JPH0133276B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to vertical workpieces and horizontal workpieces, for example, by arranging bar-shaped steel materials in a lattice pattern such as reinforcing bars embedded in concrete trench covers or chicken cages. The present invention relates to a device that automates spot welding for welding intersections of workpieces.

[Prior Art] Conventionally, when performing this type of welding, a bar-shaped steel workpiece cut to a predetermined size is inserted into a support groove provided on the inner peripheral surface of a jig and held in a lattice shape, and the welding machine is operated. The jig placed on the table is manually moved while welding at a predetermined location.

[Problems to be solved by the present invention] Therefore, it takes a lot of effort to move the jig together with the workpiece, and it is also necessary to set the moving position of the jig so that the intersecting part of the workpiece matches the electrode position. However, it takes time to make adjustments, and automation is desired.

[Means for Solving the Problems] The present invention automates such welding work, and includes a swing link and a swing link that can rotate horizontally on a pivot on the swing link. A robot is provided, a jig holding the workpiece in a grid pattern is supported horizontally and elastically at the tip of the rotary link, and the workpiece is moved in an arc shape around the pivot axis at the welding position together with the jig. The electrodes are aligned with the electrode positions of the spot welding machine, and welding is performed by sandwiching the electrodes from above and below at the intersection of the workpieces.

[Example] This will be explained with reference to an embodiment shown in the drawings.

1 has a swing link 2 and a pivot 3 on this swing link.
The rotation link 4 attached with the rotation link 4 and the rotation link 4
The robot is equipped with an operating lever 5 for rotating the robot, and a workpiece support 6 attached to the tip of a rotating link 4. Reference numeral 61 indicates a support frame for the workpiece support; 62 indicates a mounting plate that slides on the support frame and is fixed with screws 63; 64 indicates an adjustment frame that is elastically supported by the mounting plate 62 via a spring 65; and 66 The mounting interval can be adjusted according to the jig 7 using support claws mounted on the adjustment frame 64. 67 is rotatably attached to the adjustment frame with a jig holder.

As shown in FIG. 3, the jig 7 has a support groove 72 provided on the inner surface of a frame 71, into which a workpiece 8 is inserted and fitted. 9 is a spot welding machine, 91, 92
9 is an arm of the welding machine 9, 93 is an upper electrode, 94 is a lower electrode, and 95 and 96 are actuators for vertically moving the electrodes 93 and 94, respectively.

Adjustment frame 64 and support claw 66 of workpiece support 6
The mounting position of the jig 7 is adjusted according to the size of the jig 7, and the workpiece 8 cut to a predetermined size is placed in the support groove 7.
The jig 7 inserted into the workpiece 2 and held in a lattice shape is placed on the support claws 66 of the workpiece support 6 and fixed with a jig presser 67. When the jig 7 is placed in this manner, the robot 1 moves the workpiece support 6 to the electrode position of the spot welding machine 9 using the swivel link 2 and the swivel link 4 under taught control.
The intersecting part of the workpiece 8 to be welded first is connected to the electrodes 93, 9.
Match position 4.

When the operation of the robot is stopped, the electrodes 93 and 94 of the spot welding machine 9 are connected to the actuators 95 and 96.
The workpiece 8 is lowered and raised to perform welding by sandwiching the intersection of the workpieces 8.

Note that if the position of each intersecting part is not flat due to bending of the workpiece 8 or the like and the height varies, for example, if it is raised higher than other intersecting parts, the upper electrode 93
The jig 7 descends and hits the lifted workpiece, and the jig 7
The entire body is pushed down by the spring 65 to bring the intersecting portion into contact with the lower electrode, thereby achieving good welding.

