JPH0735875B2 - Pipe fitting - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a pipe joint used when joining pipe materials such as a hot water supply pipe and a water supply pipe.

(Prior Art) A pipe joint used when piping a hot water supply pipe, a water supply pipe, etc. using a synthetic resin pipe or a composite pipe in which the inner peripheral surface or both the inner peripheral surface and the outer peripheral surface of a metal pipe are covered with synthetic resin. However, the actual development 61-2299
It is disclosed in Japanese Patent No.

As shown in FIG. 7, the pipe joint has a joint body 60 on one side of which is provided a cylindrical connecting portion 63 which is connected to a device such as a valve or another pipe joint. On the other side of the joint body 60, a cylindrical guide portion 62 fitted in the end portion of the connecting pipe 50 is provided, and between the guide portion 62 and the connecting portion 63, an outer surface hexagonal shape is formed. A nut portion 64 is provided. A coupling portion 71 having a hexagonal inner surface of a tubular tightening member 70 is fitted and fixed to the nut portion 64. The outer surface of the connecting portion 71 is angular so that a tightening tool such as a spanner can be engaged with it. The fastening member 70 is provided with a fastening portion 72, which is externally fitted to the guide portion 62 of the joint body 60 at a predetermined interval, and is connected to the connecting portion 71. The outer diameter of the tightening portion 72 is smaller than the outer diameter of the connecting portion 71, and a thread groove is provided on the outer peripheral surface of the base end portion thereof. At the tip of the tightening portion 72, slits extending in the axial direction from the tip are formed at appropriate intervals in the circumferential direction, so that the tip can be reduced in diameter. Then, the cap nut 80 is screwed into the thread groove of the tightening portion 72, and by tightening the cap nut 80, the tip end portion of the tightening portion 72 is reduced in diameter.

In the pipe joint, the connecting portion 63 of the joint main body 60 is attached to a predetermined portion such as a valve, and the cap nut 80 is loosened, and the guide portion 62 of the joint main body 60 and the tightening portion 72 of the tightening member 70 are connected. The end of the connecting pipe 50 is inserted therebetween. Then, the cap nut 80 is rotated and tightened to reduce the diameter of the tip of the tightening portion 72 of the tightening member 70, and the connecting pipe 50 is attached to the outer peripheral surface of the guide portion 62 of the joint body 60 by the end of the tightening portion 72. The seal member 90 in the provided groove 62a is pressed. As a result, the end portion of the connecting pipe 50 is clamped by the guide portion 62 of the joint body 10 and the tightening portion 72 of the tightening member 70 to prevent it from coming off, and is connected to the guide portion 62 of the joint body 60 by the seal member 90. A liquid tight seal is provided between the pipe 50 and the pipe 50.

(Problems to be Solved by the Invention) In the conventional pipe joint having such a configuration, the joint body 60, the tightening member 70, and the cap nut 80 are usually manufactured from synthetic resin. When the fitting main body 60 is mounted on a device such as a valve, a tool such as a spanner is locked by the connecting portion 71 of the tightening member 70 and rotated, and a tightening torque is applied to the connecting portion 71 by the tool. At this time, when the tightening torque is large, only the connecting portion 71 of the tightening member 70 rotates with respect to the nut portion 64 of the joint main body 60, and the connecting portion 71 is cut at the corner of the inner surface to The connecting portion 71 may come off from the nut portion 64 of the joint body 60.

Further, the connecting pipe 50 is provided between the guide portion 62 of the joint body 60 and the tightening portion 72 of the tightening member 70 mounted on a predetermined device such as a valve.
Insert the end of the cap nut 80 and rotate the cap nut 80 to
If the cap nut 80 is excessively tightened when the tip portion is reduced in diameter, the tightening member 70 is drawn toward the cap nut 80.
As a result, the tip of the tightening portion 72 of the tightening member 70 is located at the joint body.
There is a possibility that the connecting pipe 50 may not be securely crimped to the seal member 90 due to a deviation from the facing position of the concave groove 62a provided on the outer peripheral surface of the guide portion 62 of the 60. If this happens, it may cause water leakage,
Further, the connecting pipe 50 may come off between the guide portion 62 and the tightening portion 72.

