KR20150025553A - Calibration Method for Welding Torch Deformation of Welding Robot and Welding Robot System - Google Patents

Abstract

The present invention relates to a method of compensating deformation in a welding torch of a welding robot which includes steps of: inserting a welding nozzle of a welding torch into a sensing hole formed on a sensor; moving a welding robot to compensate tilting of the welding nozzle in order to enable the welding nozzle to be stood in a vertical direction using a nozzle contact signal generated as the welding nozzle comes in contact with the sensor; inserting a welding wire mounted on the welding nozzle into the sensing hole; moving the welding robot to obtain wire deformation information regarding the vertically-stood welding nozzle using a wire contact signal generated as the welding wire comes in contact with the sensor; and compensating deformation of the welding torch in accordance with the wire deformation information, and a welding robot system. According to the present invention, when a welding torch is deformed, a welding process using a welding robot is prevented from being performed like when the welding torch is not deformed. Therefore, the quality of a welded matter is prevented from being degraded.

Description

Technical Field [0001] The present invention relates to a welding torch,

The present invention relates to a welding torch deformation correcting method and a welding robot system for a welding robot performing a welding process.

Such as ships, cranes, etc., are manufactured through various processes such as a welding process, a processing process, and the like. For example, a large-sized ship is dried by a welding process in which a plurality of kinds of plate materials, pipes, and other workpieces are welded in accordance with a purpose of use, a use position, and the like. A welding robot is used to perform the welding process on these workpieces.

1 is a schematic perspective view showing a welding torch of a general welding robot.

Referring to Fig. 1, the welding robot performs a welding process on the workpiece. The welding robot includes a welding torch 10 for supplying wires and gas and generating an arc toward the base material. The welding torch 10 includes a torch body 11 through which wires and gas pass, a welding nozzle 12 mounted on the torch body 11, a welding nozzle 12 And a welding wire 13 supplied through the center of the welding wire 13. The welding robot further includes a robot arm (14) on which the welding torch (10) is mounted. The welding robot can move the welding torch 10 by moving the robot arm 14. Accordingly, the welding robot performs a welding process on the workpiece to be welded.

Here, the welding robot is deformed in the welding torch 10 due to various factors such as the collision of the welding torch 10 with the surrounding equipment in the process of moving the robot arm 14. When the welding robot continues to perform the welding process in a state where deformation has occurred in the welding torch 10 or the like, the welding proceeds at a position deviating from the previously recorded welding working position. Therefore, There is a problem of deteriorating quality.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide a welding torch deformation correcting method and a welding robot system for a welding robot capable of preventing degradation in quality of a workpiece as deformation occurs in the welding torch .

In order to solve the above-described problems, the present invention can include the following configuration.

A welding torch deformation correction method of a welding robot according to the present invention includes the steps of: inserting a welding nozzle of a welding torch into a detection hole formed in a sensing mechanism; Moving the welding robot to correct the tilting of the welding nozzle so that the welding nozzle is vertically erected using a nozzle contact signal generated as the welding nozzle contacts the sensing mechanism; Inserting a welding wire mounted on the welding nozzle into the sensing hole; Moving the welding robot to obtain wire deformation information on the welding wire deformed by the welding wire with respect to the vertically oriented welding nozzle using a wire contact signal generated as the welding wire contacts the sensing mechanism; And correcting the deformation of the welding torch according to the wire deformation information.

In the welding torch deformation correcting method of the welding robot according to the present invention, the step of correcting the deformation of the welding torch may comprise: if the deformation of the welding torch is less than a preset reference range, And correcting the deformation of the welding torch.

In the welding torch deformation correcting method of the welding robot according to the present invention, the step of inserting the welding nozzle into the detection hole may include: lowering the welding nozzle by a predetermined distance; Moving the welding nozzle in a first direction when the welding nozzle is lowered by a predetermined distance; Moving the welding nozzle in a second direction perpendicular to the first direction after raising the welding nozzle by a predetermined distance if the nozzle contact signal and the wire contact signal are not received; And moving the welding nozzle in the first direction until the nozzle contact signal or the wire contact signal is received, And then performing the step of moving in the second direction repeatedly.

In the welding torch deformation correction method of the welding robot according to the present invention, the step of correcting the tilting of the welding nozzle may include moving the welding robot so that a first portion of the welding nozzle inserted into the sensing hole contacts the sensing mechanism Using the first nozzle contact signal to generate first nozzle coordinate information, the first nozzle coordinate information being spaced apart from the central coordinate of the sensing hole; Moving the welding robot so that the welding nozzle is lowered when the first nozzle coordinate information is obtained, thereby inserting a second portion of the welding nozzle spaced apart from the first portion into the sensing hole; And a second nozzle contact signal generated as the second portion inserted into the detection hole is brought into contact with the sensing mechanism by moving the welding robot so that the second portion is spaced apart from the center coordinates of the sensing hole, Obtaining coordinate information; And deriving tilting information in which the welding nozzle is tilted with respect to the vertical direction from the first nozzle coordinate information and the second nozzle coordinate information and moving the welding robot according to the derived tilting information, In the vertical direction.

In the welding torch deformation correction method of the welding robot according to the present invention, the step of correcting the tilting of the welding nozzle may be performed by moving the welding robot so that the welding nozzle inserted into the sensing hole Acquiring nozzle coordinate information of the welding nozzle spaced apart from the central coordinate of the sensing hole using a nozzle contact signal; Positioning the welding nozzle on the upper side of the sensing mechanism by moving the welding robot according to the central coordinate and the nozzle coordinate information and positioning the welding wire on the upper side of the sensing hole; And moving the welding robot so that the welding nozzle is lowered to derive height information of the welding nozzle using a nozzle contact signal generated as the welding nozzle contacts the sensing mechanism. The step of correcting the deformation of the welding torch may include correcting the reference coordinates set before obtaining the nozzle coordinate information to the reference coordinates obtained according to the nozzle coordinate information and the height information.

In the welding torch deformation correction method of the welding robot according to the present invention, the step of correcting the tilting of the welding nozzle may be performed by moving the welding robot so that the welding nozzle inserted into the sensing hole And using the nozzle contact signal to obtain nozzle coordinate information that is spaced from the center coordinate of the sensing hole by the welding nozzle. Wherein the step of acquiring the wire deformation information further comprises the step of moving the welding robot so that the welding wire is moved to the center coordinate of the sensing ball by using a wire contact signal generated as the welding wire inserted into the sensing ball contacts the sensing mechanism Obtaining wire coordinate information from the nozzle coordinate information and the wire coordinate information, and obtaining the wire deformation information from the nozzle coordinate information and the wire coordinate information.

