Clamp and Electric Fusion Joint Unit

Abstract

To provide a clamp capable of securing an alignment performance between resin pipes even in a case where a joint is heavy, while suppressing cost.SOLUTION: The present invention relates to a resin clamp 100 holding a resin pipe P and an electric fusion joint F to which the resin pipe P is connected by heat fusion. The clamp comprises: fastening belt parts 10 including a pipe fastening belt portion 11 in a belt shape whose diameter can be reduced so as to hold the resin pipe P in a state where the resin pipe P is disposed inside of the electric fusion joint F, and a joint fastening belt portion 12 in a belt shape whose diameter can be reduced so as to hold the electric fusion joint F; and engage parts 20 which are engaged with each other in a circumferential direction circulating around the fastening belt parts 10 in an axial direction, thereby maintaining a diameter reduced state of the fastening belt parts 10. The engage parts 20 include a pipe-side engage portion 21 provided in the pipe fastening belt portion 11 and a joint-side engage portion 22 provided in the joint fastening belt portion 12. In the engage parts 20, engage teeth which can be engaged with each other are formed, and the joint fastening belt portion 12 and the pipe fastening belt portion 11 are coupled in the axial direction by a coupling part 30.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present invention relates to a clamp and an electric fusion joint unit.

Background Art

[0002] Conventionally, an electric fusion joint in which resin pipes made of a thermoplastic resin are connected by heat fusion is known. When an electric current is passed through a power supply terminal with a resin pipe inserted inside a cylindrical electric fusion joint, a heating wire provided inside the electric fusion joint generates heat. Due to this heat, the outer peripheral surface of the resin pipe is melted and fused to the inner peripheral surface of the electric fusion joint. In the above-described connection operation, during heat fusion, the electric fusion joint and the resin pipe may be displaced. To prevent this, a structure is disclosed in which the resin pipe is held by a resin clamp attached to the power supply terminal of the electric fusion joint during cooling in heat fusion (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As the amount of displacement allowed for the electric fusion joint and the resin pipe, for example, it is required that the relative angle between the central axis of the electric fusion joint and the central axis of the resin pipe is 3° or less. Also, it is required that the amount of the resin pipe coming off from the electric fusion joint is within 1 mm. However, in the conventional clamp, the tightening member that holds the pipe and the holding part that holds the power supply terminal are only partially integrated. For this reason, although it is strong against pulling out in the pipe axis direction, there is a problem that the centering performance between resin pipes is weak, especially when fusing medium-diameter and large-diameter resin pipes with a heavy joint weight.

[0005] The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a clamp that can ensure the centering performance between resin pipes even in the case of medium and large diameters with a heavy joint weight while suppressing costs with an inexpensive configuration.

Means for Solving the Problems

[0006] In order to solve the above problems, the present invention proposes the following means. The clamp according to the present invention is a resin clamp that holds a resin pipe made of a thermoplastic resin and an electric fusion joint to which the resin pipe is connected by heat fusion. In a state where the resin pipe is disposed inside the electric fusion joint, a belt-shaped pipe tightening band portion that can be reduced in diameter so as to hold the resin pipe, and a belt-shaped joint tightening band portion that can be reduced in diameter so as to hold the electric fusion joint, a tightening band portion including, and an engaging portion that maintains the reduced diameter state of the tightening band portion by engaging with each other in the circumferential direction that circulates around the axial direction of the tightening band portion. The engaging portion includes a pipe-side engaging portion provided on the pipe tightening band portion and a joint-side engaging portion provided on the joint tightening band portion. Engaging teeth that can engage with each other are formed on the engaging portion, and the joint tightening band portion and the pipe tightening band portion are connected in the axial direction by a connecting portion.

[0007] According to this invention, the joint tightening band portion and the pipe tightening band portion are connected in the axial direction by a connecting portion. That is, the pipe tightening band portion and the joint tightening band portion are integrally provided around the resin pipe and the electric fusion joint. Thereby, not only the resin pipe but also the electric fusion joint can be held simultaneously depending on the shape of the clamp. Therefore, it is possible to prevent a shift or an angle from occurring between the resin pipe and the joint. As a result, it becomes possible to prevent an angle from occurring between the resin pipes inserted into the electric fusion joint. Therefore, the centering performance between the resin pipes can be improved.

[0008] Furthermore, since the clamp according to the present invention does not require a special material or the like, it can be configured at low cost. Therefore, even if it is mass-produced, there is no impact on the cost, so that work can be efficiently performed at a plurality of locations.

[0009] Further, the engaging portion may be provided at an end portion in the circumferential direction of the tightening band portion, and the end portion of the joint tightening band portion and the end portion of the pipe tightening band portion are not connected by the connecting portion, and the pipe-side engaging portion and the joint-side engaging portion are independent of each other.

[0010] According to this invention, the pipe-side engaging portion and the joint-side engaging portion are independent of each other. Thereby, while maintaining the integrality of the pipe tightening band portion and the joint tightening band portion, the engaging portion of the pipe tightening band portion and the engaging portion of the joint tightening band portion can be independently moved. Therefore, since it is not necessary to simultaneously reduce the diameters of the pipe tightening band portion and the joint tightening band portion, the work can be facilitated.

