JP7824132B2 - Pipe joining device and pipe joining method - Google Patents

Description

The present invention relates to a pipe joining device and a pipe joining method for joining the open ends of a pair of resin pipe members.

Pipe joining devices for joining the open ends of a pair of resin piping components, such as pipes and fittings, are commonly known. Such pipe joining devices often include a first base and a second base that can move toward and away from each other along a movement axis; a first clamping unit mounted on the first base and holding the first resin piping component with its central axis extending parallel to the movement axis; and a second clamping unit mounted on the second base and holding the second resin piping component with its central axis extending parallel to the movement axis. In this configuration, during joining, the central axes of the first piping component held by the first clamping unit and the second piping component held by the second clamping 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 components. The open ends of the first and second piping members can be joined together by any suitable method, such as welding each open end by melting it with a heater, or by applying an adhesive to the outer periphery of the open end of one of the piping members.

The above-mentioned clamping unit typically includes a pair of clamp bodies that sandwich a piping member and can move toward and away from each other horizontally, as described in Patent Document 1, for example. In such clamping units, the pair of clamp bodies are brought toward each other so that roughly triangular notches formed on each clamp body come into contact with the outer peripheral surface of the piping member, thereby gripping the piping member.

JP 2013-216046 A

Piping plants sometimes use piping components reinforced with fiber-reinforced plastic (hereinafter also referred to as "FRP"). Stress concentration is particularly likely to occur at elbow-type and cheese-type joints, making it desirable to use joints reinforced with FRP to reinforce joints and bends. Piping components reinforced with FRP are obtained, for example, by spirally wrapping tape-like FRP around the outer surface of a piping component, 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.

However, the clamping units described above grip the piping component by bringing a pair of clamp bodies close to each other and abutting the approximately triangular notches formed on each clamp body against the outer periphery of the piping component. Therefore, when gripping a piping component reinforced with FRP, the clamping units are unable to absorb the irregularities in the FRP reinforcing layer, and the piping component may be gripped misaligned. Therefore, in a pipe joining device equipped with the clamping units described above, the central axes of the piping components gripped by each clamping unit cannot be aligned, resulting in misalignment (e.g., a misalignment of approximately 1 to 2 mm). This misalignment can easily lead to installation defects (e.g., leaks, disconnections, breakage, etc.).
In order 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 large number of steps.

The present invention was made in consideration of the above-mentioned 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 and second piping members and properly join the open ends of the first and second piping members, even when at least one of the first and second piping members made of resin is a piping member reinforced with fiber-reinforced plastic.

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 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 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 piping connecting device described in 1 above, wherein the centering mechanism comprises the movable gripper, a movement mechanism that continuously moves the movable gripper in at least one of a direction toward and a direction away from 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 part, and a positioning mechanism that restricts movement of the movable gripper that is in contact with the outer peripheral surface of the one piping member.
3. The pipe connecting device according to 2. above, wherein the centering mechanism includes a linear motion mechanism that linearly moves the movable gripper.
4. The pipe connecting device according to 2. or 3. above, wherein the movement mechanism is a biasing member that biases the movable gripper in a direction away from the opposing surface.
5. The piping connecting device described in 4. above, 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 wherein the movement of the movable gripper can be restricted 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.
6. The centering mechanism includes the movable gripper, a movement mechanism that continuously moves the movable gripper 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, a positioning mechanism that restricts movement of the movable gripper that abuts against 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 includes 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 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.
7. The pipe connecting device according to any one of 1. to 6., 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. The pipe connecting device according to any one of 1. to 7., wherein the open ends of the first pipe member and the second pipe member are connected to each other in a socket manner.
9. The pipe connecting device according to any one of 1. to 8., 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., 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 together using the pipe joining device according to any one of 1. to 10.

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 axis of movement, 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 positioned away from the opposing surface toward the one of the piping members so as to abut 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 to grip one of the piping members, in order 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.

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 comprises 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 opening ends of the first piping member and the second piping member are joined together using a socket method, the opening ends of the first and second piping members are joined together by inserting the opening end of one piping member into the opening 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 relatively inexpensive and easily available material 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.

The present invention is further described in the following detailed description by way of non-limiting examples of exemplary embodiments according to the present invention and with reference to the referenced drawings, in which like reference numerals refer to like parts throughout the several views of the drawings.

