JP2022034892A - Fusion method and electric fusion joint - Google Patents

Abstract

To provide an electric fusion joint that can suppress formation of a gap and uneven resin swelling.SOLUTION: A fusion method for fusing an electric fusion joint 1 to resin pipes 11, 12 includes a step S1, a step S3 and a step S4. In the step S1, the resin pipes 11, 12 are inserted into joint sockets 23, 24 of the electric fusion joint 1. In the step S3, energization of a stopper heating unit 4 is started. In the step S4, energization of a socket heating unit 3 is started after the start of energization to the stopper heating unit 4.SELECTED DRAWING: Figure 2

Description

The present invention relates to a fusion method and an electrically fusion joint.

When connecting pipes using a resin such as a resin pipe or a metal reinforced composite pipe having a resin layer and a metal reinforcing layer, an electric fusion joint is often used (see, for example, Patent Document 1).

For example, in the electric fusion joint shown in Patent Document 1, a joint body made of a thermoplastic resin in which a pipe receiving port into which a pipe to be connected is inserted is formed at each end, and an inner side inside the inner peripheral surface of the joint body. A stopper portion protruding toward is provided. The stopper portion regulates the position of the pipe inserted into the pipe receiving port. A heating element is provided in each of the pipe receiving port and the stopper portion, and by generating heat of the heating element, the resin around the heating element and the resin of the pipe are fused, and the electric fusion joint and the pipe are connected. ..

Japanese Unexamined Patent Publication No. 5-87286

However, it is difficult to control the fusion because the fusion is performed at two points, the stopper and the pipe receiving port, and the height of the resin fused and raised inward between the stopper and the end of the pipe is in the circumferential direction. In some cases, it may become non-uniform, or a gap (clevis) may be formed between the stopper portion and the end of the pipe.

Turbulent flow occurs when non-uniform resin swelling or clevis is formed, so that some water or chemicals tend to stay in the pipe. As a result, microorganisms may propagate and cause deterioration of water quality, or deterioration of the chemical solution may cause deterioration of purity, which may cause deterioration of product yield in semiconductor manufacturing pipes and the like.

An object of the present invention is to provide a fusion method and an electric fusion joint capable of suppressing the formation of gaps and uneven swelling of a resin.

In order to achieve the above object, the fusion method according to the first aspect is to melt an electric fusion joint and a pipe provided with a cylindrical portion, a stopper portion, a receiving port heat generating portion, and a stopper heating portion. It is a fusion method for fusing, and includes an insertion step, a first energization step, and a second energization step. The tubular portion has a joint receiving portion into which a tube containing a thermoplastic resin can be inserted inside. The stopper portion is provided so as to project inward on the inner surface of the tubular portion, and when the pipe is inserted inside the joint receiving portion, the insertion position of the pipe end of the pipe can be regulated. The receiving port heating portion includes a heating wire arranged in the joint receiving portion. The stopper heating unit includes a heating wire arranged in the stopper unit. In the insertion step, the pipe is inserted inside the joint receiving portion of the electric fusion joint. In the first energization step, energization is started in the stopper heat generating portion. In the second energization step, the energization of the receiving port heating unit is started after the energization of the stopper heating unit is started.

By energizing the stopper heat generating portion, the end of the pipe and the stopper portion are fused, and by energizing the receiving port heating portion, the outer peripheral surface of the pipe and the inner peripheral surface of the joint receiving portion are fused. The clearance formed between the pipe and the electrically fused joint (including the clearance between the end of the pipe and the stopper and the clearance between the outer peripheral surface of the pipe and the inner peripheral surface of the joint socket) is non-uniform. Because of the wide range, the molten resin will flow into a place where it can easily flow. For example, when the resin melted on the outer peripheral surface of the pipe and the inner peripheral surface of the joint receiving portion flows unevenly to the side between the end of the pipe and the stopper portion, the resin fused between the stopper portion and the end of the pipe. The inward swelling becomes non-uniform in the circumferential direction, and in some cases, a gap may be formed in the swelling.

On the other hand, in the first aspect, by energizing the stopper heat generating portion before the socket heating portion, the resin melted between the inner peripheral surface of the joint receiving portion and the outer peripheral surface of the pipe becomes the stopper portion. The space between the stopper and the end of the pipe can be filled with melted or hardened resin so that it does not flow unevenly between the end of the pipe and the end of the pipe. Therefore, it is possible to suppress non-uniformity of the swelling of the resin in the circumferential direction. Further, since the portions of the stopper portion and the end of the pipe facing each other are in a narrow range, the amount of the resin to be melted is small, the amount of the resin rising inward can be reduced, and the pressure loss can be suppressed. It is preferable that the above-mentioned melted resin is hardened to the extent that the inflow of the resin can be prevented. Further, since the non-uniformity of the swelling can be suppressed, the dent of the resin does not occur, and the end of the pipe can be prevented from coming into contact with the fluid.

The fusion method according to the second aspect is a fusion method for fusing an electric fusion joint provided with a tubular portion, a stopper portion, a receiving port heat generating portion, and a stopper heating portion, and a pipe. , An insertion step, a first energization step, and a second energization step. The tubular portion is tubular and has a joint receiving portion into which a tube containing a thermoplastic resin can be inserted inside. The stopper portion is provided so as to project inward on the inner surface of the tubular portion, and when the pipe is inserted inside the joint receiving portion, the insertion position of the pipe end of the pipe can be regulated. The receiving port heating portion includes a heating wire arranged in the joint receiving portion. The stopper heating unit includes a heating wire arranged in the stopper unit. In the insertion step, the pipe is inserted inside the joint receiving portion of the electric fusion joint. In the first energization step, energization is started in the receiving port heat generating portion. In the second energization step, energization of the stopper heat generating portion is started after the energization of the receiving port heating portion is started.

For example, when the resin melted between the end of the pipe and the stopper flows into the clearance between the inner surface of the joint receiving portion and the outer peripheral surface of the pipe, the resin fused between the stopper and the end of the pipe. The swelling of the swelling becomes non-uniform in the circumferential direction, and in some cases, a gap may be formed in the swelling.

