JPS6384778A - Automatic welding equipment - Google Patents

Abstract

PURPOSE:To safely perform the welding work by inputting the error correction data outputted from an arithmetic unit and stopping a control action when one hand at least of the error correction data and an accumulated value of the error correction data exceeds a tolerance. CONSTITUTION:The error correction data P are inputted and these data are added to the previous correction data to calculate the accumulated value R of the error data. This accumulated value is compared with an allowable ceiling value and when the accumulated value exceeds the allowable ceiling value, an alarm signal is given to an alarm device 25 and the input of the error correction data to a numerical controller 13 is stopped to stop the welding. The welding can be performed safely by the equipment with this constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic welding device that performs control to align a welding torch with a reference position.

[Prior Art] As is well known, arc welding is performed by moving the welding torch along the welding line, but in order to obtain a good welding result, the aiming position of the welding torch during welding must be aligned with the welding line (standard). position). It is also necessary to maintain the vertical position of the welding torch (the distance between the torch and the workpiece) at a predetermined reference position during welding. Furthermore, in automatic welding equipment that automatically welds without performing torch tracing control after positioning the welding torch at a set welding start position, the torch is positioned at a predetermined welding start position (reference position) when welding starts. must match.

However, in general, it is unavoidable that variations occur in the machining accuracy of the workpiece, especially in the machining accuracy of the groove, and it is also unavoidable that variation occurs in the positioning viscosity of the workpiece. Therefore, it is unavoidable that the welding torch position deviates from the reference position. Therefore, in order to obtain good welding results, it is necessary to control the welding torch position to match the reference position at the start of welding (when performing welding start position control) or during welding (when performing torch position tracing control). need to be done.

For example, in consumable electrode arc welding in which welding is performed while the welding torch is oscillated in the width direction of the groove of the workpiece, the position of the welding line is used as the reference position, and welding is performed in the direction perpendicular to the welding line. It is necessary to control the torch position adjustment mechanism that adjusts the position so that the torch follows the welding line so that the oscillation center of the torch (the target position of the torch) is always aligned with the welding line. In addition, the vertical position of the welding torch is maintained at the reference position during welding by controlling the vertical and low ffl adjustment mechanism (1 to -chi) that adjusts the distance between the welding torch and the workpiece, which is placed above and below the welding torch. - In automatic welding equipment, these controls need to be performed automatically. Therefore, automatic welding equipment includes a torch position adjustment mechanism that adjusts the position of the welding torch (the position of the torch in the direction perpendicular to the welding line or the vertical position of the torch);
An error correction data calculation device that calculates the deviation of the welding torch from a reference position and calculates and outputs error correction data necessary for matching the welding torch position with the reference position as needed; and an error correction data calculation device that outputs the error correction data. A numerical control device is provided which controls the position of the welding torch to match the welding reference position by inputting the error correction data obtained by inputting the error correction data. Based on this, the electric method of the torch position adjustment mechanism is controlled to match the torch position with the reference position.

[Problems to be Solved by the Invention] As mentioned above, in automatic welding equipment, control is performed to automatically match the position of the welding torch with the reference position, but the controllable range is limited. Since there are inherent limitations, it is necessary to keep the processing accuracy and positioning accuracy of the workpiece within a predetermined range. For this reason, special consideration is given to the processing accuracy of the grooves of objects to be welded using automatic welding equipment, and the processing process is controlled to keep the processing viscosity within a predetermined range. ing.

Therefore, when welding objects to be welded, the data output from the error correction data separation device is distributed within a certain tolerance range, and as long as the processing process of the objects to be welded is properly controlled, Error correction data exceeding the allowable range should never occur.

However, in reality, due to an abnormality in the sensor installed in the automatic welding equipment or the intrusion of external noise, the error correction data given to the numerical control equipment may not be corrected even though the error is within the allowable range. The range may exceed the allowable range.

Furthermore, even if the dimensional viscosity of the workpiece is within the allowable range and there is no abnormality in the equipment, if there is a 1V positioning error of the workpiece,
The error correction data is not distributed within a certain range and has a discrete value of 1.
If welding continues in such a case, good welding results cannot be obtained.

However, in conventional automatic welding equipment, even in such cases, the numerical control device is controlled based on error correction data provided from the calculation device, so it is difficult to align the torch with the V quasi-position. In some cases, it may not be possible to weld, or good welding results may not be obtained.

