JP2564738B2 - Method and apparatus for detecting welding groove shape - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for detecting a shape of a welding groove in groove welding.

[0002]

2. Description of the Related Art As the demand for labor saving and quality improvement through automation of welding work has increased, even if there are irregularities in the shape of the welding groove, the welding equipment and welding torch position etc. are adjusted according to the fluctuations in the welding equipment. However, it has become necessary to automatically perform good welding, and the technology for detecting the shape of the weld groove is an important technical point in achieving this. One technology related to groove shape detection is disclosed in Japanese Examined Patent Publication Sho 59-6157.
No. 4 publication discloses it. In this, as shown in FIG. 8, a vertical distance meter 1 for detecting distance information to the surface of the welding member 31 is arranged above the welding groove, and the vertical distance meter 1 is welded by a pulse motor 8 and a ball screw 10. A transverse drive is performed in a direction perpendicular to the line, and a beam such as a laser emitted from a range finder is directly applied to the groove portion to measure the vertical distance (height) of the butt welding member 31 at each transverse position. The distribution of the detection distance (height) in the horizontal direction indicates the cross-sectional shape of the groove. That is, the method of moving the vertical distance meter 1 in the direction perpendicular to the welding line (longitudinal direction of the groove) in this way to detect the groove shape is as shown in FIG. When detecting the groove shape of the butt welding member 31, the distance (height) information of the welding groove is almost equal to the cross section 32 orthogonal to the welding line direction and the straight line 33 where the welding groove surface and the upper surface of the welding member intersect. Since it is obtained by the whole line (33), it is possible to accurately measure the groove shape at the cross section 32, that is, the groove cross-sectional shape.

[0003]

However, as shown in FIG. 9, the technique for detecting the groove shape as described above is applied to a welding groove when one side member of the groove is a wall-shaped welding member Mv, or When applied to a welding groove having a step as shown in FIG. 10, there are the following problems.

That is, when applied to a welding groove formed by a wall-shaped welding member Mv and a butt welding member Mh,
As shown in FIG. 9, when the vertical distance meter 1 is moved, the vertical distance meter 1
And the wall surface 4 of the wall-shaped welding member Mv interfere with each other, and
The position / shape (depth and width) of the weld groove at part a in the figure cannot be measured. Regarding the collision between the wall surface 4 and the vertical distance meter 1, even if the movement range is set within a range where the vertical distance meter 1 and the wall surface 4 do not collide with each other at the beginning, the wall position may be changed due to the bending of the welding member as the welding progresses. The (horizontal direction) often shifts, which leads to the vertical distance meter 1 colliding with the wall surface 4 and being damaged.

[0005] Further, even in a welding groove having a large step,
When the height of the wall is low in the measurable range of the vertical distance meter 1, it is possible to move the vertical distance meter 1 in a range straddling both sides of the groove as shown in FIG. A rangefinder with a large measuring range is expensive, and since the size and weight are large, the groove detection device increases in size and weight, and the setting property (correct positioning) of the rangefinder during welding is poor. To In terms of measurement accuracy, the wall surface 4
Is inclined, the wall surface 4 side is a wall-shaped welding member M
Since only the position (height) of the upper end face 34 of v can be detected with high accuracy, the groove width estimated from the information of the vertical distance meter 1 has a large error, and the groove shape cannot be measured accurately and accurately. .

[0006] Due to such a problem, when welding the welding member Mv such that the one side member of the groove has a wall shape, a large step, or an inclination, the groove shape has variations (the groove cross-sectional shape in the groove longitudinal direction). Is uneven), the above-mentioned Japanese Patent Publication No. 59-
A conventional groove sensor disclosed in Japanese Patent No. 61574 detects a groove shape (particularly a groove width dimension) and controls welding conditions and a welding torch position to appropriate values based on the detected groove shape to perform welding. Can no longer be performed, and this greatly impedes securing welding quality and efficiency.

An object of the present invention is to accurately measure the shape of a groove formed by a wall-shaped welded member on one side of which the groove shape is difficult to detect as described above over the entire length in the transverse width direction. Do

[0008]

In the present invention, one of the longitudinal distance meters (1) above the welding groove (14) formed of a wall-shaped welding member (Mv) and the other welding member ( Mh) and the vertical distance meter (1)
With the reflection plate (2) between , the horizontal distance (21) from the vertical distance meter (1) to the wall-shaped welding member (Mv ) is detected , and then the vertical distance meter (1) is used to detect the other distance. One welding member (M
The vertical distance (23) to each of a plurality of points in the horizontal direction of v) is detected, and the width and depth of the welding groove are obtained from the horizontal distance (21) and the vertical distance (23) . In addition, in order to make it easier to understand
The reference numerals of the corresponding elements or corresponding matters of the embodiments shown in the drawings and described later are added to the above .

