JPS62168677A - Welding start point detecting device in weld line copying device - Google Patents

Abstract

PURPOSE:To improve the detection accuracy by fixing a slit light source and an observation use optical system together with a welding torch, and also, making a point where each center axis of the slit light source and the observation use optical system crosses coincide, etc. with a welding target point of the welding torch. CONSTITUTION:A slit light source 6 and an observation use optical system 10 of a semiconductor laser, etc. are fixed together with a welding torch 2, to fixing jig 4 which has been provided on a wrist 3 of a robot. In this case, a point where the center axis of the light source 6 and the center axis of the optical axis cross is made to coincide with a welding target point of the welding torch 2. Also, a plane which is formed by a slit light beam 5 and each center axis of the optical system 10 is constituted so as to make a prescribed angle against the center axis of the torch 2. According to this method, since a detecting optical system 1 is fixed together with the torch 2, even in case an object to be measured 11 and the torch 2 approach each other, the detection can be executed, and the accuracy for detecting a welding start point is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a welding line copying device, and particularly to a welding starting point detection device suitable for detecting a welding line shift at a welding starting point.

[Conventional technology]

A conventional detection device of this type is disclosed in, for example, Japanese Patent Application Laid-Open No. 55-1.06.
As described in Japanese Patent No. 675, the slit light was projected so that the surface formed by the slit-shaped light beam was approximately parallel to the line connecting the light source, the torch, and the camera.

[Problem that the invention seeks to solve]

In the above-mentioned conventional example, when detecting the welding start point, if the welding start point is a complicated object to be measured, the slit light source or the i8+11 optical system comes into contact with the object to be measured, making it impossible to detect it.

SUMMARY OF THE INVENTION An object of the present invention is to provide a welding start point detection device that detects a weld line shift at a welding start point without colliding with an object to be measured.

[Means for solving problems]

In order to achieve the above object, the present invention includes a slit light source for irradiating a slit-shaped light beam to a fixing jig for fixing a welding torch to a welding torch position control means, and a fixing jig for fixing a welding torch to a welding torch position control means. 1!3 of the optically sectioned image formed on the object to be measured! Attach the optical system for measuring m 8111, and when installing, the plane formed by the central axes of the slit light source and the optical system for viewing 811 is formed by the central axis of the welding torch and the rotation axis of the welding torch position control means. The welding torch position control means is perpendicular to the plane in which the welding torch is positioned, and the intersection line is fixed within the angle formed by the welding torch central axis and the rotation axis of the welding torch position control means.

[Function] The slit light beam irradiated from the slit light source forms a light cut image on the object to be measured, and this light cut image is aAllIAl
R81 in l series! I will be treated. At this time, since the detection optical system is attached to the fixed jig as described above, the slit beam is always irradiated onto the object to be measured, and the light sectioned image on the object is always attached to the observation optical system. observed by.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 6.

A detection optical system 1 for detecting the position of the welding line is fixed together with the welding torch 2 to a fixture 4 fixed to the wrist 3 of a robot, which is a means for controlling the position of the welding torch 2. The detection optical system 1 includes a slit light source 6 such as a semiconductor laser that irradiates a slit-shaped light beam 5, and an observation optical system 10 that observes a light section image formed on the object to be measured 1 when the slit light source is irradiated. The observation optical system 10 includes a lens 7, a mirror 8, and a solid-state image sensor 9.

A plane formed by the central axis of the slit beam 5 and the central axis of the observation optical system 10 is configured to form a predetermined angle with the central axis of the welding torch 2, and the plane is parallel to the welding torch 2. It is configured so that Further, a plane formed by a line equally dividing the angle formed by the central axis of the slit beam 5 and the central axis of the observation optical system 10 and the central axis of the welding torch 2 is perpendicular to the direction of movement of the welding torch 2. It is composed of

Furthermore, the point where the central axis of the slit beam 5 and the central axis of the observation optical system 10 intersect coincides with the welding target point by the welding torch 2.

3 and 4 schematically show the principle of detecting a weld line by the optical system of the detection device shown in FIGS. 1 and 2. FIG. Here, the coordinate axes of x, y, and z have the welding point by the welding torch 2 shown in FIGS. 1 and 2 as the origin O, and the central axis of the robot's wrist 3 as the The direction is the X-axis, and the Y-axis is perpendicular to the direction of travel.

Here, the irradiation angle of the slit beam 5 and the *
8111 The angle that the central axis of the optical system 10 makes with the normal to the traveling direction is equal and is represented by the angle α, and the plane formed by the central axis of the slit ray 5 and the central axis of the observation optical system 10 is
Let the angle formed with the axis be 0. The coordinate axes of the solid-state image sensor 9 are the U-axis parallel to the X-axis and the Y-axis perpendicular to the U-axis, and the imaging magnification of the light sectioned image by the lens 7 (however, the magnification is based on the origin ○) Let be A.