An object of the present invention is to provide an automatic welding device that prevents abnormal control operations from being performed due to abnormalities or malfunctions of the device.

[Means for Solving the Problems] The present invention provides a torch position adjustment mechanism for adjusting the position of a welding torch, and a mechanism for determining the deviation of the welding torch from a reference position and aligning the position of the welding torch with the reference position. an error correction data calculation device that calculates and outputs the error correction data necessary for the calculation, and a numerical control that uses the error correction data outputted by the error correction data calculation device as input to control the position of the welding torch to match the reference position. In an automatic welding device equipped with a device, abnormal control operations are prevented from being performed due to an abnormality in the device or the like.

Therefore, in the invention of the present invention, the error correction data outputted by the arithmetic device is input, and the error correction data given from the arithmetic device when at least one of the error correction data and the cumulative value of the error correction data exceeds the allowable range. A correction data monitoring and control device was provided to stop the control operation of the numerically controlled bag a.

In addition, in the invention of the present application cylinder 2, when the error correction data outputted by the arithmetic device is input and the error correction data exceeds the permissible range, the control operation of the numerical control I device based on the error correction data is stopped and the predetermined control operation is performed. A correction data monitoring and control device is provided that causes the numerical control device to perform control operations based on the correction data, and stops the control operations of the numerical control device when the cumulative value of error correction data output from the arithmetic device exceeds a permissible range.

[Operation of the Invention] When configured as in the first invention above, when at least one of the error correction data and the cumulative value of the y4 difference correction data exceeds the allowable range, numerical control is performed using the error correction data given from the arithmetic device. The control operation of the device stops. Therefore, it is possible to prevent control operations from being performed based on abnormal error correction data caused by abnormalities in the apparatus or the like.

Further, when configured as in the second invention, when the error correction data exceeds the allowable range, one control operation is performed using the error correction data output from the arithmetic unit as long as the cumulative value of the error correction data is within the allowable range. Instead of making t311!, correction data of a preset size is given to the numerical control device as error correction data. J] operation, it is possible to continue welding even if an abnormality in the equipment occurs temporarily, and it is possible to prevent welding from being interrupted due to a temporary abnormality. Furthermore, if the abnormality of the device is not temporary, the cumulative value of the error correction data exceeds the allowable range, so welding can be stopped.

[Example] The present invention will be described in detail below with reference to the accompanying drawings.

Fig. 1 shows an embodiment in which the present invention is applied to a consumable electrode type automatic arc welding device. The object to be welded, 3, is a welding power source, and the welding line W is the butt line between the objects 2, 2 to be welded.

Inside the welding machine main body 1, there is a welding torch 5 that supplies a consumable electrode wire 4 to the groove 2a (welding part) of the workpiece 2, and a welding torch 5 that oscillates (reciprocates) in the width direction of the groove 2a. Torch aiming position @ adjustment mechanism 7 that adjusts the oscillation position 6 and the aiming position of the torch 5 (the position of the oscillation center)
A torch vertical position adjustment mechanism 8 for adjusting the vertical position of the torch 5, and a torch position detection circuit 9 for outputting a torch position detection signal indicating the oscillation position of the torch 5 are provided.

The oscillating mechanism 6 is a mechanism that uses an electric motor M1 as a driving source to reciprocate the torch 5 in the width direction of the groove 2a.
The torch aiming position adjustment mechanism 7 is a mechanism that adjusts the position of the oscillation center of the torch by moving the pedestal supporting the oscillator 1 to the mechanism 6 in the width direction of the groove 2a using the electric motor M2 as a drive source. .

Further, the torch vertical position adjustment mechanism 8 is a mechanism that adjusts the vertical position of the torch (distance Plt between the torch and the workpiece) by vertically moving the pedestal supporting the oscillating mechanism 6 using the electric motor M3 as a drive source. Consists of electric 11M
By adjusting υItil of 2 and M3, the oscillation center (aim position) of the torch and the vertical position of the torch can be adjusted separately.

The torch position detection circuit 9 includes, for example, a speed generator T that detects the rotational speed of the electric separate M1 that drives the oscillator 1-1a structure 6.
Using the output of G as an input, it outputs an oscillation speed signal VO indicating the oscillation speed of the torch.