FIG. 2 is a side view of the pipe connecting device of the present embodiment. FIG. 2 is an enlarged view of a main part of FIG. 1 . FIG. 3 is an enlarged view of the arrow III in FIG. 2 . FIG. 4 is an enlarged view of the main part of FIG. 3 with the set screw removed. 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. FIG. 4 is an enlarged view of a main part of FIG. 3, showing a cross section of the base member. FIG. 2 is a perspective view of a clamp body equipped with the centering mechanism of the present embodiment. FIG. 2 is an exploded perspective view of the centering mechanism of the present embodiment. 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. 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. 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. 1A and 1B 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 movable claw temporarily grips the joint. 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. 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 have been removed from the heater, and (c) shows a state in which the fitting and the pipe have been fused together. 10A and 10B are explanatory views for explaining a centering mechanism according to another embodiment, in which FIG. 10A is a front view and FIG. 16A and 16B are enlarged cross-sectional views of a portion of the main part of FIG. 15, in which (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. 10A and 10B are explanatory views for explaining a centering mechanism according to still another embodiment. 10A and 10B are explanatory views for explaining a centering mechanism according to still another embodiment. 10A and 10B are explanatory views for explaining a centering mechanism according to still another embodiment. 10A and 10B are explanatory views for explaining a centering mechanism according to still another embodiment. 10A and 10B are explanatory views for explaining a second clamping portion according to another embodiment. 10A and 10B are explanatory diagrams for explaining another embodiment of a pipe joining device, in which (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.

The matters set forth herein are for illustrative purposes only and are intended to provide an illustrative description of embodiments of the present invention, with the objective of providing what is believed to be the most effective and readily 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 those necessary for a fundamental understanding of the present invention, and the description, taken in conjunction with the drawings, will make clear to those skilled in the art how some aspects of the present invention may be implemented in practice.

The present invention will be described in detail below with reference to the drawings and embodiments. This embodiment illustrates a pipe connection device 1A that uses a socket-type fusion welding (including contact and non-contact welding) to bond 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) (see FIG. 1). Specifically, this pipe connection 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 fitting P2 are made of polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP), or polyvinylidene fluoride (PVDF) for ultrapure water. However, the pipe P1 and fitting P2 may also be made of chlorinated polyvinyl chloride (PVC-C), acrylonitrile butadiene styrene resin (ABS resin), perfluoroalkoxyalkane (PFA), polyphenylene sulfide (PPS), etc.

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 types of the first and second piping members include pipes (straight pipes, curved pipes, etc.), joints (elbow, tee, bend, socket, etc.), caps, flanges, etc. These first and second piping members may be of different types or the same type. Examples of FRP reinforcement forms for the first and second piping members include a form in which only one piping member is reinforced with FRP, or a form in which both piping members are reinforced with FRP. Furthermore, uses of the first and second piping members include, for example, ultrapure water used in semiconductor manufacturing, general use, tap water, agricultural water, plant piping, and heat-resistant uses such as hot water.

As shown in Figure 1, the piping connection device 1A according to this embodiment comprises 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 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 that holds the fitting P2 so that its central axis O2 extends parallel to the movement axis M. Note that Figures 1 to 3 show the 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, aligning the pipe P1 and the fitting P2.

The first base 2 and the second base 3 are movable toward and away from each other along the movement axis M by a guide device 9, such as a guide rail, mounted on a platform 8 installed on the floor. By manually rotating an operating handle 11 mounted 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 movement of the first base 2 and the second base 3 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.

The top surfaces of the first base 2 and the second base 3 are formed with flat table surfaces 2a, 3a that extend 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 grips 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 grips 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 closest to the second base 3 should be inserted, coincides with the central axis O1 of the open end of the pipe P1 gripped by the first clamp unit 5.

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 Figure 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 mounting bases 14 provided on the table surface 2a of the first base 2 so that they face each other. The pair of clamp mounting bases 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 mounting bases 14, a single 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 mounts 14 are opened and closed is not particularly limited, and instead of being opened and closed manually as described above, the pair of clamp mounts 14 may be opened and closed automatically, for example, by driving a drive source (e.g., pneumatic cylinder, hydraulic cylinder, motor, etc.).

