JPH07299702A - Processing work line detector of robot - Google Patents

Abstract

PURPOSE:To provide a processing line detector used for a robot which makes processing work by moving the tip of a tool mounted on the tip of an arm along a processing line CONSTITUTION:A detector 3 is required to receive no influence of any by- product produced during a welding process during, for example, a welding processing work and it is so constituted as being mounted on a tool tip 2a at the time of detection and demounted at the time of processing thus, mountably/demountably. Also, it is provided with such a function as correcting a processing work line detected by the detector according to the data for showing the mounting positions of the processing work and the tool respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a robot for performing a predetermined machining operation by moving the tip of a tool attached to the tip of an arm along the machining operation line, and more particularly to a detection device for detecting the machining operation line. Regarding

[0002]

2. Description of the Related Art In an arc welding robot, welding work is performed by moving the tip of a welding torch attached to the tip of an arm along a welding line.

In this case, a sensor for detecting the above-mentioned welding line is attached to the tip of the robot arm in order to cope with the installation error and variation of the work, and the sensor is positioned on the welding line before the welding work to sense the welding line. A method is available in which detection data on the position and shape of the welding line is acquired, and errors in the data on the torch position and trajectory obtained by teaching are corrected based on the detection data, and then welding is performed.

When the sensor is mounted on the robot as described above, the mounting position of the sensor is the detection range of the sensor,
Considering the range of motion of the robot, it is desirable to place it near the torch at the tip of the robot arm. However, during welding, the sensor may be damaged by heat, spatter, fumes, etc., and it is necessary to separate the sensor from the welded portion in order to protect the sensor.

As a conventional technique of this kind, there is one disclosed in, for example, Japanese Patent Laid-Open No. 3-8582. In this publication, a welding torch is rotatably arranged on a robot, and a sensor for detecting a direction forming a predetermined angle with respect to the longitudinal direction of the torch is attached to a shaft supporting portion of the torch. It is said that the sensor rotates the welding torch so as to detect the lower welding line, and at the time of welding, the welding torch welds the lower welding line and rotates and retracts the welding torch so that the sensor is separated from the workpiece. The technology is disclosed.

Further, in Japanese Patent Publication No. 59-47631, a connector for attaching and detaching a welding line sensor and a welding torch is provided at the tip of a robot arm, and the welding torch is detached from the connector before welding. A technique is also disclosed in which the welding line sensor is attached to the connector, and at the time of welding, the welding line sensor is detached from the connector and the welding torch is attached to the connector.

A laser displacement meter may be used as the welding line sensor for detecting the welding line.

The laser displacement meter detects the distance (displacement) between the robot displacement position of the laser displacement sensor and the welding line. The position of each robot axis at the time of detecting this distance and the robot displacement position of the laser displacement sensor. Based on and, the irradiation position of the laser beam in the robot coordinate system, that is, the position of the welding line can also be detected.

[0009]

According to the techniques described in the above publications, during welding, the welding line sensor is separated from the object to be welded by the rotational drive or the attachment / detachment work, which protects the sensor. It has achieved its intended purpose of being achieved. . However, the above-mentioned Japanese Patent Laid-Open No. 3-858
The technique disclosed in Japanese Patent No. 2 has a problem that the detection range of the sensor is small with respect to the movement of the robot, because the welding line sensor is not provided at the tip of the welding torch, but at the tip of the welding torch.

Further, since the welding torch is rotated so as to be detected by the welding line sensor, the rotated welding torch may interfere with other peripheral devices and objects to be welded. Further, since the welding torch provided with the welding line sensor is rotatably attached to the robot, it is necessary to develop a dedicated robot, which results in cost increase.

On the other hand, in the technique disclosed in Japanese Patent Publication No. 59-47631, the welding torch needs to be attached and detached in addition to the attachment and detachment of the welding line sensor. There is a problem.