A wire feeding device 11 and a wire reel 10 are arranged near the welding machine main body 1, and the electrode wire 4 unwound from the wire reel 10 is supplied to the welding part through the wire feeding device 11 and the welding torch 5. Ru.

12 is an error correction data output device that calculates the deviation of the welding torch 5 from the reference position and outputs error correction data necessary for making the welding torch position coincide with the reference position at any time; 13 is an error correction device; This is a numerical control device that controls the position of a welding torch to match a welding reference position based on error correction data output by a data calculation device.

The reference position of the FJ contact torch 5 is the position of the welding line when controlling the torch to follow the welding line, and when controlling the vertical position of the torch, the reference position is the position of the welding line between the torch and the workpiece. These are set positions separated by a predetermined distance. Further, when controlling the welding start position, a preset welding start position U becomes the reference position.

The error correction data calculation device 12 is composed of a microcomputer, and detects the deviation of the position of the welding torch from the reference position by appropriate means, and calculates the error correction data necessary to eliminate this deviation, that is, the position of the welding torch 5. Calculate data on the amount of correction of the torch position necessary to make it match the reference position.

The numerical control device 13 inputs the error correction data output from the arithmetic device 12 and adjusts the torch aiming position adjustment mechanism 7 and the torch vertical position! i! i l+18 is controlled to move the pedestal supporting the oscillating mechanism of the torch by a predetermined amount to match the target position and vertical position of the torch with the reference position.

The positional deviation of the welding torch can be detected by electrically detecting changes in the welding current, by analyzing images of the torch and the workpiece obtained using an image sensor, or by detecting the position of the torch and the welding line. There are various methods such as providing detectors that mechanically detect positions and comparing the outputs of these detectors, and any of these methods may be used in the present invention.

For example, when a DC power supply having constant voltage characteristics is used as the welding part 11iQ3, the arithmetic unit 12
With the outputs of the welding current detector 14 and torch position detection circuit 9 as inputs, the position of the welding line determined from the welding current waveform and the positional change obtained from the torch position detection circuit 9 are used to determine the position of the welding line. positional deviation can be detected.

In other words, when using a welding power source with constant voltage characteristics, the second
As shown in the figure △, the torch 5 is moved in the width direction of the groove a-+b-
When welding is performed by oscillating as in +c-+b-+a, the arc angle 1-a is held almost constant due to the self-control property of the power source. Therefore, depending on the depth of the groove, the wire extension (length of protrusion from the torch 5) is Le1 →
e2-+ le3-+ le2-+ 181, and the welding current 1a changes periodically as shown in FIG.

In addition, a and C in Fig. 2 and Fig. 3 are respectively 1.-
b shows one end of the oscillation width and the point of panting, and b shows the center position of the oscillation. It is also assumed that welding proceeds from the front side of the paper in the figure in the direction toward the actual measurement.

As is clear from FIG. 3Δ, when welding the workpieces 2 which are butted together with a V-shaped groove having a symmetrical shape as shown in FIG. 2A, the oscillation center of the torch 5 is When the torch is aligned with the welding line W, the welding current Ia has a symmetrical waveform on both sides of the oscillation center, and the welding current 1a is at its minimum when the torch is located at the oscillation center.

On the other hand, as shown in Fig. 2B, when the oscillation center of the torch is shifted to the right side of the welding line W in the welding progress direction, the welding current 1a is as shown by the solid line in Fig. 3B.
The waveform becomes asymmetrical, and the position where the welding current 1a is at its minimum (the position of the welding line) is shifted to the left of the oscillation center of the torch.

Furthermore, if the oscillation center of the torch 5 is shifted to the left of the weld line in the direction of welding progress, the waveform of the welding current 1a will become as shown by the broken line in Figure 3B, and the welding current will be at its minimum. The position (position of the weld line) is shifted to the right side of the oscillation center position.

In this way, when using a welding power source with constant voltage characteristics,
Since the welding current changes depending on the groove shape, welding current 1
The position of the welding line W can be known from the waveform of a.

On the other hand, the torch position detection circuit 9 detects the oscillator i of the torch 5.
Taking advantage of the fact that the speed becomes zero at one end a and the other end C of the oscillation width and reaches the maximum at the oscillation center, the torch 5
The output of the speed generator TG that detects the oscillation speed of ■0
, two end position signals indicating that the torch is located at one end a and the other end C of the oscillation width, and a center position signal indicating that the torch is located at the oscillation center. Output.

