JPS61108479A - Spot welding device - Google Patents

Abstract

PURPOSE:To prevent a material to be welded from being deformed by welding, and to execute spot welding of high quality by attaching a cylinder to a passive electrode supporting means of a spot welding device, and always energizing an incompressible fluid upward as an operating fluid. CONSTITUTION:A material to be welded 13 on a base 12 is clamped by a fig 11 attached to an arm 10A of a material carrying-in and carrying-out robot 10. By turning the arm 10A, the work to be welded 13 is placed on the upper side of a passive electrode 5A of a spot welding device 1. The passive electrode 5A is energized upward by an incompressible fluid fed into a cylinder 5B for supporting the electrode, through a path 7 from a liquid feeding circuit 5C, and when the passive electrode 5A is depressed by a descent of the work 13 and has been positioned at a welding position, the descent of the passive electrode 5A is stopped by locking the cylinder 5B. Subsequently, a movable electrode 6A is depressed by a cylinder 6B, the work 13 is inserted and held by cooperating with the passive electrode 5A, and spot welding is executed.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention is a spot welding device, more specifically, a spot welding device that aims to improve quality by preventing workpiece deformation, and also absorbs wear of welding electrodes, workpiece loading errors, etc. This invention relates to a spot welding device that can perform proper welding.

(Prior Art) Conventionally, as this type of spot welding device, one shown in FIG. 6 is known.

In the same figure, reference numeral 20 denotes a C-shaped welding device main body, and the welding device main body 20 is erected on a floor surface 22 via, for example, an ico-fusing device 21t into which a matching spring (not shown) is inserted. The upper arm portion 20 is supported by the column 23.
An upper electrode 25 is movably attached to the tip of A via a cylinder 24, and a lower electrode 26 facing the upper part 25 is fixed to the tip of the lower arm part 20B.

In the spot welding apparatus configured in this way, the 7-k is carried into the carry-in position by a carry-in device (not shown),
When the workpiece is held on the jig, the upper electrode 25 is lowered by the operation of the cylinder 24 and comes into contact with the upper surface of the workpiece at the welding position.

Furthermore, by operating the cylinder 24, the upper electric current #M2
5 presses the upper surface of the welding position of the workpiece, and the welding device is lifted against the spring force of the equalizing device 21, whereby the lower electrode 26 comes into contact with the lower surface of the welding position of the workpiece, and the lower electrode 26 and the upper electrode 25 Spot welding is performed by holding the workpiece between the two and applying electricity.

However, in the conventional spot welding device described above, the spring force of the equalizing device #t21 is set to be considerably large because the heavy device main body 20t needs to be supported by the pillar 23 without swinging. In order to lift the weld into the apparatus main body 20, the upper electrode 25 uses a large pressing force to press against the upper surface of the welding position of the workpiece, which pushes down the welding position of the workpiece and deforms it, degrading the quality. I have a problem.

In addition, when the lower electrode 26 is worn out due to polishing and the amount of upward movement of the apparatus main body 20 becomes large, or when an error occurs in the loading position of the workpiece and the amount of upward movement of the apparatus main body 20 becomes large, etc. The problem is that the upper electrode 25 does not have the function of absorbing wear of the electrode 26 and errors in the loading position, and the pressing force of the upper electrode 25 against the workpiece becomes even greater, resulting in increased deformation of the workpiece.

(Purpose of the Invention) This invention was made to solve the above-mentioned conventional problems, and it aims to improve quality by preventing workpiece deformation, and also absorbs welding electrode wear, workpiece loading errors, etc. The object is to provide a spot welding device that can perform proper welding.

(Structure of the Invention) To achieve the above object, the present invention includes a main body of a device for spot welding all the workpieces held on a jig, a passive electrode is attached, and a non-compressible fluid such as antifreeze or oil is used as a working fluid. It has a cylinder that is normally biased in the extension direction and is pushed back by contacting the passive electrode when the workpiece is set on the jig, and the fluid supply circuit of the cylinder has a cylinder that is pressed back when the workpiece is set on the jig. Passive electrode support means provided with a switching valve for locking the cylinder and attached to the main body of the device, and a passive electrode provided opposite to the passive electrode support means, supporting the movable electrode with the cylinder and locking the rework. and movable electrode support means for holding the movable electrode.

(Example) .

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a side view showing an embodiment of a spot welding device according to the present invention. In the same figure, 1 is a welding device main body, and the welding device It is supported by a column 4 erected on a surface 3, and is formed into a substantially C-shape having an upper arm part IA and a lower arm part IB.

Reference numeral 5 indicates a passive electrode support means, and reference numeral 6 indicates a movable electrode support means. The passive electrode support means 5 consists of a passive type @i5A, a cylinder 5B, and a fluid supply circuit 5C. The movable electrode support means 6 consists of a movable electrode 6A and a cylinder 6B. Become.

The passive electrode support means 5 is provided at the tip of the lower arm part IB of the device main body 1, and a passive type W5A is attached to the cylinder 5B.The cylinder 5B uses an incompressible fluid such as antifreeze or oil μ as a working fluid. It is normally biased in the stretching direction, and in this embodiment it is biased upward.

A fluid supply circuit 5C is connected to the cylinder 5B, and the fluid supply circuit 5C includes a switching valve 51 and a hydraulic/pneumatic converter 52 connected in series to the switching valve 51.

The hydraulic/pneumatic converter 52 is connected to the front chamber 5 by a piston 52A.
The passage 7, which is partitioned into a rear chamber 52b and a rear chamber 52b and communicates the front chamber 52a with the cylinder 5B, is filled with an incompressible fluid such as the antifreeze or oil μ, and a switching valve 51.
is interposed.

