JPS5947631B2 - automatic welding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an automatic welding device, and more particularly to an automatic welding device equipped with a plurality of replaceable sensors for detecting the position of a weld line.

[Background of the invention]

Figure 1 is an external view showing an example of an automatic arc welding device using an industrial robot. 1 is a base, 2 is a column mounted on the base 1 so that it can move freely, and 3 is a column 2 that can be moved up and down and back and forth. A freely supported arm 4 is a welding torch held by a wrist 4 attached to the tip of the arm.

The column 2 and the arm 3 are respectively positioned in the transverse, longitudinal and vertical directions by X-axis, Y-axis and Z-axis positioning devices, respectively. Also, on wrist 4, swing in the horizontal direction!
) (SW axis) and vertical bending (BD axis). The position and orientation of the welding torch 5 are sequentially determined by each of these axes according to the given command values, and arc welding work is performed. FIG. 2 is a block diagram showing an example of the configuration of a control device that controls the operation of such an industrial robot. Reference numeral 21 denotes a storage device 22 for storing a series of position data for each axis in order to perform the above-mentioned arc welding work. The positioning device 2 performs an interpolation calculation on the manual command given by the operator or the position data read from the storage device 21.
3 is a processing device that outputs a position command, 23 is a processing device 22
25 is a position detection device that detects the position of each axis of the mechanism section 24, and the detected value is the position command input to the positioning device 23. The values are fed back and are also input to the processing device 22 as current position data for each axis. FIG. 3 shows the positional relationship between the welding torch and the workpiece when arc welding is performed using the automatic arc welding apparatus as described above. In FIG. 3, 31 and 32 are a pair of base metals, and a line 33 where both base metals touch is a welding line. As shown, the welding torch 5 with respect to the welding line 33 must be maintained at an optimal position at each moment of the welding operation in order to obtain a good quality weld. However, because the position data stored in the storage device 21 was inaccurate, the welding torch 5
The position of the welding line may shift to the 5" position indicated by the broken line, or the base metals 31 and 32 may shift to the 3V, 32" position indicated by the broken line due to dimensional errors or installation errors of the workpiece, and the weld line position may shift to the 33" position indicated by the broken line.
33" is a common occurrence in actual welding work, and for this reason, the storage device 21 is simply
Good welding quality cannot be obtained if the work is performed in accordance with the position data stored in the welding machine. Figure 4 shows a method proposed to improve the above points, and the welding torch 5
A sensor 6 is attached to the.

A pair of sensor elements 7 and 8 are attached to the sensor 6, and each sensor element 7, 8 is attached to the base material 31.
and outputs a voltage according to the distance to 32. By referring to this output voltage, the welding torch 5 is connected to the welding line 33.
It can be positioned at the optimal position. Utilizing this, before performing welding work, find the optimal position of the welding torch 5 with respect to the welding line 33, and after correcting the position data stored in the storage device 21 using the position data of each axis at this time, It is designed to perform welding work.
This makes it possible to eliminate the factors that degrade welding quality. FIG. 5 is a diagram illustrating the effective range of such a sensor, in which sensor elements 7 and 8 are mounted at a position a certain distance L away from weld line 33. This distance L is related to the length t and diameter d1 of the sensor elements 7 and 8 or the diameter D of the welding torch 5, and cannot be made too small. That is, such a sensor 6
In this method, the distance between the sensor elements 7, 8 and the base metals 31, 32 at a distance L from the welding line 33 is optimally selected, and the welding torch 5 is equivalently positioned at the optimal position with respect to the welding line 33. This is what I am trying to do. Therefore, in order to position the welding torch 5 at the optimal position using this sensor 6, the angles θ1 and θ2 between the base metals 31 and 32 and between the base metal 32 and the welding torch 5 must be adjusted respectively. It is necessary that the angles θ1 (e.g. 90°) and θ2 (e.g. 45°) exactly match the promised angles, and if these angles θ1, θ2 deviate from the specified angles θ1, θ2,
Even if the distance between the sensor elements 7 and 8 and the base metals 31 and 32 becomes optimal, the welding torch 5 is not at the optimal position with respect to the welding line 33. However, in reality, the welding distortion may be corrected or the posture of the welding torch 5 may not be correct.
These conditions are often not met;
Even if the sensor 6 is used, good welding quality may still not be ensured in some cases. In addition, in order to use this sensor 6,
The distance L between the welding line 33 and the sensor elements 7 and 8 is
It is necessary that the length is smaller than the length L'' of the base material 32 (or 31), but there are cases where this is not satisfied and the sensor 6 cannot be used at all.The factors that limit the applicable range of the sensor 6 are the weld line This is due to the large distance L between 33 and the sensor elements 7 and 8, and this distance L cannot be reduced as described above.Furthermore, this sensor 6 is intended for fillet welding. Therefore, it cannot be applied to other welding methods such as butt welding, lap welding, etc. Due to these factors, even if the sensor 6 is provided, the range in which welding can be performed using the sensor 6 in actual welding work is limited. This is sometimes limited to a small portion of the total length of the weld line, and is a major obstacle to ensuring quality when performing welding using automatic welding equipment.Furthermore, depending on the structure of the material to be welded, In some cases, the sensor 6 used for correcting the position data becomes an obstacle, and the desired welding cannot be carried out successfully.

