SU753570A1 - Apparatus for automatic control of welding head displacement - Google Patents

Description

(54) DEVICE FOR AUTOMATIC REGULATION OF WELDING HEAD MOVEMENT The invention relates to automation in welding production and can be used in welding machines for automatic arc welding. A device for orientation of the electrode relative to the line of the welded joint is known, containing a scanning pyrometer attached to the welding head and a functional transducer, the output of which is connected to the drive for correcting the electrode position, and the input to the scanning pyrometer. This device allows you to adjust the position of the welding head on the minimum temperature field corresponding to the line of the welded joint 1. A disadvantage of the known device is the low reliability of the information obtained from the pyrometer due to the difficulty in minimizing the temperature field, especially with tight fitting of the edges to be welded. This disadvantage is also aggravated by the considerable inertia of the temperature field meters, which, under transverse vibrations from meters in conditions of different density of edge fitting, does not allow to obtain the required accuracy of the direction of the welding head along the connection line. In addition, the need to use a special meter located in front of the welding head, restricts access to certain connections, for example, to the internal grooves of box-shaped products. A device for automatically controlling the movement of a welding head is known, comprising a driver unit and a measuring unit connected in series, a functional converter, a comparison unit and a displacement drive. The automatic adjustment of the position of the welding head in this device is carried out by the signals of the position sensor 2. A disadvantage of the known device is its cumbersome nature, due to the presence of a position sensor mounted on the welding head. The consequence of this is the restriction of the access of the welding head to the grooves located close to the additional elements of the welded structures, which does not allow to obtain the required accuracy of adjustment by the position of the welding head. 1D (the invention is to increase the accuracy and control of the movement of the welding head along the connecting line of the welded ones. The goal is achieved due to the fact that the oscillating drive of the welding head is entered into the device, and the functional converter contains serially connected level quantizer, element for determining the sign of the derivative, trigger, logic element And the pulse counter, the master unit contains a pulse generator connected in series and a memory register, while the pulse generator is connected to the oscillation head of the welding head and the logic element I. Connecting to the measuring element connected to the electrode, a functional converter containing a series-connected level quantizer, a derivative sign determining unit, a trigger, a logic element AND and a pulse counter, allows for half a period of electrode oscillation across the connection lines fix the moment when the electrode passes the center of the groove, since the value of the measured parameter, for example, the voltage or arc current, will be at and m vary reach extreme values at the time of crossing electrode (inflated) line welded joint. Connecting a pulse generator to the drive of the electrode electrode, the memory register and the circuit I allows you to receive in the memory register the number of pulses corresponding to the no. Of the specified oscillation range of the 5.1 electrode, and from the output of the AND circuit connected to the pulse counter, the number of pulses corresponding to the magnitude of the transverse displacement of the electrode from one of its extreme positions until the intersection of the connection line. Comparison in the comparison unit of pulses corresponding to the uvine of the oscillation range and the pulse corresponding to the amount of electrode movement from the extreme position of the oscillation range until the electrode crosses the connection line recorded by the derivative sign mark tl.ioKOM, determine the direction and magnitude of the line deviation connections from the middle of a given range of vibrations. Due to direct measurement of voltage and; 1i arc current and the possibility of using low-inertia meters, the information on the position of the connection line relative to the welding head is provided, and the measurement can be made in each half-period of oscillation. Due to this, the required accuracy of adjustment by movement of the welding head along the connection line is ensured regardless of the density of fitting of the edges being welded. The drawing shows a block diagram of an apparatus for automatically guiding a welding head along a connection line. The device comprises a drive 1 for moving the welding head, a measuring unit 2 connected to the electrode 3, a drive 4 of the oscillator of the electrode 3, a master unit 5 including a pulse generator 6, the output of which is connected to the actuator 4 of the oscillator of the electrode 3 and through the switch 7 to the register 8 a memory, a comparison unit 9, a functional unit 10 containing a pulse counter 11, an I circuit 12, the output of which is connected to a pulse counter 11, and inputs to a pulse generator 6 and a trigger 13, a derivative sign definition element 14 and a level quantizer 15. The device works as follows. Before starting welding, the amplitude of oscillations of electrode 3 is set across the connection line and manually or by means of signals from the generator 6 of pulses applied to the actuator 4 of the oscillators of electrode 3, the electrode is brought to the extreme position of the oscillation range. Then set the switch 7 to the closed position and turn on the generator 6 pulses. The signals from the generator 6 pulses will be fed to the drive 4 of the oscillator electrode 3 and the register 8 of the memory. The pulse generator 6 is turned off when the electrode 3 reaches the middle of a predetermined oscillation range. In the register 8 pulses will be recorded the number of pulses corresponding to half the specified amplitude of oscillation of the electrode 3, the switch 7 is opened. After that, proceed to welding. When the welding head moves along the connecting line, the oscillator 4 of the pulse generator 4 receives oscillator signals from electrode 3. The change in the direction of movement of electrode 3 after each half cycle of oscillations can be carried out by the drive 4 oscillator of electrode 3. In each half oscillation of the electrode, generator b pulses also on the circuit 12 And further in the counter 11 pulses. Since the parameters of the arc, for example, the voltage or current, vary depending on its length, the magnitude of this change may be a characteristic of the length of the arc gap. When moving the electrode 3 in the process of oscillation across the junction line, this length changes and will be maximum in the middle of the groove. The task of the measuring element 2 and the functional converter 10 is to isolate the position of the extremum of the measured parameter relative to the middle of the oscillation range of the electrode 3. In this position, and a correction is made.

the position of the welding head relative to the connection line. The magnitude of the measured parameter in each half-period of oscillation is recorded by the measuring element 2, quantized by a level quantizer 15 and fed to the derivative sign definition element 14. When the measured value reaches an extreme value, i.e., when the electrode 3 crosses the line of the welded joint from one of its outputs, the derivative sign of the derivative sign 14 (depending on the direction of transverse movement of the electrode 3) will receive a signal that sets the trigger 13 to a position in which the supply from the output of the permitting signal to the circuit 12 is stopped. The signal to the circuit 12 And and to the counter 11 of the pulses of the generator 6 is also stopped. The number of pulses entering the counter 11 will correspond to the movement of the electrode 3 from the extreme position of the oscillation range to the position of the weld line, which corresponds to the position of the measured parameter extremum selected using the described scheme (voltage or current). The number of pulses received in counter 11 is compared in block 9 of the comparison in each half-period of oscillations with the number of pulses previously recorded in memory register 8. Since the number of the latter corresponds to half of the specified oscillation range of the electrode 3, it is possible to judge by the result of cp-avr about the magnitude and direction of deviation of the weld line from the middle of the oscillation range, i.e., the magnitude of the correction of the position of the welding head. The correction signals are thus received from the output of the comparator unit 9 to the drive 1 of the welding head. As a result, the welding head will move along

automatic welding lines

koi position correction depending

from the deviation of the specified line.

The device allows to obtain the required accuracy of the direction of the welding head along the connection line, regardless of the density of fitting the edges to be welded, by directly measuring the parameters of the welding mode and using low-inertia meters for the specified parameters. In addition, when using this device, there is no need to install a special sensor of the connecting line on the welding head, which will weaken the technological capabilities of the welding head by reducing its dimensions.

Claims (2)

1. USSR author's certificate number 548392, cl. At 23 K 9/10, 08/20/74. 2. Belenky, A. A. Ivanov, V. A. Automatization of production and instrumentation at non-ferrous metallurgy plants. M., “Metallurgists, p. 37, fig. 13.