On the other hand, in the second aspect, in order to fill a wide clearance between the inner peripheral surface of the joint receiving portion and the outer peripheral surface of the pipe with the melted or hardened resin, it melts between the stopper portion and the end of the pipe. It is possible to prevent the resin from flowing between the inner peripheral surface of the joint receiving portion and the outer peripheral surface of the pipe. Therefore, it is possible to suppress non-uniformity of the swelling of the resin in the circumferential direction. Also, the end of the tube can be prevented from coming into contact with the fluid. Further, since the non-uniformity of the swelling can be suppressed, the dent of the resin does not occur, and the end of the pipe can be prevented from coming into contact with the fluid. It is preferable that the above-mentioned melted resin is hardened to the extent that the inflow of the resin can be prevented.

The electric fusion joint according to the third aspect includes a cylindrical portion, a stopper portion, a receiving port heating portion, a stopper heating portion, a pair of first terminals, and a pair of second terminals. The tubular portion is tubular and has a joint receiving portion into which a tube containing a thermoplastic resin can be inserted inside. The stopper portion is provided so as to project inward on the inner surface of the tubular portion, and when the pipe is inserted inside the joint receiving portion, the insertion position of the pipe end of the pipe can be regulated. The receiving port heating portion includes a heating wire arranged in the joint receiving portion. The stopper heating unit includes a heating wire arranged in the stopper unit. The pair of first terminals are connected to the heating wire of the receiving port heating unit in order to energize the receiving port heating unit. The pair of second terminals are connected to the heating wire of the stopper heating portion in order to energize the stopper heating portion.

In this way, the heating wire of the stopper heating part and the heating wire of the receiving port heating part are not connected, and they have a pair of terminals for energizing separately. The timing of energizing the heat generating part of the mouth can be shifted.

Therefore, fusion by the stopper heating part and fusion by the receiving port heating part can be controlled individually, and depending on the material and size of the electric fusion joint and the pipe, the energization timing to the stopper heating part and the receiving port heat generation can be controlled. By advancing the timing of either one of the energization timings to the portions, it is possible to suppress the formation of gaps and the uneven swelling of the resin.

According to the present disclosure, it is possible to provide an electrically fused joint capable of suppressing the formation of gaps and uneven swelling of a resin, and a fusion method.

The external view which shows the electric fusion joint and the resin pipe connected to the electric fusion joint in Embodiment 1 which concerns on this disclosure. The cross-sectional block diagram which shows the electric fusion joint of FIG. FIG. 3 is a cross-sectional configuration diagram showing a state in which a resin pipe and a resin pipe are inserted into the electrically fused joint of FIG. FIG. 3 is a schematic view of an electric fusion joint showing a connection relationship between a heat receiving portion and a stopper heating portion of FIG. 3 and a first connector mounting portion and a second connector mounting portion. The schematic diagram which shows the state which the electric fusion joint is energized by the electric fusion apparatus. The flow diagram for demonstrating the fusion method using the electric fusion joint of FIG. FIG. 6 is a perspective view showing a pressure jig used in the fusion method of FIG. The figure which shows the state which attached the resin tube, the electric fusion joint, and the resin tube to the pressure jig of FIG. (A) A schematic diagram showing a state in which the resin is unevenly raised, and (b) a schematic diagram showing a state in which the resin is uniformly raised. The cross-sectional view which shows the state which the stopper part of an electric fusion joint and the pipe end of a resin pipe are fused by the heat generation of a stopper heat generation part. The flow diagram for demonstrating the fusion method in the modification of the embodiment of this disclosure.

Hereinafter, embodiments according to the invention will be described with reference to the drawings.

<Structure>
(Outline of electric fusion joint 1)
FIG. 1 shows an electric fusion joint 1 according to an embodiment of the present invention, a resin pipe 11 (an example of a pipe containing a thermoplastic resin) connected by the electric fusion joint 1, and a resin pipe 12 (a thermoplastic resin). It is a figure which shows an example of a tube including). FIG. 1 can be said to be an exploded view of the piping structure 100. The piping structure 100 includes, for example, an electric fusion joint 1, a resin pipe 11, and a resin pipe 12.

As shown in the figure, the electric fusion joint 1 is fused with the resin pipe 11 and the resin pipe 12, and connects the resin pipe 11 and the resin pipe 12.

The resin tube 11 and the resin tube 12 are each made of a thermoplastic resin.

In the resin pipe 11 and the resin pipe 12, flow paths 11f and 12f having a circular cross section extend inside. A flow path 1f having a circular cross section extends inside the electrically fused joint 1. In a state where the resin pipe 11 and the resin pipe 12 are connected by the electric fusion joint 1, the axes of the respective flow paths of the resin pipe 11, the resin pipe 12, and the electric fusion joint 1 are arranged on the same straight line.

The direction in which each axis extends with respect to the flow paths of the electrically fused joint 1, the resin pipe 11, and the resin pipe 12 is defined as the axis direction A. Further, in the electrically fused joint 1, the resin pipe 11, and the resin pipe 12, the direction in which the electric fusion joint 1, the resin pipe 11, and the resin pipe 12 are orthogonal to each other and are close to each other and separated from each other is defined as the radial direction B, and the direction around each axis is defined as the circumferential direction C.

The resin pipe 11 moves relative to the electric fusion joint 1 in the axial direction A in the direction of the arrow A1 and is connected to the electric fusion joint 1. Further, the resin pipe 12 moves relative to the electric fusion joint 1 in the axial direction A in the direction of the arrow A2 and is connected to the electric fusion joint 1. The state in which the resin pipe 11 and the resin pipe 12 are connected to the electric fusion joint 1 constitutes the piping structure 100.

FIG. 2 is a diagram showing a cross-sectional configuration of the electric fusion joint 1.

As shown in FIGS. 1 and 2, the electric fusion joint 1 includes a main body portion 2, a receiving port heating portion 3, a stopper heating portion 4, a first connector mounting portion 5, and a second connector mounting portion 6. , Have.

(Main body 2)
The main body portion 2 is made of a thermoplastic resin, and has a tubular portion 21 and a stopper portion 22 as shown in FIG. The tubular portion 21 is tubular and has a joint receiving portion 23, a joint receiving portion 24, and a continuous portion 25. A resin pipe 11 is inserted inside the joint receiving portion 23. A resin pipe 12 is inserted inside the joint receiving portion 24.

