JPS58181477A - Method and device for automatic welding - Google Patents

Abstract

PURPOSE:To improve the welding quality of automatic welding, by detecting the groove of materials to be welded as coordinates in a coordinate system on the image plane of an image sensor, and controlling welding conditions in accordance with the shape and position of the groove obtained by arithmetic processing of the coordinates. CONSTITUTION:The welding groove 4 of materials 1, 2 to be welded is irradiated with slit light 6 and the sectional shape of right angle is converted to a linear image 8 and is detected as a video 13 with an image sensor 9. The video 13 is detected as the suitable coordintes in the X-Y coordinate system in the image plane 10 of the sensor 9. The aiming position and angle of the torch 5 as well as welding conditions such as welding voltage, current or the like are controlled in accordance with the shape and position of the groove 4 obtained by arithmetic processing of said coordinates with an arithmetic controller 11, whereby the automatic welding is accomplished with good quality.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic welding method and apparatus, and is suitable for welding horizontal joints of side plates using %V.

Conventionally, the end point, inclination, and curvature of the slit image obtained by irradiating a slit-shaped light beam onto the groove of the welded material are determined as the characteristics of the slit image, and the deviation between this and the previously determined known one is calculated. The position of the groove was detected by looking at the groove, and based on the detection result, the welding torch attached to the tip of the movable arm was moved while welding.

In this conventional case, the position is detected by looking at the deviation between the slit image of the groove and the known one, so the groove cross-sectional shape is similar to each other at any decimal position or has a common feature that is the target. Otherwise, it will be impossible or inaccurate to detect the entire position, and although it is fine if the entire welding is completed with only one pass, it cannot be applied when four welds are performed using multiple passes, and the Since it only detects the tip position yt and does not detect the difference in shape, it is possible to adjust the suitable aiming position and angle of the welding torch, welding voltage, and
There was a problem in that the current and other welding conditions could not be determined, and the cause of welding defects could be determined. The present invention aims to solve the problems in the conventional case, and firstly, the groove of the material to be welded is obtained by irradiating the groove with beam-processed light from an arbitrary fixed distance to the groove at a fixed angle. A linear image expressing the shape of A target position of the welding torch based on the shape and position of the groove obtained by detecting the image of each point on the linear image as coordinates using a coordinate system having an origin at the position, and calculating the coordinates; The automatic welding method is characterized by controlling the angle and other welding conditions as necessary.Secondly, the device for fully welding the horizontal joints of tanks 9111 and 9111 is equipped with an adjustable welding torch and a beam-treated A light source, an image sensor disposed at a certain position diagonally horizontally with respect to the light source, and receiving and processing signals from the image sensor, as well as the aiming position and angle of the welding torch, welding conditions, etc. The present invention aims to provide a complete automatic welding device characterized by a computer and control unit for controlling the welding torch, an operating mechanism for the welding torch, and a common traveling frame, which is lowered from the upper surface of the upper tank side plate via wheels. It is.

