KR101175541B1 - Railless automatic steel pipe welding device - Google Patents

Abstract

PURPOSE: An automatic railless steel pipe welding apparatus is provided to implement welding in an accurate position by securing a welding torch in the center of a joint even if a steel pipe has a bent shape or the distance between edges changes. CONSTITUTION: An automatic railless steel pipe welding apparatus comprises a box-shaped body(10), a driving unit(20) which is fitted and transferred on the surface of a steel pipe by a magnetic force, a welding torch(30) which is arranged in the body and installed above a joint, a sensing unit(40) which obtains the positions of edges of the steel pipe and connects the edges with straight lines to secure a welding zone, a data processing unit which divides the width of the welding zone to obtain a welding track, and a traveling control unit(60) which controls the driving unit to regulate the traveling direction so that the welding track is aligned to the center are of the sensing unit.

Description

Railless Automatic Steel Pipe Welding Device

The present invention relates to an automatic welding device for a railless steel pipe, and more specifically, to detect the ends of two steel pipes to be connected without installing a rail, and to determine the moving direction and the welding position according to the result, to automatically manufacture the steel pipe. The present invention relates to a railless automatic welding device for welding with steel.

The steel pipes are manufactured to have a certain length, and the installation site connects and installs the steel pipes of the predetermined length as needed. In this case, a separate connector is used to connect the steel pipes, or a pair of steel pipes face each other. The method of joining the parts by welding is used.

However, in the case of large diameter steel pipes, it is difficult to connect them using a connector, etc., and therefore, steel pipes are mainly connected by welding. When connecting large diameter steel pipes by welding, a rail is installed on the outer circumferential surface of the steel pipe. In the case of installing the rail on the outer circumferential surface of the steel pipe as described above, the process of dismantling and then dismantling the rail for each welding position has a disadvantage in that it takes considerable time and cost.

In order to solve the problems caused by the recent rail installation, instead of installing the rail on the outer circumferential surface of the steel pipe, instead of using the magnetic force of the railless automatic welding device that allows the welder to perform welding while moving along the outer circumferential surface of the steel pipe This railless automatic welding device is a separate welding machine movement guide means for welding in the correct position in place of the rail because the rail for guiding the movement of the welding machine is not installed on the outer peripheral surface of the steel pipe As a result, research on an automatic welding device having a welding machine movement guide means has been actively conducted.

An example of an automatic welding device having a welding machine movement guide means is a steel pipe automatic welding device disclosed in Patent No. 1037114, which discloses an inner surface of a steel pipe using magnetic force as shown in FIG. 1. Or a traveling part 100 moving in contact with the outer surface; A welding part 200 provided at one side of the driving part 100 to perform a welding operation while moving along a welding trajectory; A pair of sensing units 300 provided at both left and right sides of the welding unit 200 to contact the steel pipe to move the welding unit 200 along the welding trajectory through contact information; It is provided on one side of the driving unit 100 includes a control unit for controlling the driving unit 100 and the welding unit 200 by using the sensing information of the sensing unit 300, the sensing unit 300 is in contact with the steel pipe It consists of a contact displacement sensor that detects a change in the length of the generated end, where the contact displacement sensor is a welding rod that is scattered during welding even though the sensor rod must be drawn in or out according to the depth of the end contacting the steel pipe. By attaching to the outer surface of the sensor rod, the draw-out operation of the sensor rod is not smooth. As a result, the welding device is not moved correctly along the welding trajectory due to the malfunction of the contact displacement sensor, and as a result, the welding is not performed at the correct position. there is a problem.

Another example is the automatic welding apparatus disclosed in Patent Nos. 1082633 and 1157014. The welding apparatus disclosed in these documents detects the tip of a steel pipe using a laser sensor, and welds based on the detected tip. After the trajectory has been established, the welding is performed automatically by moving the welding device along the weld trajectory.

However, the welding apparatus described in these documents is characterized in that the movement (welding trajectory) of the welding apparatus is made only by detecting the tip of one of the pair of steel pipes, depending on the detected result, so that the end of the steel pipe is not round or welded. When the width of the part where the steel pipe and the steel pipe are joined together, ie, the width of the joint, changes, the weld trajectory is not kept constant along the joint, such that welding is performed at an unnecessary position. It is inconvenient to remove the wrong welding place and perform the welding work again.