The thermoplastic resin used in the main body 2 is not particularly limited, but a thermoplastic resin having a melting point of less than 230 ° C. is preferable.

FIG. 3 is a cross-sectional configuration diagram showing a state in which the resin pipe 11 is inserted inside the joint receiving portion 23 of the electric fusion joint 1 and the resin pipe 12 is inserted inside the joint receiving portion 24.

The inner diameter of the joint receiving portion 23 is formed to be larger than the outer diameter of the resin pipe 11. Further, the inner diameter of the joint receiving portion 24 is formed to be larger than the outer diameter of the resin pipe 12.

As shown in FIG. 2, the continuous portion 25 is connected to the joint receiving portion 23 and the joint receiving portion 24, and connects the joint receiving portion 23 and the joint receiving portion 24. The continuous portion 25 is a portion that connects between the joint receiving portion 23 and the joint receiving portion 24, and a stopper portion 22, which will be described later, is provided inside the radial direction B.

(Stopper portion 22)
The stopper portion 22 is an annular portion. The stopper portion 22 is a ridge on the inner surface 21a of the tubular portion 21 along the circumferential direction C, and is formed over the entire circumference. The stopper portion 22 also contains a thermoplastic resin, and is preferably formed of the same resin as the thermoplastic resin used in the tubular portion 21.

As shown in FIG. 2, the stopper portion 22 is formed so as to project inward in the radial direction from the inner surface 21a of the tubular portion 21. Further, the stopper portion 22 is arranged inside the continuous portion 25 of the tubular portion 21 in the radial direction B. The stopper portion 22 may be formed as one member with the tubular portion 21 or may be formed as a separate member from the tubular portion 21.

The stopper portion 22 has a first side surface 22a, a second side surface 22b, and a peripheral surface 22c. The peripheral surface 22c is an end surface on the inner side in the radial direction of the stopper portion 22.

The first side surface 22a is formed substantially perpendicular to the axial direction A from the inner surface 21a of the tubular portion 21 toward the inside of the radial direction B.

The second side surface 22b is formed substantially perpendicular to the axial direction A from the inner surface 21a of the tubular portion 21 toward the inside of the radial direction B.

The peripheral surface 22c connects the radial inner end of the first side surface 22a and the radial inner end of the second side surface 22b. The peripheral surface 22c is formed substantially parallel to the inner surface 21a of the tubular portion 21.

When the resin pipe 11 is inserted inside the joint receiving portion 23, the stopper portion 22 regulates the insertion position of the pipe end 11a as shown in FIG. The insertion position of the pipe end 11a is regulated when the pipe end 11a comes into contact with the first side surface 22a of the stopper portion 22 and the stopper portion 22 is directly regulated as shown in FIG. 3, and the pipe end 11a is a stopper. This includes the case where the stopper portion 22 indirectly regulates by contacting the heating wire 41 (described later) of the heat generating portion 4.

When the resin pipe 12 is inserted inside the joint receiving portion 24, the stopper portion 22 regulates the insertion position of the pipe end 12a as shown in FIG. The insertion position of the pipe end 12a is regulated when the pipe end 12a comes into contact with the second side surface 22b of the stopper portion 22 and the stopper portion 22 directly regulates the insertion position, and when the pipe end 12a is a stopper. This includes the case where the stopper portion 22 indirectly regulates by contacting the heating wire 41 (described later) of the heat generating portion 4.

In this embodiment, the generation of clevis is suppressed between the pipe end 11a and the first side surface 22a and between the pipe end 12a and the second side surface 22b (see position P).

(Receptacle heating unit 3)
FIG. 4 is a schematic view of an electric fusion joint 1 showing a connection relationship between a receiving port heating unit 3 and a stopper heating unit 4 and a first connector mounting portion 5 and a second connector mounting portion 6. In FIG. 4, in order to facilitate understanding, the configuration of winding the heating wire 31 in the receiving port heating unit 3 is simplified.

As shown in FIGS. 2 and 4, the receiving port heat generating portion 3 is provided in the joint receiving portion 23 and the joint receiving portion 24.

The receiving port heating unit 3 has a heating wire 31 embedded in the inner surface 21a of the joint receiving portion 23 and the joint receiving portion 24.

The heating wire 31 is arranged so as to be wound in the circumferential direction along the inner surface 21a in the joint receiving portion 23 and the joint receiving portion 24. The heating wire 31 is arranged in the vicinity of the inner surface 21a. The heating wire 31 may be partially embedded in the cylindrical portion 21 so as to be partially exposed on the flow path 1f side, or may be completely embedded.

For the sake of clarity, the portion of the heating wire 31 arranged at the joint receiving portion 23 is referred to as the heating wire portion 31a, and the portion of the heating wire 31 arranged at the joint receiving portion 24 is referred to as the heating wire portion 31b. And.

Of the heating wires 31, the heating wire portion 31c connecting the heating wire portion 31a and the heating wire portion 31b is embedded in the continuous portion 25.

The heating wire portion 31c is located on the outer peripheral side of the stopper heating portion 4. The heating wire portion 31c is arranged so as not to come into contact with the heating wire 41 provided in the stopper heating unit 4.

A single heating wire 31 is arranged over the joint receiving portion 23, the joint receiving portion 24, and the continuous portion 25, but the heating wire portion 31a, the heating wire portion 31b, and the heating wire portion 31c are arranged. Each may be composed of separate heating wires, to which the heating wires may be connected.

The heating wire 31 may have, for example, a conducting wire and an insulating film. As the conducting wire, for example, a nichrome wire, an iron chromium type 2 wire, an iron chromium type 1 wire, a nickel chromium wire, or the like can be used. The insulating film is provided so as to cover the periphery of the conducting wire. The insulating film has a melting point of 230 degrees or higher. It is preferable that this is set to a temperature at which the thermoplastic resin does not melt even at a temperature at which the thermoplastic resin melts (for example, in the case of polyethylene, the heating wire is heated to 220 degrees) in the present embodiment. The insulating film can be formed of, for example, a fluorine-based resin or an imide-based resin, but it is more preferable to form the insulating film with a polyimide-based resin. For example, the thickness of the conductor may be set to 0.1 mm or more and 10 mm or less. Further, the heating wire 31 generates heat at about 180 to 230 degrees.

