JP2023008547A - Jig, pipe fusion structure, and pipe fusion method - Google Patents

Abstract

To obtain a jig capable of improving productivity.SOLUTION: A jig 10 comprises: a cylindrical main body portion 10A that is inserted into a first pipe 12 and a second pipe 14 made of thermoplastic resin and that has an outer peripheral surface in contact with an inner peripheral surface of the resin pipe; and a taper-shaped return portion 10B that is provided at both ends in the longitudinal direction of the main body portion 10A, has a maximum diameter larger than an outer diameter of the main body portion 10A, and decreasing in diameter toward a tip side of the body portion 10A.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a jig, a pipe fusion structure, and a pipe fusion method used when resin pipes are fused together.

As a method of joining resin pipes made of thermoplastic resin, there is a method of joining by fusion (for example, see Patent Document 1).

JP-A-9-144977

However, when two resin pipes are fused together, a period for curing the resin pipes, that is, a cooling period (for example, several minutes) is required until the molten resin is cooled and solidified. For this reason, when the welding work is performed in the process of the factory, the line is stopped each time, and there is a problem that the production efficiency is lowered, and there is room for improvement.

SUMMARY OF THE INVENTION In view of the above facts, an object of the present invention is to provide a jig, a pipe welding structure, and a pipe welding method that can improve productivity.

The invention according to claim 1 is a jig used when resin pipes made of thermoplastic resin are fused to each other, and comprises a cylindrical body portion inserted into the resin pipe, and a body portion of the body portion. Tapered return portions are provided at both ends in the longitudinal direction, and have a maximum diameter larger than the outer diameter of the main body portion, the diameter of which decreases toward the tip side of the main body portion.

In the jig according to claim 1, the end portion of the main body portion to be inserted into the resin pipe has a tapered shape with a maximum diameter larger than the outer diameter of the main body portion and a diameter decreasing toward the tip side of the main body portion. A return portion is formed. Therefore, when the main body portion of the jig is inserted into the resin pipe, it is possible to prevent the return portion from being caught on the inner peripheral surface of the pipe and the pipe from coming off the jig.

A jig can be used, for example, when joining resin pipes by fusion.
As an example, as a process of joining resin pipes by fusion bonding, the end portion of one pipe and the other end portion are heated to melt the surface, and one side of a jig is inserted into one pipe. At the same time, the other side of the jig is inserted into the other pipe to bring the melted portion of one pipe into contact with the melted portion of the other pipe for fusion bonding.

If the pipes are moved in a state where the melted portion of the pipe is not solidified without using a jig, the pipes may be separated from each other, or a fusion failure (bonding failure) may occur at the fusion-bonded portion. If no jig is used, it is necessary to cure the pipe so that it does not move until the melted portion solidifies.

However, if a jig is used for fusion bonding, the return portion of the jig inserted into the pipe is caught on the inner peripheral surface of the pipe, and misalignment of the pipe can be suppressed. However, it becomes possible to move the piping, and it is possible to suppress the decrease in productivity. The joining of the pipes is completed when the molten thermoplastic resin is solidified.
In addition, since the return part of the jig arranged inside the pipe is caught on the inner peripheral surface of the pipe, the joint strength between the first pipe and the second pipe can be improved compared to the case of only fusion. It becomes possible.

According to a second aspect of the invention, in the jig according to the first aspect, a fusion layer made of a thermoplastic resin is provided on the outer peripheral portion of the main body portion.

In the jig according to claim 2, since the fusion layer made of thermoplastic resin is provided on the outer peripheral portion of the main body, the fusion layer is heated and melted in advance when the jig is inserted into the pipe. By doing so, the melted thermoplastic resin of the fusion layer can be brought into contact with the inner peripheral surface of the pipe after it is inserted into the pipe. After that, the thermoplastic resin of the fusion layer is cooled and solidified, so that the jig and the pipe are fused to complete the pipe joint.

A pipe fusion structure according to claim 3 is characterized in that a first pipe made of a thermoplastic resin, a second pipe made of a thermoplastic resin and fused with the first pipe, one end of which is connected to the first pipe and a jig according to claim 1 or 2, which is inserted into a pipe and whose other end is inserted into the second pipe.

