KR100952660B1 - Automatic welding apparatus and welding method - Google Patents

Abstract

PURPOSE: An automatic welding device and an automatic welding method are provided to watch the distance variation between a welding rod and a weld line in real time using a sensor installation unit extended from one side of a carriage. CONSTITUTION: An automatic welding method using an automatic welding device comprises the following steps: installing a rail(180) of the automatic welding device(100) around the outer circumference of a steel pipe; locating a carriage(110) on the rail and locating a welding rod(150) on the lower side of a joint; measuring a gap on the joint by moving the carriage and saving; setting a welding condition at a location where the gab is minimum; setting the welding condition at a location where the gab is maximum; and operating the automatic welding device.

Description

Automatic welding apparatus and welding method therefor {automatic welding apparatus and welding method}

The present invention relates to an automatic welding device and an automatic welding method thereof, and more particularly, to allow automatic welding even when a gap spaced in a direction perpendicular to the axis center is formed in a joint portion between two steel pipes for welding, The present invention relates to an automatic welding device capable of simply welding steel pipes having different specifications and an automatic welding method thereof.

In general, when a change or branching direction is required when piping using steel pipes, separate curved pipes or straight pipes are used, and the curved pipes and straight pipes are welded to the steel pipes.

In this case, when the diameters of the pipes to be welded to each other are large, the joints of the pipes are welded by using an existing automatic welding device, and both of the pipes to be welded in this way are possible only at the butt welding in which their ends are joined flat to each other. .

In the automatic welding of a pipe by such a conventional automatic welding device, a rail is circumferentially installed on one side of the pipe, a carriage is installed on the rail, and a welding rod provided on the carriage is positioned on the joint of the pipe. Is driven on the rail and moves along the circumferential direction of the tube to weld the seam of the butt welded tube.

However, in the conventional automatic welding device for welding the joints of the butt joint pipes, the welding position of the welding rod provided in the carriage is set once before welding, so that the position of the welding rod cannot be adjusted during the welding process. In the case where the gap is formed in the direction of the center of the pipe joint of the small inner tube inserted into the larger diameter of the outer tube), the automatic welding device cannot be re-adjusted and it is not possible to weld. There was a downside.

That is, since the gap formed between the inner tube and the outer surface is not constant and diversified, it is impossible to weld with the automatic welding device, and there is an inconvenience in that the worker must weld by hand.

The present invention has been made to solve the problems of the prior art as described above, the insertion form by configuring the position and width of the electrode initially set in the carriage of the automatic welding device can be adjusted during the welding process according to the input welding conditions It is an object of the present invention to provide an automatic welding device and an automatic welding method for welding a joint of a pipe quickly and easily even when gaps are generated due to different diameters of pipe joints.

An object of the present invention as described above, in the automatic welding device for welding the joint portion of the steel pipe with a gap spaced in the direction perpendicular to the axial direction between the inner pipe and the outer surface, the automatic welding device, the outer peripheral surface of the steel pipe A rail installed in the circumferential direction; A carriage having a welding rod movably installed on the rail and welded at one side thereof to weld a joint of a steel pipe; An oscillator for weaving the electrode; A transfer device for moving the welding rod in a direction parallel to a direction parallel to the steel pipe; A position tracking encoder installed to be interlocked with the drive motor output shaft of the carriage to measure a travel distance of the carriage moved on the rail, and to determine the current position of the welding machine using the distance measurement value; A sensor mount extending from the carriage in an end direction of the exterior; First and second sensing means mounted on the sensor mounting table to measure distances between the inner tube and the outer surface and to compare the respective measured values to inspect gaps formed at the joints of the steel pipes; And a welding line sensing unit mounted on the sensor mounting table to measure an X-axis separation distance between the welding rod and the welding line to maintain a constant distance between the welding rod and the welding line.

The conveying apparatus includes an X-axis conveying apparatus configured to move the welding rod in a direction parallel to the steel pipe, the X-axis conveying apparatus comprising: a main body installed on the carriage and having a pinion gear; A rack gear part movable to the main body and engaged with the pinion gear; And a motor installed in the main body to drive the pinion gear.

In addition, it is preferable that a speed reducer is provided between the motor and the pinion gear to reduce the power of the motor and transmit the power to the pinion gear.

The conveying apparatus includes a Y-axis conveying apparatus configured to move the welding rod in a direction perpendicular to the steel pipe, wherein the Y-axis conveying apparatus includes a main body having a pinion gear installed at right angles to the rack gear part of the X-axis conveying apparatus. ; A rack gear unit which is movable to the main body and meshes with the pinion gear, and an oscillator is installed at one side thereof; And a motor installed in the main body to drive the pinion gear.

Here, the reducer may be installed between the motor and the pinion gear to reduce the power of the motor and transmit the deceleration to the pinion gear.