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

The second clamp unit 6 includes a pair of clamp bodies 17 that can move 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 mounting bases 18 (not shown) provided on the table surface 3a of the second base 3 so as to face each other. The pair of clamp mounting bases 18 are guided by guide rails (not shown) to open and close horizontally perpendicular to the movement axis M on the table surface 3a by manual operation of an operating handle 19 provided on the second base 3. As the pair of clamp mounting bases 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 towards or away from each other by driving a drive source (e.g., pneumatic cylinder, hydraulic cylinder, motor, etc.).

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. For example, it may be a movable claw made of metal or resin, a rubber device that elastically deforms to come into contact with the outer surface of the piping member, or a suction cup device that adheres to the outer surface of the piping member.

As shown in Figures 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 positioned between the pair of clamp bodies 17 when the pair of clamp bodies 17 are brought close to each other. The pair of clamp bodies 17 have identical isosceles trapezoidal notches 22 at the same height in their central portions. The surfaces of these notches 22 that face the outer peripheral surface of the joint P2 form the opposing surface 21. This opposing surface 21 has a flat surface 21a that extends vertically and a flat surface 21b that is connected to the upper and lower ends of flat surface 21a and extends in a direction inclined relative to the vertical direction. Flat surface 21a faces horizontally relative to the outer peripheral surface of the joint P2, while flat surface 21b faces in a direction inclined relative to the outer peripheral surface of the joint P2. However, the shape of the notch 22 is not particularly limited, and in addition to the isosceles trapezoidal shape described above, other shapes such as a triangle, semicircle, or arc 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 of the pair of clamp bodies 17, and a rib plate 24 extending in the vertical direction is attached. A cover member 25 is attached to the front surface 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.

Each of the pair of clamp bodies 17 is provided with a centering mechanism 30A that includes one movable claw 31A positioned away from the opposing surface 21 of the clamp body 17 toward joint P2 so that it abuts the outer peripheral surface of joint P2 when the pair of clamp bodies 17 are brought close to each other. Each of the pair of clamp bodies 17 is provided with multiple centering mechanisms 30A (two in Figure 3). Furthermore, the centering mechanism 30A is positioned corresponding to the flat surface 21b of 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 body 6 grips the fitting P2, the centering mechanism 30A can freely adjust the diametric distance L of the fitting P2 (i.e., the amount of protrusion (extension) of the movable claw 31A from the opposing surface 21) 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 when the pair of clamp bodies 17 are brought close to each other and the fitting P2 is gripped by the second clamp body 6 to align the central axes O1, O2 of the pipe P1 gripped by the first clamp body 5 and the fitting P2 gripped by the second clamp body 6 (see Figure 12).

As shown in Figures 4 to 6, the centering mechanism 30A includes a movable claw 31A, a movement mechanism 32A that continuously moves the movable claw 31A toward the opposing surface 21 of the clamp body 17 when the pair of clamp bodies 17 are brought toward each other to grip the joint P2 with the second clamp section 6, a positioning mechanism 33A that restricts the movement of the movable claw 31A that abuts against the outer peripheral surface of the joint P2, and a linear motion mechanism 34A that linearly moves the movable claw 31A.

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

The moving mechanism 32A is a biasing member 40 (e.g., a coil spring, fluid spring, etc.) that biases the movable claw 31A in a direction away from the opposing surface 21 of the clamp body 17 (i.e., toward the joint P2). When the pair of clamp bodies 17 are brought close to each other and the second clamp section 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 toward the opposing surface 21 (see Figure 12). The biasing member 40 also biases the movable claw 31A toward the central axis O2 of the joint P2. The biasing member 40 is disposed between the bottom surface of the support hole 39 in the base member 23 and the stepped portion 38a of the moving shaft 38. When the biasing member 40 is in its most extended state (i.e., its 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 Figure 12(a)). In this embodiment, the adjustment range for distance L is approximately 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.

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 relative to the direction of movement of the movable claw 31A, and a second restricting member 42 (also referred to as a "tapered block") mounted on the clamp body 17 so as to be movable and positionable in a direction perpendicular to the direction of movement of the movable claw 31A and having a second inclined surface 42a inclined relative to the direction of movement of the movable claw 31A and engageable with the first inclined surface 41a (see Figure 5). This positioning mechanism 33A can restrict the movement of the movable claw 31A by positioning the second restricting member 42 while engaging the first inclined surface 41a with the second inclined surface 42a by moving the second restricting member 42.

