JP6870938B2 - Connection structure and connection method of hard resin pipe - Google Patents

Description

The present invention relates to a tube connection structure and a connection method in which the insertion port of one tube is inserted into the socket of the other tube, and in particular, a fiber reinforced plastic tube (hereinafter referred to as "FRP tube") or a fiber reinforced plastic composite. The present invention relates to a structure and a connecting method for connecting hard resin pipes such as pipes (hereinafter referred to as “FRPM pipes”).

Generally, an insertion port is formed at one end of a hard resin tube such as an FRP tube or an FRPM tube, and a socket is formed at the other end. When connecting two hard resin pipes, the insertion port of one hard resin pipe is inserted into the receiving port of the other hard resin pipe. There are B type and C type in the connection method of this kind of hard resin pipe. In the B type, an annular sealing member is provided on the outer peripheral surface of the tip end portion of the insertion port to seal between the inner peripheral surface of the receiving port. In the C type, an annular sealing member is provided on the inner peripheral surface of the tip end portion of the receiving port to seal between the sealing member and the outer peripheral surface of the insertion port.

When an earthquake or an increase in the pressure inside the pipe occurs, a pulling force acts between the hard resin pipes, and there is a risk that the connection between these hard resin pipes will be disconnected. In order to prevent this, in both the B type and the C type, an insertion side detachment prevention member is provided on the outer peripheral surface of the insertion port, and a receiving side detachment prevention member is provided on the inner peripheral surface of the receiving port. (See Patent Document 1 etc.). When connecting the hard resin pipes to each other, it is necessary that the detachment prevention member on the side of the insertion port and the receiving port where the seal member is not provided overcomes the seal member and further overcomes the detachment prevention member on the other side.

Japanese Unexamined Patent Publication No. 2001-263557

Since a resin pipe such as a normal polyolefin resin pipe or a vinyl chloride pipe can be elastically deformed, it is not so difficult for each detachment prevention member to get over the seal member and further over the other side detachment prevention member. However, since a hard resin tube such as an FRP tube hardly elastically deforms, it is necessary to apply a large insertion force at the time of connection. If the insertion force is too large, the hard resin tube may be damaged or the sealing member may be damaged.
In view of the above circumstances, it is an object of the present invention to provide a hard resin pipe connection structure and a connection method capable of improving the connection workability of the hard resin pipe and preventing or reducing damage to the sealing member.

In order to solve the above problems, the present invention has a hard resin tube connecting structure including one hard resin tube having an insertion port and the other hard resin tube having a receiving port for receiving the insertion port.
An annular sealing member provided on the outer peripheral surface of the insertion port and sealing between the inner peripheral surface of the receiving port, and an annular sealing member.
An insertion side detachment prevention member provided on the outer peripheral surface of the insertion port on the tip side of the insertion opening with respect to the seal member at the insertion port,
The receiving side detachment prevention member provided on the inner peripheral surface of the receiving port and
The receiving side detachment prevention member in the connected state between the hard resin pipes is arranged between the insertion side detachment prevention member and the seal member.

According to the present invention, in the B-shaped hard resin pipe connecting structure, when connecting the receiving port and the insertion port, it is not necessary for the receiving side detachment prevention member of the receiving port to get over the sealing member of the insertion port. Thereby, damage to the sealing member can be prevented or reduced. In addition, the insertion force or the amount of work when connecting the hard resin pipe can be reduced, and the connection workability of the hard resin pipe can be improved. When a pulling force acts due to an earthquake or the like, the insertion side detachment prevention member and the receiving side detachment prevention member abut each other and are locked, thereby preventing the insertion opening and the receiving port from coming off, and eventually a hard resin pipe. You can prevent them from coming off.
Here, the hard resin refers to a resin having a hardness higher than that of a general polyolefin resin or polyvinyl chloride. The elastic modulus of the hard resin is preferably 30,000 kgf / cm ² (3000 MPa) or more.

It is preferable that at least one of the insertion-side detachment prevention member and the receiving-side detachment prevention member is more elastic than the hard resin tube.
As a result, the insertion force when the detachment prevention members get over each other can be surely reduced.