A welding robot system according to the present invention includes a welding robot for performing a welding process, the welding robot including a welding torch and a robot arm for moving the welding torch; A detection mechanism having a detection hole for inserting at least one of a welding nozzle and a welding wire of the welding torch; A first signal generator connected to the welding nozzle and generating a nozzle contact signal when the welding nozzle contacts the sensing mechanism; A second signal generator connected to the welding wire and generating a wire contact signal when the welding wire contacts the sensing mechanism; And a control unit for correcting the tilting of the welding nozzle from the nozzle contact signal and the wire contact signal and controlling the welding robot to correct deformation of the welding torch in accordance with the deformed wire deformation information .

In the welding robot system according to the present invention, when the wire deformation information is less than a preset reference range, the controller acquires reference coordinates for the welding nozzle set up in the vertical direction to correct deformation of the welding torch.

According to the present invention, the following effects can be obtained.

The present invention prevents the welding process from being performed using the welding robot in the same manner as before the welding torch is deformed in the state where the welding torch is deformed so that the quality of the to-be- .

The present invention can be implemented so as to automatically correct tool data for a welding torch when a deformation occurs in the welding torch, thereby improving the accuracy of the welding process.

1 is a schematic perspective view showing a welding torch of a general welding robot;
2 is a schematic block diagram of a welding robotic system according to the present invention
3 is a schematic flowchart of a welding torch deformation correcting method of a welding robot according to the present invention
4 is a schematic flowchart of a process for inserting a welding nozzle according to the present invention into a detection hole and a process for correcting the tilting of the welding nozzle
FIG. 5 is a schematic plan view for explaining a process of inserting a welding nozzle into a detection hole by a welding robot system according to the present invention
6 to 8 are schematic views for explaining the process of correcting the tilting of the welding nozzle by the welding robot system according to the invention
9 is a side sectional view for explaining the process of deriving the height information of the welding nozzle by the welding robot system according to the present invention
10 is a schematic flowchart of a welding torch deformation correcting method of a welding robot according to another modified embodiment of the present invention
11 is a schematic plan view for explaining the process of obtaining the wire deformation information by the welding robot system according to the present invention

It should be noted that, in the specification of the present invention, the same reference numerals as in the drawings denote the same elements, but they are numbered as much as possible even if they are shown in different drawings.

Meanwhile, the meaning of the terms described in the present specification should be understood as follows.

The word " first, "" second," and the like, used to distinguish one element from another, are to be understood to include plural representations unless the context clearly dictates otherwise. The scope of the right should not be limited by these terms.

It should be understood that the terms "comprises" or "having" does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

It should be understood that the term "at least one" includes all possible combinations from one or more related items. For example, the meaning of "at least one of the first item, the second item and the third item" means not only the first item, the second item or the third item, but also the second item and the second item among the first item, Means any combination of items that can be presented from more than one.

Hereinafter, preferred embodiments of the welding robot system according to the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 2, the welding robot system 100 according to the present invention is for performing a welding process on a workpiece using a welding robot 1 in the process of manufacturing a ship, a crane, or the like. The welding robot 1 includes a robot arm 1a for moving to perform a welding process, and a welding torch 2 mounted on the robot arm 1a. The welding torch 2 includes a torch body 21 mounted on the robot arm 1a, a welding nozzle 22 mounted on the torch body 21, and a welding wire 23. The welding wire 23 may be supplied so as to protrude outside the welding nozzle 22 through the center of the welding nozzle 22 while being insulated from the welding nozzle 22. [ The welding robot 1 moves the robot arm 1a along a welding line, thereby moving the welding torch 2 to perform a welding process on the workpiece.

The welding torch 2 is deformed due to various factors such as a collision of the welding torch 2 with a surrounding tool or the like in the process of moving the robot arm 1 a by the welding robot 1 Lt; / RTI > For example, various deformations may occur in the welding torch 22 due to tilting of the welding nozzle 22 or bending of the welding wire 23.

The welding robot system 100 according to the present invention includes a sensing mechanism 3 for determining whether or not a deformation has occurred in the welding torch 2, a first signal generator 4 connected to the welding nozzle 22, A second signal generating unit 5 connected to the welding wire 23, and a control unit 6 for controlling the welding robot 1. [

The sensing mechanism (3) includes a sensing hole (31) for insertion of at least one of the welding nozzle (22) and the welding wire (23). The first signal generator 4 generates a nozzle contact signal when the welding nozzle 22 contacts the sensing mechanism 3. The second signal generator 5 generates a wire contact signal when the welding wire 23 contacts the sensing mechanism 3. The control unit 6 corrects the tilting and positional change of the welding nozzle 22 using the nozzle contact signal and the wire contact signal so that the welding wire 23 can obtain the deformed wire deformation information have.

For example, when the wire deformation information is within a predetermined range, the control unit 6 controls the reference coordinates, which are set before the deformation occurs in the welding torch 2, It is possible to automatically correct the reference coordinates obtained by reflecting the inclination and the positional change. Accordingly, the control unit 6 can automatically correct the tool data for the welding torch 2. The welding robot system 100 according to the present invention can control the welding robot 1 so that the welding torch 2 performs the welding process on the workpiece based on the corrected tool data.

Accordingly, in the welding robot system 100 according to the present invention, in a state in which the welding torch 2 is deformed, the welding robot 2, based on the tool data stored before the welding torch 2 is deformed, It is possible to prevent the occurrence of welding defects in the workpiece having been completed by performing the welding at a position deviating from the previously recorded welding work position. Thus, the welding robot system 100 according to the present invention can improve the accuracy of the welding process by automatically correcting the tool data for the welding torch 2 when a deformation occurs in the welding torch 2. Therefore, the welding robot system 100 according to the present invention can prevent the quality of the workpiece from being lowered even if the welding torch 2 is deformed.

Hereinafter, the welding robot 1, the welding torch 2, the sensing mechanism 3, the first signal generator 4, the second signal generator 5, and the controller 6 Will be described in detail with reference to the accompanying drawings.