In the pipe fused structure according to claim 3, the first pipe and the second pipe are connected with one end of the jig inserted into the first pipe and the other end of the jig inserted into the second pipe. are fused.

In the piping fused structure according to claim 3, since the return part of the jig is caught on the inner peripheral surface of the piping, the first piping and the second piping are fused and the thermoplastic resin is not solidified. However, it has a structure that allows the piping to be moved. In addition, since the return portion of the jig arranged inside the pipe is caught on the inner peripheral surface of the pipe, the joint strength between the first pipe and the second pipe can be improved compared to the case of only fusion bonding. can.

The method for fusing pipes according to claim 4 comprises: a melting step of melting the surface of the end portion of the first pipe made of thermoplastic material and the surface of the end portion of the second pipe made of thermoplastic material; Inserting one end side of the jig according to any one of claims 1 to 3 into the first pipe and inserting the other end side of the jig into the second pipe, a fusing step of contacting and fusing the end portion of the first pipe whose surface is melted and the end portion of the second pipe whose surface is melted.

In the pipe fusing method according to claim 4, the surface of the end portion of the first pipe made of thermoplastic material and the surface of the end portion of the second pipe made of thermoplastic material are melted in the melting step.
In the fusing step, one end side of the jig according to any one of claims 1 to 3 is inserted into the first pipe, and the other end side of the jig is inserted into the second pipe. Then, the end portion where the surface of the first pipe is melted and the end portion where the surface of the second pipe is melted are brought into contact and fused.
Since a jig is used for fusion bonding, the return portion of the jig inserted into the pipe is caught on the inner peripheral surface of the pipe, thereby suppressing displacement of the pipe. Therefore, even if the melted portion of the pipe is not solidified, the pipe can be moved, thereby suppressing a decrease in productivity.

According to a fifth aspect of the invention, there is provided the method for fusing pipes according to the fourth aspect, wherein the end portion of the first pipe is processed to have a small diameter portion, and the jig is inserted into the first pipe. The length of the portion where the small diameter portion is inserted is set to be equal to or longer than the length of the small diameter portion, and the end portion of the second pipe is processed with an enlarged diameter portion into which the small diameter portion is inserted, and in the melting step, , the outer peripheral surface of the small diameter portion of the first pipe is melted, the inner peripheral surface of the enlarged diameter portion of the second pipe is melted, and in the fusion step, the small diameter portion is inserted into the enlarged diameter portion. The fusing is performed.

In the pipe fused structure according to claim 5, the outer peripheral surface of the small diameter portion processed at the end portion of the first pipe is melted, and the inner peripheral surface of the enlarged diameter portion processed at the end portion of the second pipe is melted. Therefore, compared with the case where the end face of the pipe is melted, the fusion bonding area can be increased and the joint strength of the pipe can be improved.

Further, by processing the small diameter portion, the thickness of the small diameter portion becomes thinner than other portions where the small diameter portion is not processed, and the rigidity is lowered. Therefore, by setting the length of the portion of the jig to be inserted into the first pipe to be equal to or longer than the length of the small diameter portion, the entire thinned small diameter portion can be reinforced with the jig.

If the small diameter portion is inserted into the enlarged diameter portion without using a jig, the small diameter portion will be deformed by the resistance when inserting the small diameter portion into the enlarged diameter portion, and the cross-sectional shape of the pipe will not be a perfect circle. Also, defects such as swelling of the inner peripheral surface of the pipe may occur inside the pipe.
On the other hand, if the entire small-diameter portion is reinforced with a jig, it is possible to suppress deformation of the small-diameter portion when it is inserted into the enlarged-diameter portion.

As described above, according to the jig, pipe welding structure, and pipe welding method of the present invention, it is possible to improve productivity.

