JPH0647540A - Method and device for detecting welding groove shape - Google Patents

Abstract

PURPOSE:To efficiently and accurately measure the groove position and shape by disposing a horizontal range finder and a vertical range finder above a welding groove and oscillating and moving both range finders. CONSTITUTION:The vertical range finder 1 is arranged in the square direction to the different surface in level of the groove and moved sidewise in the orthogonal direction to the different surface in level. In addition, the horizontal range finder 2 is arranged in the direction in opposition vertically to the different surface in level and moved vertically. A data processor DPD collects bits of information 7 and 8 of distance signals of the vertical range finder 1 and the horizontal range finder 2 at specified pitches via A/D converters AD1 and AD2. The position in the horizontal direction of the groove one side wall surface and the height position and difference in level of the groove upper surface are detected from these bits of information. Since the height and position in the horizontal direction of welding members are detected independently by the vertical movement of the horizontal range finder 2, a function as a profile sensor of the welding groove with high accuracy under noncontact can be displayed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding groove shape detecting method and apparatus 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 conditions and welding torch position, etc. can be adjusted according to the fluctuations in the welding equipment. It has become necessary to adjust and automatically perform good welding, and the technology for detecting the shape of the weld groove is an important technical point in achieving this.
A groove shape detecting device is disclosed in Japanese Patent Publication No. 59-61574. As shown in FIG. 10, the vertical distance meter 1 for detecting the distance to the surface of the welding member 31 is arranged above the welding groove, and the distance meter 1 is connected to the welding line by the pulse motor 9 and the ball screw 11. For the longitudinal direction of the groove,
The groove is traversed, and the groove is directly irradiated with a beam of a laser or the like emitted from the longitudinal distance meter 1 to measure the shape of the groove.

As described above, the method of driving the longitudinal distance meter 1 in the direction traversing the groove to detect the groove shape, that is, the groove cross-sectional shape is as shown in FIG. When the groove shape of the member 31 is detected, the distance from the longitudinal distance meter 1 is measured with respect to the cross section 32 perpendicular to the welding line direction (longitudinal direction of the groove) and the straight line 33 at which the welding groove surface and the upper surface of the welding member intersect. Since the information is surely obtained on almost the entire line 33, the groove shape at the cross section 32 can be accurately measured.

[0004]

When the above-mentioned conventional groove shape detection technique is applied to a weld groove formed by a welded member having variations in shape and size or a welded member having a rough surface. There are the following problems. In general, an optical displacement sensor, which has a long length and is compact, is used as the sensor for the vertical distance meter 1 in many cases. This optical displacement sensor, as shown in FIG.
This is a mechanism in which light emitted from a semiconductor laser is applied to an object, the diffused reflected light is condensed by a lens, and the distance is detected by the principle of trigonometry using a light receiving element PSD. However, the welding member actually targeted is rarely a rolled surface with uniform light reflection characteristics. The optical rangefinder is
The measurement accuracy tends to cause an error depending on the properties and color of the measurement surface. In particular, when the target is in a state close to a mirror surface, proper diffuse reflection light cannot be obtained, and the distance to the surface cannot be detected in many cases. For example, when the periphery of the groove has a mirror-like light selection and a polygonal shape due to a gliding process for repairing a scratch or the like, the light is reflected in a direction away from the light receiving element PSD, and If the surface is roughened by scales or rusted by QT treatment such as water quenching for high strength specifications,
Light reflected by the light receiving element PSD is small. Therefore, according to the conventional technique, even if the optical rangefinder is traversed above the welding groove for such a welding groove whose surface quality is not sufficiently good, proper reflected light cannot be obtained, and therefore detection is performed. The reliability of the prepared groove shape data is reduced.

For example, as shown in FIG. 5, in the grinder processing unit Gr, the detection data is interrupted, and in the scale or rust-attached portion, the detected data has a variation error. When the groove shape is estimated based on only this information, there is a problem that it is difficult to achieve sufficiently reliable detection of the position and shape of the welding groove.

[0006] Due to such a problem, when there are variations in the properties of the groove surface during welding, the groove shape (especially the width dimension) is detected by the groove sensor, and the welding conditions and welding torch position are determined based on this. It will not be possible to control the welding to an appropriate value and carry out the welding process, which will greatly hinder the welding quality and efficiency. In particular, when the inclination angle of the groove surface is large, for example, when it is a wall-shaped surface of about 90 degrees, the correct shape (inclination angle or depth direction) of the groove surface (wall-shaped surface) by the vertical distance meter 1 is used. It is difficult to measure the position in the lateral direction.

