Connection Method

Abstract

To provide a connection method capable of evaluating a connection between a pipe material or a joint member and an electric fusion joint.SOLUTION: A step S1 in a connection method includes shaving a predetermined part of an outer surface 350 of a pipe material 300 such that at least a portion is exposed from an electric fusion joint 100 when the pipe material 300 is inserted inside the electric fusion joint 100 to create a second outer peripheral part 340 for evaluating a connection state. A step S2 includes inserting the pipe material 300 inside the electric fusion joint 100. A step S5 includes energizing and heating the electric fusion joint 100 after the step S2. A step S6 includes pressing the pipe material 300 onto the electric fusion joint 100 after the step S2. A step S8 includes checking a positional relationship of the second outer peripheral part 340 to the electric fusion joint 100 after starting the step S5 and the step S6, and comparing the positional relationship of the second outer peripheral part 340 to the electric fusion joint 100 prior to the step S5 to evaluate the connection state.SELECTED DRAWING: Figure 18

Description

[Technical Field]

[0001] The present disclosure relates to a method for connecting a pipe or a joint member to an electrofusion joint. [Background technology]

[0002] Resin pipes and joints are used for water pipes, gas pipes, etc., and electrofusion joints are used to connect them to other pipes and joints at construction sites, etc. (see, for example, Patent Document 1).

[0003] For example, the electrofusion joint shown in Patent Document 1 includes a joint body made of thermoplastic resin with pipe receptacles at both ends into which the pipe to be connected is inserted, and a stopper portion that protrudes inward from the inner circumferential surface of the joint body. The stopper portion regulates the position of the pipe inserted into the pipe receptacle. A heating element is provided in each of the pipe receptacle and the stopper portion, and by generating heat from the heating element, the resin around the heating element fuses with the resin of the pipe, connecting the electrofusion joint and the pipe. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 5-87286 Summary of the Invention [Problem to be solved by the invention]

[0005] However, since fusion with the pipe material or joint member occurs inside the electric fusion joint, it is difficult to confirm whether or not the fusion connection has been performed satisfactorily.

[0006] An object of the present disclosure is to provide a connection method that makes it possible to evaluate the connection between a pipe material or a joint member and an electrofusion joint. [Means for solving the problem]

[0007] To achieve the above object, a first aspect of the present invention provides a connection method for connecting a tubular material or a coupling member to an electrofusion joint, the connection method comprising a scraping step, an insertion step, a heating step, a pressing step, and an evaluation step. The scraping step involves scraping a predetermined portion of the outer surface of the tubular material or coupling member so that at least a portion of the tubular material or coupling member is exposed from the electrofusion joint when the tubular material or coupling member is inserted into the electrofusion joint, thereby creating an indicator portion for evaluating the connection condition. The insertion step involves inserting the tubular material or coupling member into the electrofusion joint. The heating step involves applying electricity to the electrofusion joint to heat it after the confirmation step. The pressing step involves pressing the tubular material or coupling member against the electrofusion joint or against another tubular material or coupling member inserted into the electrofusion joint on the opposite side. The evaluation step involves, after the heating and pressing steps have been initiated, checking the positional relationship of the indicator portion relative to the electrofusion joint and comparing it with the positional relationship of the indicator portion relative to the electrofusion joint before the heating step to evaluate the connection condition.

[0008] While the electrofusion joint is heated, the tubing or joint member is pressed against the electrofusion joint or against another tubing or joint member inserted into the electrofusion joint, forcing the tubing or joint member into the inside of the electrofusion joint and forming a bead at the fused portion. If the bead height is greater than a predetermined value, the fusion connection can be evaluated as good, and the greater the amount by which the tubing or joint member is pressed into the inside of the electrofusion joint, the higher the bead height.

[0009] Therefore, by checking the positional relationship between the electrofusion joint and the indicator portion before and after the start of the heating and pressing steps, it is possible to evaluate the connection between the pipe material or joint member and the electrofusion joint.

[0010] For example, by using a pipe or fitting member whose outer surface and inner surface are different colors, the scraped indicator portion has a different color from the other portions, making the position of the indicator portion easier to see. Even if the scraped indicator portion has the same color as the other portions, the position of the indicator portion can be confirmed by the difference in level between the scraped portion and the other portions.

[0011] A connecting method according to a second aspect is the connecting method according to the first aspect, wherein the positional relationship includes the length from the end of the electrofusion joint to the end of the indicator portion. In the evaluation step, the length from the end of the electrofusion joint to the end of the indicator portion is measured, and if the amount of shrinkage of the measured length from the end of the electrofusion joint to the end of the indicator portion before the heating step is greater than a predetermined amount, the connection state is evaluated as good.

[0012] This allows the connection to be evaluated based on the amount of shortening of the length from the end of the electrofusion joint to the end of the indicator portion from before the start of heating to after the start of heating.

[0013] A third aspect of the connecting method is the same as the second aspect, except that the indicator portion is positioned so as to straddle the end of the electrofusion joint in the evaluation step, and the positional relationship includes the length from the end of the electrofusion joint to the end of the indicator portion on the opposite side to the electrofusion joint.

[0014] This allows the connection to be evaluated based on the amount by which the length from the end of the electrofusion joint to the end of the indicator portion opposite the electrofusion joint has shortened from before the start of heating to after the start of heating.

[0015] A connecting method according to a fourth aspect is the connecting method according to any one of the first to third aspects, further comprising a confirmation step, which is performed after the insertion step and before the heating step, to confirm the positional relationship of the indicator portion with respect to the electrofusion joint.

[0016] This allows the positional relationship of the indicator portion to the electric fusion joint before heating begins to be accurately grasped, allowing for precise evaluation of the connection.

[0017] A connecting method according to a fifth aspect is the connecting method according to the first aspect, wherein the electrofusion joint has a joint socket portion and a socket heating portion. A pipe or joint member is inserted into the joint socket portion. The socket heating portion is disposed in the joint socket portion. The scraping step scrapes a predetermined portion and also scrapes a predetermined range of the outer peripheral surface end portion from the end face of the pipe or joint member. In the heating step, the outer peripheral surface end portion is disposed opposite the socket heating portion.

[0018] In this way, the edge portion of the outer surface, which is the fused portion with the fitting socket portion, and the specified portion which serves as the indicator portion are scraped simultaneously, so by checking the indicator portion after the connection is completed, it is possible to confirm that the scraping process has been carried out on the fused portion.

[0019] A sixth aspect of the connecting method is the connecting method of the fifth aspect, wherein the electrofusion joint has a tubular portion, a stopper portion, and a stopper heating portion. The tubular portion includes a fitting socket portion. The stopper portion is provided on the inner surface of the tubular portion so as to protrude inward, and is pressed against the end face of a pipe or fitting member inserted into the fitting socket portion. The stopper heating portion is disposed on the stopper portion. The scraping process scrapes the end face of the pipe or fitting member at the same time as scraping the predetermined portion and the end portion of the outer peripheral surface.

[0020] In this way, the end face that is the fused portion with the stopper portion, the end portion of the outer surface that is the fused portion with the fitting socket portion, and a specified portion that serves as the indicator portion are scraped simultaneously, so by checking the indicator portion after the connection is completed, it is possible to confirm that the scraping process has been carried out on the fused portion. [Effects of the Invention]

[0021] According to the present disclosure, it is possible to provide a connection method that makes it possible to evaluate the connection between a pipe material or a joint member and an electrofusion joint. [Brief explanation of the drawings]

[0022] [Figure 1]1 is a perspective view of a scraper device according to an embodiment of the present disclosure; [Figure 2] 1 is a perspective view of a scraper device according to an embodiment of the present disclosure; [Figure 3] 1 is a perspective view of a scraper device according to an embodiment of the present disclosure, viewed from above; [Figure 4] 1 is a perspective view showing a state in which a tube is inserted into a scraper device according to an embodiment of the present disclosure. FIG. [Figure 5] (a) A perspective view showing the end of a pipe material, (b) A perspective view showing the end of the pipe material after being scraped by a scraper device. [Figure 6] (a) An oblique view showing the main body member, lid portion, first roller, second roller and end surface blade of the scraping device of an embodiment according to the present disclosure, (b) a side view showing the vicinity of arrow C in Figure 6(a) in a direction perpendicular to the central axis. [Figure 7] FIG. 2 is a plan view of the scraper device with the lid removed. [Figure 8] FIG. 10 is a perspective view showing an outer peripheral blade member of the scraper device; [Figure 9] 9(a) is a cross-sectional view of the scraper device taken along the line EE′ in FIG. 7, and FIG. 9(b) is an enlarged view of part F in FIG. 9(a). [Figure 10] 10(a) is a cross-sectional view of the scraper device taken along the line FF' in FIG. 9, and FIG. 10(b) is a view showing a state in which the cam member has been rotated from the state shown in FIG. 10(a). [Figure 11A] 10 is a cross-sectional view showing a state in which a tubular material is inserted into the scraper device and the first outer periphery blade and the second outer periphery blade are biting into the tubular material. FIG. [Figure 11B] 11B is a diagram showing the state after scraping processing from the state of FIG. 11A. [Figure 12] 1A and 1B are diagrams illustrating an electrofusion joint according to an embodiment of the present disclosure, tubing materials connected by the electrofusion joint, and the tubing materials. [Figure 13] FIG. 2 is a cross-sectional view of an electric fusion joint. [Figure 14] FIG. 1 is a cross-sectional view of an electric fusion joint with a pipe material inserted. [Figure 15] FIG. 1 is a perspective view showing a jig according to an embodiment of the present disclosure. [Figure 16]FIG. [Figure 17] FIG. 10 is a diagram showing a pipe material, an electrofusion joint, and the pipe material attached to a jig. [Figure 18] FIG. 1 is a flow diagram showing a connection method according to an embodiment of the present disclosure. [Figure 19] (a) A diagram showing the state of the electric fusion joint and the tubing material near the first clamping part before fusion, (b) A diagram showing the state of the electric fusion joint and the tubing material near the first clamping part after fusion. [Figure 20] FIG. 2 is a cross-sectional view showing the pipe material, the electrofusion joint, and the pipe material in a fused and connected state. [Figure 21] FIG. 1A is a diagram showing a tubing material and an electrofusion joint before fusion in a modified example of this embodiment; (a) is a diagram showing a tubing material and an electrofusion joint after fusion in a modified example of this embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0024] (Scraper device 1) Fig. 1 is a perspective view of a scraper device 1 of this embodiment. Fig. 2 is a perspective view of the scraper device 1 viewed from a different direction than Fig. 1. Fig. 3 is a perspective view of the scraper device 1 viewed from above. Fig. 4 is a perspective view showing a state in which a pipe material 300 is inserted into the scraper device 1.