(A) is a cross-sectional view along the axis showing the jig according to the first embodiment of the present invention, and (B) is a cross-sectional view showing a pipe fusion structure in which resin pipes are welded using the jig. is. It is sectional drawing along the axis line which shows the 1st piping before welding using a jig|tool, and a 2nd piping. FIG. 6 is an axial cross-sectional view showing a jig according to a second embodiment of the present invention; FIG. 8 is a cross-sectional view showing a pipe fusion structure in which resin pipes are welded using a jig according to the second embodiment; FIG. 8 is a cross-sectional view along the axis showing a jig according to a third embodiment of the present invention; FIG. 11 is a cross-sectional view showing a pipe fusion structure in which a resin pipe is welded using a jig according to a third embodiment;

[First Embodiment]
A first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG.
FIG. 1B shows a cross-sectional view of a pipe fusion structure in which a first pipe 12 and a second pipe 14 made of thermoplastic resin are fused using the jig 10 of the present embodiment. .
As the thermoplastic resin used for the first pipe 12 and the second pipe 14, polybutene can be mentioned, but other thermoplastic resins may be used.

As shown in FIG. 2, the first pipe 12 before fusion has a small-diameter portion 16 formed on the distal end side, and the second pipe 14 has a small-diameter portion 16 on the distal end side of the first pipe 12 . It has an enlarged diameter portion 18 into which the portion 16 can be inserted.
The first pipe 12 has a uniform outer diameter and inner diameter as a whole. is also a portion formed to have a small diameter. The expanded diameter portion is, for example, a portion formed by processing the inner peripheral portion to have a larger diameter than the inner diameter of the constant diameter portion of the first pipe 12 .

The first pipe 12 and the second pipe 14 heat the surface of the outer peripheral surface 16A and the end surface 16B of the small diameter portion 16, the inner peripheral surface 18A of the enlarged diameter portion 18, and the surface of the deep stepped portion 18B of the enlarged diameter portion 18. After melting, the small-diameter portion 16 of the first pipe 12 is inserted into the enlarged-diameter portion 18 of the second pipe 14, and the melted resins are brought into contact with each other for fusion. The details of the fusion bonding method will be described later.

The length L0 of the small-diameter portion 16 of the first pipe 12 is not limited at times, but is set so that the first pipe 12 and the second pipe 14 do not separate due to external force, internal pressure, or the like, and cracks do not occur in the welded portions. ing.

(Configuration of Jig)
As shown in FIG. 1A, the jig 10 includes, as an example, a cylindrical body portion 10A made of a metal material such as stainless steel and having a constant diameter, and barbed portions 10B are provided at both ends. A stopper 10C is formed in the intermediate portion.

The body portion 10A is formed to have a constant diameter (outer diameter φD0) except for the return portions 10B at both ends and the stopper 10C.
The outer diameter (φD0) of the constant diameter portion of the body portion 10A of the present embodiment is set so that the outer peripheral surface is in close contact with the inner peripheral surface of the pipe when inserted into the first pipe 12 or the second pipe 14. ing.

As shown in FIGS. 1(A) and 1(B), the return portion 10B has a maximum diameter (φD3max) larger than the outer diameter (φD0) of the constant diameter portion, and the first pipe 12 and the second pipe 14 It is set larger than the inner diameter (φD4).
The return portion 10B is formed in a tapered shape (truncated cone shape) in which the diameter decreases toward the distal end side of the main body portion 10A. The outer diameter (φD5) of the minimum diameter portion on the tip side of the return portion 10B is set to the inner diameter (φD4) of the first pipe 12 and the second pipe 14 so that it can be easily inserted into the first pipe 12 and the second pipe 14. It is preferable to set the following.

As shown in FIGS. 1 and 2, the outer diameter (φD1) of the stopper 10C is larger than the outer diameter (φD0) of the constant diameter portion and the inner diameter of the enlarged diameter portion 18 of the second pipe 14. The diameter is set to be smaller than (φD6).

In the jig 10 of this embodiment, the length L1 of the portion 20 into which the first pipe 12 is inserted (between the tip and the side surface of the stopper 10C) and the length L2 of the portion 22 into which the second pipe 14 is inserted are are different, and the length L1 is formed longer than the length L2. Also, the length L1 of the portion 20 into which the first pipe 12 is inserted is formed longer than the length L0 of the small diameter portion 16 of the first pipe 12 .

(fusion of piping using a jig)
Below, a pipe fusion process using the jig 10 of the present embodiment will be described.
(1) Prepare the first pipe 12 with the small diameter portion 16 and the second pipe 14 with the enlarged diameter portion 18, and heat the outer peripheral surface 16A and the end surface 16B of the small diameter portion 16 to melt the surfaces. At the same time, the inner peripheral surface 18A of the enlarged diameter portion 18 and the stepped portion 18B are heated to melt the surfaces.

