JP2001065763A - Joint for resin pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable easy and speedy connection work even at a narrow site by providing a joint body having an inserting inner cylindrical part formed with a spiral projection portion at its outer circumferential surface and inserted into a resin pipe, and a resin pipe fastener fitted around the joint body so as to fasten the resin pipe. SOLUTION: This resin pipe joint which can easily removing a resin pipe 1 as well as which ensures firm prevention of slipping-out of the pipe 1 for holding a stable connection condition is provided with a joint body 2 and a resin pipe fastener 30 that has an outer cylindrical member 3 and a coil spring 4. The joint body 2 has an inner cylindrical part 5 to be inserted into the pipe 1, the part 5 having a spiral protrusion 8 at its outer periphery 7 where a plurality of recess-like circumferential grooves 9 are formed. An annular packing 10 is inserted into the groove 9, and with the annular packing body 10 and the spiral protrusion 8, slipping-out of the pipe 1 and leakage of fluid to the outside are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a joint for a resin pipe.

[0002]

2. Description of the Related Art Heretofore, there has been widely used a method in which a tapered male screw portion is cut at the end of a resin pipe to be connected, and a female screw portion of a joint is screwed to this.

[0003]

However, in this joint, if the work site is small and the joint main body is large or L-shaped, the joint main body is rotated and screwed into the resin pipe. May not be able to be performed, causing a problem. Further, when the thickness of the resin pipe is small, it is difficult or impossible to machine the external thread. Further, when screwing and connecting, the resin pipe may be subjected to a force and may be deformed or damaged. Also, it was difficult to remove the resin pipe.

Therefore, the present invention can easily and quickly perform a connection operation even in a small site, can firmly prevent the resin pipe from being pulled out, can maintain a stable connection state without rattling, and can maintain the connection state of the resin pipe. An object of the present invention is to provide a resin pipe joint that can be easily removed.

[0005]

In order to achieve the above-mentioned object, a joint for a resin pipe according to the present invention comprises a plug-in inner cylindrical portion having a spiral ridge on an outer peripheral surface inserted into the resin pipe. And a resin pipe tightening mechanism which is externally fitted to the joint main body so as to surround the insertion inner cylindrical portion and tightens the resin pipe.

Also, a joint body having an insertion inner cylinder portion provided with a spiral ridge on an outer peripheral surface inserted into the resin pipe; a spiral groove on the inner peripheral surface and surrounding the insertion inner cylinder portion. An outer cylindrical body externally fitted to the joint body so that the inner end is fixed to the inner end side of the outer cylindrical body, and an intermediate portion is screwed into the spiral groove; Part is detachably locked to the outer end side of the outer cylindrical body, and the inner diameter is expanded against the elastic force so that the inner diameter is larger than the outer diameter of the resin pipe. A coil spring having an inner diameter smaller than the outer diameter of the pipe.

Also, a joint body having a plug-in inner cylinder portion provided with a spiral ridge on the outer peripheral surface inserted into the resin pipe; a spiral groove on the inner peripheral surface and surrounding the plug-in inner cylinder portion An outer cylinder body fitted to the joint main body so as to be fitted; a small cylinder body rotatably connected to an outer end side of the outer cylinder body around an axis;
The inner end is fastened to the inner end of the outer cylinder, and the intermediate portion is screwed into the spiral groove, and the outer end is fastened to the outer end of the small cylinder. The small cylindrical body is locked to the outer cylindrical body so as to be switchable for rotation locking, and the inner diameter is expanded against the elastic force so that the inner diameter is larger than the outer diameter of the resin pipe. A coil spring having an inner diameter smaller than the outer diameter of the resin pipe in a free state.

A joint main body having a plug-in inner cylindrical portion provided with a spiral ridge on the outer peripheral surface inserted into the resin pipe; a spiral groove on the inner peripheral surface and surrounding the plug-in inner cylindrical portion; An outer cylinder body rotatably fitted around the axis of the joint body so that the inner end is fixed to the joint body; and
An intermediate portion is screwed into the spiral groove, and an outer end portion is fixed to an outer end side of the outer cylindrical body, and the outer cylindrical body is rotatably locked to the joint main body. And a coil spring having an inner diameter that is larger than the outer diameter of the resin pipe and is expanded against the elastic force so as to have an inner diameter smaller than the outer diameter of the resin pipe in a free state. It is composed.