[0009]

[Operation] The signal of the vertical distance meter (1) is caused to travel at a right angle to the groove wall surface (4) through the reflector (2) arranged below the vertical distance meter (1), ), The lateral distances to the groove wall surface (4) at a plurality of locations can be detected, and the position and inclination of the wall surface (4) can be estimated. In particular, the groove wall surface (4) is often a rolled surface of a steel plate, a very good signal is obtained, and estimation with high accuracy and reliability is possible.

From the position / tilt information of the wall surface (4) above,
The latest groove wall surface position on the traverse movement surface of the vertical distance meter (1) outside the reflector (2) (distance of vertical distance meter 1 to wall surface 4)
Since it can be estimated, set the proper traverse movement position and range to traverse the vertical distance meter (1) to the groove wall surface (4),
Avoid interference collision between rangefinder (1) and groove wall surface (4) and surface of butt groove (14) and other welded member (Mh)
The distance information in (6) can be reliably collected.

That is, the vertical distance meter (1) is laterally moved from above the reflecting plate (2) toward the groove wall surface (4), so that the upper surface (6) and slope (5) of the butting material (Mh). Further, the distance information to the groove bottom (7) can be detected, and the groove depth and inclination, that is, the groove cross-sectional shape can be calculated.

[0012]

1 and 2 show an embodiment of an apparatus for carrying out the present invention. In FIG. 1, a support frame supported by an unillustrated welding movement mechanism main body (welding movement base) that can move in a direction perpendicular to the paper surface substantially parallel to the upper surface 6 of the butt welding member Mh via an attitude adjusting mechanism. 13, ball screw 1
0 is rotatably supported. The ball screw 10 is driven in the forward and reverse directions by the pulse motor 8. Ball screw 10
A distance meter support member 11 is screwed to the ball screw 10. When the ball screw 10 is normally rotated by the normal rotation of the pulse motor 8, the support member 11 approaches the wall surface 4 of the wall-shaped welding member Mv (left side). When the ball screw 10 rotates in the reverse direction due to the reverse rotation of the pulse motor 8, the support member 11 moves in the direction away from the wall surface 4 of the wall-shaped welding member Mv (to the right). The vertical distance meter 1 is mounted on the support member 11, and the vertical distance meter 1 detects the distance from the vertical distance meter 1 to the object below it (the butt welding member Mh or the backing member Mr), that is, the height of the object. As the distance meter 1, for example, a semiconductor laser type optical displacement meter is used.

A reflection plate support member 12 is fixed to the support frame 13, and the reflection plate 2 is supported by the support member 12. This reflection plate 2 is 45
In other words, the signal emitted from the vertical distance meter 1 is set in the direction facing the wall surface 4, and the position can be adjusted in the vertical and horizontal directions with screws or the like.

A rotary encoder 9 having a rotation direction detection circuit is connected to the ball screw 10, and the encoder 9 outputs a signal indicating the rotation direction and one for each rotation of the screw 10 at a predetermined small angle. The rotation synchronization pulse of the pulse is given to the counter PC1. The home position sensor (not shown) is at the retracted position on the movement path of the support member 11 (the right end of the movement range: the position indicated by the chain double-dashed line in FIG. 3), and the support member 11
When reaches the retracted position, the home position sensor gives a clear instruction signal to the counter PC1. Counter pc
1 counts up the rotation synchronizing pulse when the rotary encoder 9 gives a signal indicating the forward rotation, and counts up when it gives a signal indicating the reverse rotation.
When the support member 11 is at the retracted position and the count value is cleared (count value = 0) by the clear instruction signal of the home position sensor, the count value of the counter PC1 is determined by the following. Shows how far to the left you are. That is, the count data of the counter PC1 represents the position of the vertical distance meter 1 in the direction crossing the groove.

Incidentally, the vertical distance meter 1 is projected to the left side of the support member 11 so that it can be applied to the V groove shown in FIG. Can move further to the left than the left edge of. The vertical distance meter 1 is supported by the support member 11 via two sets of angle adjusting mechanisms (not shown), and has a rotation angle about an axis parallel to the paper surface and perpendicular to the wall surface 4, and an axis perpendicular to the paper surface. The rotation angle around the center can be adjusted. By these adjustments, the detection direction of the vertical distance meter 1 can be set to be perpendicular to the upper surface 6 of the butt welding member Mh or parallel to the wall surface 4.

