Clamping device

Abstract

To provide a clamp device which can easily keep constant a gap between end faces of a pair of pipe materials to be sandwiched.SOLUTION: A clamp device sandwiches outer peripheral surfaces of a pair of pipe materials 2 whose end faces to be welded face each other. The clamp device includes a plurality of sandwiching parts, and projection pieces 24. The sandwiching parts sandwich the outer peripheral surfaces of the pair of pipe materials 2. The projection pieces 24 are provided on at least one sandwiching part. The projection pieces 24 are inserted between the end faces of the pair of pipe materials 2.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a clamping device for clamping pipe materials.

Background Art

[0002] When welding the end faces of metal pipe materials to each other, the end faces are made to face each other, and in that state, temporary welding may be performed at a plurality of locations on both end faces. In this case, after temporarily welding the end faces of the pipe materials, the circumferential regions of both end faces are subjected to main welding.

[0003] In such welding work, when temporarily welding the pipe materials, the outer peripheral surfaces of both pipes are clamped by a clamping device with the end faces of the pipe materials facing each other. At this time, the pair of pipe materials are stabilized in a state where the end faces face each other by being clamped by the clamping device at the outer peripheral surfaces. A plurality of locations in the circumferential region of the end faces of the pair of pipe materials are temporarily welded by an operator in this posture.

[0004] Various clamping devices for such applications have been conventionally proposed (see, for example, Patent Documents 1 and 2).

[0005] The clamping device described in Patent Document 1 includes a main arm portion having a substantially J-shaped front view, and an auxiliary arm portion held in a linearly adjustable manner at the straight portion of the main arm portion. An operation rod is screwed into the auxiliary arm portion in a penetrating state. The tip of the operation rod faces the curved tip of the main arm portion. Pad members are attached to the tip portions of the main arm portion and the operation rod. A flat surface that abuts against the outer peripheral surface of the pipe material is formed on each pad member. Further, a gripping portion for rotating the operation rod is provided on the base end side of the operation rod.

[0006] When clamping pipe material with this clamping device, the locking position of the auxiliary arm relative to the main arm is appropriately adjusted, and a pair of pipe material is positioned between the pad member on the main arm side and the pad member on the operating rod side. In this state, the operator grasps the gripping part and rotates the operating rod in a predetermined direction, thereby displacing the operating rod toward the tip of the main arm. As a result, the pad member on the main arm side and the pad member on the operating rod side are pressed against the outer surfaces of the pair of pipe material on their respective flat surfaces. Consequently, the pair of pipe material is clamped by the pair of pad members with their end faces facing each other.

[0007] The clamping device described in Patent Document 2 comprises a fixed clamping portion and a movable clamping portion that moves toward and away from the fixed clamping portion, with a pair of pad members swingably attached to each of the fixed and movable clamping portions. Each pad member has a flat surface that contacts the outer surface of the pipe material. When the pair of pad members attached to each clamping portion are pressed against the outer surface of the pipe material, the inclination angle of each flat surface is automatically adjusted to follow the outer surface of the pipe material. As a result, the pair of pipe materials are stably clamped by the pair of V-shaped inclined flat surfaces of each clamping portion. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Patent No. 5311093 [Patent Document 2] European Patent No. 0300473 [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] The clamping devices described in Patent Documents 1 and 2 both have a structure in which the flat surface of the pad member contacts the outer circumferential surface of a pair of pipe materials. Therefore, in order to properly adjust the gap (root gap) between the end faces of a pair of pipe materials, complicated adjustment work is required at the work site, and skilled workers are required to properly adjust the gap between the end faces of a pair of pipe materials in a short time. Furthermore, the gap between the end faces of a pair of pipe materials (root gap) can easily cause welding defects during the actual welding process if it is too wide or too narrow.

[0010] Therefore, the present invention aims to provide a clamping device that can easily maintain a constant gap between the end faces of a pair of pipe materials to be clamped. [Means for solving the problem]

[0011] A clamping device according to one embodiment of the present invention is a clamping device for clamping the outer circumferential surfaces of a pair of pipe materials with opposing end faces to be welded, and is characterized by comprising: a plurality of clamping portions for clamping the outer circumferential surfaces of the pair of pipe materials; and a projection provided on at least one of the clamping portions and inserted between the end faces of the pair of pipe materials.