The present invention has been made to solve the problems of the conventional automatic welding device as described above, it is possible to perform welding automatically by accurately setting the moving direction and welding position while moving along the outer circumferential surface of the steel pipe without installing a rail The aim is to provide an automatic welding device for a railless steel pipe.

An object of the present invention as described above is a railless automatic welding device, the main body of the enclosure shape; A driving unit installed on a bottom surface of the main body and being in close contact with the surface of the steel pipe by magnetic force; A welding torch provided in the main body and installed at an upper portion of the joint part; A sensing unit provided in the driving unit and detecting edges of both sides of the steel pipe to acquire positions of x _{1_1} and x _{2_1} , respectively, and connecting the straight lines to obtain a welding area; A data processor for acquiring a welding trajectory by dividing the width of the welding region obtained through the sensing unit; It is achieved by including a traveling control unit for adjusting the driving direction by controlling the drive unit so that the weld trajectory and the central region of the sensing unit coincide with each other.

In this case, a total of four driving wheels are installed in the driving unit, one pair of left and right sides, and a pair of driving wheels positioned forward and backward among the four driving wheels are driven at a constant speed. The traveling speed of the driving wheel is configured to be variable, and the traveling control unit may be implemented by adjusting the traveling direction of the main body by adjusting the traveling speed of the front and rear drive wheels of the pair.

And a spacing controller may be further provided to maintain a constant distance between the welding torch and the joint.

On the other hand, obtained by adding x _{2_ 2} coordinates to follow the edge of one side of steel pipe in the sensing unit, and the virtual straight line connecting the x _{1_ 1-coordinate} and the x _{2_ 1} coordinates in the reference line, the x _{1_ 1-coordinate} Determines whether an imaginary straight line connecting the x _{2_ 1} coordinate is perpendicular to the reference line, and an angle formed by the imaginary straight line connecting the reference line with the x _{1_1} coordinate and the x _{2_1} coordinate is not 90 °. In this case, the x _{1_ 1} coordinate may be reacquired, and in the vertical case, an imaginary straight line connecting the x _{1_ 1} coordinate and the x _{2_ 1} coordinate may be obtained as the welding region.

In addition, the interval adjusting unit and the horizontal rail is installed on the main body; A moving block sliding along the horizontal rail; A vertical rail installed on the moving block and having a vertical length; The railless automatic welding device, characterized in that it comprises a movable block installed on the vertical rail to move up and down.

According to the present invention, after detecting the edges formed in the joints of the steel pipes connected to each other using a laser sensor, the distance between them is calculated, and using the calculated distance value by the virtual center line of the steel pipe joints Since the welding trajectory is acquired to adjust the direction of movement of the welder body to move the welding torch along the welding trajectory, the welding torch can always be located at the center of the joint even if there is a bend in the steel pipe or the distance between the edges is changed. This can be done in the correct position without biasing to one side.

In addition, the present invention can greatly reduce the defect of welding using the automatic railless welding device, there is an advantage that can be quickly welded steel pipe by a simple installation.

1 is a perspective view showing an example of a conventional railless automatic welding device,
Figure 2 is a perspective view showing an example of a railless automatic welding device according to the present invention,
FIG. 3 is an exploded perspective view of FIG. 2,
Figure 4 is a bottom perspective view showing an example of the main body and the drive unit according to the present invention,
5 is a perspective view showing a welding torch and a gap control unit according to the present invention;
6 is a perspective view showing an example in which a welding apparatus according to the present invention is installed in a steel pipe,
7 (a, b) and 8 are a cross-sectional view and a plan view showing an example of obtaining the width and weld trajectory of the weld zone of the steel pipe joint according to the present invention;
9 is a configuration diagram showing an example of the automatic welding device of the railless steel pipe according to the present invention,
Figure 10 (a, b) is a use state showing the operation of the interval adjusting unit according to the present invention,
11 and 12 are a side view and a plan view showing an example in which the welding apparatus according to the present invention is installed in a steel pipe.

Hereinafter, the configuration of the present invention through the accompanying drawings showing a preferred embodiment will be described in more detail.

The present invention is to provide a rail-free automatic welding device that can weld the joint of the steel pipe while the welding device moves along the outer circumferential surface of the steel pipe without installing a rail on the outer peripheral surface of the steel pipe, the present invention for this purpose As shown in FIG. 2 and FIG. 3, a main body 10, a driving unit 20, a welding torch 30, a sensing unit 40, a data processing unit 50, and a traveling control unit 60 are included.

