JPH0317595B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an automatic spot welding device that automatically performs spot welding by squeezing a workpiece between a fixed side electrode and a sliding side electrode.

(Prior Art) As a conventional automatic spot welding device, for example, a device as described in Japanese Utility Model Application Laid-Open No. 60-131282 is known.

This conventional device has two spot electrodes facing each other that weld objects to be welded from both sides under pressure, one arm that supports these electrodes, and this arm that elastically moves in the direction of applying pressure to the spot electrodes. In an automatic spot welding apparatus, the automatic spot welding apparatus comprises a support means for the arm including a slide means for making the arm slidable, and a moving means connected to the supporting means and movable by itself, wherein the sliding means is connected to the moving means. It therefore had locking means such that sliding of the arm was impossible while the device was in motion.

Therefore, if the relative position of the object to be welded and the spot electrode deviates from the normal position in the sliding direction of the spot electrode, the arm will slide by the sliding means after the sliding side of the spot electrode contacts the object to be welded. By doing so, it is possible to absorb the positional deviation, and it is possible to prevent excessive impact from being applied to the workpiece from the spot electrode.Also, while the arm is moving, the elasticity of the support means prevents the arm from moving. The arm could be fixed with a locking means to prevent it from vibrating.

(Problem to be Solved by the Invention) However, in such conventional automatic spot welding equipment, it is difficult to absorb the relative deviation in the contact angle of the fixed side and sliding side electrodes to the workpiece. Because they did not have the means to do so, the following problems arose.

○B If both electrodes do not contact the workpiece at right angles, the distance between the electrodes with the workpiece sandwiched between them during welding will be farther than in the normal case where they contact at right angles, resulting in welding. The strength will become weaker.

○B When the workpiece has many inclined surfaces, the teaching time is reduced because the teaching must be done accurately and carefully so that both electrodes contact the workpiece at right angles at each welding point. It takes a lot of time and reduces productivity.

(Means for Solving the Problems) The present invention solves the above-mentioned problems and makes it possible to absorb deviations in the contact angles between the electrodes on the fixed side and the sliding side and the workpiece to be welded. It is an object of the present invention to provide an automatic spot welding device, and in order to achieve this object, a fixed side electrode and a sliding side electrode that weld the workpiece by sandwiching it from both sides are provided facing each other. , an automatic spot welding apparatus in which a slide support means capable of elastically sliding in the sliding direction of the slide side electrode is provided on the welding apparatus main body, and an arm supporting both the electrodes is supported by the slide support means; and the welding device main body, there is a rotation axis whose axis is orthogonal to the sliding direction of the sliding side electrode,
and rotation support means for elastically and rotatably supporting the arm, and the stationary electrode has a contact surface that is perpendicular to the sliding direction of the sliding electrode, and The contact surface is formed with a predetermined width of rotation in the tangential direction of rotation about the rotation axis.

(Function) Therefore, in the automatic spot welding device of the present invention,
By using the above-mentioned means, the relative angle between the contact sliding direction of both the fixed side electrode and the sliding side electrode and the welding surface of the workpiece is not a right angle, but the rotation of the contact surface of the fixed side electrode is not a right angle. If it is inclined with respect to the direction of the dynamic application width, the following operation is performed.

When both electrodes are slid in the contact direction, the welding surface of the workpiece is inclined, so the contact surface of the stationary electrode does not come into surface contact with the workpiece, and the rotation is applied in the width direction. Only one end is in contact.

While the slide side electrode is arranged on the axis of the rotation axis of the rotation support means, this contact surface has a rotation imparting width in the tangential direction of rotation around the rotation axis. Therefore, the direction of pressure applied at one end of the contact surface that contacts the workpiece is different from the normal direction to the rotation axis, and a moment is generated around the rotation axis, and this moment causes the arm to move. Rotate.

The rotation of this arm is such that the reaction force generated at one end of the rotation imparting direction of the contact surface matches the normal line of the rotation axis, and the contact surface is rotated at the position where this reaction force matches the normal line. The surface is in contact with the object to be welded, and the sliding side electrode is in normal contact with the object at right angles.

