JP2016036850A - Workpiece holding device for welding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a workpiece holding device for welding capable of solving the problem arising when an operation mechanism for clamps, provided between multiple clamps used for a large sized workpiece, is applied.SOLUTION: A device body 26 rotatable with a workpiece placed thereon includes clamps 27, 28 on one and the other sides, for holding the workpiece from both sides. Between these clamps 27, 28, there is provided an operation mechanism 81 for clamps, for moving the clamps 27, 28 on both sides in workpiece holding directions. The operation mechanism 81 for clamps includes a clamp cylinder 82 and an intervening object 83 connected to each other and provided between the clamps 27, 28 on both sides, and the connection part is coupled to the device body 26 by a link 84. An air cylinder 93 is provided at the link 84, and the link 84 is energized resiliently in an expanding direction of the clamp cylinder by energization force set less than clamping force of the clamp cylinder 82.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a welding work holding device used as a jig for holding a work in tack welding or the like.

  For example, in a can making operation when assembling a counterweight such as a hydraulic excavator, there is a step of temporarily welding each component such as a front sheet material (front sheet) and a rear sheet material (shell sheet) as a workpiece, Conventionally, a tack welding jig capable of clamping and reversing these workpieces has been used.

  Since this conventional tack welding jig has a box structure with a thick jig body, welding is performed when the workpiece set on the jig body is flipped together with the jig body and tack welded from the back side. Since workability is reduced, it is possible to improve welding workability when performing tack welding by improving the jig body to a flat frame structure having a uniform thickness as a whole. In the conventional work clamp for fixing the work to the jig body, a large number of clamp arms are arranged along the outline of the work, and these clamp arms are individually moved by corresponding hydraulic cylinders to hold the work. Therefore, since the structure and piping are complicated and affect the welding workability, further improvement is desired.

  Here, although the technical fields are different and it cannot be said that they are technically close, one clamp cylinder is provided between the two sets of clamp arms, and the two sets of clamp arms are clamped by this clamp cylinder. There is a bar cutting device provided with a clamp operating mechanism for clamping the bar (see, for example, Patent Document 1).

JP 58-103961 A

  Although the clamp operating mechanism used in this bar cutting device can be applied to a temporary welding jig, there is a problem.

  That is, the bar cutting device operates both of the two sets of clamp arms by one clamp cylinder. However, when used for a large workpiece such as a counterweight of a construction machine, The clamp arm is greatly separated due to the large separation between the clamp arms, the clamp cylinder lengthened by the reaction force during clamping may be buckled, and the resistance and center of gravity changes in the moving part of the clamp arm Due to changes in external factors such as the above, problems such as irregular movements in which the clamp arms on both sides do not operate in a fixed order occur.

  The present invention has been made in view of such a point, and an object of the present invention is to provide a welding work holding device capable of solving the problems in the case of applying a clamp operation mechanism between a plurality of clamps used for a large work. And

  According to the first aspect of the present invention, there is provided an apparatus main body that is rotatable with a work placed thereon, clamps on one side and the other side that hold the work on the apparatus main body from both sides, and a space between these clamps. A clamping cylinder that moves the clamps on both sides in the workpiece holding direction, and the clamping actuation mechanism moves the clamps on both sides between the workpiece holding position and the workpiece opening position by expansion and contraction, and Connected to one end of this clamp cylinder and the inclusion provided between the clamps on both sides together with the clamp cylinder, and pivotally supported by the main body of the apparatus, and rotatably supports the connection between the clamp cylinder and the inclusion And a work holding device for welding provided with a link.

  The invention described in claim 2 has a function in which the clamp operating mechanism in the welding work holding device according to claim 1 has a function of moving the clamps on both sides in the work holding direction by acting the clamp cylinder in the extending direction. A welding work holding device provided with an urging means that urges at least one of a clamp cylinder, an inclusion, and a link in an extension direction of the clamp cylinder by an urging force set smaller than a clamping force of the clamp cylinder.

  According to a third aspect of the present invention, there is provided a welding work holding device using an air cylinder that elastically urges the link in the direction of extension of the clamp cylinder as the biasing means in the welding work holding device according to the second aspect. is there.

  According to a fourth aspect of the present invention, the clamp in the welding work holding device according to any one of the first to third aspects includes a plurality of clamp arms arranged in parallel to each other, and a beam shape connecting the clamp arms. It is the workpiece holding device for welding provided with the member.