It is preferable that the insertion side detachment prevention member is adhered to or can be adhered to the insertion port.
As a result, the insertion side detachment prevention member can be manufactured separately from the insertion opening and attached to the insertion opening. The insertion side detachment prevention member may be adhered to the insertion port before the rigid resin pipes are connected to each other.
When inserting the insertion slot into the socket, the insertion side detachment prevention member may be separated from the insertion slot, and the insertion side detachment prevention member may be adhered to the insertion slot after insertion. That is, the insertion side detachment prevention member may be adhereable to the insertion opening. In this case, when the insertion port is inserted into the receiving port, it is not necessary for the receiving side detachment prevention member and the insertion side detachment prevention member to get over each other, and the required insertion force can be reliably reduced. As a result, the connection workability of the hard resin pipe can be improved.

The insertion side detachment prevention member may be fixed to the insertion opening by a mechanical fixing means such as a screw.
The insertion side detachment prevention member may be integrated with the insertion port. A molding portion of the insertion side detachment prevention member may be provided in the molding die of the insertion port so that the insertion side detachment prevention member is integrally molded with the insertion port.

The receiving side detachment prevention member may be manufactured separately from the receiving port and attached to the receiving port. The receiving side detachment prevention member may be adhered to the receiving port, or may be fixed by a mechanical fixing means such as a screw.
The receiving side detachment prevention member may be integrated with the receiving port. A molding portion of the receiving side detachment prevention member may be provided in the molding die of the receiving port so that the receiving side detachment preventing member is integrally molded with the receiving port.

A fitting groove is formed on one of the outer peripheral surface of the insertion port and the inner peripheral surface of the insertion side detachment prevention member.
It is preferable that a fitting projection to be fitted into the fitting groove is formed on the other of the outer peripheral surface of the insertion port and the inner peripheral surface of the insertion side detachment prevention member.
As a result, the joint strength between the insertion side detachment prevention member and the insertion port can be increased. Further, the locking strength at the time of the action of the pulling force can be increased.

The outer peripheral surface on the tip end side of the insertion slot is tapered so that the diameter of the outer peripheral surface on the tip end side of the insertion slot is reduced toward the tip end of the insertion slot.
It is preferable that the inner peripheral surface of the insertion side detachment prevention member has a tapered shape that expands in diameter toward the arrangement portion.
As a result, even if the insertion side detachment prevention member is made of a hard material such as metal or hard resin, the inner peripheral surface of the insertion side detachment prevention member and the outer peripheral surface of the insertion port can be reliably brought into close contact with each other. It is not necessary to set the clearance between the inner peripheral surface of the insertion side detachment prevention member and the outer peripheral surface of the insertion port with high accuracy.

It is preferable that the insertion side detachment prevention member is removable from the insertion opening.
As a result, when the insertion port is inserted into the receiving port, the insertion side detachment prevention member can be separated from the insertion opening. By doing so, it is not necessary for the receiving side detachment prevention member and the insertion side detachment prevention member to overcome each other, and the insertion force at the time of connecting the hard resin pipes can be significantly reduced. Further, even after the connection is made once, the hard resin pipes can be separated from each other by removing the insertion side detachment prevention member, and the connection work can be redone.

The insertion side detachment prevention member may be expandable or contractable by forming an annular shape having a notch at one position in the circumferential direction.
As a result, the insertion side detachment prevention member can be brought into close contact with the outer peripheral surface of the insertion opening by expanding the diameter and arranging it on the outer periphery of the insertion opening, and then releasing the diameter expansion and reducing the diameter. The installation work can be further facilitated.

The method of the present invention is a method of connecting the hard resin pipes to each other.
With the insertion side detachment prevention member removed from the insertion slot, the insertion slot is inserted into the socket.
After that, the insertion side detachment prevention member is attached to the insertion opening.
According to the method of the present invention, when the insertion port is inserted into the receiving port, it is not necessary for the receiving side detachment prevention member and the insertion side detachment prevention member to get over each other, and the required insertion force can be significantly reduced. As a result, the connection workability of the hard resin pipe can be improved. The mounting step may be performed by the operator inside the hard resin pipe, or may be performed by using a dedicated jig or device.

According to the present invention, the connection workability of the hard resin pipe can be improved, and damage to the sealing member can be prevented or reduced.