As an embodiment of the method and apparatus according to the present invention, application to butt welding of horizontal joints of tank side plates will be described. In FIG. [When performing fully automatic bath welding of these horizontal joints 8 as welding materials, it is necessary to fully adjust the aiming position and angle of the welding torch 5 based on the results of detecting the shape of the groove 4 and its extent W at the location to be bath welded. There is. Beam-processed light, for example, a slit light from a 6ft light source 7, is irradiated onto the groove of the welded material at an arbitrary constant angle. For the sake of simplicity, if this angle is maintained at a constant angle (and therefore perpendicular to the side plates 1 and 2), a linear image 8 representing the entire right-angled cross-sectional shape of the groove is obtained. This image 8 is captured as an image 18 from an obliquely lateral direction as shown in FIG. 2 by an image sensor 9 held at a constant distance and at a constant angle with respect to the light source 7 and the workpiece to be welded. and image sensor 9
X
- Completely set the y coordinate system, and each point kx on the image 1B of the image 8
-y coordinate system, and based on the fact that the image sensor 9 is held at the constant distance and constant angle, the coordinate system calculation control unit [11 calculates and processes the groove 4. Shape and position captured from the front of a right-angled section 12? It is detected as the coordinates of the X-y coordinate system. x
The relative position of the origin 0 of the -y coordinate system in the vertical and longitudinal directions with respect to the material to be bathed must remain constant within the range of tolerance. In the case of this embodiment, as shown in FIGS. 8 and 4, the vertical dimension from the upper surface of the upper side plate 2 to the groove 4 is constant, and the upper side of the tank side plate and the layer side are Each of the traveling frames 21 and 21 on which all the equipment for welding from both sides is mounted is integrally connected at the entire upper part, and the wheels 16 and 17 are pivotally supported below the upper part of the frames.
The entire pedestal 21, 21' is suspended from the upper surface of the upper side plate 2. A welding torch 5,
A light source 7 for beam-processed light, an image sensor 9, and an arithmetic and control device 11. The operating mechanism of the welding torch 5, such as a servo motor 14 and a flux receiver, are attached to a belt 19, 19 and pulleys 18a, 18b, 18b and 18b. The image sensor 9 is arranged at a certain position diagonally horizontally with respect to the light source 7, and is pivoted near the bottom of the #contact torch 5.
The flux receiver wrapped around the pulley is a bell) 19
When the side plate 19i is pressed from both the front side and the back side, the image sensor 9 is held at a constant position in the front-rear direction by completely holding the side plate 1, and the frame 4z is pressed through the wheels.
1. By lowering zl'yH, the position can be held constant in one direction, up and down. A groove 20 inclined with respect to the generatrix is formed on the surface of the portion where the wheels 16 and 17 contact the upper surface of the side plate.
Wheels 16.1? ') It is desirable to use both as driving wheels in order to fix the origin O.

From the coordinates (XO) of an arbitrary point on the image 1B of the linear image 8 captured by the image sensor 9 from an oblique lateral direction, the coordinates (X
+, Yr) can be approximately determined by the following relationship, for example. When the image sensor 9k is projected onto a plane perpendicular to the Y-axis, the angle θX is formed with respect to the Z-axis (direction along the welding line) perpendicular to the X-axis, and image sensor 9 is projected onto a plane perpendicular to the X-axis. Angle sometimes made with respect to the Z axis? When θy is assumed and the image magnification is S, it is approximately expressed as −. This calculation is performed for each necessary point on the image 1B by the arithmetic and control unit 11, and the shape and position of the perpendicular cross-sectional contour of the groove 4 when captured from the front are detected as the coordinates of the kx-y coordinate system, and the shape captured from the front is detected. An image 12 of the position is obtained. This statue 12
A representative point representing the groove cross-sectional shape and position is extracted from the numerical group consisting of the coordinates of each point above. For example, in Fig. 5, the positions of the side plate base material surface @A and B1, the end points C and D of the base material, the point E representing the groove surface on the extension of the base material surface, and the top H of the bottom 01 mountain in the depth direction of the F1 groove. etc. are the representative points. Based on the coordinates of the representative points, the arithmetic and control unit [1i11] calculates the depth of the groove, W1, the cross-sectional area of the groove, a1, the frontage of the groove, the deviation d of the upper and lower side plates, etc., and the coordinates of each representative point. All welding conditions such as the aiming position and angle of the welding torch 5, welding current and voltage, and speed are controlled accordingly.

For example, regarding the aiming position of the welding torch 5, aim at all points 81111 from the back of the groove, or aim at the depth of the groove at the 9th position with a certain ratio of the groove width, etc. Regarding the angle of the welding torch 5, The angle when the end points C and D of the base material and the bottom G of the groove are connected with a straight line/CGD1fr can be determined by a method such as aiming for the ideal angle at a constant ratio. welding current,
Regarding voltage, etc., for example, the cross-sectional area of the groove recess is calculated, and based on the size of this cross-sectional area, the required amount of metal to be welded can be determined, and the amount of heat input, in other words, the required current and other welding It is possible to calculate the conditions.