  According to a fifth aspect of the present invention, in the welding work holding device according to any one of the first to fourth aspects, the front-side sheet material and the rear-side sheet material of the counterweight mounted on the work machine are temporarily used as works. A welding work holding device for positioning and holding during welding, wherein the front side sheet material is positioned and fixed on the main body of the counterweight, and the bottom surface and the top of the counterweight are fixed. A bottom surface portion and a top surface portion that are surfaces are projected on the apparatus main body, and the rear surface sheet material includes a lower portion that faces the bottom surface portion of the front surface sheet material, and an upper portion that faces the top surface portion of the front surface sheet material. Is positioned and placed on the upper side of the front side sheet material, the clamp is a clamp on one side that abuts a portion corresponding to the lower side of the counterweight of the rear side sheet material And a clamp on the other side that contacts the portion corresponding to the upper side of the counterweight of the rear side sheet material, and the clamp on the lower side of the counterweight and the clamp on the upper side of the counterweight move the rear side sheet material to the apparatus main body side. A plurality of pressing bodies to be pressed, a plurality of temporary welded portion shape confirmation plates having edge portions along the temporary welded portion of the rear side sheet material, and edges of these temporary welded portion shape confirmation plates And a plurality of pressers for pressing the edges along the tack welded portion of the rear side sheet material.

  According to the first aspect of the present invention, the clamp operating mechanism provided between the plurality of clamps includes a clamp cylinder, an inclusion connected to one end of the clamp cylinder, and a connection portion between the clamp cylinder and the inclusion. In addition, the clamp cylinder can be prevented from being lengthened by inclusions even when a clamp operating mechanism is applied between a plurality of clamps used for a large workpiece. The clamp cylinder and the inclusions can be prevented from bending due to the compressive load of the reaction received from the clamp during the extension operation of the clamp cylinder, so that the link provided at the connecting portion can prevent the clamp cylinder and the inclusion from being provided between the multiple clamps used for large workpieces. The buckling of the clamp operating mechanism can be prevented.

  According to the second aspect of the present invention, the biasing means can prevent the clamps on both sides from being irregularly operated not to operate in a fixed order due to a change in external factors, and a clamp operation sequence with good workability can be obtained. It is done.

  According to the invention described in claim 3, by using the air cylinder as the urging means, a stable urging force of the set pressure can be obtained.

  According to the invention described in claim 4, since the clamps on one side and the other side are constituted by a plurality of clamp arms and a beam-like member connecting them, the plurality of clamp arms connected by the beam-like members are synchronized. Because it moves, the workpiece can be clamped with a uniform holding force, and even if the number of clamp arms is reduced and the distance between each clamp arm is increased, the workpiece can be securely fixed, reducing the manufacturing cost of the device, and each clamp arm The welding workability can be improved by expanding the welding work space.

  According to the fifth aspect of the present invention, the apparatus main body is suitable as a tack welding jig for positioning and holding the front side sheet material and the rear side sheet material of the counterweight mounted on the work machine. Corresponding to the bottom and top surfaces of the counterweight bottom and top surfaces of the front sheet material positioned and fixed above, the portion corresponding to the counterweight lower side of the rear sheet material and the counterweight upper side Are provided on each of the one-side clamp and the other-side clamp when the parts to be pressed are fixed by a plurality of pressing bodies provided on the one-side clamp and the other-side clamp, respectively. The shape of the tack welded portion of the rear side sheet material can be confirmed by the obtained tack welded portion shape confirmation plate, and the edge along the tack welded portion of the rear side sheet material can be pressed. A plurality of presser which, a tack welding portion of the rear side sheet material can be accurately positioned, it is possible to improve the accuracy of tack welding.

It is sectional drawing which shows one Embodiment of the workpiece holding apparatus for welding which concerns on this invention. It is a perspective view from the lower side of a holding device same as the above. It is a perspective view in the state where the device main part of the holding device same as the above was rotated. It is a perspective view which shows the state which set the front side sheet material to the holding | maintenance apparatus same as the above. It is a perspective view which shows the state which set the front side sheet material and the back side sheet material to the holding | maintenance apparatus same as the above. It is a perspective view which shows the tack welding part of the counterweight which is tack-welded in a holding | maintenance apparatus same as the above, (a) is a perspective view from the front upper side, (b) is a perspective view from the back lower side. It is explanatory drawing which shows the effect | action at the time of clamping of a holding | maintenance apparatus same as the above, (a) is the unclamped state before a clamp start, (b) is the state in the middle of clamping, (c) shows the state at the time of a clamp end. It is explanatory drawing which shows the effect | action at the time of unclamping of a holding | maintenance apparatus same as the above, (a) is the clamped state before unclamping start, (b) is the state in the middle of unclamping, (c) shows the state at the time of unclamping completion | finish. . It is a side view which shows the working machine provided with the counterweight manufactured by the tack welding etc. by a holding device same as the above.