FIG. 1 is a front view showing a hard resin pipe connection structure according to a first embodiment of the present invention in a connected state between two hard resin pipes. FIG. 2 is a plan sectional view of a rigid resin pipe connecting structure in the connected state along the line II-II of FIG. FIG. 3 is a plan sectional view showing the insertion port and the receiving port of the hard resin pipe connection structure in a state before connection. 4 (a) to 4 (c) are cross-sectional views showing sequentially the steps of connecting the hard resin pipes to each other. FIG. 5 is a cross-sectional view showing a state when a pulling force acts on the two hard resin pipes. FIG. 6 is a plan sectional view of a hard resin pipe connection structure according to a second embodiment of the present invention. FIG. 7 is a plan sectional view showing a rigid resin pipe connection structure according to a third embodiment of the present invention in a state before connection between the insertion port and the receiving port. 8 (a) to 8 (c) are plan sectional views showing sequentially the connecting steps of the hard resin pipes in the hard resin pipe connecting structure according to the third embodiment. 9 (a) and 9 (b) are plan sectional views showing sequentially the connecting steps of the hard resin pipes in the hard resin pipe connecting structure according to the fourth embodiment of the present invention. 10 (a) and 10 (b) are plan sectional views showing sequentially the connecting steps of the hard resin pipes in the hard resin pipe connecting structure according to the fifth embodiment of the present invention. FIG. 11 is a perspective view of the insertion side detachment prevention member according to the sixth embodiment of the present invention. 12 (a) to 12 (c) are cross-sectional views showing sequentially the connecting steps of the hard resin pipes in the hard resin pipe connecting structure according to the sixth embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<First Embodiment>
1 to 5 show the first embodiment of the present invention. As shown in FIG. 1, the embodiment of the present invention relates to the connection structure 1 of a plurality of hard resin pipes 10 (only two are shown in the figure). These hard resin pipes 10 are arranged in a row and are provided as, for example, a sewer pipe, an agricultural water pipe, or the like. Each hard resin tube 10 is made of a hard resin such as FRP or FRPM.

An insertion port 13 is provided at one end (right end in FIG. 1) of each hard resin tube 10, and a receiving port 12 is provided at the other end (left end in FIG. 1). As shown in FIGS. 1 and 2, of the two adjacent hard resin pipes 10, the insertion port 13 of one of the hard resin pipes 10A (on the left side in the figure) is connected to the socket 12 of the other hard resin pipe 10B. By being accepted, these hard resin tubes 10A and 10B are connected to each other.
In the following description, unless otherwise specified, the insertion port 13 refers to the hard resin tube 10A, and the receiving port 12 refers to the hard resin tube 10B.

As shown in FIG. 3, a sealing member 14 is provided at the insertion port 13. Therefore, the hard resin pipe connection structure 1 is B-shaped. The seal member 14 is made of rubber or the like and has an annular shape. The outer diameter of the sealing member 14 in the natural state is larger than the inner diameter of the receiving port 12. As shown in FIG. 2, when the hard resin pipes 10 are connected to each other, the sealing member 14 is compressed and brought into close contact with the entire inner peripheral surface of the receiving port 12, so that the insertion port 13 and the receiving port 12 are brought into close contact with each other. Is sealed between.

As shown in FIG. 2, the hard resin pipe connecting structure 1 is provided with means 15 for preventing detachment between the hard resin pipes 10. The detachment prevention means 15 includes an insertion side detachment prevention member 30 and a receiving side detachment prevention member 20. As shown in FIG. 3, the insertion port 13 is provided with the insertion side detachment prevention member 30, and the receiving port 12 is provided with the receiving side detachment prevention member 20.

These detachment prevention members 20 and 30 are separate from the hard resin pipe 10. The detachment prevention members 20 and 30 are made of a resin having appropriate elasticity and hardness. At least one of the detachment prevention members 20 and 30 is more elastic than the hard resin tube 10. One of the detachment prevention members 20 and 30 may be harder than the other, and may be as hard as or harder than the hard resin pipe 10. Either one of the detachment prevention members 20 and 30 may be made of a hard resin such as FRP or FRPM, or may have a laminated structure of FRP.

