JPS59183971A - Tracing sensor of weld line - Google Patents

Abstract

PURPOSE:To provide a titled tracing sensor which guides a weaving welding torch to the normal position in weld line tracking of said torch by comparing the right and left current values exceeding the blink sector of welding current and correcting the position of the torch so as to eliminate the excess value. 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 put through an amplifier into a comparting part 26. A current blink sector is set in the part 26 and the current value exceeding said sector is transmitted to a logical discriminating part 27. The current value is discriminated to the right and left by the right and left binary signals from a position detector 21 and a driving part 6 is moved by the signal from an instructing part 28 to correct the position of the torch 11 to the right or left so as to eliminate the excess current. The device 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 This invention is a welding sensor that follows a welding line while weaving a bath welding torch, and in particular, corrects a certain amount of left/right deviation of the welding torch with respect to the welding line when the welding current exceeds the dead band. This relates to line sensors.

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 part to be welded between L and 7R),
3 is the detection probe that detects the contact of welding 3, S is the controller, O is the left and right drive parts of the torch controlled by this controller 5, and 7 is the controller! gA, IiB, and gc are electric cables that connect the controller S with the detection globe, the torch left and right drive parts B, and the torch upper and lower drive parts 7, and t is the weaving Device,
10 is the detection probe l and weaving device? // is the welding torch attached to the weaving device Wa, 12 is the welding wire, //L is the position when the welding torch // is weaved to the left, //R is the welding torch // is on the right side This is the position when weaving.

In addition, the torch left and right drive parts B, the torch upper and lower drive parts 7,
The weaving device 9 and the holder /θ serve as a driving source for moving the welding torch // when the welding torch l/ deviates from the bath tangent line 3.

Next, the operation will be explained. First, a detection prober detects that the welding torch // has shifted from the welding line 3 for welding the objects /L and /R. The detected deviation signal is sent to the controller TA through the electric coupes KA, 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 sections 6 and the torch upper and lower drive sections 7 through electric capes NgB, f;C, respectively. The torch left/right drive unit 6
corrects the left and right positions of the weaving device, that is, the left and right positions of the weaving center of the welding torch //, and the torch upper and lower drive parts 7 simultaneously adjust the upper and lower positions of the weaving device, that is, the left and right positions of the weaving center of the welding torch //. Correct the top/bottom position.

Since the conventional rice equipment is constructed as described above, the detection probe must be installed in front of the arc generation position in order to avoid the effects of arc heat, light, and snow ivy. However, due to the misalignment between the detection glove setting position and the arc generation position, the detection accuracy decreases and a delay circuit is required, and the durability is also poor. Furthermore, since a detection glove is required, the device is complicated and expensive.

This invention was made in order to eliminate the above-mentioned drawbacks of the conventional method, and when the welding current exceeds the dead zone, the detection glove is This eliminates the need for the device, which makes the device simpler and more compact, allowing it to be applied to narrow welding areas.Furthermore, it does not reduce detection accuracy and durability even under harsh environments such as heat, light, and spatter that are typical of arc welding. The purpose of the present invention is to provide a weld line tracking sensor that can prevent

An embodiment of the present invention will be described below with reference to the drawings. Second
In the figure, /L, /R,,? ,A,? .

/a, //, //L, //R and /2 are the same as explained in FIG. Note that in this invention, the above-mentioned torch upper/lower drive section 7 is removed from the drive source. 2/ is a position detection device attached to the weaving device to detect the weaving position of the welding torch //, here is a welding power source, 23 is a current generator for welding current flowing from this welding power source 22 to the welding torch //, and cog is A return line for welding current, 2s is a detection part that detects the welding current, roller is a comparator that detects whether the welding current exceeds a predetermined dead zone, and 27 is a detection signal from this comparator roller and a position detector λl. The logic/discrimination section 2g determines the left/right deviation of the welding torch with respect to the welding object 3 based on the position signal of λ, and the logic/discrimination section 2g keeps the weaving device and thus the welding torch constant according to the discrimination signal from the logic/discrimination section λ. This is a command unit that sends a deviation correction signal to the torch left/right drive unit 6 to move the torch by an amount.

Next, the operation of the weld line following sensor of the present invention will be explained.

First, the weaving device 9 moves the welding torch l/ to the left in a plane perpendicular to the welding part 3.

When weaving, that is, periodic repetitive motion, is performed on the right R, the waveform becomes a sine wave as shown in Figure 3. Correspondingly, the welding current flowing through the current path 23 of the welding torch // also changes sinusoidally as shown in FIG. 3(B). This welding current is detected by the detection unit, and the conventional low-pass filters L, P, and F are used.
, extracts the alternating current component, amplifies it appropriately with an amplifier AMP, and then supplies it to the comparator 26. This comparator 2B outputs a detection signal to the logic/discrimination unit U? when the supplied welding current exceeds a predetermined dead band. supply to At the same time, based on the position signal sent from the position detector 2/ [Fig. 3 (K value electric signal shown in the figure corresponding to the weaving waveform of Shu]), the logic/discrimination unit Koku, for example, as shown in Fig. 3 CB ), the discrimination signal is not generated if there is no deviation, but as shown in Fig. 3 (C).
If it is "shifted to the left" as shown in FIG.
In this case, a negative polarity discrimination signal is generated.

This discrimination signal is supplied from the logic/discrimination section core to the instruction section 1g. Therefore, the command unit 2g sends a deviation correction signal to the driving source for moving the welding torch l/ by a certain amount, specifically, to the torch left/right drive unit 6, to correct the deviation of the welding torch /l with respect to the welding line 3. For example, the waveforms (C) and (D
For J, the command section 2g sends a deviation correction signal to the torch left and right drive sections B to move the welding torch l/ by a certain amount to the right and left, respectively.

Although the above-mentioned embodiment 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 of the welding current beyond the dead zone is corrected by a certain amount, so that the following effects can be obtained.

l Can detect weld lines without contact.

The device is simple, can be made into a shed, and is inexpensive, and can also be applied to narrow welding areas.

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

It is possible to provide redundancy in the setting of the welding S dead zone, which does not cause malfunctions or decrease in accuracy even with the noise peculiar to arc welding and the welding current with large fluctuations in the amount of bacteria.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing a conventional welding line tracking device, Fig. 2 is a partial block diagram schematic diagram showing an embodiment of the present invention, and Fig. 3 is a weaving position, welding current, and left/right deviation. FIG. /l...Welding torch?・・Weaving device, 3・・
Welding line 1.2S...Detection section, 2/...Position detector, 2B...Comparison section, 27...Logic/discrimination section, 2g...Command section,
A: Torch left and right drive parts. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Agent Shin Kuzuno - House No. A: Raijijig -8 Imakai--

Claims (1)

[Claims] In a device that follows a welding line while weaving a welding torch, a detection section that detects a welding current flowing through the welding torch, a position detector that detects a weaving position of the welding torch, and a detection section connected to the output side of the detection section. a comparison section for detecting whether the welding current exceeds a predetermined dead zone; a logic/discrimination unit that determines left/right deviation of the welding torch with respect to the welding line; and a drive source connected to the output side of the logic/discrimination unit that moves the welding torch by a certain amount in accordance with the discrimination signal for correcting the deviation. A welding line tracking sensor characterized by being equipped with a command section that sends signals.