[0025] A pipe material 300 is inserted into the scraper device 1 shown in Figures 1 to 3, and the outer peripheral surface and end face of the end of the pipe material 300 are scraped by rotating the pipe material 300 in one direction A relative to the scraper device 1 as shown in Figure 4.

[0026] First, the pipe material 300 to be scraped by the scraper device 1 will be described.

[0027] Figure 5(a) is a perspective view showing the end 310 of the tubular material 300. Figure 5(b) is a perspective view showing the end 310 of the tubular material 300 after it has been scraped by the scraper device 1. In Figure 5(b), dots are applied to the scraped portion.

[0028] The pipe material 300 is made of a thermoplastic resin. Specifically, the pipe material 300 is made of a polyolefin such as polyethylene.

[0029] As shown in FIG. 5(b), the end face 320, first outer peripheral portion 330, and second outer peripheral portion 340 of the tubular member 300 are scraped. The end face 320 is the end face of the end portion 310 of the tubular member 300. The first outer peripheral portion 330 is a portion of the outer peripheral surface 350 that extends from the end face 320 along the axial direction J of the tubular member 300 within a predetermined range. The second outer peripheral portion 340 is a portion of the outer peripheral surface 350 that extends within a predetermined range at a predetermined distance from the first outer peripheral portion 330 in the axial direction J. The second outer peripheral portion 340 is used as an index portion for evaluating the connection condition between the electrofusion joint 100 and the tubular member 300. An unscraped portion 360 is provided between the first outer peripheral portion 330 and the second outer peripheral portion 340 of the tubular member 300.

[0030] A coating is formed on the outer peripheral surface 350 of the pipe material 300, and the coating is a different color from the other portions. For example, the coating can be blue and the inner portion can be white. In this case, the first outer peripheral portion 330 and the second outer peripheral portion 340 are white, and the other portions of the outer peripheral surface 350 are blue.

[0031] Next, the scraper device 1 that scrapes the end surface 320, the first outer peripheral portion 330, and the second outer peripheral portion 340 of the pipe material 300 will be described in detail.

[0032] As shown in Figure 1, the scraper device 1 comprises a main body member 2, a cover portion 3, a first roller 4, a second roller 5, an end surface blade 6 (see Figure 3), a biasing member 7, an outer peripheral blade member 8, a cam member 9, and a lever 10.

[0033] FIG. 6(a) is a perspective view showing the main body member 2, the cover portion 3, the first roller 4, the second roller 5 and the end face blade 6. FIG.

[0034] (Main body member 2) 6(a), the main body member 2 has a base 11, a first pillar 12, a second pillar 13, and a third pillar 14. The base 11 is substantially disk-shaped.

[0035] The base 11 has a front surface 15 and a back surface 16. The distance between the front surface 15 and the back surface 16 is the thickness of the base 11. The front surface 15 of the base 11 has a first surface portion 15a and a second surface portion 15b. A step 15c is formed between the first surface portion 15a and the second surface portion 15b. The back surface 16 is formed flat. The thickness from the second surface portion 15b to the back surface 16 is thinner than the thickness from the first surface portion 15a to the back surface. The front surface 15 is divided into the first surface portion 15a and the second surface portion 15b by the step 15c formed to connect two points on the outer edge. The first surface portion 15a is formed to include the central axis B of the base 11. The central axis B coincides with the axial direction J when the pipe material 300 is inserted into the scraper device 1.

[0036] The first pillar 12, the second pillar 13, and the third pillar 14 are arranged on the surface 15 of the base 11. The first pillar 12, the second pillar 13, and the third pillar 14 are arranged perpendicular to the surface 15. The first pillar 12, the second pillar 13, and the third pillar 14 are arranged on the first surface portion 15a. The first pillar 12, the second pillar 13, and the third pillar 14 are arranged near the outer periphery of the base 11, along the axis of the central axis B. The first pillar 12 and the third pillar 14 are arranged near the step 15c. The second pillar 13 is arranged between the first pillar 12 and the third pillar 14 along the axis of the central axis B. The step 15c is formed to connect the first pillar 12 and the third pillar 14.

[0037] (Lid part 3) The lid portion 3 is supported by a first pillar 12, a second pillar 13, and a third pillar 14. The lid portion 3 is fixed to the tips of the first pillar 12, the second pillar 13, and the third pillar 14. The lid portion 3 is ring-shaped. An opening 3a (an example of an insertion port) is formed on the inside of the lid portion 3. The lid portion 3 is shaped like a disk with an opening 3a formed in the center. The pipe material 300 is inserted through this opening 3a.

[0038] (First roller 4, second roller 5) The first roller 4 and the second roller 5 are arranged parallel to the central axis B. In the circumferential direction around the central axis B, the first roller 4 is arranged between the first pillar 12 and the second pillar 13, and the second roller 5 is arranged between the second pillar 13 and the third pillar 14.

[0039] One end of the first roller 4 is rotatably supported by the base 11, and the other end is rotatably supported by the lid portion 3. One end of the second roller 5 is rotatably supported by the base 11, and the other end is rotatably supported by the lid portion 3. The first roller 4 and the second roller 5 are rotatable around a central axis that is parallel to the central axis B. The first roller 4 and the second roller 5 are capable of abutting against the outer peripheral surface 350 of the inserted tubular material 300, and rotate together with the rotation of the tubular material 300.

[0040] (end face blade 6) The end face blade 6 cuts the end face 320 of the tubular material 300. As shown in Figures 3 and 6(a), the end face blade 6 is arranged on the first surface portion 15a of the surface 15 of the base 11. Figure 6(b) is a side view showing the vicinity of arrow C in a direction perpendicular to the central axis B. The end face blade 6 is arranged to protrude from the first surface portion 15a. The end face 320 of the tubular material 300 is cut from the tip 6a of the end face blade 6 to the first surface portion 15a by a distance d1.

[0041] (biasing member 7) The biasing member 7 biases the outer peripheral blade member 8 toward the central axis B. FIG. 7 is a plan view of the scraper device 1 with the cover portion 3 removed. The biasing member 7 is formed by bending a substantially plate-shaped member. The biasing member 7 is an L-shaped member in a plan view. The biasing member 7 has a first portion 21 and a second portion 22. The first portion 21 and the second portion 22 are plate-shaped. The first portion 21 is fixed to the outer surface 12a of the first pillar 12. The first portion 21 protrudes from the first pillar 12 toward the second surface portion 15b. The second portion 22 is arranged to extend from the protruding tip of the first portion 21 substantially parallel to the step 15c. The outer peripheral blade member 8 is fixed to the tip portion 22a of the second portion 22.

[0042] (Outer peripheral blade member 8) The outer peripheral blade member 8 cuts the first outer peripheral portion 330 and the second outer peripheral portion 340 of the tubular material 300. The outer peripheral blade member 8 is disposed between the first pillar 12 and the third pillar 14. As shown in FIG. 7, the outer peripheral blade member 8 is disposed above the second surface portion 15b and generally along the step 15c. The end portion 310 of the tubular material 300 is inserted into a space S surrounded by the base 11, the first pillar 12, the second pillar 13, the third pillar 14, the first roller 4, the second roller 5, the biasing member 7, and the outer peripheral blade member 8. The central axis B is the center of the space S and coincides with the insertion direction of the tubular material 300.

[0043] 8(a) is a perspective view showing the outer peripheral blade member 8. The outer peripheral blade member 8 has a first outer peripheral blade 31, a second outer peripheral blade 32, an abutment surface 37a, an attachment portion 34, and an abutment portion 30. The first outer peripheral blade 31 cuts a first outer peripheral portion 330 of the pipe material 300. The second outer peripheral blade 32 cuts a second outer peripheral portion 340 of the pipe material 300. The abutment surface 37a abuts against an outer peripheral surface 350 of the pipe material 300. The attachment portion 34 is attached to the biasing member 7.