  Hereinafter, the present invention will be described in detail based on one embodiment shown in FIGS.

  As shown in FIG. 9, a hydraulic excavator 11 as a work machine is provided with a lower traveling body 12 so that a turning frame 14 of an upper turning body 13 is turnable, and a cab 15 and a front work are provided at a front portion of the turning frame 14. A device 16 and the like are mounted, and a counterweight 17 is mounted at the rear of the swivel frame 14 to maintain a weight balance. The casing of the counterweight 17 is obtained by welding a front side sheet material 17f (front sheet) and a rear side sheet material 17r (shell sheet) as workpieces to be temporarily welded.

  1 to 5 show welding work holding devices used as jigs for tack welding the front side sheet material 17f and the rear side sheet material 17r at the stage of manufacturing the counterweight 17 mounted on the hydraulic excavator 11. 20 is shown.

  As shown in FIG. 6, the front side sheet material 17 f is formed by bending a bottom surface portion 17 fb and a top surface portion 17 ft serving as a bottom surface and a top surface of the counter weight 17 with respect to a portion serving as a front surface of the counter weight 17. Yes. The peripheral edge portion of the rear sheet material 17r is temporarily welded to the peripheral edge portion of the front side sheet material 17f by a temporary welding portion 21 along the trim line indicated by a dotted line in FIG. A mounting portion of the metal fitting 22 is temporarily welded by a temporary welding portion 23 indicated by a dotted line. Prior to the tack welding, all internal members (not shown) provided in the front side sheet material 17f and the rear side sheet material 17r are connected to the front side sheet material on the welding work holding device 20. Main welding is performed in the material 17f.

  As shown in FIGS. 2 to 5, a welding work holding device 20 includes a device main body 26 that can be rotated in a state in which a front side sheet material 17f and a rear side sheet material 17r serving as workpieces are placed, and the apparatus main body. 26, main clamps 27 and 28 on one side and the other side for holding the workpiece on both sides of the counterweight from the lower side and the upper side.

  The clamp 27 on one side is in contact with a portion corresponding to the lower side of the counterweight of the rear surface side sheet material 17r, and the clamp 28 on the other side is in contact with a portion corresponding to the upper side of the counterweight of the rear surface side sheet material 17r.

  As shown in FIG. 2, the apparatus main body 26 has a plurality of auxiliary plates 26a welded to a frame 26f framed by a square pipe, and a central main table 26m and a left and right gaps between them. The left and right side plates 26s are welded to each other. As shown in FIG. 3, between the main table 26m and the left and right side plates 26s, the front side sheet material 17f and the rear side are provided from the back side. Slits 29 for tack welding the sheet material 17r are provided, respectively, and suction pads 30 for sucking and holding the front side sheet material 17f by vacuum pressure are provided at the four corners of the main table 26m.

  As shown in FIGS. 3 to 5, the apparatus main body 26 is pivotally supported on bearings 33 and 34 on one side and the other side bases 31 and 32, and one side base 31 is provided. It is rotated by the motor / decelerator 35 installed above.

  Then, the front-side sheet material 17f is set as shown in FIG. 4 to the welding work holding device 20 in which the apparatus main body 26 is rotated in the posture shown in FIG. The front side of the weight 17 is positioned and fixed by the suction pad 30 as described later. At this time, the bottom surface portion 17fb and the top surface portion 17ft which are the bottom surface and the top surface of the counterweight 17 are projected onto the apparatus main body 26.

  Further, as shown in FIG. 5, the rear side sheet material 17r is placed on the upper side of the front side sheet material 17f, the lower part 17rl facing the bottom surface part 17fb of the front side sheet material 17f, and the front side sheet material The upper surface 17ru facing the top surface portion 17ft of 17f is positioned and fixed as will be described later.

  As shown in FIGS. 3 and 4, a pair of vertical positioning plates 36 and three locking plates 37 are attached to a portion of the main table 26m corresponding to the lower side of the counterweight. As shown in FIG. 4, the direction positioning plate 36 and the locking plate 37 position and lock the bottom surface portion 17fb corresponding to the counterweight bottom surface side of the front sheet material 17f.

  As shown in FIG. 3, a pair of notch grooves 38 are provided in a portion corresponding to the counterweight bottom surface side of the main table 26m, and a pair of constraining plates 39 are projected so as to protrude from these notch grooves 38. Is attached to the frame 26f of the apparatus body 26. The U-shaped turning frame mounting support 40 is positioned and restrained by these restraining plates 39 as shown in FIG.

