JPH0755377B2 - Welding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to one mounting frame, for example, a wrist of a robot, to which two or more welding guns which are operated at the same time are mounted. The present invention relates to a welding device capable of significantly increasing work efficiency.

(Prior Art) For example, when joining a sill inner and a sill outer of a side sill by spot welding in an automobile body assembly line, since there are a considerable number of predetermined welded parts on the work, the welding work For the purpose of increasing work efficiency, a welding apparatus as illustrated in FIG. 4 has been generally used conventionally.

This device is equipped with a robot wrist 1 as a mounting frame.
, And attach the two welding guns 2 and 3 by positioning them at predetermined relative positions.
In addition, two welding transformers 5 and 6 controlled by one weld timer 4 are connected in parallel to each other, and respective pressurizing cylinders 2a for pressing the electrode tips of the respective welding guns 2 and 3 onto the work. , 3a are connected to a control device 8 by a common pressurizing signal supply system 7.

In such a welding apparatus, both welding guns 2 and 3 are simultaneously operated with the same welding current under the action of one weld timer 4 and one pressurizing signal supply system 7, and the welding of the side sill is performed. Work can be performed efficiently.

(Problems to be Solved by the Invention) By the way, in such a conventional technique, both welding guns are used.
Welding current and energizing time of 2 and 3 are equal, and
Since both pressurizing cylinders 2a and 3a are always operated at the same pressure at the same time, when the adaptive welding conditions of the respective welding parts of the respective welding guns 2 and 3 are different from each other, for example,
If it is necessary to weld two overlapping parts of a plate-shaped work with one welding gun and three overlapping parts with the other welding gun, it is necessary to perform optimal welding on both parts. In addition to the problem that it is not possible, there was a problem that the welding pitches of both welding guns 2 and 3 could not be different from each other.

Moreover, in this conventional technique, since the welding guns 2 and 3 cannot be displaced relative to the wrist 1 in any direction, the welding line shapes required for both welding guns 2 and 3 are different from each other. In this case, for example, when it becomes necessary to retract one of the welding guns 2 and 3 to a position where it does not interfere with the work, the relative displacement of one welding gun with respect to the work is
When it becomes necessary to make the welding gun larger or smaller than that of the other welding gun, there is a problem that it is impossible to perform welding on a desired portion of the work.

The present invention advantageously solves the above problems of the prior art. Even when the adaptive welding conditions of the respective welding parts by a plurality of welding guns are different from each other, optimum welding is always performed on each part. In addition, the welding pitch of each welding gun can be appropriately changed as required, and further, even when the required welding line shape of each welding gun is different from each other, it effectively corresponds. A welding device capable of performing the above is provided.

(Means for Solving the Problems) In the device of the present invention, a plurality of welding guns are attached to one attachment frame so that they can be displaced relative to the welding gun, and
Provided are respective drive means for displacing the welding guns relative to the mounting frame in a one-dimensional direction, more preferably in a two-dimensional direction, to at least bring the welding guns toward and away from the work piece. , And each of these driving means and the pressurizing cylinder of each welding gun, independently of each other,
And the respective pressurizing cylinders are connected to the control device by respective actuating signal supply systems and pressurizing signal supply systems for supplying independent actuating signals to each other, and further, the respective welding guns are also independent from each other. The welding guns are connected to the control device by respective welding current supply systems that supply independent current signals.

(Operation) According to the present invention, for example, when welding is performed by respective welding guns on respective welded portions having different adaptive welding conditions, the operation of the pressurizing signal supply system independent from each other is performed. Below, the work pressure and pressurization time of each welding gun are individually controlled, and the welding current supply system that is independent of each other is used to control the current value and energization time of each welding gun. An electric current can be supplied, which makes it possible to simultaneously perform the desired and excellent welding processing on each part of the work.

Here, when the adaptive welding conditions of the respective welded parts are the same, the welding current of the same condition is supplied to all the welding guns, and the respective pressurizing cylinders are simultaneously operated at the same pressure. In particular, all parts can be welded uniformly.

Further, for example, when the welding pitch of at least one welding gun is changed from that of another welding gun, the welding current supply system and the pressurization signal supply system for the other welding gun are activated when the other welding gun is operated. While keeping both of them in the inactive state, by operating only that welding gun at the required position, the welding pitch of other welding guns can be changed as required without affecting the welding pitch. Easy to do.

Further, when welding line shapes required for a plurality of welding guns are different from each other, for example, when welding to a unique portion by one welding gun, other welding guns are evacuated to a position where they do not interfere with the work. For driving the welding gun, the welding gun is actuated based on a signal from the actuation signal supply system to displace the welding gun relative to the mounting frame in one-dimensional or two-dimensional directions. The gun can be sufficiently separated from the work.
Therefore, while the other welding gun is in the retracted state, while keeping that gun inactive, by operating one welding gun at the required position, the intended welding to the unique portion can be made extremely smooth. It can be carried out.