The oscillator may include a weaving shaft to which a welding rod is connected; A ring cage to which the weaving shaft is fixed; An oscillation motor for rotating the link cage; A pivot shaft to which the link cage is rotatably coupled and moved on the link cage; A screw shaft which is screwed through the peel shaft and has a driven gear installed at one end thereof; And a motor for rotationally driving the drive gear engaged with the driven gear, and a speed reducer is provided between the oscillation motor and the ring cage to decelerate the power of the oscillation motor and transmit it to the ring cage.

In addition, the weaving width of the electrode is determined by the following equation according to the gap size of the joint.

[Equation]

Coefficient of increase of weaving width =

The sensor mounting bracket is provided with a sensor mounting bracket, so that the sensor mounting bracket is coupled to one side of the carriage using a connecting rod that can be adjusted in length.

The first and second sensing means are respectively mounted on the outer wall of the sensor mounting bracket, the first sensing means is located on the upper side of the inner tube relative to the welding line, the second sensing means is located on the outer side In each case, the distance change values for the inner tube and the outer tube are measured.

In this case, the first and second sensing means may use an optical sensor.

The welding line detection unit, the housing is installed on the inner wall of the sensor mounting bracket provided on the sensor mounting table and opened to the bottom; A rotary lever coupled to the inside of the housing in a state where the upper end is axially rotatable in the X-axis direction and the lower end extending toward the welding line; A spherical bearing coupled to the lower end of the rotary lever and rotated in contact with an external end of the welding line; An elastic means installed at an upper end of the rotary lever so that the spherical bearing is always in close contact with the appearance of the welding line; And a potentiometer connected to the upper end rotation shaft of the rotation lever to measure a rotation angle of the rotation lever to sense a change in distance between the electrode and the welding line.

On the other hand, an object of the present invention as described above, by using the automatic welding device configured as described above as an automatic welding method for welding the joints of the steel pipe with a gap spaced in the direction perpendicular to the axial direction between the inner tube and the outer surface, Installing a rail of the automatic welding device in the circumferential direction on the outer circumferential surface of the steel pipe and installing a carriage on the rail while positioning the welding rod at the lower end, that is, the starting point of the joint; Moving the carriage on the rail to measure and store the gap on the seam; Moving the carriage to a position where the gap is minimum and setting a welding condition at that position; Moving the carriage to a position where the gap is maximum and setting a welding condition at that position; It is achieved by an automatic welding method comprising a; moving the carriage to the starting point of the joint and operating by welding the automatic welding device.

In the step of welding the joint of the steel pipe by operating the automatic welding device, the weaving width of the electrode is determined by the following equation according to the gap size of the joint.

[Equation]

Coefficient of increase of weaving width =

The welding condition includes a distance between the end of the electrode and the end surface of the outer appearance, the distance between the end of the electrode and the outer surface of the inner tube, the weaving width of the electrode, the weaving speed, and the traveling speed of the carriage.

According to the automatic welding device of the present invention and the automatic welding method thereof, the welding rod of the automatic welding device which is moved along the outer circumferential surface of the exterior according to the gap formed between the inner tube to be welded and the joint of the exterior is adjusted by filling the gap of the joint Regardless of steel pipe sizes of various diameters, it is possible to weld quickly and easily.

In addition, according to the present invention, the position tracking encoder for measuring the distance traveled on the driving motor side of the carriage, and the distance to each of the inner tube and the exterior on the sensor mounting table extending to one side of the carriage to enable By providing the second sensing means and comparing the respective measured values, the weldability can be improved by accurately grasping the size and position of the gap formed between the inner pipe to be welded and the joint of the outer face.

In addition, according to the present invention, by installing a welding wire detection unit that can monitor the distance change between the welding wire and the welding rod in real time by using a sensor mounting rod extending to one side of the carriage, there is an effect that welding failure is prevented.

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

1 to 8b are views illustrating an automatic welding device and an automatic welding method thereof according to the present invention.

The automatic welding device 100 according to the present invention is a device for welding a joint of a steel pipe having a gap 30 spaced in a direction perpendicular to the axial direction between the inner tube 10 and the outer tube 20.

The automatic welding device 100, as shown in Figure 1, the rail 180 is installed in the circumferential direction on the outer circumferential surface of the steel pipe, and installed on the rail 180 to be movable and weaving of the steel pipe while weaving on one side thereof A carriage 110 having a welding rod 150 for welding parts, an oscillator 140 for weaving the welding rod 150, and the oscillator 140, that is, the welding rod 150, in a direction parallel to the steel pipe; It has a conveying device for moving in the Y-axis direction perpendicular to the steel pipe.

In addition, the automatic welding device 100 according to the present invention is installed to interlock with the drive motor output shaft of the carriage 110, to measure the traveling distance of the carriage 110 moved on the rail 180, the distance The encoder further includes a position tracking encoder 210 to determine the current position of the welder using the measured value.

