JP4740709B2 - Pipe joint structure - Google Patents

Description

  The present invention relates to a pipe joint structure, and more particularly to a joint structure for a resin pipe used for a water supply / hot water pipe.

  In recent years, resin pipes such as polybutene and cross-linked polyethylene have been used for water supply and hot water supply pipes, and joints for connecting these pipes have been developed. The joint has a structure in which a sealing material and a metal pipe holding material are built in the joint, or the pipe holding material is composed of a composite of a metal claw portion and a resin ring. It is.

  However, the metal claw has a holding function for the pipe, but in this case, depending on the shape of the pipe holding material, it does not hold the pipe under high temperature and high pressure, and the connected pipe is There was a possibility of getting out. In the case of a composite part of metal and resin, the resin to be used is required to have equivalent chemical resistance and durability, and an expensive resin must be used as the resin.

  That is, when holding a pipe using a pipe holding material provided with a metal claw projecting toward the outer surface of the pipe, the holding power of the pipe increases depending on the extent that the claw bites into the surface of the pipe. In some cases, however, the claw will sometimes cause the pipe surface to be scratched long in the axial direction of the pipe, and if the O-ring straddles this scratch, the fluid flowing in the pipe will Result in leakage through.

  The present invention has been made in view of the need to improve the drawbacks of these prior arts, and uses a holding function member formed of a resin in combination with making the most of the characteristics of a metal pipe holding material. This is an improvement of the conventional defect.

  The gist of the present invention is a sealing material that exerts a sealing function by being pressed against an outer surface of a pipe inserted into a joint base, and a pipe holding material that exerts a retaining function by biting into the outer surface of the pipe. And a pipe joint that prevents the pipe from being pulled out by a cap screwed to the joint base, wherein the pipe holding material has a metal claw portion protruding toward the outer surface of the pipe. The structure is characterized in that the body A and the resin-made annular holding body B that can be reduced in diameter toward the outer surface of the pipe are used in combination.

  The pipe joint structure of the present invention is a joint that has both the holding force of the pipe due to the biting of the claw portion of the holding body A and the pipe movement preventing force mainly due to the reduced diameter of the holding pair B. Was extremely superior to the conventional one.

  In addition to the pipe holding function of the metal holding body A, the present invention adds a holding function part formed only of a general-purpose resin, that is, the holding body B into the joint, so that the holding function can be sufficiently maintained even under conditions of high temperature and high pressure. At the same time, it is possible to form a house structure for the O-ring and to improve the pipe insertion performance.

  Among the pipe holding members, the metal holding body A provided with the claw portion is provided with a plurality of claw portions a arranged so as to be inclined toward the inner diameter side from the short annular ring, and the claw portion a The inclination of is the same as the pipe insertion direction.

  When the pipe is inserted, the claw portion a has little resistance to the pipe, but when the pipe is about to come out, the claw portion a functions to bite into and hold the outer surface of the pipe. As another example of the metal holding body A of the present invention, the metal holding body A may not necessarily be a single metal body, and in some cases, a claw portion a may be embedded in an annular resin body. The outer surface of the holding body A is formed with an inclined surface corresponding to the inclination of the claw portion a, and the cap is also provided with an inclined surface facing the inclined surface. A structure that restricts the movement (missing) of the holding body A is preferable.

  On the other hand, the diameter-reducing resin-made annular holder B is used as a short tube with a crystalline resin such as polyacetal, polyphenylene sulfide, and polyetherketone. b may be provided. A plurality of slits are formed from one end to a depth not less than the claw b. The claw b is initially in contact with the outer surface of the pipe with a not so strong force. However, when the pipe is about to come out, the claw b bites into the pipe, and further, the diameter of the claw b is reduced to the inside to reduce the outer surface of the pipe. Presses strongly and demonstrates the function of preventing the pipe from coming off.

  As described above, the present invention has a configuration in which the pipe is prevented from being pulled out by the claw portions a and b that bite into the outer surface of the pipe as much as the pipe is about to escape and the strong pressure due to the reduced diameter of the holding body B. is there.

  Hereinafter, the present invention will be described in more detail with reference to the drawings. 1 is a front view of the metal holder A, FIG. 2 is a rear view, and FIG. 3 is an end view taken along the line AA. That is, the back surface is composed of a short tubular ring portion 2 having an inclined surface 1 and eight claw portions a formed on the small diameter side of the ring portion 2. The inner peripheral side of the ring portion 2 is also an inclined surface 3 parallel to the inclined surface 1 on the back surface. The claw portion a is provided to be inclined in the X1 direction in the figure, where X1 represents the insertion direction of the pipe P and X2 represents the removal direction of the pipe P. The inner diameter of the eight claw portions a is equal to or slightly larger than the outer diameter of the pipe P to be inserted.