When the welding torch is attached and detached, the welding wire and the feed mechanism for the welding gas, cooling water and the like must be attached and detached together. Therefore, the connector
A strict sealing function such as the above-mentioned feeding mechanism is required, and it is also necessary to provide a highly accurate positioning mechanism. Therefore, it is obvious that the structure of the connector is complicated and the cost is high.

The present invention has been made in view of these circumstances, and makes it possible to easily attach and detach only the detection device for detecting a welding line from the tip of the tool without removing the tool such as the welding torch from the robot. The first object is to expand the detection range of the detection device, eliminate interference with other members, improve work efficiency, and reduce cost.

When a laser displacement meter or the like is used as the welding line sensor as described above, the position of the welding line can be accurately determined by the fact that the sensor is mounted on the robot at a predetermined mounting position without displacement. It is a prerequisite for detection.

However, when the welding line sensor is mounted so as to deviate from the mounting position, the optical axis of the laser beam deviates, which causes an error in the position of the detected welding line.

Therefore, conventionally, an adjusting device for adjusting the mounting position (orientation) of the welding line sensor on the robot is provided, and a reference mark such as a cross shape whose position on the robot coordinate system is known is provided on the laser beam irradiation surface. To adjust the mounting position deviation of the welding line sensor by the adjusting device so that the welding line detection position detected when the reference mark is irradiated with the laser beam matches the position of the reference mark. I was doing.

However, such an adjusting method requires the operator to finely adjust the adjusting device while visually observing that the reference mark is irradiated with the laser beam, which is very time-consuming and troublesome. In addition, the adjustment error was large. Further, it is a dangerous work since it is necessary to directly observe the laser beam. Further, since the adjusting device is required, the cost is high.

The present invention has been made in view of such an actual situation, and it is possible to detect a detection error caused by a mounting deviation of a detection device mounted on a robot efficiently without being accompanied by dangerous work. A second object is to enable accurate correction at low cost.

[0019]

Therefore, the first aspect of the present invention
The invention is applied to a robot that performs a predetermined machining operation by moving the tip of a tool attached to the arm tip along a machining operation line, and a robot machining operation that detects the machining operation line before the machining operation. In the line detection device, the detection device is configured to be attachable to and detachable from the tool.

According to a second aspect of the present invention, the first aspect
In addition to the configuration of the invention, the detection device is mounted on the tool, and the processing work line detected by the detection device is corrected based on a detection signal when the reference processing work line is detected by the detection device. I am trying.

[0021]

According to the structure of the first invention, as shown in FIG. 1, the detecting device 3 is detachably attached to the tool 2a. As described above, since only the detection device 3 is detachably attached to the tool without the work of removing the tool 2a itself from the robot 1, it is possible to improve the work efficiency and reduce the cost. In addition, the detection device 3 is attached to the tool 2a.
Can be attached, the detection range of the detection device 3 is expanded, and the tool 2a does not interfere with other members during detection.

According to the second aspect of the invention, the detecting device 3 is mounted on the tool 2a, and the detecting device 3 detects the reference machining line PE based on the detection signal Zi. Processing work line PM detected by 3
Is corrected to PE. In this way, the detection signal Zi of the detection device 3 is automatically corrected and the mounting position deviation adjustment device of the detection device 3 is not required, so that work efficiency is improved, work is performed safely, and cost is reduced. , The accuracy of correction is improved.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a robot working line detecting apparatus according to the present invention will be described below with reference to the drawings.

In this embodiment, as the robot,
We assume a welding robot that performs arc welding work,
Without being limited to this, as long as it is a robot that performs a machining work along a predetermined machining work line, it can be applied to another robot such as a robot for a sealing work.

Further, in the embodiment, it is assumed that a laser displacement sensor is used as a sensor for detecting a welding line, but the welding line sensor is optional as long as it can detect a welding line. A sensor or an ultrasonic displacement sensor may be used.

FIG. 1 is a block diagram showing the configuration of the robot system of the embodiment.

