Pipe joining device and pipe joining method

Abstract

To provide a pipe joining device and a pipe joining method that can appropriately join opening end portions with each other by aligning center axis lines of first and second pipe members even if the pipe members are reinforced with fiber-reinforced plastic.SOLUTION: A pipe joining device 1A comprises: first and second bases 2, 3; a first clamp part 5 which is provided on the first base and holds a first pipe member P1 made of resin; and a second clamp part 6 which is provided on the second base and holds a second pipe member P2 made of resin. At least one of the clamp parts includes a pair of clamp bodies 17 which can move close to / apart from each other. Each of the pair of clamp bodies is provided with: an opposite surface 21 which faces an outer peripheral surface of one pipe member so as to surround the outer peripheral surface; and a centering mechanism 30A including a movable claw 31A abutting on the outer peripheral surface of the one pipe member. The centering mechanism freely adjusts a distance L between the opposite surface of the clamp body and an abutting part 35 of the movable claw abutting on the outer peripheral surface of the one pipe member when the one pipe member is held with the one clamp part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pipe joining device and a pipe joining method for joining open ends of a pair of resin pipe members. [Background technology]

[0002] Conventionally, a pipe joining device for joining open ends of a pair of resin piping members, such as pipes and fittings, has been generally known. Such a pipe joining device often includes, for example, a first base and a second base that are movable toward and away from each other along a movement axis, a first clamp unit mounted on the first base and configured to hold the first resin piping member so that its central axis extends parallel to the movement axis, and a second clamp unit mounted on the second base and configured to hold the second resin piping member so that its central axis extends parallel to the movement axis. In this configuration, during joining, the central axes of the first piping member held by the first clamp unit and the second piping member held by the second clamp unit are first aligned and their ends are positioned opposite each other. The bases are then moved toward each other to join the open ends of the first and second piping members. The opening ends of the first and second piping members can be joined together by any suitable method, such as welding by melting each opening end using a heater, or bonding by applying an adhesive to the outer peripheral surface of the opening end of one of the piping members.

[0003] Furthermore, the above-mentioned clamping unit generally includes a pair of clamp bodies that are movable horizontally toward and away from each other while sandwiching a piping member, as described in Patent Document 1, for example. In such a clamping unit, the pair of clamp bodies are brought close to each other so that substantially triangular cutouts formed on each clamp body come into contact with the outer peripheral surface of the piping member, thereby gripping the piping member. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-216046 Summary of the Invention [Problem to be solved by the invention]

[0005] Piping plants sometimes use piping components reinforced with fiber-reinforced plastics (hereinafter also referred to as "FRP"). Stress concentration is particularly likely to occur at elbow-type and tee-type joints, making it desirable to use FRP-reinforced joints to reinforce joints and bends. Piping components reinforced with FRP are obtained, for example, by spirally wrapping tape-like FRP around the outer periphery of a piping component while partially overlapping it. This tape-like FRP is not wrapped evenly, and an uneven FRP reinforcing layer is formed on the outer periphery of the FRP-reinforced piping component.

[0006] However, in the clamping unit described above, a pair of clamp bodies is brought close to each other so that the approximately triangular notches formed on each clamp body come into contact with the outer peripheral surface of the piping component to grip the piping component. Therefore, when gripping a piping component reinforced with FRP, the unevenness of the FRP reinforcing layer cannot be absorbed, and the piping component may be gripped misaligned. Therefore, in a pipe connecting device equipped with the clamping unit described above, the central axes of the piping components gripped by each clamping unit cannot be aligned, resulting in misalignment (e.g., misalignment of approximately 1 to 2 mm). This misalignment can easily lead to installation defects (e.g., leaks, disconnections, breakage, etc.). To solve the above-mentioned problems, it is conceivable to reinforce the piping members with FRP after joining the solid piping members, but this would require a lot of work.

[0007] The present invention has been made in consideration of the above-described current situation, and aims to provide a pipe joining device and a pipe joining method using the same that can align the central axes of the first piping member and the second piping member and properly join the open ends of the first piping member and the second piping member, even when a piping member reinforced with fiber-reinforced plastic is used as at least one of the first piping member and the second piping member made of resin. [Means for solving the problem]

[0008] The present invention is as follows. 1. A piping joining device comprising: a first base and a second base that are movable toward and away from each other along a movement axis; a first clamping unit that is provided on the first base and that holds a first piping member made of resin so that its central axis extends parallel to the movement axis; and a second clamping unit that is provided on the second base and that holds a second piping member made of resin so that its central axis extends parallel to the movement axis, wherein the first base and the second base are brought closer to each other to join open ends of the first piping member held by the first clamping unit and the second piping member held by the second clamping unit, At least one of the first clamp portion and the second clamp portion includes a pair of clamp bodies that are movable toward and away from each other on a plane perpendicular to the movement axis, Each of the pair of clamp bodies has an opposing surface that faces the outer peripheral surface of one of the piping members disposed between the pair of clamp bodies when the pair of clamp bodies are brought close to each other, and surrounds the outer peripheral surface of the one of the piping members. A centering mechanism is also provided, which has a movable gripper that is disposed at a position away from the opposing surface toward the one of the piping members so as to abut against the outer peripheral surface of the one of the piping members. The centering mechanism is a piping connecting device characterized in that when the pair of clamp bodies are brought close to each other to grip one of the piping members with one of the clamp sections, in order to align the central axes of the first piping member gripped by the first clamp section and the second piping member gripped by the second clamp section, the centering mechanism can freely adjust the distance between the opposing surfaces of the clamp bodies and the abutment portion of the movable gripping device that abuts against the outer peripheral surface of the one of the piping members. 2. The centering mechanism is a piping joining device described in 1 above, which comprises the movable gripper, a moving mechanism that moves the movable gripper steplessly in at least one of the directions toward and away from the opposing surface when the pair of clamp bodies are brought close to each other to grip one of the piping components with one of the clamp sections, and a positioning mechanism that restricts the movement of the movable gripper that is in contact with the outer peripheral surface of the one of the piping components. 3. The pipe connecting device according to 2. above, wherein the centering mechanism is provided with a linear motion mechanism that linearly moves the movable gripping tool. 4. The pipe connecting device according to 2. or 3. above, wherein the moving mechanism is a biasing member that biases the movable gripper in a direction away from the opposing surface. 5. The positioning mechanism comprises a first regulating member attached to the movable gripper and having a first inclined surface inclined with respect to the direction of movement of the movable gripper, and a second regulating member provided on the clamp body so as to be movable and positionable in a direction perpendicular to the direction of movement of the movable gripper and having a second inclined surface inclined with respect to the direction of movement of the movable gripper and engageable with the first inclined surface, and the piping connecting device described in 4. above can regulate the movement of the movable gripper by positioning the second regulating member while engaging the first inclined surface with the second inclined surface by movement of the second regulating member. 6. The centering mechanism comprises the movable gripper, a moving mechanism that moves the movable gripper in a stepless manner in a direction approaching the opposing surface when the pair of clamp bodies are brought close to each other and one of the clamp portions grips the one piping member, a positioning mechanism that restricts the movement of the movable gripper that is in contact with the outer peripheral surface of the one piping member, and a linear motion mechanism that linearly moves the movable gripper, the moving mechanism is a biasing member that biases the movable gripper in a direction away from the opposing surface, The positioning mechanism comprises a first restricting member attached to the movable gripper and having a first inclined surface inclined with respect to the direction of movement of the movable gripper, and a second restricting member provided on the clamp body so as to be movable and positionable in a direction perpendicular to the direction of movement of the movable gripper and having a second inclined surface inclined with respect to the direction of movement of the movable gripper and engageable with the first inclined surface, and the piping connecting device described in 1 above can restrict the movement of the movable gripper by positioning the second restricting member in a state in which the first inclined surface and the second inclined surface are engaged by movement of the second restricting member. 7. A piping connection device described in any one of 1. to 6. above, wherein at least one of the first piping member and the second piping member is a pipe or fitting reinforced with fiber-reinforced plastic. 8. The pipe connecting device according to any one of 1. to 7. above, which connects the open ends of the first pipe member and the second pipe member to each other in a socket manner. 9. The pipe connecting device according to any one of 1. to 8. above, wherein the first pipe member and the second pipe member are made of polyvinyl chloride, polyethylene, polypropylene, or polyvinylidene fluoride. 10. The pipe connecting device according to any one of 1. to 9. above, further comprising a heater for melting the open ends of the first pipe member and the second pipe member. 11. A pipe joining method, comprising joining open ends of a first pipe member and a second pipe member using the pipe joining device according to any one of 1. to 10. above. [Effects of the Invention]