[0012] In the above configuration, when clamping the outer surfaces of a pair of pipe materials, the projections of the clamping parts are inserted between the end faces of the pair of pipe materials, and the projections are brought into contact with the end faces of each pipe material. In this state, when the outer surfaces of the pair of pipe materials are clamped by multiple clamping parts, the gap between the end faces of the two pipe materials is maintained at a constant interval by the projections. When the pair of pipe materials are clamped by the clamping device in this way, it becomes possible to properly perform tack welding between the end faces of the pipe materials.

[0013] The clamping portion has a flat surface that contacts the outer circumferential surfaces of the pair of pipe materials, and the projection may be provided protruding from the flat surface.

[0014] In this case, by bringing the flat surface of the clamping part into contact with the outer surfaces of the pair of pipe materials, it becomes possible to stably clamp the pipe materials. Furthermore, since the projection is provided on the flat surface that contacts the outer surfaces of the pipe materials, it becomes possible to stably position the ends of each pipe material by using the flat surface and the projection.

[0015] The clamping portion comprises a support member and a pair of pad members that are pivotably supported by the support member and each having a flat surface, wherein the pair of pad members may be configured such that when subjected to a pressing load, each of their flat surfaces contacts the outer circumferential surface of the pair of pipe materials.

[0016] In this case, when a pressing load is applied to the support member, the flat surface of each pad member comes into contact with the outer surface of the pair of pipe members. At this time, each pad member receives a reaction force from the pipe members and swings to the correct position. As a result, the pair of pad members supported by the support member have their flat surfaces inclined in a V-shape, and in that position they stably grip the outer surface of the pair of pipe members.

[0017] The clamping portion consists of a fixed clamping portion and a movable clamping portion that moves toward and away from the fixed clamping portion, and the projection may be provided only on the pad member of the fixed clamping portion.

[0018] In this case, when clamping a pair of pipe materials, first, the outer peripheral surfaces of both pipe materials are brought into contact with the flat surface of the pad member of the clamping portion on the fixed side. At this time, by adjusting the posture and the interval between both pipe materials, the end surfaces of each pipe material come into contact with the protruding pieces on the flat surface. After this, the clamping portion on the movable side is brought close to the clamping portion on the fixed side, and the flat surface of the pad member of the clamping portion on the movable side is brought into contact with the outer peripheral surfaces of both pipe materials. As a result, in the pair of pipe materials, the gap between the end surfaces is adjusted to be constant by the protruding pieces, and in that state, they are clamped by the clamping device. In this configuration, since no protruding piece is provided on the pad member of the clamping piece on the movable side, when arranging the pair of pipe materials between the pad members of both clamping portions, it is not necessary to excessively separate the clamping portion on the movable side from the clamping portion on the fixed side. Therefore, when adopting this configuration, it becomes possible to more easily perform the clamping operation on the pair of pipe materials.

Effect of the Invention

[0019] In the clamping device according to one aspect of the present invention, since a protruding piece inserted between the end surfaces of a pair of pipe materials is provided on the clamping portion, by bringing the protruding piece into contact with the end surfaces of the pair of pipe materials to clamp the pipe materials, the gap between the end surfaces of the pair of pipe materials to be clamped can be easily kept constant.

Brief Description of the Drawings

[0020] [Figure 1] FIG. 1 is a front view of the clamping device of the embodiment. [Figure 2] FIG. 2 is a side view of the clamping device of the embodiment clamping a pair of pipe materials. [Figure 3] FIG. 3 is a front view of the clamping device of the embodiment clamping a pair of pipe materials. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 3. [Figure 5] FIG. 5 is a side view showing a state of butt-welding a pair of pipe materials.

Mode for Carrying Out the Invention

[0021] Hereinafter, an embodiment of the present invention will be described based on the drawings. FIG. 1 is a front view of the clamp device 1 of the present embodiment. FIGS. 2 and 3 are side views and front views of the clamp device 1 sandwiching a pair of pipe materials 2. Note that FIG. 3 is a front view of one of the pair of pipe materials 2 with the end faces 2e facing each other as viewed from the end face 2e side. The clamp device 1 is a device that sandwiches the outer peripheral surfaces 2p of a pair of pipe materials 2 with the end faces 2e to be welded facing each other. When welding the end faces 2e of the pair of pipe materials 2, the clamp device 1 can facilitate the temporary welding operation of the end faces 2e of the pipe materials 2 by an operator by keeping the facing posture of the pair of pipe materials 2 constant. In this specification, the "pipe material" is not limited to a straight pipe, but also includes a substantially L-shaped elbow joint, a substantially T-shaped cheese joint, and the like.