Referring to Fig. 2, the welding robot 1 performs a welding process on a workpiece to be welded. The welding robot (1) includes a robot arm (1a) on which the welding torch (2) is mounted. The welding robot 1 can move the welding torch 2 by moving the robot arm 1a to perform a welding process on the workpiece.

The robot arm 1a is operated by a driving unit (not shown). As the robot arm 1a is operated by the driving unit, the welding torch 2 can perform a welding process on the workpiece. The robot arm 1a is moved to move in at least one of a horizontal direction and a vertical direction so that the welding torch 2 can be moved in at least one of the horizontal direction and the vertical direction. The robot arm 1a may include a plurality of joints rotating about different axes. The driving unit may be a cylinder type using a hydraulic cylinder or a pneumatic cylinder, a ball screw type using a motor and a ball screw, a gear type using a motor, a rack gear and a pinion gear, A belt system using a pulley and a belt, a servomotor using a coil and a permanent magnet, or the like, to operate the robot arm 1a.

Referring to Fig. 2, the welding torch 2 is mounted on the robot arm 1a. The welding torch 2 can perform the welding process on the workpiece while moving as the robot arm 1a moves. The welding torch 2 may include the torch body 21, the welding nozzle 22, and the welding wire 23.

The torch body 21 is mounted on the robot arm 1a so as to be positioned between the robot arm 1a and the welding nozzle 22. [ The torch body 21 and the welding nozzle 22 pass the welding wire 24 and the gas supplied to perform the welding process on the workpiece. When the welding robot 1 is an arc welding robot, the torch body 21 may generate an arc flame. The torch body 21 may be formed as a rod bent at a predetermined angle at a predetermined position as a whole, but may be formed in various other shapes.

The welding nozzle 22 is mounted on the torch body 21 so as to be positioned between the torch body 21 and the welding wire 23. The welding nozzle 22 is connected to the first signal generator 4. [ The welding nozzle 22 may be connected to the first signal generating unit 4 through an electric wire or the like. The welding nozzle 22 may be formed in a cylindrical shape as a whole, but it is not limited thereto and may be formed in various other forms.

The welding wire 23 is positioned on the opposite side of the torch body 21 with respect to the welding nozzle 22. The welding wire 23 may be supplied so as to protrude outside the welding nozzle 22 through the center of the welding nozzle 22 while being insulated from the welding nozzle 22. [ Although not shown, the welding robot 1 is provided with a wire feeder 23 for feeding the welding wire 23 so that the welding wire 23 passes through the welding nozzle 23 while being insulated with respect to the welding nozzle 23 Means. The welding wire (23) is connected to the second signal generator (5). The welding wire 23 may be electrically connected to the second signal generator 5 through a welding power supply line or the like. The welding wire 23 may be formed as a rod as a whole, but it is not limited thereto and may be formed in various other forms.

Referring to FIG. 2, the sensing mechanism 3 is installed so as to be spaced apart from the welding robot 1. The sensing mechanism 3 may be coupled to a pedestal (not shown) that supports the workpiece during the welding process. The sensing hole 3 is formed in the sensing mechanism 3. The sensing mechanism 3 may be formed of a conductive material through which electricity can flow.

The sensing hole (31) is formed through the sensing mechanism (3). The sensing hole 31 may be formed to have a size such that the welding nozzle 22 inserted therein can move within a predetermined range. The sensing hole 31 may be formed to have a size such that the inserted welding wire 23 can move within a predetermined range. The sensing hole 31 may be formed in a disc shape having a predetermined diameter.

Referring to FIG. 2, the first signal generator 4 is connected to the welding nozzle 22. The first signal generator 4 may be connected to the welding nozzle 22 through an electric wire or the like. The first signal generating unit 4 generates a current change or a voltage change caused by the contact of the welding nozzle 22 with the sensing mechanism 3 in a state where power is supplied to the welding nozzle 22 By sensing, the nozzle contact signal can be generated. The first signal generator 4 may provide the nozzle contact signal to the controller 6. The controller 6 may receive the nozzle contact signal from the first signal generator 4 using at least one of wire communication and wireless communication. The first signal generator 4 may be connected to the welding nozzle 22 and the sensing member 3, respectively.

Referring to FIG. 2, the second signal generator 5 is connected to the welding wire 23. The second signal generator 5 may be connected to the welding wire 23 via a welding power supply line or the like. The second signal generating unit 5 generates a current change or a voltage change caused by the contact of the welding wire 23 with the sensing mechanism 3 in a state where power is supplied to the welding wire 23 Thereby generating the wire contact signal. And the second signal generator 5 may provide the wire contact signal to the controller 6. [ The controller 6 may receive the wire contact signal from the second signal generator 5 using at least one of wire communication and wireless communication. The second signal generator 5 may be electrically connected to the welding wire 23 and the sensing member 3, respectively. The second signal generator 5 may be a welding machine connected to the welding robot 1.

The second signal generating unit 5 and the first signal generating unit 4 are connected to the welding nozzle 22 and the welding wire 23 by using separate wires and welding power lines. Accordingly, the controller 6 can control the welding robot 1 by clearly dividing the nozzle contact signal and the wire contact signal. Therefore, the welding robot system 1 according to the present invention can improve the accuracy of the work for correcting deformation occurring in the welding torch 2.

Referring to FIG. 2, the controller 6 controls the welding robot 1 according to the nozzle contact signal and the wire contact signal.

The controller 6 may control the nozzle contact provided from the first signal generator 4 when the welding nozzle 22 contacts the sensing mechanism 3 while being inserted into the sensing hole 31 and moving, The tilting information for the welding nozzle 22 can be obtained using a signal. The control unit 6 can control the welding robot 1 so that the welding nozzle 22 is vertically erected using the inclination information. The vertical direction means a direction in which the welding nozzle 22 faces when the welding torch 2 is not deformed. Accordingly, the control unit 6 can correct the tilting of the welding nozzle 22. Therefore, the welding robot system 100 according to the present invention can prevent the welding process from being performed in a state where the welding nozzle 22 is tilted, thereby preventing welding defect from occurring in the welding process completed welding process . The tilting information is obtained by moving the welding nozzle 22 so that two or more different portions of the welding nozzle 22 are sequentially brought into contact with the sensing mechanism 3, Or more of each of the plurality of portions is contacted with the sensing mechanism 3. [

The control unit 6 uses the inclination information to erect the welding nozzle 22 in the vertical direction to correct the tilting of the welding nozzle 22, The welding nozzle 22 can be moved so as to be brought into contact with the work 3. Accordingly, the control unit 6 determines whether or not the tilting correction for the welding nozzle 22 has been performed correctly, thereby reducing an error in correcting the tilting correction for the welding nozzle 22 . In this process, the controller 6 may obtain the center coordinates of the sensing hole 31 in a state where the inclination of the welding nozzle 22 is corrected.