[0044] The outer peripheral blade member 8 is a substantially plate-shaped member. As shown in FIG. 8(a), the outer peripheral blade member 8 includes a first edge portion 35, a second edge portion 36, and a central portion 37. The first edge portion 35 is an edge portion of the outer peripheral blade member 8 on the base 11 side and is formed substantially parallel to the second surface portion 15b. The second edge portion 36 is a portion of the outer peripheral blade member 8 on the lid portion 3 side and is formed substantially parallel to the second surface portion 15b. The central portion 37 is a portion between the first edge portion 35 and the second edge portion 36 of the outer peripheral blade member 8. A surface 35a of the first edge portion 35 facing the space S and a surface 36a of the second edge portion 36 facing the space S are disposed substantially parallel to the central axis B. An abutment surface 37a, which is the surface of the central portion 37 facing the space S, is disposed substantially parallel to the central axis B. The first edge portion 35 protrudes toward the space S more than the central portion 37. The second edge portion 36 protrudes further toward the space S than the central portion 37.

[0045] A cutout portion 38 is formed extending from the first edge portion 35 to the central portion 37. A cutout portion 39 is formed extending from the second edge portion 36 to the central portion 37. The first cutout portion 38 and the second cutout portion 39 are arranged side by side in a direction parallel to the central axis B.

[0046] 7, the attachment portion 34 is the end portion of the outer peripheral blade member 8 on the first pillar 12 side. The attachment portion 34 is arranged closer to the first pillar 12 side than the first cutout portion 38 and the second cutout portion 39.

[0047] 8(a), the first outer peripheral blade 31 is formed at the end of the first edge portion 35 on the opposite side of the first cutout portion 38 from the mounting portion 34. The edge 38a of the first cutout portion 38 on the opposite side of the mounting portion 34 is formed to be inclined so as to be positioned closer to the mounting portion 34 as it approaches the surface 35a. The part of the edge 38a that protrudes toward the space S beyond the abutment surface 37a of the center portion 37 forms the first outer peripheral blade 31.

[0048] 9(a) is a cross-sectional view of the scraper device 1 taken along the line E-E' in FIG. 7. FIG. 9(b) is an enlarged view of the N portion of FIG. 9(a). As shown in FIGS. 9(a) and 9(b), the outer peripheral cutting member 8 is disposed outside the step 15c (the opposite side of the central axis B). In a side view perpendicular to the axis B, the outer peripheral cutting first blade 31 overlaps with the first surface portion 15a. In other words, the outer peripheral cutting first blade 31 overlaps with the first surface portion 15a in a position parallel to the axis B. Specifically, as shown in FIG. 9(b), the first end 31a of the outer peripheral cutting first blade 31 on the base 11 side is disposed closer to the back surface 16 (the opposite side of the opening 3a) than the first surface portion 15a. Furthermore, the second end 31b of the outer peripheral cutting first blade 31 on the opening 3a side is disposed closer to the opening 3a than the first surface portion 15a.

[0049] 9(b), the tip 6a of the edge cutting blade 6 overlaps with the outer peripheral first blade 31. In other words, the tip 6a of the edge cutting blade 6 overlaps with the outer peripheral first blade 31 in a position parallel to the axis B. In detail, as shown in FIG. 9(b), the first end 31a of the outer peripheral first blade 31 on the base 11 side is located closer to the back surface 16 (opposite the opening 3a) than the tip 6a of the edge cutting blade 6. Furthermore, the second end 31b of the outer peripheral first blade 31 on the opening 3a side is located closer to the opening 3a than the tip 6a of the edge cutting blade 6.

[0050] 8(a), the outer periphery second blade 32 is formed at the end of the second edge portion 36 on the opposite side of the second cutout portion 39 from the mounting portion 34. An edge 39a of the second cutout portion 39 on the opposite side of the mounting portion 34 is formed to be inclined so as to be positioned closer to the mounting portion 34 as it approaches the surface 36a. The portion of the edge 39a that protrudes toward the space S beyond the abutment surface 37a of the center portion 37 forms the outer periphery second blade 32.

[0051] Fig. 8(b) is a plan view of the outer peripheral blade member 8. In this embodiment, the length by which the outer peripheral first blade 31 protrudes from the surface 36a is the same as the length by which the outer peripheral second blade 32 protrudes from the surface 36a, and is shown as d2. Note that the outer peripheral first blade 31 and the outer peripheral second blade 32 overlap in plan view, and therefore only the outer peripheral second blade 32 is shown in Fig. 8(b).

[0052] The outer peripheral surface 350 of the pipe material 300 comes into contact with the contact surface 37a, and the outer peripheral surface 350 of the pipe material 300 is cut away by the step d2.

[0053] The abutment portion 30 is the end portion of the outer peripheral blade member 8 on the third pillar 14 side. The end portion of the outer peripheral blade member 8 on the third pillar 14 side is urged toward the space S by the urging force of the urging member 7, and the abutment portion 30 is pressed against the cam member 9.

[0054] (Cam member 9, lever 10) When inserting the tubular material 300 into the space S, the cam member 9 moves the outer periphery first blade 31 and the outer periphery second blade 32 outward, and when cutting the outer peripheral surface 350 of the tubular material 300, the cam member 9 moves the outer periphery first blade 31 and the outer periphery second blade 32 toward the tubular material 300 (toward the space S).

[0055] As shown in FIG. 9(a), the cam member 9 is a rod-shaped member, one end of which is rotatably supported on the base 11, and the other end of which is rotatably supported on the lid portion 3. As shown in FIG. 1, the lever 10 protrudes from the cam member 9 near the lid portion 3. As shown in FIG. 7, the lever 10 extends toward the biasing member 7. An operator can rotate the cam member 9 by gripping and rotating the lever 10 (see arrow G in FIG. 10(a)).

[0056] Fig. 10(a) is a cross-sectional view of the scraper device 1 taken along the line FF' in Fig. 9(a). As shown in Fig. 10(a), the cam member 9 has a contact portion 9a, which the outer periphery blade member 8 contacts, formed in a D-shaped cross section.

[0057] As shown in FIG. 10(a), the first outer peripheral cutting blade 31 and the second outer peripheral cutting blade 32 are positioned in a scraping position where they scrape the outer peripheral surface 350 of the tubular material 300. In the scraping position, the abutting portion 30 of the outer peripheral cutting member 8 abuts against the flat portion 9b of the abutted portion 9a of the cam member 9. The flat portion 9b is positioned so as to generally follow the step 15c. By rotating the lever 10 outward from the state shown in FIG. 10(a), the cam member 9 rotates as shown in FIG. 10(b) (see arrow G). As the cam member 9 rotates, it is pushed by the edge of the flat portion 9b, and the outer peripheral cutting member 8 moves outward relative to the central axis B (see arrow H in FIG. 10(a)). This movement of the outer peripheral cutting member 8 expands the space S, allowing the tubular material 300 to be inserted into the space of the scraper device 1. The retracted position is the position of the first outer peripheral blade 31 and the second outer peripheral blade 32 when the outer peripheral blade member 8 is pushed outward by the cam member 19, as shown in Figure 10(b). From the state shown in Figure 10(b), the pipe material 300 is inserted into the space S until the end face 320 abuts the first surface portion 15a, and by returning the lever 10 to its original position, the cam member 9 rotates as shown in Figure 10(a), and the first outer peripheral blade 31 and the second outer peripheral blade 32 move to the cutting position and abut against the outer peripheral surface 350 of the pipe material 300.

[0058] 11A is a cross-sectional view showing a state in which a tubular material 300 is inserted into the scraper device 1 and the first outer periphery blade 31 and the second outer periphery blade 32 are abutted against the tubular material 300. In this state, the end face 320 of the end portion 310 of the tubular material 300 abuts against the first surface portion 15a, the outer periphery surface 350 of the tubular material 300 abuts against the abutment surface 37a, and the first outer periphery blade 31 and the second outer periphery blade 32 are abutted against the tubular material 300. With this, the tubular material 300 is rotated in the direction of arrow A (see FIG. 3). As a result, the end face 320 of the tubular material 300 is scraped by the end face blade 6, the first outer periphery portion 330 is scraped by the first outer periphery blade 31, and the second outer periphery portion 340 is scraped by the second outer periphery blade 32. 11B is a diagram showing the state after the tubular material 300 has been scraped by the scraper device 1. As shown in FIG. 11B, the first outer peripheral portion 330 scraped by the first outer peripheral blade 31 and the second outer peripheral portion 340 scraped by the second outer peripheral blade 32 have smaller outer diameters than the unprocessed portion 360. Therefore, even if the scraped pipe material 300 is inserted into the scraper device 1, the unprocessed portion 360 will come into contact with the contact surface 37a as shown in Figure 11B, and the first outer peripheral portion 330 will not come into contact with the first outer peripheral blade 31, and the second outer peripheral portion 340 will not come into contact with the second outer peripheral blade 32. This prevents the pipe material 300 from being scraped twice. Note that the pipe material 400 is also scraped in the same way as the pipe material 300.