When one welding, for example, the welding shown in FIG.
The upper and lower electrodes are separated from the workpiece 8, and the operating lever 5 is used to rotate the rotation link 4 about the pivot 3 according to the distance between the workpiece 8 and the next intersecting part b. The jig 7 holding the is moved in an arc shape to align the next intersecting portion b lined up in the turning direction with the electrode position. Note that the positions of the intersecting parts a, b, c, etc. of the work 8 inserted into the jig 7 differ slightly from the pivot point 3 because the work is a straight line, and the positions of the intersecting parts a, b, c... Since the position of the rib is displaced on the line connecting the electrode and the pivot axis and deviates from the electrode position, the swing link 2 is rotated in accordance with this displacement to correct the displacement and welding is performed by sandwiching the welding between the electrodes. Welding of c, d, e, etc. is carried out in the same manner, and when the welding of the intersections of the rows arranged in the turning direction is completed, the turning link 2 is adjusted and the next row is welded in the same way.

[Effects of the present invention] As described above, the present invention provides a workpiece support device at the tip of the rotary link of a robot equipped with a rotary link 2 and a rotary link 4 pivotally supported by the rotary link 2, and a workpiece is inserted and held in the jig. The tool 7 is elastically supported by the workpiece support via a spring, and each intersecting part of the workpiece is rotated in an arc around the pivot point of the rotation link 4, thereby sequentially welding the electrodes for spot welding. At the same time, the upper and lower electrodes of the spot welding machine are moved relative to the workpiece to contact and separate from the workpiece, so each intersection of the workpiece can be moved by robot operation. The jig can be quickly and accurately sequentially delivered to the electrode position of the spot welding machine, automating the movement of the jig, saving labor and time, and because the jig moves in an arc with a pivot link. As shown in Fig. 5a, at the intersection c where the cross direction of the horizontal workpiece and the vertical workpiece held by the tool is on the axis of the rotation link, the electrode and the rotation center meet at the electrode position. At the crossing point that is perpendicular to the connecting line, but deviates from this position in the arc-shaped moving direction, the crossing direction of the work changes in the order of b, a, d, and e, and the electrode In contrast to the solid line when the contact state between the surface and the workpiece is at intersection point a, the intersecting direction of the workpiece at intersection point e is moved sequentially as shown by the dotted line to evenly wear out the electrode surface. I can do it. Also,
By separating the lower electrode together with the upper electrode, it is possible to prevent welding with the electrode, which tends to occur when welding reinforcing bars or the like where the surface of the workpiece is not smooth. In addition, even when the flatness of the welded part cannot be maintained due to bending of the workpiece, etc., by elastically supporting the jig on the workpiece support, the contact condition with the electrode and the workpiece can be improved, and reliable welding can be performed. I can do it.

[Brief explanation of drawings]

FIG. 1 is a side view showing an embodiment of the present invention, with a portion shown in cross section. Fig. 2 is a plan view with the upper electrode removed, Fig. 3 is a perspective view showing a part of the jig, Fig. 4 is a sectional view taken along line A-A in Fig. 2, and Fig. 5 shows the welding state. FIG. 1 is a robot, 2 is a rotating link, 3 is a pivot, 4
is a rotation link, 5 is an operating lever, 6 is a workpiece support, 7 is a jig, 8 is a workpiece, 9 is a welding machine, 62 is a mounting plate, 64 is an adjustment frame, 65 is a spring, 66 is a support claw, 67 is a jig holder, 91 and 92 are arms, 9
3 is an upper electrode, 94 is a lower electrode, and 95 and 96 are actuators.

Claims (1)

[Claims] 1 Workpieces made of bar-shaped steel materials are arranged in a grid pattern,
In spot welding for welding the intersecting parts, a robot having a jig for holding the work in a grid pattern, a swing link, and a swing link pivotally supported by the swing link and having a work support at its tip; A spot welding machine is provided with an upper electrode and a lower electrode that are moved vertically in opposition to each other by actuators. At the electrode position, the work is moved along with the jig in an arc by rotation of the rotary link, and the intersecting parts of the work are sequentially aligned with the electrode position. A spot welding device for grid-like workpieces, which welds by sandwiching the ribs.