JP2002103086A - Automatic welding apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable high quality welding without depending on monitoring of an operator even in the case of welding a tube of various shapes and a narrow part. SOLUTION: An apparatus is provided with a welding head 1, which supports a torch turning base 5 self traveling along an outer periphery of a tube by a drive source to a support base 3 having a center hole copying an outer peripheral face of the tube and mounts a welding torch 4 on the turning base 5 to be freely moved, a clamp jig, which is arranged on the support base 3 and fixes the welding head by clamping the tube, a drive apparatus, which is arranged on the torch turning base 5 and drives the welding torch 4, a cable feed apparatus 12 to conduct feeding/returning of a welding cable to the welding torch 4 along a surrounding of the torch turning base 5 while linking with the self traveling of the torch turning base 5 and a controller 9 to control a drive source for controlling the torch turning base 5 and the drive apparatus to drive the welding torch 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic welding apparatus, and more particularly to an automatic TIG welding apparatus for performing groove welding or fillet welding of a pipe.

[0002]

2. Description of the Related Art Conventionally, in order to perform fillet welding when a flange or the like is welded to a pipe, a dedicated welding device is clamped on a straight pipe portion of the pipe, and a revolving stage that runs by itself along the outer surface of the pipe. , A welding torch is mounted, the welding torch is swiveled in parallel to the welding surface, and welding is performed while the welding target position and the welding voltage (arc length) are kept constant.

[0003]

However, applying the above-mentioned automatic welding apparatus to saddle-type welding of pipes has the following problems.

(1) When a welding torch is fixed to a torch swivel base, the height of the torch and the welded portion changes during welding, so that a displacement of the arc aiming position occurs, and the arc voltage also fluctuates. Can not do.

(2) When the pipe is bent near the welded portion or the axis of the tube clamped by the automatic welding device is inclined with respect to the welded portion, the torch swivel base to which the welding torch is attached is used. Since it is inclined with respect to the welding surface, a shift occurs at the arc target position during welding, and high-quality welding cannot be performed.

(3) When performing narrow welding with an interference in the vicinity of the welded portion, it is difficult to monitor by an operator, and therefore, a deviation of a welding target position during welding and a welding voltage (arc length).
Can not recognize the fluctuation of. Further, if the welding cable is caught by a surrounding interference object, the turning operation of the welding torch is hindered, so that welding cannot be performed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and automatically corrects a deviation of an arc aiming position and a fluctuation of an arc voltage, and performs welding without being affected by surrounding interference objects. Accordingly, it is an object of the present invention to provide an automatic welding apparatus capable of performing high-quality welding without monitoring by an operator even in welding of pipes of various shapes and narrow portions.

[0008]

According to the present invention, in order to achieve the above object, an automatic welding apparatus is constituted by the following means.

(1) A supporting base having a center hole following the outer peripheral surface of a pipe supports a torch revolving base self-propelled along the outer circumference of the pipe by a driving source, and a welding torch is movably mounted on the revolving base. A welding jig attached, a clamp jig provided on the support base, fixing the welding head by sandwiching the pipe, and a driving device provided on the torch swivel base to drive the welding torch; A cable feeder that interlocks with the self-propelled movement of the torch swivel base and feeds back the welding cable to the welding torch along the periphery of the torch swivel base; a drive source for the torch swivel base and a drive device for the welding torch And a control device for controlling the

(2) In the automatic welding apparatus according to the above (1), the driving device for driving the welding torch is a torch height direction for driving in a direction for changing a height between a welding portion of the pipe and the welding torch. A moving device, comprising a torch angle moving device that changes the angle of the welding torch facing the center of the pipe,
The torch height direction moving device and the torch angle moving device are controlled in accordance with welding conditions set by the control device.

(3) In the automatic welding apparatus according to the above (2), when the welding apparatus divides the welding length and individually sets the welding conditions, the control unit determines the difference between the height of the welding torch and the angle of the welding torch. The standard value is set.

(4) In the automatic welding apparatus according to the above (2) or (3), the control device controls a height between a weld portion of the pipe and a welding torch by a torch height direction moving device, Controls the arc length during welding.

(5) In the automatic welding apparatus according to the above (2), the control device controls the welding torch to perform a circular arc weaving operation in a lateral direction toward a welding line by a torch angle moving device.

(6) In the automatic welding apparatus according to the above (2), the control device controls the height between the welded portion of the tube and the torch by a torch height direction moving device, so that the arc length during welding is controlled. , And the welding torch is controlled by a torch angle moving device to perform a circular arc weaving operation in a lateral direction toward a welding line.

(7) In the automatic welding apparatus according to the above (6), the controller determines a welding target position deviation using a difference in torch height at both ends of the arc wiving as a parameter when performing arc length control. , Correct the center angle of the arc wiving.

(8) In the automatic welding apparatus according to the above (1), the clamp jig may have the same R as the outer dimension of the pipe.
The axial direction of the tube having a groove having a shape and being clamped is different from the axial direction of the turning of the welding torch.

Therefore, according to the automatic welding apparatus having the above structure, the torch swivel base is provided with a driving device for changing the torch height, and the driving device controls the welding voltage (arc length) to control the welding voltage (arc length). It is possible to perform welding with a constant welding voltage (arc length) even on a welded portion having a variable height such as a mold welded portion.