  As shown in FIG. 4, a plurality of mounting bosses 42 that are screwed with the restraining bolts 41 respectively inserted into the plurality of holes drilled in the restraining plates 39 are provided on the upper side surfaces of the swivel frame mounting supports 40. Yes, since each turning frame mounting support 40 and each mounting boss 42 are fixed by each restraint bolt 41, each edge of the notch 17fn formed by partially cutting the bottom plate portion 17fb of the front side sheet material 17f The swivel frame mounting support 40 is welded to each other, and a plurality of mounting bosses 42 are welded to the upper surface of each swivel frame mounting support 40.

  When the counterweight 17 is attached to the swivel frame 14 of the excavator 11, the pair of swivel frame mounting supports 40 is a pair of platforms (see FIG. The mounting bolts (not shown) are mounted on the mounting bosses 42 and inserted from below the mounting bases.

  As shown in FIGS. 3 to 5, a main clamp 27 on one side that abuts a portion corresponding to the lower side of the counterweight of the rear side sheet material 17r, and an upper side of the counterweight of the rear side sheet material 17r. The side clamps 43 and 44 that contact the left and right side portions of the rear side sheet material 17r are respectively connected to the left and right side plates 26s of the apparatus body 26 with respect to the other main clamp 28 that contacts the corresponding part. It is pivotally supported.

  The side clamps 43 and 44 are each provided with a plurality of elastic pressing elements 45 on the upper part, and on the lower part are contour correction plates 46 that abut on the left and right side surfaces of the rear side sheet material 17r to correct their contours. Are attached to each.

  The elastic pressing elements 45 and the contour correction plates 46 of these side clamps 43 and 44 are shown in FIG. 2 by hydraulic cylinders 47 and 48 respectively attached to the lower side of the apparatus main body 26 by shafts as shown in FIG. 4 is rotated from the open state shown in FIG. 4 to the state in contact with the rear side sheet material 17r shown in FIG.

  Further, as shown in FIGS. 3 to 5, the corner clamps 51 that respectively contact the lower left and right corners of the rear side sheet material 17r, and the upper left and right corners of the rear side sheet material 17r, respectively. The corner clamps 52 are pivotally supported by the respective shafts 53 on the mounting plates on the left and right side plates 26s.

  Then, each hydraulic cylinder 55 is attached to another mounting plate on the side plate 26s by each shaft 54, and the rod tips of these hydraulic cylinders 55 and the corner clamps 51, 52 are connected by each shaft 56. Each corner clamp 51, 52 is configured to be rotated by each hydraulic cylinder 55.

  Further, as shown in FIGS. 3 to 5, positioning plates 57 are respectively attached to the left and right side plates 26s so as to face the slits 29 for temporary welding from the back side.

  As shown in FIG. 4, semicircular width direction positioning pins 58 for positioning the left and right ends of the front side sheet material 17f are provided at the center of these positioning plates 57, respectively. As shown in FIG. 5, a plurality of tapered taper-shaped correction pins 59 for correcting the lower left and right side lower shape of the rear side sheet material 17r are respectively provided on the portion corresponding to the lower side of the counterweight. Yes.

  1 and 5, the rear side sheet material 17r includes a lower portion 17rl facing the bottom surface portion 17fb of the front side sheet material 17f, and the front side sheet material. A top surface portion 17ft of 17f and an upper portion 17ru facing the same are positioned and placed on the upper side of the front side sheet material 17f.

  Next, as shown in FIGS. 1 to 5, the main clamp 27 on one side that holds the portion corresponding to the lower side of the counterweight includes a plurality of clamp arms 61 arranged in parallel to each other, and A plurality of beam-like members 62 and 63 that connect the clamp arm 61, and similarly, a main clamp 28 on the other side that holds a portion corresponding to the upper side of the counterweight has a plurality of clamps arranged in parallel to each other An arm 64 and a plurality of beam members 65 and 66 connecting these clamp arms 64 are provided.

  By providing these beam-like members 62, 63, 65, 66 and connecting a plurality of clamp arms 61, 64, the work of the clamp arms 61, 64 becomes non-uniform during the clamping operation and is temporarily welded. Prevents tilting.

  As shown in FIG. 1, the clamp arms 61 and 64 are pivotally supported by bearing shafts 67 and 68 attached to the apparatus main body 26 so that the lower portions of the clamp arms 61 and 64 can be rotated relatively. The projections 61a and 64a protrude downward from these shaft support portions. Under the bearing plates 67 and 68, stoppers 71 and 72 for locking the convex portions 61a and 64a of the clamp arms 61 and 64 in a state where the clamp arms 61 and 64 are rotated in a predetermined angular opening direction. Is provided.