The arrangement of the heating wire 31 in the receiving port heating unit 3 will be described. Since the heat receiving portion 3 is provided symmetrically with respect to the stopper portion 22, the heating wire 31 arranged in the joint receiving portion 23 will be described.

The heating wire portion 31a is arranged so that the heating wire density in the joint receiving portion 23 is smaller than the heating wire density in the stopper heating portion 4 described later.

In the joint receiving portion 23, the heating wire 31 is repeatedly wound twice so as to be in contact with the heating wire 31, and is repeatedly wound twice so as to be in contact with the heating wire 31 at a predetermined interval along the axial direction A. In the present embodiment, as shown in FIG. 2, for example, the heating wire 31 is wound around eight times.

Further, in FIG. 2, assuming that the length of the region where the heating wire 31 is arranged along the axial direction A is L, in the present embodiment, eight heating wires 31 are arranged in the length L. It will be different. The length L can be said to be the length of the receiving port heating unit 3 along the axial direction A or the length of the heating wire 31 along the axial direction A.

Here, assuming that the outer diameter of the heating wire 31 is 1 mm and the predetermined interval is 5 mm, since there are eight heating wires at L = 23 mm, the heating wire density in the receiving heat generating portion 3 is 8 (lines). / 23 (mm) ≈ 0.35 (lines / mm).

In this way, the heating wire density is defined as the number of heating wires per unit length (for example, 1 mm). The heating wire density can be obtained as a value obtained by dividing the number of the heating wires 31 arranged at the length L along the axial direction A of the region where the heating wires 31 are arranged by the length L.

The clearance W1 (see FIG. 3) between the inner peripheral surface of the joint receiving portion 23 and the outer peripheral surface of the resin pipe 11 and the inner peripheral surface of the joint receiving portion 24 are used to generate heat in the receiving port heat generating portion 3. The clearance W1 between the outer peripheral surface of the resin pipe 12 is filled with the molten resin, and the joint receiving portion 23 and the resin pipe 11, and the joint receiving portion 242 and the resin pipe 12 are fused.

(1st connector mounting part 5)
As shown in FIG. 2, the first connector mounting portion 5 has two pins 51b and 51c (an example of a pair of first terminals). The two pins 51b and 51c are provided so as to project outward in the radial direction from the outer surface 21d of the tubular portion 21. As shown in FIG. 2, one of the two pins 51b and 51c is arranged in the vicinity of the end 21b of the tubular portion 21, and the other pin 51c is arranged in the vicinity of the end 21c.

As shown in FIG. 4, one end of the heating wire 31 of the receiving port heating portion 3 on the joint receiving portion 23 side is connected to the pin 51b. The end of the heating wire 31 of the receiving port heating portion 3 on the joint receiving portion 24 side is connected to the pin 51c. By attaching the first connector 81 of the electric fusion device 8 to the pin 51b and the pin 51c and energizing the pin 51b, the heat receiving portion 3 can be heated.

The energization time to the receiving port heating unit 3 may be set to 1 minute when the nominal diameter is 50 mm, and may be set to 10 minutes when the nominal diameter is 300 mm.

(Stopper heating unit 4)
The stopper heat generating portion 4 is provided on the stopper portion 22. The stopper heating unit 4 has a heating wire 41. The heating wire 41 is provided on the stopper portion 22 so as to be wound in the circumferential direction C along the axial direction A. In the present embodiment, the heating wire 41 is wound around the stopper portion 22, for example, three times. In the stopper heating unit 4 of the present embodiment, all the adjacent heating wires 41 are in contact with each other.

As the heating wire 41, those having the same material and composition as the heating wire 31 can be used. The heating wire 41 generates heat at about 180 to 230 degrees.

In the stopper heating unit 4, the heating wire 41 is wound around three times so as to come into contact with the heating wire 41. Therefore, three heating wires 41 are arranged in the length L (which can be said to be the length of the stopper heating unit 4) along the axial direction A in the region where the heating wires 41 are arranged.

The diameter of the wound heating wire 41 in the stopper heating unit 4 is set to be smaller than the diameter of the wound heating wire 31 in the receiving port heating unit 3.

Further, the diameter of the wound heating wire 41 in the stopper heating unit 4 is set so as to be within the tube wall thickness of the resin tubes 11 and 12 into which the position of the heating wire 41 is inserted.

As described above, assuming that the diameter of the heating wire is 1 mm, the heating wire density in the stopper heating unit 4 is set to 3 (lines) / 3 (mm) = 1 (lines / mm).

As described above, since the heating ray density in the receiving port heating unit 3 is about 0.35, in the present embodiment, the heating ray density in the receiving port heating unit 3 is smaller than the heating ray density in the stopper heating unit 4. It is set.

The arrangement of the heating wire 41 in the stopper heating unit 4 is not limited to the configuration of the present embodiment, and the heating wire 41 may not be in contact with the heating wire 41. Further, it is not necessary that three heating wires 41 are arranged along the axial direction A, one in the middle is not provided, and that portion is filled with the resin forming the stopper portion 22. May be good.

The heating wire density in the above-mentioned receiving port heating unit 3 is not limited to the configuration shown in FIG. 2, and in the present embodiment, the heating wire 31 is wound so that two rounds are in contact with each other. , It does not have to be limited to this. For example, the heating wire 31 may be wound so that three laps are in contact with each other, or the heating wire 31 may be wound so as to be in contact with each other at intervals of one lap.

The clearance W2 (see FIG. 3) between the first side surface 22a of the stopper portion 22 and the pipe end 11a of the resin pipe 11 and the second side surface 22b of the stopper portion 22 and the resin pipe are used to generate heat in the stopper heat generating portion 4. The clearance W2 between the pipe end 12a of the 12 is filled with the molten resin, and the stopper portion 22 and the resin pipe 11, and the stopper portion 22 and the resin pipe 12 are fused.

(2nd connector mounting part 6)
As shown in FIG. 2, the second connector mounting portion 6 has two pins 61b and 61c (an example of a pair of second terminals). The two pins 61b and 61c are provided so as to project radially outward from the outer surface 21d of the tubular portion 21. The two pins 61b and 61c are arranged side by side along the axial direction A near the center of the tubular portion 21.

One of the two pins 61b and 61c is arranged on the end 21b side, and the other pin 61c is arranged on the end 21c side.