The control unit 6 can derive the height information of the welding nozzle 22 after correcting the tilting of the welding nozzle 22. [ Specifically, it is as follows.

The control unit 6 controls the welding robot 22 so that the welding nozzle 22 is positioned on the upper side of the sensing mechanism 3 and the welding wire 23 is positioned on the upper side of the sensing hole 31 ).

Next, when the welding nozzle 22 is positioned on the upper side of the sensing mechanism 3 and the welding wire 23 is positioned on the upper side of the sensing hole 31, the control unit 6 controls the welding nozzle 22) is lowered until the welding nozzle (22) is brought into contact with the sensing mechanism (3).

Next, the controller 6 can derive the height information of the welding nozzle 22 using the nozzle contact signal generated as the welding nozzle 22 is lowered and contacts the sensing mechanism 3 .

When the height information of the welding nozzle 22 is obtained after the tilting of the welding nozzle 22 is corrected through the above-described process, the controller 6 controls the welding nozzle 22 to detect the height And controls the welding robot 1 to be positioned at a height spaced upward from the center coordinate of the ball 31 by a predetermined distance. Accordingly, the controller 6 can acquire a new reference coordinate for the welding nozzle 22. In this case, in the process of setting the reference coordinates before acquiring the inclination information, the controller 6 controls the welding nozzle 22 so that the distance from the center of the sensing hole 31 to the upper side The welding nozzle 22 can be moved to the position shown in Fig.

Accordingly, the control unit 6 compares the reference coordinates set before obtaining the inclination information and the reference coordinates newly obtained after obtaining the inclination information, so that the welding nozzle 22 is deformed Or not. When the welding nozzle 22 is deformed, the control unit 6 stores newly obtained reference coordinates.

The control unit 6 controls the wire contact provided from the second signal generating unit 5 when the welding wire 23 contacts the sensing mechanism 3 while being inserted into the sensing hole 31 and moving, The welding wire 23 can obtain deformed wire strain information by using a signal. The wire deformation information refers to a direction in which deformation has occurred in the welding wire 23 and a direction in which deformation has occurred based on the welding nozzle 22 set up in the vertical direction.

When the wire deformation information is acquired, the controller 6 determines whether the wire deformation information is within a predetermined range. The predetermined range for the wire deformation information can be preset by the user. The control unit 6 may determine whether the wire deformation information is within a preset range based on the center coordinates of the sensing hole 31 obtained after the welding nozzle 22 is set in the vertical direction.

If the wire deformation information is less than a predetermined range, the control unit 6 corrects the reference coordinates set before the welding torch 2 is deformed to the tilting and position of the welding nozzle 22, It is possible to correct the deformation with respect to the welding torch 2 by automatically correcting it to one reference coordinate. Therefore, the welding robot system 100 according to the present invention can prevent welding defect from occurring in the workpieces to be welded. Further, the welding robot system 100 according to the present invention can control the welding robot 1 so that the welding torch 2 performs the welding process on the workpiece based on the corrected tool data. Therefore, the welding robot system 100 according to the present invention not only improves the operation rate of the welding robot 1 but also improves the productivity of the workpieces to which the welding process is completed.

If the wire deformation information is in a predetermined range or more, the controller 6 can stop the welding robot 1 and output a warning sound or warning message. Therefore, the welding robot system 100 according to the present invention can prevent welding defects from occurring in the workpieces that have been subjected to the welding process, and it is possible to promptly perform follow-up measures such as repairing the welding robots 1 . ≪ / RTI >

Hereinafter, preferred embodiments of a welding torch deformation correcting method of a welding robot according to the present invention will be described in detail with reference to the accompanying drawings.

2 and 3, a method for correcting a welding torch deformation of a welding robot according to the present invention can be performed using the welding robot system 100 described above. The welding torch deformation correcting method of the welding robot according to the present invention may include the following configuration.

First, the welding nozzle 22 is inserted into the sensing hole 31 (S100). This step S100 may be performed by controlling the welding robot 1 such that the control unit 6 inserts the welding nozzle 22 into the sensing hole 31. [

Next, the tilting of the welding nozzle 22 is corrected (S200). This process (S200) may be performed by controlling the welding robot (1) so that the control unit (6) moves the welding nozzle (22) in a state of being inserted into the detection hole (31). When the first signal generator 4 generates the nozzle contact signal as the welding nozzle 22 contacts the sensing mechanism 3 while the welding nozzle 22 is inserted into the sensing hole 31 and moves, (6) obtains inclination information for the welding nozzle (22) by using a nozzle contact signal provided from the first signal generating unit (4) and outputs the inclination information to the welding nozzle (22) The welding robot 1 can be controlled.

 Therefore, the welding torch deformation correction method of the welding robot according to the present invention prevents the welding process from being performed in the state where the welding nozzle 22 is tilted, thereby causing a welding defect in the welding target . Accordingly, the welding torch deformation correction method of the welding robot according to the present invention can prevent degradation of the quality of the to-be-welded work that has been completed even if deformation occurs in the welding torch 2. The inclination information may be obtained by moving two or more different parts of the welding nozzle 22 so as to be in contact with the sensing mechanism 3 sequentially so that each of two or more different parts of the welding nozzle 22 Can be obtained using the distance difference that travels until it comes into contact with the mechanism (3).

The step of correcting the tilting of the welding nozzle 22 is a step of setting the welding nozzle 22 in the vertical direction to correct the tilting of the welding nozzle 22, The welding nozzle 22 may be moved so as to contact the detection mechanism 3 again. Accordingly, the welding torch deformation correcting method of the welding robot according to the present invention can correct the inclination correction for the welding nozzle 22 by checking whether or not the skew correction for the welding nozzle 22 has been performed correctly So that the occurrence of errors can be reduced. In addition, the welding torch deformation correction method of the welding robot according to the present invention can confirm whether the position of the welding nozzle 22 is changed before, after, left, or right.