Under the above-described structure, the data processing device (computer) DPD mainly including a microprocessor (CPU) measures the groove wall surface measured by the vertical distance meter 1 through the reflecting plate 2. 4 and the vertical distance meter 1 when the vertical distance meter 1 is moved laterally from the retracted position (corresponding to the retracted position of the support member 11) to just before hitting the wall surface 4 in accordance with the horizontal distance information. Distance (height; welding groove depth)
Collect information. That is, the signal of the vertical distance meter 1 is changed to A /
It is taken into the CPU through the interface such as the D converter AD1 and the counter PC1. The horizontal drive of the vertical distance meter 1 is performed by sending a pulse drive signal from the CPU to the motor driver MD1. The position of the reflection plate 2 in the moving range of the vertical distance meter 1 is measured in advance and the CPU
Stored in the memory of.

The position of the welding groove using the apparatus described above
The shape measurement will be described next. First, the ball screw 10 and the vertical distance meter 1 are set at a lateral position where there is a margin from the wall surface 4 with respect to the welding groove 14 having one side, and then the ball screw 10 is substantially perpendicular to the groove wall surface 4. (But welding member M
(not parallel to the upper surface 6 of h), and not shown so that the measurable range (height direction) of the vertical distance meter 1 is sufficiently high to cover the abutting member upper surface 6 and the groove bottom 7. The attitude of the support frame 13 supported by the welding carriage is adjusted (when the upper surface 6 of the butt welding member Mh shown in FIG. 1 is substantially horizontal, the center position of the adjustment range (0 scale).
Thus, the ball screw 10 is horizontal and the support members 11 and 12 are vertical). And by the angle adjustment mechanism of the above rangefinder,
The detection direction of the vertical distance meter 1 is finely adjusted perpendicularly to the upper surface 6 (when the upper surface 6 of the butt welding member Mh shown in FIG. 1 is substantially horizontal, at the center position (0 scale) of the adjustment range, The detection direction of the vertical distance meter 1 is vertical, and the inclination of the reflection plate 2 is 45 degrees with respect to the horizontal).

When the upper surface 6 of the butt welding member Mh is substantially horizontal, the posture of the support frame is adjusted to the center position (0
It is a standard that the angle adjustment of the rangefinder 1 is the center position (0 scale) of the adjustment range, and the operator is required to adjust these values to values different from 0. Inputs an adjustment value to the data processing device DPD from the operation board.

The data processing device DPD measures and calculates the groove shape as follows. First, the support member 11 is
Position (the position indicated by the chain double-dashed line in Fig. 3). At this time, the visual field of the vertical distance meter 1 is on the reflection plate 2. The data processing device DPD reads the measurement data of the vertical distance meter 1 while driving the vertical distance meter 1 to the right from there, and stores it in correspondence with the count data of the counter PC1 and stores the measurement data. The amount of change is calculated, and the right drive is temporarily stopped when the amount of change in the measured data changes significantly (where the visual field of the vertical distance meter 1 deviates from the reflector 2 and faces the upper surface 6 of the butt welding member Mh). To do. FIG. 4 shows the measurement data group 21 (I) of the vertical distance meter 1 obtained before the suspension. These data 21 represent the lateral distance of the wall surface 4 through the reflection plate 2. De-
The data processing device DPD uses the method of least squares to find the linear equation (the linear equation representing the wall surface 4) represented by the data 21 and stores the linear equation, and the height position of the vertical distance meter 1 is also stored. Then, the lateral distance from the home position to the wall surface 4 is calculated, and the left limit position of the vertical distance meter 1 is calculated from the calculated value and stored.

Next, the data processing device DPD starts driving the vertical distance meter 1 to the left again, and the count value of the pulse counter PC1 (horizontal position of the vertical distance meter 1) is calculated to the left limit position. The vertical distance meter 1 is driven to the left until it becomes, and the left drive is stopped at the left limit position. During the period from the start to the stop of this left drive, the data processing device DPD is
The measurement value of the vertical distance meter 1 is read for each minute movement of and the memory is stored in correspondence with the count data of the counter PC1. A measurement data group 23 during this period is shown in FIG. After stopping the left drive, the vertical distance meter 1 returns to the right limit position, that is, the home position.

The data processing unit DPD then calculates the lateral deviation of the measured data group 23 and switches the deviation (see FIG. 6).
D, C) of the butt-welding member Mh, and the measurement data group 23 is connected to the group corresponding to the upper surface 6 of the butt-welding member Mh.
Is divided into a group corresponding to the slope 5 and a group corresponding to the upper surface 7 of the backing material Mr, and three linear equations represented by the data of each of these groups using the method of least squares ( Top 6
Is calculated, and a linear expression representing the slope 5 and a linear expression representing the groove bottom surface 7) is obtained and stored. Then, as shown in FIG. 6, the trapezoidal corners A, B, which represent the groove cross section, are calculated from the linear equation representing the wall surface 4 and the three linear equations previously calculated and stored in the memory. Calculate C and D. The above is the measurement of the groove shape in which the vertical distance meter 1 is placed at a position in the longitudinal direction of the welding groove 14 (direction perpendicular to the paper surface of FIG. 1).