As shown in FIG. 4, one end of the heating wire 41 is connected to the pin 61b, and the other end of the heating wire 41 is connected to the pin 61c. By attaching the connector of the electric fusion device to the pin 61b and the pin 61c and energizing the pin 61b, the heat receiving portion 3 can be heated.

The energizing time to the stopper heating unit 4 is about one-fifth of the energizing time to the receiving port heating unit 3. For example, when the nominal diameter is 50 mm, it is set to 20 seconds, and when the nominal diameter is 300 mm, 2 It may be set to minutes.

As described above, since the first connector mounting portion 5 for generating heat of the receiving port heat generating portion 3 and the second connector mounting portion 6 for generating heat of the stopper heating portion 4 are separately provided, the receiving port is provided. The energization timing to the heat generating portion 3 and the energizing timing to the stopper heating portion 4 can be staggered. That is, it is possible to start energizing the stopper heating unit 4 after starting energization to the socket heating unit 3, or to start energizing the stopper heating unit 4 after starting the energization of the receiving port heating unit 3.

(Electrical fusion device 8)
Next, the electric fusion apparatus 8 that energizes the electric fusion joint 1 will be described. FIG. 5 is a schematic view showing a state in which the electric fusion joint 1 is energized by the electric fusion apparatus 8.

The electric fusion device 8 has, for example, a pair of first connectors 81 attached to the pins 51b and 51c and a pair of second connectors 82 attached to the pins 61b and 61c.

The electric fusion apparatus 8 may be provided with, for example, a first energization switch that energizes the pair of first connectors 81 and a second energization switch that energizes the pair of second connectors 82. In this case, after operating the second energizing switch to start energizing the stopper heating unit 4, the first energizing switch can be operated to start energizing the receiving port heating unit 3. Further, after operating the first energization switch to start energizing the receiving port heating unit 3, the second energizing switch may be operated to start energizing the stopper heating unit 4.

The time from the start of energization to the heat generating portion of one of the stopper heat generating portion 4 and the receiving port heating portion 3 to the start of energizing the other heat generating portion is the clearance on the side where one of the heat generating portions is provided. Is preferably filled with resin. It should be noted that the term “filled with resin” may be filled with melted resin or may not be limited to filled with solidified resin. Further, although it depends on the performance, the coil and the nominal diameter of the electric fusion joint 1, the energization to the other heat generating portion may be started about 10 to 20 seconds after the start of energization to the one heat generating portion. Further, after the resin has hardened on one heat generating portion side, energization to the other heat generating portion may be started.

Further, the electric fusion device 8 may automatically energize the first connector 81 and the second connector 82 based on a preset program. When the control is started, energization to one of the heat generating portions of the stopper heating unit 4 and the receiving port heating portion 3 is started, and after a preset time, the other heating unit is energized. It will be started. Then, the electric fusion device 8 stops energization when a preset energization time for each heat generating portion elapses.

In this case, the electric fusion device 8 includes a processor and a storage device. The processor is, for example, a CPU (Central Processing Unit). Alternatively, the processor may be a processor different from the CPU. The processor executes a process for controlling energization according to a program. The storage device includes a non-volatile memory such as ROM (Read Only Memory) and a volatile memory such as RAM (Random Access Memory). The storage device may include a hard disk or an auxiliary storage device such as an SSD (Solid State Drive). A storage device is an example of a recording medium that can be read by a non-transitory computer. The storage device stores programs and data for controlling the electric fusion device 8. The storage device stores, for example, data of a terminal range described later and a predetermined threshold value of the operation speed.

<Fusion method>
Next, the fusion method of the embodiment according to the present invention will be described. Note that FIG. 6 is a flow chart for explaining the fusion method of the present embodiment.

In the present embodiment, a case where the energization of the receiving port heating unit 3 is started after the energization of the stopper heating unit 4 is started will be described.

First, in step S1, the resin pipe 11 is inserted inside the joint receiving portion 23 of the electrically fused joint 1 until the stopper portion 22 restricts the relative movement of the pipe end 11a of the resin pipe 11.

Further, the resin pipe 12 is inserted inside the joint receiving portion 24 of the electric fusion joint 1 until the stopper portion 22 restricts the relative movement of the pipe end 12a of the resin pipe 12. FIG. 3 shows a state in which the resin pipe 11 and the resin pipe 12 are inserted into the electric fusion joint 1. Step S1 corresponds to an example of the insertion step.

Next, in step S2, the resin pipe 11 is pressed in the direction of the stopper portion 22 (direction of arrow A1 shown in FIG. 8) so as to press the pipe end 11a against the first side surface 22a of the stopper portion 22. Further, the resin pipe 12 is pressurized in the direction of the stopper portion 22 (direction of arrow A2 shown in FIG. 8) so as to press the pipe end 12a against the second side surface 22b of the stopper portion 22.

Here, the pressure jig used for pressurization will be described. FIG. 7 is a diagram showing a pressure jig 200. FIG. 8 is a diagram showing a state in which the resin pipe 11, the electric fusion joint 1, and the resin pipe 12 are attached to the pressure jig 200.

The pressure jig 200 has a first clamp portion 210, a second clamp portion 220, three guide members 230, and a pressure screw member 240.

The first clamp portion 210 has a first semi-annular portion 211, a second semi-annular portion 212, a hinge portion 213, a fastening portion 214, and a position fixing portion 215.

The first semi-annular portion 211 and the second semi-annular portion 212 have substantially half the shape of an annulus, and can sandwich the outer periphery of the resin tube 11. The first semi-annular portion 211 has a guide support portion 211b and a screw portion 211c in the circumferential direction. A through hole is formed in the guide support portion 211b, and a rod-shaped guide member 230 is inserted therethrough.

The second semi-annular portion 212 has two guide support portions 212b and 212c in the circumferential direction. A through hole is formed in each of the guide support portion 212b and the guide support portion 212c, and a rod-shaped guide member 230 is inserted therethrough.

The hinge portion 213 rotatably connects the peripheral ends of the first semi-annular portion 211 and the second semi-annular portion 212. The resin tube 11 is arranged between the first semi-annular portion 211 and the second semi-annular portion 212 with the first semi-annular portion 211 and the second semi-annular portion 212 open around the hinge portion 213. To.