As shown in FIG. 1, the welding robot 1 is
The robot is a multi-joint robot, and a wrist 1b is rotatably provided on a tip arm 1a thereof, and a welding torch 2 is rotatably provided on a tip of the wrist 1b. The welding torch 2 has a shaft 2a at its tip, and the tip 2b is moved along a welding line 21 of a workpiece (hereinafter referred to as a work) 20 to perform welding work.

The position and shape of the welding line 21 are previously detected by the laser displacement sensor 4 before welding work. The sensor 4 constitutes a part of the sensor unit 3 shown in FIG. 2 described later.

The turning base 1c of the robot 1 is provided with a detachable base 5 (described later) on which the sensor unit 3 is placed and locked. The detachable base 5 is within the operation range of the robot 1.

The detection signal S1 of the displacement sensor 4 is applied to the sensor amplifier 16 and input to the sensor controller 18 via the A / D converter 17. As will be described later, the sensor controller 18 generates data indicating the position and shape of the welding line 21 based on the input detection signal S1,
This is added to the robot controller 19.

The robot controller 19 corrects the teaching data of the welding line 21 based on the position and shape data input from the sensor controller 18 and outputs a drive control signal S2 to the robot 1 to drive each axis of the robot. Control. The drive control is performed by using the drive position signal S'2 output from the drive source of each axis of the robot as a feedback signal.

The robot controller 19 also outputs a drive control signal S3 for controlling the drive of the air cylinder 14 (FIG. 2) on the attachment / detachment base 5, as described later.

FIG. 2 is a view showing the construction of a mounting / demounting device for mounting the sensor unit 3 on the torch 2 and for mounting and dismounting the sensor unit 3 on the torch 2, and is a view of FIG. 1 seen from above. FIG. 3 is a sectional view taken along line CC of FIG.

As shown in these figures, the sensor unit 3
Is screwed so that the displacement sensor 4 and the gripper 6 are integrated with each other, and the attaching / detaching device includes the attaching / detaching base 5,
The sensor unit 3 is arranged on the upper surface of the detachable base 5.
Stoppers 12 and 13 for locking the air cylinder 1, an air cylinder 14 arranged on the upper surface of the detachable base 5, and the air cylinder 1
4 and a robot controller 19 for inputting a drive control signal S3.

A signal line 4a for the detection signal S1 is connected to the displacement sensor 4 of the sensor unit 3, and the other end of the signal line 4a is connected to the sensor amplifier 16.

The gripper 6 of the sensor unit 3 has a structure in which a pair of members 7 and 8 are rotatable by a pin 9 (see FIG. 3), and includes an arm portion 6a and a grip portion 6b.

The grip portion 6b is a portion that clamps the shaft 2a of the welding torch 2, and the opening portion 6 into which the shaft 2a can be inserted.
c is formed. An elastic body (for example, rubber) is attached to the inner periphery of the opening 6c to cushion the shaft 2a.

On the other hand, the arm portion 6a is a portion for changing the size of the opening portion 6c by opening and closing the gripper 6 according to the acting force.

Now, when the rod 15 of the air cylinder 14 is in a retracted state and no external force is applied to the arm portion 6a, the spring 10 interposed between the members 7 and 8 is used. The tip end of the arm portion 6a is brought into contact with the stoppers 12 and 13 due to the elastic force of the sensor unit 3 and the entire sensor unit 3 is locked by the stoppers 12 and 13.

However, the rod 15 of the air cylinder 14 is extended and brought into contact with the arm portion 6a, so that the air cylinder 1
When the driving force of No. 4 acts on the arm portion 6a, the driving force overcomes the elastic force of the spring 10, the gripper 6 is opened, and the opening portion 6c is maximized. Therefore,
In this state, the shaft 2a of the welding torch 2 can be loosely inserted in the opening 6c.

The contents of processing performed by the robot controller 19 and the sensor controller 18 in such a configuration will be described with reference to the flowchart of FIG.