  As shown in FIG. 1, the rear side sheet material 17r is attached to the clamp 27 on one side and the clamp 28 on the other side by rods 73 and 74 attached to the upper ends of the clamp arms 61 and 64, respectively. A plurality of roller-like pressing bodies 75 and 76 that press toward the 26 side are provided.

  Further, as shown in FIGS. 1 and 3, along the beam-like member 63 between the upper portions of the clamp arms 61 on one side, and similarly along the beam-like member 66 between the upper portions of the clamp arms 64 on the other side. A plurality of temporary welded portion shape confirmation plates 77 and 78 having a lower edge portion along the temporary welded portion 21 (FIG. 6) of the trim line are attached, and the shape of the temporary welded portion is confirmed. A plurality of pressing elements 79 and 80 for pressing the edge portion along the tack welded portion 21 are attached at predetermined pitches along the lower edge portion of the plates 77 and 78, respectively.

  Next, as shown in FIGS. 1 and 2, the welding work holding device 20 includes a clamp arm 61 of a clamp 27 on one side that holds a portion corresponding to the lower side of the counterweight, and an upper side of the counterweight. A clamp actuating mechanism 81 is provided between each clamp arm 64 of the clamp 28 on the other side that holds a portion corresponding to the above.

  In the illustrated embodiment, these clamping actuation mechanisms 81 are provided in three rows in parallel, and the clamping actuation mechanisms 81 in each row move the clamps 27 and 28 on both sides to the workpiece holding position and the workpiece release by an expansion / contraction operation. A clamp cylinder 82 that is moved between positions, an inclusion 83 that is connected to one end of the clamp cylinder 82 and is provided between the clamps 27 and 28 on both sides together with the clamp cylinder 82, and an apparatus main body 26, each of which has a link 84 pivotally supported by 26 and rotatably supporting the connecting portion between the clamp cylinder 82 and the inclusion 83. It has a function to move the clamps 27 and 28 in the workpiece holding direction.

  Each of the clamp cylinders 82 is a hydraulic cylinder that can be extended and retracted by a hydraulic circuit as shown in FIG. 1, and the tip end of the piston rod 85 is clamped by a shaft 86 corresponding to the upper side of the counterweight. It is rotatably connected to a convex portion 64a projecting from the lower portion of the projection.

  As shown in FIG. 1, the inclusion 83 is a long tubular body having a fixed length provided with shaft connecting portions 87 and 88 at both ends. The shaft connecting portion 87 at one end is connected to the clamp cylinder by a shaft 89. It is rotatably connected to the cylinder body head end portion of 82, and the shaft connecting portion 88 at the other end is rotated by a shaft 90 to a convex portion 61a protruding from the lower portion of the clamp arm 61 corresponding to the lower side of the counterweight. It is connected freely.

  In this way, by connecting the two clamps 27 and 28 with the clamp cylinder 82 and the inclusion 83, the clamp cylinder 82 only needs to have a stroke necessary for the clamping operation. There is no need to use a cylinder. In other words, it is possible to prevent the cylinder stroke of the clamp cylinder 82 from becoming long even when the two clamps 27 and 28 are largely separated to hold a large workpiece like a counterweight material.

  One end of the link 84 is rotatably connected to a bracket 91 attached to the lower surface of the main table 26m by a shaft 92, and the other end of the link 84 rotates to a shaft 89 that connects the clamp cylinder 82 and the inclusion 83. It is connected freely.

  As described above, the link 84 is rotatably attached to the shaft 89 connecting the clamp cylinder 82 and the inclusion 83, and the link 84 is suspended from the lower surface of the apparatus main body 26. The clamp cylinder 82 and the inclusion 83 are bent by the compressive load of the reaction received from the clamps 27 and 28 during the extension operation, that is, the buckling of the clamp operating mechanism 81 is prevented.

  In addition, in the operating range other than the completion of clamping and unclamping, the upper and lower clamp arms 61 and 64 are moved in a certain order due to changes in external factors such as resistance generated in the moving parts of related parts and changes in the center of gravity. Since there is a possibility of irregular movement without operation, it is necessary to provide regularity in the movement of the clamp arms 61 and 64. As a countermeasure, the welding work holding device 20 includes an air cylinder 93 as an urging means that elastically urges the link 84 in the extension direction of the clamp cylinder by an urging force set smaller than the clamping force of the clamp cylinder 82. I have.

  2, the air cylinder 93 is provided only at the central portion of the apparatus main body 26 as shown in FIG. 2, and is attached to a bracket 94 attached to the side surface of the frame 26f as shown in FIG. Are connected to the intermediate portion of the link 84 so that the tip end portion of the piston rod 96 is rotatably connected by a shaft 97.