The enclosure device 12 is necessary for comparing the data regarding the position of the welding line detected from the welding current waveform with the data on the oscillation center position obtained from the 1--chi position detection circuit 9, and aligning the oscillation center with the welding line. The correction speed of the torch position is calculated and output as error correction data every n/2 (n is a positive integer) period of the torch oscillation rate.

Furthermore, when the waveform of the welding current is integrated over a certain period of time, for example, over a half period of the oscillation, the integral value corresponds to the vertical position of the torch, so this integral value is used as a standard that indicates the reference position of the vertical position of the torch. By comparing the values, error correction data for the vertical position of the torch can be calculated.

In the present invention, the error correction data monitoring and control device 2 is provided between the error correction data calculation device 12 and the numerical control device 13.
0 is set. The supervisory control II device 0 shown in FIG. 1 corresponds to the first invention of the present application, and the arithmetic device 1
2, a data monitoring control means 21 which receives the error correction data P outputted by the error correction data P, and an allowable range setting means 22 which sets the allowable upper limit Q of the error correction data P and the allowable upper limit S of the cumulative value R of the error correction data. , an allowable correction data storage means 23 for storing the allowable upper limit Q of the error correction data P, and an allowable cumulative value correction data storage means 24 for storing the allowable upper limit S of the cumulative value R of the error correction data. The data monitoring control means 21 controls the control operation of the numerical control device based on the error correction data P given from the arithmetic unit 12 when at least one of the error correction data P and the cumulative 1iIIR of the error correction data exceeds a permissible range (upper limit value). make it stop.

The supervisory control device 20 can be configured by a microcomputer. FIG. 4 is a flowchart showing an example of a program when the supervisory control device 20 is configured by a microcomputer. When following the program shown in FIG. 4, when the error correction data P is input, first the newly input The error correction data is added to the previous error correction data to calculate the cumulative value R of the error correction data. Next, the permissible upper limit value S of the cumulative field stored in the permissible cumulative value data storage means 24 is read, and the cumulative value R is compared with the permissible upper limit value S. When l Rl > S? Z report device 2
5 drive signal is applied to generate an alarm, and the input of error correction data to the numerical control I equipment 3 is stopped to stop welding. Further, when IRI≦S, the allowable upper limit value Q of the error correction data P stored in the storage means 23 is read and the error correction data P is compared with the allowable upper limit value Q. I
When PI>Q, a drive signal is given to the alarm device 25 to generate an alarm, and the input of error correction data to the numerical control device 13 is stopped to stop welding.

Also, when IPI≦Q, the error correction data P is numerically controlled! I
l device 13 to cause the numerical control device 13 to perform a predetermined control operation.

In this embodiment, both the error correction data P and the cumulative value R of the error correction data are monitored.
In the invention, it is sufficient to monitor at least one of the error correction data and the cumulative value of the error correction data, and only the error correction data P is compared with the allowable upper limit value Q to determine whether the data P exceeds the allowable upper limit value Q. It is also possible to stop welding at times, or to compare only the cumulative value R of the error correction data P with the allowable upper limit value S, and to stop welding when the cumulative value R exceeds the upper limit value S.

FIG. 5 shows an example of the configuration of the monitoring and control device 20 in the invention of the present invention. In this case, a correction data setting means 26 and a setting correction for storing correction data ps set by the correction data setting means A data storage means 27 is added, and the output ps of the storage means 27 is transmitted to the data monitoring control means 21.
has been entered. The monitoring system 611 device 20 in FIG.
An example of a program configured by a microcomputer is shown in Figure 6. When following the program shown in Figure 6, it is necessary to always monitor both error correction data and cumulative value of error correction data. shall be carried out. When the cumulative value R of the error correction data is below the allowable upper limit value S and the error correction data P exceeds the allowable upper limit value Q, the error correction data given from the arithmetic unit 12 is used to control the numerical control device. +The control operation is stopped, and instead, predetermined correction data Ps is given to the numerical control device 13, and the control operation of the numerical control I table device 3 is performed using this correction data ps as error correction data. Further, when the cumulative value R of the error correction data exceeds the allowable upper limit value S, the supply of the error correction data to the numerical control device 13 is unconditionally stopped, and welding is stopped. The magnitude of the correction data PS is set to a value suitable for continuing welding without any trouble, for example, an average value of error correction data predicted in advance from the dimensional accuracy of the workpiece.

