Spot welder and work-piece welding method of spot welder

Abstract

To easily fix a work-piece and a jig to shorten a setup time and improve processing efficiency.SOLUTION: A spot welder 1 comprises a plurality of welding guns 3, 5, a table 6 on which a work-piece is placed, and a control part 7 which executes processing for welding the work-piece. When a change-over switch 22 is operated whereby any one of a plurality of welding guns is selected and a pressurizing switch 15, 20 is operated, the control part 7 causes the welding guns, which have not been selected by the change-over switch 22, to perform a pressurizing operation for the table 6, and when a welding switch 16, 21 is operated in the state that the pressurizing operation is performed, the control part causes the welding gun selected by the change-over switch 22 to weld the workpiece placed on the table 6.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a spot welding machine and a workpiece welding method using the spot welding machine. [Background technology]

[0002] Patent Document 1 describes a spot welding machine in which a workpiece is placed on a flat plate electrode and spot welding is performed using multiple welding guns. With this type of spot welding machine, setup work is required to fix the workpiece and the jig. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-183421 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the setup work for fixing the workpiece and the jig can be complicated, which increases the setup time and reduces the machining efficiency. [Means for solving the problem]

[0005] A first aspect of one or more embodiments is a spot welding machine comprising a plurality of welding guns, a table on which a workpiece is placed, a selector switch for selecting one of the plurality of welding guns, a pressure switch operated when applying pressure to the workpiece, a welding switch operated when welding the workpiece, and a control unit for executing a process for welding the workpiece, wherein the control unit operates the selector switch to select one of the plurality of welding guns, and when the pressure switch is operated, causes a welding gun not selected by the selector switch to perform a pressure operation on the table, and when the welding switch is operated while the pressure operation is being performed, causes the welding gun selected by the selector switch to weld the workpiece placed on the table.

[0006] A second aspect of one or more embodiments is a workpiece welding method for a spot welding machine having a plurality of welding guns and a table on which a workpiece is placed, in which a selector switch for selecting one of the plurality of welding guns is operated to select one of the plurality of welding guns, and when a pressure switch operated to apply pressure to the workpiece is operated, the welding gun not selected by the selector switch applies pressure to the table, and when a welding switch operated to weld the workpiece is operated while the pressure application is being performed, the welding gun selected by the selector switch welds the workpiece placed on the table. [Effects of the Invention]

[0007] According to one or more embodiments of the spot welding machine and welding method, the workpiece and the jig can be easily fixed, thereby reducing setup time and improving processing efficiency. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing the structure of a spot welder according to a first embodiment. [Figure 2]FIG. 2 is a perspective view showing the structure of a handle of a vertical gun provided in the spot welding machine according to the first embodiment. [Figure 3] FIG. 3 is a diagram showing the structure of a handle of a horizontal gun provided in the spot welding machine according to the first embodiment. [Figure 4] FIG. 4 is a flowchart showing a processing procedure for welding a workpiece by the spot welder according to the first embodiment. [Figure 5] FIG. 5 is a diagram for explaining a method for welding a workpiece using the spot welder according to the first embodiment. [Figure 6] FIG. 6 is a diagram for explaining a method for welding a workpiece by the spot welder according to the first embodiment. [Figure 7] FIG. 7 is a diagram for explaining a method for welding a workpiece by the spot welder according to the first embodiment. [Figure 8] FIG. 8 is a diagram for explaining a method for welding a workpiece by a spot welder according to the second embodiment. [Figure 9] FIG. 9 is a diagram for explaining a method for welding a workpiece by a spot welder according to the second embodiment. [Figure 10] FIG. 10 is a diagram for explaining a method for welding a workpiece by a spot welder according to the second embodiment. [Figure 11] FIG. 11 is a diagram for explaining a method for welding a workpiece by a spot welder according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] [First embodiment] Hereinafter, a spot welder and a workpiece welding method therefor according to this embodiment will be described with reference to the drawings.