As shown in FIG. 3, the insertion side detachment prevention member 30 is arranged on the insertion opening tip 13e side (right side in FIG. 3) with respect to the seal member 14 in the insertion opening 13. Preferably, the insertion side detachment prevention member 30 is arranged near the insertion opening tip 13e.

The insertion side detachment prevention member 30 has a tubular shape or an annular shape. The tip surface of the insertion side detachment prevention member 30 facing the side opposite to the seal member 14 (right side in FIG. 3) is flush with the insertion tip 13e. The inner peripheral surface of the insertion side detachment prevention member 30 is a straight cylindrical surface. The outer peripheral surface of the insertion side detachment prevention member 30 has a tapered shape that gradually expands in diameter toward the seal member 14 side (left side in FIG. 3). The thickness of the insertion side detachment prevention member 30 increases toward the seal member 14 side.
The thickness of the insertion side detachment prevention member 30 may be constant over the entire length.

The insertion side detachment prevention member 30 and the insertion port 13 are adhered to each other via an adhesive (details are not shown). As the adhesive, various adhesives such as an epoxy adhesive and a urethane adhesive can be applied. Instead of the adhesive, or in addition to the adhesive, the insertion side detachment prevention member 30 and the insertion port 13 may be fixed by mechanical fixing means such as screwing. When the insertion side detachment prevention member 30 has an FRP laminated structure, it is preferable that the insertion port 13 is sanded and then laminated.

As shown in FIG. 3, the receiving side detachment prevention member 20 is arranged on the inner peripheral surface of the receiving port 12 away from the receiving side tip 12e in the receiving port 12 (on the right side in FIG. 3). The receiving side detachment prevention member 20 has a tubular shape or an annular shape. The outer peripheral surface of the receiving side detachment prevention member 20 is a straight cylindrical surface. The inner peripheral surface of the receiving side detachment prevention member 20 has a tapered shape that gradually expands in diameter toward the receiving port tip 12e side (left side in FIG. 3). The thickness of the receiving side detachment prevention member 20 decreases toward the receiving port tip 12e.
The thickness of the receiving side detachment prevention member 20 may be constant over the entire length.

The receiving side detachment prevention member 20 and the receiving port 12 are adhered to each other via an adhesive (details are not shown). As the adhesive, various adhesives such as an epoxy adhesive and a urethane adhesive can be applied. Instead of the adhesive, or in addition to the adhesive, the receiving side detachment prevention member 20 and the receiving port 12 may be fixed by mechanical fixing means such as screwing. When the receiving side detachment prevention member 20 has an FRP laminated structure, it is preferable that the receiving port 12 is sanded and then laminated.

As shown in FIG. 2, when the two hard resin tubes 10A and 10B are connected to each other, the insertion side detachment prevention member 30 and the receiving side detachment prevention member 20 are formed on the outer peripheral surface of the insertion port 13 and the inner circumference of the receiving port 12. It is arranged in an annular clearance (gap) between the surfaces. Further, in the axial direction of the hard resin pipe 10, the receiving side detachment prevention member 20 is arranged between the insertion side detachment prevention member 30 and the seal member 14. Preferably, the receiving side detachment prevention member 20 is arranged farther from the sealing member 14 to the insertion tip 13e side (right side in FIG. 2) and is not in contact with the sealing member 14. Further, the outer diameter of the insertion side detachment prevention member 30> the inner diameter of the receiving side detachment prevention member 20.
When a force in the detachment direction acts on the resin tube 10, a force in the compression direction may be applied to the insertion side detachment prevention member 30 and the receiving side detachment prevention member 20 to deform, but the seal member 14 is deformed because no load is applied. It will not be damaged.

<How to connect the hard resin pipe 10>
The two hard resin pipes 10 are connected to each other as follows.
The insertion side detachment prevention member 30 and the seal member 14 are installed in the insertion port 13 in advance, and the receiving side detachment prevention member 20 is installed in the receiving port 12.
As shown in FIG. 4A, the hard resin tubes 10 are arranged in a straight line, and the insertion port 13 is inserted into the receiving port 12.
As shown in FIG. 4B, the detachment prevention members 20 and 30 eventually hit each other. Here, by applying a strong insertion force, the detachment prevention members 20 and 30 are allowed to overcome each other. By making at least one of the detachment prevention members 20 and 30 made of an elastic material, the detachment prevention member can be elastically deformed. Therefore, the required insertion force can be reduced. Further, since the inner peripheral surface of the receiving side detachment prevention member 20 and the outer peripheral surface of the insertion side detachment prevention member 30 are tapered, the insertion can be made easier.