[0009] According to the present invention, at least one of the first and second clamping units includes a pair of clamp bodies movable toward and away from each other on a plane perpendicular to the movement axis, each of the pair of clamping units having an opposing surface that faces the outer circumferential surface of one of the piping members disposed between the pair of clamping units when the pair of clamping units is brought toward each other and surrounds the outer circumferential surface of the one of the piping members, and a centering mechanism including a movable gripper that is positioned away from the opposing surface toward the one of the piping members and abuts against the outer circumferential surface of the one of the piping members. The centering mechanism can freely adjust the distance between the opposing surface of the clamp body and the abutment portion of the movable gripper that abuts against the outer circumferential surface of the one of the piping members when the pair of clamping units are brought toward each other and one of the piping members is gripped by one of the clamping units, so as to align the central axes of the first piping member gripped by the first clamping unit and the second piping member gripped by the second clamping unit. As a result, even when a piping member reinforced with fiber-reinforced plastic is used as at least one of the first and second resin piping members, the centering mechanism adjusts the distance between the opposing surface of the clamp body and the abutment portion of the movable gripper that abuts against the piping member in accordance with the irregularities on the outer peripheral surface of the piping member reinforced with fiber-reinforced plastic, thereby absorbing the irregularities on the outer peripheral surface of the piping member and gripping the piping member without misalignment. Therefore, the central axes of the first piping member gripped by the first clamp unit and the second piping member gripped by the second clamp unit can be aligned, allowing the open ends to be properly joined together.

[0010] Furthermore, if the centering mechanism comprises the movable gripping device, a moving mechanism that moves the movable gripping device steplessly in at least one of the directions toward and away from the opposing surface when the pair of clamp bodies are brought close to each other and one of the clamp portions grips the one piping member, and a positioning mechanism that restricts the movement of the movable gripping device abutting against the outer peripheral surface of the one piping member, the centering mechanism can be constructed with a simple structure. Furthermore, when the centering mechanism includes a linear motion mechanism that linearly moves the movable gripper, the movable gripper can be smoothly linearly moved. Furthermore, if the movement mechanism is a biasing member that biases the movable gripper in a direction away from the opposing surface, the movable gripper can be easily moved. Furthermore, if the positioning mechanism includes a first regulating member and a second regulating member, and the movement of the movable gripper can be regulated by positioning the second regulating member while engaging the first inclined surface with the second inclined surface by movement of the second regulating member, the movement of the movable gripper can be easily regulated. Furthermore, if at least one of the first piping member and the second piping member is a pipe or fitting reinforced with fiber-reinforced plastic, one of the clamp portions can grip the pipe or fitting reinforced with fiber-reinforced plastic without misalignment. Furthermore, when the open ends of the first piping member and the second piping member are joined together using a socket method, the open ends of the first and second piping members are joined together by inserting the open end of one piping member into the open end of the other piping member. Furthermore, when the material of the first piping member and the second piping member is polyvinyl chloride, polyethylene, polypropylene, or polyvinylidene fluoride, the open ends of the first and second piping members made of a material that is relatively inexpensive and easily available are joined together. Furthermore, when a heater mechanism for melting the open ends of the first piping member and the second piping member is provided, the open ends of the first and second piping members are fused together. [Brief explanation of the drawings]

[0011] The present invention will be further described in the following detailed description, which provides non-limiting examples of exemplary embodiments according to the present invention, and with reference to the mentioned drawings, in which like reference numerals refer to like parts throughout the several views of the drawings.

[0012] [Figure 1] FIG. 2 is a side view of the pipe connecting device of the present embodiment. [Figure 2] FIG. 2 is an enlarged view of a main part of FIG. [Figure 3] FIG. 3 is an enlarged view taken along the arrow III in FIG. 2. [Figure 4] FIG. 4 is an enlarged view of the main part of FIG. 3 with the set screw removed. [Figure 5] FIG. 4 is an enlarged view of a main part of FIG. 3, showing a state in which the cover member is in cross section. [Figure 6] FIG. 4 is an enlarged view of a main part of FIG. 3, showing a cross section of the base member. [Figure 7] FIG. 2 is a perspective view of a clamp body equipped with the centering mechanism of the present embodiment. [Figure 8] FIG. 2 is an exploded perspective view of the centering mechanism of the present embodiment. [Figure 9] 10A and 10B are explanatory diagrams for explaining the pipe joining method (preparation process) of this embodiment, in which (a) shows the state in which the second clamp portion and the heater plate are centered, and (b) shows the state in which the first clamp portion and the second clamp portion are centered. [Figure 10] 1A and 1B are explanatory diagrams for explaining the piping joining method (first gripping step) of this embodiment, in which (a) shows the state in which the first clamp part is brought close to the second clamp part, and (b) shows the state in which the pipe is gripped by the first clamp part. [Figure 11] 1A and 1B are explanatory diagrams for explaining the pipe joining method (pipe centering process) of this embodiment, in which (a) shows the state in which the fitting is inserted into the pipe, and (b) shows the state in which the fitting is positioned at the reference position. [Figure 12] 10A and 10B are explanatory diagrams for explaining the pipe joining method (second gripping step) of this embodiment, in which (a) shows the state in which the movable claw faces the outer peripheral surface of the joint, (b) shows the state in which the movable claw abuts the outer peripheral surface of the joint, and (c) shows the state in which the joint is temporarily gripped by the movable claw. [Figure 13] 1A and 1B are explanatory diagrams for explaining the pipe joining method (pipe joining process) of this embodiment, in which (a) shows a state in which the fitting and the pipe are separated, and (b) shows a state in which a heater is placed between the fitting and the pipe. [Figure 14] 1A and 1B are explanatory diagrams for explaining the pipe joining method (pipe joining process) of this embodiment, in which (a) shows a state in which a heater is inserted into a fitting and a pipe, (b) shows a state in which the fitting and the pipe are removed from the heater, and (c) shows a state in which the fitting and the pipe are fused together. [Figure 15] 10A and 10B are explanatory views for explaining a centering mechanism of another embodiment, in which (a) is a front view and (b) is a view seen from the arrow b. [Figure 16] 16A and 16B are enlarged cross-sectional views of a portion of the main part of FIG. 15, where (a) shows a form in which the movable claw can rotate around the axis of the screw, and (b) shows a form in which the movable claw can tilt relative to the axis of the screw. [Figure 17] 10A and 10B are explanatory views for explaining a centering mechanism according to still another embodiment. [Figure 18] 10A and 10B are explanatory views for explaining a centering mechanism according to still another embodiment. [Figure 19] 10A and 10B are explanatory views for explaining a centering mechanism according to still another embodiment. [Figure 20] 10A and 10B are explanatory views for explaining a centering mechanism according to still another embodiment. [Figure 21] 10 is an explanatory view for explaining a second clamping portion of another embodiment. FIG. [Figure 22] An explanatory diagram for explaining another embodiment of a pipe joining device, where (a) shows the state in which the centering jig is inserted into the pipe, and (b) shows the state in which the centering jig is inserted into the fitting and the pipe. DETAILED DESCRIPTION OF THE INVENTION

[0013] The matters set forth herein are for illustrative purposes only and are intended to provide an illustrative description of the embodiments of the present invention, with the aim of providing what is believed to be the most effective and easily understandable explanation of the principles and conceptual features of the present invention. In this regard, it is not intended to show structural details of the present invention beyond the extent necessary for a fundamental understanding of the present invention, and the description, taken together with the drawings, will make clear to those skilled in the art how some forms of the present invention may be actually embodied.

[0014] The present invention will be specifically described below with reference to the drawings and embodiments. In this embodiment, a pipe connecting device 1A is illustrated that uses a socket method to fuse (including contact and non-contact methods) the open ends of a resin pipe P1 (exemplified as the "first piping member" of the present invention) and a resin fitting P2 (exemplified as the "second piping member" of the present invention) together (see FIG. 1). Specifically, this pipe connecting device 1A inserts the open end of the pipe P1 into the open end (connection socket) of the fitting P2 to fuse the open ends together. The outer periphery of the fitting P2 is reinforced with fiber-reinforced plastic (hereinafter also referred to as "FRP"), while the outer periphery of the pipe P1 is not reinforced with FRP. An uneven FRP reinforcing layer R is formed on the outer periphery of the fitting P2 (see FIG. 2). Furthermore, the pipe P1 and the joint P2 are made of polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP), or polyvinylidene fluoride (PVDF) for ultrapure water. However, the pipe P1 and the joint P2 may also be made of chlorinated polyvinyl chloride (PVC-C), acrylonitrile butadiene styrene resin (ABS resin), perfluoroalkoxyalkane (PFA), polyphenylene sulfide (PPS), etc.