[0059] (Outline of piping structure 500) Next, a piping structure 500 will be described, which is produced by scraping a pipe material 300 using the scraper device 1 described above and then fusing the pipe material 300 via an electrofusion joint 100.

[0060] Fig. 12 is a diagram showing an electrofusion joint 100 according to an embodiment of the present disclosure, and a tubing material 300 and a tubing material 400 that are connected by the electrofusion joint 100. Fig. 12 can also be considered an exploded view of a piping structure 500. The piping structure 500 includes, for example, the electrofusion joint 100, the tubing material 300, and the tubing material 400.

[0061] As shown in the figure, electrofusion joint 100 is fused to scraped pipe material 300 and pipe material 400, connecting pipe material 300 and pipe material 400. Note that pipe material 400 is the same as pipe material 300 and has been scraped in the same manner as pipe material 300. That is, end surface 420 of end portion 410 of pipe material 400 is scraped by end surface blade 6, first outer peripheral portion 430, which is a predetermined portion of outer peripheral surface 450 from end surface 420 along axial direction J, is scraped by first outer peripheral blade 31, and second outer peripheral portion 440, which is a predetermined portion of outer peripheral surface 450 spaced a predetermined distance from first outer peripheral portion 430 along axial direction J, is scraped by second outer peripheral blade 32. The unscraped portion of pipe material 400 between first outer peripheral portion 430 and second outer peripheral portion 440 is shown as unscraped portion 460.

[0062] Flow paths 300f, 400f with circular cross sections extend through the interior of tubing 300 and tubing 400. Flow path 100f with a circular cross section extends through the interior of electrofusion joint 100. When tubing 300 and 400 are connected by electrofusion joint 100, the axes of the flow paths of tubing 300, tubing 400, and electrofusion joint 100 are aligned on the same straight line.

[0063] The direction in which the axis of each of the flow paths of the electric fusion joint 100, the pipe material 300, and the pipe material 400 extends is referred to as the axial direction J. Furthermore, in the electric fusion joint 100, the pipe material 300, and the pipe material 400, the direction perpendicular to each axis and moving toward or away from each other is referred to as the radial direction K, and the direction rotating around each axis is referred to as the circumferential direction L.

[0064] The pipe material 300 moves relative to the electric fusion joint 100 in the direction of arrow J1 in the axial direction J and is connected to the electric fusion joint 100. Furthermore, the pipe material 400 moves relative to the electric fusion joint 100 in the direction of arrow J2 in the axial direction J and is connected to the electric fusion joint 100. The state in which the pipe material 300 and the pipe material 400 are fused and connected to the electric fusion joint 100 constitutes the piping structure 500.

[0065] (Electrofusion joint 100) FIG. 13 is a diagram showing the cross-sectional structure of the electrofusion joint 100. As shown in FIG.

[0066] As shown in FIGS. 12 and 13, the electrofusion joint 100 has a main body 120, socket heating portions 130 and 140, a stopper heating portion 150, and a connector attachment portion 160.

[0067] (Main body 120) Main body 120 is formed from a thermoplastic resin, and as shown in Fig. 13, has a tubular portion 121 and a stopper portion 122. Tubular portion 121 is cylindrical and has a fitting socket portion 123, a fitting socket portion 124, and a connecting portion 125. A pipe 300 is inserted into fitting socket portion 123. A pipe 400 is inserted into fitting socket portion 124.

[0068] The thermoplastic resin used in the main body 120 is not particularly limited, but one with a melting point of less than 230°C is preferred.

[0069] Figure 14 is a cross-sectional view showing the state in which tubing 300 is inserted into the inside of fitting socket 123 of electrofusion joint 100, and tubing 400 is inserted into the inside of fitting socket 124. Figure 14 does not show cross sections of tubing 300 and tubing 400, but only the cross section of electrofusion joint 100. Tubing 300 and tubing 400 have been scraped by the scraper device 1 described above. In this embodiment, the inner diameters of fitting socket 123 and fitting socket 124 are the same, but they may be different. If they are different, the outer diameter of the tubing is set to match the inner diameter of the fitting socket.

[0070] 13 , the connecting portion 125 is connected to the joint socket portion 123 and the joint socket portion 124, and connects the joint socket portion 123 and the joint socket portion 124. The connecting portion 125 is a portion that connects the joint socket portion 123 and the joint socket portion 124, and a stopper portion 122, which will be described later, is provided on the inside in the radial direction K.

[0071] (Stopper portion 122) 13, the stopper portion 122 is formed as a protrusion along the circumferential direction L on the inner surface 121a of the cylindrical portion 121 over the entire circumference. The stopper portion 122 also contains a thermoplastic resin, and is preferably formed from the same thermoplastic resin as that used for the cylindrical portion 121.

[0072] The stopper portion 122 is formed to protrude radially inward from the inner surface 121a of the cylindrical portion 121. The stopper portion 122 is disposed on the inner side of the connecting portion 125 of the cylindrical portion 121 in the radial direction K. The stopper portion 122 may be formed as a single member together with the cylindrical portion 121, or may be formed as a separate member from the cylindrical portion 121.

[0073] The stopper portion 122 has a first side surface 122a, a second side surface 122b, and a circumferential surface 122c, which is an end surface of the stopper portion 122 on the inner side in the radial direction.

[0074] The first side surface 122a is a side surface of the stopper portion 122 on the side of the joint socket portion 123. The first side surface 122a is formed approximately perpendicular to the axial direction J from the inner surface 121a of the cylindrical portion 121 toward the inside in the radial direction K.

[0075] The second side surface 122b is a side surface of the stopper portion 122 on the joint socket portion 124 side. The second side surface 122b is formed approximately perpendicular to the axial direction J from the inner surface 121a of the cylindrical portion 121 toward the inside in the radial direction K.

[0076] The peripheral surface 122c connects the radially inner end of the first side surface 122a to the radially inner end of the second side surface 122b. The peripheral surface 122c is formed substantially parallel to the inner surface 121a of the cylindrical portion 121.

[0077] 13, if an imaginary plane connecting the inner surface 121a of the fitting socket portion 123 and the inner surface 121a of the fitting socket portion 124 is defined as M3, the stopper portion 122 of the main body portion 120 is a portion that is inside the imaginary plane M3. Furthermore, if an imaginary plane extending the first side surface 122a in the radial direction K is defined as M1, and an imaginary plane extending the second side surface 122b in the radial direction K is defined as M2, the connecting portion 125 is a portion of the main body portion 120 that is surrounded by the imaginary planes M1, M2, and M3.

[0078] 14, when the pipe 300 is inserted into the inside of the fitting receptacle 123, the end face 320 of the pipe 300 comes into contact with the first side face 122a of the stopper portion 122, thereby restricting the insertion position of the end face 320. Note that the end face 320 coming into contact with the first side face 122a includes cases where the end face 320 comes into direct contact with the first side face 122a and cases where the end face 320 comes into indirect contact with the first side face 122a via a heating wire 151 (described later) of the stopper heat generating portion 150.

[0079] 14, when the pipe 400 is inserted into the inside of the fitting receptacle 124, the end face 420 of the pipe 400 comes into contact with the second side face 122b of the stopper portion 122, thereby restricting the insertion position of the end face 420. Note that the end face 420 coming into contact with the second side face 122b includes a case where the end face 420 comes into direct contact with the second side face 122b, and a case where the end face 420 comes into indirect contact with the second side face 122b via a heating wire 151 (described later) of the stopper heat generating portion 150.

[0080] (Receptacle heating parts 130, 140) 13, the socket heating parts 130, 140 are provided in the joint socket parts 123, 124. The socket heating part 130 has a heating wire 131 embedded in the inner surface 121a of the joint socket part 123, which is one end of the cylindrical part 121.

[0081] The heating wire 131 is arranged so as to be wound around the inner surface 121a in the circumferential direction two times. The heating wire 131 is arranged in the vicinity of the inner surface 121a. The heating wire 131 may be buried in the cylindrical portion 121 so that a part of the heating wire 131 is exposed on the flow path 100f side, or may be completely buried.

[0082] As shown in FIG. 13, the socket heating part 140 has a heating wire 141 embedded in the inner surface 121a of the joint socket part 124 which is the other end of the cylindrical part 121.

[0083] The heating wire 141 is arranged so as to be wound around the inner surface 121a in the circumferential direction two times. The heating wire 141 is arranged in the vicinity of the inner surface 121a. The heating wire 141 may be buried in the cylindrical portion 121 so that a part of the heating wire 141 is exposed on the flow path 100f side, or may be completely buried.

[0084] The heating wire 131 has, for example, a conductor 131a and an insulating coating 131b. The heating wire 141 has, for example, a conductor 141a and an insulating coating 141b. The conductors 131a and 141a can be made of, for example, nichrome wire, iron-chrome type 2 wire, iron-chrome type 1 wire, or nickel-chrome wire.

[0085] The insulating coatings 131b, 141b are provided to cover the periphery of the conductor. The melting point of the insulating coatings 131b, 141b is 230°C or higher. In this embodiment, it is preferable that the insulating coatings be set to a temperature that does not melt even at the temperature at which the thermoplastic resin melts (for example, in the case of polyethylene, the heating wire is heated to 220°C). The insulating coatings 131b, 141b can be made of, for example, a fluorine-based resin or an imide-based resin, but it is more preferable to make them of a polyimide-based resin. Note that the heating wires 131, 141 do not necessarily have the insulating coatings 131b, 141b.