Further, the spiral groove on the inner peripheral surface of the outer cylinder has a shape having a tapered surface portion whose diameter is reduced outward.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing embodiments.

FIGS. 1 and 2 show an embodiment of a joint for a resin pipe according to the present invention. This joint comprises a resin pipe 1 made of cross-linked polyethylene, polyethylene or other resin.
The joint body 2 and the resin pipe tightening mechanism 30 are provided. The resin pipe tightening mechanism 30 includes the outer cylinder 3 and the coil spring 4. In addition, the resin pipe 1
Is defined as the outer end side.

The joint body 2 has, on one side, a plug-in inner cylinder part 5 inserted into the resin pipe 1, on the other side a socket type having a male screw, and on the other side, a similar type. It may be a straight type or an elbow type having a structure, or a T-type as a whole, each of which is a cheese type having the same structure as described later, and is generally made of metal. More specifically, the insertion inner cylindrical portion 5 is provided with a spiral ridge 8 on the outer peripheral surface 7 thereof, and further has a plurality of circumferential concave grooves 9 in the outer peripheral surface 7 in the axial direction. I have. And in the concave circumferential groove 9,
The annular packing body 10 is inserted, and the packing body 10 and the spiral ridge 8 prevent the resin pipe 1 inserted into the insertion inner cylinder part 5 from being pulled out and prevent the fluid from leaking to the outside. You.

The outer cylinder 3 has a helical groove 6 on the inner peripheral surface, and is externally fitted to the joint body 2 so as to surround the insertion inner cylinder 5. More specifically, a mounting groove 11 is provided on the outer peripheral surface of the intermediate portion of the joint body 2, and the inner end side of the outer cylinder 3 is formed from outside by a plastic deformation such as a punch.
Are fitted into the mounting grooves 11, and are attached so that the outer cylinder 3 does not come off from the joint body 2. Note that the outer cylinder 3 may be attached to the joint body 2 so as not to rotate, with the attachment groove 11 serving as a small recess.

The coil spring 4 has an inner end 4
a is fixed to the inner end side of the outer cylinder 3, and the intermediate portion is screwed into the spiral groove 6, and the outer end 4 b is detachably locked to the outer end of the outer cylinder 3. Thus, the resin pipe 1 is in a standby state for connection of the resin pipe whose diameter has been expanded against the elastic force so that the inner diameter Ds is larger than the outer diameter Dp of the resin pipe 1.

More specifically, a through hole 13 is provided on the inner end side of the outer cylinder 3, and the inner end 4 a of the coil spring 4 is provided.
Are inserted into the through-hole 13 in an inserted manner. A locking projection 14 is provided on the outer edge of the outer cylinder 3 so as to protrude outward in the axial direction, so that the outer end 4b of the coil spring 4 can be detached from the locking projection 14. It is locked. Further, an intermediate portion between the inner end portion 4a and the outer end portion 4b is loosely screwed into the spiral groove 6 of the outer cylindrical body 3. In addition, it is also preferable to provide a through hole on the outer end side of the outer cylinder body 3 and lock the outer end portion 4b in the through hole so that the outer end portion 4b can be detached.

Then, the coil spring 4 is arranged as shown in FIG.
As shown in (a), in the free state, the resin pipe 1 has an inner diameter Ds smaller than the outer diameter Dp.
As shown in the figure, the inner diameter Ds is attached to the outer cylinder 3 as described above in a state where the inner diameter Ds is expanded against the elastic force so as to be larger than the outer diameter Dp of the resin pipe 1. In addition, FIG.
The height H from the inner end portion 4a to the outer end portion 4b of the coil spring 4 whose diameter is expanded as described above is larger than the height H in the free state shown in FIG.

As described above, the coil spring 4 in the connection standby state of the resin pipe 1 to the main joint is resiliently urged, and as shown in FIG. 1 and FIG. 4b, the height H is the tensile force Fx to be reduced.
The outer end 4b is locked to the locking projection 14 while the inner diameter Ds and the tensile force Fy for reducing the inner diameter Ds are applied.