The step of correcting the tilting of the welding nozzle 22 may be performed after deriving the height information of the welding nozzle 22 in a state in which the tilting of the welding nozzle 22 is corrected, 22 can be located at a height spaced upward from the center coordinate of the sensing hole 31 by a predetermined distance, thereby obtaining a new reference coordinate for the welding nozzle 22. [

Accordingly, the method for correcting welding torch deformation of the welding robot according to the present invention is a method for correcting the welding torch deformation of the welding robot by comparing the reference coordinates set before obtaining the inclination information and the reference coordinates newly set after acquiring the inclination information, 22 can be confirmed whether or not deformation has occurred. When the welding nozzle 22 is deformed, the control unit 6 automatically corrects the reference coordinates set before acquiring the inclination information to the newly set reference coordinates after acquiring the inclination information, The deformation of the torch 2 can be automatically corrected.

Next, the welding wire 23 is inserted into the sensing hole 31 (S300). This step S300 may be performed by controlling the welding robot 1 such that the control unit 6 inserts the welding wire 23 into the sensing hole 31. [

Next, the wire deformation information is obtained (S400). This step S400 may be performed by controlling the welding robot 1 such that the control unit 6 moves the welding wire 23 in a state where the welding wire 23 is inserted into the sensing hole 31. [ When the second signal generator 5 generates the wire contact signal as the welding wire 23 contacts the sensing mechanism 3 while the welding wire 23 is inserted into the sensing hole 31 and moves, (6) can obtain the wire strain information of the welding wire (23) deformed with respect to the vertically oriented welding nozzle (22) by using the wire contact signal provided from the second signal generator have. Therefore, the welding torch deformation correcting method of the welding robot according to the present invention prevents the welding process from being performed in the state where the welding wire 23 is deformed, thereby preventing the welding defect from occurring in the welding target can do. Accordingly, the welding torch deformation correction method of the welding robot according to the present invention can prevent degradation of the quality of the workpiece after the welding process is completed.

2, 4 and 5, the step S100 of inserting the welding nozzle 22 into the sensing hole 31 may include the following configuration.

First, the welding nozzle 22 is lowered (S110). This process (S100) may be performed by controlling the welding robot (1) so that the control section (6) descends the welding nozzle (22) by a predetermined distance. The predetermined distance may be preset by the user to a distance at which the welding wire 23 can be inserted into the sensing hole 31. The predetermined distance may be a distance at which the welding nozzle 22 can be inserted into the sensing hole 31.

Next, the welding nozzle 22 is moved to the first direction (arrow A direction, shown in Fig. 5) (S120). In this step S120, when the welding nozzle 22 is lowered by a predetermined distance, the control unit 6 controls the welding robot 22 so that the welding nozzle 22 moves in the first direction (arrow A direction) ). ≪ / RTI > The first direction A may be a direction parallel to the direction of the sensing mechanism 3 and parallel to the bottom of the workplace where the sensing mechanism 3 is installed.

Next, it is determined whether the nozzle contact signal or the wire contact signal is received (S130). If the nozzle contact signal and the wire contact signal are not received, the welding nozzle 22 is moved in the second direction 5) (S140).

(S130) of determining whether the nozzle contact signal or the wire contact signal is received is determined based on whether the controller 6 receives the nozzle contact signal or the wire contact signal from the first signal generator 4 and the second signal generator 5 By checking whether a contact signal or the wire contact signal is received.

(S140) of moving the welding nozzle 22 in the second direction (the direction of the arrow B) is performed after the welding nozzle 22 is raised by the predetermined distance in the second direction B direction of the welding robot 1). The second direction (arrow B direction) may be a direction perpendicular to the first direction (arrow A direction) and parallel to the bottom of the workplace where the sensing mechanism 3 is installed.

The step S100 of inserting the welding nozzle 22 into the detection hole 31 is a step of descending the welding nozzle 22 by a predetermined distance until the nozzle contact signal or the wire contact signal is received A step S120 of moving the welding nozzle 22 in the first direction A direction and a step S130 of determining whether the nozzle contact signal or the wire contact signal is received, (Step S 140) of moving the welding nozzle 22 in the second direction (the arrow B direction) after raising the welding nozzle 22 by a predetermined distance.

This repeated execution process is repeated until the control section 6 receives the nozzle contact signal or the wire contact signal from the first signal generating section 4 or the second signal generating section 5, (22) is lowered by a predetermined distance and is moved in the first direction (A arrow direction), and it is determined whether the nozzle contact signal or the wire contact signal is received, and the welding nozzle (22) And then moving the welding robot 1 in the second direction (arrow B direction) after being raised.

For example, as the welding nozzle 22 is lowered (S100), the lowered welding nozzle 22 is positioned at a first point S1 (shown in FIG. 5) which is outside the sensing hole 31 The welding nozzle 22 and the welding wire 23 are brought into contact with the sensing mechanism 3 even if the step of moving the welding nozzle 22 in the first direction Can not be. In this case, the welding torch deformation correction method of the welding robot according to the present invention determines that the welding nozzle 22 is positioned outside the sensing hole 31 (S130) (Step S 140) in the second direction (the arrow B direction).

For example, when the welding nozzle 22 is lowered (S100), the lowered welding nozzle 22 is positioned at the second point S2 (shown in FIG. 5) inside the sensing hole 31 The welding nozzle 22 or the welding wire 23 is moved to the detection mechanism 3 in the first direction A in the first direction . In this case, the welding torch deformation correction method of the welding robot according to the present invention can complete the process of inserting the welding nozzle 22 into the detection hole 31.

The step S100 of inserting the welding nozzle 22 into the detection hole 31 may be performed when the nozzle contact signal and the wire contact signal are not received even after the repetition of the predetermined number of times Well, you can print error messages and so on.

2, 4 and 6 to 8, a step S200 of correcting the tilting of the welding nozzle 22 is performed by moving the welding robot 1 so as to move the welding robot 22 inserted in the detection hole 31 The welding nozzle 22 is moved from the center coordinate (OP, shown in FIG. 6) of the sensing hole 3 by using the nozzle contact signal generated as the welding nozzle 22 contacts the sensing mechanism 3 And acquiring the spaced nozzle coordinate information. Specifically, it is as follows.