[0011] Further, the circumferential length of the joint tightening band portion may be longer than the circumferential length of the pipe tightening band portion.

[0012] According to this invention, the circumferential length of the joint tightening band portion is longer than the circumferential length of the pipe tightening band portion. That is, the outer diameter that the joint tightening band portion can hold is larger than the outer diameter that the pipe tightening band portion can hold. Therefore, a resin pipe and an electric fusion joint having different outer diameters from each other can be held by one clamp.

[0013] Further, the axial length of the joint tightening band portion may be longer than the axial length of the pipe tightening band portion.

[0014] According to this invention, the axial length of the joint tightening band portion is longer than the axial length of the pipe tightening band portion. Here, the electric fusion joint is relatively heavy with respect to the resin pipe. On the other hand, since the axial length of the joint tightening band portion is longer than the axial length of the pipe tightening band portion, the electric fusion joint can be more reliably held by the joint tightening band portion.

[0015] Further, the pipe-side engaging portion and the joint-side engaging portion may be separated from each other in the radial direction of the resin pipe.

[0016] According to the present invention, the pipe-side engaging portion and the joint-side engaging portion are separated from each other in the radial direction of the resin pipe. Here, if the pipe-side engaging portion and the joint-side engaging portion are at the same position in the radial direction, the diameter reduction of the pipe tightening band portion and the diameter reduction of the joint tightening band portion may be simultaneously performed by a tool or hands or the like. As a result, there is a possibility that the above-described diameter reduction may not be sufficiently performed. On the other hand, since the pipe-side engaging portion and the joint-side engaging portion are separated from each other in the radial direction, it is possible to avoid the simultaneous diameter reduction of the pipe tightening band portion and the joint tightening band portion. Therefore, the above-described problem can be prevented from occurring.

[0017] Further, at least one protrusion may be provided on the inner peripheral surfaces of the pipe tightening band portion and the joint tightening band portion.

[0018] According to the present invention, at least one protrusion is provided on the inner peripheral surfaces of the pipe tightening band portion and the joint tightening band portion. That is, when the pipe tightening band portion and the joint tightening band portion are reduced in diameter, only the protrusions come into contact with the resin pipe and the electric fusion joint, respectively. Therefore, by concentrating the tightening force by the tightening band portion on the protrusions, the holding force by the tightening band portion can be improved.

[0019] Further, the joint tightening band portion may be provided with a notch corresponding to the shape of the electric fusion joint.

[0020] According to the present invention, the joint tightening band portion is provided with a notch corresponding to the shape of the electric fusion joint. Here, near the end of the electric fusion joint, there may be provided a power supply terminal or an indicator. By providing a notch corresponding to such a shape, the clamp can be attached without interfering with the electric fusion joint.

[0021] Further, at least one insertion confirmation port for confirming the insertion state of the resin tube into the electric fusion joint may be provided in the connecting portion.

[0022] According to the present invention, an insertion confirmation port is provided in the connecting portion. Thereby, before starting the fusion operation by the electric fusion joint, it is possible to visually confirm that the resin tube is inserted into the electric fusion joint.

[0023] Further, the clamping band portion may be divided in the circumferential direction, and an assembling portion for assembling the divided clamping band portions to each other may be provided at the divided portion.

[0024] According to the present invention, the clamping band portion is divided in the circumferential direction. Here, when the clamping band portion is not divided, when aligning with the electric fusion joint, it is necessary to move the clamp along the axial direction of the resin tube in a state where the clamp is inserted into the resin tube. At this time, if the length of the resin tube is short, it may not be possible to move the clamp sufficiently. On the other hand, since the clamp is divided, without moving it over the resin tube, after bringing the divided clamping band portions closer to the resin tube from the outside in the radial direction, the engaging portion may be engaged and the assembling portion may be assembled, and the clamp can be directly attached to the electric fusion joint.

[0025] Further, the electric fusion joint unit according to the present invention includes an electric fusion joint that connects the resin tubes by heat fusion and the clamp.

Advantages of the Invention

[0026] According to the present invention, it is possible to provide a clamp that can ensure the centering performance of resin tubes even in the case of medium and large diameters with a heavy joint weight while suppressing costs with an inexpensive configuration.

Brief Description of the Drawings

[0027]

Figure 1

Figure 2

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Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

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Figure 14

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Figure 16

Figure 17

Figure 18

Embodiments for Carrying Out the Invention

[0028] Hereinafter, with reference to the drawings, a clamp 100 according to an embodiment of the present invention will be described. The clamp 100 shown in Fig. 1 is used when fusing the resin tube P and the electric fusion joint F by the following steps. Specifically, with the resin tube P made of thermoplastic resin inserted into the electric fusion joint F, a current is loaded from the terminal T provided in the electric fusion joint F. Then, a heating wire (not shown) provided in the electric fusion joint F generates heat. As a result, the surfaces of the electric fusion joint F and the resin tube P are heat-fused.

