JP2011079009A - Portable welding robot - Google Patents

Abstract

A single welding robot can handle various types of welding such as pipe inner and outer surface welding and seam welding.
Guide rails 10, 10 ′, 10 ″ disposed along a weld line, a traveling carriage 12 movable on the guide rail and detachable from the guide rail, A welding head 20 mounted on the traveling carriage 12, the welding head 20, a wire feeding device 40 for feeding a welding wire to the welding head 20, and a welding power source 50 for supplying power to the welding head 20. A portable welding robot comprising a plurality of mutually connected transport carts 80, in which at least a part of the control device 60 for controlling welding by the welding head 20 is distributed or collectively mounted, is used. .
[Selection] Figure 1

Description

  The present invention relates to a portable welding robot, and in particular, a single welding robot suitable for use in welding joints of on-site piping, and is capable of various welding such as pipe inner and outer surface welding and seam welding. Highly portable welding robot.

  Fluctuations such as gap gap and misplacement of field welded joints are relatively large. In particular, in the case of a large-diameter pipe welded joint, there is also a temporary bead. In order to automatically weld such a welded joint with a welding robot, it is necessary to provide the welding robot with a sensor for measuring a groove shape and an automatic control function based on the sensor information. It is also important to ensure welding quality by detecting these control errors in real time and performing correction control during welding.

  Most of the local pipes are fixed pipes. Therefore, in accordance with the change of the welding location, the welding robot used for welding must be moved instead of the pipe to be welded. In this case, there is a need for a portable welding robot that is lightweight and compact and that can be easily moved, assembled and set.

  As a prior art, an example of a technique related to automatic welding of a pipe is described in Patent Document 1, a technique related to inner surface welding of a pipe intermediate part is described in Patent Document 2, and a number of trucks equipped with welding equipment are connected. A technique related to the in-pipe traveling carriage is described in Patent Document 3, and a technique related to automatic welding control is described in Patent Document 4.

  In addition, the applicant has proposed a laser / visual composite sensor suitable for placement on a welding torch of a welding robot in Patent Documents 5 and 6.

Japanese Patent Laid-Open No. 9-295145 Japanese Patent Laid-Open No. 10-249585 Japanese Patent Laid-Open No. 11-268638 JP 2000-94130 A JP 2009-166107 A JP 2009-195977 A

  However, on-site piping welded joints include not only circumferential joints but also seam joints in the pipe axis direction. These joints are also desired to be able to be constructed entirely by a single welding robot, rather than multiple types of robots, due to the limited space in the pipe. Conventionally, welding robots with such versatility have been It was not proposed.

  The present invention has been made to solve the above-mentioned conventional problems, and it is an object of the present invention to provide a portable welding robot capable of various welding such as pipe inner and outer surface welding and seam welding with a single welding robot. To do.

  The present invention relates to a guide rail disposed along a welding line, a traveling carriage movable on the guide rail and detachable from the guide rail, and a welding head mounted on the traveling carriage. And at least of the welding head, a wire feeding device for feeding a welding wire to the welding head, a welding power source for supplying power to the welding head, and a control device for controlling welding by the welding head The above-described problems are solved by a portable welding robot that includes a plurality of transport carts that are partly distributed or collectively mounted and that can be connected to each other.

  Here, the traveling carriage may include a traveling wheel and a tightening wheel that sandwich the guide rail from both sides, and a wheel tightening lever for tightening the tightening wheel.

  The welding head includes a welding torch with a sensor, a mechanism for controlling the position of the traveling carriage with respect to the guide rail, a sensor for detecting the position of the traveling carriage with respect to the guide rail, and the height of the welding torch. And a mechanism for controlling the oscillation of the welding torch can be attached.

  Further, the sensor can be rotatable with respect to the central axis of the welding torch.

  In addition, a plurality of the traveling carriages can be disposed on one guide rail.

  According to the present invention, by arranging the guide rail along the welding line, various welding such as pipe inner and outer surface welding and seam welding can be performed by one welding robot.

The longitudinal cross-sectional view of the pipe for welding which shows the state before welding of the whole structure of embodiment of the portable welding robot which concerns on this invention (A) Cross sectional view and (B) Longitudinal sectional view showing the state during welding. The (A) front view and (B) side view which show the structure of the welding robot main body of the said embodiment. Similarly, an enlarged cross-sectional view of the main part showing a state where the traveling carriage is attached to the guide rail for welding the inner surface of the pipe. Similarly, an enlarged cross-sectional view of the main part when mounted on a guide rail for pipe seam welding Similarly, an enlarged cross-sectional view of the main part when mounted on a guide rail for pipe outer surface welding Similarly, an enlarged sectional view showing a mechanism for attaching and detaching the traveling carriage to the guide rail. Similarly, a front view showing the structure and operation of a welding torch holder Similarly, an exploded perspective view of a torch holder of a welding robot Front view showing the mounting state and operation of the combined laser / visual sensor (A) longitudinal sectional view and (B) transverse sectional view showing an application example of the embodiment to seam joint welding (A) Cross sectional view and (B) Longitudinal sectional view showing an example in which two welding heads are used simultaneously for one circumferential joint.