  Then, the air cylinder 93 is configured to dispose the inclusion 83 by applying air pressure to the piston in the cylinder body in a direction in which the piston rod 96 is always pulled in by a cylinder internal pressure or an external accumulator or a pneumatic circuit. The state where the force in the direction of projecting to the outside of the main body 26 is applied is maintained, and the clamp arm 61 on the lower side of the counterweight is biased in the clamping direction.

  In the structure of the illustrated embodiment, the air cylinder 93 is attached only to the link 84 attached to the center one of the three clamp cylinders 82, but the number of air cylinders may be increased as necessary.

  The biasing means of the welding work holding device 20 may be a coil spring, air, or any other means that elastically biases at least one of the clamp cylinder 82, the inclusion 83, and the link 84 in the direction in which the clamp cylinder extends. A spring or a gas spring may be used instead of the air cylinder 93.

  Next, the function and effect of the illustrated embodiment will be described.

(Function)
Since the distance between the force points of the opposing clamp arms 61 and 64 is long, connecting the inclusion 83 to the clamp cylinder 82 can prevent the clamp cylinder 82 from becoming too long. If pressure is applied to the extending side of the clamp cylinder 82, a weak portion, for example, the piston rod 85 of the clamp cylinder 82 may be bent, and the buckling of the clamp cylinder 82 and the inclusion 83 needs to be considered. As a countermeasure against this buckling, a link 84 is connected to the joint between the clamp cylinder 82 and the inclusion 83, and the joint is suspended from above via the link 84. As a result, the clamp cylinder 82 and the inclusions 83 are independent in strength and can withstand the individual strengths, so that the amount of deflection is reduced.

  Further, in the structure in which the joint between the clamp cylinder 82 and the inclusion 83 is only supported by the link 84, when the two main clamps 27 and 28 are moved in the opening / closing direction, the front side as a workpiece Depending on the reversal angle and holding position of the sheet material 17f and the rear surface sheet material 17r, the operation starting from the clamps 27 and 28 on the bottom surface side or the top surface side changes. An air cylinder 93 for link tension is attached to the middle part of the link 84 attached to the connection part, and the base end part of the air cylinder 93 is rotatably attached to the device main body 26 side. By pulling toward the inclusion 83 side, the two sets of clamps 27 and 28 are always opened and closed in a certain order.

  The operation will be specifically described below.

  First, the apparatus main body 26 is rotated as shown in FIG. 3, and the front sheet material 17f is placed on the main table 26m of the apparatus main body 26 as shown in FIG. Positioning is performed by the stop plate 37 and the width direction positioning pin 58, and the front side sheet material 17f is sucked by the suction pad 30 and fixed on the main table 26m.

  As shown in FIG. 4, the welding frame holding support 40 and the mounting boss 42 are fully welded to the front side sheet material 17f on the welding work holding device 20, and all the counterweight internal members are installed in the front side sheet material 17f. Main welding (not shown) is performed.

  As shown in FIG. 5, the rear sheet material 17r is fitted on the front sheet material 17f, and a plurality of shape correction pins 59 provided on the left and right positioning plates 57 are disposed on the left and right side plates 26s. The rear side sheet material 17r is positioned by the provided four corner clamps 51, 52 and the contour correcting plate 46, and the main clamps 27, 28 on both sides and the left and right side clamps 43, 44 are corrected while correcting the contour. Then, the rear side sheet material 17r is clamped and fixed so as to be pressed toward the main table 26m side of the apparatus body 26.

  At this time, when clamping the main clamps 27 and 28 as shown in FIG. 7, the clamp cylinder 82 is extended from the shortest contracted state, so that both clamp arms shown in FIG. From the state in which 61 and 64 are locked by the stoppers 71 and 72, the tension biasing force of the air cylinder 93 is released as the clamp cylinder 82 is extended as shown in FIG. Moves to the left, and the lower clamp arm 61 closes first. When the lower clamp arm 61 is completely closed, as shown in FIG. 7C, the extension force of the clamp cylinder 82 acts on the upper clamp arm 64 to close the upper clamp arm 64.

  Further, when unclamping the main clamps 27 and 28 as shown in FIG. 8, the clamp cylinder 82 is retracted from the longest extended state, so that both of the clamp cylinders 82 and 28 are operated as shown in FIG. From the state in which the clamp arms 61 and 64 are closed, the upper clamp arm 64 opens as shown in FIG. 8B, and the upper clamp arm 64 is fully opened until it is locked by the stopper 72. 8 (c), the inclusion 83 is moved to the right while the air cylinder 93 is forcibly stretched against the tension biasing force of the air cylinder 93 by the force in the contraction direction of the clamp cylinder 82. The lower clamp arm 61 is moved until it is locked by the stopper 71.

