SU761179A1 - Arrangement for following large-curvature butts - Google Patents

Description

The invention relates to the automation of welding processes, in particular to tracking systems for automatic control of the welding electrode when welding joints with significant curvature. five

A device for tracking along the junction of significant curvature, containing a welding head with a block of its transverse movement and a photosensor 10 directly located in front of the head with a block of its angular movement relative to the axis of the head and a sensor displacement control circuit, is known [1]. A disadvantage of the known device is the low accuracy of tracking due to the significant dimensions of the sensor node.

The aim of the invention is to improve the accuracy of tracking.

This goal is achieved due to the fact that the photosensor is equipped with two photosensitive elements, a moving aperture with two holes, a fixed aperture with two holes, and segments that can be scanned. At the same time, a driver, a converter and a comparator, as well as logic and search blocks are entered into the control circuit, the driver's input is connected to the sensor output, and the logic unit is connected to the comparator by one input,

2

and the other with the shaper outputs, one output with the transverse displacement unit of the head and the sensor angular displacement unit, and the other with the search unit, which, in turn, is connected with the output unit of the sensor angular displacement unit.

The proposed solution allows to improve the accuracy of tracking along the junction by combining the information device in a single compact sensor, which allows to receive information from two points of scanning at once.

FIG. 1 shows a block diagram of the proposed device; in fig. 2 - stress plots on various elements of the device.

The device contains a sensor 1 position of the joint, directed to the electrode 2 of the welding head and the plane of the edges 3 and 4 connected. the element of the channel joint 10 and the photosensitive element of the channel of the electrode 11.

The output of the sensor is connected to the control circuit, which is entered in series

V * ⁴

I

761179

connected shaper 12, the Converter 13 and the comparator 14, as well as blocks of logic 15 and search 16. The input of the shaper 12 is connected to the output of the sensor. The logic unit 15 is connected to the comparator 14 by one input, and the other to the outputs of the former 12, and one output to the transverse displacement unit of the head 17 connected to the transverse displacement mechanism of the head 18 and the angular displacement unit of the sensor 19 connected to the angular displacement mechanism of the sensors' ik 20. Another output of the logic block 15 is connected with the search block 16, which, in turn, is connected with the block of the angular displacement of the sensor 19.

The device works as follows.

The optical sensor scans the surfaces of the cooking electrode 2 and the edges 3 of the parts to be joined as they enter the weld pool in front of the welding electrode as it moves. The luminous flux emitted by the electrode illuminates the joined edges. Reflected light flux enters the lens 5, which projects the image of the joint to the mobile 6 and stationary 8 apertures of the light modulator 7. The moving aperture 6 with two holes is mounted on the axis and is driven by a magnetic field created by an alternating current network one hole successively intersects both holes-segments of the fixed diaphragm 8 of the junction channel and the electrode channel; the second hole of the movable diaphragm 6 intersects only the opening segment of the fixed diaphragm s interface channel. The luminous flux that has passed through the openings of the moving and stationary diaphragms falls on the condensers and photosensitive elements of the 10 channels of the joint and 11 channels of the electrode, respectively. The output voltage received from the channel 10 of the sensor is a sequence of pulses from two scanning points (Fig. 2 Πι), the duration of which Ί \ is determined by the time of passage of the apertures of the mobile diaphragm through the aperture of the stationary diaphragm, and the dip in the middle of the pulse τι and τ ₂ corresponds to the width of the gap in the joint. The output signal of the joint channel contains information on the position of the joint when scanning it with one hole at the near point and information about the curvature of the joint when scanning it with another hole at the far point. When the curvature of the joint changes, the impulse τι will be combined with the midpoint of the impulse L, and the displacement of the impulse х ₂ relative to the midpoint of the impulse Τι characterizes the magnitude and direction of the curvature of the joint. The output voltage ΪΛ of the electrode channel And from the sensor represents a sequence of pulses, the duration of which T ₂ is determined by the speed of rotation of the moving diaphragm and the diameter of the welding electrode 2. Shaper 12

5 extracts from the pulse sequences (ί / ι and and ₂ ) pulses, respectively, proportional to the width of the gap at the scan point (7 ₃ , and electrode pulses / _{6. The} converter 13 separates the pulses

10 junction of the near point of the scan; ί / ₄ and the pulses of the far point of the scan ίΑ into the pulses of two channels. To correct the direction of the electrode along the junction, near-point pulses are used.

15 scans (7 ₄ and electrode pulses ί} _6. To adjust the angular position of the sensor relative to the welding head, use the pulses from the far point of the scan and ₅ and the pulses from the electrode and ₅ .

20 When the axis of the electrode coincides with the axis of the joint, the electrode pulse is placed exactly in the middle of two pulses of the near-point scan (/ 3 = 74). Converter 13 produces pulses ΐί / ₇ and and _& , the duration of which / 5 corresponds to the time interval between the falling edge of the junction pulse of the near point of the scan and the leading edge of the electrode pulse, and the duration T ₆ corresponds to the interval

30 time between the trailing edge of the electrode pulse and the leading edge of the next pulse of the near point of the scan. The time intervals / ₅ and T ₆ pulses ί / ι and and _& are filled with pulses with a duration of 35–2 microseconds, a frequency of 100 kHz, and are sent to comparator 14 (FIG. 1), where the error signal of the position of the welding electrode is produced relative to the joint. The comparator also produces40 the error signal of the position of the optical sensor relative to the welding electrode when the curvature of the joint changes. In this case, the time intervals between the beginning of the pulse are compared.

45 of the electrode U ₆ (Fig. 2) and the beginning of the pulse of the far scan point ί / 5 and the end of the pulse of the electrode and ₆ . The generated pulses SP and \ ϋ _{12 are} also filled with pulses with a duration of 2 microseconds, often 50 of that 100 kHz. The comparator 14 determines the difference in the number of pulses in the packets arriving at its inputs. The differential signal from the comparator goes to logic block 15 and in the case of a signal from the nearest scanning point, the logic block passes this signal through search block 16 to the control unit of the actuator of the angular turn of the sensor 19 and allows the sensor to rotate relative to the electrode so that the scan line of the sensor and the tangent to the joint at the point of scanning was constant. In the absence of a signal from the near point of scan 65, logic unit 15 skips the output * ".. '

761179

five

The signal from the far point of the scan from comparator 14 to the control unit 17 is transverse movement of the welding electrode. In the case of short-term loss of information from both channels of the junction, logic circuit 15 includes a search circuit 16, which turns on the control unit for the actuating mechanism of transverse movement of the welding electrode until a signal appears at the exit of the junction channel. Installation of the sensor at the joint at the beginning of the work also takes place with the help of block 16.

Using information about the position of the junction at two scanning points, including the shaper, converter, comparator, logic and search blocks in the control circuit, allows the welding electrode to be controlled at the junction of significant curvature with high accuracy.

Claims (1)

Claim A device for tracking along the junction of a significant curvature, containing a welding head with a block of its transverse displacement and a photosensor located directly in front of the golovka with a block of its angular displacement relative to the axis of the head, and also tracking accuracy, the photo sensor is equipped with two photosensitive elements, a moving aperture with two openings, a fixed aperture with two openings-segments and installed with the capability of In this case, a shaper, a converter and a comparator, as well as logic and search blocks are entered into the control circuit, the shaper input is connected to the sensor output, and the logic block is connected to the comparator by one input and the shaper output to one input with the transverse displacement unit of the head and the angular displacement unit of the sensor, and the other with the search unit, which, in turn, is connected to the angular displacement unit of the sensor.