JPH05169273A - Equalizing device for spot welding gun - Google Patents

Abstract

PURPOSE:To provide the equalizing device of the spot welding gun on which the equalizing device is operated normally even when the position of the spot welding gun is changed. CONSTITUTION:The inclined position of the welding gun 10 is detected by a position detector 2 provided on the weeding gun 10, the supply pressure to an equalizing cylinder 24 is changed by a pressure regulating valve 4 controlled by a cylinder pressure regulator 3 and the welding gun 10 is energized in the advancing direction of a movable electrode 14 by energizing force in accordance with a positional angle of the welding gun 10. Consequently, breaking of balance between the weight of the welding gun 10 due to inclining of the position of the welding gun 10 and the spring pressure of the equalizing device 1 to support the balance of the weight of the welding gun 10 is restored to the normal balance by attenuating the spring pressure by the energizing force of the equalizing cylinder 24. The equalizing device 1 is operated normally and deformation of materials to be welded is prevented disregarding the position of the welding gun 10 by this action.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding gun eco-raising device for a spot welding machine.

[0002]

2. Description of the Related Art In a spot welding machine, a movable electrode is driven to advance by a cylinder with respect to a fixed electrode arranged at a position opposite to the movable electrode, and a welding site of a workpiece is sandwiched between the fixed electrode and the movable electrode. Welding is performed by pressing and energizing. When clamping the work piece by the movable electrode and the fixed electrode, the welding gun is moved to prevent the work piece from deforming due to the difference between the center position of the clamp and the center position of the welding part. An eco-raising device is provided that supports the electrodes so that they can move in the forward and backward directions. FIGS. 3 and 4 show a conventional configuration of a spot welding gun provided with this eco-raising device. 3 (a) and 4 (a) are side view diagrams of the spot welding gun, showing a cylinder portion as a cross-sectional view, and FIGS. 3 (b) and 4 (b) are FIGS. 3 (a) and 4 ( a)
FIG. 2 is a configuration diagram of the eco-raising device 11 shown in FIG. 2 when viewed from the direction of the arrow B, similarly showing the cylinder portion as a sectional view. In FIG. 3, the welding gun 10 has a fixed electrode 13 attached to the tip of a gun arm 12, a movable electrode 14 is arranged at a position opposite to the fixed electrode 13, and the movable electrode 14 is attached to the fixed electrode 13 by an air cylinder 15. The welding gun 10 is configured so that it can be moved back and forth, and the welding gun 10 is attached to the spot welding machine body 16 via an eco-rising device 11. The eco-rising device 11 includes a rod 1 fixed to a support frame 18 provided in the spot welding machine body 16.
9 and 19 are slidably supported in the vertical direction in the figure.
That is, the rods 19 and 19 vertically penetrate through the brackets 20 a and 20 b fixed to the welding gun 10, and the welding gun 10 moves on the equalizing device 11 on the movable electrode 14.
It is supported so that it can move in the forward and backward directions. Coil springs 21 and 21 and coil springs 22 and 22 are arranged on the rods 19 and 19, and the bracket 20
brackets 20a, 20b at an intermediate position between the rods 19, 19 by which the coil springs 21, 22 and the weight of the welding gun 10 are balanced by urging the a, 20b in opposite directions.
Is configured to stop. The bracket 20b is provided with a stopper 23 for restricting the lower limit of sliding of the bracket 20b, and the bracket 20a is further contacted with the tip of a piston rod 25 of an eco-raising cylinder 24 provided above the support frame 18 to make the eco-friendly state. While air is being supplied into the rising cylinder 24 as shown in FIG. 3, the bracket 20a is urged downward. Therefore, while the bracket 20a is being biased by the eco-raising cylinder 24, the brackets 20a and 20b are biased to the restricting position of the stopper 23 and the coil springs 22 and 22 are compressed, as shown in FIG. 3B. It is in a state of When the movable electrode 14 is driven to advance by the air cylinder 15, the supply air switching valve 5 is switched to the exhaust direction. This allows the bracket 2 of the piston rod 25 to
The biasing force for 0a is released. At this time, the brackets 20a and 20b are raised to a position where the weights of the coil springs 21 and 22 and the welding gun 10 are balanced.
(See FIG. 4B.) When welding is performed on the object to be welded 17 by the welding gun 10 having the above-described configuration, the welding gun 10 moves the welding position of the object to be welded 17 by moving the welding machine body 16 (see FIG. 3). Position), as shown in FIG.
When the air of No. 4 is exhausted to release the bias to the bracket 20a, the welding gun 10 rises to a position where the elastic force of the coil springs 21 and 22 and the weight of the welding gun 10 are balanced. Therefore, the movable electrode 14 is moved by the air cylinder 15.
When the electrode is driven in the advancing direction, the fixed electrode 13 and the movable electrode 1
4 and the center position of the object to be welded 17 are different, the movable electrode 14 before the end of the clamp.
When the contact reaction force to the work piece 17 acts on the welding gun 10, the welding gun 10 moves on the rods 19, 19 of the eco-rising device 11, so that the center position of the clamp and the center position of the work piece 17 coincide with each other. As a result, the object to be welded 17 is clamped without being deformed.