The fastening portion 214 is, for example, a screw and is provided at the end in the circumferential direction opposite to the hinge portion 213 of the first semi-annular portion 211 and the second semi-annular portion 212. The circumferential end of the first semi-annular portion 211 opposite to the hinge portion 213 protrudes outward, and a through hole is formed in the protruding portion 211a. Further, the circumferential end of the second semi-annular portion 212 on the opposite side to the hinge portion 213 projects outward, and a through hole is formed in the protruding portion 212a.

In a state where the first semi-annular portion 211 and the second semi-annular portion 212 are closed, the two through holes face each other, and the fastening portion 214 which is a screw is inserted. A screw shape is formed on the inner peripheral surface of the through hole of the protrusion 212a, and no screw shape is formed on the through hole of the protrusion 211a. The fastening portion 214 is screwed into the through hole of the protruding portion 212a through the through hole of the protruding portion 211a.

As a result, by rotating the fastening portion 214, the protruding portion 211a is pressed against the protruding portion 212a by the head of the fastening portion 214, and the resin pipe 11 can be clamped by the first clamp portion 210. The fastening portion 214 is not limited to screws, but may be bolts and nuts, for example, and the configuration is limited as long as the first semi-annular portion 211 and the second semi-annular portion 212 can be tightened. is not it.

The position fixing portion 215 is a screw member and is provided on the guide support portion 211b. Specifically, the guide support portion 211b is formed with a screw hole toward the through hole into which the guide member 230 is inserted, and the position fixing portion 215 is inserted into the screw hole.

When the position fixing portion 215 is tightened, the tip of the position fixing portion 215 comes into contact with the guide member 230, so that the position of the first clamp portion 210 with respect to the guide member 230 is fixed.

The second clamp portion 220 has a first semi-annular portion 221, a second semi-annular portion 222, a hinge portion 223, and a fastening portion 224.

The first semi-annular portion 221 has the same shape as the first semi-annular portion 211, and has a protruding portion 221a, a guide support portion 221b, and a screw portion 221c. Unlike the guide support portion 211b, the guide member 230 is fixed to the guide support portion 221b.

Further, the second semi-annular portion 222 has the same shape as the second semi-annular portion 212, and has a protruding portion 222a, a guide support portion 222b, and a guide support portion 222c. Unlike the guide support portions 212b and 212c, the guide member 230 is fixed to the guide support portions 222b and 222c.

The hinge portion 223 is the same as the hinge portion 213, and rotatably connects the peripheral ends of the first semi-annular portion 221 and the second semi-annular portion 222. The fastening portion 224 is the same as the fastening portion 214, and is provided on the protruding portion 221a and the protruding portion 222a.

The guide member 230 is fixed to the guide support portion 221b by inserting the guide support portion 211b. The guide member 230 is fixed to the guide support portion 222b by inserting the guide support portion 212b. The guide member 230 is fixed to the guide support portion 222c by inserting the guide support portion 212c.

The pressure screw member 240 is a ball screw and is inserted into the screw portion 211c and the screw portion 221c. The screw portion 211c and the screw portion 221c are formed with screw holes through which the pressure screw member 240 is inserted, and the screw portions 211c and the screw portion 221c are formed with screw holes in the opposite direction. That is, when the pressure screw member 240 is rotated, the first clamp portion 210 and the second clamp portion 220 approach or separate from each other along the guide member 230.

As shown in FIG. 8, the resin tube 11 is sandwiched and fixed by the first clamp portion 210, the resin tube 12 is sandwiched and fixed by the second clamp portion 220, and then the pressure screw member 240 is rotated. The first clamp portion 210 and the second clamp portion 220 are brought close to each other (see arrows A1 and A2).

As a result, the resin tube 11 and the resin tube 12 are pressed so that the tube end 11a of the resin tube 11 is pressed against the first side surface 22a of the stopper portion 22 and the tube end 12a of the resin tube 12 is pressed against the second side surface 22b of the stopper portion 22. Can be pressurized.

Further, by tightening the position fixing portion 215 in the pressurized state, the pressurized state by the first clamp portion 210 and the second clamp portion 220 can be maintained.

Next, in step S3, in a pressurized state, the second connector 82 of the electric fusion device 8 is attached to the two pins 61b and 61c of the second connector attachment portion 6, and energization is started. The pressure screw member 240 may be rotated while energizing to push the resin pipe 11 and the resin pipe 12 into the electric fusion splicer 1. The heating wire temperature at the time of energization may be any temperature as long as it can melt the main body 2, and in the case of polyolefin, it is preferably 220 degrees or less. This energization causes the heating wire 41 to generate heat. Step S3 corresponds to an example of the first energization step.

Next, in step S4, the first connector 81 of the electric fusion device 8 is attached to the two pins 51b and 51c of the first connector attachment portion 5 in a pressurized state, and energization is performed for a predetermined time. As described above, the time from the start of step S3 to the start of step S4 depends on the performance of the electric fusion splicer 1, the coil of the heating wire, and the nominal diameter of the pipe, but is preferably about 10 to 20 seconds. Step S4 corresponds to an example of the second energization step.

Next, after a predetermined time has elapsed from step S3, in step S5, energization of the two pins 61b and 61c by the electric fusion device 8 is completed.

Then, after a predetermined time has elapsed from step S4, in step S6, energization of the two pins 51b and 51c by the electric fusion device 8 is completed.

<Characteristics>
The fusion method in the present embodiment is an electric fusion joint 1 including a tubular portion 21, a stopper portion 22, a socket heat generating portion 3, and a stopper heating portion 4, and resin pipes 11 and 12 (tubes). A fusion method for fusing (an example), comprising: step S1 (an example of an insertion step), step S3 (an example of a first energization step), and step S4 (an example of a second energization step). .. The tubular portion 21 has joint receiving portions 23, 24 into which resin pipes 11 and 12 containing a thermoplastic resin can be inserted inward. The stopper portion 22 is provided so as to project inward on the inner surface of the tubular portion 21, and when the resin pipes 11 and 12 are inserted inside the joint receiving portions 23 and 24, the pipe ends of the resin pipes 11 and 12 are formed. The insertion positions of 11a and 12a can be regulated. The receiving port heating unit 3 includes a heating wire 31 arranged in the joint receiving ports 23 and 24. The stopper heating unit 4 includes a heating wire 41 arranged on the stopper unit 22. In step S1, the resin pipes 11 and 12 are inserted inside the joint receiving portions 23 and 24 of the electric fusion joint 1. Step S3 starts energizing the stopper heating unit 4. In step S4, energization of the receiving port heating unit 3 is started after the energization of the stopper heating unit 4 is started.