[0015] However, the types, FRP reinforcement forms, and uses of the "first piping member" and "second piping member" according to the present invention are not particularly limited. Examples of the types of the first and second piping members include pipes (straight pipes, curved pipes, etc.), joints (elbow-type, tee-type, bend-type, socket-type, etc.), caps, flanges, etc. The first and second piping members may be of different types or the same type. Examples of the FRP reinforcement forms of the first and second piping members include a form in which only one piping member is reinforced with FRP, and a form in which both piping members are reinforced with FRP. Examples of uses of the first and second piping members include ultrapure water used in semiconductor manufacturing, general use, tap water, agricultural water, plant piping, and heat-resistant uses such as hot water.

[0016] 1, a piping connecting device 1A according to this embodiment includes a first base 2 and a second base 3 that are movable toward and away from each other along a movement axis M, a first clamp unit 5 that is provided on the first base 2 and that holds a pipe P1 so that a central axis O1 extends parallel to the movement axis M, and a second clamp unit 6 that is provided on the second base 3 and that holds a fitting P2 so that a central axis O2 extends parallel to the movement axis M. Note that FIGS. 1 to 3 show a state in which the pipe P1 is held by the first clamp unit 5, and the open end of the pipe P1 is inserted into the open end of the fitting P2, thereby aligning the pipe P1 and the fitting P2.

[0017] The first base 2 and the second base 3 are provided so as to be movable toward and away from each other along a movement axis M by a guide device 9 such as a guide rail provided on a platform 8 installed on the floor. By manually rotating an operating handle 11 provided on the first base 2, the first base 2 can be moved along the movement axis M by following the guide device 9, while the second base 3 is fixed to the platform 8 and cannot move. However, the manner in which the first base 2 and the second base 3 move is not particularly limited. The first base 2 may be fixed to the platform 8 and cannot move, while the second base 3 may be moved along the movement axis M by following the guide device 9, or both the first base 2 and the second base 3 may be moved along the movement axis M by the guide device 9. Furthermore, the movement of the first base 27 and the second base 3 may be performed automatically, for example, by driving a drive source (e.g., a pneumatic cylinder, a hydraulic cylinder, a motor, etc.), rather than manually as described above.

[0018] The first base 2 and the second base 3 each have a flat table surface 2a, 3a formed on their upper surfaces, extending horizontally at the same height. A first clamp unit 5 is provided on the table surface 2a of the first base 2, and a second clamp unit 6 is provided on the table 3a of the second base 3. The first clamp unit 5 holds the pipe P1 so that the central axis O1 of the pipe P1 extends parallel to the movement axis M. Furthermore, the second clamp unit 6 holds the fitting P2 so that the central axis O2 of the open end of the fitting P2, into which the open end of the pipe P1 closer to the second base 3 should be inserted, coincides with the central axis O1 of the open end of the pipe P1 held by the first clamp unit 5.

[0019] The first clamp unit 5 includes a pair of clamp bodies 13 that can be opened and closed in a horizontal direction (i.e., width direction) perpendicular to the movement axis M. Multiple pairs of clamp bodies 13 (two pairs in FIG. 1 ) are provided spaced apart in the direction of the movement axis M. Each of the multiple pairs of clamp bodies 13 is attached to a pair of clamp mounts 14 provided on the table surface 2a of the first base 2 so as to face each other. The pair of clamp mounts 14 are guided by guide rails (not shown) to open and close horizontally on the table surface 2a perpendicular to the movement axis M by manually operating an operating handle 15 provided on the first base 2. By closing the pair of clamp mounts 14, one pipe P1 is gripped between the multiple pairs of clamp bodies 13 so that the central axis O1 of the open end of the pipe P1 extends parallel to the movement axis M. However, the manner in which the pair of clamp mounting bases 14 are opened and closed is not particularly limited, and instead of being opened and closed manually as described above, the pair of clamp mounting bases 14 may be opened and closed automatically, for example, by driving a drive source (e.g., a pneumatic cylinder, a hydraulic cylinder, a motor, etc.).

[0020] Each clamp body 13 is well known and will not be described in detail here, but for example, it can be a plate-like member of the same shape with a triangular cutout of the same shape at the same height in the center, and the two sides flanking the apex can abut against the outer surface of the pipe P1.

[0021] The second clamp unit 6 includes a pair of clamp bodies 17 that are movable toward and away from each other in a horizontal direction (i.e., width direction) perpendicular to the movement axis M. Each of the pair of clamp bodies 17 is attached to a pair of clamp mounts 18 provided on the table surface 3a of the second base 3 so as to face each other. The pair of clamp mounts 18 are guided by guide rails (not shown) to open and close horizontally on the table surface 3a perpendicular to the movement axis M by manual operation of an operation handle 19 provided on the second base 3. As the pair of clamp mounts 18 open and close, the pair of clamp bodies 17 move toward and away from each other horizontally perpendicular to the movement axis M. By bringing the pair of clamp bodies 17 toward each other and abutting the movable claws 31A (exemplified as the "movable gripper" according to the present invention) against the outer circumferential surface of the joint P2, the movable claws 31A grip the joint P2 so that the central axis O2 of the open end of the joint P2 extends parallel to the movement axis M. However, the manner in which the pair of clamp bodies 17 are moved is not particularly limited, and instead of being moved manually as described above, the pair of clamp bodies 17 may be moved automatically so as to move closer to or away from each other by driving a drive source (e.g., a pneumatic cylinder, a hydraulic cylinder, a motor, etc.).

[0022] The "movable gripping device" according to the present invention is not particularly limited as long as it can exert an anti-slip effect to prevent the piping members from slipping in the central axis direction when the open ends of the first piping member and the second piping member are joined together, and may be, for example, a movable claw made of metal or resin, a rubber device that comes into contact with the outer peripheral surface of the piping member with elastic deformation, or a suction cup device that adheres to the outer peripheral surface of the piping member.

[0023] As shown in FIGS. 3 and 7 , each of the pair of clamp bodies 17 has an opposing surface 21 that surrounds the outer peripheral surface of the joint P2 disposed between the pair of clamp bodies 17 when the pair of clamp bodies 17 is brought close to each other. The pair of clamp bodies 17 has identical isosceles trapezoidal notches 22 at the same height in the center. The surfaces of the notches 22 that face the outer peripheral surface of the joint P2 form the opposing surface 21. The opposing surface 21 has a flat surface 21a extending in the vertical direction and a flat surface 21b that is connected to the upper and lower ends of the flat surface 21a and extends in a direction inclined relative to the vertical direction. The flat surface 21a faces the outer peripheral surface of the joint P2 in the horizontal direction, and the flat surface 21b faces the outer peripheral surface of the joint P2 in a direction inclined relative to the vertical direction. However, the shape of the notch 22 is not particularly limited. In addition to the isosceles trapezoidal shape described above, other shapes such as a triangle, a semicircle, or an arch shape may also be used. Naturally, the shape of the opposing surface 21 changes depending on the shape of the notch 22. Furthermore, a plate-shaped base member 23 is attached to the front surface side of the pair of clamp bodies 17, and a rib plate 24 extending in the vertical direction is attached to the front surface side of this base member 23. A cover member 25 is attached to the front surface side of this base member 23 so as to cover it. Furthermore, a mounting plate 26 that is fixed to the clamp mounting base 18 is attached to the lower end of the pair of clamp bodies 17.

[0024] Each of the pair of clamp bodies 17 is provided with a centering mechanism 30A including one movable claw 31A located away from the opposing surface 21 of the clamp body 17 toward the joint P2 so as to abut against the outer circumferential surface of the joint P2 when the pair of clamp bodies 17 are brought close to each other. A plurality of centering mechanisms 30A (two in FIG. 3) are provided on each of the pair of clamp bodies 17. Furthermore, the centering mechanisms 30A are located at positions corresponding to the flat surface 21b of the opposing surface 21 of the clamp body 17.

[0025] In order to align the central axes O1, O2 of the pipe P1 held by the first clamp section 5 and the fitting P2 held by the second clamp section 6, when a pair of clamp bodies 17 are brought close to each other and the fitting P2 is held by the second clamp section 6, the centering mechanism 30A can freely adjust the radial distance L of the fitting P2 between the opposing surface 21 of the clamp body 17 and the abutment portion 35 of the movable claw 31A abutting the outer peripheral surface of the fitting P2 (i.e., the protrusion amount (amount of protrusion) from the opposing surface 21 of the movable claw 31A) (see Figure 12).