First, the first portion 221 of the welding nozzle 22 (shown in FIG. 7) is inserted into the sensing hole 31 (S210). This step S210 may be performed by controlling the welding robot 1 such that the control part 6 inserts the first part 221 of the welding nozzle 22 into the sensing hole 31. [ The step of inserting the first portion 221 of the welding nozzle 22 into the sensing hole 31 includes the step of inserting the welding nozzle 22 into the sensing hole 31 And lowering the welding nozzle 22 by a predetermined reference height after completion. The reference height may be preset by the user.

Next, the first nozzle coordinate information is obtained (S220). This step S220 is a step S220 in which the control unit 6 moves the welding robot 1 so that the first portion 221 of the welding nozzle 22 contacts the sensing mechanism 3, The first portion 221 can be obtained by obtaining the first nozzle coordinate (NP1, shown in FIG. 6) spaced from the center coordinate OP of the sensing hole 31 using the nozzle contact signal. The controller 6 controls the first direction 221 of the welding nozzle 22 inserted into the sensing hole 31 in the first direction (direction of arrow A) until the first portion 221 of the welding nozzle 22 contacts the sensing mechanism 3, The welding robot 1 is controlled so as to move in the opposite direction to the first direction (direction of the arrow A), in the opposite direction to the second direction (direction of the arrow B) and the second direction (direction of the arrow B) can do. The control unit 6 calculates the distance that the first portion 221 of the welding nozzle 22 inserted into the sensing hole 31 is spaced apart from the sensing mechanism 3 in four mutually perpendicular directions And the first nozzle coordinate information can be obtained by using the first nozzle coordinate information. The control unit 6 stores information such as the size of the sensing hole 31 and the center coordinates OP of the sensing hole 31. The control unit 6 controls the size of the sensing hole 31, the center coordinates OP of the sensing hole 31 and the first part 221 of the welding nozzle 22 in four perpendicular directions The first nozzle coordinate (NP1) can be obtained by performing an operation using a distance distanced from the sensing mechanism (3).

Next, the second portion 222 (shown in FIG. 7) of the welding nozzle 22 is inserted into the sensing hole 31 (S230). This step S230 may be performed by controlling the welding robot 1 such that the control portion 6 inserts the second portion 222 of the welding nozzle 22 into the sensing hole 31. [ The process S230 of inserting the second portion 222 of the welding nozzle 22 into the sensing hole 31 may be performed after the step S220 of obtaining the first nozzle coordinate information is completed, By moving the first part 221 of the welding nozzle 22 to the first nozzle coordinate NP1 and lowering the welding nozzle 22 by the reference height.

Next, the second nozzle coordinate information is obtained (S240). This step S240 is repeated until the control unit 6 moves the welding robot 1 so that the second portion 222 of the welding nozzle 22 comes into contact with the sensing mechanism 3, The second portion 222 can be obtained by obtaining a second nozzle coordinate (NP2, shown in FIG. 8) spaced from the center coordinate OP of the sensing hole 31 using a nozzle contact signal. The control unit 6 controls the first direction (arrow A direction), the second direction (the direction of arrow A) until the second portion 222 of the welding nozzle 22 inserted into the detection hole 31 contacts the sensing mechanism 3, The welding robot 1 is controlled so as to move in the opposite direction to the first direction (direction of the arrow A), in the opposite direction to the second direction (direction of the arrow B) and the second direction (direction of the arrow B) can do. The control unit 6 calculates the distance that the second portion 222 of the welding nozzle 22 inserted into the sensing hole 31 is spaced apart from the sensing mechanism 3 in four mutually perpendicular directions And the second nozzle coordinate information can be obtained by using the second nozzle coordinate information. The control unit 6 controls the size of the sensing hole 31, the center coordinates OP of the sensing hole 31 and the second portion 222 of the welding nozzle 22 in four perpendicular directions And the second nozzle coordinate (NP2) can be obtained by performing an operation using the distance distanced from the sensing mechanism (3).

Next, the welding nozzle 22 is set up in the vertical direction (S250). In this process (S250), the controller (6) derives the tilting information for the welding nozzle (22) from the first nozzle coordinate information and the second nozzle coordinate information, and outputs the tilting information And by controlling the welding robot 1 so that the nozzle 22 stands up in the vertical direction. The control unit 6 can derive the inclination information by performing an operation using the first nozzle coordinate NP1, the second nozzle coordinate NP2, and the reference height. The inclination information can be derived through the following operation.

First, the controller 6 derives a direction vector of the welding nozzle 22 connecting the two points using the first nozzle coordinate NP1 and the second nozzle coordinate NP2.

Next, the control unit 6 calculates an Included Angle (?) Existing between the direction vector of the welding nozzle 22 and the Z direction vector in the vertical direction by performing an operation according to the following Equation (1) .

Next, the controller 6 calculates the direction vector of the welding nozzle 22 and the Z direction vector with respect to the vertical direction according to the following equation (2) to calculate the direction vector of the welding nozzle 22 and the vertical direction The common normal Pn of the Z direction vector is derived.

Next, the control unit 6 rotates the welding nozzle 22 about the common normal line Pn derived from Equation (2) by the included angle (?) Derived from Equation (1) (22) can be vertically erected.

Referring to FIGS. 1 to 9, the step S200 of correcting the tilting of the welding nozzle 22 may further include the following steps.

First, the center coordinates (OP) of the sensing hole 31 are obtained by using the vertical welding nozzle 22 (S260). In this step S260, the control unit 6 sequentially moves the welding nozzles 22 in four mutually orthogonal directions after the welding nozzles 22 are set in the vertical direction, (OP) by using a nozzle contact signal generated by contact with the sensing mechanism (3). Accordingly, the welding torch deformation correcting method of the welding robot according to the present invention can correct the inclination correction for the welding nozzle 22 by checking whether or not the skew correction for the welding nozzle 22 has been performed correctly So that the occurrence of errors can be reduced.