[0029] When performing the above steps, the clamp 100 according to the present embodiment is attached to the connection portion between the resin tube P and the electric fusion joint F, so as to prevent the positions and central axes of the resin tube P and the electric fusion joint F from shifting. Note that after the resin tube P and the electric fusion joint F are joined, the clamp 100 is left at the connection portion without being reused elsewhere. The clamp 100 according to the present embodiment is made of resin. For example, rigid vinyl chloride, impact-resistant rigid vinyl chloride, polyacetal, nylon, etc. are preferably used. In the following, when defining the directions of each component, the direction of the central axis of the electric fusion joint F may be referred to as the axial direction, the radial direction of the electric fusion joint F and the resin tube P may be referred to as the radial direction, and the direction of going around the axial direction may be referred to as the circumferential direction.

[0030] The clamp 100 shown in Fig. 1 and Fig. 2 includes a tightening band portion 10, an engaging portion 20, and a connecting portion 30. The tightening band portion 10 has a role of holding the resin tube P and the electric fusion joint F in a state where the resin tube P is disposed inside the electric fusion joint F. The tightening band portion 10 includes a tube tightening band portion 11 and a joint tightening band portion 12.

[0031] The tube tightening band portion 11 holds the resin tube P inserted into the electric fusion joint F. The tube tightening band portion 11 is a band-shaped member formed in an annular shape along the circumferential direction of the resin tube P. The circumferential length of the tube tightening band portion 11 is longer than the outer diameter of the resin tube P. In addition, tube-side engaging portions 21 are formed at both ends of the band shape (described later). In addition, tube-side protrusions 11p are provided on the annular inner peripheral surface of the tube tightening band portion 11.

[0032] The pipe-side protrusion 11p is provided at at least one location on the inner peripheral surface of the pipe clamping band portion 11. As shown in FIG. 1, the pipe-side protrusion 11p is provided in an annular shape along the band shape of the pipe clamping band portion 11. Alternatively, a plurality of pipe-side protrusions 11p may be provided at intervals. The pipe-side protrusion 11p is a portion that contacts the resin pipe P when the resin pipe P is held by the pipe clamping band portion 11. By concentrating the force for clamping the resin pipe P by the pipe clamping band portion 11 on the pipe-side protrusion 11p, it has the role of improving the holding force of the resin pipe P.

[0033] The joint clamping band portion 12 holds the electric fusion joint F in a state where the resin pipe P is inserted into the electric fusion joint F. The joint clamping band portion 12 is a band-shaped member formed in an annular shape along the circumferential direction of the electric fusion joint F. Here, the resin pipe P is inserted into the electric fusion joint F held by the joint clamping band portion 12. Therefore, the inner diameter of the annular shape of the joint clamping band portion 12 is larger than the inner diameter of the pipe clamping band portion 11. The circumferential length of the joint clamping band portion 12 is longer than the circumferential length of the pipe clamping band portion 11. Also, the axial length of the joint clamping band portion 12, that is, the width of the band shape of the joint clamping band portion 12, is longer than the axial length of the pipe clamping band portion 11.

[0034] At the opening of the electric fusion joint F into which the resin pipe P is inserted, the outer diameter of the electric fusion joint F is larger than the outer diameter of the resin pipe P. The circumferential length of the joint clamping band portion 12 is longer than the outer diameter of the opening of the electric fusion joint F. Also, the joint clamping band portion 12 and the pipe clamping band portion 11 are connected by a connecting portion 30 (described later). Therefore, the end portion of the joint clamping band portion 12 on the side facing the pipe clamping band portion 11 extends toward the center toward the pipe clamping band portion 11. That is, the joint clamping band portion 12 has an L-shaped cross section.

[0035] Joint-side engaging portions 22 are formed at both ends of the band shape of the joint clamping band portion 12 (described later). Also, a joint-side protrusion 12p is provided on the inner peripheral surface of the annular shape of the joint clamping band portion 12. Further, the joint clamping band portion 12 is provided with a notch portion 12h corresponding to the shape of the electric fusion joint F. The joint-side protrusion 12p is provided at least at one location on the inner peripheral surface of the joint tightening band portion 12. The joint-side protrusion 12p is provided annularly along the band shape of the joint tightening band portion 12. Alternatively, a plurality of them may be provided at intervals. The joint-side protrusion 12p is a part that comes into contact with the electric fusion joint F when the electric fusion joint F is held by the joint tightening band portion 12. When the force for tightening the electric fusion joint F by the joint tightening band portion 12 is concentrated on the joint-side protrusion 12p, it has the role of improving the holding force of the electric fusion joint F.

[0036] The notch portion 12h prevents the joint tightening band portion 12 from being unable to be attached due to interference with the shape of the electric fusion joint F (especially the terminal T) when the joint tightening band portion 12 is attached to the electric fusion joint F. The notch portion 12h is provided in accordance with the shape and size of the terminal T in order to correspond to the shape of the electric fusion joint F. Here, the terminals T provided on the electric fusion joint F may have different sizes and positions depending on the variety even for electric fusion joints F of the same diameter. For this reason, the notch portion is formed so as to be able to correspond to the shapes of a plurality of types of terminals T.

[0037] As shown in FIG. 3, the notch portion 12h includes a first notch portion 12h1 and a second notch portion 12h2. The first notch portion 12h1 is a circular notch provided relatively centrally in the axial direction of the joint tightening band portion 12. As shown in FIGS. 7 and 8, the first notch portion 12h1 is provided near the relatively end portion of the electric fusion joint F and has a shape provided corresponding to a terminal T having a relatively small diameter.

