JPH0144432B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic welding line feeding device that enables automatic feeding control such that the welding line of an object to be welded always matches the electrode pressurizing position.

Conventionally, automatic welding line feeding devices for seam welding machines use, for example, a link mechanism with a plurality of rotatable joints to move the welding object in a rotating manner under mechanical cam tracing control using electrode driving force. However, those that guide the weld line between the seam electrodes are widely used.

This type of conventional copying device does not have much problem when applied to so-called high-mix, low-mix, high-volume production where there is little change in the shape or size of the welded object, but recently, it is used in high-mix, low-volume production where model changes are severe. As time progressed, the capabilities of this type of conventional equipment limited its range of applications and were unable to adequately respond to today's increasingly high-speed production lines and mixed-flow production systems. In order to expand the scope of application in recent mixed flow production systems, conventional cam copying devices have the following problems.

(1) It is uneconomical to have to manufacture a cam device each time depending on the type of complicated object to be welded, which requires a large amount of manufacturing cost.

(2) It takes a lot of time and effort to replace the cam device.

(3) The entire device has a complicated structural design, and the position adjustment of the cam device is difficult and cumbersome.

As described above, various problems have been posed with conventional devices, and to date, it has not been possible at all to realize automation of an automatic feed device that is versatile enough to weld workpieces with complex shapes.

In view of the above-mentioned actual situation, the present invention adopts methods such as teaching playback control or numerical control for welding lines of various welding objects, which can be applied to a high-mix, low-volume production system. To provide an automatic welding line feeding device that has been made possible.

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

FIG. 1 is an example of a polar coordinate system in which a link device with multiple joints is applied.

1 is the welding machine body, 2 and 3 are the upper and lower seam electrodes,
Reference numeral 4 denotes a cradle that supports the welding object W on the front surface of the electrode, 5 a linkage device for horizontally rotating this cradle, and a first arm 6 and a second arm 7 rotate by joints 8 and 9. They are movably connected, and the pedestal 4 is mounted so as to rotate 360° about a support shaft 17 that vertically passes through the housing 10 of the second arm 7. Reference numerals 11, 12, and 13 indicate transmission gears (or sprockets). The first gear 11 of each gear is fixed to a fixed shaft 15 at the rear end of the first arm, which is rotatably supported by a support member 14 fixed to the welding machine main body side. The second gear 12 is fixed to a fixed shaft 16 at the rear end of the second arm, which is rotatably supported by the front end of the first arm. Further, the third gear 13 is fixed to the support shaft 17 rotatably supported at the tip of the second arm.

Reference numerals 18, 19, and 20 indicate motors of the drive power device. Of each motor, the first motor 18 is mounted on the welding machine body, the second motor 19 is mounted on the side of the first arm, and the third
The motors are respectively attached to the sides of the second arm, and the sprockets 21 of each motor and each gear 11, 12, 13 are connected by a chain or the like 22 so as to transmit the rotational driving force of each drive source to each arm. It is composed of

Based on this configuration, the upper and lower seam electrodes 2,
Each drive power device 18, 19, 20 is electrically controlled so that the rotation speed of No. 3 coincides with the feed speed and direction of the weld line.

In this case, the electrical control method is, for example, in the case of the playback method, the welding object is driven within the same plane by rotating the seam electrode during teaching, and manual operation is performed to prevent the electrode from deviating from the welding line. The link device is operated to simultaneously sample the weld line position of the object to be welded and the position data of each axis of the link device, that is, the rotation angle, and the data is stored in the electrical storage means.

Then, during automatic operation, the above position data is retrieved, and when the data almost matches the current value data of the welding line being fed, the position data of the link device stored at the same time as the position data at the time of teaching is retrieved. The difference between that data and the position data of the link device at the current position is calculated, the output is amplified by an amplifier, the drive source is operated by this output, and each axis of the link device is amplified. 15, 16, and 17 are rotated to control the attitude direction of the object to be welded and the positioning of the weld line.

