JPS59183979A - Tracing sensor of weld line - Google Patents

Abstract

PURPOSE:To provide a titled tracing sensor which guides a weaving welding torch to a normal position in weld line tracing of said torch by converting right and left current values of weaving to pulses, and controlling the position so that the width thereof is maintained equal and normal. CONSTITUTION:The wire 12 of a weaving torch 11 welds with the current of a welding power source 22. The current in a detecting part 25 is converted to a pulse width in a pulse width detecting part 26 and is put into a comparing part 27 in which a reference pulse width is set. The right, left, top and bottom of the torch are discriminated by a logical discriminating part 28 from whether the pulse width is larger or smaller than a reference value and the signal from a position detector 21. A lateral driving part 6 and a vertical driving part 7 are drived by the command from an instructing part 29 to guide the torch 11 to the normal position. The sensor makes detection without contact, permits simplification and reduction in size, is unaffected by environment and has reliability without malfunction.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a sensor for tracking a welding line by controlling the pulse width while weaving a welding torch. The present invention relates to a weld line tracking sensor that compares reference pulse widths and corrects left, right, upper, and lower deviations of the welding torch with respect to the welding current.

A conventional device of this type is shown in FIG. In the figure, /L and /R are the objects to be welded on the left and right sides, respectively, with respect to the direction of welding indicated by arrow Y, and 3 is the welding line (
In other words, the location where welding objects /L and /H are to be welded),
l is a detection probe that detects the welding line 3 by contact, S is a controller, B is a torch left/right drive section controlled by this controller s, and RI is a torch upper/lower drive section controlled by the controller S. gA, gB%gc are electric cables connecting the controller S and the detection probe, the torch left and right drive parts B, and the torch upper and lower drive parts 7, respectively. is a weeping device, IO
is a holder that holds the detection blower and weaving device @9, // is a welding torch attached to the weaving device 9, /, 2 is a welding wire, //L is a welding torch /
l is the position when weaving to the left, //R is the position when welding torch 1/ is weaving to the right.

In addition, the torch left and right drive parts B, the torch upper and lower drive parts 7,
The weaving device D and the holder 10 serve as a driving source for moving the welding torch l/ when the welding torch l/ is deviated from the welding line 3.

Next, the operation will be explained. First, a detection probe detects that the welding torch /l has deviated from the welding line 3 for welding the objects /L and /R. The detected deviation signal is sent to the controller S through the electric cable gA, which determines whether the deviation is left/right or up/down. As a result, controller S
The deviation correction signal is sent to the torch left and right drive parts B and the torch upper and lower drive parts 7 through electric cables gB and gc, respectively. This deviation correction signal causes the torch left/right drive unit 6 to move the welding torch to the left/right position of the weaving device wa.
The left and right positions of the weaving center of / are corrected, and the torch upper/lower drive unit 7 similarly corrects the upper and lower positions of weaving device wa, that is, the upper and lower positions of welding torch l/.

Conventional devices of this type are configured as described above, so in order to avoid the effects of heat, light, and spatter from the arc, the detection probe must be installed in front of the arc generation position, and therefore the detection This has disadvantages such as a decrease in detection accuracy due to the misalignment between the installation position of the probe and the arc generation position, and the need for a delay circuit, as well as poor durability. Furthermore, since a detection probe is required, the device is complicated and expensive.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and it detects the pulse width proportional to the magnitude of the welding current and compares the detected pulse width with a reference pulse width to determine the welding torch. By correcting deviations to the left, right, top, and bottom of the tangent line, a detection probe is no longer necessary, and the device can be simplified and downsized, making it suitable for welding in narrow spaces, as well as arc welding. specific heat, light,
The purpose of the present invention is to provide a welding line tracking sensor that can prevent deterioration in detection accuracy and durability even under adverse environments such as spatter.

An embodiment of the present invention will be described below with reference to the drawings. Second
In the figure, /L, /R13,6,7,9,10,//
, //L, //R and /+2 are the same as explained in FIG. λ/ is a position detector attached to the weaving device to detect the weaving position of the welding torch //, and here is a welding power source 5.23 is this welding power source 2.
The current path for the welding current flowing from 2 to the welding torch //, 2da is the return path for the welding current 1.2S is inserted into the current path 3 between the welding power source and the welding torch to detect the welding current. The detection part λB is connected to the output side of this detection part 25 and detects the pulse width proportional to the magnitude of the welding current.The pulse width detection part 1.27 is connected to the output side of this pulse width detection part. a comparison unit that compares the connected and detected pulse width with the reference pulse width;
ag is connected to the comparison section 27 and the output side of the position detector 21, and uses the comparison result signal from the comparison section 27 and the position signal from the position detector KO/ to determine whether the welding torch // is left or right with respect to the welding line 3.・Logic for determining upper/lower deviation・
The discrimination section 2q is connected to the output side of the logic/discrimination section 2g, and is a driving source for moving the weaving device M9 and eventually the welding torch/l according to the discrimination signal.
This is a command section that sends a deviation correction signal to the right drive section t or the torch upper/lower drive section 7.

Next, the operation of the welding line tracking sensor of the present invention will be explained.

First, a weaving device is used to weave the welding torch // in a plane perpendicular to the welding line 3 to the left and right. If the pulse width is controlled while weaving the welding torch /l in this way, the welding wire /λ of the welding torch // and the workpiece //
L.