[0038] The second notch portion 12h2 is a semi-circular notch provided at the end side on the side that does not face the pipe tightening band portion 11 in the axial direction of the joint tightening band portion 12. Also, a part of the second notch portion 12h2 is connected to a part of the first notch portion 12h1. As shown in FIGS. 5 and 6, the second notch portion 12h2 is provided at a location relatively far from the vicinity of the end portion of the electric fusion joint F and has a shape provided corresponding to a terminal T having a relatively large diameter.

[0039] As described above, by providing the first notch 12h1 and the second notch 12h2 having different sizes, it becomes possible to cope with a plurality of types of terminal shapes. Alternatively, it may be used for purposes such as using the first notch 12h1 having a relatively large diameter for rough alignment and using the second notch 12h2 having a relatively small diameter for fine positioning.

[0040] The engaging portion 20 is provided at both belt-shaped ends of the above-described tightening belt portion 10. The engaging portion 20 enables the annular diameter of the tightening belt portion 10 to be reduced by engaging both ends of the tightening belt portion 10 with each other in the circumferential direction. Thereby, it has a role of tightening and holding the resin tube P and the electric fusion joint F by the tightening belt portion 10. The engaging portion 20 includes a tube-side engaging portion 21 and a joint-side engaging portion 22.

[0041] The tube-side engaging portion 21 is provided at both belt-shaped ends of the tube tightening belt portion 11. The tube-side engaging portion 21 includes a tube-side male portion 21m and a tube-side female portion 21f. The tube-side male portion 21m is provided at one end of the belt shape of the tube tightening belt portion 11. The tube-side male portion 21m includes a tube-side male engaging tooth 21mt and a tube-side male gripping portion 21mg. The tube-side male engaging tooth 21mt can be inserted into the tube-side female portion 21f and engaged with the tube-side female engaging tooth 21ft. The tube-side male gripping portion 21mg is a portion that rises radially outward on the side of the tube tightening belt portion 11 of the tube-side male portion 21m.

[0042] The tube-side female portion 21f is provided at the other end of the belt shape of the tube tightening belt portion 11. The tube-side female portion 21f includes a tube-side female engaging tooth 21ft and a tube-side female gripping portion 21fg. The side of the tube-side female portion 21f on the tube tightening belt portion 11 rises radially outward. Further, the radially outer end of the rising portion further rises along the circumferential direction toward the other end side of the belt shape of the tube tightening belt portion 11. Thereby, the tube-side female portion 21f has an L-shaped configuration. The L-shaped configuration and the belt shape located at the other end of the tube tightening belt portion 11 form the tube-side female portion 21f.

[0043] The female pipe side portion 21f is provided with female pipe side engaging teeth 21ft on the side facing the strip-shaped pipe tightening band portion 11 at the portion rising in the circumferential direction from the radially outer end of the raised portion. The female pipe side engaging teeth 21ft engage with the male pipe side engaging teeth 21mt, prevent the male pipe side portion 21m from coming out of the female pipe side portion 21f, and have the role of maintaining the diameter-reduced state of the pipe tightening band portion 11. The female pipe side gripping portion 21fg refers to the portion of the female pipe side portion 21f that particularly rises radially outward from the pipe tightening band portion 11.

[0044] When inserting the male pipe side portion 21m into the female pipe side portion 21f, an insertion force is applied by simultaneously clamping the male pipe side gripping portion 21mg and the female pipe side gripping portion 21fg with a tool or hand or the like. Also, when the male pipe side portion 21m is inserted into the female pipe side portion 21f, the tip of the female pipe side portion 21f abuts against the male pipe side gripping portion 21mg. Thereby, the male pipe side gripping portion 21mg also has the role of a stopper that regulates the insertion amount.

[0045] The joint side engaging portion 22 is provided at both ends of the strip shape of the joint tightening band portion 12. The joint side engaging portion 22 includes a male joint side portion 22m and a female joint side portion 22f. The male joint side portion 22m is provided at one end of the strip shape of the joint tightening band portion 12. The male joint side portion 22m includes male joint side engaging teeth 22mt and a male joint side gripping portion 22mg. The male joint side engaging teeth 22mt are inserted into the female joint side portion 22f and can engage with the female joint side engaging teeth 22ft. The male joint side gripping portion 22mg is a portion that rises radially outward on the side of the joint tightening band portion 12 of the male joint side portion 22m.

[0046] The female joint side portion 22f is provided at the other end of the strip shape of the joint tightening band portion 12. The female joint side portion 22f includes female joint side engaging teeth 22ft and a female joint side gripping portion 22fg. On the side of the joint tightening band portion 12 of the female portion 22f on the joint side, it rises radially outward. Further, the radially outer end of the raised portion further rises along the circumferential direction to the other end side of the band shape of the joint tightening band portion 12. Thereby, the female portion 22f on the joint side has an L-shaped configuration. The L-shaped configuration and the band shape located at the other end of the joint tightening band portion 12 form the female portion 22f on the joint side.