If the rotation of the arm gains momentum and exceeds the above normal state, only the end of the contact surface on the opposite side will come into contact with the workpiece, and a moment will be generated in the opposite direction. It is rotated in the opposite direction so that it is in the normal state.

(Example) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

First, the structure of an embodiment of the present invention will be explained.

The automatic spot welding apparatus according to the embodiment of the present invention includes a welding apparatus main body 10, a sliding side electrode 20, a fixed side electrode 30, an arm 40, a sliding support means 50, and a rotation support means 60.

The main body 10 of the apparatus is a part generally called a robot, and is used to move both the electrodes 20 and 30 to predetermined taught positions.

Further, a mounting board 11 is provided at the tip of the device main body 10. And this mounting board 1
1, as shown in FIGS. 1 and 2, four spring mounting plates 12 are erected at left and right upper and lower positions.

The slide side electrode 20 and the fixed side electrode 30 are used to weld a workpiece (workpiece) W, and are supported by the arm 40 so as to face each other.

Further, the slide side electrode 20 is provided so as to be slidable on the slide shaft d by an air cylinder 21, and has a rounded tip as shown in the figure.

The fixed side electrode 30 is fixedly provided on the arm 40, and has a contact surface 31 formed opposite to the slide side electrode 20. This contact surface 31
is formed perpendicularly to the slide axis d of the slide side electrode 20, and as shown in FIG.
It is formed wide in the horizontal direction (in the left-right direction in the figure), and this width is called the rotation imparting width b.

Note that both ends of the contact surface 31 in the direction of the rotation imparting width b are rounded.

As shown in FIG. 1, the arm 40 is approximately C.
The arm base portion 41 is formed on the side of the main body 10 of the device.

The slide support means 50 and the rotation support means 60
and the device main body 10 and the arm 40, respectively.
is interposed between the arm 40 and the device main body 1.
0, and a slide support means 5 is provided on the arm 40 side.
0 is provided, and a rotation support means 60 is provided on the device main body 10 side.

The slide support means 50 is provided between the rotation support body 61 attached to the apparatus main body 10 and the arm base part 41, and the slide support means 50 is provided above and below the arm base part 41. Slide rod 5 provided parallel to slide axis d
1, 51, and a rotating support 6 to support the slide rods 51, 51 in a slidably inserted state.
1, and coil springs 53, 53 interposed between the arm base portion 41 and the rotation support body 61 at the outer periphery of the slide rods 51, 51. The arm 40 is supported at a neutral position of the elastic force of the coil springs 53, 53.

The rotation support means 60 rotatably supports the arm 40 and performs rotation correction so that the contact angle between the electrodes 20, 30 and the workpiece W is always at right angles. 60 is the rotation support body 6
1. Rotation shaft 62, float support spring 63,
63, 63, 63 and rotation guides 64, 64.

The rotation shaft 62, as shown in FIGS. 1 and 2,
fixed to the mounting substrate 11 so that its axis c is perpendicular to the slide axis d of the slide side electrode 20 and the slide axis e of the slide support means 50;
The rotation support body 61 is rotatably supported by the apparatus main body 10.

As shown in FIG. 2, the rotating support 61 is
Four float support springs 63, 6 are provided between the spring mounting plates 12, 12, 12, 12.
3, 63, 63 are provided, and this rotation support 61
The elastic forces of the float support springs 63, 63, 63, 63 are balanced at a position where the center line of the slide axis d of the slide side electrode 20 overlaps.

Further, as shown in FIG. 2, the rotation support body 61 is provided with rotation guide elongated holes 65, 65 for allowing vertical rotation by a predetermined amount and for smooth rotation. This rotation guide elongated hole 6 is formed.
The rotation guides 64, 64 are inserted through the rotation guides 5, 65.

In addition, 70 in the figure is a pressure receiver, which is provided on a jig that supports a workpiece W (not shown), and which is attached to the fixed side electrode 3.
This is to prevent the workpiece W from being scratched when pressurized by zero.

Next, the operation of the embodiment will be explained.