The first restricting member 41 is attached to the back side 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 back side 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 movable within the recess 44 along its elongated direction. An insertion hole 45, connected to 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, connected to the recess 44 and narrower than the recess 44, is formed on the surface side of the cover member 25. This 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 this elongated hole 46. By operating this positioning screw 47 to move the second restricting member 42, the first inclined surface 41a and the second inclined surface 42a can be engaged and disengaged. Furthermore, by threading 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, thereby positioning the second restricting member 42.

In addition, the positioning mechanism 33A may be automatically operated by a drive source (e.g., a pneumatic cylinder, a hydraulic cylinder, a motor, etc.) rather than by manual operation as described above. In this case, for example, the second restricting member 42 can be moved in a direction perpendicular to the movement direction of the movable claw 31A by driving the drive source, and the second restricting member 42 can be positioned by stopping the drive source.

The linear motion mechanisms 34A are arranged on both longitudinal sides of the movable claw 31A, sandwiching the biasing member 40 (see Figure 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 side 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 protruding toward the movable claw 31A. The linear motion mechanism 34A may use, in addition to the linear bushing described above, an oil-free bushing or linear guide, for example. Furthermore, if the movable claw 31A can be linearly moved using only the biasing member 40, the linear motion mechanism 34A is not necessarily required.

In the second clamping section 6, 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 maximum value L1 (see FIG. 12(a)). By bringing the pair of clamping bodies 17 closer together and abutting the movable claw 31A against the outer peripheral surface of joint P2, the biasing member 40 shortens to absorb irregularities in the FRP reinforcing layer R of joint P2, and the centering mechanism 30A adjusts the distance L to a value L2 smaller than maximum value L1 (see FIG. 12(b)). Furthermore, by bringing the pair of clamping bodies 17 even closer together from this state, the centering mechanism 30A adjusts the distance L to a value L3 (e.g., approximately 5 mm) smaller than 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 temporarily holding the fitting P2 with the movable claws 31A. From this state, the pair of clamp bodies 17 are further moved 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 moved 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. Furthermore, when 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 against the bottom surface of the recess 44, maintaining the restriction on the movement (retraction) of the movable claw 31A abutting the outer peripheral surface of the joint P2. Furthermore, when the pair of clamp bodies 17 are moved away from each other 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.

Note that this centering mechanism 30A is based on the premise that the biasing member 40 is shortened to move the movable claw 31A closer to the opposing surface 21, thereby adjusting to reduce distance L. However, to fine-tune the contact force of the movable claw 31A against 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 circumferential surface of joint P2, thereby extending the biasing member 40 to move the movable claw 31A away from the opposing surface 21, thereby adjusting to increase distance L.

As shown in FIG. 13, the piping connection device 1A according to this embodiment is equipped with a heater 55 for melting the open ends of the pipe P1 and the fitting P2. This heater 55 is provided so that it can 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 that it can move between a heating position B1 between the open ends of the pipe P1 and the fitting P2 and a retracted position B2, where it is retracted from between the open ends of the pipe P1 and the fitting P2.

The heater 55 includes a heater plate 56, a first heater face 57 removably attached to one surface of the heater plate 56, and a second heater face 58 removably attached to the other surface of the heater plate 56. The first heater face 57 is formed in a cylindrical shape so that the open end of the pipe P1 can be inserted into it, 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 so that it can be inserted into the open end of the fitting P2, and melts the inner circumferential surface of the open end of the fitting P2.

Next, we will explain the pipe joining method using the pipe joining device 1A configured as described above. This pipe joining method includes the following steps: preparation step, first gripping step, pipe centering step, second gripping step, and pipe joining step.

In the preparation process, the heater plate 56 is placed at the heating position B1, and a centering jig (not shown) is used to align the second clamp portion 6 with the heater plate 56 (see Figure 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 second clamp portion 6 with the first clamp portion 5 (see Figure 9(b)).

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

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 Figure 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 Figure 2) (see Figure 11(b)). This positions the fitting P2 at the reference position A of the second clamp unit 6.

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 toward each other, and it is confirmed that all of the movable claws 31A abut 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 response to the irregularities in the FRP reinforcing layer R of the joint P2, and the distance L is adjusted to a value L2, which is smaller than the maximum value L1. This absorbs the irregularities in the FRP reinforcing layer R of the joint P2. Next, the pair of clamp bodies 17 is moved further toward each other until the distance L reaches a value L3, which is approximately half the maximum value (see FIG. 12(c)). The positioning mechanism 33A is then operated to restrict the movement of the movable claw 31A, which is in contact with the outer circumferential surface of the joint P2. The pair of clamp bodies 17 are then brought closer together, causing the second clamp portion 6 to grip the joint P2.