[0010] [Spot welding machine structure] The structure of a spot welder according to this embodiment will be described with reference to Fig. 1. Fig. 1 is a perspective view showing the structure of the spot welder according to this embodiment. As shown in Fig. 1, spot welder 1 includes a plurality of welding guns including a vertical gun 3 and a horizontal gun 5, a table 6 on which workpieces are placed, and a control unit 7 that executes the process of welding the workpieces. In addition, spot welder 1 includes an operation pendant 8 and a foot switch 9.

[0011] The vertical gun 3 is a welding gun that extends vertically relative to the table 6. Specifically, the vertical gun 3 is attached to an arm 11 that extends horizontally from a support 10 that is installed vertically relative to the floor surface, and extends downward from the arm 11. The arm 11 rotates horizontally around the support 10 as its axis of rotation, and the vertical gun 3 can move horizontally along the arm 11 from the tip of the arm 11 toward the support 10. The vertical gun 3 can also move up and down vertically. Therefore, the vertical gun 3 can move freely in both the vertical and horizontal directions.

[0012] The vertical gun 3 is connected to a power supply device (not shown) by a cable and functions as an upper electrode for spot welding. When welding, the vertical gun 3 descends to apply pressure to the workpiece, and then a welding current is passed through it to weld the workpiece.

[0013] The vertical gun 3 is equipped with a handle 13 that an operator holds when operating the vertical gun 3. The handle 13 is provided in the vertical center of the vertical gun 3, and as shown in FIG. 2, it is equipped with a grip 14 that an operator holds, a pressure switch 15, and a welding switch 16.

[0014] The grip 14 is a rod-shaped member that protrudes in three directions, and is held by an operator when moving the vertical gun 3.

[0015] The pressure switch 15 is a switch that is operated when applying pressure to the workpiece, and is provided on the handle 13. When the pressure switch 15 is turned on, the vertical gun 3 descends and applies pressure to the table 6. The vertical gun 3 also applies pressure before welding, so when the pressure switch 15 is turned on, the same pressure operation as when welding is performed.

[0016] Welding switch 16 is a switch that is operated when welding a workpiece, and by turning on welding switch 16, vertical gun 3 descends and applies pressure to the workpiece, and then welding current is applied to perform spot welding. However, welding may also be performed by stepping on foot switch 9 instead of welding switch 16.

[0017] The horizontal gun 5 is a welding gun that extends horizontally relative to the table 6. Specifically, the horizontal gun 5 is attached to an arm 17 that extends horizontally from a support 10 that is installed perpendicular to the floor surface, and extends downward from the arm 17, with its lower end extending horizontally. The arm 17 rotates horizontally around the support 10 as its axis of rotation, and the horizontal gun 5 can move horizontally along the arm 17 from the tip of the arm 17 toward the support 10. The horizontal gun 5 can also move up and down vertically. Therefore, the horizontal gun 5 can move freely in both vertical and horizontal directions.

[0018] The horizontal gun 5 is connected to a power supply device (not shown) by a cable and functions as an upper electrode for spot welding. When welding, the horizontal gun 5 descends to apply pressure to the workpiece, and then a welding current is passed through it to weld the workpiece.

[0019] The horizontal gun 5 is equipped with a handle 18 that an operator holds when operating the horizontal gun 5. The handle 18 is provided at the part of the horizontal gun 5 that extends downward from the arm 17 and bends horizontally, and as shown in Figure 3, the handle 18 is equipped with a grip 19 that an operator holds, a pressure switch 20, and a welding switch 21.

[0020] Grip 19 is provided on the horizontal opposite side of the tip of horizontal gun 5, and is held by the operator when moving horizontal gun 5. A pressure switch 20 and a welding switch 21 are each provided on grip 19 of handle 18. Since pressure switch 20 and welding switch 21 have the same functions as pressure switch 15 and welding switch 16, respectively, a description thereof will be omitted.

[0021] The table 6 has a flat electrode on its upper surface, which is grounded and functions as the lower electrode for spot welding. When spot welding is performed, a workpiece is placed on the table 6, and the worker operates the vertical gun 3 or horizontal gun 5 to perform the spot welding.