The first object of the present invention is to improve the reliability of the groove shape measurement, and the second object is to realize the highly reliable measurement when the inclination angle is large (around 90 degrees). And

[0008]

According to the present invention, a horizontal distance meter (2) disposed above an opposing welding member (Mv, Mh) forming a welding groove is moved in parallel in the welding depth direction to open it. A vertical distance meter installed above the groove by obtaining information on the upper surface position of both welding members (Mv, Mh) forming the tip and the position of the wall surface of the step portion in the welding depth direction.
The position information of the groove cross section is obtained by traversing (1) in the direction transverse to the longitudinal direction of the groove, and the position information of the wall surface of the step portion in the welding depth direction obtained by the horizontal distance meter (2) and the vertical direction. The width and depth of the groove surface are measured based on the groove cross-section position information at each lateral position obtained by the distance meter (1). The symbols in parentheses indicate the corresponding elements of one embodiment of the apparatus for carrying out the present invention shown in the drawings.

[0009]

FIG. 7 shows an object having a wall-shaped groove surface as an example. In this example, there is a step between the welding members facing each other.
When the vertical distance meter 1 is arranged in a direction parallel to the step surface, that is, the wall surface and is moved laterally in the direction perpendicular to the step surface, the object shape as shown by the plot line (broken line) as shown in FIG. Get information about. In this case, the height direction position of the object is the distance information to the object detected by the vertical distance meter 1, and the detection information is affected by an error or the like depending on the surface texture of the object, but there is a step. The lateral position is the information of a position meter such as an encoder, and the position where the information detected by the vertical distance meter 1 changes greatly is determined. Therefore, the wall-shaped groove surface is vertical (to the wall-shaped groove surface). When the detection direction of the vertical distance meter 1 is parallel), the object can be accurately detected with almost no influence of the surface texture of the object. But,
When the wall-shaped groove surface is deviated from the vertical, the detection value there is largely varied or the measurement becomes impossible.

Next, as shown in FIG. 8, a lateral distance meter 2 is arranged in a direction facing a step surface perpendicularly or substantially perpendicularly to an object similar to the above, and is parallel or substantially parallel to the step surface. When moved up and down, information about the object shape shown by the plot line (broken line) as shown in FIG. 8 is obtained. In this case, contrary to the above (FIG. 7), the lateral position where the step exists is obtained by the distance information detected by the lateral distance meter 2, and the position in the height direction of the object corresponds to the information of the position meter such as an encoder. Become.
In other words, by determining the position where the distance information detected by the rangefinder changes greatly (the upper surface of the welded member with the wall surface and the groove bottom), the object that was not highly reliable by the conventional detection method, especially the vertical front-back direction. It is possible to detect the position in the height direction of the welded member having the wall surface with high accuracy with almost no influence of the surface texture. Further, in the L-shaped welding groove, the groove surface on one side is often the rolling surface of the steel machine, and the reflection performance of distance information such as light is very good. Position information can also be detected with high accuracy.

In the present invention, the information necessary for the groove shape calculation is collected in both the embodiment shown in FIG. 7 and the embodiment shown in FIG. 8, and the portion which cannot be obtained or is unreliable in one embodiment is identified in the other embodiment. Since the entire shape of the groove cross section is obtained by supplementing it with the highly reliable data obtained in step 1, highly reliable groove shape data can be obtained.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

[0013]

1 to 4 show an embodiment of an apparatus for carrying out the present invention in one mode. The present invention is particularly effective for an L-shaped groove or the like in which one side wall surface is a rolled surface of steel material, so an application example of the groove will be described. This kind of welding groove is shown in FIG.
It is used in many places as shown in (a) to (e).

In FIG. 1, the longitudinal direction of the weld groove (see FIG.
(Not shown in the drawing) and a measuring mechanism support frame WBs2 mounted via a posture adjusting mechanism on a welding moving base (not shown) which is movable, and a ball screw 11v extending horizontally and a ball screw extending vertically. A screw 11h is rotatably supported. Guide bars 12v and 12h are arranged in parallel with the ball screws 11v and 11h and fixed to the support frame WBs. Distance measuring carriages 13v, 13h are ball screws 11
It is screwed to v, 11h and is guided automatically by guide bars 12v, 12h in the direction in which they extend.

The carriage 13v can be angle-adjusted through a two-axis angle adjusting mechanism (not shown) about an axis perpendicular to the paper surface (FIG. 1) and about an axis orthogonal to the vertical axis and parallel to the paper surface. The vertical distance meter 1 is attached to the. The carriage 13h is provided with a two-axis angle adjusting mechanism (not shown) so that the angle can be adjusted freely about the axis perpendicular to the paper surface (FIG. 1) and about the axis orthogonal to the vertical axis and parallel to the paper surface. Distance meter 2 is attached.

The ball screw 11v is a pulse motor 9v,
The ball screw 11h is driven in the forward and reverse directions by the pulse motor 9h. The rotary shafts of the pulse motors 9v and 9h are respectively coupled to the rotary encoders 10v and 10h, which are speed-synchronized pulses of one pulse for each rotation of the ball screws 11v and 11h by a predetermined small angle. When,
A direction signal representing the direction of rotation (forward or reverse) is generated and given to the pulse counters PC1 and PC2.