  Using the difference in operating time between the clamp 27 on one side and the clamp 28 on the other side as shown in FIG. 8 (b), the workpiece is transferred to the lifting bracket 22 (see FIG. 6) of the front sheet material 17f. Work such as hooking a hook of a hanging tool (not shown) is efficiently performed.

  In this way, the clamp arms 61 and 64 are placed in a certain order due to changes in external factors such as the position of the device body 26, the center of gravity of the parts, and the resistance of the moving part due to the tensile biasing force of the air cylinder 93. Therefore, the lower clamp arm 61 is clamped first, and the upper clamp arm 64 is unclamped first.

  FIG. 5 shows the apparatus main body 26 in a horizontal state, but at the time of tack welding work, the apparatus main body 26 is rotated to an angle suitable for the operation or inverted to make it easier for the operator. To be able to work in a proper posture.

(effect)
A conventional counterweight temporary welding jig has a counterweight lower clamp cylinder and an upper clamp cylinder separately to operate the two main clamps on the lower and upper counterweight sides. However, the welding work holding device 20 of the present invention has a structure in which the clamp weights on both the lower side and the upper side of the counterweight are operated by a single clamp cylinder 82, whereby the total number of clamp cylinders 82 is reduced. Can be reduced. The reduction in the number of clamp cylinders not only reduces the cost of the apparatus, but also provides an effect that it is easy to secure a work space during welding work.

  The main clamp 27 or 28 is composed of a plurality of clamp arms 61 or 64 and beam-like members 62, 63 or 65, 66 connecting them, and the clamps 27, 28 are operated using a plurality of clamp cylinders 82. Even so, the clamp arms 61 or 64 operate synchronously at the same speed, so that the front side sheet material 17f and the rear side sheet material 17r can be clamped with an equal holding force.

  Since the plurality of clamp arms 61 or 64 connected by the beam-like members 62, 63 or 65, 66 move synchronously in this way, the number of clamp arms is reduced to reduce the number of clamp arms 61, 61 or between each clamp arm. Even if the space between the 64 and 64 is enlarged, the front side sheet material 17f and the rear side sheet material 17r can be securely fixed, and the manufacturing cost of the apparatus can be reduced, and between each clamp arm 61, 61 or between each clamp arm 64, The welding workability can be improved by expanding the welding work space between 64.

  The clamp weight 82 and the inclusion 83 are connected between the two clamp arms 61 and 64, and the connecting portion between the clamp cylinder 82 and the inclusion 83 is supported by the link 84, so that the counter weight 17 can be obtained. Even when the distance between the clamps 27 and 28 is long in order to hold a large workpiece, the size of the clamp cylinder 82 can be minimized, that is, the inclusion 83 can increase the length of the clamp cylinder 82. It is possible to prevent the clamp cylinder 82 and the inclusion 83 from being bent by the compressive load of the reaction received from the clamps 27 and 28 during the extension operation of the clamp cylinder 82 by the link 84 provided at the connection portion thereof. It is possible to prevent buckling of the clamp operating mechanism 81 provided between the two sets of clamps 27 and 28 used for the workpiece.

  Further, by attaching an air cylinder 93 to the link 84 and always pulling the link 84 to the inclusion 83 side by the air cylinder 93, the clamp operation always starts from the clamp 27 corresponding to the lower side of the counterweight, and the counterweight The main clamps 27 and 28 are sequenced in a certain order that the unclamping operation starts from the clamp 28 corresponding to the upper side, and it is possible to reliably execute a clamping procedure that is favorable for work, that is, good workability. , Work safety can be achieved.

  In the urging structure using the air cylinder 93, the position of the center of gravity of the clamp arms 61 and 64 is separated from the fulcrum shaft position of the clamp arms 61 and 64, as in the case of being used as a counterweight temporary welding jig. This is effective when the external factors are likely to change, such as when the clamp arms 61 and 64 need to be opened largely with respect to the apparatus main body 26.

  That is, the air cylinders 93 as the urging means can prevent the clamps 27 and 28 on both sides from operating irregularly so as not to open and close in a certain order due to changes in external factors, as shown in FIGS. Thus, a clamp operation sequence and an unclamp operation sequence with good workability can be obtained. In particular, by using the air cylinder 93, a stable set pressure urging force can be obtained.

  Since the clamp cylinder 82 and the air cylinder 93 are combined in this way, the clamp arm 61 corresponding to the lower side of the counterweight and the clamp arm 64 corresponding to the upper side of the counterweight need not be operated by the clamp cylinder 82. Since a reliable sequence operation can be obtained, the number of clamp cylinders can be reduced, and effects such as a reduction in device manufacturing costs and a risk rate due to failure of hydraulic related parts can be obtained.