By energizing the stopper heat generating portion 4, the pipe ends 11a and 12a of the resin pipes 11 and 12 and the stopper portion 22 are fused, and by energizing the receiving port heating portion 3, the outer peripheral surface of the resin pipes 11 and 12 and the joint receiver are received. The inner peripheral surfaces of the mouth portions 23 and 24 are fused. Clearance formed between the resin pipes 11 and 12 and the electric fusion joint 1 (clearance W2 between the pipe ends 11a and 12a of the resin pipes 11 and 12 and the stopper portion 22 and the outer peripheral surface of the resin pipes 11 and 12). Since the clearance W1 between the inner peripheral surfaces of the joint receiving portions 23 and 24 is non-uniform and wide, the molten resin will flow into a place where it is easy to flow. For example, the resin melted on the outer peripheral surfaces of the resin pipes 11 and 12 and the inner peripheral surfaces of the joint receiving portions 23 and 24 is unevenly distributed between the pipe ends 11a and 12a of the resin pipes 11 and 12 and the stopper portion 22. When it flows in, the swelling of the fused resin between the stopper portion 22 and the pipe ends 11a and 12a of the resin pipes 11 and 12 becomes non-uniform in the circumferential direction, and in some cases, a gap (which can be said to be a dent) is formed in the swelling. May occur. FIG. 9A shows a state in which the swelling R of the resin is non-uniform in the circumferential direction C. In FIG. 9A, the resin swelling inward from the inner peripheral surface of the stopper portion 22 and the resin tube 11 is indicated by R, and the dent is indicated by Q.

On the other hand, in the present embodiment, by energizing the stopper heat generating portion 4 before the receiving port heating portion 3, the space between the inner peripheral surface of the joint receiving portions 23 and 24 and the outer peripheral surface of the resin pipes 11 and 12 Between the stopper portion 22 and the pipe ends 11a and 12a of the resin pipes 11 and 12 so that the resin melted in 1 does not flow unevenly between the stopper portion 22 and the pipe ends 11a and 12a of the resin pipes 11 and 12. Can be filled with melted or hardened resin. Therefore, it is possible to suppress non-uniformity of the swelling of the resin in the circumferential direction. It is preferable that the above-mentioned melted resin is hardened to the extent that the inflow of the resin can be prevented. FIG. 9B shows a state in which the swelling R of the resin is uniform in the circumferential direction C. FIG. 10 is a cross-sectional view showing a state in which the stopper portion 22 of the electric fusion joint 1 and the pipe ends 11a and 12a of the resin pipes 11 and 12 are fused by the heat generated by the stopper heat generating portion 4. In order to make the fusion of the stopper portion 22 easy to understand, FIG. 10 does not show the fusion between the electric fusion joint 1 and the resin pipes 11 and 12 due to the heat generated by the socket heat generating portion 3.

As in the present embodiment, by raising the resin over the entire circumference in the circumferential direction C, it is possible to suppress dents and prevent the generation of dead water, so that it can be suitably used in the field related to ultrapure water. can. In particular, it is suitable for the field of ultrapure water used for cleaning water for semiconductors. Further, since the resin is not dented, the ends of the resin tubes 11 and 12 can be prevented from coming into contact with the fluid. Further, by making the swelling uniform, it is possible to prevent the resin from being partially removed or the current transformer from occurring.
Further, as shown in FIG. 10, the abutting portion between the stopper portion 22 and the pipe ends 11a and 12a of the resin pipes 11 and 12 due to fusion is covered with resin when viewed in a cross section along the axial direction A. (Refer to the swelling R of the resin in the figure), it is formed so that water does not stay.

Further, since the stopper portion 22 and the pipe ends 11a and 12a of the resin pipes 11 and 12 facing each other are in a narrow range, the amount of melted resin is small, the amount of resin rising inward can be reduced, and the pressure loss can be reduced. Can be suppressed.

Further, in the electric fusion joint 1 of the present embodiment, the tubular portion 21, the stopper portion 22, the receiving port heating portion 3, the stopper heating portion 4, the pair of pins 51b and 51c, and the pair of pins 61b , 61c and. The tubular portion 21 has a tubular portion and has joint receiving portions 23, 24 into which resin pipes 11 and 12 containing a thermoplastic resin can be inserted inward. The stopper portion 22 is provided so as to project inward on the inner surface 21a of the tubular portion 21, and is a pipe of the resin pipes 11 and 12 when the resin pipes 11 and 12 are inserted inside the joint receiving portions 23 and 24. The insertion positions of the ends 11a and 12a can be regulated. The receiving port heating unit 3 includes a heating wire 31 arranged in the joint receiving ports 23 and 24. The stopper heating unit 4 includes a heating wire 41 arranged on the stopper unit 22. The pair of pins 51b and 51c are connected to the heating wire 31 of the receiving port heating unit 3 in order to energize the receiving port heating unit 3. The pair of pins 61b and 61c are connected to the heating wire 41 of the stopper heating unit 4 in order to energize the stopper heating unit 4.

As described above, the heating wire 41 of the stopper heating unit 4 and the heating wire 31 of the receiving port heating unit 3 are not connected, and separately have pins 51b and 51c and pins 61b and 61c which are a pair of terminals for energization. Therefore, the timing of energizing the stopper heating unit 4 and the timing of energizing the receiving port heating unit 3 can be staggered.

Therefore, the fusion by the stopper heating unit 4 and the fusion by the receiving port heating unit 3 can be individually controlled, and the energization timing to the stopper heating unit 4 depends on the material and size of the electric fusion joint 1 and the pipe. By advancing either one of the timings of energization to the heat receiving portion 3 and the timing of energization, it is possible to suppress the formation of gaps and the uneven swelling of the resin.

<Other embodiments>
Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the invention.

(A)
In the above embodiment, the energization of the socket heating unit 3 is started after the stopper heating unit 4 is energized, but the reverse may be performed. That is, the stopper heating unit 4 may be energized after the energization of the receiving port heating unit 3 is started.