[0022] The clamp device 1 includes a fixed-side clamping portion 10A (fixed-side clamping portion) and a movable-side clamping portion 10B (movable-side clamping portion) that approaches and separates from the fixed-side clamping portion 10A.

[0023] The fixed-side clamping portion 10A includes an L-shaped block 11 that is substantially L-shaped in a front view, and a locking block 12 that is held on the L-shaped block 11 so as to be position-adjustable. The L-shaped block 11 includes a base arm 11a that extends linearly in one direction, and a support arm 11b that extends by bending substantially at a right angle from one end portion in the longitudinal direction of the base arm 11a.

[0024] The base arm 11a of the L-shaped block 11 holds one end of the locking block 12. The locking block 12 is adjustable in position along the extension direction of the base arm 11a. A pad support block 13 (support member) is fixed to the side of the support arm 11b facing the locking block 12. A pair of pad members 14 are pivotably supported on the pad support block 13, spaced apart in the extension direction of the support arm 11b. Each pad member 14 is pivotably supported on a pivot 15 that extends in a direction perpendicular to the extension directions of the base arm 11a and the support arm 11b (along the axial direction of the pipe material 2 being gripped). The pad members 14 will be described in detail later.

[0025] The locking block 12 is a block that extends linearly in one direction, and one end of it is held in a position-adjustable manner on the base arm 11a of the L-shaped block 11. An engagement hole 16 is formed on one end of the locking block 12 through which the base arm 11a passes. The outer surface of the base arm 11a has irregularities (not shown). When a load is applied to the other end of the locking block 12 in a direction perpendicular to the extension direction of the locking block 12, the engagement hole 16 engages with the irregularities on the outer surface of the base arm 11a, thereby fixing the locking block 12 in position on the base arm 11a.

[0026] A threaded hole 17 is formed at the other end of the locking block 12. The threaded hole 17 is formed approximately parallel to the base arm 11a of the L-shaped block and penetrates the locking block 12. An operating rod 18, which has a male thread on its outer surface, is screwed into the threaded hole 17. The operating rod 18 constitutes the main part of the movable clamping portion 10B.

[0027] The operating rod 18 has a pad support block 19 (support member) fixed to one end in the axial direction (the side facing the pad member 14 on the L-shaped block 11 side). A pair of pad members 20 are pivotably supported on the pad support block 19, spaced apart in the extending direction of the locking block 12. Each pad member 20 is pivotably supported on a pivot 21 that extends in a direction perpendicular to the extending directions of the base arm 11a and support arm 11b of the L-shaped block 11 (along the axial direction of the pipe material 2 to be gripped).

[0028] The pad support block 19 and the pair of pad members 20 move closer to and further away from the pad support block 13 and the pair of pad members 14 on the opposing L-shaped block 11 side as the operating rod 18 is rotated. When the operating rod 18 is rotated in one direction, the pad support block 19 on the operating rod 18 side moves closer to the pad support block 13 on the L-shaped block 11 side. When the operating rod 18 is rotated in the other direction, the pad support block 19 on the operating rod 18 side moves further away from the pad support block 13 on the L-shaped block 11 side.

[0029] A through hole 22 is formed at the other axial end of the operating rod 18, extending in a direction intersecting the axial direction of the operating rod 18. A gripping rod 23 is slidably inserted through the through hole 22. The gripping rod 23 is the part that the operator grips in order to rotate the operating rod 18 when clamping the pipe material 2 with the clamping device 1. In this embodiment, the fixed clamping portion 10A (fixed clamping portion) is composed of an L-shaped block 11, a locking block 12, a pad support block 13, a pad member 14, etc. The movable clamping portion 10B (movable clamping portion) is composed of an operating rod 18, a gripping rod 23, a pad support block 19, a pad member 20, etc.