First, the drive control signal S2 is output to the drive source of each axis of the robot, and the welding torch 2 is indicated by the arrow A in FIG.
The torch tip 2b is moved as shown in FIG.
The gripper 6 of the sensor unit 3 which is locked above is positioned above the gripping portion 6b (step 101).

When the feedback signal S'2 from each axis of the robot is detected that the above positioning is performed, the controller 19 outputs the drive control signal S3 to the air cylinder 14 to extend the rod 15. The gripper 6 is opened to make the opening 6c the maximum size. Next, the drive control signal S2 is output to each axis of the robot, and the shaft 2a of the welding torch 2 is inserted into the opening 6c to a predetermined position. Next, when it is detected by the feedback signal S'2 that the vehicle is positioned at the predetermined position, the drive control signal S3 is output to the air cylinder 7 and the rod 15 is retracted. Thereby, the arm portion 6a
Is pushed back by the spring force, the gripper 6 is closed, and the shaft 2a of the welding torch 2 inserted through the opening 6c is gripped by the spring force. Thus, the sensor unit 3 is mounted on the shaft 2a of the welding torch 2 (step 102).

The controller 19 outputs the drive control signal S2 to move the welding torch 2 onto the work 20 as shown by the arrow B in FIG.
By moving the sensor unit 3 attached to the torch 2 along the welding line 21 (step 103). During this scanning, the detection signal S1 of the sensor 4 is sequentially input to the sensor controller 18 via the sensor amplifier 16 and the A / D converter 17 and stored (step 104). And the sensor controller 1
8 generates data indicating the shape and position of the welding line 21 based on the stored scanning data (step 105).

Next, the controller 19 outputs the drive control signal S2 to move the welding torch 2 onto the detachable base 5 again as shown by the arrow A in FIG. 1, and the sensor mounted on the shaft 2a of the welding torch 2 Position the unit 3 between the stoppers 12 and 13 on the removable base 5 (step 10).
6). When it is detected by the feedback signal S'2 that such positioning has been performed, the drive control signal S3 is output to drive the air cylinder 14, extend the rod 15, and open the gripper 6. As a result, the gripped state by the opening 6c of the shaft 2a of the torch 2 is released. Next, the drive control signal S2 is output, the welding torch 2 is moved upward, and the shaft 2a is removed from the opening 6c to a predetermined position. When the feedback signal S'2 detects that the welding torch 2 has been moved to such a predetermined position, the drive control signal S3 is output to the air cylinder 7 and the rod 15
Is degenerated. As a result, due to the spring force, the arm portion 6a
Is brought into contact with the stoppers 12 and 13, and the entire sensor unit 3 is locked again by the stoppers 12 and 13 (step 107).

Thereafter, the controller 19 proceeds to step 10
Based on the shape and position data of the welding line 21 generated in step 5, the teaching data of the welding line 21 is corrected and a new job for welding work is created, or a job already created is corrected ( In step 108), the welding work is performed by outputting the drive control signal S2 based on the created job (step 109).

As described above, according to this embodiment,
Since the sensor unit 3 itself does not have an actuator for changing the size of the opening 6c, there is an advantage that the sensor unit 3 can be designed compact and lightweight. Further, since the welding torch 2 is clamped by the spring force, the clamped state can be reliably maintained even when the robot 1 is stopped, such as during an emergency stop, and safety is improved. The effect is obtained.

The configuration for changing the size of the opening is not limited to the combination of the air cylinder 14 and the spring 10 as in the above-described embodiment, but a configuration utilizing a vacuum suction force, an electromagnetic force or the like. Can be adopted.

For example, FIG. 5 shows a configuration utilizing electromagnetic force.