Further, the rear chamber 52b of the hydraulic/pneumatic converter 52 has a passage 8t.
The air pressure in the passage 8 acts on the incompressible fluid through the piston 52Ae, thereby forcing it upwardly through the cylinder 5t.

Note that the air pressure in the passage 8 is set to such a level that the liquid pressure in the passage 7 supports the weight of the passive electrode 5A.

Reference numeral 10 indicates a robot for loading and unloading, and its arm portion 10
A jig 11 is attached to the tip of A, and the stand 12 is opened and closed by the clamp cylinder IIA provided on the jig 11.
A workpiece 13 placed thereon is attached to and detached from the jig 11.

In the above configuration, the workpiece 13 placed on the table 12 in FIG. Robots) By the operation of 10, #! As shown in FIG. 2, the workpiece 13 is carried into the carrying position corresponding to the upper side of the passive chamber @5A.

Next, by the operation of loading/unloading robot IO,
The workpiece 13 clamped on the jig 11 is lowered. In this case, the hydraulic pressure of the cylinder 5B biasing the passive electrode 5Ai upward is large enough to support the weight of the passive chamber [5A], so the passive electrode 5A is pushed down by the lowering of the workpiece 13, and the workpiece 13 is lowered to the welding position shown in FIG. At this time, when the pick and workpiece 13 are positioned at the welding position, the switching valve 51 shown in FIG. 1 is activated!
The cylinder 5B is switched as shown in Fig. 4 to lock the passive electrode 5A to stop the lowering of the passive electrode 5A, and then the cylinder 6Bt in Fig. 1 is activated to push down the movable electrode 6A, and the passive electrode 5A is switched as shown in Fig. 5. In cooperation with the workpiece 13f, spot welding is performed by holding the workpiece 13f.

After spot welding is completed, the cylinder 6B (first @) is operated to raise the movable electrode 6A, and then the loading/unloading robot 10 is operated to carry out the workpiece 13 from the welding completion position, and at the same time, as shown in FIG. The switching valve 51 is switched as shown in FIG.
At-raise and return to prepare for next welding.

In this way, the hydraulic pressure of the incompressible fluid held in the standby position of the passive electrode 5At-t41 is set to a low pressure enough to support the weight of the passive electrode 5A, and the workpiece 13 is
After coming into contact with A, the passive electrode 5A is pushed back to the welding position by the weight of the workpiece 13,
And when the positioning of the workpiece 13 is completed, the cylinder 5
Et-locks and passive electrode 5At-stops, and in this position the movable electrode 6B is pressed against the workpiece 13 for welding, so no large force is applied to the workpiece 13, so the workpiece 13 Not deformed.

Moreover, even if the passive electrode 5A becomes shorter due to polishing,
The workpiece 13 only shortens the length of pushing down the passive electrode 5A to the welding position, and even if the movable electrode 6A is shortened by being polished, the length of the movable electrode 6At pushed down by the cylinder 6A only increases. As a result, the amount of wear on both electrodes 5A and 6A can be absorbed, so that the workpiece 13 is not deformed as in the conventional case.

Furthermore, a slight error occurs in the loading position of the workpiece 13,
Even if the amount of movement to reach the welding position changes, the workpiece 13 is not deformed.

In the above embodiment, the workpiece 13t' is held by the jig 11 attached to the tip of the arm 10A of the loading/unloading robot 10.
This invention is not limited only to the above embodiments,
A separate jig 1ift may be arranged near the welding apparatus main body 1, and the workpiece 13t may be held and positioned on this jig 11.

(Effects of the Invention) As explained above, according to the present invention, it is possible to prevent workpiece deformation and improve quality, and also absorb wear of welding electrodes, workpiece loading errors, etc. proper welding.

[Brief explanation of drawings]

Fig. 1 is a side view showing an embodiment of the spot welding device according to the present invention, Fig. 2 is a side view showing the next state after the workpiece has been carried into the carry-in position, and Fig. 3 is a side view showing the next state when the workpiece has been positioned at the welding position. FIG. 4 is an explanatory diagram showing the switching state of the switching valve, FIG. 5 is a side view during spot welding, and FIG. 6 is a side view showing an example of a conventional spot welding device. 1... Device main body, 5... Passive electrode support means, 5A.
-Passive electrode, 5B...Cylinder, 5C...Fluid supply circuit, 6...Movable electrode support means, 6A...Movable electrode, 6B...Cylinder, 51...Switching valve. 414 Figure 5 7 7
l Figure 6 Procedural Amendment 1, Indication of Case Patent Application No. 59-227248 2, Title of Invention Spot Welding Device 3, Relationship with the person making the amendment Patent Applicant Address Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture 3rd and 1st name
(313) Mazda Motor Corporation 4, agent postal code 5! i. 5. Date of amendment order Voluntary 6. Subject of amendment 7. Contents of amendment A. Specification: (1) Page 5, lines 13 to 14; "Equalizing with a balance spring (not shown) inserted. ``Support WtJ'' is corrected to ``supporting member.''that's all

Claims (1)

[Claims] (1) A device for spot welding workpieces held on a jig, in which a device body and a passive electrode are attached, and an incompressible fluid is used as a working fluid and is normally biased in the direction of extension to weld the workpieces in the jig. The workpiece has a cylinder that is pushed back by contacting the passive electrode when the workpiece is set on the tool, and the fluid supply circuit of the cylinder is provided with a switching valve that locks the cylinder when the positioning of the workpiece is completed. A passive electrode support means attached to the device main body, and a movable electrode support means provided opposite to the passive electrode support means, supporting the movable electrode with a cylinder and clamping the workpiece together with the locked passive electrode. A spot welding device characterized by: