JP2014205154A - Control method for welding system and welding system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform automatic welding on a cylindrical body by achieving controlling elements that are necessary when performing welding such as welding speed and welding length, without requiring elements for actually measuring a diameter of the cylindrical body.SOLUTION: A welding system comprises: a pair of rotary rollers arranged at a predetermined interval; a motor for rotationally driving the rotary rollers; a cylindrical body placed on the rotary rollers; a manipulator having a welding torch for welding the cylindrical body; and a controller for performing control of the manipulator and the motor. The controller calculates rotational speed of the motor for rotating the cylindrical body at welding speed, on the basis of outer peripheral length of the rotary roller rotationally driven by the motor, a speed reduction ratio between the motor and the rotary roller rotationally driven by the motor and the preset welding speed. By rotating the motor at the rotational speed calculated by the controller, the cylindrical body is rotated at the preset welding speed, and the welding is performed by using the welding torch.

Description

  In the present invention, when a welding operation is performed on a welding line that is approximately on the circumference of a cylindrical or columnar object, the cylindrical or columnar object is rotated by a rotation axis that is approximately along the center line. The present invention relates to a welding system control method and welding system for automating a welding operation on a cylindrical or columnar object that is performed in a state where the welding torch is relatively moved on the target welding line.

  The circumferential welding operation of cylindrical objects such as tanks and pipes and columnar objects such as shafts (hereinafter collectively referred to as “cylindrical bodies”) involves rotating the cylindrical bodies. While doing so. In such welding work, the cylindrical body is mounted on a rotating jig configured by arranging a pair or plural pairs of rotating rollers arranged so that the rotation axes are parallel to each other at a predetermined interval. I often do work. This rotating jig is generally called a “turning roller” or a “turning roll”.

  The one or more pairs of rotating rollers contact and support the mounted cylindrical body on the outer peripheral surface thereof. Therefore, if one or a plurality of rotating rollers among the one or more pairs of rotating rollers is driven to rotate by a motor, the rotation can be transmitted from the rotating rollers to the cylindrical body, and the cylindrical body can be rotated. And if the welding torch for performing welding is held on the circumferential surface of the outer periphery or inner periphery of the cylindrical body, the cylindrical body is rotated by the above mechanism, thereby welding the circumferential welding line of the cylindrical body. The torch can be moved relatively. Thereby, welding work can be advanced, rotating a cylindrical body.

  In such a configuration, for example, when the outer periphery of a cylindrical body is to be circumferentially welded, conventionally, the procedure is as follows. First, the circumference length is obtained from the diameter of the cylinder to be welded. Further, the number of rotations of the motor necessary for one rotation of the cylindrical body is obtained from the reduction ratio of the reduction gear incorporated in the drive motor, the diameter of the rotating roller, and the like, and this is input to the motor control system. Thus, after the start of welding, when the motor rotates until it is determined that the cylindrical body has been rotated once or several times, the motor is stopped and the welding is stopped.

  When it is desired to accurately perform circumferential welding of the cylindrical body by this method, it is necessary to measure the diameter of the cylindrical body each time. In order to automate this actual measurement, the following method has been proposed (for example, see Patent Document 1).

  A “position scale” that contacts the outer peripheral surface of the cylindrical body and detects the contact position is disposed at a predetermined position away from any of the pair of rotating rollers that support the cylindrical body. While the position scale is in contact with the outer peripheral surface of the cylindrical body, one of the rotating rollers is driven to rotate by the motor to rotate the cylindrical body, and a welding torch disposed near the outer peripheral surface of the cylindrical body is attached. The welding is started by actuating, and the diameter of the cylindrical body is calculated based on the detected value by the above-mentioned position scale, the center position of the pair of turning rollers and the diameter thereof. Furthermore, the required rotational speed of the motor required to rotate the cylindrical body once is calculated from the calculated diameter, and the cumulative rotational speed of the motor counted from the start of welding to that time is calculated as the required rotational speed. When reaching a value multiplied by a predetermined number of circumferential weldings, the welding is stopped.

  In welding operations, the welding speed is an important factor that determines the result of the welding. If the diameter of the cylindrical body is known as described above, the circumference can be known. The circumference of the cylinder is the weld line length, and the rotation speed of the rotating roller required to obtain the desired welding speed is calculated from the required number of rotations of the motor and the weld line length required to rotate the cylinder once. can do.

Japanese Patent Laid-Open No. 7-80640

  In the welding method of the cylindrical body as described above, a “position scale” that contacts the outer peripheral surface of the cylindrical body and detects the contact position is arranged, which is necessary for welding such as the welding speed. A control element can be obtained. However, at least a “position scale” and a “mechanism for pressing the position scale against the cylindrical body” are necessary in order to use the “position surreal”.

  Here, as can be seen from the above description, in order to perform the welding operation while rotating the cylindrical body when simply welding the circumference of the cylindrical body, one or a plurality of rotations for mounting and rotating the cylindrical body is performed. A roller and a mechanism for placing the welding torch on the welding line of the cylindrical body are sufficient. Therefore, it can be said that the “position scale” and “mechanism for pressing the position scale against the cylindrical body” are elements that must be added to adopt the cylindrical body welding method as described above.

  In actual operation, reducing and simplifying the mechanism as much as possible is desirable not only for easy operation but also for improving maintainability by not increasing the number of failure elements. Therefore, it does not require any additional elements to measure the diameter of the cylinder, such as the conventional “position scale” and “mechanism for pressing the position scale against the cylinder”. If control elements required for welding, such as welding length, can be realized, it will be advantageous for use in the actual welding process.

  An object of the present invention is to provide a welding system control method and a welding system related to automation of welding to such a cylindrical body.

  In order to solve the above-described problem, a control method for a welding system according to the present invention includes a pair or a plurality of pairs of rotating rollers arranged so that the rotation axes are parallel to each other at a predetermined interval. A motor that rotationally drives one or more; a cylindrical body placed on the rotating roller; a manipulator having a welding torch for welding the cylindrical body; and a controller that controls the manipulator and the motor. A control method for a welding system, wherein the controller has a constant for obtaining an outer peripheral length or an outer peripheral length of the rotating roller rotated by the motor, and the rotating roller driven by the motor and the motor. Setting a reduction ratio and a welding speed between the controller and the controller. Calculating the rotation speed of the motor for rotating the cylindrical body at the welding speed based on the outer peripheral length of the rod, the reduction ratio, and the welding speed; and rotating the motor at the rotation speed calculated by the controller And rotating the cylindrical body at the set welding speed to perform welding using the welding torch.

  In addition to the above, the method for controlling the welding system of the present invention is such that the rotational speed of the motor for rotating the cylindrical body at a set welding speed is obtained by multiplying the welding speed by 2π, which is multiplied by the motor. It is calculated by dividing by the product of the outer peripheral length of the rotary roller that is rotationally driven and the reduction ratio between the motor and the rotary roller that is rotationally driven by the motor.

  Further, the welding system of the present invention includes a pair or a plurality of pairs of rotating rollers arranged so that the rotation axes are parallel to each other at a predetermined interval, and a motor that rotationally drives one or more of the rotating rollers. A cylinder mounted on the rotating roller; a manipulator having a welding torch for welding the cylinder; and a controller for controlling the manipulator and the motor, the controller being rotated by the motor Based on the outer peripheral length of the driven rotating roller, the reduction ratio between the motor and the rotating roller rotated by the motor, and the set welding speed, the cylindrical body is moved at the welding speed. Calculate the rotation speed of the motor for rotation, and rotate the motor at the rotation speed calculated by the controller. And it performs welding by using the welding torch the cylindrical body is rotated at the set welding speed by rolling.

  In the welding system of the present invention, in addition to the above, the rotational speed of the motor for rotating the cylindrical body at the set welding speed is obtained by multiplying the welding speed by 2π, which is rotated by the motor. It is calculated by dividing by the product of the outer peripheral length of the rotating roller and the reduction ratio between the motor and the rotating roller driven to rotate by the motor.

  As described above, according to the present invention, it is absolutely necessary to add an element that is unavoidably added to measure the diameter of the cylindrical body, such as the conventional “position scale” and “mechanism for pressing the position scale against the cylindrical body”. First, the welding system can be automated.

  Further, when the operator sets a welding speed which is one of the welding conditions, the controller determines the rotation speed of the motor for performing welding at the welding speed. And a cylindrical body can be rotated by the set welding speed by rotating a motor with the rotational speed of this motor. Therefore, it is not necessary for the operator to set the rotation speed of the motor himself, it is easy for the operator to set information on welding, and it is difficult to make mistakes, which is convenient for the operator.

  Moreover, even if cylinders with different diameters are mounted, the number of rotations of the rotating roller can be determined in order to weld at this welding speed based on the constant related to the rotating roller and the set welding speed. Welding at a set welding speed can be easily performed.

The figure which shows schematic structure of the welding system in embodiment of this invention. The figure which shows the example of the weld line in which the direction made into object in Embodiment 1 of this invention corresponds with the circumferential direction The figure which shows the example of the weld line from which the direction made into object in Embodiment 2 of this invention does not correspond with the circumferential direction The figure which shows the example in case the diameter of the cylindrical body made into object in Embodiment 3 of this invention is not constant.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. In the following, an example in which one of a pair of rotating rollers is rotationally driven by a motor will be described. However, the present invention does not limit the rotation of both rotating rollers by a motor. Further, when both rotating rollers are driven to rotate by a motor, it is considered that it is necessary to control the synchronization of the motors that drive both rotating rollers. However, this is a technical problem different from the present invention and is not described below.

  Furthermore, although the example which uses a pair of rotating roller is shown below, this invention does not restrict | limit using two or more rotating rollers. The number of rotating rollers used is not directly related to the present invention. In addition, if a cylindrical body becomes long, it will be necessary to support in several places, and it is natural that several pairs of rotating rollers are needed in that case. Therefore, it does not hinder the practice of the present invention.

(Embodiment 1)
FIG. 1 is a diagram showing a schematic configuration of a welding system in the present embodiment. In FIG. 1, the welding system includes a pair of rotating rollers 1 a and 1 b, a motor 2, a cylindrical body 3, a welding torch 4, a manipulator 5, and a controller 6.

  The rotation roller 1a and the rotation roller 1b, which are a pair of rotation rollers, are arranged so that the rotation axes are parallel to each other at a predetermined interval. The rotating roller 1a and the rotating roller 1b have the cylindrical body 3 mounted on their outer peripheral surfaces. The outer peripheral surface of the rotating roller 1 a and the outer peripheral surface of the rotating roller 1 b are in contact with the outer peripheral surface of the cylindrical body 3, and the rotating roller 1 a and the rotating roller 1 b support the cylindrical body 3.

  The motor 2 rotationally drives the rotating roller 1a which is one rotating roller. Although omitted in FIG. 1, actually, the rotational driving force of the motor 2 is transmitted to the rotating roller 1a via a transmission mechanism such as a speed reducer.

  The outer periphery of the cylindrical body 3 is in contact with the outer periphery of the rotating roller 1a. Therefore, when the rotating roller 1a rotates, the cylindrical body 3 also rotates. At this time, the peripheral speed of the outer periphery of the cylindrical body 3 substantially matches the peripheral speed of the outer periphery of the rotating roller 1a. Here, the reason described as “General” is that there is a possibility that there is a slight slip between the outer periphery of the cylindrical body 3 and the outer periphery of the rotating roller 1a. However, the effect of this slip can be ignored in the welding operation.

  The manipulator 5 is equipped with a welding torch 4, and positions the welding torch 4 at a position for welding a welding line (not shown) on the outer periphery of the cylindrical body 3, or welds in accordance with the welding line. Move the torch 4.

  The controller 6 drives a plurality of motors (not shown) that drive the joints constituting the motor 2 and the manipulator 5 and controls their operations. The controller 6 handles the rotating roller 1 a as an external shaft device that is driven by the motor 2. The term external shaft device here indicates an external shaft device other than the manipulator 5 controlled by the controller 6. That is, the controller 6 controls the rotating roller 1a as an external shaft device in addition to the manipulator 5. Furthermore, the controller 6 also controls a welding machine (not shown).

  Generally, in order to perform a welding operation using the manipulator 5, an external shaft device, a welding machine, or the like, it is necessary to prepare a program in the controller 6 in advance. In defining the operations of the manipulator 5 and the external shaft device, the program includes data representing the respective operation positions (hereinafter referred to as position) for each unit operation constituting the operation according to the operations of the manipulator 5 and the external shaft device. Data) is registered. The controller 6 moves each axis of the manipulator 5 and the external axis device according to the registered series of position data, thereby realizing a desired operation. In addition to this, designation information of welding conditions is registered in the program for performing the welding work. Here, the welding conditions include a welding current, a welding voltage, a welding speed, and the like. In addition, you may make it set these welding conditions to the controller 6 with the teaching apparatus etc. which are not shown in figure.

  There are various types of data used as position data. However, no matter which method is used, the basis is the rotational position of the motor that drives each axis of the manipulator 5 and the external shaft device. Here, the rotation position is determined as follows, for example. The motor of each axis has a reference state, and the angle at that time is set as a reference angle, and this is an amount of rotation for specifying how many rotations there are. This rotation amount is used as a rotation position. The position data is composed of data representing the rotational position of such a motor or data obtained by processing it.

  Using the rotational position of the motor 2 that drives the rotating roller 1a of the external shaft device, the outer peripheral position of the rotating roller 1a of the external shaft device can be expressed as follows. The outer peripheral position of the rotating roller 1a represents a displacement of the outer peripheral position of the rotating roller 1a from a certain state (for example, when the motor 2 is in a reference state).

P = Wσr (Formula 1)
Here, P is the displacement [mm] of the outer peripheral position of the rotating roller 1a. W is the outer peripheral length [mm] of the rotating roller 1a. σ is a reduction ratio between the motor 2 and the rotating roller 1a. r is the rotation position of the motor 2, that is, the rotation amount [number of rotations] from the reference angle of the motor 2. Thus, the displacement (outer peripheral position P) of the outer peripheral position of the rotating roller 1a can be expressed by an amount having a length dimension. That is, (Equation 1) is the relative displacement (outer peripheral position P) seen from the outside generated in the rotational direction of the outer peripheral surface of the rotating roller 1a by the rotational driving of the motor 2, and the motor 2 that drives the rotating roller 1a. The relationship with the rotation position r (rotation amount) is defined.

  As the position of the rotation roller 1a of the external shaft device registered in the program, the rotation position r of the motor 2 may be used, or the outer peripheral position P of the rotation roller 1a calculated therefrom may be used. May be used. In any method, the rotation position r of the motor 2 is the basis, so that the displacement (outer peripheral position P) of the outer peripheral position of the rotating roller 1a can be obtained from (Equation 1). The outer peripheral length W of the rotating roller 1a and the reduction ratio σ between the motor 2 and the rotating roller 1a are fixed values determined as a machine. Although not described here, it is assumed that a mechanism for setting these values is prepared. For example, these values are set in the controller 6 by a teaching device (not shown). Moreover, you may make it set the constant for calculating | requiring the outer peripheral length W of the rotating roller 1a, without setting the outer peripheral length W of the rotating roller 1a directly. Examples of the constant in this case include the diameter and radius of the rotating roller 1a. Based on the set diameter and radius of the rotating roller 1a, the controller 6 determines the outer peripheral length W of the rotating roller 1a.

  FIG. 2 shows an example in which the direction of the weld line on the outer periphery of the cylindrical body 3 coincides with the circumferential direction. In the case of FIG. 2, after positioning the welding torch 4 at the welding start position on the weld line, the manipulator 5 reaches the position where the welding torch 4 is located without moving the welding torch 4. By simply rotating the cylindrical body 3 to the right, the relative movement of the outer periphery of the cylindrical body 3 with respect to the welding torch 4 can be realized, and this can be used as a welding operation. The rotation of the cylindrical body 3 is generated by the rotation of the rotating roller 1a. The relative movement distance between the cylindrical body 3 and the welding torch 4 is the amount of movement of the outer periphery of the cylindrical body 3 due to the rotation of the cylindrical body 3, and corresponds to the amount of change in the outer peripheral position of the rotating roller 1a during this time. That is, it can be said that the difference between the outer peripheral position of the rotating roller 1a at the start of welding and the outer peripheral position of the rotating roller 1a at the end of welding is the welding length.

  Here, when a unit vector a in the tangential direction of the circumference of the cylindrical body 3 is introduced from the tip of the welding torch 4, a welding vector L1 representing a welding operation can be obtained as in (Equation 2).

L1 = (Pe1-Ps1) a (Formula 2)
Here, Pe1 is the outer peripheral position [mm] (rotation amount from the reference position) of the rotating roller 1a at the end of welding. Ps1 is the outer peripheral position [mm] of the rotating roller 1a at the start of welding. That is, (Equation 2) represents the relative displacement seen from the outside generated in the rotation direction of the outer peripheral surface of the rotating roller 1a.

  Therefore, from (Expression 1) and (Expression 2), the difference between Pe1 and Ps1 is obtained as follows.

(Pe1-Ps1) = Wσre1-Wσrs1 = Wσ (re1-rs1) (Formula 3)
Here, re1 is the rotational position (number of rotations) of the motor 2 at the end of welding. rs1 is the rotational position (number of rotations) of the motor 2 at the start of welding. (Equation 2) and (Equation 3) indicate that the motor 2 must rotate at the number of revolutions of (re1-rs1) in order to perform the operation of the welding vector L1. Conversely, if the motor 2 rotates at (re1-rs1), the welding vector L1 can be welded. The welding vector L1 can be said to be a one-dimensional vector whose direction is fixed in the circumferential direction. In the first embodiment, only the length of this vector, that is, the weld length is used. Note that the rotational position of the motor 2 at the start and end of welding can be known by the controller 6. Therefore, from the rotational position of the motor 2 at the start and end of welding, the outer peripheral length W of the rotating roller 1a, which is a fixed value, and the reduction ratio σ between the motor 2 and the rotating roller 1a, (Equation 2) Based on (Expression 3), the weld length can be obtained as the absolute value of the weld vector L1. The welding start position and the welding end position on the weld line of the cylindrical body 3 are specified by teaching performed before welding.

  If the welding speed is specified in the program, the required time between the welding length, that is, the absolute value of the welding vector L1 and the welding speed can be obtained. And if the rotation speed and required time of the motor 2 required for operation | movement are determined, the rotational speed of the motor 2 will be determined.

ω1 = 2π (re1-rs1) / T1 (Formula 4)
T1 = | L1 | / v (Formula 5)
Here, ω1 is the rotational speed [rad / s] of the motor 2. T1 is the required time [s]. v is the welding speed [mm / s] specified by the program.

  Then, based on (Expression 1) to (Expression 5), (Expression 4) becomes the following expression.

ω1 = 2πv / Wσ (Formula 6)
Therefore, the controller 6 can perform welding at a predetermined welding speed v by controlling the rotational speed of the motor 2 to the rotational speed ω <b> 1 of the motor 2. That is, when the operator sets the welding speed v, which is one of the welding conditions, the controller 6 determines the rotational speed ω1 of the motor 2 for performing welding at the welding speed v based on (Expression 6). The Then, by rotating the motor 2 at the rotation speed ω1 of the motor 2, the cylindrical body 3 can be rotated at the set welding speed v. Therefore, it is not necessary for the operator to set the rotation speed of the motor 2 that is not common in welding work, and it is only necessary to set a welding speed, which is one of general welding conditions, in the welding work. High nature.

  Thus, by setting the rotating roller 1 a as an external shaft device controlled by the controller 6, the external shaft device can be controlled simultaneously with the controller 6 in synchronization with the manipulator 5. And the relationship between the relative displacement seen from the outside produced in the rotation direction of the outer peripheral surface of the rotation roller 1a by the rotation drive of the motor 2 and the rotation amount of the motor 2 that drives the rotation roller 1a is defined (Equation 1) The section from the welding start position registered in the program to the welding end position can be programmed by using (Expression 2) that represents the relative displacement seen from the outside generated in the rotation direction of the outer peripheral surface of the rotating roller 1a. It becomes possible to perform welding at a specified welding speed. And the welding method of the cylindrical body 3 using the rotating roller 1a can be automated using the welding speed.

  Here, the description is based on the case where two position data from the start of welding to the end of welding are registered. However, if there is other registered position data between them, the method described above may be applied to the section between adjacent position data.

  Further, during the period from the start of welding to the end of welding, the entire circumference of the cylinder 3 may be welded by one rotation, or the partial welding may be performed in less than one rotation. Alternatively, during the period from the start of welding to the end of welding, the cylindrical body 3 may be rotated a plurality of times to perform multilayer welding. During this period, how many pieces of position data are registered is arbitrary, and the method described above may be applied to a section for each piece of adjacent position data.

  As described above, according to the present embodiment, elements that are unavoidably added to measure the diameter of the cylindrical body, such as the conventional “position scale” and “mechanism for pressing the position scale against the cylindrical body”, are necessary. Instead, the welding system can be automated.

  Further, when the operator sets the welding speed v which is one of the welding conditions, the controller 6 determines the rotational speed ω1 of the motor 2 for performing welding at the welding speed v. Then, by rotating the motor 2 at the rotation speed ω1 of the motor 2, the cylindrical body 3 can be rotated at the set welding speed v. Therefore, it is not necessary for the operator to set the rotation speed of the motor 2 himself, which is convenient for the operator.

(Embodiment 2)
In the present embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 3 shows a case where the weld line on the outer periphery of the cylindrical body 3 does not coincide with the circumferential direction. In the case of FIG. 3, the manipulator 5 moves the welding torch 4 not only in accordance with the rotation of the cylindrical body 3 but also in accordance with a welding line that moves in a direction perpendicular to the rotational direction of the cylindrical body 3 in accordance with the rotation of the cylindrical body 3. The operation is registered in the program. Thereby, the relative movement along the welding line of the welding torch 4 can be performed. The speed of this relative movement can be obtained as a combination of the peripheral speed of the outer periphery of the cylindrical body 3 and the moving speed of the manipulator 5 in the direction perpendicular thereto. Again, this relative movement speed during welding is the welding speed. Further, the relative moving distance is the welding length.

L2 = (Pe2-Ps2) a + (Xe2-Xs2) (Formula 7)
(Pe2-Ps2) = Wσre2-Wσrs2 = Wσ (re2-rs2) (Equation 8)
Here, a is a circumferential unit vector. L2 is a welding vector. Pe2 is the outer peripheral position of the rotating roller 1a at the end of welding. Ps2 is the outer peripheral position of the rotating roller 1a at the start of welding. Xe2 is a position vector of the welding torch 4 of the manipulator 5 at the end of welding. Xs2 is a position vector of the welding torch 4 of the manipulator 5 at the start of welding. re2 is the rotational position of the motor 2 at the end of welding. rs2 is the rotational position of the motor 2 at the start of welding.

  The first term and (Expression 8) in (Expression 7) are the same as those in Embodiment 1. The second term of (Expression 7) is a movement vector of the welding torch 4 by the manipulator 5. The position vector of the welding torch 4 can be calculated from the position data of the manipulator 5 registered in the program. Note that the calculation method is a technical element not directly related to the present invention, and thus description thereof is omitted here.

  Similar to the first embodiment, the required time can be obtained from the welding speed specified in the program and the welding length, that is, the absolute value of the welding vector L2. If the rotation speed and required time of the motor 2 necessary for the operation are determined, the rotation speed of the motor 2 is determined.

ω2 = 2π (re2-rs2) / T2 (Formula 9)
T2 = | L2 | / v (Formula 10)
Here, ω2 is the rotational speed [rad / s] of the motor 2. T2 is the required time [s]. v is the welding speed [mm / s] specified by the program. The controller 6 can perform welding at a predetermined welding speed v by controlling the rotational speed of the motor 2 to ω2.

  Thus, only the cylindrical body 3 is fixed by fixing the welding torch 4 by making the rotating roller 1a an external shaft device controlled by the controller 6 and having the outer peripheral length and the reduction ratio of the rotating roller 1a as fixed values. In the case where the welding torch 4 is moved in accordance with the rotation of the cylindrical body 3 as well as in the case of welding by rotating the welding body, the welding speed specified in the program is determined from the welding start to the welding end registered in the program. It becomes possible to perform welding. And the welding method of the cylindrical body 3 using the rotating roller 1a can be automated using the welding speed.

  Note that here, too, the explanation has been made based on the case where two position data from the start of welding to the end of welding are registered. The method described so far may be applied to the section.

(Embodiment 3)
In the present embodiment, the same parts as those in the first embodiment and the second embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The cylindrical body 3 is not necessarily a perfect circle. It is also assumed that it is distorted. In that case, the welding torch 4 must be moved up and down according to the irregularity of the cylindrical body 3. It is conceivable that the degree of vertical movement is measured in advance by a sensing function such as a touch sensor. In this case, in order to adjust to the irregularity, a plurality of position data is registered in the program between two position data from the start of welding to the end of welding, and each of them is measured by a sensing function. It is conceivable to correct the position individually.

  FIG. 4 shows a case where the diameter of the cylindrical body 3 is not constant. The cylindrical body 3 has a shift of D0 when rotated by 0 degrees and 360 degrees, a shift of D1 when rotated by 90 degrees, and a shift of D2 when rotated by 180 degrees, and 270 degrees. A state where there is a deviation of D3 is shown in the rotated position.

  Assuming that the position data is registered every 90 degrees, sensing is performed at each position, the deviation from D0 to D3 is measured, and the result is reflected in each position data. The welding operation using the corrected position data can be performed by the method shown in the second embodiment.

(Embodiment 4)
In the present embodiment, the same portions as those in the first to third embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

  In order to perform weaving welding by the manipulator 5, it is necessary to generate a weaving motion vector. In order to generate a weaving motion vector, the direction of the weld line is required. Further, in order to control the weaving pitch or the weaving frequency, a welding speed is required. As described in the first embodiment, the second embodiment, and the third embodiment, in the present invention, the direction of the weld line is determined, and the cylindrical body 3 can be rotated at the welding speed. It is possible to cause the manipulator 5 to perform a weaving operation.

  In addition, since it is a well-known technical element about how to implement | achieve a weaving operation | movement using the direction and welding speed of a weld line, description here is abbreviate | omitted.

  According to the present embodiment, since the weaving can also be performed in the welding system shown in FIG. 1, the position correction by the arc sensor can also be performed.

(Embodiment 5)
In the present embodiment, the same parts as those in the first to fourth embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

  The manipulator 5 has a function of shifting registered position data with reference to the weld line direction, and is frequently used. Of course, in order to use this function, the weld line direction is required. As described in the first embodiment, the second embodiment, the third embodiment, and the fourth embodiment, in the present invention, since the direction of the weld line is calculated, the weld line direction is used as a reference. It is possible to use a function for shifting registered position data.

  In addition, since it is a well-known technical element about how to shift the position data registered on the basis of the weld line direction, explanation here is omitted.

(Embodiment 6)
In the present embodiment, the same parts as those in the first to fifth embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

  The welding speed described in the first embodiment corresponds to the peripheral speed of the outer periphery of the cylindrical body 3. And the peripheral speed of the outer periphery of the cylindrical body 3 is a peripheral speed of the outer periphery of the rotating roller 1a. The relationship between the peripheral speed of the outer periphery of the rotating roller 1a and the rotational speed of the motor 2 can be expressed by the following equation.

v = Rω (Formula 11)
Here, v is the designated welding speed [mm / s]. R is the radius [mm] of the rotating roller 1a. ω is the rotational speed [rad / s] of the motor 2. From this equation, if the welding speed is specified, the rotational speed of the motor 2 can be calculated. If the rotational speed of the rotating roller 1a is known, the motor 2 can be controlled with this as a target. The radius R of the rotating roller 1a is a fixed value and is set in advance.

  By utilizing this, it is possible to control to perform welding at a predetermined welding speed. Welding while operating instead of the teaching pre-back type position-to-position control as described in the first embodiment, the second embodiment, the third embodiment, the fourth embodiment, or the fifth embodiment. It is possible to control such as a dedicated machine. For example, the welding torch 4 is fixed to some jig without using the manipulator 5, and when the operator instructs the start of welding, the cylindrical body 3 rotates to perform welding, and when the operator instructs the stop of the welding, the cylindrical body 3 It is also possible to perform a dedicated machine control in which the rotation of the steel stops and the welding ends.

  According to the present invention, when automating a cylindrical body welding method using a rotating roller, welding conditions can be designated at a welding speed originally necessary for welding without making an operator aware of the number of rotations and the rotating speed of the rotating roller. Therefore, even if cylindrical bodies having different diameters are mounted, the welding conditions can be easily applied, and the present invention is industrially useful as a control method and welding system for a welding system that performs welding while rotating the cylindrical body.

DESCRIPTION OF SYMBOLS 1a Rotating roller 1b Rotating roller 2 Motor 3 Cylindrical body 4 Welding torch 5 Manipulator 6 Controller a Unit vector L Welding vector L1 Welding vector L2 Welding vector P Outer peripheral position Pe1 Outer position Ps1 Outer position Pe2 Outer position Ps2 Outer position W Peripheral length R Radius of rotating roller 1a σ Reduction ratio between motor 2 and rotating roller 1a r Rotating position of motor 2 re1 Rotating position of motor 2 at end of welding rs1 Rotating position of motor 2 at start of welding T1 Required time T2 Required time ω1 Motor 2 rotational speed ω2 Motor 2 rotational speed v Welding speed Xe2 Position vector Xs2 Position vector

Claims (4)

A pair or a plurality of pairs of rotating rollers arranged so that the rotation axes are parallel to each other at a predetermined interval, a motor that rotationally drives one or more of the rotating rollers, and a motor mounted on the rotating roller A control method of a welding system comprising a cylindrical body, a manipulator having a welding torch for welding the cylindrical body, and a controller for controlling the manipulator and the motor,
A constant for obtaining the outer peripheral length or outer peripheral length of the rotating roller rotated by the motor in the controller, a reduction ratio between the motor and the rotating roller rotated by the motor, and a welding speed A step for setting and
The controller calculating a rotational speed of the motor for rotating the cylindrical body at the welding speed based on an outer peripheral length of the rotating roller, the reduction ratio, and the welding speed;
Rotating the cylindrical body at the set welding speed by rotating the motor at the rotation speed calculated by the controller, and performing welding using the welding torch;
A method for controlling a welding system comprising: The rotation speed of the motor for rotating the cylindrical body at a set welding speed is obtained by multiplying the welding speed by 2π, and rotating this by the outer peripheral length of a rotating roller driven by the motor, the motor and the motor. The method of controlling a welding system according to claim 1, wherein the method is calculated by dividing by a product of a reduction ratio with the driven rotating roller. A pair or a plurality of pairs of rotating rollers arranged so that the rotation axes are parallel to each other at a predetermined interval;
A motor that rotationally drives one or more of the rotating rollers;
A cylindrical body placed on the rotating roller;
A manipulator having a welding torch for welding the cylindrical body;
A controller for controlling the manipulator and the motor,
The controller is based on the outer peripheral length of the rotating roller rotated by the motor, the reduction ratio between the motor and the rotating roller rotated by the motor, and the set welding speed. Calculating the rotational speed of the motor for rotating the cylindrical body at the welding speed;
A welding system for performing welding using the welding torch by rotating the cylindrical body at the set welding speed by rotating the motor at a rotation speed calculated by the controller. The rotation speed of the motor for rotating the cylindrical body at a set welding speed is obtained by multiplying the welding speed by 2π, and rotating this by the outer peripheral length of a rotating roller driven by the motor, the motor and the motor. The welding system according to claim 3, wherein the welding system is calculated by dividing by a product of a reduction ratio with the driven rotating roller.

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