The operation of welding conditions such as the aiming position, aiming angle, and welding current voltage of the welding torch, as well as the running speed of the gantry, is performed by the servo mechanisms 14 and 15 in response to signals from the arithmetic and control unit 11.
Each is performed by

The vertical and horizontal position adjustment mechanism of the welding torch 5 is, for example, a combination of a rack and a binion, or a combination of a servo motor and a binion (not shown), and the orthogonal 2
The mechanism for swinging back and forth, left and right around each shaft is, for example, a combination of a cam and a lever (not shown).

When only one side of the front side or the outer side of the side plate is fully welded, the light source, image sensor, operating mechanism, welding torch, etc. necessary for automatic welding may be mounted only on the frame on the side to be welded.

To explain the effects of the present invention, the entire coordinate system with the origin is set at an arbitrary constant position on the image sensor's image screen, and the shape and position of the groove of the welded material from the front are completely set. Based on the shape and position from the front, the target position, angle, welding current, and other welding conditions of the welding torch are all controlled, and as in the conventional case, the coordinates are detected as the coordinates of the coordinate system and the welding conditions are controlled based on the shape and position from the front. ≠ Since the method of seeing the entire deviation is not available, the cross-sectional shape of the groove is completely different at multiple positions, and the common characteristics g1. Even if you do not have a welding torch, it is possible to accurately detect the shape and position of the groove, and to set suitable welding conditions such as the aiming position of the welding torch, angle, welding current, voltage, etc. according to the detection results. Because of this, it can be applied to welding multiple buses and multiple layers, and high-quality automatic welding can be achieved.

[Brief explanation of the drawing]

Both figures are for detailed explanation of the present invention. Figure 1 is a perspective view of the signal flow and the position of each part, and Figure 2 is a diagram showing the shape and position of the groove cross section as seen from an oblique stack. The relationship in the coordinate system when viewed from the front is shown. Figure 8 is an external side view of the welding equipment lowered to the side plate, Figure 4 is a partially cutaway perspective view of the welding equipment, and Figure 5 (+1 and (11)
is a representative point explanatory diagram showing the cross-sectional shape and position of the groove. 0... Origin of coordinate system, l... Lower side plate, 2... Upper side plate, 8... Horizontal joint, 4... Bevel, 5...
Welding torch, 6... slit light, 7... light source, 8.
... Linear image 9 ... Image sensor, lO ... Video screen, 11 ... Arithmetic control unit, 12 ... Image of shape and position captured from the front, 18 ... Video, ■4 ...Servo mechanism, 15...Servo mechanism, 16.17-...Wheel, 18a, 18b, 1B&, 18b...Pulley, 19.19...Flux receiver is belt, machining...
Groove, 21.21'... Frame, 1st port ¥3 Figure Figure 4 Figure 2 Figure 5

Claims (2)

[Claims] (1) A linear image representing the shape of the groove of the material to be welded, obtained by irradiating beam-processed light onto the groove of the material to be welded from a certain distance at a certain angle? , an image captured from an oblique lateral direction by an image sensor held at a constant position and angle with respect to the light source and the workpiece, and each image on the linear image is Detecting all image coordinates of a point, and controlling the aiming position, angle, welding current, and other welding conditions of the welding torch as necessary based on the shape and position of the groove obtained by processing all the coordinates. Automatic welding method with all features. (2) A device for welding horizontal joints of tank side plates, including a welding torch whose position is adjustable, a light source of beam-processed light, and an image sensor disposed at a fixed position diagonally horizontally with respect to the light source; An arithmetic and control unit that receives and processes signals from the image sensor and controls the aiming position and welding conditions of the welding torch, and a welding torch operating mechanism? Installed on a common traveling frame, the soil on the upper tank side plate...wheels from 1? An automatic welding device that is characterized by being lowered through.