[0047] The female engaging teeth 22ft on the joint side are provided on the side portion facing the band shape of the joint tightening band portion 12 in the portion that rises circumferentially from the radially outer end of the raised portion. The female engaging teeth 22ft on the joint side engage with the male engaging teeth 22mt on the joint side, preventing the male portion 22m on the joint side from coming out of the female portion 22f on the joint side, and having the role of maintaining the reduced diameter state of the joint tightening band portion 12. The female gripping portion 22fg on the joint side refers to the portion of the female portion 22f on the joint side that particularly rises radially outward from the joint tightening band portion 12.

[0048] When inserting the male portion 22m on the joint side into the female portion 22f on the joint side, an insertion force is applied by simultaneously clamping the male gripping portion 22mg on the joint side and the female gripping portion 22fg on the joint side with a tool or hand or the like. Further, when the male portion 22m on the joint side is inserted into the female portion 22f on the joint side, the tip of the female portion 22f on the joint side and the male gripping portion 22mg on the joint side abut against each other. Thereby, the male gripping portion 22mg on the joint side also has the role of a stopper for regulating the insertion amount. Hereinafter, the female engaging teeth 21ft on the pipe side, the male engaging teeth 21mt on the pipe side, the female engaging teeth 22ft on the joint side, and the male engaging teeth 22mt on the joint side may be collectively referred to as engaging teeth. Also, the pipe-side protrusion 11p and the joint-side protrusion 12p may be collectively referred to as protrusions.

[0049] As shown in Fig. 2, it is preferable that the pipe-side engaging portion 21 and the joint-side engaging portion 22 are separated from each other in the radial direction. More specifically, it is preferable that the pipe-side male gripping portion 21mg and the pipe-side female gripping portion 21fg of the pipe-side engaging portion 21 and the joint-side male gripping portion 22mg and the joint-side female gripping portion 22fg of the joint-side engaging portion 22 are separated from each other in the radial direction. Here, if these parts are in the same position in the radial direction, when an insertion force is applied to the pipe-side engaging portion 21 and the joint-side engaging portion 22 by a tool or a hand, etc., the pipe-side engaging portion 21 and the joint-side engaging portion 22 may be gripped simultaneously. This may cause the insertion amount of the engaging teeth not to be sufficiently obtained in the pipe-side engaging portion 21 or the joint-side engaging portion 22. By separating these parts from each other in the radial direction as described above, the above problems are prevented from occurring, ensuring that the insertion operation is carried out reliably.

[0050] Also, as shown in Fig. 2, it is preferable that the pipe-side male gripping portion 21mg and the pipe-side female gripping portion 21fg of the pipe-side engaging portion 21 and the joint-side male gripping portion 22mg and the pipe-side female gripping portion 21fg of the joint-side engaging portion 22 are in the same position as each other in the circumferential direction. In other words, from the viewpoint in the axial direction as shown in Fig. 2, it is preferable that these parts are flush with each other. Thereby, when an insertion force is applied to the pipe-side engaging portion 21 and the joint-side engaging portion 22 respectively, a tool or a hand, etc. can be moved smoothly. This ensures an improvement in workability.

[0051] The connecting portion 30 connects the pipe tightening band portion 11 and the joint tightening band portion 12. Thereby, by integrally forming the pipe tightening band portion 11 and the joint tightening band portion 12 in the clamp 100, the resin pipe P and the electrofusion joint F are integrally held by the clamp 100. As shown in Figs. 3 and 4, it is preferable that the connecting portion 30 is provided for about half a circumference in the circumferential direction. In the remaining half-circumference portion in the circumferential direction where the connecting portion 30 is not provided, a gap portion 30s in which the pipe tightening band portion 11 and the joint tightening band portion 12 are not connected is formed.

[0052] Note that it is preferable that the engaging portion 20 is included in the region where the gap portion 30s is formed in the circumferential direction of the clamp 100. That the engaging portion 20 is included in the region where the gap portion 30s is formed means that the end of the joint tightening band portion 12 and the end of the pipe tightening band portion 11 are not connected by the connecting portion 30, and the pipe-side engaging portion 21 and the joint-side engaging portion 22 are independent of each other.

[0053] With such a shape, the engagement of the pipe-side engaging portion 21 and the engagement of the joint-side engaging portion 22 can be performed separately. Here, there are variations in the outer diameters of the resin pipe P and the electric fusion joint F within the range of intersection. Also, the variations in the resin pipe P and the electric fusion joint F are not uniform. For this reason, if the pipe-side engaging portion 21 and the joint-side engaging portion 22 are not independent of each other and are integrated, since the tightening amounts of the pipe-side engaging portion 21 and the joint-side engaging portion 22 are common, any one of the engaging portions 20 may be insufficiently tightened. By being able to perform the engagement of the pipe-side engaging portion 21 and the joint-side engaging portion 22 separately, the above problems can be avoided, and the engagement work using tools and the like can be facilitated.

[0054] The insertion confirmation port 30h is a through hole provided between the pipe tightening band portion 11 and the joint tightening band portion 12. The insertion confirmation port 30h has the role of visualizing the connection portion between the resin pipe P and the electric fusion joint F from the insertion confirmation port 30h in a state where the resin pipe P is inserted into the electric fusion joint F and the clamp 100 is further attached. Thereby, it is used to confirm whether the resin pipe P has come off from the electric fusion joint F.