[0026] As shown in Figures 4 to 6, the centering mechanism 30A includes a movable claw 31A, a moving mechanism 32A that continuously moves the movable claw 31A in a direction approaching the opposing surface 21 of the clamp body 17 when the pair of clamp bodies 17 are brought close to each other and the joint P2 is gripped by the second clamp section 6, a positioning mechanism 33A that restricts the movement of the movable claw 31A abutting the outer peripheral surface of the joint P2, and a linear motion mechanism 34A that linearly moves the movable claw 31A.

[0027] The movable claw 31A is formed in a plate shape that is elongated in a direction parallel to the tangent direction of the outer periphery of the joint P2 that is disposed between the pair of clamp bodies 17 (see FIG. 7). The movable claw 31A is disposed at a position away from the opposing surface 21 of the clamp body 17 so as to protrude from the opposing surface 21 toward the joint P2. The movable claw 31A has a number of non-slip irregularities formed on the surface that abuts against the outer periphery of the joint P2. A guide member 36 that is formed in a plate shape and is wider than the movable claw 31A is attached to the back side of the movable claw 31A. A stopper 37 that abuts against the axial end surface of the open end of the joint P2 is provided at the end of the guide member 36 that is closer to the first clamp unit 5 to position the joint P2 at a reference position of the second clamp unit 6 when centering the pipe P1 and the joint P2 (see FIG. 2). Furthermore, a movable shaft 38 extending toward the clamp body 17 is attached to the back side of the guide member 36 at a position corresponding to the center of the movable claw 31A in the longitudinal direction (see FIG. 6). This movable shaft 38 is inserted into a support hole 39 formed in the base member 23. Furthermore, the tip side of the movable shaft 38 has a small diameter and a step portion 38a.

[0028] The movement mechanism 32A is a biasing member 40 (e.g., a coil spring, a fluid spring, or the like) that biases the movable claw 31A in a direction away from the opposing surface 21 of the clamp body 17 (i.e., a direction toward the joint P2). When the pair of clamp bodies 17 are brought close to each other and the second clamp unit 6 grips the joint P2, the biasing member 40 contracts as the movable claw 31A abuts against the outer circumferential surface of the joint P2 against the biasing force of the biasing member 40, thereby continuously moving the movable claw 31A in a direction toward the opposing surface 21 (see FIG. 12 ). The biasing member 40 also biases the movable claw 31A in a direction toward the central axis O2 of the joint P2. The biasing member 40 is disposed between the bottom surface of the support hole 39 of the base member 23 and the stepped portion 38a of the moving shaft 38. When the biasing member 40 is in the most extended state (i.e., in the natural state), the distance L between the opposing surface 21 of the clamp body 17 and the abutment portion 35 of the movable claw 31A is at a maximum value L1 (see FIG. 12(a)). In this embodiment, the adjustment range of the distance L is about 10 mm. If this adjustment range is long, it becomes disadvantageous in terms of strength, and if it is short, it becomes difficult to adjust the distance L.

[0029] The positioning mechanism 33A includes a first restricting member 41 (also referred to as a "tapered stem") attached to the movable claw 31A and having a first inclined surface 41a inclined with respect to the movement direction of the movable claw 31A, and a second restricting member 42 (also referred to as a "tapered block") provided on the clamp body 17 so as to be movable and positionable in a direction perpendicular to the movement direction of the movable claw 31A and having a second inclined surface 42a inclined with respect to the movement direction of the movable claw 31A and engageable with the first inclined surface 41a (see FIG. 5). The positioning mechanism 33A can restrict the movement of the movable claw 31A by positioning the second restricting member 42 in a state in which the first inclined surface 41a and the second inclined surface 42a are engaged by movement of the second restricting member 42.

[0030] The first restricting member 41 is attached to the rear surface of the guide member 36 so as to protrude toward the clamp body 17. A first inclined surface 41a is formed on the protruding end of the first restricting member 41. The second restricting member 42 is disposed between a recess 44 (guide portion) formed on the rear surface of the cover member 25 and the surface of the base member 23. The recess 44 is elongated in a direction perpendicular to the movement direction of the movable claw 31A. The second restricting member 42 is provided to be movable within the recess 44 along its longitudinal direction. An insertion hole 45, which is continuous with the recess 44 and into which the first restricting member 41 is inserted, is formed at the end of the cover member 25 facing the guide member 36. The first inclined surface 41a and the second inclined surface 42a are engageable within the recess 44. An elongated hole 46, which is narrower than the recess 44 and continuous with the recess 44, is formed on the surface of the cover member 25. The elongated hole 46 is elongated in a direction perpendicular to the movement direction of the movable claw 31A. A positioning screw 47 (see FIG. 7), such as a thumbscrew, is threaded into the second restricting member 42 through the elongated hole 46. By operating the positioning screw 47 to move the second restricting member 42, the first inclined surface 41 a and the second inclined surface 42 a can be engaged and disengaged. Furthermore, by screwing the positioning screw 17 into the second restricting member 42, the thin-walled portion that forms the recess 44 of the cover member 25 is sandwiched between the head of the positioning screw 17 and the second restricting member 42, and the second restricting member 42 is positioned.

[0031] The positioning mechanism 33A may be automatically operated by a drive source (for example, a pneumatic cylinder, a hydraulic cylinder, a motor, etc.) instead of being manually operated as described above. In this case, for example, the second restricting member 42 may be moved in a direction perpendicular to the moving direction of the movable claw 31A by driving the drive source, and the second restricting member 42 may be positioned by stopping the driving of the drive source.

[0032] The linear motion mechanisms 34A are disposed on both longitudinal sides of the movable claw 31A, sandwiching the biasing member 40 (see FIG. 6). The linear motion mechanism 34A includes a bushing 52 (bearing sleeve) inserted into an insertion hole 51 formed in the base member 23 and attached to the base member 23, and a linear motion shaft 53 guided within the bushing 52 for linear motion. One end of the linear motion shaft 53 is attached to the rear surface of the guide member 36. The linear motion mechanism 34A also includes a restriction mechanism (not shown) that restricts the linear motion shaft 53 from projecting toward the movable claw 31A. Note that the linear motion mechanism 34A may employ, in addition to the linear bushing described above, an oil-free bushing, a linear guide, or the like. Furthermore, if the movable claw 31A can be linearly moved by the biasing member 40 alone, the linear motion mechanism 34A is not necessarily required.

[0033] Here, in the second clamp section 6, from a state in which the distance L between the opposing surface 21 of the clamp body 17 and the abutment portion 35 of the movable claw 31A is at a maximum value L1 (see FIG. 12(a)), the pair of clamp bodies 17 is brought closer to each other so that the movable claw 31A abuts against the outer peripheral surface of the joint P2, and the biasing member 40 is shortened so as to absorb the irregularities in the FRP reinforcing layer R of the joint P2, and the centering mechanism 30A adjusts the distance L to a value L2 smaller than the maximum value L1 (see FIG. 12(b)). Furthermore, from this state, the pair of clamp bodies 17 is brought even closer to each other, and the centering mechanism 30A adjusts the distance L to a value L3 (e.g., approximately 5 mm) smaller than the value L2 (see FIG. 12(c)). In this state, the positioning mechanism 33A positions the second restricting member 42 with the first inclined surface 41a and the second inclined surface 42a engaged, thereby restricting the movement of the movable claws 31A together with the first restricting member 41, and the movable claws 31A temporarily hold the fitting P2. From this state, the pair of clamp bodies 17 are brought closer to each other to finally grip the fitting P2. That is, the second clamp unit 6 temporarily grips the fitting P2 with the movable claws 31A (first-stage gripping) by the centering mechanism 30A adjusting the distance L and the positioning mechanism 33A restricting the movement of the movable claws 31A, and then, with the movement of the movable claws 31A restricted, the pair of clamp bodies 17 are brought closer to each other to finally grip the fitting P2 with the movable claws 31A (second-stage gripping). This allows the fitting P2 to be firmly gripped to withstand the thrust force during pipe joining. In addition, in the state where the movement of the movable claw 31A is restricted, even if the pair of clamp bodies 17 are brought closer to each other, the first inclined surface 41a and the second inclined surface 42a engage (wedge engagement) and the bottom surface of the second inclined member 42 presses the bottom surface of the recess 44, thereby maintaining the restriction on the movement (retraction) of the movable claw 31A abutting against the outer peripheral surface of the joint P2. Furthermore, when the pair of clamp bodies 17 are moved away from each other so as to release the grip of the joint P2 by the second clamp part 6, the biasing member 40 extends and the centering mechanism 30A adjusts the distance L to the maximum value L1.

