JPH0248144Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to an automatic spot welding device that is combined with a so-called robot or the like.

(Prior art) Conventionally, spot welding guns mounted on robots, for example, generate inertial shock due to the gun's own weight at the point where the workpiece is pressure welded between spot electrodes, which may impair welding quality. , harmful impact force was applied to the robot side, which was undesirable.

To solve this problem, we designed a soft mount that allows the welding gun to slide in the direction of applying pressure to the electrode, and suppresses this sliding with elastic force, so that the aforementioned impact is absorbed by this elastic force. There was something called a method.

However, although this method absorbs the impact at the point of impact, the gun may slide even when the robot is running, which is harmful in high-speed operations. That is, even when the robot moved at high speed and arrived at the welding position, the gun did not stop vibrating, making it impossible to immediately start welding.

As a spot welding apparatus that solves this problem, for example, the apparatus described in Japanese Utility Model Application Laid-Open No. 1485-1985 is known.

This device includes a guide member that supports an electrode and is slidably provided on the main body, a spring that biases the guide member in a pressing direction, and a guide member that resists the elastic force of the spring. The structure includes a locking mechanism that locks the device to the main body.

Therefore, when the robot is running, the locking mechanism can be activated to lock the guide member and prevent the electrode from moving.

However, in such conventional devices, the locking mechanism is configured to move and lock the guide member against the elastic force of the spring, so the locking mechanism requires an output sufficient to resist the elastic force. , there is a problem that the structure becomes complicated because a configuration that only moves the guide member is required.
Moreover, since it takes time to move the guide member against the spring, there is a problem in that the time required for locking becomes longer and, as a result, the welding cycle becomes longer.

(Purpose of the invention) The present invention was made to solve the above-mentioned problems, and its purpose is to provide a locking means to prevent the soft-mounted electrodes from moving. An object of the present invention is to provide an automatic spot welding device that can reduce the output of the locking means, simplify the structure, and shorten the time required for locking, while improving the efficiency of high-speed work in automatic spot welding. .

(Structure of the invention) In order to achieve this purpose, according to this invention,
Two spot electrodes provided opposite each other so that a workpiece to be welded can be welded under pressure from both sides, one arm that supports these electrodes, support means that supports this arm, and connection to this support means. a moving means for moving both electrodes and the arm along with the supporting means; and a moving means interposed between the front arm and the supporting means, the arm being slidable in the direction of pressurizing the spot electrode and the opposite direction with respect to the supporting means. a first spring provided between a member on the arm side of the slide means and a member on the support means side and biasing the arm side member to slide in the pressurizing direction; an elastic holding means capable of holding the arm at a predetermined neutral position where both springs are balanced with respect to the supporting means by a second spring manually biased in the opposite direction to the biasing direction; and between the arm and the supporting means. A lock means is provided at the neutral position and is capable of restricting sliding of the arm at the neutral position.

(Embodiments of the invention) Hereinafter, embodiments of the invention will be described in detail with reference to the drawings.
Note that the same reference numerals in each figure indicate similar objects.

FIG. 1 is a side view showing an embodiment of this invention.

According to the figure, two spot electrodes 1 and 2 facing each other for pressure welding the workpiece from both sides,
One arm 3 supporting these electrodes 1, 2
, a slide means 5 that allows the arm 3 to slide in the direction of pressurizing the spot electrodes 1 and 2 and the opposite direction thereof, and a support means that supports both the electrodes 1 and 2 and the arm 3 via the slide means 5. 6, and a moving means 7 connected to the supporting means 6 and for moving both the electrodes 1, 2 and the arm 3 together with the supporting means 6.

Further, the electrode 2 is made to protrude leftward in the figure by an air cylinder 4 incorporated in the arm 3, and is pressurized and energized to enable welding of the object to be welded.

Furthermore, the sliding means 5 is provided with locking means 8.

FIG. 2 shows a partially cutaway front view a and a cross-sectional view b taken along the line A-A of the slide means 5 of such a welding device.

According to the figure, the slide means 5 has three cylindrical guide rails 52a, 52b, and 52c built on slide rail mounting members 50 and 51 that are fixed to the arm 3 side and arranged in parallel with each other at a constant interval. has been done.

A slide support member 53 attached to the support means 6 side is mounted on the guide rails 52a, 52b, and 52c.

The slide support member 53 includes a single flat plate 531 and three blocks 5 fixed to the flat plate 531.
It is composed of 3a, 53b, and 53c. Further, each block 53a, 53b, 53c has through holes 53a1, 53b1, 53c1 through which guide rails 52a, 52b, 52c are inserted.

Since the slide means 5 is constructed as described above, the entire arm 3 is attached to the guide rails 52a, 52.
b, 52c, it can slide in the direction in which the electrode 2 is pressed and in the opposite direction (left and right directions in the figure).