In the piping joining process, the first clamp 5 is separated from the second clamp 6 to separate the fitting P2 and the pipe P1 (see Figure 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 Figure 13(b)). The first clamp 5 is then brought close to the second clamp 6, and the fitting P2 and the pipe P1 are inserted into the respective heater faces 57 and 58 (see Figure 14(a)). This heats and melts the open ends of the pipe P1 and the fitting P2. Next, the first clamp 5 is separated from the second clamp 6, and the heater 55 is retracted from heating position B1 (see Figure 14(b)). Next, the first clamp 5 is brought close to the second clamp 6, and the open ends of the pipe P1 and the fitting P2 are fused together (see Figure 14(c)).

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. Each of the pair of clamp bodies 17 has an opposing surface 21 that faces the outer peripheral surface of the fitting P2 positioned between the pair of clamp bodies 17 when the pair of clamp bodies 17 is brought toward each other, surrounding the outer peripheral surface of the fitting P2. A centering mechanism 30A is also provided, which has a movable claw 31A positioned away from the opposing surface 21 toward the fitting P2 so as to abut against the outer peripheral 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 abutting the outer peripheral 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 contact portion 35 of the movable claw 31A that contacts the fitting P2 in accordance with the irregularities on the outer surface of the fitting P2, which is reinforced with fiber-reinforced plastic. This absorbs the irregularities on the outer surface of the fitting P2 and allows the fitting 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 fitting P2 gripped by the second clamp unit 6 can be aligned, allowing the open ends to be properly fused together.

In addition, in this embodiment, 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 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 moving 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 enabling the movable claw 31A to move smoothly in a linear motion.
Furthermore, in this embodiment, the positioning mechanism 33A includes a first restricting member 41 and a second restricting member 42, and can restrict movement of the movable claw 31A by positioning the second restricting member 42 in a state in which the first inclined surface 41 a and the second inclined surface 42 a are engaged by movement of the second restricting member 42. This makes it possible to easily restrict movement of the movable claw 31A.

Next, a centering mechanism 30B according to another embodiment will be described using Figure 15. This centering mechanism 30B is provided in the second clamp unit 6 of the pipe connecting device 1A in place of the centering mechanism 30A described above.

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 abut 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., in 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 abut 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.

The movable claw 31B is provided at the end of a screw 63 that threads into a threaded hole 62 formed in the bracket 61. The movable claw 31B can be, for example, supported to rotate freely around the axis of the screw 63 (see Figure 16(a)). Specifically, a support portion 64 with a generally T-shaped cross section protrudes from the end of the screw 63, and the support portion 64 supports a generally T-shaped recess 65 formed in the movable claw 31B. 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, thereby preventing damage to the joint P2. Furthermore, the movable claw 31B can be, for example, supported to tilt freely around the axis of the screw 63 (see Figure 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. The movable claw 31B can tilt in accordance with the irregularities on the outer peripheral surface of the joint P2, thereby firmly gripping the joint P2. Alternatively, a support pin extending perpendicular to the axis of the screw 63 may be provided on one side of the end of the screw 63 or the movable claw 31B, and a support part for supporting the support pin may be provided on the other side, resulting in 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 also be used as the movable claw.

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

In addition, the screw 63 may be automatically driven by a drive source (e.g., a pneumatic cylinder, a hydraulic cylinder, a motor, etc.) rather than by manual operation 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 Figure 18). This improves the operability of the screw 63.

With the second clamp unit 6 equipped with this centering mechanism 30B, the pair of clamp bodies 17 are brought closer together so that the movable claws 31B face the outer peripheral surface of joint P2. From this state, the screw 63 is screwed in to increase the distance L between the opposing surface 21 of the clamp body 17 and the abutment portion 35 of the movable claws 31B, bringing the movable claws 31B into contact with the outer peripheral surface of joint P2. The positioning mechanism 33B restricts the movement of the movable claws 31B, thereby absorbing any irregularities on the outer peripheral surface of joint P2 and allowing the movable claws 31B to provisionally grip joint P2. From this state, the pair of clamp bodies 17 are brought even closer together so that the movable claws 31B finally grip joint P2.