As shown in FIG. 4C, the receiving side detachment prevention member 20 is positioned between the insertion side detachment prevention member 30 and the seal member 14 by the overcoming. Further, the portion of the receiving port 12 on the receiving side tip 12e side (left side in the figure) of the receiving side detachment prevention member 20 is pressed against the seal member 14. As a result, the connection operation between the hard resin pipes 10 is completed. It is not necessary for the receiving side detachment prevention member 20 to get over the seal member 14. Therefore, the insertion force needs to be increased only when the insertion side detachment prevention member 30 gets over the receiving side detachment prevention member 20, and the amount of work at the time of connection can be reduced. It is only necessary to apply a load to the seal member 14 by pressure contact with the receiving port 12, and damage to the seal member 14 can be prevented or reduced.

As shown in FIG. 5, when a pull-out force F acts on the hard resin pipes 10A and 10B due to an earthquake or an increase in the pipe pressure, the hard resin pipes 10A and 10B are displaced relative to each other in the pulling direction. , The receiving side detachment prevention member 20 abuts against the insertion side detachment prevention member 30 and is locked. As a result, it is possible to prevent the hard resin tubes 10A and 10B from coming off from each other.

Next, other embodiments of the present invention will be described. In the following embodiments, the same reference numerals are given to the drawings for configurations that overlap with the above-described embodiments, and the description thereof will be omitted.
<Second Embodiment>
FIG. 6 shows a second embodiment of the present invention. In the hard resin pipe connection structure 1B according to the second embodiment, the insertion port 13 and the insertion side detachment prevention member 30B are unevenly fitted. Specifically, the fitting groove 13b is formed on the outer peripheral surface of the insertion port 13 in the vicinity of the insertion port tip 13e. The fitting groove 13b has an annular shape over the entire circumference of the insertion port 13 in the circumferential direction. A fitting protrusion 33 is formed on the inner peripheral surface of the insertion side detachment prevention member 30B. The fitting projection 33 has an annular shape over the entire circumference of the insertion side detachment prevention member 30B in the circumferential direction. The fitting protrusion 33 is fitted into the fitting groove 13b.
As a result, the joint strength between the insertion side detachment prevention member 30B and the insertion port 13 can be increased. As a result, the locking strength at the time of action of the pull-out force F (see FIG. 5) can be increased.

<Third Embodiment>
7 and 8 show a third embodiment of the present invention. As shown in FIG. 7, in the hard resin pipe connection structure 1C according to the third embodiment, the insertion side detachment prevention member 30C is manufactured separately from the insertion port 13 and can be adhered to the insertion port 13. .. That is, the insertion side detachment prevention member 30C can be attached to the insertion port 13 after the insertion port 13 and the receiving port 12 are fitted to each other.

The receiving side detachment prevention member 20 of the hard resin pipe connecting structure 1C has a straight cylindrical shape having a constant thickness over the entire length. The insertion side detachment prevention member 30C has a straight cylindrical shape having a constant thickness over the entire length.
The inner peripheral surface of the receiving side detachment prevention member 20 and the outer peripheral surface of the insertion side detachment prevention member 30 may have the same tapered shape as in the first embodiment (FIG. 2).

As shown in FIG. 7, in the third embodiment, the insertion side detachment prevention member 30C is separated from the insertion port 13 before the hard resin tubes 10A and 10B are joined to each other. The separated insertion side detachment prevention member 30C may be arranged inside the hard resin tube 10B.
As shown in FIG. 8A, the insertion port 13 is inserted into the receiving port 12 in that state. As a result, as shown in FIG. 8B, the insertion port 13 is inserted into the receiving side detachment prevention member 20, and the seal member 14 is pressed against the inner peripheral surface of the receiving port 12. Since the insertion opening 13 is not provided with the insertion side detachment prevention member 30C, it is not necessary for the detachment prevention members 20 and 30C to overcome each other, and the required insertion force can be significantly reduced.