Next, height information of the welding nozzle 22 is derived (S270). In this step S270, the control unit 6 places the welding nozzle 22 on the upper side of the sensing mechanism 3 and simultaneously places the welding wire 23 on the upper side of the sensing hole 31 By controlling the welding robot 1 so that the welding nozzle 22 is lowered. The control unit 6 can derive the height information of the welding nozzle 22 using the nozzle contact signal generated when the welding nozzle 22 is lowered and contacts the sensing mechanism 3. [

The step of placing the welding nozzle 22 on the upper side of the sensing mechanism 3 and positioning the welding wire 23 on the upper side of the sensing hole 31 is characterized in that the control part 6 is positioned in the vertical direction The welding robot 22 and the welding nozzle 22 are positioned at the center of the center coordinate OP so that the welding nozzle 22 moves at a short distance with respect to the radius of the sensing hole 31, Lt; / RTI > The control unit 6 calculates the welding nozzle 22 by using the diameter of the welding nozzle 22, the diameter of the welding wire 23 and the radius of the sensing hole 31, (22) is moved to position the welding wire (23) on the upper side of the detection hole (31), and the distance information The welding robot 1 can be controlled so that the welding nozzle 22 moves.

Next, the reference coordinates are obtained (S280). In this step S280, the control unit 6 determines whether the welding nozzle 22 erected in the vertical direction is spaced a predetermined distance from the center coordinate OP of the sensing hole 31 based on the derived height information And then acquiring a new reference coordinate for the welding nozzle 22. In this case,

Through the above-described processes, the welding torch deformation correcting method of the welding robot according to the present invention can complete the step (S200) of correcting the tilting of the welding nozzle 22. Accordingly, the welding torch deformation correcting method of the welding robot according to the present invention can prevent the quality of the workpiece from being lowered even if the welding nozzle 22 is deformed.

2, 9 and 10, a step S300 of inserting the welding wire 23 into the sensing hole 31 is performed by the control unit 6, (22) is lowered to a height at which the welding wire (23) is inserted into the sensing hole (31) in accordance with the derived height information while being positioned above the midpoint coordinate (OP) Can be achieved by controlling the welding robot (1). The control unit 6 performs the calculation using the length of the welding wire 23 and the height information so that the welding nozzle 22 is inserted to insert the welding wire 23 into the sensing hole 31 It is possible to obtain the descent distance to be lowered and to control the welding robot 1 so that the welding nozzle 22 descends according to the obtained descent distance.

Referring to FIG. 2 and FIG. 9 to FIG. 11, the step (S400) of obtaining the wire deformation information may include a step (S410) of obtaining wire coordinate information.

The control part 6 moves the welding robot 1 to detect the sensing part 231 of the welding wire 23 inserted into the sensing hole 31 11) from the center coordinates (OP, shown in Fig. 11) of the sensing hole 3, using the wire contact signal generated as the wire 3 is contacted with the sensing mechanism 3, And obtaining wire coordinate information. The sensing portion 231 refers to a portion of the welding wire 23 protruding from the welding nozzle 23 and spaced downward from the welding nozzle 22 by a predetermined distance. The sensing portion 231 may be preset by the user. The step of obtaining the wire coordinate information (S410) will be described in detail as follows.

First, the sensing portion 231 (shown in FIG. 11) is inserted into the sensing hole 31. Such a process may be performed by controlling the welding robot 1 such that the control portion 6 inserts the sensing portion 231 into the sensing hole 31. [ The step of inserting the sensing part 231 into the sensing hole 31 may be performed simultaneously with the step of inserting the welding wire 23 into the sensing hole 31 S300.

Next, the wire coordinate information for the sensing portion 231 is obtained. This process is carried out by the control unit 6 moving the welding robot 1 so that the sensing portion 231 is moved to the sensing portion 231 using a wire contact signal generated as the sensing portion 231 contacts the sensing mechanism 3. [ (WP, shown in FIG. 11), which is spaced apart from the midpoint coordinate OP of the sensing hole 31, as shown in FIG. The control unit 6 controls the sensor unit 3 in the first direction (A direction indicated by an arrow mark), the first direction (indicated by an arrow A direction) until the sensing unit 231 inserted into the sensing hole 31 contacts the sensing mechanism 3, (B arrow direction) and the second direction (B arrow direction), as shown in Fig. Accordingly, the control unit 6 derives the distance that the sensing portion 231 inserted into the sensing hole 31 is spaced apart from the sensing mechanism 3 in four mutually perpendicular directions, The wire coordinate information for the portion 231 can be obtained. The controller 6 controls the size of the sensing hole 31, the center coordinates OP of the sensing hole 31 and the sensing portion 231 from the sensing mechanism 3 in four perpendicular directions. The wire coordinate information (WP) can be obtained by performing an operation using a spaced distance.

Through the above-described processes, the welding torch deformation correcting method of the welding robot according to the present invention can complete the step (S410) of obtaining the wire coordinate information.

Referring to FIG. 2 and FIG. 9 to FIG. 11, the step (S400) of obtaining the wire deformation information may include a step (S420) of deriving the wire deformation information.

The step S420 of deriving the wire deformation information S420 may be performed by the control unit 6 deriving the wire deformation information from the nozzle coordinate information and the wire coordinate information. The control unit 6 compares the wire coordinate information for the sensing unit 231 and the coordinates (OP) of the center point of the sensing hole 31 obtained by using the vertical welding nozzle 22, The wire 23 can obtain deformed wire deformation information.

2 to 11, the welding torch deformation correcting method of the welding robot according to the present invention may further include a step (S500) of correcting deformation of the welding torch 2.

The step S500 of correcting the deformation of the welding torch 2 includes a step S510 of determining whether the wire deformation information is less than a predetermined range. This process (S510) may be performed by the control unit (6).

The step S500 of correcting the deformation of the welding torch 2 is a step of stopping the welding robot 1 and outputting a warning sound or warning message if it is determined that the wire deformation information is in a predetermined range or more S520). The process (S520) may be performed by the control unit (6).

The step S500 of correcting the deformation of the welding torch 2 includes a step S530 of correcting the reference coordinates of the welding torch 2 if the wire deformation information is less than a predetermined range. In this step S530, the control unit 6 determines that the welding nozzle 22 erected in the vertical direction is spaced a predetermined distance upward from the central coordinate OP of the sensing hole 31 based on the derived height information By obtaining the new reference coordinates for the welding nozzle 22 and correcting the reference coordinates set before the welding torch 2 has been deformed to the newly obtained reference coordinates have. Accordingly, the welding torch deformation correcting method of the welding robot according to the present invention can automatically correct deformation of the welding torch 2.

The step S530 of correcting the reference coordinates for the welding torch 2 is performed by the controller 6 so that the tool data for the welding torch 2 is reflected by the tilting and positional change of the welding nozzle 22, As shown in FIG. The step S530 of correcting the reference coordinates for the welding torch 2 may correct the tool data through the following process.