[0022] The operation pendant 8 is equipped with a display screen and multiple operation buttons, and in particular, a selector switch 22. The selector switch 22 is a switch for selecting one of the multiple welding guns, the vertical gun 3 and the horizontal gun 5, and a welding current is passed through the selected welding gun.

[0023] The control unit 7 executes a process for welding the workpieces. Specifically, when the selector switch 22 is operated to select either the vertical gun 3 or the horizontal gun 5 and the pressure switch 15 or 20 is operated, the control unit 7 causes the welding gun not selected by the selector switch 22 to apply pressure to the table 6. In particular, the pressure operation can be performed to pressurize the workpiece or to pressurize the jig, but the pressure operation in this embodiment is an operation in which the welding gun not selected by the selector switch 22 applies pressure to the workpiece placed on the table 6. In other words, when the pressure switch of the welding gun not selected by the selector switch 22 is turned on, the control unit 7 lowers the welding gun to apply pressure to the workpiece.

[0024] When welding switch 16 or 21 is operated while the pressurizing operation is being performed, control unit 7 causes the welding gun selected by selector switch 22 to weld the workpiece placed on table 6. In other words, when the welding switch of the welding gun selected by selector switch 22 is turned on, control unit 7 causes the selected welding gun to pass a welding current through and weld the workpiece.

[0025] The control unit 7 is configured by a computer having a memory, a processor such as a CPU (Central Processing Unit), and various interfaces. The memory and various interfaces are controlled by the processor. The control unit 7 controls the welding of the workpiece by having the processor execute a program stored in the memory. The welding conditions are created by the operation pendant 8 and transferred to the control unit 7 via communication.

[0026] Foot switch 9 is a switch that is operated when welding a workpiece, and when an operator steps on foot switch 9, a welding current is passed through the welding gun selected by selector switch 22, thereby performing spot welding. When welding, welding can be performed using welding switch 16 or 21, or welding can be performed using foot switch 9 by switching between them.

[0027] [Work welding method] Next, a method for welding a workpiece using the spot welder 1 according to this embodiment will be described. Fig. 4 is a flowchart showing the procedure of the method for welding a workpiece. In particular, this embodiment will describe a case where spot welding is performed while the workpiece is fixed by a welding gun.

[0028] As shown in Fig. 4, in step S10, the workpieces are set on the table 6. For example, as shown in Fig. 5, the worker first places the workpiece W1 on the table 6, and then places and positions the workpiece W2 at the assigned position on the workpiece W1.

[0029] In step S20, the operator operates selector switch 22 to select a welding gun to be used for welding from among a plurality of welding guns. In this embodiment, since spot welder 1 is equipped with vertical gun 3 and horizontal gun 5, the operator switches selector switch 22 to select one of the welding guns. Here, the case where horizontal gun 5 is selected will be described. When horizontal gun 5 is selected, a setting is made so that a welding current flows from the power supply device to horizontal gun 5.

[0030] In step S30, the welding gun that was not selected in step S20 is used to apply pressure to the workpiece. In the pressure application operation of this embodiment, the welding gun applies pressure to the workpiece, so the operator moves the unselected vertical gun 3 to pressure application position P1 on the workpiece W2 shown in FIG.

[0031] Then, the worker brings the vertical gun 3 close to the pressure application position P1 of the workpiece W2 and turns on the pressure application switch 15. When the pressure application switch 15 is operated, the control unit 7 lowers the vertical gun 3 to apply pressure to the workpiece W2. The pressure application at this time is the same as the pressure application performed before applying a welding current when welding.

[0032] In step S40, the workpiece is welded using the welding gun selected in step S20. The worker moves the selected horizontal gun 5 to welding position P2 shown in Figure 5, brings it close to welding position P2, and turns on welding switch 21. At this time, the worker may step on foot switch 9 instead of welding switch 21.

[0033] When the welding switch 21 is operated while the vertical gun 3 is applying pressure in this manner, the control unit 7 causes the horizontal gun 5 selected by the selector switch 22 to weld the workpiece W2 placed on the table 6. Specifically, the control unit 7 lowers the horizontal gun 5 to apply pressure to the welding position P2 of the workpiece W2, and then applies a welding current to the horizontal gun 5 to perform welding. When the workpieces W1 and W2 are welded in this manner, the workpiece welding process according to this embodiment is completed.