As shown in FIG. 5A, the removable base 2
The stoppers 28 and 29 and the stopper 30 made of a magnetic material are arranged on the upper surface of the second unit 2, and the sensor unit 23 in which the gripper 24 and the welding line sensor 25 are integrated is regulated in the left and right directions by the stoppers 28 and 29. It is in a state. The sensor unit 23 includes a pair of electromagnetic solenoids 2 for changing the size of the opening 24a of the gripper 24.
6, 27 are provided so as to face each other.

Therefore, when the solenoids 26 and 27 are energized in a direction to repel each other, the gripper 24 is opened and the opening 24a is changed to the maximum size, as shown by the arrow in FIG. At this time, the solenoid 26 is attracted to the stopper 30, and the entire sensor unit 23 is positioned and fixed at that position.

In this state, the shaft 2a of the welding torch 2 is inserted through the opening 24a. When the welding torch 2 is inserted to a predetermined position, the solenoids 26 and 27 are energized in a direction to attract each other, and the sensor unit 23 is mounted on the shaft 2a of the welding torch 2 as shown in FIG. .

From the welding torch 2 to the sensor unit 2
In order to attach and detach 3, the same process may be performed in the order of FIGS. 5C, 5B, and 5A.

A nozzle is usually attached to the tip of the welding torch 2, but this nozzle needs to be detached when cleaning the nozzle. Therefore, an embodiment in which the working efficiency can be improved by performing the sensing by the welding line sensor when the nozzle is attached / detached will be described with reference to FIGS. 6 and 7.

FIG. 6A is a top view showing the structure of the sensor unit attaching / detaching device, and FIG. 6B is a side view thereof.

As shown in these figures, the attaching / detaching device is composed of two clampers 31, 32 arranged on the attaching / detaching base 31.

The clamper 31 is a clamper for the nozzle 33, and the hand 34 driven by the cylinder 35,
The nozzle 33 is sandwiched by 34. Meanwhile, clamper 3
A clamper 2 for the sensor unit 38 holds the sensor unit 38 by the hands 36, 36 driven by the cylinder 37.

The sensor unit 38 includes a welding line sensor 39.
And the gripper 40 are integrally formed units,
An opening 40a having the same diameter as the insertion hole 33a of the nozzle 33 is formed in the gripper 40. Therefore, the torch shaft 2a with the nozzle 33 not attached can be inserted into the opening 40a.

FIGS. 7A, 7B, 7C and 7D are as follows.
FIG. 7 is a diagram showing a procedure of processing for simultaneously mounting the sensor unit 38 and removing and mounting the nozzle 33.

First, the welding torch 2 having the nozzle 33 attached thereto is moved downward so as to be positioned between the hands 34 of the clamper 31, as shown by the arrow D in FIG. At this time, as shown by the arrow E, the space between the hands 34, 34 is opened so that the nozzle 33 is positioned between them.

Next, the hands 34, 34 are closed and the nozzle 33 is clamped, as shown by the arrow F in FIG. Then, the welding torch 2 is moved upward as shown by an arrow G, and the nozzle 33 is detached from the torch 2. Therefore, the nozzle 33 can be cleaned thereafter.

Next, the welding torch 2 is moved toward the clamper 32, and the opening 40 of the sensor unit 32 sandwiched by the clamper 32 is shown by the arrow in FIG.
It is moved downward so as to be inserted into a.

Thus, the shaft 2a of the torch 2 has the opening 40
When inserted into a, the hands 36, 36 of the clamper 32 are
Is opened, the sandwiched state of the sensor unit 38 is released, and the welding torch 2 to which the sensor unit 38 is attached is moved upward as shown by the arrow in FIG.
After that, the welding torch 2 with the sensor unit 38 attached
By moving the sensor along the welding line 21.
Sensing is executed.

After completion of sensing, (d) in FIG.
By performing the same processing in the order of (c), (b), and (a), the nozzle 33 can be attached and the sensor unit 38 can be attached and detached at the same time.

As described above, according to this embodiment, the attachment / detachment work can be efficiently performed in a short time by the simple operation of inserting and removing the tool into the opening provided in the detection device. Moreover, since the conventional robot does not require any modification, the cost is reduced.
Since the detection device is mounted on the tip of the tool, the detection range is wide and the tool does not interfere with other members during detection.