Note that this centering mechanism 30B is designed to increase distance L by moving movable claw 31B away from opposing surface 21 by tightening screw 63. However, to fine-tune the contact force of movable claw 31B against joint P2, it is also possible to move movable claw 31B closer to opposing surface 21 while movable claw 31B is in contact with the outer circumferential surface of joint P2 by loosening screw 63.

Next, a centering mechanism 30C according to yet another embodiment will be described using Figure 17. This centering mechanism 30C is provided in the second clamp unit 6 of the pipe connecting device 1A in place of the centering mechanism 30A described above.

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 abut 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 movement 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., in 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 abut 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.

The movable claw 31C has a triangular (or curved concave) notch on its surface and has multiple (two in Figure 17) abutment portions 35 that abut against the outer peripheral surface of the joint P2 at spaced positions along the outer peripheral surface. This makes it easy to accommodate multiple sizes of joint P2 and allows for stronger abutment against the outer peripheral surface of the joint P2. The number of abutment portions 35 may be three or more.

The movement mechanism 32C and positioning mechanism 33C each comprise a screw portion 73 formed on the tip of an operating rod 76 and a threaded hole 74 formed on the back side of the movable claw 31C into which the screw portion 73 threads. The operating rod 76 is supported by a bracket 71 so that it can rotate freely around an axis that follows the movement direction of the movable shaft 31C. The movement mechanism 32C moves the movable claw 31C away from the opposing surface 21 by rotating the operating rod 76 in a direction that loosens 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 peripheral 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 threaded hole 74 by stopping the rotation of the operating rod 76.

In addition, the rotation of the operating rod 76 may be performed automatically by driving a drive source (e.g., a pneumatic cylinder, a hydraulic cylinder, a motor, etc.) rather than 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 Figure 18). This improves the operability of the operating rod 72.

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 to which the linear motion shaft 77 is supported. In other words, 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 using only the movement mechanism 32C, the linear motion mechanism 34C is not necessarily required.

With the second clamp unit 6 equipped with this centering mechanism 30C, the pair of clamp bodies 17 are brought closer together so that the movable claws 31C face the outer peripheral surface of joint P2. From this state, the screw portion 73 is loosened so that the distance L between the opposing surface 21 of the clamp body 17 and the abutment portion 35 of the movable claws 31C increases, bringing the movable claws 31C into contact with the outer peripheral surface of the joint. The positioning mechanism 33C restricts the movement of the movable claws 31C, thereby absorbing any irregularities on the outer peripheral surface of joint P2 and allowing the movable claws 31C to provisionally grip joint P2. From this state, the pair of clamp bodies 17 are brought even closer together so that the movable claws 31C finally grip joint P2.

Note that this centering mechanism 30C is designed to increase distance L by rotating the operating rod 72 to loosen the screw portion 73 and move the movable claw 31 away from the opposing surface 21. However, to fine-tune the contact force of the movable claw 31C against the joint P2, the operating rod 72 can be rotated to tighten the screw portion 73 while the movable claw 31B is in contact with the outer circumferential surface of the joint P2, thereby moving the movable claw 31C closer to the opposing surface 21 and adjusting to decrease distance L.

Next, a centering mechanism 30D according to yet another embodiment will be described using Figure 19. Note that this centering mechanism 30D is provided in the second clamp unit 6 of the pipe connecting device 1A instead of the above-mentioned centering mechanism 30A.

The centering mechanism 30D can freely adjust the distance L between the opposing surfaces 21 of the clamp bodies 17 and the abutment portions 35 of the movable claws 31D abutting 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 body 6, thereby aligning the central axes O1, O2 of the pipe P1 gripped by the first clamp body 5 and the fitting P2 gripped by the second clamp body 6. The centering mechanism 30D 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 body 6, a positioning mechanism 33D that restricts movement of the movable claws 31D abutting 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 body 17.

The movement mechanism 32D is a biasing member 82 (e.g., a coil spring, fluid spring, etc.) 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 section 6 grips the joint P2, the abutment portion 35 of the movable claw 31D abuts against the biasing force of the biasing member 82, causing the biasing member 82 to contract, thereby seamlessly moving the movable claw 31D in a direction toward the opposing surface 21. Note that multiple biasing members 82 (two in Figure 19) are arranged between the movable claw 31D and the bracket 81. Specifically, a biasing member 82 is arranged on each side of the movable claw 31D in the longitudinal direction.