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

  FIG. 1 shows a state before welding of an embodiment of a portable welding robot according to the present invention, and FIG. 2 shows the entire structure in a state during welding. This welding robot is mainly arranged along, for example, a circumferential welding line of the pipe 8 to be welded. For example, a ring-shaped guide rail 10 is movable on the guide rail 10 as shown in FIG. A traveling carriage 12 that is detachably attached to the guide rail 10, a welding head 20 mounted on the traveling carriage 12, a wire feeding device 40 for feeding a welding wire to the welding head 20, A welding power source 50 for supplying power to the welding head 20, a control device 60 for controlling welding by the welding head 20, a cable / hose storage machine 70, and the like. Further, as auxiliary equipment, there are a transport cart 80 connected to each other, for example, a traveling motor 82 of the leading cart, a semi-automatic wire feeding device 42 disposed in the vicinity of the welding head 20, and the like.

  Considering installation in a narrow and narrow place in the pipe, or movement in a bent pipe, etc., storage of the wire feeding device 40, welding power source 50, control device 60 and cables, gas hoses, etc. as shown in FIG. The machine 70 is mounted on each transport cart 80. Moreover, if each conveyance cart 80 is connected, it can also move simultaneously. In addition, it is possible to attach the traveling motor 82 which is the electric motor of the motive power which drives the wheel to the head conveyance trolley, and to move it with motive power.

  Here, as shown in FIG. 1, the traveling carriage 12 of the welding head 20 is placed on the leading transport carriage 80 before welding and is transported to the vicinity of the guide rail 10, and then prepared for welding as shown in FIG. 2. Is mounted on the guide rail 10.

  3A (front view) and FIG. 3B (side view) show the welding robot body of the present embodiment. This robot body employs a combination type of a guide rail 10, a traveling carriage 12 that can be easily attached to and detached from the guide rail 10, and a welding head 20. As a result, if the same type of robot changes only the guide rail 10, it can be applied to circumferential welded joints with a wide range of pipe diameters, and can also be applied to welding of straight seam welded joints.

  A welding torch 22 with a combined laser / visual sensor 24 proposed by the applicant in Patent Documents 5 and 6 is attached to the welding head 20. As a result, automatic measurement of groove shape variation, tack bead position, etc. can be performed in advance before welding, and the welding state can also be measured during welding, so high-precision welding line scanning control and adaptive control of welding conditions High quality welding is guaranteed.

  The welding robot body includes a Z-axis mechanism of the traveling carriage 12 that moves the welding torch 22, a Y-axis mechanism 30Y that adjusts the height of the welding torch 22, and an X-axis mechanism 30X that controls the swinging of the welding torch 22. The welding torch 22 with the combined laser / visual sensor, the position sensor 32 for detecting the welding position from the position of the traveling carriage 12 on the guide rail 10, and the connector box 34 for gathering in / out of the cable / gas hose, etc. .

  The degree of freedom structure of the robot body is an orthogonal type of XYZ axes. Here, the welding torch 22 is directly attached to the slider of the X-axis mechanism 30X via the torch holder 36, and receives torch swing control from the X-axis.

  On the other hand, the X-axis mechanism 30X is fixed to the slider of the Y-axis mechanism 30Y and transmits the Y-axis torch height control to the welding torch 22. The XY axis block 30 configured as described above is fixed to the traveling carriage 12 by the Y-axis mechanism 30Y, and the traveling speed control of the traveling carriage 12 is used for the traveling speed control of the welding torch 22.

  FIG. 4 shows the structure of the traveling carriage 12. This traveling carriage 12 cooperates with a traveling wheel 12A traveling on one side (the upper side in the figure) of the guide rail 10, a traveling motor 12B for rotating the traveling wheel 12A, and the traveling wheel 12A. A tightening wheel 12C for sandwiching the rail 10 from the other side (lower side in the figure) and a wheel tightening lever 12D for tightening the tightening wheel 12C are provided. In the figure, reference numeral 12E denotes a mounting surface of the XY block 30.

  The traveling carriage 12 is attached to the guide rail 10 used for the inner surface welding of the pipe as shown in FIG. 4, and is also used for the straight guide rail 10 ′ used for the seam welding of the pipe shown in FIG. It is also characterized by being attached to a guide rail 10 "used for welding the outer surface of the pipe.