First, if the direction vector of the end of the welding torch 2 is R1 and the position vector of the end of the welding torch 2 is P1 before the welding torch 2 is deformed, Before the deformation occurs in the torch 2, the vector equation representing the state of the welding torch 2 is expressed by the following equation (3).

In Equation (3), TF1 is tool data on the state before the welding torch 2 is deformed, and is already stored in the control unit 6. [ Accordingly, the controller 6 can derive the transformation matrix TT1 for the state before the deformation occurs in the welding torch 2 through Equation (3).

Next, when a direction vector of the end of the welding torch 2 is defined as R2 and a positional vector of the end of the welding torch 2 is defined as P2 after the welding torch 2 is deformed, A vector expression representing the state of the welding torch 2 after deformation of the torch 2 is expressed by the following equation (4).

The control unit 6 calculates the position from the base coordinate system to the flange coordinate system of the welding robot 1 based on the tool data about the state before the deformation occurs in the welding torch 2 through Equation (4) Since the position derived by the calculation should be the same as R1 and P1 used in Equation (3), the tool data TT2 for the state where the deformation has occurred in the welding torch 2 can be calculated have.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Will be clear to those who have knowledge of.

100: Welding robot system 1: Welding robot
2: welding torch 3: sensing instrument
4: first signal generator 5: second signal generator
6: Control unit 31:

Claims (8)

Inserting a welding nozzle of a welding torch into a sensing hole formed in a sensing mechanism;
Moving the welding robot to correct the tilting of the welding nozzle so that the welding nozzle is vertically erected using a nozzle contact signal generated as the welding nozzle contacts the sensing mechanism;
Inserting a welding wire mounted on the welding nozzle into the sensing hole;
Moving the welding robot to obtain wire deformation information on the welding wire deformed by the welding wire with respect to the vertically oriented welding nozzle using a wire contact signal generated as the welding wire contacts the sensing mechanism; And
And correcting the deformation of the welding torch in accordance with the wire deformation information. The method according to claim 1,
The step of correcting the deformation with respect to the welding torch includes the step of obtaining deformation of the welding torch by obtaining reference coordinates for the vertically erected welding nozzle if the deformation of the wire is less than a predetermined reference range And the welding torch is deformed in the welding torch. The method of claim 1, wherein inserting the welding nozzle into the sensing hole
Lowering the welding nozzle by a predetermined distance;
Moving the welding nozzle in a first direction when the welding nozzle is lowered by a predetermined distance;
Moving the welding nozzle in a second direction perpendicular to the first direction after raising the welding nozzle by a predetermined distance if the nozzle contact signal and the wire contact signal are not received; And
Lowering the welding nozzle by a predetermined distance until the nozzle contact signal or the wire contact signal is received, moving the welding nozzle in the first direction, and raising the welding nozzle by a predetermined distance And then moving the welding torch in the second direction after the welding of the welding robot is performed. 2. The method of claim 1, wherein correcting the tilting of the welding nozzle comprises:
Wherein the welding robot moves the welding robot so that the first portion is spaced apart from the central coordinate of the sensing hole by using a first nozzle contact signal generated as the first portion of the welding nozzle inserted into the sensing hole contacts the sensing mechanism Obtaining first nozzle coordinate information;
Moving the welding robot so that the welding nozzle is lowered when the first nozzle coordinate information is obtained, thereby inserting a second portion of the welding nozzle spaced apart from the first portion into the sensing hole;
And a second nozzle contact signal generated as the second portion inserted into the detection hole is brought into contact with the sensing mechanism by moving the welding robot so that the second portion is spaced apart from the center coordinates of the sensing hole, Obtaining coordinate information; And
The welding nozzle is inclined with respect to the vertical direction from the first nozzle coordinate information and the second nozzle coordinate information and moves the welding robot according to the derived inclination information, And a step of erecting the welding torch in the vertical direction. The method according to claim 1,
The step of correcting the tilting of the welding nozzle comprises:
A step of moving the welding robot to acquire nozzle coordinate information of the welding nozzle spaced from the central coordinate of the sensing hole using a nozzle contact signal generated as the welding nozzle inserted into the sensing hole contacts the sensing mechanism ;
Positioning the welding nozzle on the upper side of the sensing mechanism by moving the welding robot according to the central coordinate and the nozzle coordinate information and positioning the welding wire on the upper side of the sensing hole; And
And moving the welding robot so that the welding nozzle is lowered to derive height information for the welding nozzle using a nozzle contact signal generated as the welding nozzle contacts the sensing mechanism
Wherein the step of correcting the deformation of the welding torch includes the step of correcting the reference coordinates set before obtaining the nozzle coordinate information to the reference coordinates obtained according to the nozzle coordinate information and the height information. Of welding torch. The method according to claim 1,
Wherein the step of correcting the tilting of the welding nozzle includes the step of moving the welding robot to move the welding nozzle to the center of the sensing hole using a nozzle contact signal generated as the welding nozzle inserted into the sensing hole contacts the sensing device, Obtaining nozzle coordinate information spaced from the coordinates;
Wherein the step of acquiring the wire deformation information further comprises the step of moving the welding robot so that the welding wire is moved to the center coordinate of the sensing ball by using a wire contact signal generated as the welding wire inserted into the sensing ball contacts the sensing mechanism And obtaining the wire deformation information from the nozzle coordinate information and the wire coordinate information. The welding torch deformation correcting method of a welding robot according to claim 1, wherein the wire deformation information is obtained from the nozzle coordinate information and the wire coordinate information. A welding robot including a welding torch and a robot arm for moving the welding torch, the welding robot performing a welding process;
A detection mechanism having a detection hole for inserting at least one of a welding nozzle and a welding wire of the welding torch;
A first signal generator connected to the welding nozzle and generating a nozzle contact signal when the welding nozzle contacts the sensing mechanism;
A second signal generator connected to the welding wire and generating a wire contact signal when the welding wire contacts the sensing mechanism; And
And a controller for correcting the tilting of the welding nozzle from the nozzle contact signal and the wire contact signal and controlling the welding robot to correct the deformation of the welding torch in accordance with the deformed wire deformation information Robot system. 8. The method of claim 7,
Wherein if the wire deformation information is less than a preset reference range, the control unit obtains reference coordinates for a welding nozzle set up in the vertical direction to correct deformation of the welding torch.

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