[0030] As shown in Figure 3, each pad member 14 on the L-shaped block 11 (fixed clamping portion 10A) side comprises a pair of triangular side walls 14s in side view and a substantially rectangular clamping wall 14c connected to the pair of side walls 14s. The clamping wall 14c is connected to one side of the pair of side walls 14s. The pair of side walls 14s are pivotably supported by a pivot 15 on the pad support block 13 at the diagonal portions of the sides where the clamping wall 14c connects. The outer surface of the clamping wall 14c is a flat surface 14cf that abuts against the outer circumferential surface 2p of the pipe material 2. Hereinafter, with respect to the flat surface 14cf, the direction in which the axis of the pivot 15 extends will be simply referred to as the "axial direction".

[0031] Figure 4 is a cross-sectional view along the line IV-IV in Figure 3. Each pad member 14 has a rectangular plate-shaped projection 24 protruding from its flat surface 14cf. The projection 24 is made of a plate material of approximately constant thickness and extends perpendicularly to the flat surface 14cf and the pivot 15. As shown in Figures 2 and 4, the projection 24 is positioned approximately in the center of the axial direction of the flat surface 14cf. Each projection 24 is inserted between the end faces 2e of a pair of pipe members 2 when the pair of pipe members 2 are clamped by the pad member 14 of the fixed clamping part 10A and the pad member 20 of the movable clamping part 10B with their end faces 2e facing each other. At this time, both sides of each projection 24 facing opposite directions are brought into contact with the end faces 2e of each pipe member 2. As a result, the gap d between the end faces 2e of the pair of pipe members 2 becomes a gap equal to the thickness of the projection 24.

[0032] Furthermore, as shown in Figure 3, each pad member 20 on the operating rod 18 (movable clamping portion 10B) side, like the pad member 14 on the L-shaped block 11 side, comprises a pair of triangular side walls 20s in side view and a substantially rectangular clamping wall 20c connected to the pair of side walls 20s. The pair of side walls 20s are pivotably supported by the pad support block 19 by a pivot 21. The outer surface of the clamping wall 20c is a flat surface 20cf that abuts against the outer circumferential surface 2p of the pipe material 2. However, the pad member 20 on the operating rod 18 side does not have a projection 24 on the flat surface 20cf.

[0033] Next, we will explain a specific example of welding a pair of pipe materials 2. <Temporary welding of pipe materials> First, the end faces 2e of a pair of pipe materials 2 are placed facing each other, and multiple points around the periphery of the end faces 2e are tack-welded. When tack-welding, the clamping device 1 described above is used to maintain a constant gap d between the end faces 2e of the pipe materials 2.

[0034] In advance, the operating rod 18 of the clamping device 1 is rotated in a predetermined direction to separate the pad support block 13 of the movable clamping portion 10B from the pad support block 19 on the fixed clamping portion 10A side by a predetermined distance. This creates a gap between the pad member 14 on the fixed clamping portion 10A side and the pad member 20 on the movable clamping portion 10B side, allowing a pair of pipe members 2 to be placed.

[0035] In this state, the clamping device 1 is moved to a position where the pair of pipe members 2 are positioned facing each other, and the pad member 14 on the fixed clamping side 10A side is brought into contact with the outer circumferential surfaces 2p of the pair of pipe members 2 from below. At this time, the outer circumferential surfaces 2p of both pipe members 2 come into contact with each flat surface 14cf of the pair of pad members 14 on the fixed clamping side 10A side. In this state, the relative position and angle of the pair of pipe members 2 are adjusted so that the end face 2e of each pipe member 2 comes into contact with the side surface of each projection 24 of the pair of pad members 14. In this case, since the projection 24 is a plate of a constant width, the gap d between the end faces 2e of the pair of pipe members 2 is approximately constant in the circumferential direction. Furthermore, the tilt position of the pair of pad members 14 is automatically adjusted around the pivot 15 as each flat surface 14cf abuts against the outer circumferential surface 2p of both pipe members 2.