[0055] It is preferable that at least one or more insertion confirmation ports 30h are provided in the circumferential direction of the clamp 100. The insertion confirmation port 30h is preferably provided at both ends of the connecting portion 30 provided in the circumferential direction, that is, at both ends of the gap portion 30s, as shown in FIGS. 3 and 4, for example. With such a shape, in addition to the above role, the insertion confirmation port 30h also has the role of reducing the stress concentration of the clamp 100 when the tightening band portion 10 is moved and reducing the risk of the material cracking.

[0056] Regarding the holding of the resin pipe P and the electric fusion joint F using the electric fusion joint unit composed of the clamp 100 and the electric fusion joint F having such a configuration, it is carried out as follows. That is, first, as shown in FIG. 9, the clamp 100 is attached to the resin pipe P in advance and arranged at a position sufficiently separated from the insertion allowance of the resin pipe P with respect to the electric fusion joint F. In this state, the resin pipe P is inserted into the electric fusion joint F. Then, as shown in FIG. 10, while aligning the position of the terminal T of the electric fusion joint F and the notch 12h of the joint tightening band portion 12, the clamp 100 is moved along the resin pipe P. Then, using a tool such as pliers, the engaging portions 20 are engaged respectively, and the pipe-side protrusion 11p of the tightening band portion 10 and the joint-side protrusion 12p are brought into contact with the resin pipe P and the electric fusion joint F respectively, thereby holding the resin pipe P and the electric fusion joint F.

[0057] Here, usually, the electric fusion joint F is relatively heavy with respect to the resin pipe P. For this reason, when the resin pipe P is inserted into the electric fusion joint F, the electric fusion joint F tends to deviate from the central axis of the resin pipe P. On the other hand, the axial length of the joint tightening band portion 12 is longer than the axial length of the pipe tightening band portion 11. For this reason, the electric fusion joint F can be firmly fixed. Therefore, the alignment accuracy between the electric fusion joint F and the resin pipe P is improved.

[0058] Next, a modified example of the clamp 100 according to the present embodiment will be described. That is, as shown in FIG. 11, it may be provided with an assembling portion 40. In other words, the clamp 100 according to the present embodiment may be divided in the circumferential direction in the tightening band portion 10. In this case, the assembling portion 40 includes a male-side assembling portion 41 and a female-side assembling portion 42 as shown in FIGS. 11 and 12. Thus, when the clamp 100 is divided, the side provided with the male-side assembling portion 41 may be referred to as the male-side clamp 51, and the side provided with the female-side assembling portion 42 may be referred to as the female-side clamp 52.

[0059] The male-side assembling portion 41 and the female-side assembling portion 42 have shapes that can be engaged with each other, and are engaged by inserting the male-side assembling portion 41 into the female-side assembling portion 42. Although they are the same in that the mutually corresponding shapes engage with each other, they differ in that the engaging portion 20 has engaging teeth and can adjust the insertion amount, while the assembling portion 40 simply combines them with each other.

[0060] Also, in the present embodiment, as shown in FIG. 12, the male-side assembling portion 41 is provided on the side where the pipe-side male portion 21m and the joint-side male portion 22m in the clamp 100 are provided, and the female-side assembling portion 42 is provided on the side where the pipe-side female portion 21f and the joint-side female portion 22f in the clamp 100 are provided, but it is not limited thereto. That is, the above combination may be reversed.

[0061] The male-side assembling portion 41 is formed so as to rise upward in the radial direction from the divided end portion of the tightening band portion 10 in the male-side clamp 51. The male-side assembling portion 41 is preferably, for example, in the shape of a quadrangular prism that can be inserted into the hole 42h of the female-side assembling portion 42. In addition to this, the end portion on the outer side in the radial direction of the quadrangular prism may be provided with a claw-like shape that can be hooked on the female-side assembling portion 42.

[0062] The female-side assembling portion 42 is formed so as to rise further toward the side where the male-side assembling portion 41 is provided from the base, which is a portion formed so as to rise upward in the radial direction from the divided end portion of the tightening band portion 10 in the female-side clamp 52. A hole 42h for receiving the male-side assembling portion 41 is formed in the portion of the female-side assembling portion 42 that rises further from the base.

[0063] The hole 42h penetrates the female-side assembling portion 42 in the radial direction. By inserting the male-side assembling portion 41 into this hole 42h, the male-side assembling portion 41 and the female-side assembling portion 42 are engaged. In the present embodiment, the hole 42h is preferably formed in the shape of a quadrangular prism so as to receive the quadrangular prism shape of the male-side assembling portion 41. Also, when the male-side assembling portion 41 has a claw-like shape as described above, the female-side assembling portion 42 may have a shape corresponding to the claw-like shape.

[0064] Thus, regarding the holding of the resin pipe P and the electric fusion joint F using the clamp 100 composed of the male clamp 51 having the male-side assembly part 41 and the female clamp 52 having the female-side assembly part 42, it is carried out as follows. That is, first, as shown in FIG. 16, with the resin pipe P inserted into the electric fusion joint F in advance, the male clamp 51 and the female clamp 52 are brought closer from the outside in the radial direction of the resin pipe P. At this time, while aligning the position of the terminal T of the electric fusion joint F and the notch 12h of the clamp 100, the female clamp 52 is brought into contact with the resin pipe P and the electric fusion joint F. Next, the male-side assembly part 41 of the male clamp 51 is inserted into the female-side assembly part 42 of the female clamp 52. After that, the tightening band part 10 of the male clamp 51 is moved so as to contact the resin pipe P, and the engaging part 20 is engaged.