[0034] In the above-described embodiment, the workpiece W2 is described as being flat, but welding is possible even when the workpiece W2 is not flat. For example, as shown in Fig. 6, even when the workpiece W2 has a step, it is possible to apply pressure to the pressure position P1 with the vertical gun 3 and weld the welding position P2 with the horizontal gun 5. Furthermore, as shown in Fig. 7, even when the workpiece W1 has a step, welding is possible in the same way.

[0035] Furthermore, in the above-described embodiment, welding is performed using the horizontal gun 5, but welding can also be performed using the vertical gun 3. For example, if it is necessary to weld the pressurized position P1 after welding the welding position P2, pressurize the position P2 with the horizontal gun 5 and weld the position P1 with the vertical gun 3, and then weld the workpieces W1 and W2 without moving them.

[0036] [Effects of the first embodiment] As described above in detail, in spot welder 1 according to this embodiment, when selector switch 22 is operated to select one of a plurality of welding guns and pressure switch 15 or 20 is operated, control unit 7 causes the welding gun not selected by selector switch 22 to apply pressure to table 6. Then, when welding switch 16 or 21 is operated while the pressure operation is being performed, control unit 7 causes the welding gun selected by selector switch 22 to weld the workpiece placed on table 6. This allows the welding gun not being used for welding to be used to easily secure the workpiece or jig, thereby reducing setup time and improving processing efficiency.

[0037] Furthermore, in the spot welder 1 according to this embodiment, pressure switches 15, 20 are provided on handles 13, 18 that an operator holds when operating the welding gun. This allows the operator to operate pressure switches 15, 20 while holding handles 13, 18, thereby improving operability.

[0038] Furthermore, in the spot welding machine 1 according to this embodiment, the pressurizing operation is an operation of applying pressure to the workpiece placed on the table 6. This eliminates the need to prepare a jig for fixing the workpiece, thereby reducing the effort and cost required to prepare the jig.

[0039] [Second embodiment] A spot welder and a workpiece welding method therefor according to this embodiment will be described below with reference to the drawings. In the drawings, identical parts are designated by the same reference numerals, and detailed description thereof will be omitted. In the first embodiment, the workpiece is pressurized in the pressurizing operation, but in this embodiment, the jig is pressurized, which is different. The structure of the spot welder 1 according to this embodiment is the same as that of the first embodiment, and detailed description thereof will be omitted.

[0040] [Work welding method] Next, a method for welding workpieces using the spot welder 1 according to this embodiment will be described. In this embodiment, the same processing as that in the flowchart shown in FIG. 4 of the first embodiment is performed, except for the pressurizing operation in step S30. The pressurizing operation in this embodiment is an operation in which the welding gun not selected by the selector switch 22 presses the jig placed on the table 6. Therefore, only step S30 will be described, and descriptions of the other steps will be omitted.

[0041] In step S30, a pressure operation is performed using the welding gun that was not selected in step S20. In the pressure operation of this embodiment, pressure is applied to the jig using the welding gun. For example, as shown in FIG. 8, workpiece W1 is supported by jig 30, and workpiece W2 is welded with pressure applied to jig 30. Therefore, the worker moves vertical gun 3, which was not selected in step S20, to pressure position P1 shown in FIG. 8.

[0042] Then, the worker brings the vertical gun 3 close to the pressure position P1 of the jig 30 and turns on the pressure switch 15. When the pressure switch 15 is operated, the control unit 7 lowers the vertical gun 3 to apply pressure to the jig 30. Thereafter, the horizontal gun 5 welds the welding position P2, and the welding process of the workpiece according to this embodiment is completed.

[0043] Furthermore, it is possible to apply pressure to weld jigs of different shapes in the same way. For example, as shown in Figure 9, when using a jig 32 bent at a right angle, a box-shaped workpiece W2 is placed on a flat workpiece W1 and positioned using the jig 32. Then, pressure is applied to the pressure position P1 of the jig 32 with the horizontal gun 5 to fix the jig 32, and in this state, welding position P2 within the workpiece W2 is performed with the vertical gun 3.

