JPS58192682A - Automatic profiling method of weld line - Google Patents

Abstract

PURPOSE:To execute automatic profile welding which is simple and practical, and has reliability, by detecting a position of a welding torch against a weld line from comparison of values of both the left and right ends of oscillation, and controlling a position of the torch. CONSTITUTION:Wire extension LE and arc length LA are derived by providing a welding current, a wire feed speed, and voltage between a chip 3 and an work to be welded 12, to a computer 24, and LE+LA and a set value between the chip and the work to be welded are compared by a program of the computer 24. A result of comparison is outputted to a motor control power source 36, and a welding torch 1 is moved up and down by an up-and-down moving device 15. Also, a position of the welding torch 1 is controlled by driving a motor 16 and also moving a left and right moving device 17 to the left and right. In this regard, the position of the torch 1 is detected by an oscillation position detector 29, and is inputted to the computer 24 through an A/D converter 30. In this way, a distance between the chip 3 and the work to be welded 12 is kept constant, and also, even in case when the weld line and the groove line are shifted, the welding device corrects a track by itself.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for tracing a weld line in gas-shielded arc welding using a consumable electrode.

In the automation of welding and assembly of various structures, in order to ensure welding quality, it is important to make the retardation of the welding torch follow the welding groove accuracy width error. Methods using sensors such as III & HJ waves, electromagnetic valleys, and fluid elements, and methods using image sensors such as television cameras have been proposed.

However, in S871, it is necessary to attach a two-eye type sensor T-throat facing the bevel surfaces on both sides at or near the bath torch.

It is not practical in the case of complex handling and the intense high-temperature atmosphere caused by welding or the arc atmosphere with redundant fumes, as the heat resistance of Senna itself and the noise resistance due to the welding rope current are insufficient. In the latter case, a television camera or the like is installed above the front of the welding torch to determine the groove width by image processing, but this requires expensive equipment and also causes problems due to the source of the welding arc. malfunctions and practical reliability cannot be obtained.

Therefore, in view of the above-mentioned drawbacks, the present invention provides a practical and reliable automatic tracing method for welding lines that eliminates the need for sensor attachment and eliminates obstacles caused by complexity in structure, handling, high temperature, noise, cost, etc. The purpose is to provide.

The gist of the present invention for achieving the above object is to supply a consumable electrode through the tip of a welding torch toward a welding line of a welding material and to oscillate the welding torch to perform welding. Detects the electrode feeding speed and the voltage between the tip and the material to be welded,
Based on these values, the sum of the arc length and the protrusion length of the consumable electrode is calculated, and the relative position of the welding torch with respect to the welding line is completely detected by comparing the values of the left and right ends of the above sum by the oscillation of the welding torch. The feature is that the position of the welding torch is controlled so that the arc point follows the welding position when the positional relationship is 9.

Hereinafter, the welding line automatic tracing method of the present invention will be described in detail with reference to the tfiN plane.

FIG. 1 represents the principle of the invention. The bath welding torch L is connected to the welding device 2 and A, which includes metals such as a welding power source, and the tip of the welding torch 1 has a chisel in the center! 3 is attached, and a shield gas nozzle 4 that spouts shield gas to the outer periphery of -f: is attached. Then, the wire 6 wound around the reel 5 is passed from the base end of the welding torch l through the feed roller 8 driven by the wire feed motor 7 in the entire axial direction of the center of the welding torch l, and the wire 6 is passed from the base end of the welding torch l to the tip f3. It protrudes from the inner part. This wire 6 is connected to a drive control power source 9 of a wire feeding motor 7, and its feeding speed is controlled by V4. The base end of the welding torch l is attached to an oscillating device 11 equipped with a drive motor 10i, and the welding torch 713, which is adapted to make an oscillating motion with respect to the welding line of the workpiece 12, drives the driver motor 10i. It is a control power source. The oscillating device 11 has a driving r motor 14 for vertical movement lc! Attached to J device 15, vertical movement device #t15
is attached to a left/right moving device 17 equipped with a drive motor 16, and is machined to move the tip 3 of the tip C toward the workpiece 12.
The position of - can be changed. Note that the left and right moving device blt17 is supported by an arm 18 connected to a truck (not shown).

The welding torch I and its attached equipment are moved along the welding line by the trolley. In the figure, 19 is an arc generated at the tip m of the wire 6, 20 is a welding metal, and 21 is a shielding gas.

In gas-shielded consumable electrode arc welding using this device, there is a certain functional relationship among welding electric current I, wire feed speed M, arc voltage M, wire protrusion length LE% arc length Lm. Something has been experimentally obtained.