[0086] Receptacle heating part 140 is provided symmetrically with respect to receptacle heating part 130 and stopper part 122. Receptacle heating part 130 is configured by being wound two times along axial direction J so that heating wire 131 contacts joint receptacle part 123. Receptacle heating part 140 is configured by being wound two times along axial direction A so that heating wire 141 contacts joint receptacle part 124. In this embodiment, heating wires 131, 141 are wound so as to contact each other in axial direction J, but they may also be wound so as to not contact each other and have a gap therebetween.

[0087] As shown in Fig. 13, socket heating portion 130 is disposed adjacent to stopper portion 122 in axial direction J. Also, socket heating portion 140 is disposed adjacent to stopper portion 122 in axial direction J. For example, as shown in Fig. 13, heating wire 131 is disposed so as to be in contact with imaginary plane M1 formed by extending first side surface 122a in radial direction K. Also, as shown in Fig. 13, heating wire 141 is disposed so as to be in contact with imaginary plane M2 formed by extending second side surface 122b in radial direction K.

[0088] In this way, the inlet heating parts 130, 140 are arranged in the axial direction J next to the stopper part 122 so as to be in contact with the imaginary surfaces M2, M3, but a predetermined gap may be provided between the inlet heating parts 130, 140 and the stopper part 122.

[0089] Furthermore, in each of the inlet heating parts 130, 140, the heating wires 131, 141 are wound around in contact with each other for two turns, but this is not limited to two turns. Furthermore, all or part of the wires do not have to be in contact with each other. Furthermore, there may be multiple portions where a predetermined number of wires are adjacent to each other.

[0090] Furthermore, although socket heating portion 130 and socket heating portion 140 are provided symmetrically on either side of stopper portion 122, this is not the only possible configuration. For example, heating wire 131 may be wound two times around joint socket portion 123, with stopper portion 122 in between, and heating wire 141 may be wound three times around joint socket portion 124, with stopper portion 122 in between.

[0091] (Stopper heating part 150) The stopper heating part 150 is provided in the stopper part 122. The stopper heating part 150 has a heating wire 151. The heating wire 151 is provided in the stopper part 122 so as to be wound in the circumferential direction L along the axial direction J. In this embodiment, the heating wire 151 is wound around the stopper part 122, for example, four times. In the stopper heating part 150 of this embodiment, adjacent heating wires 151 are all in contact with each other, but gaps may be provided.

[0092] The heating wire 151 is embedded in the stopper portion 122 so as to be in contact with the peripheral surface 122c of the stopper portion 122, but it may also be embedded in the stopper portion 122 so that a portion of it is exposed from the first side surface 122a, the second side surface 122b or the peripheral surface 122c to the flow path 100f side, or it may be embedded at a predetermined distance from the peripheral surface 122c of the stopper portion 122.

[0093] The heating wire 151 has a conductive wire 151a and an insulating coating 151b, as shown in Fig. 13. The conductive wire 151a may be made of, for example, a nichrome wire, an iron-chrome type 2 wire, an iron-chrome type 1 wire, or a nickel-chrome wire.

[0094] Insulating coating 151b is provided to cover the periphery of conductive wire 151a. Insulating coating 151b has a melting point of 230°C or higher. In this embodiment, it is preferable that the temperature is set to a value that does not melt even at the temperature at which thermoplastic resin melts (for example, in the case of polyethylene, the heating wire is heated to 220°C). Insulating coating 151b can be made of, for example, a fluorine-based resin or an imide-based resin, but it is more preferable to make it of a polyimide-based resin. Note that heating wire 151 does not necessarily have insulating coating 151b.

[0095] In this embodiment, in stopper heat generating portion 150, one heating wire 151 is wound four times so as to contact the adjacent wires, but this is not limited to this and may be three or fewer turns or five or more turns. Also, instead of being limited to one wire, two or more heating wires 151 may be wound to form stopper heat generating portion 150. Heating wire 151 may be wound so that all or part of it does not contact the adjacent wires.

[0096] (Connector mounting portion 160) As shown in FIG. 13 , the connector attachment portion 160 has two pins 161. The two pins 161 are provided so as to protrude radially outward from the outer surface 121d of the cylindrical portion 121. As shown in FIG. 13 , one of the two pins 161 is disposed near the end 121b of the cylindrical portion 121, and the other pin 161 is disposed near the end 121c. Although not shown, the two pins 161 are connected to the heating wires 131 and 141 of the socket heating portions 130 and 140 and the heating wire 151 of the stopper heating portion 150. When a connector of an electrofusion device is attached to the pin 161 and current is applied, the heating wires 131, 141, and 151 generate heat. In this embodiment, the heating wires 131, 141, and 151 are connected to each other and form a single heating wire.

[0097] <Jig 200> Next, a description will be given of a jig 200 used in the connection method of the embodiment according to the present disclosure. A tubular material 300, an electrofusion joint 100, and a tubular material 400 are arranged in the jig 200. Fig. 15 is a diagram showing the jig 200. Fig. 16 is a schematic plan view showing the jig 200. Fig. 17 is a diagram showing the tubular material 300, the electrofusion joint 100, and the tubular material 400 attached to the jig 200.

[0098] The jig 200 includes a first clamping portion 210, a second clamping portion 220, a shaft portion 230, a pressing portion 240, and a base 250.

[0099] (Base 250) The base 250 is a plate-shaped member and supports the first clamping portion 210, the second clamping portion 220, and the shaft portion 230, which are arranged on the upper surface side of the base 250. The base 250 also supports the pressing portion 240.

[0100] (First clamping portion 210) The first clamping portion 210 clamps and secures the pipe material 300. The first clamping portion 210 has a lower clamping portion 211, an upper clamping portion 212, a hinge portion 213, a fastening portion 214, and a bearing portion 215. The lower clamping portion 211 is a member having a semicircular recess 211a formed on its upper surface. In this embodiment, the lower clamping portion 211 is a roughly rectangular parallelepiped member having a semicircular recess formed on its upper surface.

[0101] The bearing portion 215 is provided in the lower clamp portion 211. The bearing portion 215 is inserted into a through hole formed in the lower clamp portion 211. The bearing portion 215 is arranged below the recessed portion 211a. The shaft portion 230, which will be described later, is inserted into the inside of the bearing portion 215. The axial direction of the bearing portion 215 is arranged parallel to the central axis of the recessed portion 211a. This allows the first clamp portion 210 to move along the shaft portion 230. When the pipe material 300, the pipe material 400, and the electrofusion joint 100 are placed in the jig, the axial direction of the bearing portion 215 is parallel to the axial direction J.

[0102] The upper clamping portion 212 is a member having a semicircular recess 212a formed therein. In this embodiment, the upper clamping portion 212 is a member having a roughly rectangular parallelepiped shape having the semicircular recess 212a formed on a predetermined surface thereof.

[0103] The upper clamping part 212 and the lower clamping part 211 can clamp the outer periphery of the pipe material 300 with the recesses 212a and 211a formed therein. When the pipe material 300 is clamped, the central axes of the recesses 212a and 211a roughly coincide. Furthermore, when the pipe material 300 is clamped, this central axis coincides with the axial direction J described above.

[0104] The hinge portion 213 rotatably connects the ends of the lower clamp portion 211 and the upper clamp portion 212. The upper clamp portion 212 is configured to be rotatable relative to the lower clamp portion 211 around the hinge portion 213. The upper clamp portion 212 is attached to the lower clamp portion 211 via the hinge portion 213 so that, when the upper clamp portion 212 rotates around the hinge portion 213, its recess 212a faces the recess 211a of the lower clamp portion 211.

[0105] With the lower clamp part 211 and the upper clamp part 212 spaced apart around the hinge part 213, the pipe material 300 is placed along the recess 211a of the lower clamp part 211. After that, the upper clamp part 212 rotates around the hinge part 213, and the pipe material 300 is placed so as to fit into the recess 212a.

[0106] The fastening portion 214 is a so-called snap lock. The fastening portion 214 has a lock body 214a and a protrusion 214b. The fastening portion 214 is provided on the opposite side of the hinge portion 213, across the recesses 211a, 212a of the lower clamp portion 211 and the upper clamp portion 212. The lock body 214a is disposed on the side surface of the lower clamp portion 211, and the protrusion 214b is disposed on the side surface of the upper clamp portion 212. The lock body 214a has a lever 214c and an annular portion 214d. With the upper clamp portion 212 rotated above the lower clamp portion 211, the annular portion 214d can be hooked onto the protrusion 214b and the lever 214c can be tilted downward, thereby fastening the upper clamp portion 212 to the lower clamp portion 211 in a closed state.

[0107] (Second clamping portion 220) The second clamping portion 220 clamps and fixes the pipe material 400. The second clamping portion 220 fixes the pipe material 400 so that the central axis of the pipe material 400 coincides with the central axis of the pipe material 300.