[0036] Subsequently, the operator rotates the operating rod 18 of the clamping device 1 in a predetermined direction, thereby moving the pad support block 19 of the movable clamping portion 10B toward the pad support block 13 of the fixed clamping portion 10A. As a result, the pair of pad members 20 on the movable clamping portion 10B side are pressed against the outer circumferential surface 2p of the pipe material 2. At this time, each pad member 20 contacts the outer circumferential surface 2p of the pipe material 2 with its flat surface 20cf, and the inclination position of each pad member 20 is automatically adjusted around the pivot 21. As a result, the pair of pipe members 2 are clamped by the clamping device 1 while maintaining a constant gap d between their end faces 2e. At this time, the pad members 14 and 20 of the fixed clamping portion 10A and the movable clamping portion 10B have their respective pairs of flat surfaces 14cf and 20cf inclined in a roughly V-shape, pressing down on the outer surfaces of both pipe members 2 in a manner that encloses them.

[0037] As described above, the pair of pipe materials 2, whose outer surfaces 2p are clamped by the clamping device 1, are welded at multiple points on the outer circumference of the end faces 2e of both pipe materials 2 by a welding device (not shown). In Figures 2 and 3, the symbol w1 represents the tack weld (the part to which welding material is attached) on the end face 2e of the pipe material 2.

[0038] <Main welding of pipe materials> Figure 5 is a side view showing the process of performing final welding on a pair of temporarily fixed pipe materials 2. In this welding process, welding is performed on the remaining portion of the gap d between the end faces 2e of a pair of pipe materials 2, whose relative positions have been fixed by tack welding. This completely seals the gap d between the end faces 2e of the pair of pipe materials 2. In Figure 5, reference numeral 40 denotes the welding rod used during the main welding process, and reference numeral w2 denotes the main weld portion (the part to which the welding material is attached) of the end face 2e of the pipe material 2.

[0039] As described above, the clamping device 1 of this embodiment is provided with a projection 24 inserted between the end faces 2e of a pair of pipe materials 2 on at least one clamping portion (fixed clamping portion 10A). Therefore, by bringing the projection 24 into contact with the end faces 2e of the pair of pipe materials 2 and clamping the pipe materials 2 with the fixed clamping portion 10A and the movable clamping portion 10B, the gap d between the end faces 2e of the pair of pipe materials 2 to be clamped can be easily kept constant. Therefore, when the clamping device 1 of this embodiment is used, tack welding can be easily and appropriately performed on the end faces 2 of a pair of pipe materials 2 without requiring skilled workers. In this embodiment, the projection 24 is provided on the fixed clamping portion 10A side, but the projection 24 may also be provided on the movable clamping portion 10B side. Furthermore, the projection 24 may be provided on both the fixed clamping portion 10A side and the movable clamping portion 10B side.

[0040] Furthermore, in this embodiment, the clamping device 1 has a flat surface 14cf on the clamping portion (fixed clamping portion 10A) that contacts the outer circumferential surface 2p of the pipe material 2, and a projection 24 is provided protruding from the flat surface 14cf. Therefore, by bringing the flat surface 14cf of the clamping portion (fixed clamping portion 10A) into contact with the outer circumferential surface 2p of the pair of pipe materials 2, the pipe materials 2 can be stably clamped. In addition, because the projection 24 protrudes from the flat surface 14cf, the ends of each pipe material 2 can be stably positioned by the flat surface 14cf and the projection 24. Therefore, when this configuration is adopted, the gap d between the end faces 2e of the pair of pipe materials 2 to be clamped can be easily and accurately adjusted.

[0041] Furthermore, the clamping device 1 of this embodiment comprises a fixed clamping portion 10A and a movable clamping portion 10B, each consisting of a pad support block 13, 19 (support member) and a pair of pad members 14, 20 that are pivotably supported by the pad support blocks 13, 19 and have flat surfaces 14cf, 20cf. When the fixed clamping portion 10A and the movable clamping portion 10B are subjected to a pressing load by the rotational operation of the operating rod 18, the flat surfaces 14cf, 20cf of each pad member 14, 20 come into contact with the outer circumferential surface 2p of the pair of pipe members 2. At this time, each pad member 14, 20 receives a reaction force from the pipe members 2 and is pivoted and adjusted to the appropriate position. Therefore, when this configuration is adopted, the pair of flat surfaces 14cf and 20cf of each pad member 14 and 20 are inclined in a V-shape, and in that position, the outer circumferential surfaces 2p of the pair of pipe members 2 can be stably clamped. As a result, the gap d between the end faces 2e of the pair of pipe members 2 can be kept constant, and tack welding work on the end faces 2e of the pipe members 2 can be performed more easily.