As shown in FIG. 8B, after the insertion port 13 is inserted into the receiving port 12 until the receiving side detachment prevention member 20 comes to a predetermined position near the seal member 14, the receiving side detachment prevention member in the insertion port 13 An adhesive (not shown) is applied to the outer peripheral surface of the insertion port tip 13e side of the 20. Alternatively, an adhesive may be applied to the inner peripheral surface of the insertion side detachment prevention member 30C.
Subsequently, as shown in FIG. 8C, the insertion side detachment prevention member 30C is fitted to the outer periphery of the insertion opening tip 13e side of the receiving side detachment prevention member 20 in the insertion opening 1. As a result, the receiving side detachment prevention member 20 is arranged between the seal member 14 and the insertion side detachment prevention member 30C. It is not necessary for the receiving side detachment prevention member 20 to get over the seal member 14, and damage to the seal member 14 can be prevented or reduced.
The insertion side detachment prevention member 30C may be fitted into the insertion port 13 by an operator inside the hard resin pipe 10 or by using a dedicated jig or device. After that, the insertion side detachment prevention member 30C and the insertion port 13 are adhered by curing until the adhesive is cured. As the adhesive, a void-filling adhesive may be used.

<Fourth Embodiment>
FIG. 9 shows a fourth embodiment of the present invention. The fourth embodiment is a combination of the retrofitting method of the third embodiment (FIGS. 7 and 8) and the uneven fitting of the second embodiment (FIG. 6). That is, in the hard resin pipe connection structure 1D of the fourth embodiment, the insertion side detachment prevention member 30D can be attached to the insertion port 13 after the insertion port 13 and the receiving port 12 are fitted to each other. In addition, a fitting projection 33 is formed on the inner peripheral surface of the insertion side detachment prevention member 30D. A fitting groove 13b is formed on the outer peripheral surface of the insertion port 13.

As shown in FIG. 9A, when the insertion port 13 is inserted into the receiving port 12, the insertion side detachment prevention member 30D is separated from the insertion port 13. Therefore, it is not necessary for the detachment prevention members 20 and 30D to overcome each other, and the required insertion force can be significantly reduced.
As shown in FIG. 9B, after the insertion port 13 is inserted, the insertion side detachment prevention member 30D is fitted into the outer circumference of the insertion port 13. At this time, the fitting protrusion 33 is press-fitted because it interferes with the insertion port 13, but the insertion force is compared with the case where the detachment prevention members 20 and 30 get over each other (FIG. 4B, etc.). Can be significantly reduced. A striking jig or the like may be used for press fitting.

As shown in FIG. 9B, the fitting protrusion 33 eventually fits into the fitting groove 13b. As a result, the insertion side detachment prevention member 30D can be positioned and arranged on the outer peripheral surface of the insertion port 13. Moreover, the joint strength between the insertion side detachment prevention member 30D and the insertion port 13 can be increased. Further, when the pulling force F (see FIG. 5) acts, a sufficient locking force can be secured against the pulling force F (see FIG. 5).
Further, the insertion port 13 and the insertion side detachment prevention member 30D may be adhered with an adhesive. As the adhesive, a void-filling adhesive may be used.

<Fifth Embodiment>
FIG. 10 shows a fifth embodiment of the present invention. The fifth embodiment relates to a modified mode of the third embodiment (FIG. 8) in which the insertion side detachment prevention member is retrofitted. In the hard resin tube connection structure 1E, a tapered portion 13a is formed on the outer peripheral surface of the insertion port tip 13e side (right side in FIG. 10A) with respect to the arrangement portion of the receiving side detachment prevention member 20 in the insertion port 13. .. The tapered portion 13a is gradually reduced in diameter toward the insertion tip 13e and reaches the insertion tip 13e. The tip end side portion of the insertion slot 13 becomes thinner toward the insertion slot tip 13e.