Although not shown, there is a limit switch (home position sensor) that closes when the carriage 13v reaches the right limit position (retracted position = home position), and a signal (home) indicating this switch is closed. The m-position signal) is given to the counter PC1 as a clear signal. The counter PC1 is in a clear state while the home position signal is present (count output indicating a count value = 0).
When there is no home position signal, the forward rotation signal arrives (carriage 13v moves to the left), the speed synchronization pulse is counted up, and the reverse rotation signal arrives (carriage 13v moves to the right). Sometimes the speed sync pulse is counted down. Therefore, the counter P
The count output of C1 indicates how far the carriage 13v (longitudinal distance meter 1) is moving leftward from the home position (right limit position) (horizontal distance). This count output is given to the data processing device DPD.

Similarly, although not shown, the carriage 1
There is a limit switch (home position sensor) that closes when 3h reaches the upper limit position (retracted position = home position), and a signal indicating the closing of this switch (home position signal) is used as a clear signal on the counter PC2. Given to. The counter PC2 is in a clear state (count output indicating a count value = 0) while there is a home position signal, and when there is no home position signal,
When the forward rotation signal arrives (the carriage 13h moves downward), the speed synchronization pulse is counted up, and when the reverse rotation signal arrives (the carriage 13h moves upward), the speed synchronization pulse is counted down. Therefore, the count output of the counter PC2 represents how far the carriage 13h (horizontal distance meter 2) is moving from the home position (upper limit position) (depth direction distance). This count output is given to the data processing device DPD.

The setting of the measuring mechanism FMD shown in FIG. 1 is performed as follows. First, the support frame W is attached to the welding carriage.
Adjust the mechanism that adjusts the posture of Bs to adjust the groove width direction (Fig. 1
The horizontal movement direction of the vertical distance meter 1 (the direction in which the ball screw 11v extends) becomes parallel, and the range of the groove width is covered by the horizontal movement range, and the groove depth direction (Fig. 1 up and down) and horizontal distance meter 2 up and down movement direction (ball screw 1
The direction in which 1h extends) becomes parallel, and the vertical movement range is set up to cover the upper end of the butt groove. Next, an operation board (not shown) is operated to operate the data processing device D.
The carriages 13v and 13h are driven via the PD to set them (necessarily the vertical and horizontal distance meters 1 and 2) to the home position. Before and after this, a biaxial angle adjustment mechanism
Adjust the angles of the horizontal distance meters 1 and 2.

The data processing device DPD sets the pulse motors 9v and 9h vertically and horizontally through the motor drivers MD1 and MD2, and the home position of the horizontal distance meters 1 and 2 (right limit position,
Forward rotation is performed at a constant speed from the upper limit position), and the distance signals of the vertical and horizontal distance meters 1 and 2 are fed at a constant pitch to the A / D converter AD.
1, collect via AD2. As a result, the data processing device DPD obtains the position information as shown in FIG. 3 from the horizontal distance meter 2 and the position information as shown in FIG. 4 from the vertical distance meter 1. From this information, the data processing device DP
D detects the lateral position of the side wall surface of the groove, the height position of the groove upper surface, and the step.

That is, the position information of the horizontal distance meter 2 (black circles in FIG. 3) is subjected to histogram processing in the groove width direction (distance detection direction) (projection of data measurement points (black circles) in FIG. 3 onto the horizontal axis). Calculation of the measurement point distribution density) is performed, and the area with the high measurement point distribution density obtained by this is determined as the position of the wall surface.
The position information of the horizontal distance meter 2 (black circles in FIG. 3) is processed in the groove depth direction (distance meter 2 driving direction) by histograph processing (data in FIG. 3).
Calculation of the measurement point distribution density by projecting the measurement points (black circles) onto the vertical axis, and the obtained measurement point distribution density is high in two areas (Mv upper surface corresponding position and Mh upper surface corresponding position 2).
Location) is determined as the upper surface position of the welding members Mv, Mh.
Similarly, the position of the wall surface and the upper surface positions of the welding members Mv and Mh are determined by the histogram processing of the position information (dotted line in FIG. 4) of the vertical distance meter 1. Furthermore, the horizontal distance meter 2
By calibrating the position information (FIG. 3) obtained in step 1 to the vertical and horizontal axis values of the position information obtained by the vertical rangefinder 1 shown in FIG. 4, and superimposing it on the position information obtained by the vertical rangefinder 1, From the distribution of each information of the information group in the two-axis coordinate system (Fig. 4), an information group in which the area not obtained by one distance meter is supplemented by the detection information of the other distance meter is generated. , The upper surfaces of the welding members Mv and Mh, the groove surfaces of both members, and the groove bottom are calculated to obtain a welding groove shape (width at each depth position).