The positioning mechanism 33D is composed of a screw hole 83 formed in the bracket 81 and a screw 84 that threads into the screw hole 83. In other words, the positioning mechanism 33D restricts the movement of the movable claw 31D by abutting the tip of the screw 84 against the movable claw 31D.

The screw 84 may be screwed in manually or automatically by driving a drive source (e.g., 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 Figure 18). This improves the operability of the screw 84.

The linear motion mechanism 34D is composed of a linear motion shaft 85 attached to the back side of the movable claw 31D and a support hole 86 formed in the bracket 81 that supports the linear motion shaft 85. In other words, the linear motion mechanism 34D linearly moves the movable claw 31D by supporting the linear motion shaft 85 in the support hole 86.

With the second clamp unit 6 equipped with this centering mechanism 30D, by bringing the pair of clamp bodies 17 closer together and abutting the movable claws 31D against the outer peripheral surface of joint P2, the biasing member 82 shortens, adjusting and reducing the distance L between the opposing surface 21 of the clamp body 17 and the abutment portion 35 of the movable claws 31D. Furthermore, by screwing in the screw 84 of the positioning mechanism 33D and abutting the movable claws 31D to restrict their movement, irregularities on the outer peripheral surface of joint P2 are absorbed and joint P2 is temporarily held by the movable claws 31D. From this state, by bringing the pair of clamp bodies 17 even closer together, joint P2 is permanently gripped by the movable claws 31D.

Next, a centering mechanism 30E according to yet another embodiment will be described using Figure 20. This centering mechanism 30E is provided in the second clamp unit 6 of the pipe connecting device 1A in place of the centering mechanism 30A described above. Furthermore, in this centering mechanism 30E, parts with the same configuration as the centering mechanism 30D described above are designated by the same reference numerals and will not be described in detail.

The centering mechanism 30E can freely adjust the distance L between the opposing surfaces 21 of the clamp bodies 17 and the abutment portions 35 of the movable claws 31D abutting the outer periphery 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 body 6, thereby aligning the central axes O1, O2 of the pipe P1 gripped by the first clamp body 5 and the fitting P2 gripped by the second clamp body 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 body 6, a positioning mechanism 33E that restricts movement of the movable claws 31D abutting the outer periphery 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 body 17.

The positioning mechanism 33E is composed of an eccentric cam 88 that is mounted on a bracket 87 and is capable of rotating and positioning in a direction perpendicular to the direction of movement of the movable claw 31D. In other words, the positioning mechanism 33E rotates the eccentric cam 88 to position it, and restricts the movement of the movable claw 31D by abutting the eccentric cam 88 against the movable claw 31D. The eccentric cam 88 may be rotated manually or automatically by a drive source (e.g., a pneumatic cylinder, hydraulic cylinder, motor, etc.).

Next, a second clamp unit 90 according to another embodiment will be described with reference to Figure 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 arranged 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 upper clamp body 91 may be swung manually by operating an operating lever 92, or may be swung automatically by a drive source (e.g., a pneumatic cylinder, a hydraulic cylinder, a motor, etc.).

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, surrounding the outer peripheral surface of the joint P2. Multiple centering mechanisms 30D (three in the figure) are also provided, each equipped with movable claws 31D 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 surfaces 21 are 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 from the centering mechanisms 30A to 30E described above, for example.

Next, a pipe connecting device 1B according to another embodiment will be described using Figure 22. Note that in this pipe connecting device 1B, parts with substantially the same configuration as those in the above-described pipe connecting device 1A are designated by the same reference numerals and detailed description will be omitted.

This piping joining device 1B uses a socket method 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). The outer peripheral surface of the open end of pipe P1 is not reinforced with FRP.

This piping connection device 1B comprises 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 95 that is provided on the first base 2 and grips 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 grips the fitting P2 so that its central axis O2 extends parallel to the movement axis M.

The first clamp section 95 has a pair of clamp bodies 17 that can be opened and closed in the horizontal direction (i.e., width direction) perpendicular to the movement axis M. Multiple pairs of clamp bodies 17 (two pairs in Figure 1) are provided spaced apart in the direction of the movement axis M. Each of the multiple pairs of clamp bodies 17 is provided with a centering mechanism 30A.