The insertion side detachment prevention member 30E is made of metal (hard material). The insertion side detachment prevention member 30E may be made of a hard resin such as FRP or FRPM. The inner peripheral surface of the insertion side detachment prevention member 30E is a tapered portion 36. The diameter of the tapered portion 36 is gradually increased toward the arrangement side (left side in FIG. 10A) of the receiving side detachment prevention member 20. Therefore, the insertion side detachment prevention member 30E becomes thinner toward the arrangement side of the receiving side detachment prevention member 20. The angle of the tapered portion 36 coincides with the angle of the tapered portion 13a. In FIG. 10, the inclination angles of the tapered portions 36 and 13a are exaggerated.

As shown in FIG. 10A, when the insertion port 13 is inserted into the receiving port 12, the insertion side detachment prevention member 30E is separated from the insertion port 13. Therefore, it is not necessary for the detachment prevention members 20 and 30E to overcome each other, and the required insertion force can be significantly reduced.
As shown in FIG. 10B, after the insertion port 13 is inserted, the insertion side detachment prevention member 30E is fitted into the outer circumference of the insertion port 13. Since the inner peripheral surface of the insertion side detachment prevention member 30E and the outer peripheral surface of the insertion port 13 are both tapered portions 36 and 13a, the insertion side detachment prevention member 30E and the insertion port 13 can be brought into close contact with each other over the entire circumference. .. Even if the insertion side detachment prevention member 30E is made of a hard material such as metal or hard resin, the insertion side detachment prevention member 30E and the insertion port 13 can be reliably brought into close contact with each other. Therefore, it is not necessary to set the clearance between the inner peripheral surface of the insertion side detachment prevention member 30E and the outer peripheral surface of the insertion port 13 with high accuracy.
The insertion side detachment prevention member 30E and the insertion port 13 are adhered with an adhesive. As the adhesive, a void-filling adhesive may be used.

<Sixth Embodiment>
11 and 12 show a sixth embodiment of the present invention. The sixth embodiment relates to a modified mode of the third embodiment (FIG. 8) in which the insertion side detachment prevention member is retrofitted. As shown in FIG. 11, in the hard resin pipe connection structure 1F of the sixth embodiment, the insertion side detachment prevention member 30F has an annular shape (C shape) having a notch 35 at one position in the circumferential direction. .. The material of the insertion side detachment prevention member 30F is made of a metal (hard material) such as iron, steel, or stainless steel. Preferably, the insertion side detachment prevention member 30F is made of spring steel. The insertion side detachment prevention member 30F may be made of FRP or other hard resin instead of metal.

The insertion-side detachment prevention member 30F can be expanded or contracted by applying a diameter-expanding force or a diameter-reducing force. The inner diameter of the insertion side detachment prevention member 30F in the natural state (the no-load state in which the diameter expansion force or the diameter reduction force is not applied) is preferably smaller than the outer diameter of the insertion port 13. Moreover, the outer diameter of the insertion side detachment prevention member 30F in the natural state is preferably smaller than the inner diameter of the receiving port 12. The insertion side detachment prevention member 30F may be detachable from the insertion opening 13.

A fitting protrusion 33 is formed on the inner peripheral surface of the insertion side detachment prevention member 30F. The fitting projection 33 extends along the circumferential direction of the insertion side detachment prevention member 30F.
As shown in FIG. 12, a fitting groove 13b is formed on the outer peripheral surface of the insertion port 13. The fitting groove 13b has a closed ring shape along the circumferential direction of the insertion port 13.

As shown in FIG. 12A, when the hard resin pipes 10 are connected to each other, the insertion side detachment prevention member 30F is separated from the insertion port 13. Then, the insertion port 13 is inserted into the receiving port 12, and the receiving side detachment prevention member 20 is arranged between the seal member 14 and the fitting groove 13b. It is not necessary for the receiving side detachment prevention member 20 to get over the seal member 14. Therefore, damage to the seal member 14 can be suppressed or prevented.

Subsequently, as shown in FIG. 12B, the insertion side detachment prevention member 30F is fitted on the outer circumference of the insertion port 13. At this time, the diameter of the insertion side detachment prevention member 30F is increased to increase the width of the notch 35. As a result, it is possible to prevent the fitting protrusion 33 from interfering with the insertion port 13. Alternatively, the degree of interference between the fitting protrusion 33 and the insertion port 13 can be reduced, and the required pressure input can be reduced. Therefore, the insertion operation of the insertion side detachment prevention member 30F can be easily performed.