Next, an embodiment in which the measurement data of the welding line 21 is corrected based on the detection signal of the displacement sensor 4 will be described.

In this embodiment, as shown in FIG. 8, as the displacement sensor 4, the torch axis of the displacement sensor 4 is detected by one-dimensionally detecting the reflection position when the laser beam J is irradiated onto the work 20. Distance (displacement) between the mounting position (hereinafter referred to as "sensor position") R and the irradiation position PL with respect to 2a
It is assumed that the sensor detects. Then, in the sensor controller 18, the irradiation position of the laser beam in the robot coordinate system based on the robot tip position P (that is, the torch tip position 2a) based on the position of each axis of the robot 1 at the time of detecting the distance and the sensor position R. , That is, welding line 21
Position PM is detected.

However, as described above, the irradiation position P
M is accurately detected when the sensor unit 3 is mounted at a reference sensor position where the robot tip posture axis G, which is the torch axis center, and the projection laser optical axis (reference axis) H are parallel to each other. However, when the sensor unit 3 is attached with a deviation from the reference sensor position, the optical axis deviation α
Occurs, and a detection error ε occurs between the actual irradiation position PL and the calculated irradiation position PM.

Therefore, in this embodiment, the above detection error is corrected by the processing procedure as shown in FIG. The processing contents of FIG. 10 will be described below with reference to FIG.

That is, first, prior to the correction process, as shown in FIG. 9, a reference edge on which the coordinate position PE in the robot coordinate system XZ is measured in advance is set on the work 20.

Then, each axis of the robot 1 is driven, and the height Z of the sensor unit 3 is sequentially changed to different heights (level i = 0,
1, 2 ... N), and each axis of the robot 1 is driven and controlled so that the laser beam emitted from the displacement sensor 4 scans the reference edge in the X direction for each height.

As a result, the scanning data Di indicating the correspondence between the robot tip position P based on each robot axis position and the output (sensor height) Z of the displacement sensor 4 for each height i.
(I = 0, 1, 2, ... N) is acquired. Note that each height i
It is assumed that the scanning conditions for each are taught in advance (steps 201, 202, 203).

Next, analysis processing is performed on the scan data Di, and characteristic data when the sensor height detection signal Z changes greatly is taken as the sensor height Zi at the time of detecting the reference edge. Then, the robot tip position Pi is associated with the sensor height Zi (step 204).

When the above processing is completed for all heights (NO at step 205), the optical axis position parameters ΔSR, ΔSz, α for correction are as follows based on the already detected data Pi, Zi. Is calculated.

That is, the distance between the robot tip position P and the sensor position R in the X direction is defined as ΔSR, and the distance between the robot tip position P and the sensor position R in the Z direction is defined as ΔSz.

Then, the deviation Xi in the X direction between the robot tip position Pi and the reference edge position PE at the time of detecting the above-mentioned reference edge.
Is obtained by the following formula: Xi = | Pi (x) -PE (x) | (1) (where the subscript (x) in the above formula represents the X coordinate component). Further, from the geometrical relationship, the relationship Xi = tan α · Zi + ΔSR (2) holds.

Therefore, regarding the above equation (2), Xi, Zi
Is used as a parameter to perform linear approximation using the method of least squares, and tan α and ΔSR are obtained as in the following equations (3) and (4).

[0078] Further, ΔSz is obtained by the following equation (5) using one level of data.

ΔSz = Zi− | Pi (z) −PE (z) | (5) (In the above formula, the subscript (z) represents the Z coordinate component.) Thus, the optical axis position correction parameters ΔSR, ΔSz, ta
When nα is calculated, these correction parameters, Z which is the detection value of the displacement sensor 4, and the robot tip position P = [P (x), P (y), P (z)] at the time of the detection are calculated. , Laser light irradiation position PL = [P (x), P (y), P (z)] is calculated as follows.