The supporting frame 13 supported by the welding carriage and the above-mentioned distance measuring equipment mounted thereon are continuously connected to the welding carriage at a low speed in the longitudinal direction of the welding groove 14 (direction perpendicular to the plane of FIG. 1). While moving, or repeatedly moving and stopping a predetermined distance, the welding groove 14 is performed over substantially the entire length in the longitudinal direction.

[0023]

The present invention has the following effects.

(1) The welding groove position / shape (width / depth dimension) can be efficiently and accurately measured with respect to a welding groove having a one-wall shape or a large step, especially a wall surface having a reverse inclination.

(2) By realizing the groove sensor of the present invention,
It becomes possible to input accurate groove position and shape information to the automatic welding system that controls welding conditions and welding torch position during welding progress, especially for welding work with workpieces with variations in groove shape. It becomes possible to efficiently deal with high quality.

As described above, the practical effect is very large.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an apparatus for implementing the present invention.

FIG. 2 is a side view of the distance measuring mechanism 35 shown in FIG.

3 is a front view of the distance measuring mechanism 35 shown in FIG.

FIG. 4 is a graph showing distance information obtained through the reflection plate 2 in the vertical distance meter 1 shown in FIG.

5 is a graph showing distance information of a butt groove portion obtained by the vertical distance meter 1 shown in FIG.

6 is a graph showing groove cross-sectional shapes A to C obtained from the information shown in FIGS. 4 and 5. FIG.

FIG. 7 is a perspective view of a welding member having a groove shape of one side wall surface, (a) shows a case where the wall-shaped welding member is cylindrical and the butt welding member is a flange material, and (b) shows a wall-shaped member. The case where both the welded member and the butt welded member are steel plates is shown.

FIG. 8 is a perspective view showing a conventional V-groove shape detection mode.

FIG. 9 is a transverse cross-sectional view when a conventional groove shape measurement is applied to a single wall groove.

FIG. 10 is a transverse cross-sectional view when the groove shape measurement of the sub-opening is applied to a groove having a large step.

[Explanation of symbols]

1: Vertical distance meter 2: Reflector 4: Wall groove 5: Butt side groove surface 6: Butt side member upper surface 7: Groove bottom surface 8: Motor 9: Encoder 10: Ball screw 11: Vertical distance meter support member 12 : Reflector support member 13: Groove sensor support member 14: Welding groove 21: Lateral distance detection information 22: Conversion information of 21 23: Detection information of the vertical distance meter 1 31: Welding member 32: Right angle to welding direction Cross section 33: Straight line where the cross section of 32 and welding groove intersect 34: Groove wall upper surface 35: Moving mechanism main body

Claims (3)

(57) [Claims] A vertical distance meter above the weld groove to claim 1 wherein one is a wall-like welding member by a reflector between the other welding element and said longitudinal distance meter, wherein the longitudinal distance meter Detecting the lateral distance of the wall-shaped welding member, and then measuring the other welding member by the longitudinal distance meter .
A method for detecting a welding groove shape, in which a vertical distance to each of a plurality of lateral directions is detected, and a width and a depth of the welding groove are obtained from the horizontal distance and the vertical distance. 2. The welding groove shape detecting method according to claim 1, wherein the lateral distance is detected at a plurality of points in the vertical direction of the wall-shaped welding member, and the inclination of the wall surface is obtained from these lateral distances. 3. A longitudinal distance meter, one of which is disposed above a welding groove formed of a wall-shaped welding member; and is arranged between the other welding member forming the welding groove and the longitudinal distance meter. A reflector plate that is provided and faces the wall-shaped welding member; a traverse drive mechanism that drives the vertical distance meter in a direction that crosses the welding groove between the reflection plate and the wall-shaped welding member; and The vertical distance meter calculates the horizontal distance between the vertical distance meter and the wall-shaped welding member from the measurement value of the vertical distance meter when the vertical distance meter is above the reflecting plate, and the horizontal distance and the vertical distance meter are A welding groove shape including a data processing device that generates transverse cross-section information of the welding groove from the measured value of the longitudinal distance meter when the reflecting plate is separated between the reflecting plate and the wall-shaped welding member. Detection device.