The pipe joining method using the pipe joining device 1B is identical to the pipe joining method using the pipe joining device 1A except for the pipe centering process. The pipe centering process is performed using a centering jig 96. This 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 portion 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 centering the pipe P1 and the fitting P2. This centering jig 96 allows for proper centering of the fitting P2, whose inner periphery at the open end is tapered, and the pipe P1. Furthermore, with this piping connection device 1B, an FRP-reinforced pipe P1 can be gripped without misalignment, and an FRP-reinforced fitting P2 can be gripped without misalignment. In this embodiment, the outer peripheral surface (outer diameter) of the open end of the pipe P1 is inserted into the cylindrical first holding portion 97 to align the first holding portion 97 with the pipe P1 (see FIG. 22 ). However, this is not limited to this. For example, a convex first holding portion 97 may be inserted into the inner peripheral surface (inner diameter) of the open end of the pipe P1 to align the first holding portion 97 with the pipe P1.

The present invention is not limited to the above-described embodiment, and various modifications within the scope of the present invention are possible based on the purpose and application. In other words, the above-described embodiment of the pipe connection device 1A illustrates a centering mechanism 30A equipped with a movable claw 31A having a single abutment portion 35 that abuts against the outer peripheral surface of the fitting P2. However, this is not limited to this, and the centering mechanism 30A may also include a movable claw 31A having multiple abutment portions 35 that abut against the outer peripheral surface of the fitting P2 at spaced positions along the outer peripheral surface.

In addition, in the above-described embodiment of the pipe connecting device 1A, the centering mechanism 30A is exemplified as one in which the movable claw 31A cannot tilt about an axis along its movement direction, but this is not limited to this. For example, the centering mechanism 30A may be one in which the movable claw 31A can tilt about an axis along its movement direction.

In addition, in the above-described embodiment of the pipe connecting device 1A, the centering mechanism 30A is illustrated as including a positioning mechanism 33A having a first restricting member 41 and a second restricting member 42. However, this is not limited to this. For example, the centering mechanism 30A may include 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.

In addition, in the above-described embodiment of the pipe connecting device 1A, the second clamp unit 6 is illustrated as having four centering mechanisms 30A, but this is not limited to this, and the second clamp unit 6 may also have, for example, three or five or more centering mechanisms 30A.

In addition, while the pipe connection device 1A in the above-described embodiment illustrates a configuration in which the open ends of the pipe P1 and the fitting P2 are fused together using a socket method, this is not limited to this configuration. For example, the pipe connection 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 connection device 1A may also fusion-bond the axial end faces of the open ends of a pair of piping components P1 and P2 by butting them together. The socket connection between the open ends of the pipe P1 and the fitting P2 can be performed in accordance with, for example, Japanese Industrial Standards (JIS K6741, K6777), American Society for Testing and Materials Standard (ASTM D1785), German Industrial Standard (DIN 8062), etc.

This invention can be widely used as a technology for joining the open ends of first and second resin piping members by aligning their central axes.

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: Movement mechanism, 33A-33E: Positioning mechanism, 34A-34D: Linear motion mechanism, 35: Contact portion, 40: Pressing member, 41: First restricting member, 41a: First inclined surface, 42: Second restricting member, 42a: Second inclined surface, P1: Pipe, P2: Joint, L: Distance, M: Movement axis.

Claims (12)

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. The piping connecting device according to claim 1, wherein the biasing member is shortened to adjust the distance (L) between the clamp body and the movable gripper to be small, and the positioning mechanism restricts the movement of the movable gripper, thereby temporarily gripping the one piping member with the one clamp portion, and the pair of clamp bodies is brought even closer to each other from the temporary gripping state to finally grip the one piping member with the one clamp portion. 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. The pipe connecting device according to claim 3, wherein the linear motion mechanism includes a bush or a support hole provided in the clamp body, and a linear motion shaft guided by the bush or the support hole so as to be linearly movable. 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. 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. A piping connection device according to any one of claims 1 to 6, 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 piping connecting device according to claim 7, wherein the pipe or the joint is reinforced by spirally wrapping a tape-like fiber-reinforced plastic around an outer circumferential surface thereof with a partial overlap. 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. The pipe connecting device according to claim 1, wherein the first pipe member and the second pipe member are made of a material selected from the group consisting of polyvinyl chloride, polyethylene, polypropylene, and polyvinylidene fluoride. 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. 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 .