Thus, here, each welding gun can be individually displaced into the required operating position and retracted position under the action of the mutually independent actuating signal supply system, and the mutually independent pressurizing signal is applied. Under the action of the supply system, it is possible to individually control the work force and work pressurization time of each welding gun, as well as the required resting time, and further, welding independent of each other. With the current supply system, in addition to stopping the current supply to each welding gun as required, it is possible to individually control the current value of the supply current and the energization time.
By smoothly and swiftly responding to changes in welding pitch, mutual differences in welding line shapes, etc., it is possible to always carry out welding exactly as intended.

(Example) Hereinafter, the present invention will be described based on illustrated examples.

FIG. 1 is a signal system diagram illustrating the device of the present invention.
Reference numeral 11 denotes a mounting frame which can be a wrist of a robot, and 12 and 13 respectively denote two welding guns mounted on one mounting frame 11 so as to be capable of relative displacement.

Both of the welding guns 12 and 13 here are mounted so as to be swingable in a plane including the paper surface around the fulcrum, but they can be swung in a plane perpendicular to the paper surface. In addition to the swinging motion, the mounting frame 11 can be moved back and forth.

And here, both welding guns 12, 13 are attached to the mounting frame 11
In order to make an oscillating movement with respect to the mounting frame 11, the mounting frame 11 is provided with cylinders 14 and 15 as an example of driving means, and the respective piston rods of these cylinders 14 and 15 are
Connected to the rear ends of the welding guns 12 and 13, respectively. Here, these cylinders 14 and 15 may be replaced with servo cylinders, motors, etc., which also can bring about the desired rocking movement of the welding guns 12 and 13.

Further, in the figure, 16 and 17 are the electrode tips 12a and 12 of the welding guns 12 and 13, respectively.
The respective pressurizing cylinders for pressing a and 13a, 13a against the work are shown.

FIG. 2 shows the welding guns 12, 1 mounted in this way.
It is a diagram showing an application example of 3, the welding gun 12, 13 of this example,
By attaching them to the wrist of a robot 18 capable of traveling in a direction perpendicular to the plane of the drawing, on a transfer device 19 capable of traveling in the pitch, with respect to an automobile body 21 positioned and mounted via a fixture 20. , Which provides a welded joint between the sill inner and the sill outer of the side sill 22,
The welding guns 12 and 13 used for such an application are based on the fact that their required welding line shapes are different from each other, and one of them is placed below the side sill 22,
When it is necessary to lower it to a position where it does not interfere with it, it is mounted on the mounting frame 11 as shown in an enlarged view in FIG. 2 (b).

That is, here, as illustrated for one of the welding guns 12, the mounting frame 11 having a rectangular cross-sectional shape.
While mounting the bracket 23 on the rear surface side, the cylinder 14 pivotally supported on the upper portion of the bracket 23 is connected to the upper end portion of the lever 24 pivotally supporting the middle portion of the bracket 23,
The lever 24 is connected to the rear end of the welding gun mounting lever 26 via an intermediate link 25 connected to the lower end of the lever 24, while the intermediate portion of the welding gun mounting lever 26 is pivotally supported on the mounting frame 11. The welding gun 12 is attached to the lower surface of the tip portion thereof through the eco-rising mechanism 27. The welding guns 12 and 13 thus mounted are respectively attached to the welding gun mounting levers by retracting the piston rod of the cylinder 14 and rotating the lever 24 in the clockwise direction in the figure.
It is possible to rotate around the fulcrum of 26 and descend for a sufficient distance from the working position shown by the solid line in the figure to the non-working position shown by the virtual line.

And according to the present invention, each of the cylinders 1 capable of relatively displacing the welding guns 12 and 13 as described above.
4, 15 are connected to the control device 30 by separate actuating signal supply systems 28, 29, respectively, as shown in FIG. 1, and additionally the pressurizing cylinders 16, 17 of the respective welding guns 12, 13 are also connected. Further, they are connected to the control device 30 by pressure signal supply systems 31 and 32 which are independent of each other.

Therefore, here, the respective welding guns 12 and 13 can be independently displaced relative to the mounting frame 11 based on the signal from the control device 30, and the welding guns 12 and 13 are used for pressurization. The cylinders 16 and 17 can independently pressurize the work.

Furthermore, here, the respective welding guns 12 and 13 are respectively connected to the control device 30 by welding current supply systems 33 and 34 which are independent of each other, and in the respective welding current supply systems,
Weld timer 33a, 34a and welding transformer 33b, 34b,
By interposing them in series from the control device side, it is possible to supply welding currents having different current values, energization times, etc. to the respective welding guns 12, 13.

A series of operating steps of the respective welding guns 12 and 13 when the welding apparatus configured as described above is applied to welding of the side sill 22 as shown in FIG. 2 will be described below with reference to FIG. To do.

In the figure, among the first to 28th steps of the respective welding guns 12 and 13, the black coating step indicates the step where the welding gun performs welding processing, and the white step indicates the step where welding processing is not performed. Show.