[0108] The second clamping portion 220 has a lower clamping portion 221, an upper clamping portion 222, a hinge portion 223, and a fastening portion 224. The lower clamping portion 221 is a member having a semicircular recess 221a formed on its upper surface. In this embodiment, the lower clamping portion 221 is a roughly rectangular parallelepiped member having a semicircular recess formed on its upper surface. The lower clamping portion 221 is fixed to the base 250 via a bracket 270.

[0109] The upper clamping portion 222 is a member having a semicircular recess 222a formed therein. In this embodiment, the upper clamping portion 222 is a member having a roughly rectangular parallelepiped shape having the semicircular recess 222a formed on a predetermined surface thereof.

[0110] The upper clamping part 222 and the lower clamping part 221 can clamp the outer periphery of the pipe material 400 with the recesses 222a and 221a formed therein. When the pipe material 400 is clamped, the central axes of the recesses 222a and 221a roughly coincide. Furthermore, when the pipe material 400 is clamped, this central axis coincides with the axial direction J described above.

[0111] The hinge portion 223 rotatably connects the ends of the lower clamp portion 221 and the upper clamp portion 222. The upper clamp portion 222 is configured to be rotatable relative to the lower clamp portion 221 around the hinge portion 223. The upper clamp portion 222 is attached to the lower clamp portion 221 via the hinge portion 223 so that, when the upper clamp portion 222 rotates around the hinge portion 223, its recess 222a faces the recess 221a of the lower clamp portion 221.

[0112] With the lower clamp part 221 and the upper clamp part 222 spaced apart around the hinge part 223, the pipe material 400 is placed along the recess 221a of the lower clamp part 221. After that, the upper clamp part 222 rotates around the hinge part 223, and the pipe material 400 is placed so as to fit into the recess 222a.

[0113] The fastening portion 224 is a so-called snap lock. The fastening portion 224 has a lock body 224a and a protrusion 224b. The fastening portion 224 is provided on the opposite side of the hinge portion 223, across the recesses 221a, 222a of the lower clamp portion 221 and the upper clamp portion 222. The lock body 224a is disposed on the side surface of the lower clamp portion 221, and the protrusion 224b is disposed on the side surface of the upper clamp portion 222. The lock body 224a has a lever 224c and an annular portion 224d. With the upper clamp portion 222 rotated above the lower clamp portion 221, the annular portion 224d can be hooked onto the protrusion 224b and the lever 224c can be tilted downward, thereby fastening the upper clamp portion 222 to the lower clamp portion 221 in a closed state.

[0114] With the pipe material 300 and the pipe material 400 inserted into the electric fusion joint 100, the pipe material 300 can be clamped with the first clamping part 210 and the pipe material 400 can be clamped with the second clamping part 220, thereby placing the pipe material 300, the pipe material 400 and the electric fusion joint 100 in the jig 200.

[0115] (shaft 230) The shaft portion 230 is supported by the base 250. The shaft portion 230 is arranged parallel to the central axes of the recesses 211a and 212a of the first clamp portion 210. The shaft portion 230 is arranged parallel to the central axes of the recesses 221a and 222a of the second clamp portion 220. The shaft portion 230 is also arranged parallel to the central axes of the pipe material 300 fixed to the first clamp portion 210 and the pipe material 400 fixed to the second clamp portion 220. The shaft portion 230 is arranged along the axial direction J described above.

[0116] The shaft portion 230 extends from the second clamp portion 220 toward the first clamp portion 210. The first clamp portion 210 is attached to the shaft portion 230 so as to be movable along the shaft portion 230. The shaft portion 230 is arranged from the lower clamp portion 221 to the lower clamp portion 211. A bearing portion 215 is arranged below the recessed portion 211a of the lower clamp portion 211 of the first clamp portion 210, and the shaft portion 230 is inserted into the bearing portion 215.

[0117] (Pressing portion 240) The pressing portion 240 presses the first clamp portion 210 toward the second clamp portion 220 along the shaft portion 230. The pressing portion 240 has, for example, an electric cylinder 241 and a connecting portion 242, as shown in FIG.

[0118] 16, the electric cylinder 241 is disposed on the side of the base 250. The electric cylinder 241 has a motor (not shown), a rod 243, and a cylinder 244. The rod 243 is disposed parallel to the axial direction J. The rod 243 is movable relative to the cylinder 244 in a direction parallel to the axial direction J by being driven by the motor.

[0119] The connecting portion 242 connects the rod 243 and the lower clamp portion 211. The connecting portion 242 is a substantially plate-shaped member. The connecting portion 242 is arranged in a direction (width direction) perpendicular to the axial direction J in a plan view. One end 242a of the connecting portion 242 in the width direction is fixed to the rod 243. The other end 242b of the connecting portion 242 in the width direction is passed through the shaft portion 230. The end 242b is fixed to the lower clamp portion 211.

[0120] When the rod 243 moves toward the cylinder 244, the first clamp portion 210 including the lower clamp portion 211 moves along the shaft portion 230 toward the second clamp portion 220 (in the J1 direction).

[0121] As shown in Figure 17, when the pipe material 300, the pipe material 400, and the electric fusion joint 100 are placed in the jig 200, a load is applied to the first clamp portion 210 by the pressing portion 240, so that the end face 320 of the pipe material 300 and the end face 420 of the pipe material 400 are pressed against the stopper portion 122.

[0122] <Connection method> Next, a description will be given of a connection method using the above-described jig 200. Fig. 18 is a flow chart showing the connection method of this embodiment.

[0123] First, in step S1 (an example of a scraping step), the end 310 of the tubular material 300 is inserted into the scraper device 1 through the opening 3a, and the tubular material 300 is rotated as shown by arrow A in Figure 4 with the end face 320 in contact with the first surface portion 15a. As a result, the end face 320, the first outer peripheral portion 330, and the second outer peripheral portion 340 are scraped, as shown in Figure 5(b). Similarly, the end 410 of the tubular material 400 is also inserted into the scraper device 1, and the end face 420, the first outer peripheral portion 430, and the second outer peripheral portion 440 are scraped.

[0124] Next, in step S2 (an example of an insertion step), the tubing 300 and the tubing 400 are inserted into the electrofusion joint 100. As shown in Fig. 14 , the tubing 300 is inserted into the inside of the joint socket 123 of the electrofusion joint 100 until the relative movement of the end face 320 of the tubing 300 is restricted by the stopper portion 122. Next, the tubing 400 is inserted into the inside of the joint socket 124 of the electrofusion joint 100 until the relative movement of the end face 420 of the tubing 400 is restricted by the stopper portion 122.

[0125] In this state, in step S3 (an example of an arrangement process), as shown in Figure 17, the pipe material 300 is clamped and fixed by the first clamp portion 210, and the pipe material 400 is clamped and fixed by the second clamp portion 220, and the pipe material 300, the electric fusion joint 100 and the pipe material 400 are arranged in the jig 200.

[0126] 14 and 17, the second outer circumferential portion 340 of the tubing 300 is formed in a position that straddles the end 121b of the fitting socket 123. The second outer circumferential portion 440 of the tubing 400 is formed in a position that straddles the end 121c of the fitting socket 124. FIG. 19(a) is a diagram showing the vicinity of the first clamp section 210. As shown in FIG. 19(a), the second outer circumferential portion 340 of the tubing 300 is exposed from the end 121b of the electrofusion joint 100. Similarly, the second outer circumferential portion 440 of the tubing 400 is also exposed from the end 121c of the electrofusion joint 100.

[0127] In step S4 (an example of a confirmation step), the length of the second outer circumferential portion 340 along the axial direction J that is exposed from the electrofusion joint 100 is measured. The length d3 from the end 121b of the electrofusion joint 100 to the exposed end 340a of the second outer circumferential portion 340 in FIG. 19(a) is measured. The portion of the second outer circumferential portion 440 of the tubing 400 that is exposed from the electrofusion joint 100 is similarly measured. The end 440a of the second outer circumferential portion 440 of the tubing 400 opposite the electrofusion joint 100 is shown in FIG.

[0128] Next, in step S5 (an example of a heating step), connectors of an electric fusion device are attached to the two pins 161 of the connector attachment portion 160, and electricity is applied for a predetermined time. This application of electricity causes the heating wires 131, 141, 151 to heat, melting the resin around the socket heating portions 130, 140 and the stopper heating portion 150, the end face 320 and first outer circumferential portion 330 of the pipe material 300, and the end face 420 and first outer circumferential portion 430 of the pipe material 400, and causing them to adhere to each other. The temperature of the heating wires during application of electricity may be any temperature that melts the main body portion 120; for example, heating is performed at 230°C. In the case of polyolefin, 220°C or less is preferable.

[0129] Furthermore, the scraped end surface 320 of the pipe material 300 abuts against the stopper portion 122, the first outer peripheral portion 330 is positioned opposite the receiving port heating portion 130, and the scraped end surface 420 of the pipe material 400 abuts against the stopper portion 122, and the first outer peripheral portion 430 is positioned opposite the receiving port heating portion 140, so that fusion is performed well.

[0130] Next, in step S6 (an example of a pressing step), electric cylinder 241 is driven in a heated state to move rod 243 toward J1, thereby applying a load to first clamp portion 210 toward second clamp portion 220. By applying a load from first clamp portion 210 toward second clamp portion 220, end face 320 of pipe material 300 is pressed against first side surface 122a of stopper portion 122, and end face 420 of pipe material 400 is pressed against second side surface 122b of stopper portion 122. As an example, a load of approximately 24 N·m can be applied.