As described above, the groove shape information can be obtained from the above-mentioned two kinds of sensing for the weld groove, and among the welding groove shape information, the upper surface height position position on the groove side of FIG. , Side lateral position a on one side of the groove, and height position c on the other side of the groove can be detected as common overlapping data, and it is checked by checking whether those data are different from each other and matching is performed. By doing so, a more reliable groove shape detection can be achieved.

Further, in the present invention, the vertical and horizontal movements of the horizontal distance meter 2 alone detect the height and the lateral position of the welding member Mv (the wall surface of the welding member Mv). Can also function as.

[0024]

The present invention has the following effects.

(1) Even if the surface texture of the weld groove is not sufficiently good, the weld groove position / shape (width / depth dimension) can be measured efficiently and accurately.

(2) The realization of the present invention makes it possible to input accurate groove position / shape information to an automatic welding system which controls welding conditions and welding torch positions while welding is in progress. It becomes possible to efficiently perform high-quality welding work on a workpiece having variations in tip shape.

As described above, the practical effect is very large.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating an example of an apparatus that implements the present invention in one aspect.

FIG. 2 is a cross-sectional view showing an outline of the groove 3 shown in FIG.

FIG. 3 is a graph showing position information obtained by the lateral distance meter 2 shown in FIG.

FIG. 4 is a graph showing position information obtained by the vertical distance meter 1 shown in FIG.

FIG. 5 is a cross-sectional view of a welded member having grinder grinding and scale rust, and a graph showing the measurement data of the weld groove shown therein by a longitudinal distance meter.

FIG. 6 is a cross-sectional view of a welded member having a good surface texture, and a measurement data of a weld groove shown therein by a longitudinal distance meter.
It is a graph which shows the data.

7A and 7B are a cross-sectional view showing a mode of detecting a step portion shape by a vertical distance meter, and a graph showing detection data.

8A and 8B are a cross-sectional view showing a mode of detecting a stepped portion shape by a horizontal distance meter, and a graph showing detection data.

FIG. 9 is a drawing showing various welding members forming an L-shaped welding groove, in which (a), (b), (c) and (d) are perspective views, and (e-1 / 2) is a front view. , (E-2 / 2) is a side view.

FIG. 10 is a perspective view showing the external appearance of a welding groove measuring device in Itarai.

11 is an enlarged front view showing some of the components of the vertical distance meter 1 shown in FIG. 10 and a measurement target surface (cross section).

FIG. 12 is an enlarged front view showing some of the components of the vertical distance meter 1 shown in FIG. 10 and a measurement target surface (cross section).

13 is an enlarged front view showing some of the constituent elements of the vertical distance meter 1 shown in FIG. 10 and a measurement target surface (cross section).

[Explanation of symbols]

WBs: Support frame mounted on welding carriage 1: Vertical distance meter 2: Horizontal distance meter 3: Weld groove Mv, Mh: Welding member Mr: Backing member 4: Weld groove upper surface 5: Weld groove side surface ( Wall surface 6: Weld groove side surface 7: Weld groove top surface 8: Groove bottom surface 9: Pulse motor 10: Encoder 11v, 11h: Ball screw 12v, 12h:
Guide bar 13v, 13h: Supporting member of distance measuring carriage 31: Welding member 32: Cross section perpendicular to welding direction 33: Straight line where cross section of 32 and welding groove FMD: Measuring mechanism DPD: Data processing device

Claims (2)

[Claims] 1. A horizontal distance meter disposed above an opposed welding member forming a welding groove is translated in the welding depth direction, and upper surface positions of both welding members forming the groove and a step in the welding depth direction. The position information of the wall surface of the part was obtained, and the longitudinal distance meter arranged above the groove was made to traverse in the direction transverse to the longitudinal direction of the groove to obtain position information of the groove cross section, which was obtained by the lateral distance meter. Welding between opposing welding members, which measures the width and depth of the groove surface by the position information of the wall surface of the step portion in the welding depth direction and the groove cross-section position information of each position in the horizontal direction obtained by the vertical distance meter. How to detect the groove shape. 2. A lateral distance meter movably provided in a depth direction of the groove on a welding moving table that moves in the longitudinal direction of the welding groove between the opposed welding members, and the groove on the welding moving table. Of the longitudinal distance meter provided transversely in the direction transverse to the longitudinal direction, and the position information of the wall surface of the welding depth direction step portion obtained by the lateral distance meter and the lateral direction positions obtained by the longitudinal distance meter. Welding between opposed welding members, including information processing means for reading groove cross-section position information and calculating parameters for defining a welding groove shape between opposing surfaces between opposed welding members based on these information A groove shape detector.