PL (x) = P (x) + ΔSR + Ztanα PL (y) = P (y) PL (z) = P (z) -ΔSz-Z (6) In this way, the optical axis deviation is corrected and accurate. It is possible to detect the proper laser light irradiation position, that is, the position of the welding line (step 206).

In this embodiment, a laser displacement sensor is assumed as the welding line sensor, but it can be applied to any sensor such as an image sensor.

[0082]

As described above, according to the present invention,
Since only the detection device is configured to be detachable from the tool without requiring any change on the tool side, the work efficiency can be improved and the cost can be reduced. Further, the detection range of the detection device is expanded, and the tool does not interfere with other members during detection.

Further, according to the present invention, the machining work line detected by the detection device is corrected based on the detection signal when the detection device is attached to the tool and the reference machining work line is detected by the detection device. As a result, the work efficiency is improved, the work is performed safely, the cost is reduced, and the correction accuracy is dramatically improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a robot system applied to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of an attaching / detaching device according to an embodiment, and is a diagram of an attaching / detaching base fixed to a predetermined position of the robot shown in FIG.

FIG. 3 is a cross-sectional view taken along line CC of the sensor unit locked on the removable base of FIG.

FIG. 4 is a flowchart showing a procedure of processing executed by the robot controller and the sensor controller shown in FIG.

5 (a), (b), and (c) are diagrams showing a state of mounting performed by an attaching / detaching device having a configuration different from that of the attaching / detaching device shown in FIG.

6 (a) and 6 (b) are a top view and a side view showing a configuration of an attachment / detachment device that simultaneously performs cleaning of a nozzle and attachment / detachment of a sensor unit.

7 (a), (b), (c), and (d) of FIG.
It is a figure which shows the mode of attachment which can be attached to the attachment / detachment device shown in FIG.

FIG. 8 is a diagram for explaining how the optical axis of the laser beam emitted from the displacement sensor when the displacement sensor of the embodiment is attached to the welding torch is misaligned.

FIG. 9 is a diagram for explaining how a reference edge is provided on the laser light irradiation surface to correct the optical axis deviation.

FIG. 10 is a flowchart showing a processing procedure for correcting the position of a welding line.

[Explanation of symbols]

 1 Robot 2 Welding torch 2a Axis 3 Sensor unit 6c Opening

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B23K 9/127 509 B 8315-4E B23Q 35/04 B 35/128 A G05B 19/42

Claims (5)

[Claims] 1. A robot that is applied to a robot that performs a predetermined machining operation by moving a tip of a tool attached to an arm tip along a machining operation line, and detects the machining operation line before the machining operation. A processing work line detection device, wherein the detection device is configured to be detachable from the tool. 2. The processing line detecting device for a robot according to claim 1, wherein the detecting device is provided with an opening into which the tool is inserted. 3. The detecting device is further provided with changing means for changing the size of the opening, and the changing means enlarges the opening to allow the tool to be inserted into the opening. 3. A processing line detecting device for a robot according to claim 2, wherein the changing means reduces the size of the opening to hold the inserted tool. 4. The processing device is attached to the tool, and the processing work line detected by the detection device is corrected based on a detection signal when the reference processing work line is detected by the detection device. The processing device for detecting the working line of the robot according to claim 1. 5. The detection device detects a distance between the detection device and a machining work line, and also robot posture data indicating a posture of the robot at the time of detection and a mounting position indicating a mounting position of the detection device on a tool. A detection device for detecting the position of the machining work line based on position data, wherein the detection device is attached to the tool, and the height of the detection device is changed to a reference machining work line by the detection device. Is detected, based on the detected distance data for each height of the detection device, the robot posture data for each height of the detection device, and the data indicating the position of the reference machining work line, the detection The robot processing line detection device according to claim 4, wherein the position of the processing line detected by the device is corrected.