After that, the resin pipe 1 is inserted into the main joint to connect the resin pipe 1. 2 and 4
As shown in FIG. 7, a recess 15 is formed near the outer end 4b and at the outer edge near the root of the locking projection 14 of the outer cylindrical body 3. As shown in FIG. Then, as shown in FIG. 4A, a jig 16 (such as a pin or a screwdriver) is inserted into the recessed portion 15 to resist the tensile force Fx of the outer end 4b (the height H is about to be reduced). Then, a force is applied to the outer end portion 4b by the jig 16 and
As shown in (b), when a force is applied so that the outer end 4b passes over the locking projection 14, the outer end 4b is pulled by the tensile force Fy (the inner diameter Ds is about to decrease). Over part 14,
As shown in FIG. 4C, the outer end 4 b is in a state of being separated from the locking projection 14.

Then, as shown in FIG.
Is connected to this joint. More specifically, in the resin pipe connection standby state shown in FIG.
Is removed as described above, the coil spring 4 tightens the resin pipe 1 as shown in FIG. Inner diameter D of coil spring 4 in this resin pipe tightened state
s is larger than the inner diameter Ds in the free state (FIG. 3A), and the height H of the coil spring 4 in the resin pipe tightened state is the height H in the free state (FIG. 3A). Therefore, the coil spring 4 is tightening the resin pipe 1 in a state of being elastically urged. Further, the coil spring 4 may bite into the resin pipe 1 due to the elastic bias, and the inner diameter Ds of the coil spring 4 in the tightened state may become smaller than the outer diameter Dp of the resin pipe 1. Therefore, the retaining of the resin pipe 1 is further strengthened.

As described above, the resin pipe 1 in the connected state
Is firmly attached to the joint by the tightening force of the coil spring 4, the packing bodies 10, and the spiral ridges 8 biting into the resin pipe 1 as shown in FIG.
The retaining of the resin pipe 1 is strengthened, and the leakage of the fluid to the outside is prevented.

The spiral groove 6 on the inner peripheral surface of the outer cylinder 3 is
FIG. 6 shows a shape having a tapered surface portion 17 contracting outward.
As shown in (a), when a pulling force is applied to the resin pipe 1, the coil spring 4 tightening the resin pipe 1 moves together with the resin pipe 1 in the drawing direction (axial direction), and FIG. As shown in b), the coil spring 4
Is pressed against the tapered surface portion 17 of the spiral groove 6. And (as shown in FIG. 5), the outer cylinder 3 is
Because it is mounted so that it does not move in the axial direction,
The tapered surface portion 17 presses the coil spring 4 and increases the tightening force of the coil spring 4 on the resin pipe 1.
Accordingly, when the pulling force of the resin pipe 1 increases due to such a wedge state, the tightening force further increases.

When the connected resin pipe 1 is pulled out from the present joint, as shown in FIG.
Can be pulled out by rotating the resin pipe 1 (or the joint main body 2) around the axis. That is, the screw engagement between the resin pipe 1 and the spiral ridge portion 8 caused by the biting by the tightening of the coil spring 4 can be mutually removed by the screw retreating action. In addition, the spiral bite trace 28 of the resin pipe 1 (generated by the biting of the spiral ridge 8) can be screwed into the spiral ridge 8 again.

Therefore, when re-starting due to failure of repair or connection work, the resin pipe 1 and the joint body 2 can be relatively rotated and removed (separated) without cutting the resin pipe 1, and further, the resin pipe 1 can be removed again. The connection of the pipe 1 becomes possible. Moreover, there is no inconvenience that the length of the resin pipe 1 becomes shorter each time the process is repeated.

FIG. 8 shows another embodiment of the present joint. This joint includes a joint main body 2, an outer cylindrical body 3, a coil spring 4, and a small cylindrical body 18. A plurality of mounting grooves 19 are provided on the outer peripheral surface of the intermediate portion of the joint body 2,
A through insertion hole 20 is provided on the inner end side of the outer cylindrical body 3, and the locking tool 21 (such as a screw or a pin) is pressed (screwed or press-fitted) from the outside to form the through insertion hole 20 and the mounting groove. 19, the outer cylinder 3 is fixedly attached to the joint body 2.
The mounting groove 19 is used as a circumferential groove, and the outer cylinder 3 is connected to the joint body 2.
May be mounted so as to rotate relative to each other.

The coil spring 4 has an inner end 4
a is fixed to the inner end side of the outer cylinder 3, the intermediate portion is screwed into the spiral groove 6, and the outer end 4 b is fixed to the outer end of the small cylinder 18. The small cylinder 18 is rotatably connected to the outer end of the outer cylinder 3 so as to be rotatable around the axis.
18 is locked to the outer cylindrical body 3 so as to be detachable (rotation locking switchable) in the rotation direction (as shown in FIG. 3B).
The inner diameter Ds of the coil spring 4 is equal to the outer diameter D of the resin pipe 1.
A resin pipe connection standby state in which the diameter has been expanded against the elastic force so as to be larger than p is set.