[0034] Note that this centering mechanism 30A is based on the premise that the movable claw 31A is moved closer to the opposing surface 21 by shortening the spring member 40, thereby adjusting the distance L to be smaller. However, in order to fine-tune the contact force of the movable claw 31A against the joint P2, the pair of clamp bodies 17 may be moved away from each other while the movable claw 31A is in contact with the outer peripheral surface of the joint P2, thereby extending the spring member 40 to move the movable claw 31A in a direction away from the opposing surface 21, thereby adjusting the distance L to be larger.

[0035] 13, the piping connecting device 1A according to this embodiment includes a heater 55 for melting the open ends of the pipe P1 and the fitting P2. The heater 55 is provided so as to be able to appear and disappear between the open end of the pipe P1 held by the first clamp unit 5 and the open end of the fitting P2 held by the second clamp unit 6. That is, the heater 55 is provided so as to be able to move between a heating position B1 between the open ends of the pipe P1 and the fitting P2 and a retracted position B2 retracted from between the open ends of the pipe P1 and the fitting P2.

[0036] The heater 55 includes a heater plate 56, a first heater face 57 detachably attached to one surface of the heater plate 56, and a second heater face 58 detachably attached to the other surface of the heater plate 56. The first heater face 57 is formed in a cylindrical shape into which the open end of the pipe P1 can be inserted, and melts the outer circumferential surface of the open end of the pipe P1. Furthermore, the second heater face 58 is formed in a cylindrical shape into which the open end of the fitting P2 can be inserted, and melts the inner circumferential surface of the open end of the fitting P2.

[0037] Next, a pipe joining method using the pipe joining device 1A having the above configuration will be described. This pipe joining method includes a preparation step, a first gripping step, a pipe centering step, a second gripping step, and a pipe joining step, which will be described below.

[0038] In the preparation step, the heater plate 56 is placed at the heating position B1, and a centering jig (not shown) is used to align the centers of the second clamping part 6 and the heater plate 56 (see FIG. 9(a)). Next, the heater plate 56 is retracted from the heating position B1, and a centering jig (not shown) is used to align the centers of the second clamping part 6 and the first clamping part 5 (see FIG. 9(b)).

[0039] In the first gripping step, the first clamp unit 5 is moved close to the second clamp unit 6 (see FIG. 10(a)), and the pair of clamp bodies 13 is closed to grip the pipe P1 (see FIG. 10(b)).

[0040] In the pipe centering process, the open end of the fitting P2 is inserted into the open end of the pipe P1 held by the first clamp unit 5 (see FIG. 11(a)). This aligns the central axes O1, O2 of the pipe P1 and fitting P2. Next, the first clamp unit 5 is moved away from the second clamp unit 6 until the fitting P2 inserted into the pipe P1 abuts against the stopper 37 (see FIG. 2) (see FIG. 11(b)). This positions the fitting P2 at the reference position A of the second clamp unit 6.

[0041] In the second gripping step, the restriction on the movement of the movable claws 31A by the positioning mechanism 33A is released, and the distance L between the opposing surface 21 of the clamp body 17 and the abutment portion 35 of the movable claws 31A is set to the maximum value L1 (see FIG. 12(a)). Next, the pair of clamp bodies 17 is moved closer to each other, and it is confirmed that all of the movable claws 31A abut against the outer peripheral surface of the joint P2 (see FIG. 12(b)). At this time, each movable claw 31A is moved away from the outer peripheral surface of the joint P2 by the contraction of the biasing member 40 in accordance with the unevenness of the FRP reinforcing layer R of the joint P2, and the distance L is adjusted to a value L2 smaller than the maximum value L1. This absorbs the unevenness of the FRP reinforcing layer R of the joint P2. Next, the pair of clamp bodies 17 is moved closer to each other until the distance L becomes a value L3, which is approximately half of the maximum value (see FIG. 12(c)). Thereafter, the positioning mechanism 33A is operated to restrict the movement of the movable claw 31A that is in contact with the outer peripheral surface of the joint P2. Next, the pair of clamp bodies 17 are brought further closer to each other, so that the second clamp portion 6 grips the joint P2.

[0042] In the piping joining process, the first clamp unit 5 is moved away from the second clamp unit 6 to separate the fitting P2 and the pipe P1 (see FIG. 13(a)). Next, the protrusion of the pipe P1 is trimmed to a predetermined length. Next, a preheated heater 55 is placed at heating position B1 (see FIG. 13(b)). Thereafter, the first clamp unit 5 is brought close to the second clamp unit 6, and the fitting P2 and the pipe P1 are inserted into the respective heater faces 57 and 58 (see FIG. 14(a)). This heats and melts the open ends of the pipe P1 and the fitting P2. Next, the first clamp unit 5 is moved away from the second clamp unit 6, and the heater 55 is retracted from heating position B1 (see FIG. 14(b)). Next, the first clamp unit 5 is brought close to the second clamp unit 6, and the open ends of the pipe P1 and the fitting P2 are fused together (see FIG. 14(c)).

[0043] As described above, according to the piping connection device 1A of this embodiment, the second clamp unit 6 includes a pair of clamp bodies 17 that are movable toward and away from each other in a horizontal direction perpendicular to the movement axis M, and each of the pair of clamp bodies 17 has an opposing surface 21 that faces the outer circumferential surface of a fitting P2 disposed between the pair of clamp bodies 17 when the pair of clamp bodies 17 is brought toward each other so as to surround the outer circumferential surface of the fitting P2, and is provided with a centering mechanism 30A having movable claws 31A positioned away from the opposing surface 21 toward the fitting P2 so as to abut against the outer circumferential surface of the fitting P2. The centering mechanism 30A can freely adjust the distance L between the opposing surface 21 of the clamp body 17 and the abutment portion 35 of the movable claw 31A that abuts against the outer circumferential surface of the fitting P2 when the pair of clamp bodies 17 are brought toward each other to grip the fitting P2 with the second clamp unit 6, in order to align the central axes O1, O2 of the pipe P1 gripped by the first clamp unit 5 and the fitting P2 gripped by the second clamp unit 6. As a result, the centering mechanism 30A adjusts the distance L between the opposing surface 21 of the clamp body 17 and the abutment portion 35 of the movable claw 31A that abuts against the joint P2 in accordance with the irregularities on the outer peripheral surface of the joint P2 reinforced with fiber-reinforced plastic, thereby absorbing the irregularities on the outer peripheral surface of the joint P2 and enabling the joint P2 to be gripped without misalignment. Therefore, the central axes O1, O2 of the pipe P1 gripped by the first clamp unit 5 and the joint P2 gripped by the second clamp unit 6 can be aligned, allowing the open ends to be properly fused together.

[0044] Moreover, in this embodiment, the centering mechanism 30A includes a movable claw 31A, a movement mechanism 32A that continuously moves the movable claw 31A in a direction approaching the opposing surface 21 of the clamp body 17 when the pair of clamp bodies 17 are brought close to each other and the second clamp section 6 grips the joint P2, and a positioning mechanism 33A that restricts movement of the movable claw 31A that abuts against the outer peripheral surface of the joint 17, and the movement mechanism 32A is a biasing member 40 that biases the movable claw 17 in a direction away from the opposing surface 21. This allows the centering mechanism 30A to be configured with a simple structure. In this embodiment, the centering mechanism 30A includes a linear motion mechanism 34A that linearly moves the movable claw 31A, thereby allowing the movable claw 31A to move smoothly linearly. Furthermore, in this embodiment, the positioning mechanism 33A includes a first restricting member 41 and a second restricting member 42, and can restrict the movement of the movable claw 31A by positioning the second restricting member 42 in a state in which the first inclined surface 41a and the second inclined surface 42a are engaged by movement of the second restricting member 42. This makes it possible to easily restrict the movement of the movable claw 31A.

[0045] Next, a centering mechanism 30B according to another embodiment will be described with reference to Fig. 15. This centering mechanism 30B is provided in the second clamp unit 6 of the pipe connecting device 1A in place of the above-described centering mechanism 30A.

[0046] The centering mechanism 30B can freely adjust the distance L between the opposing surfaces 21 of the clamp bodies 17 and the contact portions 35 of the movable claws 31B that contact the outer peripheral surface of the fitting P2 when the pair of clamp bodies 17 are brought close to each other to grip the fitting P2 with the second clamp unit 6, in order to align the central axes O1, O2 of the pipe P1 gripped by the first clamp unit 5 and the fitting P2 gripped by the second clamp unit 6. The centering mechanism 30B includes the movable claws 31B, a movement mechanism 32B that continuously moves the movable claws 31B in a direction away from the opposing surfaces 21 of the clamp bodies 17 (i.e., a direction toward the fitting P2) when the pair of clamp bodies 17 are brought close to each other to grip the fitting P2 with the second clamp unit 6, a positioning mechanism 33B that restricts movement of the movable claws 31B that contact the outer peripheral surface of the fitting P2, and a linear motion mechanism 34B that linearly moves the movable claws 31B. A bracket 61 is attached to the clamp body 17.