(2) Insert the portion 20 of the jig 10 having the length L1 into the first pipe 12 and insert the opposite portion 22 of the jig 10 into the second pipe 14 . The first pipe 12 and the second pipe 14 are inserted until their ends hit the stopper 10C.

As a result, the small diameter portion 16 of the first pipe 12 is inserted into the enlarged diameter portion 18 of the second pipe 14, and the molten thermoplastic resin of the first pipe 12 and the molten thermoplastic resin of the second pipe 14 come into contact with each other. , fusing is performed. In FIG. 1B, reference numeral 11 indicates a portion where the thermoplastic resin of the first pipe 12 and the thermoplastic resin of the second pipe 14 are fused together.

When the jig 10 is inserted into the pipe, the return portion 10B bites into and gets caught on the inner peripheral surface of the pipe. Even if a force acting in a direction to separate the first pipe 12 and the second pipe 14 from the jig 10 , the displacement of the first pipe 12 and the second pipe 14 is suppressed. Therefore, the displacement between the first pipe 12 and the second pipe 14 is suppressed, and the occurrence of poor fusion can be suppressed.

By using the jig 10 as described above, it is possible to transport the first pipe 12 and the second pipe 14 that have undergone the fusion process to the next process before the thermoplastic resin of the welded portion is solidified. , the need to cure the first pipe 12 and the second pipe 14 after the fusion bonding process is eliminated, and production efficiency can be improved.

[Second embodiment]
A jig 10 according to a second embodiment of the present invention will be described with reference to FIGS. 3 and 4. FIG. In addition, the same code|symbol is attached|subjected to the same structure as 1st Embodiment, and the description is abbreviate|omitted.

As shown in FIG. 3, in the jig 10 of the present embodiment, the same thermoplastic resin as the first pipe 12 and the second pipe 14 is formed on the outer periphery of the constant diameter portion between the return portion 10B and the stopper 10C. A fusing layer 32 is provided.

The fusion layer 32 is formed in a thin tubular shape, and for example, the end of the jig 10 is press-fitted into the tubular fusion layer 32, or a portion having a constant diameter is coated with a thermoplastic resin. It can be set by doing.

The small diameter portion 16 of the first pipe 12 used in this embodiment is not processed, and the enlarged diameter portion 18 of the second pipe 14 is not processed.
Also, in the jig 10 of the present embodiment, the lengths L1 and L2 on both sides of the stopper 10C are set to be the same length.

(fusion of piping using a jig)
Below, a pipe fusion process using the jig 10 of the present embodiment will be described.
(1) The first pipe 12 and the second pipe 14 are prepared, and the jig 10 in which the fusion layer 32 is heated and melted is inserted into the first pipe 12 and the second pipe 14 .

(2) As shown in FIG. 4, when the jig 10 is inserted into the first pipe 12 and the second pipe 14, the melted fusion layer 32 is applied to the seed surface of the main body portion 10A of the jig 10. and fused to the inner peripheral surfaces of the first pipe 12 and the second pipe 14 .

(3) After inserting the jig 10 into the first pipe 12 and the second pipe 14, the gap formed on the outer peripheral side of the stopper 10C of the jig 10 is filled with the molten thermoplastic resin 33, and the molten thermoplastic resin 33 is filled. The joining of the first pipe 12 and the second pipe 14 is completed by solidifying the layer 32 and the thermoplastic resin 33 .

In this embodiment as well, the return portion 10B of the jig 10 bites into and is caught in the inner peripheral surface of the pipe. Even if a force in a separating direction acts, the jig 10 is prevented from being detached from the first pipe 12 and the second pipe 14, and the production efficiency can be improved as in the first embodiment.

[Third embodiment]
A jig 10 according to a third embodiment of the present invention will be described with reference to FIGS. 5 and 6. FIG. Note that the jig 10 of the present embodiment is a modified example of the jig 10 of the second embodiment, and the same components as those of the second embodiment are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 5, in the jig 10 of the present embodiment, a magnetic heating layer 34 containing a magnetic material is laminated on the outer peripheral side of the fusion layer 32 .