  Furthermore, the traveling carriage 12 can be easily attached to and detached from the guide rails 10, 10 ', and 10 ". FIG. 7 shows a mechanism for attaching and detaching the traveling carriage 12 to and from the guide rail 10. A tightening nut 12F and a tightening spring 12G for tightening the tightening lever 12D are provided, and the mechanism is characterized in that only one tightening nut 12F can be attached to and detached from the guide rail 10 of the traveling carriage 12. is there.

  FIG. 8 shows the structure of the torch holder 36, and FIG. 9 shows an exploded perspective view of the torch holder 36. The torch holder 36 includes a rotating portion 36A that can adjust the inclination of the torch in advance, an arm portion 36B that can adjust the vertical height of the welding torch 22 in advance according to the height of the guide rail 10, and a hand that catches the welding torch 22. It consists of part 36C. The rotating portion 36A is provided so that the welding torch 22 can aim at a groove at a predetermined angle when welding a fillet weld or an in-pipe seam joint. The arm portion 36B is provided in order to absorb the change in the guide rail height and to adjust the torch height during welding to suppress the stroke range of the Y-axis mechanism 30Y.

  FIG. 10 shows the welding torch 22 used in this embodiment. The welding torch 22 is provided with a sensor head 24A including a camera of the laser / visual combined sensor 24 proposed by the applicant in Patent Documents 5 and 6. The sensor head 24A is attached to the rotary block 24B and can be easily rotated 180 degrees around the central axis 22C of the welding torch 22. Therefore, the sensor head 24A for the visual sensor used during welding is installed. Even when the position is limited to the front in the welding direction, for example, welding can be performed in both directions.

  In the figure, 24C is a slider for adjusting the installation position of the sensor head 24A so that an image when the laser sensor is used is placed in the center of the camera visual field, and 24D is a fixing bolt thereof.

  FIG. 11A (longitudinal sectional view) and FIG. 11B (transverse sectional view) show an application example of the in-pipe welding robot to seam joint welding. In this case, the welding head 20 is placed on the linear guide rail 10 ′, and the wire feeding device 40 is placed on a frame 44 of the wire feeding device that can be interlocked with the welding head.

  FIGS. 12A (transverse sectional view) and (B) (longitudinal sectional view) are examples in which one circumferential joint is welded simultaneously using two welding heads (running carriages).

  Although the welding method shown in the drawing is a method of performing the sorting and upward welding, it goes without saying that the two machines can be run in the same direction and can be welded by rotating continuously around.

  In the above-described embodiment, the laser / visual composite sensor is used as the sensor. However, the type of sensor is not limited to this, and a sensor other than the laser sensor or a single sensor instead of the composite sensor may be used. Good. Further, the object to be welded is not limited to a pipe.

8 ... Pipe to be welded 10, 10 ', 10 "... Guide rail 12 ... Traveling carriage 12A ... Traveling wheel 12B ... Traveling motor 12C ... Fastening wheel 12D ... Fastening lever 12F ... Fastening nut 20 ... Welding head 22 ... Welding torch 24 ... Laser Visual composite sensor 24A ... sensor head 24B ... rotating block 30 ... XY axis block 30X ... X axis mechanism 30Y ... Y axis mechanism 36 ... torch holder 40 ... wire feeding device 42 ... semi-automatic wire feeding device 50 ... welding power supply 60 ... Control device 70 ... Cable / hose storage machine 80 ... Transport cart 82 ... Transport cart travel motor

Claims (5)

A guide rail disposed along the weld line;
A traveling carriage movable on the guide rail and detachable from the guide rail;
A welding head mounted on the traveling carriage;
At least a part of the welding head, a wire feeding device for feeding a welding wire to the welding head, a welding power source for supplying power to the welding head, and a control device for controlling welding by the welding head A portable welding robot comprising a plurality of transport carts that are connected to each other and that are mounted together.   The portable welding robot according to claim 1, wherein the traveling carriage includes a traveling wheel and a tightening wheel that sandwich the guide rail from both sides, and a wheel tightening lever for tightening the tightening wheel.   A welding torch with a sensor on the welding head, a mechanism for controlling the position of the traveling carriage with respect to the guide rail, a sensor for detecting the position of the traveling carriage with respect to the guide rail, and the height of the welding torch are controlled. The portable welding robot according to claim 1 or 2, wherein a mechanism for controlling and a mechanism for controlling swinging of the welding torch are attached.   The portable welding robot according to claim 1, wherein the sensor is rotatable with respect to a central axis of the welding torch.   The portable welding robot according to any one of claims 1 to 4, wherein a plurality of the traveling carriages are disposed on one guide rail.

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