When the fitting protrusion 33 reaches a position corresponding to the fitting groove 13b, the diameter expansion of the insertion side detachment prevention member 30F is released. As a result, the diameter of the insertion side detachment prevention member 30F is reduced by the elastic restoring force, the inner peripheral surface of the insertion side detachment prevention member 30F is brought into close contact with the outer peripheral surface of the insertion port 13, and the fitting projection 33 is brought into contact with the fitting groove 13b. Fits in. Therefore, the insertion side detachment prevention member 30F can be prevented from coming off from the insertion port 13.

The insertion side detachment prevention member 30F is removable from the insertion port 13 even after the rigid resin pipes 10 are connected to each other. Therefore, if there is a problem with the connection, the insertion side detachment prevention member 30F can be removed from the insertion port 13 by increasing the diameter of the insertion side detachment prevention member 30F. As a result, the hard resin tubes 10 can be separated from each other. As a result, the connection construction can be redone.

The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the second embodiment (FIG. 6) or the like, the fitting projection 33 may be provided in the insertion port 13, and the fitting groove 13b may be provided in the insertion side detachment prevention member 30B.
Multiple embodiments may be combined with each other. For example, the insertion side detachment prevention member 30F may be installed in the insertion port 13 and then adhered with an adhesive.

The present invention can be applied to, for example, a joint structure of a sewer pipe or an agricultural water pipe.

1,1B to 1F Hard resin pipe connection structure 10 Hard resin pipe 10A One hard resin pipe 10B The other hard resin pipe 12 Receiving port 12e Receiving port tip 13 Insertion port 13a Tapered part 13b Fitting groove 13e Insertion tip 14 Sealing member 20 Receiving side detachment prevention member 30, 30B to 30F Insertion side detachment prevention member 33 Fitting protrusion 35 Notch 36 Tapered portion

Claims (2)

It is a hard resin pipe connection structure including one hard resin pipe having an insertion port and the other hard resin tube having a receiving port for receiving the insertion port.
An annular sealing member provided on the outer peripheral surface of the insertion port and sealing between the inner peripheral surface of the receiving port, and an annular sealing member.
An insertion side detachment prevention member provided on the outer peripheral surface of the insertion port on the tip side of the insertion opening with respect to the seal member at the insertion port,
The receiving side detachment prevention member provided on the inner peripheral surface of the receiving port and
The receiving side detachment prevention member in the connected state between the hard resin pipes is arranged between the insertion side detachment prevention member and the seal member.
The outer peripheral surface of the insertion port has the same diameter as the cylindrical portion having a constant diameter including the arrangement portion of the receiving side detachment prevention member in the connected state and the end portion of the cylindrical portion on the insertion port tip side. Includes a tapered tapered portion that is continuous and shrinks toward the tip of the insertion slot.
The inner peripheral surface of the insertion-side detachment prevention member has a tapered shape that expands toward the arrangement portion at the same inclination angle as the taper portion and reaches the end surface of the insertion-side detachment prevention member facing the arrangement portion. A hard resin pipe connecting structure, wherein the insertion side detachment prevention member is arranged in the tapered portion and adhered to the tapered portion. One hard resin tube having an insertion port provided with an insertion side detachment prevention member and an annular seal member on the outer peripheral surface, and the other hard resin tube having a socket provided with a receiving side detachment prevention member on the inner peripheral surface. Is a method in which the receiving port receives the insertion port and the receiving side detachment prevention member is arranged between the insertion side detachment prevention member and the seal member. ,
With the insertion side detachment prevention member removed from the insertion opening, a portion of the insertion opening on the tip side of the insertion opening from the seal member is inserted into the receiving port, and further inserted into the receiving side detachment prevention member.
After that, the insertion side detachment prevention member is attached to the outer periphery of the portion on the insertion end end side of the insertion opening that has passed through the receiving side detachment prevention member.
The outer peripheral surface on the tip end side of the insertion slot is tapered so that the diameter of the outer peripheral surface on the tip end side of the insertion slot is reduced toward the tip end of the insertion slot.
A method for connecting a hard resin tube, characterized in that the inner peripheral surface of the insertion side detachment prevention member has a tapered shape that expands in diameter toward the arrangement portion.

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