[0131] Next, after a predetermined time has elapsed, in step S7 (an example of a cooling step), cooling is carried out for a predetermined time of the molten pipe material 300, the electrofusion joint 100, and the pipe material 400. Note that the pressing may be continued until the cooling in step S7 is completed, or may be stopped when the heating is stopped.

[0132] Next, in step S8 (an example of an evaluation step), the length d4 along the axial direction J of the second outer circumferential portion 340 exposed from the electrofusion joint 100 is measured, and an evaluation is made to determine whether the fusion is good or bad. FIG. 19(b) is a diagram showing the vicinity of the first clamp section 210 in a fused state from the state of FIG. 19(a). The length d4 from the end 121b of the electrofusion joint 100 to the exposed end 440a of the second outer circumferential portion 340 in FIG. 19(b) is measured. The portion of the second outer circumferential portion 440 of the tubing 400 exposed from the electrofusion joint 100 is also measured in a similar manner.

[0133] Figure 20 is a cross-sectional view showing the state in which tubing 300, electrofusion joint 100, and tubing 400 have melted and been connected. As shown in Figure 20, stopper portion 122 melts and is pressed and narrowed by tubing materials 300 and 400, filling the gap between tubing materials 300 and 400 and forming a bead R. At this time, due to the pressure of pressing portion 240, tubing materials 300 and 400 move toward the inside of electrofusion joint 100 while crushing stopper portion 122, and a bead R is formed according to the amount of movement.

[0134] Therefore, by measuring the length of the crushed end faces 320, 420 of the pipe materials 300, 400, it is possible to evaluate whether the fusion was good or bad. The difference between the length d4 measured in step S8 and the length d3 measured in step S4 is calculated, and if this difference is equal to or greater than a predetermined amount, it can be determined that the fusion was good. As an example, if d3 is 4 mm and d4 is 1 mm, the fusion shrinks by 3 mm compared to before fusion, and if this 3 mm is equal to or greater than a threshold value, it can be determined that the fusion was good. If it is determined that the fusion is not satisfactory, the pipes 300, 400 and the electrofusion joint 100 may be prepared again and the connection work may be performed again, or heating and pressing may be performed again.

[0135] 19(b), it is preferable that the second outer circumferential portions 340, 440 are formed in a range that remains exposed from the electrofusion joint 100 even after fusion. With the scraper device 1 of this embodiment, the end face 320 of the end portion 310 of the tubular material 300, the first outer circumferential portion 330, and the second outer circumferential portion 340 are simultaneously scraped, so that by visually checking the scraped traces of the second outer circumferential portion 340, it can be confirmed that the scraping process before fusion was carried out reliably. The same applies to the tubular material 400.

[0136] <Ultrapure water application for piping structure 500> The piping structure 500 according to the embodiment of the present disclosure can be used, for example, to transport ultrapure water. Specifically, the piping structure 500 for ultrapure water according to the embodiment of the present disclosure can be used as piping within an ultrapure water production apparatus, piping for transporting ultrapure water from an ultrapure water production apparatus to a use point, piping for returning ultrapure water from a use point, etc.

[0137] Ultrapure water is water with extremely high purity, and is suitable for use in cleaning electronic devices such as semiconductor devices. There are many indices for expressing the grade of ultrapure water, but in this embodiment, the electrical resistivity of ultrapure water is 18.2 MΩ cm or more, and the TOC is 50 ppb or less.

[0138] The piping structure 500 according to the embodiment of the present disclosure is preferably a water piping for nuclear power generation, which requires particularly strict water quality for ultrapure water, or a piping for transporting ultrapure water used in wet processing steps such as cleaning in the manufacturing process of pharmaceuticals, semiconductor devices, or liquid crystals, more preferably semiconductor devices. The semiconductor devices are preferably those with a high degree of integration, and more preferably, those used in the manufacturing process of semiconductor devices with a minimum line width of 65 nm or less. Standards for the quality of ultrapure water used in semiconductor manufacturing include, for example, SEMI F75.

[0139] Furthermore, the piping structure 500 according to the embodiment of the present disclosure has a polyethylene resin layer, which makes it easy to work with. For example, fusion work such as electrofusion (EF) bonding can be easily performed at a relatively low temperature.

[0140] <Features> (1) The connection method according to this embodiment is a method for connecting tubing materials 300, 400 and an electrofusion joint 100, and includes step S1 (an example of a scraping step), step S2 (an example of an insertion step), step S5 (an example of a heating step), step S6 (an example of a pressing step), and step S8 (an example of an evaluation step). In step S1, a predetermined portion of the outer circumferential surface 350, 450 of the tubing material 300, 400 is scraped so that at least a portion of the outer circumferential surface 350, 450 is exposed from the electrofusion joint 100 when the tubing material 300, 400 is inserted into the electrofusion joint 100, thereby creating a second outer circumferential portion 340, 440 (an example of an indicator portion) for evaluating the connection state. In step S2, the tubing material 300, 400 is inserted into the electrofusion joint 100. In step S5, after step S2, electricity is applied to the electrofusion joint 100 to heat it. In step S6, after step S2, the tubing 300, 400 is pressed against the electrofusion joint 100. In step S8, after steps S5 and S6 are started, the positional relationship of the second outer circumferential portions 340, 440 with respect to the electrofusion joint 100 is confirmed, and the connection state is evaluated by comparing the positional relationship of the second outer circumferential portions 340, 440 with respect to the electrofusion joint 100 before step S5.

[0141] While heating the electrofusion joint 100, the tubular materials 300, 400 are pressed against the electrofusion joint 100, thereby forcing the tubular materials 300, 400 into the inside of the electrofusion joint 100 and forming a bead R in the fused portion (see FIG. 20). If the height of the bead R is greater than a predetermined value, the fusion connection can be evaluated as being good, and the height of the bead R increases the more the tubular materials 300, 400 are pressed into the inside of the electrofusion joint.

[0142] Therefore, by checking the positional relationship between the electrofusion joint 100 and the second outer circumferential portions 340, 440 before and after the start of steps S5 and S6, the connection between the tubing 300, 400 and the electrofusion joint 100 can be evaluated.

[0143] For example, by using a pipe material or a joint member in which the outer peripheral surfaces 350, 450 and the inside are different colors, the color of the second outer peripheral portions 340, 440 is different from the other portions, making it easier to visually confirm the position of the second outer peripheral portions 340, 440. Furthermore, even if the color of the scraped second outer peripheral portions 340, 440 is the same as the other portions, the position of the second outer peripheral portions 340, 440 can be confirmed by the step that occurs between the second outer peripheral portions 340, 440 and the other portions.

[0144] (2) In the connection method according to this embodiment, the positional relationship includes the length from the ends 121b, 121c of the electrofusion joint 100 to the ends of the second outer periphery portions 340, 440. In step S8, the length from the ends 121b, 121c of the electrofusion joint 100 to the ends of the second outer periphery portions 340, 440 is measured, and if the amount by which the measured length has shrunk from the length from the ends 121b, 121c of the electrofusion joint 100 to the ends of the second outer periphery portions 340, 440 before step S5 is greater than a predetermined amount, the connection condition is evaluated as good.

[0145] This allows the connection to be evaluated based on the amount by which the length from the ends 121b, 121c of the electrofusion joint 100 to the ends of the second outer periphery portions 340, 440 has shortened from before the start of heating to after the start of heating.

[0146] (3) In the connecting method according to this embodiment, in step S8, the second outer circumferential portions 340, 440 are arranged so as to straddle the ends 121b, 121c of the electrofusion joint 100. The positional relationship includes the length from the ends 121b, 121c of the electrofusion joint 100 to the ends 340a, 440a of the second outer circumferential portions 340, 440 on the side opposite to the electrofusion joint 100.

[0147] This allows the connection to be evaluated based on the amount by which the length from the ends 121b, 121c of the electric fusion joint 100 to the ends 340a, 440a of the second outer peripheral portions 340, 440 opposite the electric fusion joint 100 has shortened from before heating began to after heating began.

[0148] (4) The connection method according to this embodiment further includes step S4 (an example of a confirmation step). Step S4 is performed after step S2 and before step S5, and confirms the positional relationship of the second outer circumferential portions 340, 440 with respect to the electrofusion joint 100.

[0149] This makes it possible to accurately grasp the positional relationship of the second outer periphery portions 340, 440 with respect to the electrofusion joint 100 before heating begins, and to perform precise evaluation of the connection.

[0150] (5) In the connecting method according to this embodiment, the electrofusion joint 100 has joint socket portions 123, 124 and socket heating portions 130, 140. The pipes 300, 400 are inserted into the joint socket portions 123, 124. The socket heating portions 130, 140 are disposed in the joint socket portions 123, 124. In step S1, the first outer peripheral portions 330, 430 (an example of an end portion) of the outer peripheral surfaces 350, 450 within a predetermined range from the end faces 320, 420 of the pipes 300, 400 are cut, as well as the second outer peripheral portions 340, 440. In step S5, the first outer peripheral portions 330, 430 of the outer peripheral surfaces 350, 450 are disposed opposite the socket heating portions 130, 140.