  Furthermore, it corresponds to the bottom surface portion 17fb and top surface portion 17ft of the counterweight bottom surface and top surface of the front sheet material 17f positioned and fixed on the apparatus body 26, and the counterweight lower portion side of the rear surface sheet material 17r. And the portion corresponding to the upper portion of the counterweight are fixed by being pressed by a plurality of pressing bodies 75 and 76 provided on the clamp 27 on one side and the clamp 28 on the other side, respectively. The shape of the temporary welded portion 21, that is, the trim line shape can be confirmed by the temporary welded portion shape confirmation plates 77 and 78 provided on the clamp 27 on one side and the clamp 28 on the other side, and the rear side sheet material The plurality of pressers 79 and 80 that press the edge portions along the 17r tack welded portion 21 can accurately position the tack welded portion 21 and improve the accuracy of the tack weld.

  As described above, the work welding apparatus 20 for welding is tack welding that positions and holds the front side sheet material 17f and the rear side sheet material 17r of the counterweight 17 mounted on the excavator 11 when tack welding is performed. Suitable as a jig for use.

  The welding work holding device 20 according to the present invention is not limited to use as a counterweight temporary welding jig, but is used as a welding jig other than the counterweight 17, such as a large tank. It may be.

  The present invention has industrial applicability to businesses that manufacture the counterweight 17 and the like using the welding work holding device 20, or businesses that manufacture and sell the welding work holding device 20.

11 Hydraulic excavator as work machine
17 Counter weight
17f Front side sheet material as workpiece
17fb bottom
17ft top surface
17r Rear sheet material as workpiece
17rl bottom
17ru top
20 Welding work holding device
21 Temporary welds
26 Main unit
27 One side clamp
28 Clamp on the other side
61, 64 Clamp arm
62, 63, 65, 66 Beam-shaped member
75, 76 Pressing body
77, 78 Tack weld weld shape confirmation plate
79, 80 Presser
81 Clamping mechanism
82 Clamp cylinder
83 Inclusions
84 links
93 Air cylinder as biasing means

Claims (5)

A device body that can be rotated with a workpiece placed thereon,
A clamp on one side and the other side that holds the workpiece on this device body from both sides;
A clamp operating mechanism that is provided between these clamps and moves the clamps on both sides in the workpiece holding direction;
This clamping mechanism is
A clamp cylinder that moves the clamps on both sides between the workpiece holding position and the workpiece release position by telescopic operation;
Inclusions connected to one end of the clamp cylinder and provided between the clamps on both sides together with the clamp cylinder;
What is claimed is: 1. A welding work holding device comprising: a link pivotally supported by an apparatus main body and rotatably supporting a connection portion between a clamp cylinder and an inclusion. The clamp operating mechanism has a function to move the clamps on both sides in the workpiece holding direction by acting the clamp cylinder in the extending direction,
2. An urging means for urging at least one of the clamp cylinder, the inclusion, and the link in an extension direction of the clamp cylinder by an urging force set smaller than a clamping force of the clamp cylinder is provided. The workpiece holding apparatus for welding as described. The welding work holding device according to claim 2, wherein an air cylinder that elastically urges the link in a direction in which the clamp cylinder extends is used as the urging means. The clamp
A plurality of clamp arms arranged parallel to each other;
The welding work holding device according to any one of claims 1 to 3, further comprising: a beam-like member that connects these clamp arms. A welding work holding device for positioning and holding a front side sheet material and a rear side sheet material of a counterweight mounted on a work machine when performing temporary welding as a work,
The front side sheet material is positioned and fixed on the main body of the counterweight, and the bottom surface and the top surface of the counterweight protrude from the main body.
The rear side sheet material is positioned on the upper side of the front side sheet material by positioning a lower part facing the bottom surface part of the front side sheet material and an upper part facing the top surface part of the front side sheet material,
The clamp is
A clamp on one side that comes into contact with a portion corresponding to the lower side of the counterweight of the rear side sheet material;
A clamp on the other side that comes into contact with a portion corresponding to the counterweight upper side of the rear side sheet material,
The clamp on the lower side of the counterweight and the clamp on the upper side of the counterweight are
A plurality of pressing bodies for pressing the rear side sheet material to the apparatus main body side;
A plurality of tack welded portion shape confirmation plates having edge portions along the tack welded portion of the rear side sheet material;
A plurality of pressing elements that are attached along the edges of the temporary welded portion shape confirmation plates and press the edges along the temporary welded portion of the rear sheet material, respectively. Item 5. The work holding device for welding according to any one of Items 1 to 4.

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