In addition, the sensor mounting unit 220 extending from the carriage 110 in the direction of the outer end of the installation, and mounted on the sensor mounting unit 220 and the distance between the inner tube 10 and the outer 20, respectively, and measure the respective It further comprises a first, second sensing means 250, 260 for comparing the values and inspecting the gap formed in the joint of the steel pipe.

In addition, the sensor mounting unit 220 further includes a welding line sensor 270 for measuring the distance between the welding rod 150 and the welding line in the X-axis direction to maintain a constant distance between the welding rod 150 and the welding line. .

Here, the rail 180 is installed on the outer circumferential surface of the steel pipe, as shown in Figure 1, more preferably is installed in the circumferential direction on the outer circumferential surface of the inner pipe (10).

The rail 180 installed as described above is attached to the outer circumferential surface of the inner tube 10 via a permanent magnet (not shown), and the permanent magnet is controlled by the magnet controller 190.

Accordingly, the rail 180 may be attached or fixed to the outer circumferential surface of the inner tube 10 according to whether the magnetic force of the permanent magnet controlled by the magnet controller 190 is generated.

And, the carriage 110 is installed on the rail 180 is moved along the rail 180, one side of the carriage 110 to operate the carriage 110 and the transfer device, the oscillator 140 to be described later The controller 111 for controlling is installed.

Here, although not shown in the drawing, the sprocket wheel is rotatably installed at the center of the lower surface of the carriage 110, and the rotating wheel is sequentially inserted into a plurality of holes drilled in a straight line at the center of the rail 180. While moving the carriage 110.

In addition, a driving motor (not shown) is installed inside the carriage 110 to rotate the wheel, and guide rollers (not shown) are inserted and guided at both ends of the rail 180 at both ends of the carriage 110. Is further configured.

In addition, the front end of the carriage 110 adjusts the position of the welding rod 150 by moving the welding rod 150, that is, the oscillator 140, in a direction perpendicular to the direction parallel to the steel pipe according to the size of the gap 30. A conveying apparatus is configured, and the conveying apparatus is composed of an X-axis conveying apparatus 120 and a Y-axis conveying apparatus 130 as shown in FIGS. 1 and 2.

As shown in FIG. 2, the X-axis feeder 120 is fixed to the front end of the carriage 110 in a transverse direction, that is, in a horizontal direction, and has a pinion gear 123 rotatably installed at the center of the bottom thereof. The rack 122 and the pinion gear 123 and the pinion gear 123 and the main body 122, which is installed to be movable to the main body 122, are installed in the main body 122 to drive the pinion gear 123 It is configured to include a motor 125 consisting of a step motor, the speed reducer 124 to reduce the power of the motor 125 to the pinion gear 123 between the motor 125 and the pinion gear 123 is further Is installed.

The X-axis feeder 120 configured as described above has a rack gear part engaged with the pinion gear 123 while the pinion gear 123 of the main body 122 is decelerated and driven by the reducer 124 when the motor 125 is driven. Linear reciprocating movement of the 121 to the left and right on the body 122, and by the linear reciprocating motion of the X-axis feeder 120, the Y-axis feeder 130 to be described later also makes a linear reciprocating motion to the left and right.

As shown in FIG. 2, the Y-axis feeder 130 is different from the X-axis feeder 120 only in the installation direction, and its configuration is largely the same.

That is, the Y-axis feeder 130 is installed at right angles to the rack gear portion 121 of the X-axis feeder 120, and a main body 132 having a pinion gear 133 rotatably installed at the center thereof. And a rack gear unit 131 installed on the main body 132 and being engaged with the pinion gear 133 and having an oscillator 140 installed on one side thereof, and installed on the main body 132. It comprises a motor 135 made of a step motor for driving the gear 133, and between the motor 135 and the pinion gear 133 decelerates the power of the motor 135 to be transmitted to the pinion gear 133. Reducer 134 is further installed.

The Y-axis feeder 130 is a rack gear unit 131 meshed with the pinion gear 133 while the pinion gear 133 of the main body 132 is decelerated and driven by the reducer 134 when the motor 135 is driven. ) Linear reciprocating back and forth on the main body 132, the oscillator 140 to be described later is a linear reciprocating back and forth by the linear reciprocating motion of the Y-axis feeder 130.

Here, although the speed reducer 124 and 134 are not shown in the present embodiment, in order to reduce the power of the motor 125 and 135, the speed reducer 124 and 134 may be configured by a conventional link means or gear means.

Therefore, the position of the welding rod 150 can be adjusted as shown in FIGS. 5A and 5B according to the variable width of the gap 30 by the operation of the transfer apparatus 120 or 130 as described above, and the oscillator to be described later. The weaving width of the welding rod 150 at that position is determined by 140.

In addition, the oscillator 140, as shown in Figure 3a, consists of an oscillation unit and an adjusting unit for adjusting the weaving width.

The oscillation unit is a configuration of a conventional oscillator 140 for weaving the welding rod 150, the welding rod 150 is connected to the installation of the weaving shaft 146, and the weaving shaft 146 fixed ring cage ( 147, an oscillation motor 149 that rotates the link cage 147, and a linkage between the motor 149 and the ring cage 147 to decelerate the power of the oscillation motor 149 And reducer 148 to 147.

Here, the oscillation motor 149 is composed of a forward and reverse rotation motor, and although not shown, the oscillation motor 149 is configured with a link means or a gear means, and pendulum the linkage 147 like a clock pendulum. Preferably configured to exercise.

The weaving width adjusting portion is a portion for adjusting the weaving width of the welding rod 150 according to the size of the gap 30, the ring cage 147 is rotatably coupled with the pivot that is moved on the ring cage 147 A shaft 145, a screw shaft 144 which is screwed through the pivot shaft 145 and has a driven gear 143 installed at one end thereof, and a drive gear 142 meshed with the driven gear 143. It includes a motor 141 consisting of a step motor for driving rotation.

Accordingly, the ring cage 147 rotates the pivot shaft 145 about its axis, and the pivot shaft 145 is moved up and down on the ring cage 147 so that the position of the rotation axis, that is, the hinge point, is changed to the weaving width. Adjusted.

3b and 3c, the weaving width transmitted to the welding rod 150 by the ring cage 147 when the pivot shaft 145 reaches the highest point on the ring cage 147 is illustrated in FIG. 3c shows the weaving width transmitted to the welding rod 150 by the ring cage 147 when the pivot shaft 145 reaches the lowest point on the ring cage. It can be seen that the weaving width is determined according to the position of 147).

And, the weaving width of the welding rod 150 weaving by the oscillator 140 is determined by the following equation according to the gap 30 size, that is, the width (distance) of the groove.

[Equation]

Coefficient of increase of weaving width =

That is, as can be seen in the above equation, the functional relationship between the weaving width and the gap 30 is welded the joint of the steel pipe while the weaving width increases by 1.414213562 mm each time the gap 30 is increased by 1 mm.

Moreover, as the weaving width is increased as described above, the weaving speed and the traveling speed of the carriage 110 are preferably lowered at a constant ratio.

In this way, the amount of the gap 30 according to the position is measured with respect to the entire length of the joint of the steel pipe.

Here, reference numeral 170 denotes a CO 2 welder.

Therefore, the automatic welding device 100 sets the respective welding conditions at the position where the gap 30 of the joint is minimum and the maximum, and the welding conditions are the end and the appearance 20 of the electrode 150. Distance (x) from the end surface of the (), the distance (y) of the end of the welding rod 150 and the outer surface of the inner tube 10, the weaving width (ww), the weaving speed (ws), the carriage of the welding rod 150 Travel speed ts of 110.

9 is an enlarged view illustrating main parts of a sensor mounting structure of the automatic welding device according to the present invention.

The sensor mounting bracket 220 as shown in the figure is provided with a sensor mounting bracket 230, the sensor mounting bracket 230 on the carriage 110 using a connection rod 240 is adjustable in length To be combined.

At this time, the connecting rod 240 is coupled to the two tubes slidable with each other, one end of the base rod 241 is fixedly coupled to the carriage 110 side, the other end of the base rod 241 slides in the inner diameter The rod 243 is inserted and slides in the longitudinal direction.

Here, a fixing member 245 is formed at the outer diameter of the base rod 241, and the fixing member 245 is slid through the base rod 241 by pressing the slide rod 243 by screwing. Will be limited.

That is, adjusting the length of the slide rod 243 in a state in which the screwing of the fixing member 245 is released, and after the proper length is adjusted, the fixing member 245 is screwed so that the length is maintained. do.

At this time, the base rod 241 and the slide rod 243 may be a square or cylindrical rod.

The first and second sensing means 250 and 260 measure the distance by irradiating light toward the center of the tube and analyzing a current value depending on the intensity of the reflected light, and thus measuring the distance and the reference distance. The gap 30 is measured and stored by calculating and the like.

The first and second sensing means 250 and 260 are respectively mounted on the outer wall of the sensor mounting bracket, but the first sensing means 250 is positioned on the inner tube 10 side based on the welding line. The second sensing means 260 is positioned at the upper side of the exterior 20 side, and each of them measures a distance change value for the inner tube 10 and the exterior 20.

As such, the reason for installing the first and second sensing means 250 and 260, respectively, is to constantly measure the gap between the inner tube 10 and the exterior 20.

If only one sensing means is installed, the welding machine rotates along the outer circumference of the steel pipe, and the welding work is performed at various positions such as upper welding, upward vertical welding, and lower welding. In the vertical welding process, the gap between the welder main body and the steel pipe may be generated by gravity, which may cause a problem in which the gap measurement values do not coincide. The present invention overcomes the error and the first and second sensing By comparatively comparing the measured values of the means 250 and 260, it is possible to always obtain a constant measured value.

Here, if the method of sensing the gap is formulated, it can be expressed as a gap = measurement distance B-(measurement distance A + thickness of the exterior) as shown in FIG.

The first and second sensing means 250 and 260 may use an optical sensor.

10 is a schematic diagram showing an operation state of the welding line detection unit of the automatic welding device according to the present invention.

The welding line detecting unit 270 is provided on the inner wall 231 of the sensor mounting bracket 230 provided in the sensor mounting unit 220, and has a housing 271 that is open downward.

In addition, an upper end of the rotary lever 273 is coupled to the inside of the housing 271 so as to be axially rotatable in the X-axis direction, and a lower end extends toward the welding line.

At this time, the spherical bearing 273 is coupled to the lower end of the rotary lever 273 in a rotatable state, the spherical bearing 273 is rotated in contact with the welding line, that is, the outer end 20, the carriage 110 ) Will move in the direction of travel.

An elastic means 274 is installed at the upper end of the rotary lever 272 so that the spherical bearing 273 is always in close contact with the appearance of the welding line.

Such elastic means 274 may be used a spring member for elastically supporting both upper ends of the rotary lever 272.

In addition, a potentiometer 275 is connected to the upper end rotation shaft of the rotary lever 272 to measure a rotation angle of the rotary lever 272 to detect a change in distance between the welding rod and the welding line.

(Explanation of welding method below)

On the other hand, by using the automatic welding device 100 configured as described above automatic welding method for welding the joint of the steel pipe formed with the gap 30 spaced in the direction perpendicular to the axial direction between the inner tube 10 and the exterior 20. Is, including the installation step, the gap measurement step, the first and second setting step, the welding step.

The installation step, the rail 180 of the automatic welding device 100 on the outer circumferential surface of the inner tube 10 of the steel pipe in the circumferential direction and install the carriage 110 on the rail 180 while welding rod 150 Is positioned at the start of the joint.

At this time, the starting point is the lower end of the joint portion due to the nature of the welding, the end point is the upper end of the joint portion, it is possible to weld without being interrupted by the flow of the welding liquid generated during welding.

And, the automatic welding device 100 is installed on the rail 180 is installed in two to run in the opposite direction with a time difference from the starting point.

In the gap measuring step, the distance between the inner tube 10 and the exterior 20 is measured through the first and second sensing means 250 and 260 while driving the carriage 110 on the rail 180 installed as described above. It measures and compares each measured value, and examines the gap 30 formed in the joint part of a steel pipe.

The primary setting step includes moving the carriage 110 to a position where the gap 30 of the joint is minimum and setting a minimum condition of welding at the position, and the secondary setting step includes a gap of the joint part. It consists of moving the carriage 110 to the position at which the 30 is the maximum and setting the maximum condition of the welding at that position.

Here, the welding condition is the distance (xi) (xf) between the end of the electrode 150 and the end surface of the outer appearance 20, the distance (yi) of the end of the electrode 150 and the outer surface of the inner tube 10 (yi) (yf), the weaving width (wwi) (wwf) of the welding rod 150, the weaving speed (wsi) (wsf), and the traveling speed (tsi) (tsf) of the carriage 110.

Therefore, the minimum condition of the welding means that the values of the above conditions are minimum, and the maximum condition of the welding means that the values of the above conditions are maximum.

In addition, the welding step includes moving the carriage 110 to the lower end of the joint, that is, the starting point, and then operating the welding device 100 to weld the carriage 110.

At this time, the weaving width of the welding rod 150 configured in the automatic welding device 100 is determined by the following equation according to the gap 30 size, that is, the width (distance) of the joint.

[Equation]

Coefficient of increase of weaving width =

As can be seen from the above equation, the functional relationship between the weaving width and the gap 30 is that each time the gap 30 is increased by 1 mm, the weaving width is increased by 1.414213562 mm, welding the joint of the steel pipe, and the weaving speed and the carriage at this time The running speed is programmed to decrease at a constant rate as the weaving width increases.

Therefore, when the automatic welding device 100 welds the joint while moving from the start point of the joint to the end of the steel pipe, the coordinates (x) (y) of the welding rod 150 according to the size of the variable gap 30, Weaving width (ww), weaving speed (ws) and the running speed (ts) of the carriage 110 is automatically adjusted while automatically welding.

Hereinafter, the operation and automatic welding process of the automatic welding device according to the present invention configured as described above.

First, the rail 180 is circumferentially installed on the outer circumferential surface of the inner tube 10 of the steel pipe to be welded through the permanent magnet, and the two carriages 110 can run in opposite directions on the rail 180. Put it on and install it.

Then, the carriage 110 is moved to position the welding rod 150 installed on the carriage 110 at the start point of the joint, and then the carriage 110 is driven at the starting point, respectively, by the sensor 160 to the inner tube 10 and the exterior ( The size of the gap 30 formed between the 20 is measured to store the information of the gap 30.

According to the information of the gap 30 stored in this way, the distance (xi) between the end of the welding rod 150 and the end surface of the appearance 20 at the position where the gap 30 of the joint is minimum, the end of the welding rod 150 And welding conditions such as distance (yi) from the outer surface of the inner tube (10), the weaving width (wwi) of the welding rod (150), the weaving speed (wsi), and the traveling speed (tsi) of the carriage 110 are set to minimum values. After that, the welding condition as described above is set to the maximum value at the position where the gap 30 of the joint is maximum.

Thereafter, the carriage 110 is moved to the lower end of the joint, that is, the starting point, and then the two carriages 110 are operated at a time difference, respectively, thereby automatically welding the joint.

At this time, the coordinates and the weaving width of the welding rod 150 are automatically adjusted by the X-axis and Y-axis feeder 120, 130 and the oscillator 140 according to the size of the gap 30 that varies from the start point to the end point of the joint. do.

That is, when the motor 125 of the X-axis feeder 120 is driven by the controller 111 according to the size of the gap 30, the pinion gear 123 of the main body 122 is decelerated by the reducer 124. By linearly reciprocating the Y-axis feeder 130, the oscillator 140, and the welding rod 150 in the X-axis direction by moving the rack gear 121 engaged with the pinion gear 123 from side to side on the body 122 while being driven. Exercised.

Then, when the motor 135 of the Y-axis feeder 130 is driven, the pinion gear 133 of the main body 132 is decelerated by the reducer 134 while being engaged with the pinion gear 133 (the rack gear part) By moving the 131 back and forth on the main body 132, the oscillator 140 and the welding rod 150 are linearly reciprocated in the Y-axis direction.

Therefore, the coordinates of the electrode 150 is adjusted by the X-axis and Y-axis feeder 120, 130 as shown in Figures 5a and 5b.

In addition, when the motor 141 of the oscillator 140 is driven, the drive gear 142 and the driven gear 143 engaged therewith are driven to rotate, and the screw shaft 144 integrally formed with the driven gear 143 is rotated. do.

Then, as the pivot shaft 145 screwed to the screw shaft 144 is moved up and down, the hinge point of the ring cage 147 is changed, and the hinge cage is changed so that the top of the ring cage 147 is changed. The ice width will be different.

Therefore, the weaving width of the welding rod 150 connected to the weaving shaft 146 of the ring cage 147 is adjusted according to the coordinates of the welding rod 150, and according to the coordinates of the welding rod 150 (that is, the size of the gap 30). As the weaving width, the coefficient of the weaving width is increased as the size of the gap 30 is increased by the following equation.

[Equation]

Coefficient of increase of weaving width =

Therefore, when the automatic welding device 100 welds the joint while moving from the start point of the joint of the steel pipe to the end point, the weaving width and the weaving speed of the welding rod 150 and the carriage 110 according to the size of the variable gap 30. The driving speed of auto adjusts automatically.

On the other hand, the connection pattern of the steel pipe that is automatically welded by the automatic welding device 100, that is, the inner tube 10 and the exterior 20 as described above, as shown in Figures 6a to 8b, a total of six cases All six such cases are automatically welded by the above-described automatic welding method according to the present invention.

6A and 6B, in the case of the pattern in which the inner tube 10 is connected to the left or right side of the inside of the exterior 20, the two automatic welding apparatuses 100 installed at the lower end of the joint, that is, the starting point, are described above. According to the automatic welding method of the present invention, the joint is automatically welded.

At this time, as can be seen in the figure and the graph of Figure 6, in the case of the pattern 1, the automatic welding device 100 starts welding at the position where the gap 30 is the largest, the gap 30 is the most at the intermediate point This is the case where the gap 30 becomes the maximum at a small end point. At this time, the weaving speed and the traveling speed of the automatic welding device 100 start at the slowest and proceed at the highest speed in the middle point, and at the end point again at the highest slow speed. Weld

In addition, as can be seen from the diagram and the graph of Figure 6b, in the case of the pattern 2, the automatic welding device 100 starts welding at the position where the gap 30 is the smallest, the gap 30 at the intermediate point is the most This is the case where the gap 30 becomes the minimum at the end of the big, and at this time, the weaving speed and the traveling speed of the automatic welding device 100 start at the highest speed, progress at the highest speed at the middle point, and at the highest speed again at the end point. Weld

As shown in FIGS. 7A and 7B, in the case of a pattern in which the inner tube 10 is connected to the upper side or the lower side of the inside of the exterior 20, the two automatic welding apparatuses 100 installed at the lower end of the joint, that is, the starting point, are described above. According to the automatic welding method of the present invention, the joint is automatically welded.

And, as can be seen in the diagram and the graph of Figure 7a, in the case of the pattern 3, the automatic welding device 100 starts and welds at the position where the gap 30 is the largest, the gap 30 is the minimum at the end point In this case, the weaving speed and the running speed of the automatic welding device 100 is welded at the highest speed at the highest start and end point.

As can be seen from the diagram and graph of FIG. 7B, in the case of pattern 4, when the automatic welding apparatus 100 starts and welds at the position where the gap 30 is the smallest, the gap 30 becomes maximum at the end point. At this time, the weaving speed and the traveling speed of the automatic welding device 100 is welded at the highest speed at the highest starting point and ending point.

As shown in FIGS. 8A and 8B, in the case of a pattern in which the inner tube 10 is connected in an inclined direction to the inside of the exterior 20, the two automatic welding apparatuses 100 installed at the lower end of the joint, that is, the starting point, are described above. According to the automatic welding method of the present invention, the joint is automatically welded.

And, as can be seen in the diagram and graph of Figure 8a, in the case of the pattern 5, the automatic welding apparatus 100 starts and welds at the position where the gap 30 is the smallest, and the gap (before the end point, that is, the 45 degree direction ( The gap 30 gradually decreases to the point where the maximum value is 30), and then the weaving speed and the traveling speed of the automatic welding device 100 start at the highest speed and become the slowest speed before the end point. We will finish welding at a faster rate.

As can be seen from the diagram and graph of FIG. 8B, in the case of pattern 6, the automatic welding device 100 starts and welds at a position where the gap 30 is slightly present, and the gap 30 becomes the minimum and ends. In this case, the gap 30 becomes the maximum, and the weaving speed and the running speed of the automatic welding device 100 start slightly slower and gradually become slower to the point where the gap 30 becomes the fastest at the minimum and ends. At the end of the process, the welding ends at the slowest speed.

1 is a block diagram of an automatic welding device according to the present invention.

2 is a view showing the X-axis and Y-axis feeder of the automatic welding device according to the invention.

Figure 3 is a view showing the oscillator of the automatic welding apparatus according to the present invention, Figure 3a is a configuration diagram of the oscillator, Figure 3b and Figure 3c is a view showing the weaving width of the oscillator, respectively.

Figure 4 is a view showing a sensing process of the automatic welding device according to the present invention.

5 is a view showing an automatic welding process of the automatic welding apparatus according to the present invention, Figure 5a is a view showing a case where the gap of the pipe connecting to the minimum, Figure 5b is a case where the gap of the pipe connecting to the maximum. Figure.

Figures 6a to 8b is a view showing a graph of the connection pattern of the pipe and the corresponding welding conditions for explaining the automatic welding method of the automatic welding apparatus according to the present invention.

Figure 9 is an enlarged view of the main portion showing the structure of the sensor mounting table of the automatic welding apparatus according to the present invention.

10 is a schematic diagram showing an operation state of the welding line detection unit of the automatic welding device according to the present invention.

<Description of the symbols for the main parts of the drawings>

10: inner tube 20: appearance

30: gap 100: automatic welding device

110: carriage 111: controller

120,130: X-axis and Y-axis feeder 121,131: Rack gear part

122,132: main body 123,133: pinion gear

124,134: Reducer 125,135: Motor

140: oscillator 141: motor

142: drive gear 143: driven gear

144: screw shaft 145: pivot shaft

146: weaving shaft 147: linkage cage

148: reducer 149: oscillation motor

150: welding rod 160: sensor

170: welder 180: rail

190: magnet controller 210: encoder for position tracking

220: sensor mounting bracket 230: mounting bracket for the sensor

231: outer wall 233: inner wall

240: connecting rod 241: base rod

243: slide bar 245: fixing member

250: first sensing means 260: second sensing means

270: weld wire detection unit 271: housing

272: rotating lever 273: spherical bearing

274: elastic means 275: potentiometer

xi = minimum distance between the end of the electrode and the end of the facade

yi is the minimum distance between the end of the electrode and the outer surface of the inner tube

wwi: minimum weaving width

wsi: minimum weaving speed

tsi: minimum driving speed

xf: maximum distance between the end of the electrode and the end of the facade

yf: maximum distance between the end of the welding rod and the outer surface of the inner tube

wwf: Maximum weaving width

wsf: Maximum weaving speed

tsf: Maximum driving speed

Claims (15)

In the automatic welding device for welding the joints of the steel pipe with a gap spaced in the direction perpendicular to the axial direction between the inner pipe and the outer pipe, The automatic welding device, the rail is installed in the circumferential direction on the outer peripheral surface of the steel pipe; A carriage having a welding rod movably installed on the rail and welded at one side thereof to weld a joint of a steel pipe; An oscillator for weaving the electrode; A transfer device for moving the welding rod in a direction parallel to a direction parallel to the steel pipe; A position tracking encoder installed to be interlocked with the drive motor output shaft of the carriage to measure a travel distance of the carriage moved on the rail, and to determine the current position of the welding machine using the distance measurement value; A sensor mount extending from the carriage in an end direction of the exterior; First and second sensing means mounted on the sensor mounting table to measure distances between the inner tube and the outer face and compare the respective measured values to inspect gaps formed at the joints of the steel pipes; And A welding line detection unit mounted on the sensor mounting base to measure a distance in the X-axis direction between the welding rod and the welding line to maintain a constant distance between the welding rod and the welding line; Automatic welding device, characterized in that configured to include. The method of claim 1, The conveying device is configured with an X-axis conveying device for moving the welding rod in a direction parallel to the steel pipe, The X-axis feeder, the main body is installed in the carriage and has a pinion gear; A rack gear part movable to the main body and engaged with the pinion gear; And a motor installed at the main body to drive the pinion gear. The method of claim 2, Between the motor and the pinion gear automatic welding device, characterized in that the reduction gear for reducing the power of the motor to transmit to the pinion gear. The method of claim 2, The transfer device, the Y-axis transfer device for moving the welding rod in the direction perpendicular to the steel pipe is configured, The Y-axis feeder includes: a main body installed at right angles to the rack gear portion of the X-axis feeder and having a pinion gear; A rack gear unit which is movable to the main body and meshes with the pinion gear, and an oscillator is installed at one side thereof; And a motor installed at the main body to drive the pinion gear. The method of claim 4, wherein Between the motor and the pinion gear automatic welding device, characterized in that the reduction gear for reducing the power of the motor to transmit to the pinion gear. The method of claim 1, The oscillator may include a weaving shaft to which a welding rod is connected; A ring cage to which the weaving shaft is fixed; An oscillation motor for rotating the link cage; A pivot shaft to which the link cage is rotatably coupled and moved on the link cage; A screw shaft screwed through the pivot shaft and having a driven gear installed at one end thereof; And a motor for rotationally driving the drive gear engaged with the driven gear. The method of claim 6, An automatic welding device between the oscillation motor and the ring cage is provided with a reducer for reducing the power of the oscillation motor and transmitting it to the ring cage. The method of claim 1, Weaving width of the electrode is an automatic welding device, characterized in that determined by the following equation according to the gap size of the joint. [Equation] Coefficient of increase of weaving width =

The method of claim 1, The sensor mounting bracket is provided with a sensor mounting bracket, the automatic welding device, characterized in that the sensor mounting bracket to be coupled to one side of the carriage using a length adjustable connection rod. The method of claim 1, The first and second sensing means are respectively mounted on the outer wall of the sensor mounting bracket, the first sensing means is located on the upper side of the inner tube relative to the welding line, the second sensing means is located on the outer side Automatic welding apparatus, characterized in that for measuring the distance change value for the inner tube and the exterior. The method of claim 10, The first and second sensing means is an automatic welding device, characterized in that the optical sensor. The method of claim 1, The welding line detection unit, the housing is installed on the inner wall of the sensor mounting bracket provided on the sensor mounting table and opened to the bottom; A rotary lever coupled to the inside of the housing in a state where the upper end is axially rotatable in the X-axis direction and the lower end extending toward the welding line; A spherical bearing coupled to the lower end of the rotary lever and rotated in contact with an external end of the welding line; An elastic means installed at an upper end of the rotary lever so that the spherical bearing is always in close contact with the appearance of the welding line; And A potentiometer connected to an upper end rotation shaft of the rotation lever to measure a rotation angle of the rotation lever to detect a change in distance between the welding rod and the welding line; Automatic welding device comprising a. An automatic welding method for welding a joint portion of a steel pipe having a gap spaced in a direction perpendicular to the axial direction between an inner tube and an outer surface by using an automatic welding device as set forth in any one of claims 1 to 12, Installing a rail of the automatic welding device in the circumferential direction on the outer circumferential surface of the steel pipe and installing a carriage on the rail while positioning the welding rod at the lower end, that is, the starting point of the joint; Moving the carriage on the rail to measure and store the gap on the seam; Moving the carriage to a position where the gap is minimum and setting a welding condition at that position; Moving the carriage to a position where the gap is maximum and setting a welding condition at that position; And moving the carriage to the starting point of the joint to operate the automatic welding device for welding. The method of claim 13, In the step of welding the joint of the steel pipe by operating the automatic welding device, the welding width of the welding rod is an automatic welding method, characterized in that determined by the following equation according to the gap size of the joint. [Equation] Coefficient of increase of weaving width =

The method of claim 13, The welding conditions include the distance between the end of the electrode and the end surface of the external appearance, the distance between the end of the electrode and the outer surface of the inner tube, the weaving width of the welding rod, the weaving speed, the traveling speed of the carriage. Way.

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