[0003]

Since the weight of the welding gun 10 and the coil springs 21 and 22 are balanced in the conventional example structure of the above-mentioned eco-rising device, the welding gun 10 has a certain angle. When the welding posture is such that the weight is not leaned to the coil spring 22 by tilting as described above, for example, when the welding gun 10 is in the horizontal posture as shown in FIG. Since the balance between the springs 21 and 22 and the weight of the welding gun 10 becomes unbalanced, the coil spring 2
There is a problem that the spring pressures of 1 and 22 prevail, the eco-rising device does not operate normally, and deformation of the workpiece 17 is not prevented. In view of the above problems, the present invention provides an eco-rising device for a spot welding gun, which enables normal operation of the eco-rising device even when the position of the welding gun is more than an angle at which the eco-rising device does not operate. The purpose is to

[0004]

Means adopted by the present invention for achieving the above object are a cylinder for driving a movable electrode forward and backward with respect to a fixed electrode provided at a position facing the movable electrode, and the movable electrode. A spot welding gun including a fixed electrode and a fixed electrode is movably supported in an advancing / retreating direction of the movable electrode, and the spot welding gun is equipped with an equalizing cylinder for urging the spot welding gun in the axial direction of each electrode. In the gun eco-raising device, a posture detection means for detecting the inclined posture of the spot welding gun and a cylinder pressure control means for controlling the urging force of the eco-raising cylinder by a detection signal of the posture detection means are provided. It is configured as an eco-rising device for the characteristic spot welding gun.

[0005]

According to the present invention, the attitude detecting means provided in the welding gun detects the tilted attitude of the welding gun, and the cylinder pressure control means is operated by the detection signal to change the supply pressure to the economizing cylinder. The welding gun is biased in the advancing direction of the movable electrode by the biasing force according to the attitude angle of the welding gun. As a result, the unbalanced balance between the weight of the welding gun due to the inclination of the welding gun and the spring pressure of the eco-raising device that balances the weight of the welding gun can be reduced by the biasing force of the eco-raising cylinder. And restore balance. By this action, the eco-rising device operates normally regardless of the position of the welding gun, and the deformation of the workpiece is prevented.

[0006]

Embodiments of the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention. still,
The following examples are examples of embodying the present invention and do not limit the technical scope of the present invention. Figure 1
FIG. 2 is a configuration diagram of a welding gun equipped with an eco-raising device according to an embodiment of the present invention, and FIG. 2 is a configuration diagram showing a state in which an object to be welded is clamped by changing a posture of the welding gun. 1B and FIG. 2 are configuration diagrams of the eco-rising device in FIG. 1A and FIG.
It is shown as (b). Further, the same parts as those of the conventional example are designated by the same reference numerals, and the description thereof will be omitted. In FIG. 1, the welding gun 10 is provided with a posture detector 2 for detecting the posture angle of the welding gun 10. The posture detector 2 detects the posture angle of the welding gun 10 and inputs a detection signal to the cylinder pressure adjusting device 3. Eco Rising Device 1
The pressure regulating valve 4 is arranged between the eco-rising cylinder 24 provided in the
The pressure adjusting valve 4 is controlled by the cylinder pressure adjusting device 3 and adjusts the pressure of the air supplied to the ecological cylinder 24 according to the detection signal of the attitude detector 2. In the above configuration, the pressure regulating valve 4 remains fully open in a state in which the weight of the welding gun 10 and the coil springs 22, 22 of the eco-rising device 1 are in a balanced state, and the eco-rising cylinder 24 is a conventional example. The operation is the same as that shown in (1), air is exhausted by the switching valve 5 when the workpiece 17 is clamped by the welding gun 10, and air is supplied in other states, and the bracket 20
A is pressed to urge the welding gun 10 downward.

