JPS63286276A - Position detecting system for arc welding - Google Patents

Abstract

PURPOSE:To perform the accurate arc welding with the simple constitution by moving a position sensor to a torch and detecting a joint from a point of discontinuity between the torch and members to be welded. CONSTITUTION:The position sensor 1 outputs laser light 7 to a thin plate 5 and detects an interval (d) between the position sensor 1 and the thin plate 5 by its reflected light. Further, the position sensor 1 moves by the torsional quantity (l) in the right and left directions. By this method, the distance (d) becomes discontinuous at a part of the joint 6 by moving the position sensor 1 in the right and left directions and it is possible to follow up the joint 6.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a position detection method in arc welding, and more particularly to a position detection method in arc welding that accurately positions a torch using a position sensor attached to the torch. Regarding.

[Conventional technology]

Conventionally, continuous welding of joints of objects to be welded by arc welding has been widely practiced. The important thing in this case is
The purpose is to automatically detect the position of the seam accurately and follow it. For this purpose, some devices use a solid-state camera or the like.

[The pause is when trying to invent or solve a problem]

However, systems using solid-state cameras and the like are relatively unsatisfactory, require software development, and have problems such as long processing times.

The purpose of the present invention is to solve the above problems and to accurately position the torch by using a position sensor attached to the torch.
An object of the present invention is to provide a position detection method for arc welding performed in the arc welding process.

[Means for solving problems]

In the present invention, in order to solve the above problems, as shown in FIG.
In the position detection method for arc welding, in which arc welding is performed by moving the
); and a seam detection means for detecting a seam (6) of a workpiece to be welded (5) from a discontinuous point detected by the position sensor (1). is provided.

[Effect]

When the position sensor is moved relative to the torch, the distance between the torch and the workpiece changes discontinuously at the joint.

This point is the joint of the member to be welded, and by following this point, arc welding can be performed accurately.

〔Example〕

An embodiment of the present invention will be described below based on the drawings.

FIG. 1 shows a schematic diagram of an embodiment of the present invention.

In the figure, 1 is a position sensor that detects the position,
Details will be described later. Reference numeral 2 is a motor, which moves the position control rod left and right using a rank and pinion mechanism (not shown). 3 is a torch, 4 is a welding wire, and 1 is a welding wire. 5 is a thin plate (member to be welded), and here it is two thin plates. Reference numeral 6 indicates a joint between the thin plates 5, and if the welding wire 4 accurately follows this joint 6, accurate arc welding can be performed.

FIG. 2 shows a diagram explaining the operation of the position sensor 1. In the figure, a position sensor 1 outputs a laser beam 7 to a thin plate 5,
The distance d between the position sensor 1 and the thin plate 5 is determined by the reflected light.
Detect. Further, the position sensor 1 moves by a certain amount in the left and right directions.

As a result, the distance d becomes discontinuous at the seam 6 as the position sensor l moves left and right, allowing the seam 6 to follow.

FIG. 3 shows the relationship between the position sensor 1 and the detection distance d. In the figure, the horizontal axis indicates the moving distance of the position sensor I, and the vertical axis does not indicate the distance d between the position sensor I and the thin plate 5. As shown,
The point sequence becomes discontinuous at the seam 6, and the seam can be easily detected.

FIG. 4 shows a detailed diagram of the position sensor 1. In the figure, 1
is a position sensor, 11 is a laser drive circuit, and 1
2 is a semi-sensitive laser oscillator which oscillates and outputs laser light. Reference numeral 13 is a projection lens for focusing the laser beam. 1
4a is the position of the object to be measured, 14a is the reference point,
14b is above the reference point, and 14c is below the reference point.

Reference numeral 15 denotes a light-receiving lens, which receives reflected light of the laser beam and condenses it. The focused laser beam is projected onto the optical position detection element. The optical position selection element 16 is an element that converts the position where the laser beam is projected into an electrical signal. When the object to be measured is at the reference point as shown in the figure, the laser beam hits the center of the object and the object is detected. When it is on the top, it moves toward the lower right of the optical position detection element 16, and when it is opposite, it moves toward the upper left. This is output as an electrical signal, which is amplified and used by amplifiers 17a and 17b.

As explained above, by moving the position sensor, a discontinuous point in the distance between the position sensor and the thin plate can be detected, a seam can be detected from this, and arc welding can be performed accurately and continuously.

In the above embodiment, a position sensor that uses laser light is used as the position sensor, but it is not limited to laser light, and other types of sensors can also be used as long as they can measure the distance between the sensor and the thin plate. .

Furthermore, although the object to be welded has been described as a thin plate, the present invention can also be applied to other objects to be welded, such as welding a thin plate to a thick plate. moreover,
Although the position sensor was moved linearly in a direction perpendicular to the torch, it is also possible to detect discontinuities by rotating it.

〔Effect of the invention〕

As explained above, in the present invention, the position sensor is moved relative to the torch and the joint is detected from the discontinuity point between the torch and the workpiece to be welded, so that accurate arc welding can be performed with a simple configuration. be able to.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 is a diagram in which the position sensor is moved to measure distance, and Fig. 3 shows the moving distance of the position sensor and the distance between the position sensor and the workpiece to be welded. Figure 4 is a detailed diagram of the position sensor. ■ -・------One position sensor 2------Motor 3--------- Torch 4------
Welding wire 5 ------- Thin plate (member to be welded) 6 ''------
-----First seam

Claims (4)

[Claims] (1) In the position detection method in arc welding, in which arc welding is performed by moving a welding wire along the joint of the workpiece, a position sensor is movably attached to the torch, and an error in the position detected by the position sensor is used. 1. A position detection method in arc welding, comprising a seam detection means for detecting a seam of a welded member from a continuous point. (2) The position detection method in arc welding according to claim 1, wherein the position sensor moves in a direction perpendicular to the torch. (3) The position detection method in arc welding according to claim 1, wherein the position sensor fixes one point of the torch and rotates by a predetermined angle. (4) The position detection method in arc welding according to claim 1, wherein the position sensor is a laser position detector.