(fusion of piping using a jig)
Below, a pipe fusion process using the jig 10 of the present embodiment will be described.
(1) Insert one side of the jig 10 into the first pipe 12 and insert the other side of the jig 10 into the second pipe 14 .
By inserting the jig 10, the return portion 10B is caught on the inner peripheral surface of the pipe, and the jig 10 is prevented from coming off from the first pipe 12 and the second pipe 14, as in the above-described embodiment.

(2) As shown in FIG. 6, a coil 36 is arranged on the outer peripheral side of the part into which the jig 10 is inserted. As the fusion layer 32 melts, the inner peripheral surface of the first pipe 12 and the inner peripheral surface of the second pipe 14 melt.
When the molten thermoplastic resin is cooled and solidified, the first pipe 12 and the jig 10 are fixed together, and the second pipe 14 and the jig 10 are fixed together, so that the first pipe 12 and the second pipe 14 are joined together. complete.

In the jig 10 of the third embodiment, the magnetic heat generating layer 34 is laminated on the outer peripheral surface of the fusion layer 32, but the magnetic heat generating layer 34 is not limited to the outer peripheral surface of the fusion layer 32. It may be embedded inside, or may be provided on the inner peripheral surface of the fusion layer 32 .

The magnetic heat generating layer 34 may be a mixture of a magnetic powder and a thermoplastic resin, or may be a magnetic metal material itself. good. Alternatively, magnetic powder may be mixed with the thermoplastic resin of the fusion layer 32, in which case the magnetic heating layer 34 is not required.

[Other embodiments]
An embodiment of the present invention has been described above, but the present invention is not limited to the above, and can of course be implemented in various modifications without departing from the gist of the present invention. is.

Although the jig 10 of this embodiment is made of a metal material, it may be made of a material other than a metal material. Examples of materials other than metal materials include resin materials such as fiber-reinforced plastics. When the jig 10 is made of a resin material, the resin material may be a resin material having a higher heat resistance temperature than the thermoplastic resin used for the first pipe 12 and the second pipe 14, or a thermosetting resin. can be done.

Further, if the jig 10 is made of a magnetic material (metal) that generates heat by receiving magnetic lines of force, the magnetic heating layer 34 can be omitted.

DESCRIPTION OF SYMBOLS 10... Jig, 10A... Main-body part, 10B... Return part, 12... 1st piping (resin piping), 14... 2nd piping (resin piping), 16... Small diameter part, 18... Expanding diameter part, 32... Fusion|fusion layer

Claims (5)

A jig used for fusing together resin pipes made of thermoplastic resin,
a cylindrical main body inserted into the resin pipe;
Tapered return portions provided at both ends in the longitudinal direction of the main body portion, having a maximum diameter larger than the outer diameter of the main body portion, and having a diameter that decreases toward the tip side of the main body portion;
Jig with A fusion layer made of a thermoplastic resin is provided on the outer periphery of the main body,
The jig according to claim 1. a first pipe made of a thermoplastic resin;
a second pipe made of a thermoplastic resin and fused to the first pipe;
3. The jig according to claim 1 or 2, one end of which is inserted into the first pipe and the other end of which is inserted into the second pipe;
Piping fused structure. a melting step of melting the surface of the end portion of the first pipe made of thermoplastic material and the surface of the end portion of the second pipe made of thermoplastic material;
One end side of the jig according to claim 1 is inserted into the first pipe and the other end side of the jig is inserted into the second pipe so that the surface of the first pipe is a fusing step of bringing the melted end portion and the end portion of the second pipe melted into contact with each other and fusing;
A piping fusion method. A small diameter portion is processed at the end portion of the first pipe,
a length of a portion of the jig to be inserted into the first pipe is set to be equal to or longer than the length of the small diameter portion;
An end portion of the second pipe is processed with an enlarged diameter portion into which the small diameter portion is inserted,
In the melting step, the outer peripheral surface of the small diameter portion of the first pipe is melted, the inner peripheral surface of the enlarged diameter portion of the second pipe is melted,
In the fusion bonding step, the fusion bonding is performed by inserting the small diameter portion into the enlarged diameter portion.
The piping fusion method according to claim 4.

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