The present invention is to solve the above-mentioned conventional problems, and an object thereof is to prevent damage even when rotated by a tightening tool at the time of attachment to a predetermined device or joining with a connecting pipe, and the joined connection. (EN) It is intended to provide a pipe joint that reliably prevents the pipe from coming off and has excellent water leakage with the joint portion with the connecting pipe.

(Means for Solving the Problem) In the pipe joint of the present invention, the respective base ends are connected so that the inner cylinder and the outer cylinder are concentric with a gap into which the end of the connecting pipe is inserted. And a tube fixing member having a two-cylinder structure, in which the diameter-reducing tightening portion of the tip portion of the outer cylinder faces the seal portion on the outer peripheral surface of the inner cylinder and the tip portion of which is capable of reducing the diameter, and the tube fixing member. A joint main body having a cylindrical retaining portion on one side thereof, which retains the member inside with the tip of the outer cylinder extending outward and has a thread groove on the outer peripheral surface, and the retaining of the joint main body And a pressing member that is externally fitted and screwed to the portion to reduce the diameter of the outer cylinder tip portion of the pipe fixing portion in a state in which the end of the connecting pipe is inserted between the outer cylinder and the inner cylinder. As a result, the above purpose is achieved.

(Example) Hereinafter, the present invention will be described with reference to Examples.

As shown in FIG. 1 (a), the pipe joint of the present invention includes a tubular joint body 10 and a pipe fixing member disposed in the joint body 10.
It has 20 and a cap nut 30 which is a pressing member.

The joint body 10 includes a cylindrical connecting portion 13 arranged on one side in the axial direction and a cylindrical holding portion arranged on the other side in the axial direction.
It has 14 and the nut part 11 arrange | positioned between both.

A thread groove 13a is formed on the outer peripheral surface of the connecting portion 13, and the thread groove 13a is connected to a device such as a valve and other pipe joints.

The tubular nut portion 11 connected to the connecting portion 13 is
Has a flange shape projecting outward from the outer peripheral surface of the, and the outer peripheral surface is, for example, a hexagonal shape so that a tightening tool such as a spanner is engaged.

The holding portion 12 connected to the nut portion 11 has a cylindrical shape having an outer diameter sufficiently larger than the outer diameter of the connecting portion 13, and a thread groove 12a is formed on the outer peripheral surface thereof. . A cap nut 30 is screwed into the screw groove 12a. The inner diameter of the holding portion 12 excluding the base end portion thereof is slightly larger than the outer diameter of the connecting portion 13, and the inner diameter of the base end portion of the holding portion 12 is the same as the inner diameter of the nut portion 11. The inside of the base end of the holding portion 12 communicates with the inside of the nut portion 11. Then, the base end inner peripheral surface of the holding portion 12 and the inner peripheral surface excluding the inside of the base end portion are
It is connected at 12b to a connecting surface that communicates with the axis of the holding portion 12. An annular concave groove 12c opening toward the inside of the holding portion 12 is provided concentrically with the holding portion 12 in the connecting surface 12b, and an annular seal member 42 is fitted in the annular concave groove 12c. Has been done.

A pipe fixing member 20 is arranged in the holding portion 12 of the joint body 10. The pipe fixing member 20 has a two-cylinder structure having an inner cylinder 21 and an outer cylinder 22 that are concentric with each other, and both of them are holding members.
The base end portions located on the inner back side of 12 are connected to each other by a connecting portion 23 that is orthogonal to each axis.
The gap between the inner cylinder 21 and the outer cylinder 22 is slightly larger than the pipe thickness of the connecting pipe 50 so that the connecting pipe 50 to be connected can be inserted. The connecting portion 23 is the holding portion 12 of the joint body 10.
Can contact the connecting surface 12b.

The outer cylinder 22 of the pipe fixing member 20 has an axial length such that it extends outward from the tip of the holding portion 12 when the connecting portion 23 is in contact with the connecting surface 12b of the holding portion 12. Is set,
The tip of the inner cylinder 21 projects further outward than the tip of the outer cylinder 22.

As shown in FIG. 2, the outer cylinder 22 of the pipe fixing member 20 has a plurality of slits extending from its tip in the axial direction at its tip.
22a are provided at appropriate intervals in the circumferential direction, so that between the slits 22a, tongues 22b whose tip portions can be reduced in diameter are respectively formed. The tip of each tongue piece 22b has a reduced diameter tightening portion 22 protruding inward and outward in a semi-cylindrical shape.
c is provided for each. And this reduced diameter tightening part 2
A concave groove 21a is provided on the entire outer peripheral surface of the inner cylinder 21 facing the 2c, and an annular seal member 41 made of an elastic material such as rubber is fitted in the concave groove 21a.

A cap nut 30 is screwed into the guide portion 12 of the joint body 10. The cap nut 30 is in the shape of a rectangular tube having a cylindrical space inside. An opening into which the connecting pipe 50 can be inserted is formed at one end thereof, and a guide portion of the joint body 10 is formed at the other side.
It is open so that 12 can be inserted. On the inner peripheral surface of the cap nut 30 on the side where the guide portion 12 is fitted, a screw groove 31 that is screwed with a screw groove 12a provided on the outer peripheral surface of the guide portion 12 of the joint body 10.
Are formed. A taper surface 32a is formed on the inner peripheral side of the thread groove 31 on the inner peripheral surface of the cap nut 30 so that the inner diameter gradually decreases as the distance from the thread groove 31 increases. Right angle regulation end face 3
2b is formed. Tapered surface 32a and regulating end surface 32b
When the cap nut 30 is screwed into the holding portion 12, it comes into contact with the reduced diameter tightening portion 22c of the pipe fixing member 20.

The joint body 10, the pipe fixing member 20, and the cap nut 30 are usually formed of synthetic resin, but for example, only the pipe fixing member 20 may be formed of metal, or the whole may be formed of metal. is there.

The connection of the pipe joint having the above-described configuration to a device and the like, and the connection to the connection pipe 50 to the pipe joint are performed as follows.

When connecting the pipe joint of the present invention to a device such as a valve or another pipe joint, first, the connecting portion 13 of the joint body 10 is screwed into a threaded portion of the device or another pipe joint. At this time, first, a tightening tool such as a wrench is engaged with the outer peripheral surface of the nut portion 11 of the joint body 10 to perform screwing. However, since the nut portion 11 is formed integrally with the connecting portion 13, Sufficient tightening torque can be secured, and the joint body 10 is not likely to be damaged.

When connecting the connecting pipe 50 to a pipe joint connected to equipment or the like, a concave groove 12c provided on the connecting surface 12b of the holding portion 12 of the joint body 10 and a concave groove provided on the outer peripheral surface of the outer cylinder 22 are used. The pipe fixing member 20 is inserted into the holding portion 12 from the connecting portion 23 side with the sealing members 42 and 41 fitted in the groove 21a, respectively. Next, with the thread groove 31 of the cap nut 30 loosely screwed into the thread groove 12a on the outer peripheral surface of the guide portion 12, the cap nut 30
The connecting pipe 50 is inserted between the inner cylinder 21 and the outer cylinder 22 of the pipe fixing member 20 until the tip of the connecting pipe 50 contacts the connecting portion 23. When the tip of the connecting pipe 50 comes into contact with the connecting portion 23, the cap nut 30 is rotated, and the cap nut 30 is screw-fed toward the nut portion 11 of the joint body 10. By this screw feeding, first, the tapered surface 32a of the cap nut 30 contacts the reduced diameter tightening portion 22c at the tip of the outer cylinder 22. When the screw feed is further continued even after the tapered surface 32a comes into contact with the diameter reducing tightening portion 22c, the tongue pieces 22b at the tip of the outer cylinder 22 are successively reduced in diameter from the tip thereof. As a result, each of the reduced diameter tightening portions 22c presses the outer peripheral surface of the connecting pipe 50 toward the inner peripheral side, so that the connecting pipe 50 is recessed almost all around. The recessed portion of the connection pipe 50 fits into the concave groove 21a of the inner cylinder 21 and compresses the seal member 41 arranged in the concave groove 21a. As a result, the recessed portion of the connecting pipe 50 is sandwiched between the inner cylinder 21 and the reduced diameter tightening portion 22c at the tip of the outer cylinder 22,
The pipe fixing member 20 is prevented from coming off.

The tapered surface 32a of the cap nut 30 presses the reduced diameter tightening portion 22c when the reduced diameter tightening portion 22c abuts the tongue piece 2a.
The diameter of 2b is reduced, and the pipe fixing member 20 is pushed into the holding portion 12 of the joint body 10. When the pipe fixing member 20 is pushed into the holding portion 12, the connecting portion 23 of the pipe fixing member 20 is strongly brought into contact with the connecting surface 12b of the base end portion of the holding portion 12. As a result, the sealing member 42 provided in the concave groove 12c of the connecting surface 12b is compressed, the joint main body 10 and the pipe fixing member 20 are liquid-tightly sealed, and the pipe fixing member 20 is held by the holding portion. Fixed within 12. When the screwing of the cap nut 30 is further continued, the tip end of the diameter-reducing tightening portion 22c is pressed in the axial direction by the restricting end surface 32b of the cap nut 30, and the pipe fixing member 20 is pressed into the holding portion 12, and the pipe is fixed. The fixing member 20 is surely held in the holding portion 12 and the both are surely sealed.

In this way, the connecting pipe 50 has the reduced diameter tightening portion 22 of the inner cylinder 21 and the outer cylinder 22.
It is clamped by c and fixed to the pipe fixing member 20,
The pipe fixing member 20 is fixed to the joint body 10.
Therefore, the connecting pipe 50 is fixed to the holding portion 12 of the joint body 10. A seal member 41 seals between the inner peripheral surface of the connecting pipe 50 and the outer peripheral surface of the inner cylinder 21, and the joint body 10 and the pipe fixing member.
A seal member 42 seals the gap between the gap 20 and the gap 20. Therefore, the space between the inner peripheral surface of the connecting pipe 50 and the joint body 10 is sealed.

The cap nut 30 is screwed in by engaging a tightening tool such as a spanner with its outer peripheral surface. The holding portion 12 formed integrally with the joint body 10 is not likely to be deformed even if an excessive tightening torque is applied to the holding portion 12 by the cap nut 30. Even if the holding portion 12 is deformed, the outer cylinder 22
There is no force to displace the to the tip side. As a result, the connecting pipe
The 50 is reliably pressed against the seal member 41, and there is no risk of impairing the sealing performance. Therefore, even if the cap nut 30 is excessively tightened, the connecting pipe 50 is not detached and the seal is not defective.

FIG. 3 is a sectional view showing another embodiment of the pipe joint of the present invention. In this embodiment, a concave groove 12b is formed on the inner peripheral surface of the holding portion 12 of the joint body 10, and a groove for sealing between the joint body 10 and the pipe fixing member 20 is formed in the concave groove 12b. The seal member 41 is fitted. The outer peripheral edge portion of the end portion of the outer cylinder 22 on the side of the connecting portion 23 is chamfered, so that when the pipe fixing member 20 is inserted into the holding portion 12, the seal member 41 is not likely to be damaged.

FIG. 4 is a sectional view showing still another embodiment of the pipe joint of the present invention. In this embodiment, the inner cylinder 21 of the pipe fixing member 20 is further extended to the base end side than the connecting portion 23, and the extended portion 21b is
Base end portion of the holding portion 12 and the nut portion of the joint body 10
It is inserted in an annular recess 15 formed in 11. A seal member 42 that seals between the joint body 10 and the pipe fixing member 20.
Is fitted in a groove 15a formed on the inner peripheral surface of the annular recess 15. In addition, the outer peripheral edge portion of the extended portion 21b has a seal member 42
Chamfered to prevent damage to the.