More specifically, the small cylinder 18 is rotatably mounted around the axis so as to surround the outer end of the outer cylinder 3. The inner end 4a of the coil spring 4 is fixed to the outer cylinder 3, the outer end 4b is fixed to the small cylinder 18, and the coil spring 4 expands in diameter against the elastic force. Therefore, the small cylindrical body 18 is moved by the tensile force Fy (the inner diameter Ds is about to be reduced) of the outer end 4b.
To rotate around the axis. However, a plurality of engaging protrusions 22 provided on the inner end edge of the small cylindrical body 18 are provided on the outer peripheral surface of the outer cylindrical body 3 (to face the engaging protrusions 22 ...). (Or engaging recesses), the small cylindrical body 18 maintains the state where the rotational force about the axis is urged, and FIG.
(As shown in (b)), a resin pipe connection standby state is set.

After that, the resin pipe 1 is inserted into the main joint to connect the resin pipe 1. That is, the engaging projections 22 of the small cylindrical body 18 are separated from the engaging projections 23 of the outer cylindrical body 3 against the tensile force Fx (the height H is about to decrease) of the outer end 4b. When disengaged, the small cylinder 18 rotates around the axis (along with the outer end 4b), and the coil spring 4 is brought into the resin pipe tightening (connection) state (as shown in FIG. 3C). The small cylindrical body 18 does not come out of the outer cylindrical body 3 in the axial direction due to the tensile force Fx of the outer end 4b, and is made firm.

When the connected resin pipe 1 is pulled out from the joint, the resin pipe 1 is pulled out against the resilient force of the coil spring 4.
By rotating the small cylinder 18 around the axis (relative to the outer cylinder 3),
By engaging the engaging projections 22 of the small cylindrical body 18 with the engaging projections 23 of the outer cylindrical body 3, the resin pipe 1 can be pulled out with the coil spring 4 in a resin pipe connection standby state. . Accordingly, replacement of the resin pipe 1, reworking, and the like are facilitated.

Next, FIG. 9 shows another embodiment of the present joint. This joint includes a joint main body 2, an outer cylindrical body 3, and a coil spring 4. The outer tubular body 3 is fitted around the joint body 2 so as to be rotatable around the axis so as to surround the insertion inner tubular portion 5. Further, the coil spring 4 has an inner end 4 a fixed to the joint body 2, an intermediate portion screwed into the spiral groove 6, and an outer end 4 b fixed to the outer end of the outer cylinder 3. Is being worn. Then, the outer cylindrical body 3 is locked to the joint main body 2 so that the outer cylindrical body 3 can be detached in the rotation direction (rotation locking can be switched), and the coil spring 4 (as shown in FIG.
Is in a resin pipe connection standby state in which the inner diameter Ds of the resin pipe 1 is increased against the elastic force so that the inner diameter Ds of the resin pipe 1 becomes larger than the outer diameter Dp of the resin pipe 1.

More specifically, the outer cylindrical body 3 is rotatably fitted to an intermediate portion of the joint body 2 so as to surround the insertion inner cylindrical portion 5 so as to be fitted externally. The inner end 4a of the coil spring 4 is fixed to the joint body 2, the outer end 4b is fixed to the outer cylinder 3, and the coil spring 4
Is expanded against the elastic force, the outer cylindrical body 3 is axially moved relative to the joint body 2 by the tensile force Fy (the inner diameter Ds is about to be reduced) of the outer end 4b. Try to rotate around. However, a plurality of engaging protrusions 24 provided on the inner end edge of the outer cylindrical body 3 are provided on the outer peripheral surface of the intermediate portion of the joint body 2 (to face the engaging protrusions 24). (Or engagement recesses), so that
The outer cylindrical body 3 maintains the state where the rotational force about the axis is urged, and the coil spring 4 (as shown in FIG.
It will be in the resin pipe connection standby state.

