SU650748A1 - Method of welding regulation - Google Patents

Description

frequency fluctuations of the intensity of the light radiation of the bath.

FIG. 1 is a diagram for implementing the method; in fig. Figure 2 shows a characteristic waveform with a record of the intensity of the radiation of the bath from the side of the arc and the back side of the joint. FIG. Figures 3, 4, and 5 show cxeiMa measurements of the intensity of radiation at different points of the arc column and the values of the frequency and amplitude of oscillations of the variable component of the intensity. The figures indicate the following: I - welding arc, 2 - electrode, 3 - welded product, 4 - light guide body, 5 - arc column area, b - photocell, 7 - variable frequency oscillation frequency detection unit, 8 - amplitude detection unit variable component oscillations, 9 — amplifier, 10 — actuator, 11 — welding current source, 12 — oscillogram of the radiation intensity of the bath from the arc side, 13 — oscillogram of the radiation intensity of the bath from the reverse side of the junction, 14-18 — radiation intensity measurement zone 19-20 is a graph of the variation of the amplitude and frequency of the variable component of the intensity in the initial state versus the distance from the arc axis, 21, 22 are graphs of the change of the above parameters at the moment when the arc torch exits the reverse side of the joint, 23, 24 - graphs of change of the specified parameters in the initial state depending on the distance to the metal being welded, 25, 26 - graphs of the change of the specified parameters when the arc torch exits from the back side of the joint, 27 - curve of the change in the amplitude of the variable component of the radiation intensity Bath depending on the zone of the signal registration zone.

The proposed method is carried out as follows. Excite arc 1 between the electrode 2 and the product 3. At the beginning of the process, when arc I between the electrode 2 and product 3 is burning through the optical fiber 4, the bath radiation in zone 5 hits the photocell 6, through which a current of 1 flows. Due to the fluctuations of the arc, the intensity of the radiation changes with a frequency of 1 / To (initial) and the amplitude of the AO. At the moment of the arc torch exit from the back side of the junction, the frequency decreases to I / T, and the amplitude increases to A variable component of the radiation intensity of the bath. The frequency change registers the block 7, and a variable component enters the input of the block 8, with a frequency of 1 / T and amplitude A. In block 8, when the amplitude reaches a predetermined value, it acts on the element and the signal amplified by the block 9 is output to the actuator 10. The latter or interrupts welding current from source 11 or starts

with a certain welding speed move the electrode.

In the graphs of FIG. Figure 4 shows the frequency and amplitude values of the variable component of the bath radiation measured in different zones of the arc column. It can be seen from the graphs that in order to receive a signal on the moment of arc torch exit from the back side of the junction with a maximum amplitude and frequency less than three times or more than in the initial state, the light guide 4 is directed perpendicular to the plane of the arc column and shifted to the peripheral one. part of the anode area, i.e., zone 14.

From the graph of FIG. 5 it follows that the area

zones are chosen in the range of 0.5-2.4 mm, which corresponds to 0.5-2.5% of the area of the anodic spot. The frequency of the variable component of the intensity of the radiation of the bath before the arc torch exits from the back side of the junction is 125-130 Hz, and the amplitude is 2-3 µs.

 At the moment when the torch of the arc exits from the back side of the junction, the frequency is 35-40 Hz, and the amplitude in zone 14 can reach 46.8 microns. Consequently, when the frequency is reduced, the moment of arc torch exit from the back side of the joint is determined three times more accurately.

The dimensions of the schv from the back side of the joint, as it was established, can be controlled by recording the number of minima of the variable component of the radiation intensity, each of which corresponds to the output of the arc torch from the back side of the joint.

The application of this method will allow you to develop a simple reliable system for automatically registering the moment when the arc torch emerges from the back side of the joint when penetrating-arc welding, which will significantly improve the quality of the shvov at the beginning of the process. This is especially important when welding pipe joints with a plasma arc and an electron beam. A device that implements this method will allow you to control the size of the melting in the process of welding butt joints with a pulsed penetrating arc.

Claims (1)

1. A method of controlling the welding process according to the intensity of the light radiation of the bath, detected by the photocell, characterized in that, in order to ensure high-quality welding of the butt joints by penetrating arc and simplify equipment, the frequency and amnlitude of the variable component of the intensity of the light radiation of the bath and the moment of occurrence of low-frequency radiation are measured. oscillations with an increased amplitude determine the output of the arc plume from the back side of the seam.