seal ring from protruding. For this reason, the overlay portion is preferably provided immediately before the circumferential groove, but may be provided at a position distant from the circumferential groove to some extent as long as the seal ring can be prevented from protruding.
[0017]
On the other hand, the built-up portion provided after the circumferential groove holds the seal ring pressed by the tubular body and prevents the seal ring from protruding. For this reason, it is preferable that the built-up portion be provided immediately after the circumferential groove, but may be provided at a position distant from the circumferential groove to some extent as long as the seal ring can be prevented from protruding.
[0018]
When there are two or more circumferential grooves, a built-up portion may be provided in front of the frontmost circumferential groove and after the last circumferential groove. Good. Further, the surface shape of the cladding portion is preferably an inclined surface or a circular arc surface with a high circumferential groove side from the viewpoint of the fitting property of the tube and prevention of the seal ring from protruding. It is preferable that the angle is not more than the value, the angle in the case of the inclined surface is 3 to 45 °, and the radius in the case of the arc surface is not more than four times the maximum height of the overlay.
[0019]
【Example】
Hereinafter, the best mode for a pipe joint according to the present invention will be described with reference to the drawings. FIG. 1 is a partial cross-sectional view showing an embodiment of the pipe joint of the present invention. In each of the embodiments of FIGS. 1 (A) to 1 (C), EPDM is used as a seal ring 4 in a circumferential groove 5 of a joint main body 10. O-ring is fitted. Further, before and after the circumferential groove 5, a built-up portion 6 having a height lower than that of the seal ring 4 is provided.
[0020]
In the embodiment shown in FIG. 1A, one seal ring 4 and one peripheral groove 5 are provided. The built-up portion 6B is provided, and its surface shape is a high inclined surface on the circumferential groove side. Here, the angle of the inclined surface is 8 °, and the maximum height is 0.1 mm.
[0021]
Further, in the embodiment shown in FIG. 1B, the surface shape of the overlay 6 is an arc surface, the radius of the arc is 0.1 mm, and the maximum height is 0 in FIG. 1A. .1 mm. Further, in the embodiment shown in FIG. 1 (C), two seal rings 4 and peripheral grooves 5 are provided as compared with FIG. 1 (A). However, no overlay portion is provided between the circumferential grooves 5.
[0022]
In each of such embodiments, the insertion of the tube 20 into the joint body 10 is performed very smoothly because the difference in diameter from the tube 20 at the distal end of the joint body 10 is the same as in the conventional example of FIG. . When the distal end of the tubular body 20 reaches the front overlay portion 6A, it easily gets over the inclined surface or the circular arc surface and reaches the seal ring 4.
[0023]
Then, since the difference in diameter between the seal ring 4 and the tube 20 is reduced, the insertion load does not change even if the tube 20 is continuously inserted. In addition, the seal ring 4 pressed by the tube body 20 is held by the built-up portion 6B, so that the seal ring 4 is prevented from protruding. Further, since the contact area with the pipe 20 is small only in the portion of the built-up portion 6, the load accompanying the subsequent insertion does not increase, and the pipe 20 easily passes through the seal ring 4, and the joint body 10 and the pipe 10 The body 20 is securely sealed.
[0024]
【The invention's effect】
The pipe joint of the present invention is a pipe joint in which a seal ring is fitted into a circumferential groove of a joint body, and when the pipe body is inserted into the joint body, the pipe body passes through the seal ring to seal the joint body and the pipe body. There is a built-up part at a height lower than the seal ring before and after the circumferential groove, so that the seal ring protrudes from the circumferential groove effectively while maintaining the ease of installation and detachment of the tube. And the cause of damage to the seal ring and poor sealing can be eliminated.
[Brief description of the drawings]
FIG. 1 is a partial sectional view showing an embodiment of a pipe joint of the present invention.
FIG. 2 is a reference diagram showing an example of an overall image of a pipe joint.
FIG. 3 is a partial sectional view showing a conventional example of a pipe joint.
FIG. 4 is a partial sectional view showing a reference example of the pipe joint.
[Explanation of symbols]
Description of Reference Numerals 1 ‥ Lock ring 3 ‥ Release ring 4 ‥ Seal ring 5 ‥ Circumferential groove 6 ‥ Overlay portion 6A ‥ Overlay portion 6B ‥ Overlay portion 10 ‥ Joint body 20 ‥ Tube

Claims (2)

When the seal ring (4) is fitted into the circumferential groove (5) of the joint body (10) and the tube (20) is inserted into the joint body (10), the tube (20) passes through the seal ring (4). A pipe joint in which the joint body (10) and the pipe (20) are sealed, and a padding part (6) having a height lower than that of the seal ring (4) is provided before and after the circumferential groove (5). A pipe joint characterized by being provided. 2. The pipe joint according to claim 1, wherein the surface shape of the cladding portion is a high inclined surface or a circular arc surface on the circumferential groove side. 3.

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