[0065] When the clamp 100 is engaged with the resin pipe P and the electric fusion joint F by the above steps, it becomes the state as shown in FIG. 17. Thus, after the assembly part 40 is engaged, it becomes the same assembly state as the clamp 100 without the assembly part 40. The clamp 100 having such a configuration is effective, for example, in the following construction conditions. That is, as shown in FIG. 18, when the distance between the elbows E provided at both ends of the resin pipe P is short due to the layout conditions at the construction site, the length of the resin pipe P may have to be shortened. In this case, as shown in FIGS. 9 and 10, the clamp 100 cannot be sufficiently moved on the resin pipe P. In such a case, for the clamp 100 without the assembly part 40, it is necessary to expand the tightening band part 10 to open, but there is a risk of the clamp 100 being damaged.

[0066] On the other hand, depending on the clamp 100 having the assembly part 40, the clamp 100 can be retrofitted with the resin pipe P inserted into the electric fusion joint F in advance. Therefore, it is effective when it is necessary to directly attach the clamp to the electric fusion joint F without moving it on the resin pipe P.

[0067] As described above, according to the clamp 100 according to the present embodiment, the joint tightening band portion 12 and the pipe tightening band portion 11 are axially connected by the connecting portion 30. That is, the pipe tightening band portion 11 and the joint tightening band portion 12 are integrally provided around the resin pipe P and the electric fusion joint F. Thereby, due to the shape of the clamp 100, not only the resin pipe P but also the electric fusion joint F can be held simultaneously. Therefore, it is possible to prevent a shift or an angle from occurring between the resin pipe P and the joint. As a result, it is possible to prevent an angle from occurring between the resin pipes inserted into the electric fusion joint F. Therefore, the centering performance between the resin pipes can be improved.

[0068] Furthermore, since the clamp 100 according to the present invention does not require a special material or the like, it can have an inexpensive configuration. For this reason, since there is no influence on the cost even when mass-produced, work can be efficiently performed at a plurality of locations.

[0069] Also, the pipe-side engaging portion 21 and the joint-side engaging portion 22 are independent of each other. Thereby, while maintaining the integrality of the pipe tightening band portion 11 and the joint tightening band portion 12, the engaging portion 20 of the pipe tightening band portion 11 and the engaging portion 20 of the joint tightening band portion 12 can be moved independently. Therefore, since it is not necessary to simultaneously reduce the diameter of the pipe tightening band portion 11 and the joint tightening band portion 12, the work can be facilitated.

[0070] Also, the circumferential length of the joint tightening band portion 12 is longer than the circumferential length of the pipe tightening band portion 11. That is, the outer diameter that the joint tightening band portion 12 can hold is larger than the outer diameter that the pipe tightening band portion 11 can hold. Therefore, the resin pipe P and the electric fusion joint F having different outer diameters from each other can be held by one clamp 100.

[0071] Also, the axial length of the joint tightening band portion 12 is longer than the axial length of the pipe tightening band portion 11. Here, the electric fusion joint F is relatively heavy compared to the resin pipe P. On the other hand, since the axial length of the joint tightening band portion 12 is longer than the axial length of the pipe tightening band portion 11, the electric fusion joint F can be more reliably held by the joint tightening band portion 12.

[0072] Further, the pipe-side engaging portion 21 and the joint-side engaging portion 22 are separated from each other in the radial direction of the resin pipe P. Here, if the pipe-side engaging portion 21 and the joint-side engaging portion 22 are in the same position in the radial direction, the diameter reduction of the pipe tightening band portion 11 and the diameter reduction of the joint tightening band portion 12 may be simultaneously performed by a tool or a hand or the like. As a result, there is a possibility that the above-described diameter reduction may not be sufficiently performed. On the other hand, since the pipe-side engaging portion 21 and the joint-side engaging portion 22 are separated from each other in the radial direction, it is possible to avoid the diameter reduction of the pipe tightening band portion 11 and the diameter reduction of the joint tightening band portion 12 from being simultaneously performed. Therefore, the above-described problem can be prevented from occurring.

[0073] Further, on the inner peripheral surfaces of the pipe tightening band portion 11 and the joint tightening band portion 12, protrusions are provided at least at one location each. That is, when the pipe tightening band portion 11 and the joint tightening band portion 12 are reduced in diameter, only the protrusions come into contact with the resin pipe P and the electric fusion joint F, respectively. Therefore, by concentrating the tightening force by the tightening band portion 10 on the protrusions, the holding force by the tightening band portion 10 can be improved.

[0074] Further, the joint tightening band portion 12 is provided with a notch portion 12h corresponding to the shape of the electric fusion joint F. Here, near the end portion of the electric fusion joint F, there may be provided a power supply terminal or an indicator. By providing the notch portion 12h corresponding to such a shape, the clamp 100 can be attached without interfering with the electric fusion joint F.