After that, the resin pipe 1 is inserted into the main joint to connect the resin pipe 1. That is, the engaging protrusions 24 of the joint body 2 are made to resist the engaging protrusions 24 of the outer cylindrical body 3 against the tensile force Fx (the height H is about to decrease) of the outer end 4b.
The outer cylinder 3 (with the outer end 4b)
Rotating around the axis, the coil spring 4 (Fig. 3 (c))
As shown in (2), the resin pipe is tightened (connected). The outer cylindrical body 3 does not come out of the joint body 2 in the axial center direction due to the tensile force Fx of the outer end 4b, and is made firm.

When the connected resin pipe 1 is pulled out from the joint, the resin pipe 1 is pulled out against the resilient force of the coil spring 4.
The outer cylinder 3 is rotated around the axis (relative to the joint body 2), and the engagement projections 24 of the outer cylinder 3 are moved to the engagement projections of the joint body 2.
25, the coil spring 4 is brought into the resin pipe connection standby state, and the resin pipe 1 can be pulled out.
Therefore, replacement of the resin pipe 1, re-working, and the like are facilitated, and the number of parts is reduced.

The cross-sectional shape of the coil spring 4 is not limited to a circle but may be an ellipse or a polygon such as a triangle or a quadrangle. Further, as shown in FIG. 10 (a), a plurality of ridges 26 are provided on the outer peripheral surface of the coil spring 4, or as shown in FIG. The ridges 26 may be provided to make the resin pipe 1 bite into the resin pipe 1 so that the resin pipe 1 can be prevented from being pulled out. Note that the ridge portion 26 may be in a fragmentary shape or a continuous shape.

The present invention is not limited to the above embodiment. For example, the coil spring 4 may be wound right or left, and the inner end 4a of the coil spring 4 can be detached. The design may be changed without departing from the spirit of the present invention. Further, the resin pipe tightening mechanism 30 may have various structures other than the illustrated embodiment.

[0035]

The present invention has remarkable effects as described below.

According to the first aspect, the resin pipe 1 can be easily inserted, and the connecting operation can be easily and quickly performed even in a small site. Further, when performing repair or re-work, the resin pipe 1 can be easily detached from the joint body 2 without cutting the resin pipe 1, and the resin pipe 1 can be connected again.

(According to claim 2) The resin pipe 1 can be easily inserted, and the outer end 4b of the coil spring 4
The resin pipe 1 can be easily connected simply by detaching the resin pipe 1 from the outer cylinder 3, and the connection operation can be performed easily and quickly even in a small site. Further, since the connection is made by the elastic force of the coil spring 4 screwed into the spiral groove 6, the resin pipe 1
Of the resin pipe 1 and a stable connection state without rattling can be maintained. Further, when performing repair or re-work, the resin pipe 1 can be easily removed from the joint body 2 without cutting the resin pipe 1, and the resin pipe 1 can be connected again.

According to the third aspect, the resin pipe 1 can be easily inserted, and further, the resin pipe 1 can be easily connected only by detaching the small cylindrical body 18 from the outer cylindrical body 3, and can be easily installed even in a small site. The connection work can be performed quickly. Also,
Because the connection is made by the resilient force of the coil spring 4 screwed into the spiral groove 6, the resin pipe 1 is firmly prevented from coming off, and the uniform force is applied to the entire circumference of the resin pipe 1. It can maintain a stable connection state. Also, when performing repair or re-work, the small pipe 18 is moved around the axis without cutting the resin pipe 1 (with respect to the outer cylinder 3).
By rotating the resin pipe 1, the resin pipe 1 can be easily removed from the joint body 2, and the resin pipe 1 can be connected again.

According to the fourth aspect, the resin pipe 1 can be easily inserted, and further, the resin pipe 1 can be easily connected only by detaching the outer cylindrical body 3 from the joint main body 2. Connection work can be performed quickly. Further, since the connection is made by the resilient force of the coil spring 4 screwed into the spiral groove 6, the resin pipe 1 is firmly prevented from coming off,
In addition, a stable connection state in which an even force is applied to the entire circumference of the resin pipe 1 without rattling can be maintained. Further, when performing repair or re-work, the outer pipe 3 is rotated around the axis (with respect to the joint body 2) without cutting the resin pipe 1 so that the resin pipe 1 can be easily removed from the joint body 2. And the resin pipe 1 can be connected again. In addition, the number of parts is reduced, the assembly is easy, the number of failures is small, and the cost is low.

When the resin pipe 1 is to be pulled out (according to claim 5), the coil springs 4
Is further tightened to prevent the connected resin pipe 1 from coming off.
It will be more robust.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing one embodiment of a resin pipe joint according to the present invention.