The fusion method in this case is shown in the flow chart of FIG. As shown in FIG. 11, after step S2, in step S30, energization is started in the receiving port heating unit 3. After that, energization of the stopper heating unit 4 is started. Further, although it depends on the energization time in each of the receiving port heating unit 3 and the stopper heating unit 4, if the interval between step S30 and step S40 is 10 to 20 seconds as described above, in the next step S50 of step S40. , The energization of the stopper heating unit 4 is stopped. Finally, in step S60, the energization of the receiving port heating unit 3 is stopped.

For example, the resin melted between the pipe ends 11a and 12a of the resin pipes 11 and 12 and the stopper portion 22 provides a clearance between the inner surface of the joint receiving portions 23 and 24 and the outer peripheral surface of the resin pipes 11 and 12. When it flows in, the swelling of the fused resin between the stopper portion 22 and the tube ends 11a and 12a of the resin tubes 11 and 12 becomes non-uniform in the circumferential direction, and in some cases, a gap may be formed in the swelling.

On the other hand, as described above, in step S30 (an example of the first energization step), after starting the energization of the socket heat generating portion 3, in step S40 (an example of the second energizing step), the stopper heat generating portion 4 is energized. In order to fill a wide range of clearance between the inner peripheral surfaces of the joint receiving portions 23 and 24 and the outer peripheral surfaces of the resin pipes 11 and 12 with the melted resin or the solidified resin, the stopper portion 22 and the resin are started. It is possible to prevent the molten resin from flowing between the inner peripheral surface of the joint receiving portions 23 and 24 and the outer peripheral surface of the resin pipes 11 and 12 between the pipe ends 11a and 12a of the pipes 11 and 12. Therefore, it is possible to suppress non-uniformity of the swelling of the resin in the circumferential direction. Further, since the non-uniformity of the swelling can be suppressed, the dent of the resin does not occur, and the end of the pipe can be prevented from coming into contact with the fluid.

(B)
In the above embodiment, the outer diameter of the stopper portion 22 is circular when viewed along the axial direction A, but it is not limited to a circle and may be a polygonal shape.

(C)
In the above embodiment, the receiving port heat generating portion 3 is provided symmetrically with the stopper portion 22 interposed therebetween, but the present invention is not limited to this. For example, the heating wire 31 is provided so as to come into contact with each other three times at each joint receiving portion 23 with the stopper portion 22 interposed therebetween, and the heating wire 31 comes into contact with each other two turns at the other joint receiving portion 24. It may be provided in.

(D)
In the above embodiment, the flow path of the electric fusion joint 1 is formed in a straight line, but it may be an elbow joint in which the flow path is curved.

(E)
In the above embodiment, since the same heating wire 31 of the receiving port heating unit 3 and the heating wire 41 of the stopper heating unit 4 are used, all the heating wires 31 and 41 are provided with an insulating film. , It does not have to be limited to this. However, it is preferable that at least the heating wire 41 is provided with an insulating film. This is because the resin pipe 11 and the resin pipe 12 may pressurize the heating wires 41 so that the heating wires 41 are likely to come into contact with each other.

(F)
In the above embodiment, the tube end 11a of the resin tube 11 and the tube end 12a of the resin tube 12 are pressed against the stopper portion 22, but they do not have to be pressed. However, in order to suppress the generation of clevis, it is preferable to press it, and the construction time can be shortened.

(G)
In the above embodiment, the receiving port heating unit 3 is in contact with the same number of turns (2 turns), but the contact is not limited to this. The number of turns in contact with each other may be different.

(H)
In the above embodiment, the resin pipes 11 and 12 are used, but the present invention is not limited to this, and a pipe using a resin such as a metal reinforcing composite pipe having a metal reinforcing layer may be used.

The electrically fused joint of the present invention has an effect of suppressing the formation of gaps and the uneven swelling of resin, and is useful as, for example, a piping structure for ultrapure water.

1: Electric fusion joint 3: Receptacle heat generation part 4: Stopper heat generation part 11: Resin pipe 12: Resin pipe

Claims (3)

A cylindrical part having a joint receiving part into which a tube containing a thermoplastic resin can be inserted inside,
A stopper portion provided so as to project inward on the inner surface of the tubular portion and capable of regulating the insertion position of the pipe end of the pipe when the pipe is inserted inside the joint receiving portion.
A receiving heat generating part including a heating wire arranged in the joint receiving part, and
A fusion method for fusing an electrically fused joint provided with a stopper heating portion including a heating wire arranged in the stopper portion and the pipe.
An insertion step of inserting the pipe inside the joint receiving portion of the electrically fused joint, and
The first energization step of starting energization of the stopper heat generating portion and
A second energization step of starting energization of the receiving port heating portion after the start of energizing the stopper heating portion is provided.
Fusion method. A cylindrical part having a joint receiving part into which a tube containing a thermoplastic resin can be inserted inside,
A stopper portion provided so as to project inward on the inner surface of the tubular portion and capable of regulating the insertion position of the pipe end of the pipe when the pipe is inserted inside the joint receiving portion.
A receiving heat generating part including a heating wire arranged in the joint receiving part, and
A fusion method for fusing an electrically fused joint provided with a stopper heating portion including a heating wire arranged in the stopper portion and the pipe.
An insertion step of inserting the pipe inside the joint receiving portion of the electrically fused joint, and
The first energization step of starting energization of the heat receiving portion of the socket and
A second energization step of starting energization of the stopper heat generating portion after the start of energization of the receiving port heating portion is provided.
Fusion method. A cylindrical part having a joint receiving part into which a tube containing a thermoplastic resin can be inserted inside,
A stopper portion provided so as to project inward on the inner surface of the tubular portion and capable of regulating the insertion position of the pipe end of the pipe when the pipe is inserted inside the joint receiving portion.
A receiving heat generating part including a heating wire arranged in the joint receiving part, and
A stopper heat generating portion including a heating wire arranged in the stopper portion and
A pair of first terminals connected to the heating wire of the heat receiving part to energize the heat receiving part of the receiving port, and a pair of first terminals.
A pair of second terminals connected to a heating wire of the stopper heating portion for energizing the stopper heating portion.
Electric fusion fitting.

Images