FIG. 4 shows how the optical system of the detection device shown in FIGS. 1 and 2 detects the positional deviation of the weld line of the stacked plate joint. In the figure, the O mark (coordinates x, y, z) indicates the position of the weld line to be detected. The position of the weld line is
When the welding torch 2 shifts from its origin (point 0 shown in FIG. 3), the irradiation position of the slit beam 5 on the joint shifts accordingly. Then, the positional deviation of the welding line is determined from the optically sectioned image formed on the solid-state image sensor 9 at this time.

Figures 5 and 6 show optical section images obtained when welding a stacked plate joint. In both cases, the welding line is calculated from the coordinates (upV) of the end point near the center of both sides of the lower optical section line using the following formula: (1)
, (2).

X=u/ (2A cos a>...
・(1) Y=v cos O/A+u sin θ/
(2A sjn a> −(2,)Z=−vsj, n
o/A+u cos O/C2A sin a)-(3
) This is because the X-axis has already been set parallel to the advancing direction of the welding line as shown in Figures 3 and 4.

The deviation of the welding line position in the Y and Z directions obtained by equations (2) and (3) becomes the value to be determined by the detection device.

FIG. 7 shows the hardware configuration of a welding robot incorporating the weld line copying device according to the present invention. The detection optical system] is fixed to the wrist of the welding robot 12, and the optically sectioned image obtained by the detection optical system 1 is transmitted to the processing device 13 via the cable 14. The optically sectioned image is processed by the processing device 13, and the processing results are displayed on the monitor 16 via the cable J5. At the same time, the results of detecting the deviation of the welding line are transmitted to the robot control device 18 via the cable 17. The teaching line is modified in this control device 1.8.

The welding route is taught to the welding robot 12 by a teaching box 19. Further, the welding wire is supplied from the bobbin frame 20 to the welding torch 2 via the conduit cable 21.

Shielding gas during welding is supplied from a gas cylinder 22, and welding current is supplied from a welding power source 23 to the welding torch 2 via a conduit cable 21, respectively.

FIG. 8 shows an example of application of the detection device according to this embodiment. Detection is also possible when the welding torch 2 and the object to be measured 11 approach each other as shown in FIG.

As described above, according to this embodiment, since there are no attachments associated with detection around the welding torch 2, there is an advantage that the present embodiment can be applied to even complex welding objects.

Conventionally, due to variations in component dimensions or mounting positions,
It also has the effect of automating the welding of thin plate parts, which previously had to be done manually because robots could not perform accurate welding. Another advantage is that a special welding torch is not required for detection, and the welding torch can be easily replaced.

〔Effect of the invention〕

According to the present invention, the welding start point can be detected without the detection optical system coming into contact with a complex welding member.

[Brief explanation of drawings]

FIG. 1 is a side view of a detection optical system according to an embodiment of the present invention, FIG. 2 is a front view of FIG. 1, and FIGS. Figures 5 and 6, which are diagrams explaining the principle of the detection method using the optical cutting method, show detection screens obtained by the optical cutting method when welding a stacked plate joint with the configuration shown in Figs. 1 and 2. 7 are diagrams showing an example 5 of a system implantation of a weld line copying device to which the present invention is applied, and FIG. 8 is a diagram showing an application example of the detection device shown in FIGS. 1 and 2. 1... Detection optical system, 2... Welding torch, 3...
Robot wrist, 4... Fixing jig, 5... Slit light beam, 6... Slit light source, 9... Solid-state image sensor,]
-〇...11! Measurement optical system, 11... object to be measured, J
2... Welding robot, 13... Processing device, 18...
・Robot control device.

Claims (1)

[Claims] a welding torch, a position control means for controlling the position and posture of the welding torch by teaching a welding route and reproducing the taught route, a slit light source for emitting a slit-shaped light beam, and a device to be measured when irradiated with the slit light beam. It is equipped with an observation optical system for observing a light cut image formed on an object, and a processing device for processing the cut image, and detects the amount of deviation of the welding line with respect to the welding torch at the welding start point taught by the position control means. In the welding line copying device configured to detect the welding line, the welding torch is fixed to the position control means so that the welding point is a point where the central axis of the welding torch and the rotation axis of the position control means of the welding torch coincide. The slit light source and the observation optical system are mounted on a fixing jig so that the plane formed by the center axes of the slit light source and the observation optical system is relative to the plane formed by the center axis of the welding torch and the rotation axis of the position control means. A welding start point detection device for a welding line copying device, characterized in that the welding start point detection device is orthogonal to each other and fixed so that the intersection line of the two surfaces falls within the angle formed by the center axis of the welding torch and the rotation axis of the position control means.