In any case, the method shown in FIGS. 4 and 5 in which both the welding torch 5 and sensor 6 are placed side by side is not suitable for welding in a cramped place. [Object of the Invention] An object of the present invention is to provide an automatic welding method that eliminates the drawbacks of the prior art described above, dramatically expands the range of sensor application, and easily ensures good welding quality.

[Summary of the invention]

The features of the present invention include the welding torch, sensors of different shapes, an adapter provided at the tip of the arm for easily attaching and detaching the welding torch and the sensors, and a device for detaching and storing the welding torch and the plurality of sensors. 1. A welding device comprising: a support base having a holding means; and after checking a weld line with a sensor suitable for the shape of a material to be welded, a torch is attached in place of the sensor to perform welding.

[Embodiments of the invention]

Next, the present invention will be explained in detail with reference to the drawings showing examples.

FIG. 6 is a diagram showing an embodiment of the present invention, in which 3 is an arm of an industrial robot, 4 is a wrist, and 5 is a welding torch, which are the same components as the parts with the same reference numerals in FIG. Reference numeral 9 is a hydraulic motor attached to the wrist 4 that can drive two axes.

10 is the SW axis rotation center, 11 is the BD axis rotation center, 12 is a suction device with a built-in electromagnet, and 13 and 13' are suction device 1.
2 is an adapter for attaching the welding torch 5 and sensor 6 to the wrist 4; 14 is a support stand for holding the welding torch 5 or sensor 6 that is not in use; 15 is an adapter for attaching the welding torch 5 and the sensor 6 to the support stand 14; Like the suction device 12 for holding the sensor 5 or the sensor 6, it is a stationary suction device incorporating an electromagnet.