The main body 10 is formed in a rectangular box shape, and a driving unit 20, a data processing unit 50, and a traveling control unit 60, which will be described later, are accommodated therein, and on one side, a user sets a welding condition or a work situation. It is provided with a display for monitoring.

At this time, the lower portion of the main body 10 is in an open state, and as shown in FIG. 4, the driving unit 20 for moving the welding device 2 by the driving of the motor is installed in the open space under the main body 10. In addition, four driving wheels 21, 22, 23, and 24 are installed in the driving unit 20, one pair installed on the left and right sides, and thus the main body 10 includes four driving wheels 21, 22, 23, 24 is moved along the outer circumferential surface of the steel pipe, wherein the main body 10 is moved in contact with the outer circumferential surface of the steel pipe by the magnetic force generated by the magnetic force generating unit to be described later.

And the side of the main body 10 is installed so that the welding torch 30 and the sensing unit 40 to be described later to the outside of the main body 10, whereby the welding torch 30 and the sensing unit 40 is the main body 10 It moves along) to maintain a constant distance from the steel pipe.

The drive unit 20 installed on the bottom of the main body 10 includes a magnetic force generating unit for generating a magnetic force, thereby maintaining the state in which the driving unit 20 is in close contact with the surface of the steel pipe by magnetic force, and as a result, the outer peripheral surface of the steel pipe. The main body 10 is driven along the outer circumferential surface of the steel pipe by four driving wheels 21, 22, 23, and 24 driven by a motor of the driving unit 20, without installing a rail for guiding the traveling of the main body 10. The welding is performed while moving to 360 °.

The magnetic force generating portion is composed of an electromagnet in which the magnitude of the input current is adjusted, whereby the strength of the magnetic field is varied by varying the current input to the electromagnet, so that the main body 10 moves along the surface of the steel pipe or is separated from the steel pipe. Can be.

In addition, the four driving wheels 21, 22, 23, and 24 of the driving unit 20 are configured to control the traveling speed by the control of the driving control unit 50, which will be described later, and thereby the driving direction of the main body 10. This is adjusted, a detailed description thereof will be described later.

The welding torch 30 attached to the main body 10 and installed so as to be exposed to the side of the main body 10 is the main body by a gap adjusting unit 70 or a separate fixing bar to be described later, as shown in FIGS. 5 and 6. It is fixed to (10), for this purpose is provided with a torch clamp 31 for fixing the welding torch (30) long, detachable.

And the welding torch 30 is selected from the well-known ones which are generally widely used.

The sensing unit 40, which is installed on the side of the main body 10 and is located on the same line as the welding torch 30 and is installed on the upper part of the joint of the steel pipe, is formed of one or two laser sensors. ), The driving direction of the main body 10 is determined according to the detection result of the sensing unit 40, and steering is controlled. As a result, the welding torch 30 is always a virtual center line (welding) of the steel pipe joint. The welding is performed while moving along the track (c)).

In this case, the edge of the steel pipe generally forms a chamfer at each end of the steel pipe to be connected so as to flatten the welded surface when welding the steel pipe by welding, and to facilitate the welding operation. The sensing unit 40 of the present invention detects these two edges simultaneously. And a seam refers to a chamfer formed between these two edges.

The laser sensor is composed of a transmitter for generating a laser, a detector for detecting a laser reflected back from a target, and a counter for calculating a flight time of the laser to emit the laser from the emitter. Next, as a principle of measuring the distance by measuring the time taken for the laser to return from the target (the surface of the steel pipe) and returning, the laser sensor used in the present invention is generally used in a measuring device or the like. Since the configuration, operation principle, and installation method of the laser sensor are well known, detailed description thereof will be omitted.

The sensing unit 40 detects two edges by using a laser sensor of the sensing unit 40 to radiate a laser in a portion where the ends of the pair of steel pipes meet each other, that is, near the joint, for welding connection. After receiving and analyzing the returned reflected wave, as shown in FIG. 7, the positions of the two edges, that is, the position of x _{1_1 and} the position of x _{2_1} can be detected, respectively, and the positions x _{1_1} and x _{2_1} of these edges are detected. When connected in a straight line, the width (w) of the region to be welded can be calculated. If the width (w) of the welding region is divided into two, the welding trajectory (c) is performed while the end center of the welding torch is followed. .

However, even if the positions of the two edges are detected by the sensing unit 40 as described above, the position accuracy of x _{1_1} and x _{2_1} detected when the widths of the joints of the steel pipes are different or the edges of the steel pipes are not parallel to each other and are inclined. Depending on the welding trajectory (c) and the actual position to be welded may be a fine error.

Accordingly, in the present invention, it is determined whether a virtual straight line connecting the detected x _{1_1} and x _{2_1} is parallel to a line (hereinafter referred to as an “edge line”) connecting the edges of the steel pipe as a reference, and correcting this. By doing so, it is possible to more accurately estimate the weld trajectory c.

To do this, a virtual straight line that detects the position of x _{1_1} and x _{2_1} and follows the edge line of the reference steel pipe (for example, the steel pipe first connected by welding when several steel pipes are connected by welding) is detected. In order to obtain, the position of x _{2_2} is further detected and obtained as shown in FIG. 8, and a virtual straight line connecting the previously detected x _{2_1} position and x _{2_2} position to each other is set as the reference line r.

In addition, the angle formed by an imaginary straight line connecting the reference line r and x _{1_1} and x _{2_1} to each other is obtained. When the angle formed is vertical (90 °), it means that x _{1_1} and x _{2_1} are correctly obtained. , Greater than or equal to 90 ° means that the position of x _{1_1} is incorrectly detected.

In this case, the position of x _{1_1} is reacquired and corrected to be perpendicular to the reference line r, and an imaginary straight line connecting the corrected x _{1_1} and x _{2_1} is set to the width (w) of the final welding area. By dividing the width w of the obtained welding area, the welding trajectory c to which the welding torch 30 should be followed is obtained.

As a result, in the present invention, the joint distance of the steel pipe is not uniform and the end of the welding torch 30 can always be positioned at the center of the joint even when the steel pipe is not a round shape, and as a result, welding to the correct position can be made. have.

On the other hand, in the present invention, due to the high temperature heat generated by the welding torch 30, there is a fear that the sensing performance of the edge sensing in the sensing unit 40, there is a serious functional degradation of the sensing unit 40 of course internally There is a risk of causing phosphorus damage, the present invention may be installed an insulating plate (not shown) to block the flow of heat between the welding torch 30 and the sensing unit 40 to prevent this.

The insulation plate is made of a material having excellent heat shielding performance, and preferably the high heat generated from the welding torch 30 to the sensing unit 40 is difficult to access. For this purpose, the present invention is formed to be curved in an arc. It may be formed to surround the side of the sensing unit 40, the material of such a thermal insulation plate may be a ceramic having excellent heat insulating performance and excellent heat resistance.

The data processing unit 50, which derives the weld trajectory c by using the distance data acquired by the sensing unit 40, that is, the width w of the weld area, is a distance between the weld trajectory c and the welding torch 30. To calculate the traveling adjustment angle for the welding torch 30 to be positioned on the welding trajectory c by the result, and then the calculated driving adjustment angle described later as shown in FIG. 9. Provided by 60.

When the driving adjustment angle is provided by the data processing unit 50, the driving control unit 60 for adjusting the driving direction by controlling the driving unit 20 on the basis of the four driving wheels (a pair of left and right sides provided in the driving unit 20) is provided. The direction of travel is adjusted by adjusting the travel speed of 21, 22, 23, 24).

In the present invention, the pair of drive wheels (21, 22) located in front and rear of the four drive wheels to run at a constant speed, the running speed of the other front and rear drive wheels (23, 24) of the pair facing them It can be configured to be variable, by this configuration, the body 10 is driven along the joint of the steel pipe while rotating at an appropriate angle with the drive wheels (21, 22) as the rotation center, as a result of the welding torch (30) Since the welding follows the welding trajectory c accurately, the welding quality is improved.

In addition, the present invention may be implemented by installing encoders (not shown), respectively, on the driving wheels 21 and 23 positioned in front of each other, and the angles of rotation of the driving wheels 21 and 23 by these encoders. By measuring the change in the running angle of the main body 10 in real time, it is possible to more accurately control the rotation ratio and speed of the drive wheels (21, 23).

On the other hand, the welding torch 30 is fixed to the main body 10, the interval adjusting portion 70 for maintaining a constant distance between the welding torch 30 and the joint portion may be further provided, the gap adjusting portion at this time The sensor 70 detects the height of the steel pipe using a sensor provided separately from the sensing unit 40, and maintains the height of the welding torch 30 relatively to the predetermined height according to the detected height.