[0042] Furthermore, in this embodiment, the clamping device 1 has a projection 24 inserted into the end face of the pipe material 2, provided only on the pad member 14 of the fixed clamping portion 10A, and not on the pad member 20 of the movable clamping portion 10B. Therefore, when clamping the outer circumferential surfaces 2p of a pair of pipe materials 2 by the fixed clamping portion 10A and the movable clamping portion 10B, it is not necessary to excessively separate the movable clamping portion 10B from the fixed clamping portion 10A. Therefore, when the clamping device 1 of this embodiment is used, the clamping operation of the clamping device 1 on a pair of pipe materials 2 can be easily performed even in environments where it is difficult to secure sufficient working space around the pipe material 2.

[0043] It should be noted that the present invention is not limited to the embodiments described above, and various design modifications are possible without departing from the spirit of the invention. For example, in the above embodiment, a pair of pad members 14 and 20 are pivotably supported on the fixed clamping portion 10A and the movable clamping portion 10B, respectively, but the pad members 14 and 20 can also be fixed to the pad support block 13 in a way that prevents them from pivoting. Furthermore, the pad members 14 and 20 of the fixed clamping portion 10A and the movable clamping portion 10B do not necessarily need to be provided in pairs; one pad member may suffice. Furthermore, the shapes of the fixed clamping portion 10A and the movable clamping portion 10B are not limited to those of the above embodiment. Various shapes can be adopted as long as they can clamp the outer circumferential surfaces 2p of the pair of pipe materials 2. Furthermore, in the above embodiment, the projection 24 is provided only on the pad member 14 on the fixed clamping portion 10A side, but the projection 24 may also be provided on the pad member 20 on the movable clamping portion 10B side. Alternatively, the projection 24 may be provided only on the pad member 20 on the movable clamping portion 10B side. [Explanation of symbols]

[0044] 1… Clamping device 2…Pipe material 2e...End face 10A... Fixed clamping part (fixed clamping part) 10B...Movable clamping part (Movable clamping part) 13, 19… Pad support block (support member) 14,20…Pad component 14cf,20cf…flat surface 24...projection piece

Claims

1. A clamping device for gripping the outer surfaces of a pair of pipe materials with their end faces to be welded facing each other, Multiple clamping portions that clamp the outer circumferential surfaces of a pair of pipe materials, It comprises a projection provided on at least one of the clamping portions and inserted between the end faces of a pair of pipe materials, The clamping portion is, The clamping part on the fixed side, It consists of a movable clamping portion that moves closer to and further away from the fixed clamping portion, A clamping device characterized in that the aforementioned projection is provided only on the clamping portion on the fixed side.

2. The clamping portion has a flat surface that contacts the outer circumferential surfaces of the pair of pipe materials, The clamping device according to claim 1, characterized in that the projection is provided protruding from the flat surface.

3. The clamping portion is, Support member and A pair of pad members, each having the flat surface, are pivotably supported by the support member, Equipped with, The pair of pad members, upon receiving a pressing load, have their respective flat surfaces on the outer circumference of the pair of pipe members. The clamping device according to claim 2, characterized in that it contacts a surface.

4. A clamping device for gripping the outer surfaces of a pair of pipe materials with their end faces to be welded facing each other, Multiple clamping portions that clamp the outer circumferential surfaces of a pair of pipe materials, It comprises a projection provided on at least one of the clamping portions and inserted between the end faces of a pair of pipe materials, The clamping portion has a flat surface that contacts the outer circumferential surfaces of the pair of pipe materials, The aforementioned projection is provided protruding from the flat surface, The clamping portion is, Support member and A pair of pad members, each having the flat surface, are pivotably supported by the support member, Equipped with, A clamping device characterized in that a pair of pad members are subjected to a pressing load, and each of their flat surfaces contacts the outer circumferential surface of the pair of pipe materials.

5. The clamping portion is, The clamping part on the fixed side, It consists of a movable clamping portion that moves closer to and further away from the fixed clamping portion, The clamping device according to claim 4, characterized in that the projection is provided only on the pad member of the fixed clamping portion.

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