The slide means 5 includes a block 53b, which is a member on the side of the support means 6, and an arm 3.
Slide rail mounting members 50, 5 which are side members
1, there is a first coil spring 54a that biases the slide rail mounting member 50 in the direction of pressing the electrode 2, and a first coil spring 54a that biases the slide rail mounting member 51 in the direction of pressing the electrode 2.
An elastic holding means 54 is provided, which consists of a coil spring 54b that urges in a direction opposite to the pressing direction.

That is, this elastic holding means 54 supports the slide support member 53 at a neutral position where both springs 54a and 54b are balanced, and thereby both electrodes 1 and 2
and arm 3 is supported in a neutral position.

A locking means 8 is attached to the block 53c.

This locking means 8 has an air cylinder 80 and a movable head 81, and the tip 81a of the head 81 has a conical shape. This conical portion 81a
is the guide rail 52 placed in the neutral position.
It fits into the conical recess 52c1 of c to achieve a lock that restricts the sliding of the arm 3.

In the illustrated state, the head 81 is in the recess 52c.
1 and is in a locked state, and when the cylinder 80 is turned in the opposite direction and the head 81 is pulled down, the arm 3 is in a so-called soft mount state in which it can slide.

Therefore, in the above configuration, when the moving means 7 moves at high speed, the arm 3 is locked by the locking means 8, and when the moving means 7 stops and the welding process starts, the lock is released. This may be a so-called soft mount.

FIG. 3 shows a pressurization system for accomplishing this operation.

That is, pressurized air from the pressure source 30 is sent into the pipe 32 or 33 by the switching valve 31, and the air is sent into the front chamber or rear chamber of each piston 4a, 80a of each cylinder 4, 80. The illustrated state is the pipe 33
Air is sent to the side, the piston 4a of the cylinder 4 is pulled down, and the electrode 2 at the tip of the piston rod 4b is pulled down, and the piston 80a of the cylinder 80 of the locking means 8 is pushed out to push out the piston rod 80b, as shown in FIG. This shows the case where the device is in a locked state. In order to release the locked state, air can be sent to the pipe 32 side using the switching valve 31.

Therefore, by controlling the switching valve 31 using the traveling command signal or the welding start signal of the moving means 7 (FIG. 1), the sliding means 5 is locked while the welding device is traveling, and the welding process is stopped. When entering, the slide means 5 can be unlocked and put into a so-called swift mount state.

As described above, in the spot welding apparatus of this embodiment, when locking is performed by the locking means 8, the guide rail 52c, which is a member on the arm 3 side, is placed in the neutral position by both springs 54a and 54b. Since the locking structure is such that there is no need to move the arm 3 against both springs 54a and 54b during locking, the output of the locking means 8 during locking can be small, and the configuration can be simplified. In addition, the arm 3 can be connected to the spring 5 in this way.
4a and 54b, the time required for locking is shortened, and the welding cycle can be shortened.

(Effects of the invention) As explained above, in the automatic spot welding device of the invention, the arm is locked at the neutral position where the urging forces of the two springs are balanced.
When locking, there is no need to move the arm against the spring, the output of the locking means during locking can be small, and the configuration can be simplified. Since there is no need to stroke the arm against the spring, the time required for locking is shortened.
The effect is that the welding cycle can be shortened.

[Brief explanation of the drawing]

Figure 1 is a side view of an embodiment of this invention, Figure 2a
2 is a front view of the main part of the embodiment, FIG. 2b is a sectional view of the main part of the embodiment, and FIG. 3 is a system diagram of the main part of the embodiment. 1, 2...Spot electrode, 3...Arm, 4...
...Cylinder, 5...Sliding means, 6...Supporting means, 7...Moving means, 8...Lock means, 54...
...Elastic holding means, 54a...Spring, 54b
……spring.

Claims (1)

[Claims for Utility Model Registration] Two spot electrodes that are provided facing each other so that a workpiece to be welded can be welded under pressure from both sides, one arm that supports these electrodes, and a support that supports this arm. a means for moving the electrodes and the arm together with the support means; a moving means for moving the electrodes and the arm together with the support means; a moving means interposed between the arm and the support means for moving the arm in a direction in which the spot electrode is pressed against the support means; and a slide means slidably supported in the opposite direction; and a slide means provided between an arm-side member and a supporting means-side member of the slide means to slide and bias the arm-side member in the pressurizing direction. an elastic holding means capable of holding the arm at a predetermined neutral position where both springs are balanced with respect to the supporting means by a first spring that slides and urges in a direction opposite to the direction of this urging; An automatic spot welding apparatus comprising: a locking means provided between the arm and the supporting means and capable of regulating sliding of the arm in the neutral position.