FIG. 2 is a side view showing a state where a resin pipe is not inserted.

FIG. 3 is an explanatory diagram of an operation of a coil spring.

FIG. 4 is an explanatory diagram of an operation of a main part.

FIG. 5 is a side sectional view showing a resin pipe connection state.

FIG. 6 is an explanatory diagram of an operation of a main part.

FIG. 7 is a side sectional view showing a resin pipe detached state.

FIG. 8 is a side sectional view showing another embodiment of the joint for a resin pipe.

FIG. 9 is a side sectional view showing another embodiment of the joint for a resin pipe.

FIG. 10 is a cross-sectional view illustrating another embodiment of the coil spring.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Resin pipe 2 Joint main body 3 Outer cylinder 4 Coil spring 4a Inner end 4b Outer end 5 Inserting inner cylinder 6 Spiral groove 7 Outer peripheral surface 8 Spiral ridge 17 Tapered surface 18 Small cylinder 30 Tightening resin pipe Mechanism Ds Inner diameter Dp Outer diameter

 ──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Keiji Matsumoto 8-22 Kikusuicho, Kawachinagano City F-term in Higashio Mec Co., Ltd. 3H017 CA03

Claims (5)

[Claims] 1. A joint body 2 having an insertion inner cylinder portion 5 having a spiral projection 8 provided on an outer peripheral surface 7 inserted into a resin pipe 1 so as to surround the insertion inner cylinder portion 5. A resin pipe tightening mechanism (30) externally fitted to the joint body (2) and tightening the resin pipe (1). 2. A joint body 2 having an insertion inner cylindrical portion 5 provided with a spiral ridge 8 on an outer peripheral surface 7 inserted into the resin pipe 1; and a helical groove 6 on an inner peripheral surface. An outer cylindrical body 3 fitted to the joint body 2 so as to surround the inner cylindrical part 5; an inner end 4a is fixed to an inner end side of the outer cylindrical body 3; It is screwed into the spiral groove 6, and furthermore, the outer end 4b is detachably locked to the outer end side of the outer cylindrical body 3 so that the inner diameter Ds becomes larger than the outer diameter Dp of the resin pipe 1. And a coil spring 4 having an inner diameter Ds smaller than the outer diameter Dp of the resin pipe 1 in a free state. 3. A joint body 2 having an insertion inner cylindrical portion 5 provided with a spiral ridge portion 8 on an outer peripheral surface 7 inserted into the resin pipe 1; An outer cylinder body 3 externally fitted to the joint main body 2 so as to surround the inner cylinder part 5; a small cylinder body 18 rotatably connected to the outer end side of the outer cylinder body 3 so as to be rotatable around an axis; And the inner end portion 4a is fixed to the inner end side of the outer cylindrical body 3 and the intermediate portion is screwed into the spiral groove 6,
Further, the outer end portion 4b is fixed to the outer end side of the small cylindrical body 18, and the small cylindrical body 18 is locked to the outer cylindrical body 3 so as to be able to switch the rotation and locking, so that the inner diameter Ds A coil spring 4 having an inner diameter Ds smaller than the outer diameter Dp of the resin pipe 1 in a free state, which is expanded against the elastic force so as to be larger than the outer diameter Dp of the resin pipe 1; A resin pipe joint characterized by comprising: 4. A joint body 2 having an insertion inner cylindrical portion 5 provided with a spiral ridge portion 8 on an outer peripheral surface 7 inserted into the resin pipe 1; An outer cylindrical body 3 rotatably fitted around the joint main body 2 around the axis so as to surround the inner cylindrical part 5; an inner end 4a is fixed to the joint main body 2; Is screwed into the spiral groove 6, the outer end portion 4b is fixed to the outer end side of the outer cylindrical body 3, and the outer cylindrical body 3 can be rotationally switched to the joint main body 2. The outer diameter Dp of the resin pipe 1 in a free state is expanded in such a manner that the inner diameter Ds is larger than the outer diameter Dp of the resin pipe 1 in a free state.
A coil spring 4 having an inner diameter Ds smaller than;
A resin pipe joint characterized by comprising: 5. The spiral groove 6 on the inner peripheral surface of the outer cylindrical body 3 has a tapered surface portion 17 whose diameter is reduced outward.
Or the joint for resin pipes according to 4.