[0047] The movable claw 31B is provided at the end of a screw 63 that is screwed into a screw hole 62 formed in the bracket 61. The movable claw 31B can be, for example, one that is supported to be rotatable around the axis of the screw 63 (see FIG. 16(a)). Specifically, a support portion 64 with a generally T-shaped cross section protrudes from the end of the screw 63, and a recess 65 with a generally T-shaped cross section formed in the movable claw 31B is supported by the support portion 64. Even when the screw 63 is screwed in with the movable claw 31B abutting the outer peripheral surface of the joint P2, the movable claw 31B does not rotate with the screw 63, and therefore does not damage the joint P2. Furthermore, the movable claw 31B can be, for example, one that is supported to be tiltable around the axis of the screw 63 (see FIG. 16(b)). Specifically, a sphere 66 protrudes from the end of the screw 63, and the sphere 66 supports a spherical recess 67 formed in the movable claw 31B. According to the present movable claw 31B, the movable claw 31B can tilt in accordance with the unevenness of the outer peripheral surface of the joint P2, thereby firmly gripping the joint P2. Note that a support pin extending in a direction perpendicular to the axis of the screw 63 may be provided on one of the end of the screw 63 and the movable claw 31B, and a pivotal support part that pivotally supports the support pin may be provided on the other, thereby employing a movable claw that is supported so as to be tiltable relative to the axis of the screw 63. Furthermore, the tip of the screw 63 may be the movable claw.

[0048] The movement mechanism 32B, the positioning mechanism 33B, and the linear motion mechanism 34B are each formed by a screw 63 and a threaded hole 62 of the bracket 61. That is, the movement mechanism 32B moves the movable claw 31B in a direction away from the opposing surface 21 by screwing the screw 63 in a state where the pair of clamp bodies 17 are brought close to each other and the movable claw 31B faces the outer circumferential surface of the joint P2. Furthermore, the positioning mechanism 33B restricts the movement of the movable claw 31B by threading the screw 63 into the screw hole 62 by stopping the screwing of the screw 63. Furthermore, the linear motion mechanism 34B linearly moves the movable claw 31B by screwing the screw 63.

[0049] The screw 63 may be automatically driven by a drive source (e.g., a pneumatic cylinder, a hydraulic cylinder, a motor, etc.) instead of being manually driven as described above. Furthermore, the screw 63 may be connected to the operating rod 72 via a gear mechanism 75 such as a bevel gear or a worm gear (see FIG. 18). This improves the operability of the screw 63.

[0050] With the second clamp unit 6 equipped with this centering mechanism 30B, the pair of clamp bodies 17 are brought closer to each other so that the movable claws 31B face the outer peripheral surface of the joint P2, and from this state, the screws 63 are screwed in so that the distance L between the opposing surfaces 21 of the clamp bodies 17 and the abutment portions 35 of the movable claws 31B increases, bringing the movable claws 31B into contact with the outer peripheral surface of the joint P2, and the positioning mechanism 33B restricts the movement of the movable claws 31B, thereby absorbing any irregularities on the outer peripheral surface of the joint P2 and temporarily gripping the joint P2 with the movable claws 31B. From this state, the pair of clamp bodies 17 are brought even closer to each other so that the movable claws 31B finally grip the joint P2.

[0051] Note that this centering mechanism 30B is based on the premise that the movable claw 31B is moved in a direction away from the opposing surface 21 by screwing in the screw 63, thereby adjusting the distance L to be larger. However, in order to fine-tune the contact force of the movable claw 31B against the joint P2, the screw 63 may be loosened while the movable claw 31B is in contact with the outer peripheral surface of the joint P2, thereby moving the movable claw 31B in a direction closer to the opposing surface 21, thereby adjusting the distance L to be smaller.

[0052] Next, a centering mechanism 30C according to still another embodiment will be described with reference to Fig. 17. This centering mechanism 30C is provided in the second clamp unit 6 of the pipe connecting device 1A instead of the above-described centering mechanism 30A.

[0053] The centering mechanism 30C can freely adjust the distance L between the opposing surfaces 21 of the clamp bodies 17 and the contact portions 35 of the movable claws 31C that contact the outer peripheral surface of the fitting P2 when the pair of clamps 17 are brought close to each other to grip the fitting P2 with the second clamp unit 6, in order to align the central axes O1, O2 of the pipe P1 gripped by the first clamp unit 5 and the fitting P2 gripped by the second clamp unit 6. The centering mechanism 30C includes the movable claws 31C, a moving mechanism 32C that continuously moves the movable claws 31C in a direction away from the opposing surfaces 21 of the clamp bodies 17 (i.e., a direction toward the fitting P2) when the pair of clamp bodies 17 are brought close to each other to grip the fitting P2 with the second clamp unit 6, a positioning mechanism 33C that restricts movement of the movable claws 31C that contact the outer peripheral surface of the fitting P2, and a linear motion mechanism 34C that linearly moves the movable claws 31C. A bracket 71 is attached to the clamp body 17.

[0054] The movable claw 31C has a triangular (or curved concave) cutout on its surface and has multiple (two in FIG. 17) contact portions 35 that contact the outer peripheral surface of the joint P2 at separate positions along the outer peripheral surface. This makes it easy to accommodate multiple sizes of joint P2 and allows for stronger contact with the outer peripheral surface of the joint P2. The number of contact portions 35 may be three or more.

[0055] The movement mechanism 32C and the positioning mechanism 33C each include a screw portion 73 formed on the tip side of an operating rod 76 and a screw hole 74 formed on the back side of the movable claw 31C into which the screw portion 73 screws. The operating rod 76 is supported by the bracket 71 so as to be rotatable about an axis along the movement direction of the movable shaft 31C. The movement mechanism 32C moves the movable claw 31C in a direction away from the opposing surface 21 by rotating the operating rod 76 in a direction to loosen the screw portion 73 while bringing the pair of clamp bodies 17 close to each other so that the movable claw 31C faces the outer circumferential surface of the joint P2. Furthermore, the positioning mechanism 33C restricts the movement of the movable claw 31C by threading the screw portion 73 into the screw hole 74 by stopping the rotation of the operating rod 76.

[0056] The rotation of the operating rod 76 may be performed automatically by driving a drive source (for example, a pneumatic cylinder, a hydraulic cylinder, a motor, etc.) instead of by manual operation as described above. Furthermore, the operating rod 76 may be connected to another operating rod 72 via a gear mechanism 75 such as a bevel gear or a worm gear (see FIG. 18). This improves the operability of the operating rod 72.

[0057] The linear motion mechanism 34C is composed of a linear motion shaft 77 attached to the back side of the movable claw 31C and a support hole 78 formed in the bracket 71 that supports the linear motion shaft 77. That is, the linear motion mechanism 34C linearly moves the movable claw 31C by supporting the linear motion shaft 77 in the support hole 78. Note that if the movable claw 31C can be linearly moved by the movement mechanism 32C alone, the linear motion mechanism 34C is not necessarily required.

[0058] With the second clamp unit 6 equipped with this centering mechanism 30C, the pair of clamp bodies 17 are brought closer to each other so that the movable claws 31C face the outer peripheral surface of the joint P2, and from this state, the screw portions 73 are loosened so that the distance L between the opposing surfaces 21 of the clamp bodies 17 and the abutment portions 35 of the movable claws 31C increases, bringing the movable claws 31C into contact with the outer peripheral surface of the joint, and the positioning mechanism 33C restricts the movement of the movable claws 31C, thereby absorbing any irregularities on the outer peripheral surface of the joint P2 and temporarily gripping the joint P2 with the movable claws 31C. From this state, the pair of clamp bodies 17 are brought even closer to each other so that the movable claws 31C finally grip the joint P2.

[0059] Note that this centering mechanism 30C is based on the premise that the screw portion 73 is loosened by rotating the operating rod 72, thereby moving the movable claw 31 in a direction away from the opposing surface 21 and adjusting to increase the distance L; however, in order to fine-tune the contact force of the movable claw 31C against the joint P2, the screw portion 73 may be screwed in by rotating the operating rod 72 while the movable claw 31B is in contact with the outer peripheral surface of the joint P2, thereby adjusting to decrease the distance L.

[0060] Next, a centering mechanism 30D according to still another embodiment will be described with reference to Fig. 19. This centering mechanism 30D is provided in the second clamp unit 6 of the pipe connecting device 1A instead of the above-described centering mechanism 30A.