Further, the previous error correction data (error correction data before an abnormality occurs) may be used as the correction data Ps.

In each of the above embodiments, the tolerance range (upper limit) of the error correction data and the cumulative value of the error correction data may be uniform for each part of the workpiece, or may vary depending on the part of the workpiece. It is also possible to set a permissible upper limit value. In this case, which part of the object to be welded is currently being welded can be calculated from the elapsed time from the welding start time to the present and the welding speed, and according to the r8 welding part determined by this calculation. Then, a predetermined allowable upper limit value may be read out from the storage means and compared.

[Effect of the Invention] As described above, according to the invention of the present application, when at least one of the error correction data and the cumulative value of the error correction data exceeds the allowable range, the error correction data given from the arithmetic device is used. Since the control operation of the numerical control device is stopped, it is possible to prevent the control operation from being performed based on abnormal error correction data caused by a failure of the device or the like.

Further, according to the invention of the present application cylinder 2, when the error correction data exceeds the allowable range, the cumulative fi! of the error correction data! 1 (as long as ia is within the allowable range, correction data of a preset size is given to the numerical control device as error correction data instead of the error correction data output from the arithmetic unit, so that the control operation is performed. Welding can be continued even if the abnormality of the equipment occurs temporarily, and fail-safe can be achieved by preventing welding from being interrupted due to a temporary abnormality. If the error is not temporary, the cumulative value of the error correction data exceeds the allowable range, so welding can be stopped to ensure safety.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the present invention, and Figs. 2 and B show the operation of the torch when arc welding is performed by oscillating welding 1 and -, respectively. An explanatory diagram showing cases in which the welding current waveforms match the welding line and cases in which the welding line deviates from the welding line. Fig. 3A and B are diagrams showing the welding current waveforms in the cases of Figs. 1 is a flowchart showing an example of a program when the error correction data monitoring and control device is configured by a microcomputer, FIG. 5 is a block diagram showing the configuration of the monitoring and control device according to the invention in box 2, Fifth
2 is a flowchart showing an example of a program when the supervisory control device shown in the figure is configured by a microcomputer. DESCRIPTION OF SYMBOLS 1... Welding machine main body, 2... Work to be welded, 3... Welding power source, 6... Torch position adjustment mechanism, 12... Error correction data calculation device, 13... Numerical control device, 20...
- Correction data monitoring system t11 device, 21... Data monitoring control means, 22... Allowable range setting means, 23... Allowable correction data storage means, 24... Allowable cumulative value correction data storage means, 25. ...Alarm device. Figure 2 1 W
2 Figure 3 (A
(Figure 4)

Claims (2)

[Claims] (1) A torch position adjustment mechanism that adjusts the position of the welding torch, and a device that calculates the deviation of the welding torch from the reference position and calculates error correction data necessary to match the welding torch position with the reference position. An automatic welding device comprising: an error correction data calculation device that outputs; and a numerical control device that inputs the error correction data output by the error correction data calculation device and controls the position of the welding torch to match the reference position. In the above, the numerical control device receives error correction data output from the calculation device as input and receives error correction data from the calculation device when at least one of the error correction data and the cumulative value of the error correction data exceeds a tolerance range. An automatic welding device comprising a correction data monitoring and control device for stopping control operations. (2) A torch position adjustment mechanism that adjusts the position of the welding torch, and a torch position adjustment mechanism that calculates the deviation of the welding torch from the reference position and calculates error correction data necessary to match the welding torch position with the reference position at any time. and a numerical control device that inputs the error correction data outputted by the error correction data calculation device and controls the position of the welding torch to match the reference position. In the apparatus, error correction data outputted by the arithmetic unit is input, and when the error correction data exceeds an allowable range, the control operation of the numerical control device based on the error correction data is stopped, and the numerical value is adjusted using predetermined correction data. An automatic control device comprising a correction data monitoring and control device that causes a control device to perform a control operation and stops the control operation of the numerical control device when the cumulative value of error correction data output from the arithmetic unit exceeds a permissible range. Welding equipment.