By controlling as described above, it is possible to always accurately move the welding line to the electrode pressurizing position. In the case of numerical control, the welding line is controlled by inputting the necessary coordinate values and speed values for each axis that match the shape of the workpiece.

FIG. 2 shows another embodiment of the present invention applied to a Cartesian coordinate type robot system.

In this case, the pedestal 2 that supports the welding object W
3 is mounted on the first truck 24 so as to be rotatable around a support shaft 25, and a gear 26 attached to the circumference of the shaft 25 and the first truck 2
4 is engaged with a gear 28 of a drive power device 27 fixed to the drive power device 27, and is configured to rotate 360° by the driving force of the drive power device 27. The first truck 24
Two shafts 30 and 31 fixed to a trolley 29
It is slidably supported by, and moves forward and backward in the Y-axis direction by the driving force of the drive power device 32 using the feed screw 33 as a transmission body.

On the other hand, the second truck 29 is slidably supported by two shafts 35 and 36 mounted on the base 34, and is driven by the driving force of the drive power device 37 to drive the X-axis using the feed screw 33 as a transmission body. It is designed to be able to give forward and backward motion in the direction.

In such a device, each drive source 27, 3
2, 37 by the teaching playback method, for example, the position of each carriage 24, 29 and the support shaft 25 to correct and ensure the feeding position of the welding object and the position so as not to deviate from the welding line.
The rotation angle of is simultaneously memorized by the sampling means during teaching, and during automatic operation, the welding line feeding position of the welding workpiece is used as the main, and the position or rotation angle of each control axis is secondary, and the welding line feeding position of the welding workpiece is memorized. is detected, and the position of each control axis corresponding to this position is controlled.

In the case of this embodiment, the motor 37 only supplements the workpiece driving force by the electrodes, so the same effect can be obtained even if an air cylinder is used as the motor.

Therefore, the same operation as in the embodiment shown in FIG. 1 is repeated, and the welding locus can always be accurately moved to the electrode pressurizing position.

In this way, by adopting a control system that combines orthogonal coordinates and polar coordinates, it is possible to efficiently guide the welding line. In the case of numerical control, the necessary welding line control can be performed using data input using the link mechanism method described above.

As described above, according to the present invention, not only is it possible to always match the welding line of the welding object with the processing position and at the same time perform movement matching the welding speed, but also there is no need for the complicated cam copying device used conventionally. Even when welding objects with a wide variety of complex shapes, if the data necessary for teaching or numerical control is input each time the shape of the weld line changes, the same operation can be repeated automatically according to the program, so today In particular, in the field of seam welding, the conventional cam copying device has been replaced by an unprecedentedly versatile automatic feed control system that can be fully applied to mixed flow and high-speed automation production systems such as the above. The device can be realized and the scope of application can be expanded.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a polar coordinate type automatic feeder according to the present invention. FIG. 2 is a perspective view showing an automatic feeding device using a combination of polar coordinates and orthogonal coordinates. (Explanation of symbols), 4, 23...cradle, 10,
25...Support shaft, 5...Link device, 18,1
9, 20, 27, 32, 37... drive power device,
24...first trolley, 29...second trolley.

Claims (1)

[Scope of Claims] 1. A welding device comprising a pedestal for supporting the welding object in front of the interelectrode welding pressurizing position, and a link device consisting of a rotatable arm that rotatably supports the support shaft of the pedestal. , the pedestal and the link device are adapted to support rotational motion acting in the horizontal direction by a drive power device, and the drive power device is capable of welding the welding object by teaching playback control or numerical control. An automatic welding line feeding device characterized in that it is driven to align the line with an electrode pressurizing position. 2 It has a pedestal that supports the object to be welded in front of the inter-electrode pressurizing position, and a cart that rotatably supports the support shaft of this pedestal and is movable in several axes. This is an automatic welding wire feeding device that can provide rotational motion and linear motion by a drive power device, and the drive power device has a control method to align the welding line of the object to be welded with the electrode pressurizing position. An automatic welding wire feeding device characterized in that it is driven by a twisting motion.