[0061] The centering mechanism 30D can freely adjust the distance L between the opposing surfaces 21 of the clamp bodies 17 and the contact portions 35 of the movable claws 31D that abut against the outer circumferential surface of the fitting P2 when the pair of clamp bodies 17 are brought close to each other to grip the fitting P2 with the second clamp unit 6, in order to align the central axes O1, O2 of the pipe P1 gripped by the first clamp unit 5 and the fitting P2 gripped by the second clamp unit 6. The centering mechanism 30D includes the movable claws 31D, a movement mechanism 32D that continuously moves the movable claws 31D in a direction approaching the opposing surfaces 21 of the clamp bodies 17 when the pair of clamp bodies 17 are brought close to each other to grip the fitting P2 with the second clamp unit 6, a positioning mechanism 33D that restricts movement of the movable claws 31D that abut against the outer circumferential surface of the fitting P2, and a linear motion mechanism 34D that linearly moves the movable claws 31D. A bracket 81 is attached to the clamp bodies 17.

[0062] The movement mechanism 32D is a biasing member 82 (e.g., a coil spring, a fluid spring, or the like) that biases the movable claw 31D in a direction away from the opposing surface 21 of the clamp body 17 (i.e., in a direction toward the joint P2). When the pair of clamp bodies 17 are brought toward each other and the second clamp unit 6 grips the joint P2, the abutment portion 35 of the movable claw 31D abuts against the biasing force of the biasing member 82 and the biasing member 82 contracts, thereby continuously moving the movable claw 31D in a direction toward the opposing surface 21. Note that a plurality of biasing members 82 (two in FIG. 19 ) are arranged between the movable claw 31D and the bracket 81. Specifically, the biasing members 82 are arranged on both sides of the movable claw 31D in the longitudinal direction.

[0063] The positioning mechanism 33D is composed of a screw hole 83 formed in the bracket 81 and a screw 84 that is screwed into the screw hole 83. That is, the positioning mechanism 33D restricts the movement of the movable claw 31D by bringing the tip of the screw 84 into contact with the movable claw 31D.

[0064] The screw 84 may be screwed in manually or automatically by driving a drive source (for example, a pneumatic cylinder, a hydraulic cylinder, a motor, etc.). Furthermore, the screw 84 may be connected to the operating rod 72 via a gear mechanism 75 such as a bevel gear or a worm gear (see FIG. 18). This improves the operability of the screw 84.

[0065] The linear motion mechanism 34D is made up of a linear motion shaft 85 attached to the back surface side of the movable claw 31D and a support hole 86 formed in the bracket 81 that supports the linear motion shaft 85. That is, the linear motion mechanism 34D linearly moves the movable claw 31D by supporting the linear motion shaft 85 in the support hole 86.

[0066] With the second clamp unit 6 equipped with this centering mechanism 30D, by bringing the pair of clamp bodies 17 closer to each other and bringing the movable claws 31D into contact with the outer peripheral surface of the joint P2, the biasing member 82 is shortened, adjusting the distance L between the opposing surface 21 of the clamp body 17 and the contact portion 35 of the movable claw 31D to be smaller, and by screwing the screw 84 of the positioning mechanism 33D into contact with the movable claws 31D and restricting the movement of the movable claws 31D, unevenness on the outer peripheral surface of the joint P2 is absorbed and the movable claws 31D temporarily hold the joint P2. From this state, by bringing the pair of clamp bodies 17 even closer to each other, the movable claws 31D finally grip the joint P2.

[0067] Next, a centering mechanism 30E according to yet another embodiment will be described with reference to Figure 20. This centering mechanism 30E is provided in the second clamp unit 6 of the pipe connecting device 1A instead of the above-mentioned centering mechanism 30A. Furthermore, in this centering mechanism 30E, parts having the same configuration as the above-mentioned centering mechanism 30D are designated by the same reference numerals and detailed description thereof will be omitted.

[0068] The centering mechanism 30E can freely adjust the distance L between the opposing surfaces 21 of the clamp bodies 17 and the contact portions 35 of the movable claws 31D that abut against the outer peripheral surface of the fitting P2 when the pair of clamp bodies 17 are brought close to each other to grip the fitting P2 with the second clamp unit 6, in order to align the central axes O1, O2 of the pipe P1 gripped by the first clamp unit 5 and the fitting P2 gripped by the second clamp unit 6. The centering mechanism 30E includes the movable claws 31D, a movement mechanism 32D that continuously moves the movable claws 31D toward the opposing surfaces 21 of the clamp bodies 17 when the pair of clamp bodies 17 are brought close to each other to grip the fitting P2 with the second clamp unit 6, a positioning mechanism 33E that restricts movement of the movable claws 31D that abut against the outer peripheral surface of the fitting P2, and a linear motion mechanism 34D that linearly moves the movable claws 31D. A bracket 87 is attached to the clamp bodies 17.

[0069] The positioning mechanism 33E is composed of an eccentric cam 88 that is provided on a bracket 87 so as to be rotatable and positionable in a direction perpendicular to the movement direction of the movable claw 31D. That is, the positioning mechanism 33E rotates the eccentric cam 88 to position it, and restricts the movement of the movable claw 31D by bringing the eccentric cam 88 into contact with the movable claw 31D. The rotation of the eccentric cam 88 may be performed manually or automatically by being driven by a drive source (for example, a pneumatic cylinder, a hydraulic cylinder, a motor, etc.).

[0070] Next, a second clamp unit 90 according to another embodiment will be described with reference to FIG. 21. This second clamp unit 90 includes a pair of clamp bodies 91 that are movable toward and away from each other on a plane perpendicular to the movement axis M. The lower clamp body 91 is fixed to the second base 3, and the upper clamp body 91 is provided so as to be swingable about an axis parallel to the movement axis M. The pair of clamp bodies 91 move toward and away from each other by swinging the upper clamp body 91 relative to the lower clamp body 91. The swinging of the upper clamp body 91 may be performed manually by operating an operating lever 92, or may be automatically swung by a drive source (e.g., a pneumatic cylinder, a hydraulic cylinder, a motor, etc.).

[0071] Each of the pair of clamp bodies 91 has an opposing surface 21 that faces the outer peripheral surface of the joint P2 that is positioned between the pair of clamp bodies 91 when the pair of clamp bodies 91 are brought close to each other, and surrounds the outer peripheral surface of the joint P2. Also, a plurality of centering mechanisms 30D (three in the figure) are provided, each having movable claws 31D that are positioned away from the opposing surface 21 toward the joint P2 so as to abut against the outer peripheral surface of the joint P2. The opposing surface 21 is formed in an arc shape that is larger than the outer diameter of the joint. The centering mechanism provided in this clamp body 91 can be selected, for example, from the above-mentioned centering mechanisms 30A to 30E.

[0072] Next, a pipe connecting device 1B according to another embodiment will be described with reference to Fig. 22. In this pipe connecting device 1B, parts having substantially the same configuration as those in the above-described pipe connecting device 1A will be assigned the same reference numerals and detailed description thereof will be omitted.

[0073] This piping connection device 1B uses a socket to fuse the open ends of a resin FRP-reinforced pipe P1 (exemplified as the "first piping member" of the present invention) and a resin FRP-reinforced joint P2 (exemplified as the "second piping member" of the present invention). Note that the outer circumferential surface of the open end of the pipe P1 is not reinforced with FRP.

[0074] This piping connection device 1B comprises a first base 2 and a second base 3 that can move toward and away from each other along a movement axis M, a first clamp unit 95 that is provided on the first base 2 and holds the pipe P1 so that its central axis O1 extends parallel to the movement axis M, and a second clamp unit 6 that is provided on the second base 3 and holds the fitting P2 so that its central axis O2 extends parallel to the movement axis M.

[0075] The first clamp section 95 has a pair of clamp bodies 17 that can be opened and closed in a horizontal direction (i.e., width direction) perpendicular to the movement axis M. A plurality of pairs of clamp bodies 17 (two pairs in FIG. 1) are provided at intervals in the direction of the movement axis M. Each of the plurality of pairs of clamp bodies 17 is provided with a centering mechanism 30A.