[0044] Furthermore, as shown in Fig. 10, it is also possible to use a flat jig 34 with holes drilled at predetermined positions. When using the jig 34, an L-shaped workpiece W2 is placed on a flat workpiece W1, and then the jig 34 is placed on top of that to position it. Then, pressure is applied to a pressure position P1 of the jig 34 with the horizontal gun 5 to fix the jig 34. In this state, the position of the hole 35 in the jig 34 becomes the welding position P2, and this welding position P2 is then welded with the vertical gun 3.

[0045] It is also possible to weld a nut instead of the workpiece W2. For example, as shown in Figure 11, a jig 34 is placed on a flat workpiece W1 and positioned, and a nut 36 is set in a hole 35 of the jig 34. Then, pressure is applied to a pressure position P1 of the jig 34 with the horizontal gun 5 to fix the jig 34, and in this state the nut 36 is welded with the vertical gun 3.

[0046] When welding the nut 36, it is preferable to use the vertical gun 3. The vertical gun 3 applies pressure vertically downward before welding, whereas the horizontal gun 5 applies pressure in an arc-shaped downward direction. Therefore, when the nut 36 is welded using the horizontal gun 5, the nut 36 may become misaligned. Therefore, to prevent the nut 36 from becoming misaligned, it is preferable to use the vertical gun 3 for welding.

[0047] [Effects of the second embodiment] As described above in detail, in the spot welding machine 1 according to this embodiment, the pressure application operation is an operation of applying pressure to the jig placed on the table 6. This allows the jig to be easily fixed, thereby shortening the setup time and improving the processing efficiency.

[0048] Although the embodiments of the present invention have been described above, the descriptions and drawings that form part of this disclosure should not be understood to limit the present invention. Various alternative embodiments, examples, and operating techniques will become apparent to those skilled in the art from this disclosure. [Explanation of symbols]

[0049] 1 Spot welding machine 3 Vertical Gun 5 Horizontal Gun 6 tables 7 Control Unit 8 Operation pendant 9 Footswitch 10 posts 11, 17 Arms 13, 18 Handle 14, 19 Grip 15, 20 Pressure switch 16, 21 Welding switch 22 Selector switch 30, 32, 34 Jig 35 holes 36 Nut P1 pressure position P2 welding position W1, W2 work

Claims

1. A plurality of welding guns; a table on which a workpiece is placed; a selector switch for selecting one of the plurality of welding guns; a pressure switch that is operated when pressurizing the workpiece; a welding switch that is operated when welding the workpiece; a control unit that executes a process of welding the workpiece, The control unit When the selector switch is operated to select one of the plurality of welding guns and the pressure switch is operated, the welding gun not selected by the selector switch is caused to perform a pressure operation against the table; When the welding switch is operated while the pressurizing operation is being performed, the welding gun selected by the changeover switch is caused to weld the workpiece placed on the table. Spot welding machine.

2. The pressure switch is provided on a handle that an operator holds when operating the welding guns.

2. The spot welder according to claim 1.

3. The pressurizing operation is an operation in which the welding gun not selected by the changeover switch presses the workpiece placed on the table.

3. The spot welder according to claim 1 or 2.

4. The pressurizing operation is an operation in which the welding gun not selected by the selector switch presses the jig placed on the table.

3. The spot welder according to claim 1 or 2.

5. A workpiece welding method for a spot welder equipped with a plurality of welding guns and a table on which a workpiece is placed, comprising: By operating a selector switch for selecting one of the plurality of welding guns, one of the plurality of welding guns is selected; When a pressure switch that is operated to apply pressure to the workpiece is operated, the welding gun that is not selected by the changeover switch performs a pressure operation on the table, When a welding switch that is operated when welding the workpiece is operated while the pressurizing operation is being performed, the welding gun selected by the changeover switch welds the workpiece placed on the table. How to weld workpieces using a spot welding machine.

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