[0151] In this way, the first outer peripheral portions 330, 430 and the second outer peripheral portions 340, 440 of the outer peripheral surfaces 350, 450, which are the fused portions with the fitting socket portions 123, 124, are formed simultaneously by scraping. Therefore, by checking the second outer peripheral portions 340, 440 after the connection is completed, it is possible to confirm that scraping has been performed on the fused portions.

[0152] (6) In the connecting method according to this embodiment, the electrofusion joint 100 has a tubular portion 121, a stopper portion 122, and a stopper heating portion 150. The tubular portion 121 includes joint socket portions 123, 124. The stopper portion 122 is provided on the inner surface 121a of the tubular portion 121 so as to protrude inward, and is pressed against the end faces 320, 420 of the tubular members 300, 400 inserted into the joint socket portions 123, 124. The stopper heating portion 150 is disposed on the stopper portion 122. In step S1, the end faces 320, 420 of the tubular members 300, 400 are cut simultaneously with the second outer peripheral portions 340, 440 and the first outer peripheral portions 330, 430, which are end portions of the outer peripheral surface 350.

[0153] In this way, the end faces 320, 420, which are the fused portions with the stopper portion 122, the first outer peripheral portions 330, 430, which are the end portions of the outer peripheral surface 350, which are the fused portions with the fitting receptacle portions 123, 124, and the second outer peripheral portions 340, 440 are formed simultaneously by scraping. Therefore, by checking the second outer peripheral portions 340, 440 after the connection is completed, it is possible to confirm that the scraping process has been carried out on the fused portions.

[0154] <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 are possible without departing from the gist of the invention.

[0155] (A) In the above embodiment, as shown in Fig. 14, the second outer circumferential portion 340 is formed so as to straddle the end 121b of the electrofusion joint 100, but this is not limiting. For example, the entire second outer circumferential portion 340 may be exposed from the electrofusion joint 100 when the end face 320 of the tubular material 300 is abutted against the stopper portion 122. Fig. 21(a) is a diagram showing the electrofusion joint 100, tubular material 300, and tubular material 400 in which the entire second outer circumferential portions 340, 440 are exposed from the electrofusion joint 100.

[0156] In this case, not only end 340a of second outer circumferential portion 340 opposite electrofusion joint 100, but also end 340b on the electrofusion joint 100 side is exposed. Similarly, in tubing 400, ends 440a and 440b of second outer circumferential portion 440 are exposed from electrofusion joint 100. FIG. 21(b) shows the electrofusion joint 100, tubing 300, and tubing 400 after steps S5 and S6. As shown in FIG. 21(b), after fusion, second outer circumferential portion 340 approaches electrofusion joint 100, and second outer circumferential portion 440 approaches electrofusion joint 100. Therefore, the connection can be evaluated from the distance at which second outer circumferential portions 340, 440 approach electrofusion joint 100. Either the distance from the electrofusion joint 100 to the ends 340a, 440a of the second outer periphery portions 340, 440 or the distance from the electrofusion joint 100 to the ends 340b, 440b of the second outer periphery portions 340, 440 may be used for connection evaluation.

[0157] In this way, the connection can be evaluated based on the positional relationship of the second outer circumferential portions 340, 440 with respect to the electrofusion joint 100 before and after fusion.

[0158] (B) In the above embodiment, in step S4, the length d3 from the ends 121b, 121c of the electrofusion joint 100 to the ends 340a, 440a of the second outer periphery portions 340, 440 before heating and pressurization is measured, but step S4 does not have to be provided. This is because the dimensions of the electrofusion joint 100 and the positions of the second outer periphery portions 340, 440 from the end faces 320, 420 are determined, so d3 can be calculated in advance.

[0159] (C) In the above embodiment, the electrofusion joint 100 is provided with a stopper portion 122, but the stopper portion 122 need not be provided. In this case, the first outer circumferential portion 330 of the pipe 300 and the resin around the socket heating portion 130 are fused together, and the first outer circumferential portion 430 of the pipe 400 and the resin around the socket heating portion 130 are fused together. In addition, the end faces 320, 420 do not need to be scraped, and the scraper device 1 does not need to be provided with an end face blade 6.

[0160] (D) In the scraper device 1 of the above embodiment, an end face blade 6 is provided, but when an electrofusion joint without a stopper portion is used, the end faces 320, 420 do not need to be scraped, and the end face blade 6 does not need to be provided.

[0161] (E) In the above embodiment, after the heating process in step S5 and the pressing process in step S6 are completed and the cooling process in step S7 is completed, d4 ​​is measured in step S8, but this is not limited to this. d4 may be measured after the start of steps S5 and S6 or before their completion to confirm that it has moved a predetermined amount or more from d3. Also, steps S5 and S6 may be started in either order.

[0162] (F) In the above embodiment, the pipe materials 300, 400 are used as the objects to be fused with the electrofusion joint 100, but this is not limited to pipe materials and may be joint members.

[0163] (G) In the above embodiment, the flow paths of the electrofusion joint 100 are all formed straight, but they may also be elbow joints in which the flow paths are curved.

[0164] (H) In the above embodiment, heating wire 131 of receptacle heating portion 130, heating wire 141 of receptacle heating portion 140, and heating wire 151 of stopper heating portion 150 are each formed from a single heating wire, but this is not a limitation and separate heating wires may be connected. Also, while all heating wires 131, 141, and 151 are provided with an insulating coating, this is not a limitation. However, it is preferable that at least heating wire 151 be provided with an insulating coating. This is because heating wires 151 are likely to come into contact with each other due to pressure applied by pipe material 300 and pipe material 400.

[0165] (I) In the above embodiment, the pipe materials 300 and 400 are used as an example of a pipe, but the pipe is not limited to this and may be a pipe made of resin, such as a metal-reinforced composite pipe having a metal reinforcing layer.

[0166] (J) In the above embodiment, the receptacle heating part 130 and the receptacle heating part 140 are heated simultaneously, but if a connector connection part is provided for each of the receptacle heating part 130 and the receptacle heating part 140, it is also possible to heat one of the receptacle heating part 130 and the receptacle heating part 140 before heating the other.

[0167] (K) In the above embodiment, a motor, a cylinder, or the like is used as a pressing unit that applies a load to the first clamp unit 210, but a spring may also be used. When a motor or a cylinder is used to apply a load as in the present embodiment, it may be controlled in conjunction with the electrofusion device. For example, the motor or cylinder may be controlled in accordance with the elapsed heating time of the electrofusion device so that a load equal to or greater than a predetermined value is maintained according to a preset program. [Explanation of symbols]

[0168] 100: Electric fusion joint 300: Tube material 340: 2nd outer peripheral part 350: Outer surface

Claims

1. A method for connecting a pipe material or a joint member to an electric fusion joint, comprising: a scraping step of scraping a predetermined portion of the outer peripheral surface of the tubular material or the joint member so that at least a part of the portion is exposed from the electrofusion joint when the tubular material or the joint member is inserted into the electrofusion joint, thereby creating an indicator portion for evaluating the connection state; an insertion step of inserting the pipe material or the joint member into the electric fusion joint; a heating step of applying electricity to the electric fusion joint to heat it after the inserting step; a pressing step of pressing the tubing or the joint member against the electrofusion joint or against another tubing or joint member inserted into the electrofusion joint on the opposite side after the inserting step; an evaluation step of checking a positional relationship of the indicator portion with respect to the electrofusion joint after starting the heating step and the pressing step, and evaluating a connection state by comparing the positional relationship of the indicator portion with the positional relationship of the electrofusion joint before the heating step, the positional relationship includes a length from an end of the electrofusion joint to an end of the indicator portion, In the evaluation step, a length from an end of the electrofusion joint to an end of the indicator portion is measured, and the connection state is evaluated as good if the amount of shrinkage of the measured length from the length from the end of the electrofusion joint to the end of the indicator portion before the heating step is greater than a predetermined amount. How to connect.

2. the indicator portion is arranged to straddle an end of the electrofusion joint in the evaluation step, the positional relationship includes a length from an end of the electrofusion joint to an end of the indicator portion opposite to the electrofusion joint; The connection method according to claim 1 .

3. The method further includes a confirmation step of confirming a positional relationship of the indicator portion with respect to the electrofusion joint after the insertion step and before the heating step.

3. The connection method according to claim 1 or 2.

4. The electric fusion joint is a joint socket portion into which the pipe material or the joint member is inserted; a socket heating portion disposed in the joint socket portion, In the scraping step, an end portion of the outer peripheral surface within a predetermined range from the end face of the pipe material or the coupling member is scraped at the same time as the predetermined portion is scraped, In the heating step, the end portion of the outer circumferential surface is disposed opposite the receiving port heating portion.

3. The connection method according to claim 1 or 2.

5. The electric fusion joint is a cylindrical portion including the fitting socket portion; a stopper portion provided on the inner surface of the cylindrical portion so as to protrude inward, against which the end face of the pipe or the coupling member inserted into the coupling socket portion is pressed; a stopper heating portion disposed in the stopper portion, The scraping step scrapes the end surface of the pipe material or the joint member at the same time as scraping the predetermined portion and the end portion of the outer circumferential surface. The connection method according to claim 4.

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