First, the welding point on the workpiece W is taught, and at this time, the tip of the slide-side electrode 20 is taught to come into contact with the workpiece W at a point on the axis c of the rotating shaft 62 during welding.

Next, during welding, the arm 40 is first moved by the operation of the apparatus main body 10 so that the welding point of the workpiece W is placed at an intermediate position between the electrodes 20 and 30, as shown in FIG.

At this time, the positional relationship between the workpiece W and both electrodes 20 and 30 is such that the workpiece W is inclined with respect to the rotation imparting width b of the contact surface 31 of the fixed side electrode 30, as shown in FIG. If so, it operates as described below.

The air cylinder 21 is driven and the slide side electrode 2
0 to the workpiece W side. Then, when the slide side electrode 20 comes into contact with the workpiece W (Fig. 3),
The arm 40 is slid upward in the drawing by the slide support means 50 due to the reaction force from the workpiece W against the pressing force, and the fixed side electrode 30 comes into contact with the workpiece W.

However, due to the tilt of the workpiece W, the fixed electrode 3
The contact surface 31 of No. 0 does not come into surface contact, and only one end side comes into contact. And still the slide side electrode 20
When a pressure is applied to the fixed side electrode 30, the fourth
As shown in the figure, a reaction force F is received from the workpiece W, and since the direction of this reaction force F is not parallel to the normal f to the axis c of the rotation shaft 62, the moment M about the rotation shaft 62 is This moment M causes the arm 40 to rotate, and as shown in FIG. Then, a normal contact state is achieved.

Thereafter, a current is passed between the electrodes 20 and 30 to perform welding.

In this way, in the automatic spot welding apparatus of the embodiment, even if the workpiece W is inclined in the direction of the relative rotation width b with respect to both electrodes 20 and 30, the rotation axis 62
Since the electrodes 20 and 30 can be rotated around the center of
This reduces the need to consider the angle of contact, and allows teaching to be performed in a short time.

Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and the present invention may be modified without departing from the gist of the present invention. included.

For example, in the embodiment, the positional relationship between the slide means and the rotation means is such that the slide means is on the device main body side,
Although the rotation means is disposed on the arm side, the rotation means may be placed in the opposite positional relationship.

Furthermore, in the embodiment, a spring is shown as a member that provides elasticity to the sliding means and the rotating means, but it may also be a magnet, soft rubber, or the like, for example.

(Effects of the Invention) As explained above, in the automatic spot welding apparatus of the present invention, there is a difference in the contact angle between the fixed side electrode and the sliding side electrode between the workpiece contact sliding direction and the workpiece to be welded. This allows both electrodes to be in contact with the workpiece at right angles at all times.
The effect is that the welding strength is not weakened due to deviation of this contact angle, and quality can be improved.

Furthermore, this basic effect reduces the need for both electrodes to contact the welding surface at right angles when indicating the number of welding points of the welding device, resulting in the effect of shortening the teaching time.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an automatic spot welding apparatus according to an embodiment of the present invention, FIG. 2 is a sectional view showing essential parts of the apparatus according to the embodiment, and FIGS. 3 to 5 are views showing the operation of the embodiment. 10...Device main body, 20...Slide side electrode,
30... Fixed side electrode, 31... Contact surface, 40...
Arm, 50...Slide support mechanism, 60...Rotation support mechanism, W...Work (object to be welded), b...
Rotation width.

Claims (1)

[Scope of Claims] 1. A slide support means that is provided with a fixed side electrode and a sliding side electrode facing each other for welding the object to be welded by sandwiching the object from both sides, and that is elastically slidable in the sliding direction of the sliding side electrode. is provided in the welding device main body, and an arm for supporting both electrodes is supported by the slide support means, wherein an arm is provided between the arm and the welding device main body with respect to the sliding direction of the slide side electrode. Rotation support means having a rotation axis whose axis is perpendicular to each other and elastically rotatably supports the arm is provided, and the fixed side electrode is rotated relative to the sliding direction of the sliding side electrode. It has a contact surface that is a right-angled surface, and the contact surface is formed to have a rotation imparting width of a predetermined dimension in a tangential direction of rotation about the rotation axis. Automatic spot welding equipment.