//R changes periodically as is clear from FIG. 1, and therefore the welding current flowing through the current generator 3 of the welding torch /l also changes as shown in FIG. This welding current is detected by the detection section 5, and its pulse width is detected by the pulse width detection section 2A. Specifically, since the pulse width is proportional to the magnitude of the welding current, it gradually becomes wider at the center of the weaving, as shown in the figure, and becomes the widest at the left end of the weaving and the right end of the weaving. For example, the pulse widths detected at the left end of the weaving and the right end of the weaving are compared with the reference pulse width in comparison section 2B, respectively, and the comparison result signal is supplied to the logic/discrimination section -g. At the same time, a position signal from the position detector 2/ is also supplied to the logic/discrimination section 2g. From these two signals, the logic discriminator 2g determines the pulse width T detected at the left end of the weaving at 5 as shown in FIG.
When L > reference pulse width T and pulse width TR detected at the right end of weaving T, it is determined that the welding torch // is "shifted to the left" and, for example, a positive polarity signal is followed by a non-polar signal. A discrimination signal is generated, and when TL-TR=T, it is determined that there is no deviation, and a discrimination signal consisting of a non-polar signal is generated following a non-polar signal, that is, no signal is generated, and TL < T KatTR> T
At this time, it is determined that the welding torch /l is "shifted to the right" and a determination signal consisting of a non-polar signal followed by a positive polarity signal is generated.

Furthermore, when T>T and TR>T, the welding torch/l
T
<T and TR<T, it is determined that the welding torch // is lowered too much by 6, and a determination signal consisting of a negative polarity signal followed by a negative polarity signal is generated.The command unit 27, When these discrimination signals are received, the drive source for moving the welding torch/l is activated, specifically the torch left/right drive unit 6 or the torch top/l.
Below, a deviation correction signal is sent to the drive unit 7 to correct the deviation of the welding torch/l with respect to the welding line 3.

In addition, although the above example shows the case of downward butt welding,
It is equally effective for butt welding in other positions (horizontal, vertical, upward) and fillet welding in all positions.

As described above, according to the present invention, the deviation is determined by detecting the pulse width proportional to the magnitude of the welding current and comparing the detected pulse width with the reference pulse width. There is an effect.

l Can detect weld lines without contact.

The λ device can be made simple, compact, and inexpensive, and can also be applied to narrow welding areas.

3. There is no decrease in accuracy or durability even under adverse environments such as heat, light, and spatter that are typical of arc welding.

Hiro: It is possible to follow the welding line without malfunction or loss of accuracy even with the noise peculiar to arc welding and the welding current with large instantaneous fluctuations.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing a conventional weld line tracking device, Fig. 2 is a schematic two-part block diagram showing an embodiment of the present invention, and Fig. 3 is the relationship between weaving position, welding current, and detected pulses. The waveform diagram illustrating the waveform diagram shown in FIG. 3... Welding line, M... Torch left/right drive part, G... Torch upper/lower drive part, De-weaving device, L/... Welding torch, K/... Position detector, CO S...・Detection part 1.2
6. Pulse width detection section 1.27.. Comparison section, 2g.. Logic/discrimination section 1.29-. Instruction section. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Agent Makoto Kuzuno - Tsuta 3 Figure U Taima □ % 4 Figure procedural amendment "spontaneous" h-Hsu Office Director's Palace 1, case display Patent application Sho jff-! g23/issue 2,
Name of the invention Welding line tracking sensor 3 To the person making the amendment Representative Hitoshi Katayama Department 4, Agent (2) Drawing Contents of the amendment (1) The description of "moving part gh" on page 7, line 16 of the specification Correct as “moving part, gA”. (2) Correct the entry "Detected pulse" on line 14 of the specification source page to read i11:r "Detected pulse". (3) Page 6 of the specification, lines 75-1, “//L”
. The description of //RJ is corrected to "/L, lR", and the description of "current device" in the 17th line is corrected to "current path". (4) “Comparison section” on page 7, line 6 of Ming #1 book
The description will be corrected to read "comparison section 27." (5) The description of "non-polar signal" in the 16th line of page 7 and the 1st line of page g of the specification is corrected to "signal of negative polarity." (6) Correct the description “Upward is 9” in the qth line of page G of the specification ratio to “Downward”, and the description “Downward” in the 7th line has been changed to “Downward”.
"Rise," he corrected. (Drawing 81I is amended as shown in the attached sheet.

Claims (1)

[Claims] A device for tracking a welding line by controlling a pulse width while weaving a welding torch, which includes a detection part for detecting the welding current flowing through the welding torch, and a detection part connected to the output side of the detection part to detect the magnitude of the welding current. a pulse width detection section for detecting a proportional pulse width; a comparison section connected to the output side of the pulse width detection section for comparing the detected pulse width with a reference pulse width; and a comparison section for detecting the weaving position of the welding torch. A position detector is connected to the output side of the position detector and the comparison section, and the position signal from the position detector and the comparison result signal from the comparison section are used to control the left, right, and top positions of the welding torch with respect to the welding line. - A logic/discrimination unit that discriminates the lower deviation, and a command unit that is connected to the output side of this logic/discrimination unit and sends a deviation correction signal to a drive source that moves the welding torch according to the discrimination signal. Characteristic welding line tracking sensor.