Therefore, as a variable necessary for control, wire feeding speed rtL
The above device is equipped with a mechanism for detecting the welding current I and the voltage between the tip and the object to be welded. As a mechanism for detecting the wire feeding speed, a rotation amount detector 22 such as a rotary encoder is attached to the feed roller 8KI, and an analog/dinotal converter (hereinafter referred to as t converter) 2 is attached.
3, the information is digitized and manually inputted to a digital computer (hereinafter referred to as a digital computer) 24 which performs arithmetic processing. Further, in order to detect the voltage v=1 between the tip 3 and the workpiece 12, a voltage value detector 25 including a potentiometer is connected to the chip 3 and the workpiece 12, and its output signal is sent to the converter 26. The information is input to the computer 24 via the computer 24. Furthermore, welding 111! II Welding device 2 and object to be welded 12 to be detected
A current value detector 27 such as an electric current value detector 27 is provided at 1;n, and its output signal is inputted to the computer 24 via a filter converter . Therefore, the position of the welding torch l is required as a control element, and therefore the oscillation device 11 is provided with an oscillation position detector 29 that detects the entire instantaneous oscillation position, and its output signal is A//l. )conversion'
4t 30 t- is input to the computer 24 via the computer 24. The computer 24 also includes a setting device 31 for setting the distance Ill LD between the hemorrhoid and the object to be held in advance.
is provided via the converter 32.

The computer 24 has a built-in circuit that calculates the position control amount of the welding torch 1 based on the above-mentioned inputs, and its output, a left/right movement control signal, is sent to a digital analog converter (hereinafter referred to as . It is input to the motor control power supply 34 which is the power supply of the drive motor 16 of the horizontal movement device 17 through the converter) 33, and the vertical movement control signal n1 or D/
The signal is input to the motor control source 36, which is the power source of the drive motor 14 of the E lower moving device 15, via the A converter 351r.

During welding, the rotation amount detector 22 detects the wire feeding speed V, the voltage value detector 25 detects the voltage between the tip and the workpiece to be welded, and the current value detector 27 detects the welding power source I.

These analog lids are A//1) It e device 23, 2
6.

It is converted into a denotal quantity by 28 and added to the computer 8!24.

By the way, I: M4 electrical connection fi (A) V: Wire feeding speed [(vm/s) V2 Voltage between tip 3 and workpiece 12 MLE: Length of wire 6 from tip tip to arc 19 That is, the wire protrusion length (■), the distance #1 from the tip of the LA wire 6 to the weld metal 201, that is, the arc length (■), Vlc: the voltage generated by the welding current I at the wire protrusion, ■mu: arc Assuming that the voltage is y, there is approximately the following functional relationship between the above iii.

l4-=fl(v, I)-11) ■Taku Sagi f
x (Ma, I, Lg)... (2) ■Mu=V-V,
・・・・・・(3) LA = 11(Vmu, I) ・・・・・・(4) (Equations 11 and (4) are
[Research on Current Controlled Arc M-Welding] (#l Welding Society Welding Method Committee July 1980) Welding Arc Dust Elephant Expanded Edition (Sanpo, Ans. 1ii1 Ko”F et al.) No. P 10S No. 31
27[1imVa −I ? The characteristic equation 9 can be obtained, and the specific form of equation (2) can be found by experiment. It should be noted that equation (3) is obvious from Figure 1 of Vim.

Therefore, if the relationship of equation (1) is made into a zologram for the electric machine 24 and the wire feeding speed V and bath & current Ii are given, then
The wire protrusion length LE is determined.

The relationship of equation (2) is programmed into the computer 24, and the wire feed speed V, welding! 117i1. By giving I and the wire protrusion length obtained by the above calculation, the voltage vE of the wire protrusion can be found.

The relationship t in equation (3) is programmed into the computer 24,
Voltage between the tip 3 and the object to be welded 12 (2) Processing If the voltage vE of the wire protrusion obtained by the above calculation is given, the arc voltage V can be determined.

The arc length LA can be determined by programming the relationship of equation (4) into the computer 24 and giving the fusion voltage flLI and the arc voltage VA obtained by the above calculation.

As mentioned above, if welding current 11 wire feeding speed V and voltage V between chip f3 and workpiece 12 are given as variables, from equations (1) to (4), wire protrusion and arc &L is required.

Next, the distance between the chip and the object to be touched is 31 and 1)/A.
With the converter 32, it is possible to use a direct LD!・
The distance between kisses sr is set and given to the computer 24.

The previously determined wire protrusion length, the arc ML sum (L, + LA), and the tip/workpiece open voltage value LD are compared using a zologram on the computer 24.

Then, the comparison result t'' is outputted to the motor control power source 36 through the A/A converter 35, the drive motor 14 is driven, and the welding torch is moved up and down by the vertical movement device 11b.