Examples of such a gap adjusting unit 70 is a horizontal rail 71 installed in the main body 10 and a movable block sliding along the horizontal rail 71 as shown in FIGS. 5 and 10 (a, b). (71), a vertical rail (73) installed on the movable block (71) and having a vertical length, and a movable block (74) installed on the vertical rail (73) to move up and down, and a movable block (74). Torch clamp 31 is provided at the free end of the) it can be implemented that the welding torch 30 is installed.

As a result, in the present invention, since the two moving blocks 72 and 74 move correspondingly along the horizontal rail 71 and the vertical rail 73, the height of the welding torch 30 as well as the left and right directions can be adjusted. Through the control of the driving unit 20, the main body 10 follows the joint of the steel pipe 1, and at the same time, the welding torch 30 is adjusted so that the joint is accurately positioned.

As a result, according to the present invention, as shown in FIGS. 11 and 12, the welding device 2 is kept in close contact with the surface of the steel pipe 1 and accurately follows the joint of the steel pipe 1 when traveling along the outer circumferential surface. While running, the spacing between the welding torch 30 and the joint is maintained in an optimal state.

As described above, according to the present invention, in the automatic welding device for a railless steel pipe, even when a bend is formed on the surface of the steel pipe, even when the distance between the steel pipe joints is not constant, the welding torch may always follow the joint accurately, and the welding may proceed. As a result, the reliability of the railless automatic welding device is improved.

1: steel pipe 2: welding device
10: main body 20: drive unit
30: welding torch 31: torch clamp
40: sensing unit 41: fixed bar
42: sensor 50: data processing unit
60: running control unit 70: gap adjusting unit
71: horizontal rail 72: moving block
73: vertical rail 74: moving block
c: welding trajectory w: width of welding area

Claims (5)

In the railless automatic welding device for automatically welding the joints of steel pipes,
A main body 10 having an enclosure shape;
A driving unit 20 installed on the bottom of the main body 10 and being in close contact with the surface of the steel pipe by magnetic force;
A welding torch 30 provided in the main body 10 and installed at an upper portion of the joint part;
It is provided in the drive unit 20, by detecting both edges of the steel pipe to obtain the position of x _{1_1} , x _{2_1} , respectively, A sensing unit 40 connecting a straight line to obtain a welding area w;
A data processor (50) for obtaining a weld trajectory (c) by dividing the width (w) of the welding region obtained through the sensing unit (40);
The railless automatic welding of the rail, characterized in that it comprises a traveling control unit 60 for adjusting the driving direction by controlling the drive unit 20 so that the center of the welding trajectory (c) and the sensing unit 40 coincide with each other. Device.
The method according to claim 1,
Four driving wheels 21, 22, 23, and 24 are installed in the driving unit 20, one pair of left and right sides respectively, and a pair of front and rear of the four driving wheels 21, 22, 23, and 24 is provided. The driving wheels 21 and 22 are configured to be driven at a constant speed, and the traveling speeds of the other front and rear driving wheels 23 and 24 facing them are configured to be variable,
The traveling control unit 60 adjusts the traveling direction of the front and rear drive wheels (23, 24) of the pair of railless steel pipe automatic welding device, characterized in that for adjusting the running direction of the main body (10).
The method according to claim 1 or 2,
The automatic welding device for a railless steel pipe, characterized in that the gap adjusting portion 70 for maintaining a constant distance between the welding torch 30 and the joint portion is further provided.
The method according to claim 1,
The sensing unit 40 further obtains x _{2_2} coordinates that follow the edge of one steel pipe,
To the virtual straight line connecting the x _{1_1} coordinates and the x _{2_1} coordinates the baseline (r), determine whether a virtual straight line connecting the x _{1_1} coordinates and the x _{2_1} coordinates forming the reference line (r) and the vertical ,
If the angle formed by an imaginary straight line connecting the reference line r, the x _{1_1} coordinates and the x _{2_1} coordinates is not a 90 ° angle, the x _{1_ 1} coordinates are reacquired, and when the angle is vertical, the x _{1_ 1} And a virtual straight line connecting a coordinate with the x _{2_ 1} coordinate as a width w of the welding region.
The method according to claim 3,
The gap adjusting unit 70 and the horizontal rail 71 is installed on the main body 10; A moving block (71) sliding along the horizontal rail (71); A vertical rail (73) installed on the movable block (71) and having a vertical length; The railless automatic welding device, characterized in that it comprises a moving block (74) installed on the vertical rail (73) to move up and down.

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