[0076] The pipe joining method using the present pipe joining apparatus 1B is the same as the pipe joining method using the pipe joining apparatus 1A except for the pipe centering step. The pipe centering step is performed using a centering jig 96. The centering jig 96 includes a cylindrical first holding portion 97 into which the open end of the pipe P1 can be inserted and a second holding portion 98 connected to the axial end of the first holding portion 97 and insertable into the open end of the fitting P2. The open end of the pipe P1 gripped by the first clamp unit 5 is inserted into the first holding portion 97, and then the second holding portion 98 is inserted into the open end of the fitting P2, thereby aligning the pipe P1 and the fitting P2. The centering jig 96 allows proper alignment of the fitting P2, whose inner periphery is tapered, with the pipe P1. Furthermore, the present pipe joining apparatus 1B can grip the FRP-reinforced pipe P1 without misalignment, and can grip the FRP-reinforced fitting P2 without misalignment. In this embodiment, an example is given of a form in which the outer surface (outer diameter) of the open end of the pipe P1 is inserted into the cylindrical first retaining portion 97 to align the first retaining portion 97 with the pipe P1 (see Figure 22), but this is not limited to this, and for example, a convex-shaped first retaining portion 97 may be inserted into the inner surface (inner diameter) of the open end of the pipe P1 to align the first retaining portion 97 with the pipe P1.

[0077] The present invention is not limited to the above-described embodiment, and various modifications may be made within the scope of the present invention based on the purpose and application. That is, in the pipe connecting device 1A of the above-described embodiment, the centering mechanism 30A is provided with the movable claw 31A having one abutment portion 35 that abuts on the outer peripheral surface of the fitting P2, but the present invention is not limited to this. For example, the centering mechanism 30A may be provided with the movable claw 31A having multiple abutment portions 35 that abut on the outer peripheral surface of the fitting P2 at spaced positions along the outer peripheral surface.

[0078] Furthermore, in the above-described embodiment of the pipe connecting device 1A, a centering mechanism 30A in which the movable claw 31A cannot tilt relative to an axis along its movement direction is exemplified, but this is not limited to this, and the centering mechanism 30A may, for example, be one in which the movable claw 31A can tilt relative to an axis along its movement direction.

[0079] Furthermore, in the above-described embodiment of the pipe connecting device 1A, a centering mechanism 30A including a positioning mechanism 33A having a first regulating member 41 and a second regulating member 42 is exemplified, but this is not limited to this, and the centering mechanism 30A may also include, for example, a positioning mechanism 33D formed by a screw hole 83 and a screw 84 in a bracket 81, or a positioning mechanism 33E formed by an eccentric cam 88.

[0080] Furthermore, in the above-described embodiment of the piping connection device 1A, the second clamp section 6 is exemplified as having four centering mechanisms 30A, but this is not limited to this, and the second clamp section 6 may be, for example, having three or five or more centering mechanisms 30A.

[0081] Furthermore, in the above-described embodiment, the pipe connecting device 1A exemplifies a configuration in which the open ends of the pipe P1 and the fitting P2 are fused together using a socket method. However, this is not limited to this. For example, the pipe connecting device 1A may bond the open ends of the pipe P1 and the fitting P2 together by applying an adhesive to the outer circumferential surface of the open end of the pipe P1. Furthermore, the pipe connecting device 1A may also be configured to butt the axial end faces of the open ends of a pair of piping components P1 and P2 together and fuse them together. The socket connection of the open ends of the pipe P1 and the fitting P2 can be performed based on, for example, Japanese Industrial Standards (JIS K6741, K6777), American Society for Testing and Materials Standard (ASTM D1785), German Industrial Standard (DIN8062), etc. [Industrial Applicability]

[0082] INDUSTRIAL APPLICABILITY The present invention is widely used as a technique for joining open ends of first and second resin piping members by aligning their central axes. [Explanation of symbols]

[0083] 1A, 1B; Pipe connecting device, 2; First base, 3; Second base, 5; First clamp portion, 6; Second clamp portion, 17; Pair of clamp bodies, 21; Opposing surfaces of clamp bodies, 30A-30E; Centering mechanism, 31A-31D; Movable claws (movable grippers), 32A-32D; Moving mechanism, 33A-33E; Positioning mechanism, 34A-34D; Linear motion mechanism, 35; Contact portion, 40; Pressing member, 41; First regulating member, 41a; First inclined surface, 42; Second regulating member, 42a; Second inclined surface, P1; Pipe, P2; Fitting, L; Distance, M; Movement axis.

Claims

1. a first clamping unit provided on the first base and a second base that is movable toward and away from each other along a movement axis; a first clamping unit that is provided on the first base and that holds a first resin piping member so that its central axis extends parallel to the movement axis; and a second clamping unit that is provided on the second base and that holds a second resin piping member so that its central axis extends parallel to the movement axis, wherein the first base and the second base are brought close to each other to join open ends of the first piping member held by the first clamping unit and the second piping member held by the second clamping unit, At least one of the first clamp portion and the second clamp portion includes a pair of clamp bodies that are movable toward and away from each other on a plane perpendicular to the movement axis, Each of the pair of clamp bodies has an opposing surface that faces the outer peripheral surface of one of the piping members disposed between the pair of clamp bodies when the pair of clamp bodies are brought close to each other, and surrounds the outer peripheral surface of the one of the piping members. A centering mechanism is also provided, which has a movable gripper that is disposed at a position away from the opposing surface toward the one of the piping members so as to abut against the outer peripheral surface of the one of the piping members. the centering mechanism includes the movable gripper, a moving mechanism that moves the movable gripper in a stepless manner in a direction approaching the opposing surface when the pair of clamp bodies are brought close to each other to grip the one piping member with the one clamp portion, and a positioning mechanism that restricts movement of the movable gripper that abuts against the outer peripheral surface of the one piping member, the moving mechanism is a biasing member that biases the movable gripper in a direction away from the opposing surface, The centering mechanism is a piping connecting device characterized in that when the pair of clamp bodies are brought close to each other to grip one of the piping members with one of the clamp sections, in order to align the central axes of the first piping member gripped by the first clamp section and the second piping member gripped by the second clamp section, the centering mechanism can adjust the distance (L) between the opposing surfaces of the clamp bodies and the abutment portion of the movable gripper abutting the outer surface of the one of the piping members by shortening the biasing member as the pair of clamp bodies approach each other.

2. A piping joining device as described in claim 1, in which the distance (L) between the clamp body and the movable gripper is adjusted to be small by shortening the biasing member, and the movement of the movable gripper is restricted by the positioning mechanism, thereby provisionally gripping the one piping component with one of the clamp portions, and the pair of clamp bodies is brought even closer to each other from this provisional gripping state, thereby permanently gripping the one piping component with one of the clamp portions.

3. The pipe connecting device according to claim 1 or 2, wherein the centering mechanism includes a linear motion mechanism that linearly moves the movable gripper.

4. A piping joining device as described in Claim 3, wherein the linear motion mechanism has a bush or support hole provided in the clamp body, and a linear motion shaft guided in a linear manner by the bush or support hole.

5. 5. The piping connecting device according to claim 1, wherein the positioning mechanism comprises: a first restricting member attached to the movable gripper and having a first inclined surface inclined with respect to the movement direction of the movable gripper; and a second restricting member provided on the clamp body so as to be movable and positionable in a direction perpendicular to the movement direction of the movable gripper and having a second inclined surface inclined with respect to the movement direction of the movable gripper and engageable with the first inclined surface; and the second restricting member is positioned in a state in which the first inclined surface and the second inclined surface are engaged by movement of the second restricting member, thereby restricting movement of the movable gripper.

6. the centering mechanism includes a linear motion mechanism that linearly moves the movable gripper, 2. The piping connecting device according to claim 1, wherein the positioning mechanism comprises: a first restricting member attached to the movable gripper and having a first inclined surface inclined with respect to the movement direction of the movable gripper; and a second restricting member provided on the clamp body so as to be movable and positionable in a direction perpendicular to the movement direction of the movable gripper and having a second inclined surface inclined with respect to the movement direction of the movable gripper and engageable with the first inclined surface, wherein the movement of the second restricting member is engaged with the first inclined surface, and the second restricting member is positioned to restrict the movement of the movable gripper.

7. 7. The pipe connecting device according to claim 1, wherein at least one of the first piping member and the second piping member is a pipe or a joint reinforced with fiber-reinforced plastic.

8. A piping joining device as described in Claim 7, wherein the pipe or the fitting is reinforced by spirally wrapping tape-like fiber-reinforced plastic around the outer surface while partially overlapping it.

9. The pipe connecting device according to any one of claims 1 to 8, wherein open ends of the first pipe member and the second pipe member are connected to each other by a socket type.

10. 10. The pipe connecting device according to claim 1, wherein the first pipe member and the second pipe member are made of polyvinyl chloride, polyethylene, polypropylene, or polyvinylidene fluoride.

11. The pipe connecting device according to claim 1 , further comprising a heater for melting each of the open ends of the first pipe member and the second pipe member.

12. A pipe joining method, comprising joining open ends of a first pipe member and a second pipe member together using the pipe joining device according to any one of claims 1 to 11.

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