[0075] Further, the connecting portion 30 is provided with an insertion confirmation port 30h. Thereby, before starting the fusion bonding operation by the electric fusion joint F, the insertion state of the resin pipe P into the electric fusion joint F can be visually confirmed.

[0076] Further, the clamping band portion 10 is circumferentially divided. Here, when the clamping band portion 10 is not divided, when aligning with the electric fusion joint F, in a state where the clamp 100 is inserted into the resin tube P, it is necessary to move the clamp 100 along the axial direction of the resin tube P. At this time, if the length of the resin tube P is short, it may not be possible to move the clamp 100 sufficiently. On the other hand, since the clamp 100 is divided, without moving it over the resin tube P, after bringing the divided clamping band portion 10 closer to the resin tube P from the outside in the radial direction, the engaging portion 20 may be engaged and the assembling portion 40 may be assembled, and the clamp can be directly attached to the electric fusion joint F.

[0077] Note that the technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, although the pipe-side female engaging teeth 21ft and the joint-side female engaging teeth 22ft have been described as being provided on the sides facing the clamping band portion 10 in the L shape, respectively, similar engaging teeth may be provided on the side of the clamping band portion 10 facing the L shape. That is, the pipe-side male engaging teeth 21mt and the joint-side male engaging teeth 22mt may be provided with engaging teeth on both sides in the radial direction. Also, although the insertion confirmation ports 30h have been described as being provided at both circumferential ends of the connecting portion 30, for example, the insertion confirmation ports 30h may be provided so as to provide intermittent portions in the circumferential direction of the connecting portion 30. Also, although it has been described that it is preferable that the pipe-side male gripping portion 21mg and the pipe-side female gripping portion 21fg, and the joint-side male gripping portion 22mg and the joint-side female gripping portion 22fg are in the same position in the circumferential direction, it is not limited thereto. For example, by making the pipe-side engaging portion 21 and the joint-side engaging portion 22 be included in the same quadrant in the four quadrants based on the central axis in the viewpoint from the axial direction as shown in FIG. 2, it may be possible to ensure the improvement of the above-described workability.

[0078] In addition, within the scope not departing from the spirit of the present invention, it is possible to appropriately replace the components in the above-described embodiment with well-known components, and the above-described modification examples may be appropriately combined.

Description of Symbols

[0079] 10 Clamping Band Portion 11 Pipe Clamping Band Portion 12 Joint Clamping Band Portion 12h Notch 20 Engaging Portion 21 Pipe-Side Engaging Portion 22 Joint-Side Engaging Portion 30 Connecting Portion 30h Insertion Confirmation Port 40 Assembly Portion 100 Clamp F Electric Fusion Joint P Resin Pipe

Claims

1. A resin clamp that holds a resin tube made of a thermoplastic resin and an electric fusion joint to which the resin tube is connected by heat fusion, In a state where the resin tube is disposed inside the electric fusion joint, a belt-shaped tube tightening band portion that can be reduced in diameter to hold the resin tube, and a belt-shaped joint tightening band portion that can be reduced in diameter to hold the electric fusion joint, a tightening band portion provided with, An engaging portion that maintains the reduced diameter state of the tightening band portion by engaging with each other in the circumferential direction that circulates around the axial direction of the tightening band portion, Comprising, The engaging portion includes a tube-side engaging portion provided on the tube tightening band portion and a joint-side engaging portion provided on the joint tightening band portion, Engaging teeth that can engage with each other are formed on the engaging portion, The joint tightening band portion and the tube tightening band portion are axially connected by a connecting portion, Both the joint tightening band portion and the tube tightening band portion are divided in the circumferential direction, and at the divided portions, an assembling portion including a male-side assembling portion and a female-side assembling portion for assembling the divided joint tightening band portion and the tube tightening band portion to each other is provided. There is, The male-side assembling portion and the female-side assembling portion have shapes that can engage with each other, Clamp.

2. The engaging portion is provided at an end portion in the circumferential direction of the tightening band portion, The end portion of the joint tightening band portion and the end portion of the tube tightening band portion are not connected by the connecting portion, and the tube-side engaging portion and the joint-side engaging portion are independent of each other, The clamp according to claim 1.

3. The circumferential length of the joint tightening band portion is longer than the circumferential length of the tube tightening band portion, The clamp according to claim 1 or 2.

4. The axial length of the joint tightening band portion is longer than the axial length of the tube tightening band portion, The clamp according to any one of claims 1 to 3.

5. The tube-side engaging portion and the joint-side engaging portion are separated from each other in the radial direction of the resin tube, The clamp according to any one of claims 1 to 4.

6. On the inner peripheral surfaces of the tube tightening band portion and the joint tightening band portion, protrusions are provided at least at one location each, The clamp according to any one of claims 1 to 5.

7. The joint tightening band portion is provided with a notch corresponding to the shape of the electric fusion joint, The clamp according to any one of claims 1 to 6.

8. The connecting portion is characterized in that at least one insertion confirmation port for confirming the insertion state of the resin tube into the electric fusion joint is provided. The clamp according to any one of claims 1 to 7.

9. An electric fusion joint for connecting the resin tubes by heat fusion, The clamp according to any one of claims 1 to 8, comprising an electric fusion joint unit.

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