Here, first, the mounting frame 11 located in parallel with the side sill 22 is moved in parallel in the X-axis direction of the three-dimensional coordinate system so that both welding guns 12 and 13 are located near the side sill 22. The guns 12 and 13 are brought to the first step position, and the guns 12 and 13 are brought to the second step position by the subsequent movement of the mounting frame 11 in the Z-axis direction. And after that, each welding gun 12,13
Are sequentially moved to the 21st step position at equal pitches, and each welding gun is operated only at the required step position.

That is, in this example, when the right half of the figure is welded by the welding gun 12 and the left half of the figure is welded by the welding gun 13, one welding gun 12 is used for the second, third, and second steps. When located in steps 12, 13th, 16th and 20th, neither the pressurizing signal nor the welding current is supplied thereto, and the other welding gun 13 is the sixth step, the eleventh step, the seventeenth step. When located in step and 21st step, supply of the pressurizing signal and welding current thereto is stopped. Therefore, here, the respective welding guns 12 and 13 perform welding processing at a welding pitch as required.

After moving the welding guns 12 and 13 in the Y-axis direction of the three-dimensional coordinate system to the 21st step position in this way,
For the purpose of smoothly performing the welding in the 23rd and 24th step positions, the one welding gun 12 is operated by operating the cylinder 14 by the action of the one operation signal supply system 28.
Is relatively displaced downward until it does not interfere with the side sill 22. At this time, the other welding gun 13 remains at the 21st step position, and thereafter, welding is sequentially performed at the 23rd and 24th step positions based on the movement of the mounting frame 11.

A welding gun that completes a series of welding operations as described above 1
2 and 13 reach the 25th step position separated from the side sill 22 by the displacement of the mounting frame 11 in the Z-axis direction, and reach the 26th step position by the subsequent displacement in the X-axis direction.

Finally, in order to wait for a series of subsequent welding operations by both welding guns 12 and 13, the welding gun 12 displaced relative to the mounting frame 11 is returned to its original position based on the re-actuation of the cylinder 14. Let and those welding guns
12, 13 are returned to the 28th step position by moving the mounting frame 11 in the Y-axis direction.

Therefore, here, the welding current supply systems 33, 34, the pressurization signal supply systems 31, 32, and the operation signal supply systems 28, 29 for the respective welding guns 12, 13 are provided independently of each other. Therefore, it is possible to supply different welding currents to the respective welding guns 12 and 13, and of course, the welding pitches of the respective welding guns 12 and 13 can be appropriately different as required, and further, , Both welding guns 12,13
Even when the required welding line shapes of the above are different from each other, the desired welding can be sufficiently smoothly performed under the action of the cylinders 14 and 15.

The present invention has been described above based on the illustrated example, but it goes without saying that three or more welding guns can be attached to the attachment frame, and the device of the present invention can be applied to applications other than those shown in the drawings. is there.

Therefore, according to the present invention, in particular, the operation signal supply system, the pressurization signal supply system, and the welding current supply system are independently connected to the plurality of welding guns, and each of these is connected. By operating each of the supply systems independently,
Even if the adaptive welding conditions of the welding parts of multiple welding guns differ from each other, it is possible to always perform optimal welding at each welding part, and also to set the welding pitch of each of the multiple welding guns. It can be appropriately changed depending on the situation, and it is possible to sufficiently deal with the case where required welding line shapes of a plurality of welding guns are different from each other.

[Brief description of drawings]

 FIG. 1 is a signal system diagram illustrating the device of the present invention, FIG. 2 is a front view showing an application example of the device of the present invention, FIG. 3 is a diagram showing a series of operating steps of a plurality of welding guns, and FIG. It is a signal system diagram which shows a prior art example. 11 …… Mounting frame, 12,13 …… Welding gun 14,15 …… Cylinder, 16,17 …… Pressurizing cylinder 22 …… Side sill, 28,29 …… Actuation signal supply system 30 …… Control device, 31, 32 …… Pressure signal supply system 33,34 …… Welding current supply system 33a, 34a …… Weld timer 33b, 34b …… Welding transformer

Claims (1)

[Claims] Claim: What is claimed is: 1. A mounting frame (11), a plurality of welding guns (12, 13) mounted on the mounting frame so as to be displaceable relative to the mounting frame, and these welding guns with respect to the mounting frame. Respective driving means (14, 15) for relatively displacing to bring the welding gun to and away from the work piece, and these driving means and pressurizing cylinders (16, 15) of the respective welding guns. 17)
Are connected in parallel to each other and supply independent actuating signals from the respective control means to the respective driving means and to the respective pressurizing cylinders from each other, and respective actuating signal supply systems (28, 29) and adders. The pressure signal supply system (31, 32) and the respective welding current supply systems (33) which are independently connected to the respective welding guns and which supply independent current signals from the controller to the welding guns (33, 32). , 34) and welding equipment.