When the welding gun 10 is tilted, for example, when the welding site of the workpiece 17 is vertical as shown in FIG. 2, the welding gun 10 is horizontal. When the attitude of the welding gun 10 is inclined in this manner, the cylinder pressure adjusting device 3 is operated by the operation of the attitude detector 2.
Controls the timing of switching the supply / exhaust of the switching valve 5,
The switching by the switching valve 5 is maintained in the air supply direction until the welding is completed, and the pressure adjusting valve 4 is controlled in accordance with the attitude angle detection signal from the attitude detector 2 to supply the air pressure to the ecological cylinder 24. Adjust. Welding gun 1
When the posture of 0 is inclined more than the limit, the weight of the welding gun 10 does not act on the coil springs 22 and 22, the balance is lost, and when the movable electrode 14 and the fixed electrode 13 clamp the workpiece 17, Although the difference between the center position of the clamp and the welding position cannot be absorbed by the eco-raising device 1, the pressure on the eco-raising cylinder 24 is adjusted to urge the bracket 20a as shown in FIG. 2 (b). The balance between the welding gun 10 and the coil springs 22 and 22 can be maintained by reducing the spring pressure of the coil springs 22 and 22 by the amount of reduction in the weight load of the welding gun 10. Therefore, by controlling the pressure of the air supplied to the eco-rising cylinder 24 in accordance with the inclination angle of the welding gun 10, the balance between the coil springs 22, 22 and the weight of the welding gun 10 is maintained, and the welding gun 10 is kept in balance. The function of preventing displacement of the workpiece 17 by the eco-rising device 1 is executed regardless of the posture change.

[0008]

As described above, the attitude detector provided in the welding gun detects the tilted attitude of the welding gun, and the cylinder pressure adjusting device controls the pressure adjusting valve to change the supply pressure to the ecological cylinder. Then, the welding gun is biased in the advancing direction of the movable electrode by the biasing force according to the attitude angle of the welding gun. As a result, the unbalanced balance between the weight of the welding gun due to the inclination of the welding gun and the spring pressure of the eco-raising device that balances the weight of the welding gun can be reduced by the biasing force of the eco-raising cylinder. And restore balance. By this action, the eco-rising device operates normally regardless of the position of the welding gun, and the deformation of the workpiece is prevented. Therefore, according to the present invention, it is possible to provide a spot welding gun in which the eco-izing device normally functions even at a welding position where the clamping direction of the electrode deviates from the vertical direction to the horizontal direction.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a spot welding gun including an eco-rising device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram illustrating an operation of the eco-rising device when the attitude of the spot welding gun shown in FIG. 1 is changed.

FIG. 3 is a configuration diagram of a spot welding gun including a conventional eco-rising device.

FIG. 4 is a configuration diagram of the spot welding gun shown in FIG. 3 when clamped.

FIG. 5 is a configuration diagram illustrating an operation of the eco-rising device when the attitude of the spot welding gun shown in FIG. 3 is changed.

[Explanation of symbols]

1 ... Equalizing device 2 ... Attitude detector (attitude detection means) 3 ... Cylinder pressure adjusting device (cylinder pressure control device) 4 ... Pressure adjusting valve (cylinder pressure control device) 10 ... Spot welding gun 13 ... Fixed electrode 14 ... Movable Electrode 15 ... Air cylinder (cylinder) 17 ... Workpiece 24 ... Equalizing cylinder

Claims (1)

[Claims] 1. A spot welding gun including a cylinder for moving a movable electrode forward and backward with respect to a fixed electrode disposed at a position facing the movable electrode, and a spot welding gun including the movable electrode and the fixed electrode are movable in the forward and backward directions of the movable electrode. At the position of detecting the tilted position of the spot welding gun, the spot welding gun is equipped with an eco-raising cylinder for urging the spot welding gun in the axial direction of each electrode. Means, and cylinder pressure control means for controlling the urging force of the ecological cylinder according to the detection signal of the attitude detection means.