FIG. 5 is a sectional view of the essential part showing another embodiment of the pipe joint of the present invention. In this pipe joint, tapered tongues 22d are provided on the outer peripheral surface of each tongue piece 22b provided at the tip of the outer cylinder 22 of the pipe fixing member 20. This tapered claw 22d
Has a diameter that gradually increases toward the tip side, and its end face has a triangular cross-section that is orthogonal to the axis. Holding part 12
The inner peripheral surface has an annular groove 1 having a shape corresponding to the tapered claw 22d.
2d is provided, and when the pipe fixing member 20 is inserted into the holding portion 12, each tapered claw 22d fits into the annular groove 12d. As a result, the pipe fixing member 20 is held in the holding portion 12 with the pipe fixing member 20 inserted to a predetermined position. As a result, the pipe fixing member 20 is prevented from coming off the joint body 10.

FIGS. 6 (a) and 6 (b) are sectional views showing another embodiment of the reduced diameter tightening portion 22c. Diameter reduction tightening portion 22c of FIG. 6 (a)
The inner peripheral side surface bulges in an arc shape and the outer peripheral surface surface protrudes outward in a triangular shape in cross section. The reduced diameter tightening portion 22c of FIG. 6 (b) has a triangular cross section in which the inner peripheral side surface also protrudes inward, and is formed in a wedge shape as a whole. In either case, the taper surface 32a of the cap nut 30 exerts a reducing force and a pushing force in the axial direction on the pipe fixing member 20.

In addition, although the above-mentioned embodiment explained the straight pipe type pipe joint, the present invention is also applicable to, for example, an elbow type pipe joint.

(Effect of the invention) In the pipe joint of the present invention, since the pipe fixing member that is separate from the joint body is held in the holding portion of the joint body in this way,
When the joint body is connected to a device or the like, no force is directly applied to the pipe fixing member, and even if an excessive tightening torque is applied to the joint body, the joint body is not likely to be damaged. Further, even if an excessive tightening torque is applied to the pressing member, the connecting pipe is surely brought into contact with the sealing member, so that the water tightness with the connecting pipe is not impaired, and the connecting pipe is securely connected. Is locked in.

[Brief description of drawings]

FIG. 1 (a) is a sectional view showing an example of the pipe joint of the present invention,
FIG. 1 (b) is a sectional view for explaining the operation, FIG. 2 is a side view of a pipe fixing member in the pipe joint of FIG. 1, and FIGS.
FIG. 5 is a cross-sectional view of an essential part showing another embodiment of the pipe joint of the present invention, FIG. 6 is a cross-sectional view of an essential part of another embodiment of the pipe fixing member, and FIG. 7 is a cross-section of a conventional pipe joint. It is a figure. 10 …… Coupling body, 11 …… Nut part, 12 …… Holding part, 13 ……
Connection part, 20 …… pipe fixing member, 21 …… inner cylinder, 22 …… outer cylinder, 22c
...... Reduced diameter tightening part, 23 …… Coupling part, 30 …… Cap nut, 41,42…
… Seal member, 50 …… Connection pipe.

Claims (1)

[Claims] 1. A two-cylinder structure in which base ends are connected so that an inner cylinder and an outer cylinder are concentric with each other with a gap into which an end of a connecting pipe is inserted. A tube fixing member having a reduced diameter tightening portion at the tip end of the inner cylinder facing the seal portion on the outer peripheral surface of the inner cylinder, and the tip end portion of which can be reduced in diameter; A joint body having a cylindrical holding portion on one side, which is held inside in an extended state and has a thread groove formed on an outer peripheral surface, and a pipe which is externally fitted and screwed to the holding portion of the joint body. A pipe joint comprising: a pressing member that reduces a diameter of a tip portion of the outer cylinder of the fixed portion in a state where an end portion of the connecting pipe is inserted between the outer cylinder and the inner cylinder.