The support stand 14 is equipped with a plurality of fixed-side suction devices 15 in the depth direction of the paper so that the welding torch 5 and sensor 6 can be held at the same time. Figure (A) shows a situation in which a welding torch 5 is attached to the wrist 4 via an adapter 13 using a suction device 12 in order to perform welding work, and the figure (opening) shows a sensor for measuring the weld line position. 6 is attached to the wrist 4 by the suction device 12 via the adapter 13'. Before the work, the welding torch 5 and the sensor 6 are held on the support base 14 by the fixed suction device 15 of the support base 14 . In this state, each axis of the industrial robot is driven to position the wrist 4 at a position facing the support base 14, as shown in FIG. At this time, the suction device 12 faces the adapter 13 with an extremely small distance therebetween. In this state, when the electromagnet built in the fixed-side suction device 15 is de-energized and the electromagnet built in the wrist-side suction device 12 is excited, the adapter 13 and welding torch 5 are attached to the wrist by the suction device 12. Figure 1 is a partial view showing the detailed structure of the adapter 13, 13'.
6 is provided. Further, the sensor adapter 13' is provided with a connector 17 for deriving the output voltage of the sensor. Although not shown, the suction device 12 includes a protrusion 16
Hole and connector 1 that fit with ? A connector receiving portion is provided to electrically connect with the sensor and take out the sensor output voltage. The protrusion 16 is provided to regulate the mounting position of the adapters 13, 13' and to counteract the suction force of the suction device 12 and external force acting in a direction perpendicular to it. The protrusion 16 also prevents the adapters 13 and 13' from falling when the excitation of both the suction device 12 and the fixed side suction device 15 is cut off when replacing the welding torch 5 or sensor 6 shown in FIG. 6C. To prevent. In the above configuration, the relative position of the welding line position that would be detected by the sensor 6 when the sensor 6 is attached to the wrist 4 with respect to the suction device 12, and the tip of the welding torch 5 when the welding torch 5 is attached (strictly is the point that generates an arc)
so that the relative positions with respect to the adsorption device 12 are equal,
A welding torch 5 and a sensor 6 are attached to the adapters 13, 13'. If this condition is satisfied, a plurality of different types of sensors 6 can be prepared and used by replacing them as appropriate. FIG. 8 shows an example of different kinds of sensors prepared in this way. The sensor 61 shown in FIG. 1A is one in which the sensor elements T and 8 are mounted so as to cross each other, and the distance from the weld line position to the sensor elements 7 and 8 (corresponding to FIG. 5 L) is extremely small. Sensor 62 shown in
The sensor 63 shown in Figure C has the sensor elements T and 8 mounted in parallel so that it can be applied to butt welding. It's something I wanted to do. In the figure, the broken line hypothetically shows the workpiece to be welded. As is clear from the above explanation, since the welding torch and the sensor are installed separately in the automatic welding device and used by replacing them, the sensor elements T, 8
It is possible to reduce the distance between the welding line and the welding line, and it is possible to reduce the influence of angle errors between both base metals and welding torch posture errors on the welding torch tip position error during fillet welding. At the same time, the sensor can also be applied to small workpieces.

In addition, even if a single workpiece includes different types of welding such as fillet welding, butt welding, and lap welding, preparing multiple sensors that can be adapted to these various welding types can be used to find the optimal By selectively using sensors, it becomes possible to apply sensors, and the applicable range of sensors can be dramatically expanded compared to conventional methods, which also dramatically expands the applicable range of automatic arc welding equipment itself. In addition, it can have extremely large industrial effects, such as being able to maintain a high level of welding quality when welding is performed using automatic welding equipment. Furthermore, since the sensor and welding joint are replaced by positioning by driving each arm positioning axis, the work is efficient. Furthermore, since the sensor and welding torch are not placed side by side at the same time, welding can be performed in cramped places. Note that the object of the present invention can be achieved by using other methods such as a mechanical method or vacuum suction as a means for attaching the adapter 13 to the wrist, instead of using the above-mentioned electromagnetic method.

〔Effect of the invention〕

According to the present invention, it is possible to check the weld line using a sensor suitable for the structure of the material to be welded, so that accurate welding can be performed efficiently.

[Brief explanation of the drawing]

Fig. 1 is an external view showing an example of an automatic arc welding device using an industrial robot, Fig. 2 is a block diagram showing an example of the configuration of the control device of the device shown in Fig. 1, and Fig. 3 is an illustration of the welding torch and workpiece. 4 is a diagram showing a conventional device equipped with a sensor, FIG. 5 is a diagram showing a relationship between a sensor and a welding line, and FIGS. 6, 7, and 8 are diagrams showing the implementation of the present invention. It is a figure which shows an example. 1...Base, 2...Column, 3...
...Arm, 4...Wrist, 5...
Welding torch, 6...Sensor, 7, 8...
-Sensor element, 13, 13'...adapter, 14...support stand, 15...fixed side adsorption device, 21...storage device, 22...・・・・・・
・Processing device, 23...Positioning device, 24...
...Mechanism section, 25...--Position detection device.

Claims (1)

[Claims] 1. In an automatic welding machine equipped with a storage device that stores welding line data set in advance and an arm that is controlled based on the data in the storage device, a welding torch or a welding line sensor is attached to the tip of the arm. a welding torch with an adapter having an engaging part of the same structure that can be engaged with the engaging means, a plurality of welding line sensors, and the welding torch or the plurality of welding line sensors. A welding line suitable for the shape of a member to be welded, comprising the torch and a welding line sensor support device having a holding means for holding the adapter at a portion facing the engaging portion of the adapter when removed from the engaging means of the arm. An automatic welding device characterized by selecting a sensor and checking the welding line, and then performing welding with a torch.