In the above-described manner, the distance setting device 31 between the tip and the workpiece to be welded is
KL controls the distance between the tip and the workpiece to an arbitrary value.

On the other hand, the lv contact torch 1 is oscillated by an oscillating device 11. When the welding torch 1t oscillator is not running,
When there is an intersection point (welding line) of the joint formed by the object l2 on the length of the wire 6, the welding torch l
As shown in the figure, oscillation is performed in the range of 'max' on the angle with respect to the axis tube connecting the center of oscillation and the above-mentioned intersection. The oscillation rate of the fg contact torch l is a simple harmonic (
If the entire pendulum motion or similar motion is performed, the distance between the tip and the workpiece (h,
, +LA) has a hazy shape in Figure 4. This means that when the oscillation angle of welding torch l is 0, the torch axis is
This figure shows the case where the angle is 45° with respect to the plane (7).As shown in Fig. 4, oscillate with θ=0 and the intersection of the joint on the length of the wire When all steps are completed, the distance between the tip and the object in contact with the oscillation angle # is
LK + LA) trajectory 1-1. , becomes symmetrical and θ=
'max (LE + LA) and θ knee θmax
When (L=+LA) becomes equal. i.e. #
= + am, , and -= -'mix (LE+
When LA) are equal, the intersection of the joints is on the extension of the oscillation center axis.

FIG. 3 shows a case where there is no intersection point of the joint formed by the workpiece 12 on the extension of the oscillating center axis of the welding torch l.
7'', but in this case as well, the oscillation rate is swung up to ±θmax with respect to the central axis. In this case, if the oscillation of the bath welding torch l performs a simple harmonic motion or a motion close to this parallel to the plane of the paper, the locus of the distance between the welded objects (Lh+L□) with respect to the oscillation angle Ife is shown in Figure 5. It takes shape. That is, at this time, as shown in Figure Wc5,
aX and one = −'max for le (LK + LA) +
7) Values are not local. Therefore, θ” 'max and θ
The motor 14i is driven to move the vertical movement device 15 up and down and the motor 16 is driven so that (14+LA) is equal to ``-'max.
Adjust the position of the welding torch by moving it left and right. Of course, this operating procedure! Log it. Note that the welding torch position 10 is detected by the oscillator position detector 29, and the electric
It is input to ff124.

Through the above-described operations, the distance 111 (L, +L) between the tip 3 and the workpiece 12 is kept constant during welding, and the tangent line and the groove edge are misaligned for some reason. The welding equipment can make all the trajectory corrections by itself even in the event of a failure.

As described above, according to the automatic weld line tracing method according to the present invention, the distance between the tip and the workpiece is automatically controlled, and the distance between the tip and the workpiece is always controlled symmetrically around the oscillation angle [t-Mma'. Therefore, the welding line can be automatically traced, and even if the welding line is initially rough, the welding can be performed with precision. Therefore, by applying it to a Kenpo t-S mouthpiece pit, etc., it becomes possible to perform highly accurate unmanned #handshake.

[Brief explanation of the drawing]

Figure 1 is a principle diagram of the automatic tracing method for the S welding rope according to the present invention, Figure 2 is an explanatory diagram showing a state in which the welding torch oscillates with the axis pointing toward the welding line, and Figure 3 is an explanatory diagram showing the state in which the welding torch is oscillated with the axis facing the welding line. An explanatory diagram of the welding torch oscillating around the axis that points to the position. Change in the distance between the proboscis to be welded? The diagram shown in FIG. 5 is a diagram showing the distance between the tip and the welded object - 〇 change k7J<s due to the oscillation rate r shown in FIG. 3. In the drawing, 1 is welding 1-chi, 3 is welding! . 6 is a wire, 11 is an oscillation device, 12 is a workpiece to be welded, 15 is a vertical movement device, 17 is a left/right movement device, 22 is a rotation proof detector, 24 is a Deinotal computer hinoki, 25 is a voltage value detector, 27 is a current 29 is an oscillating position detector, 34.36 is a motor control T source. 12 Figure 3 Figure 4 θ Figure 5

Claims (1)

[Claims] In arc welding, where the consumable electrode is supplied through the tip of the welding torch toward the welding line of the material to be welded, and the welding torch tube is oscillated to carry out welding, the welding current and the consumable electrode are supplied. Detect the speed and the voltage between the tip and the material to be welded, calculate the sum of the arc length and the protrusion length of the consumable electrode based on these, and then calculate the oscillation values at both left and right ends of the above sum by the oscillation of the welding torch. The relative position of the welding torch to the welding line is detected from the comparison, and the position of the welding torch is controlled so that the arc point follows the welding line so that this relative positional relationship is as set. Automatic copying method.