  4 is a front view of the resin holder B, FIG. 5 is a rear view, and FIG. 6 is a sectional view taken along the line BB. This holding body B is entirely made of polyacetal resin, and six slits 11 are cut from the back side. Preferably, a small protrusion (claw part) b is formed on the inner side of the center of the holding body B. It is formed inward. The inner diameter of the claw b is approximately the same as or slightly larger than the outer diameter of the pipe P. Note that the outer surface on the back side is slightly tall and forms an inclined surface 12. And preferably, the inner surface also forms the inclined surface 13 and is shaped so as to be substantially fitted to the ring portion 2 and the claw portion a of the metal holding body A.

  FIG. 7 is an enlarged half-cut view showing the positional relationship between the metal holder A and the resin holder B. FIG. FIG. 8 shows a pipe joint T according to the present invention, and is a half-cut view when these holding bodies A and B are built in a joint base T0. That is, an O-ring C, a holding body B, and a holding body A, which are in contact with the outer surface P0 of the pipe P and are sealed in the joint base T0, are inserted in this order, and these are provided with a cap D that is screwed with the joint base T0. It has a structure that prevents slipping out.

  When the pipe P is inserted from the cap D (X1 direction), the end of the pipe P abuts against the stepped portion 21 formed on the innermost side of the joint base T0, and the insertion is completed. In this case, the O-ring C Is brought into contact with the outer surface P0 of the pipe P to complete the sealing function. The claw portions a and b do not so much bite into the outer surface P0 when the pipe P is inserted.

  However, when a fluid flows in the joint T and the pipe P, a force is applied in a direction (X2 direction) to the pipe P due to the fluid pressure. Here, the claw portions a and b exert a function of biting into the outer surface P0 of the pipe P and preventing the pipe P from coming off. Furthermore, the relationship between the pipe P and the metal holding body A is that the claw part a bites into the surface P0 as the pipe P moves in the X2 direction, and the inclined surface 1 on the back surface of the holding body A is a cap. The movement of the holding body A itself is sealed by contact with the inclined surface 22 formed at the tip of D, and the claw portion a firmly bites into the outer surface P0 of the pipe P.

  On the other hand, in the claw portion b, the holding body B also tries to move in the X2 direction by moving in the direction in which the pipe P is pulled out (X2 direction). Will fit inside the ring part 2 and the claw part a of the holding body A, and will be unable to move. However, since the holding body B is formed with the slits 11, this extra force can be reduced in diameter by the width of the slits 11. This provides a double blocking function in which the outer surface P0 of the pipe P is strongly pressed to prevent the pipe P from coming off.

  Since the pipe P is strongly pressed toward the inner diameter side, for example, a metal collar is generally fitted into the tip of the pipe P to be inserted and used.

  The present invention is as described above, and prevents the pipe from coming out of the joint. The pipe can be applied not only to resin but also to metal, and the type of fluid is also particularly limited. However, it can be used for a wide range of joints.

FIG. 1 is a front view of a metal holder A. FIG. FIG. 2 is a rear view of FIG. FIG. 3 is an end view taken along line AA. FIG. 4 is a front view of the resin holder B. FIG. FIG. 5 is a rear view of FIG. FIG. 6 is a sectional view taken along line BB. FIG. 7 is a half-cut view showing the positional relationship between the metal holder A and the resin holder B. FIG. FIG. 8 shows a pipe joint of the present invention.

Explanation of symbols

11. Slit,
a. Claw part of holder A,
b. Claw part of holder B,
A ... Metal holding body,
B: Resin holder
C. Sealing material (O-ring),
D. Cap,
P ... pipe,
P0 ... the outer surface of the pipe,
T: Fitting,
T0: Joint base,
X1 Pipe insertion direction,
X2 Pipe exit direction.

Claims (3)

In the joint base, incorporates the sheet over the ring member is pressed against the outer surface of the pipe to be inserted by exerting a sheet Lumpur function and pipe holding member to exert a holding function bite into the outer surface of the pipe, fitting base A pipe joint structure that prevents the pipe from being pulled out by a cap screwed into the pipe,
Before Symbol pipe holding material,
A holding body A having a metal annular portion with one diameter expanded, and a metal claw portion a projecting toward the outer surface of the pipe connected to the other of the metal annular portions ;
A resin annular holder B capable of reducing the diameter toward the outer surface of the pipe ;
With
An outer surface and an inner surface of the resin annular holder B form an inclined part, and the inclined part is fitted between the metal annular part of the holder A and the metal claw part a. Has become,
Pipe joint structure according to claim and this. The pipe joint structure according to claim 1, wherein a slit is formed in the resin annular holder B in an axial direction. The pipe joint structure according to claim 1 or 2, wherein the resin annular holding body B includes a claw portion b protruding toward an outer surface of the pipe.

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