Further, by performing a circular arc weaving operation by a driving device for changing the torch angle, and correcting the center angle of the circular arc weaving based on a difference in the torch height at both ends of the circular arc weaving by the welding voltage (arc length) control. In addition, even if a welding target position shift occurs during welding due to a fixed position shift of the welding head, it can be corrected.

Furthermore, when the present invention is applied to a curved pipe, a clamp jig having a groove shape corresponding to the curvature of the pipe is provided so that the torch turning surface and the welding surface are parallel to each other, so that the welding target position can be adjusted. It can be kept constant regardless of the shape.

Further, by feeding back the welding cable in accordance with the turning operation of the welding torch, the welding cable does not slack during welding, and the welding cable does not catch on the surrounding interference objects. There is no welding interruption due to cable snagging.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a system configuration diagram showing an embodiment of an automatic welding apparatus according to the present invention.

In FIG. 1, reference numeral 1 denotes a welding head. The welding head 1 is a torch swiveling base 5 that swivels along a ring-shaped guide partially opened in a support base 3 attached to the tip of an arm 2. The welding torch 4 is provided on the torch swivel base 5 so as to be movable by a drive device described later. The torch swivel base 5 is driven by a drive source (not shown) and runs by itself along the outer circumference of the tube.

A welding wire 6 is provided at the rear end of the arm 2.
And a wire feeding device 7.

The welding equipment further includes a welding power source 8, a control device 9, a gas cylinder 10 filled with an inert gas for preventing oxidation during welding, and a water-cooled pump 11 for cooling the torch. It is connected to the supply device 7 via a lead wire, a gas supply pipe, and a water supply pipe.

The welding wire, the lead wire, the gas supply pipe and the water supply pipe collected in the wire feeding device 7 are combined into a welding cable 12, and the welding cable 12 is connected to the cable feeding device mounted on the support base 3. The device 13 enables the welding torch 4 to be fed back along the periphery of the torch turning base 5.

The control device 9 sets the welding length of one round of the pipe to 1
Various settings of welding conditions, proper torch aiming position, and arc copying function are made individually by dividing into two, and the welding head 1 can perform welding of the welded portion of the pipe according to the settings.

Next, the construction of the welding head 1 is shown in FIG.
(C).

2 (a) to 2 (c), a torch height direction moving device 14 and a torch angle moving device 15 are mounted on the torch turning base 5 as driving devices of the welding torch 4, respectively.

The torch height direction moving device 14 moves the welding torch 4 in the vertical direction integrally with the torch angle moving device 15.
Changes the supporting angle of the welding torch 4, and these operations are performed via the drive shaft 16.

Therefore, using these moving devices, welding is performed while moving the welding torch 4 along the outer periphery of the pipe by the torch swivel base 5, and the torch height direction moving device 14 is used.
, The welding voltage (arc length) is adjusted, and the torch angle moving device 15 makes it possible to adjust the target position of the welding torch and perform the circular arc weaving operation.

The cable feeding device 13 on the support base 3 operates in conjunction with the torch turning base 5 and automatically sends back the welding cable 12 in accordance with the rotation amount of the torch turning base 5. As a result, when the welding torch 4 turns around the outer circumference of the pipe during welding, the welding cable 12 can be maintained in a state of being wound around the torch turning base 5 without any excess or shortage as shown in FIG. Cable 12
The loosening of the welding torch interferes with the surrounding tube, which prevents the occurrence of a load that hinders the turning operation of the welding torch 4.

On the other hand, on the back side of the support base 3, a clamp jig 17 for fixing the welding head 1 with the tube in between is attached in order to maintain the positional relationship between the welded portion and the support base 3. The clamp jig 17 includes a welding head positioning block 18, a pair of fixing arms 19, and a welding head fixing block 20.

Here, the control device 9 controls the torch turning base 5.
And the torch height direction moving device 14 and the torch angle moving device 15 are controlled in accordance with various settings.

In the automatic welding apparatus having such a configuration,
A method for fixing the welding head 1 to the pipe will be described.

When the welding location is a straight pipe, first, the welding head fixing arm 19 of the clamp jig 17 is opened outward, and the pipe 30 is inserted between the fixing arms 19. Positioning is performed for 30 welds. Next, the welding head fixing arm 19 is closed inward, and is fixed by sandwiching the pipe 30 with the fixing block 20. Since the tube 30 is fixed at three points in this manner, it can be reliably fixed to the tube 30.

Further, the welding head positioning block 18 and the fixed block 20 of the clamp jig 17 are provided with a pipe 3
A groove having the same R dimension as the outer diameter of 0 is provided. By fixing the welding head 1 to the pipe 30 along this groove,
The contact area between the tube 30 and each of these blocks increases, and the displacement of the welding head 1 after the tube 30 is sandwiched can be prevented.

In the case where the welding application point is a curved pipe, as shown in FIG. 4, a clamp jig 17 having a welding head positioning block 18 having different groove angles and lengths according to the bent shape of the pipe 31 is used. At the same time, the mounting position and the angle of the fixing block 20 to the welding head fixing arm 19 are changed. Thereby, the angle of the torch swivel base 5 with respect to the welded portion can always be kept constant.

As a result, even if the bent shape of the pipe 31 to be welded is different, the positional relationship between the welded portion and the welding torch 4 can always be kept constant, and the fluctuation of the proper welding target position caused by the bent shape of the pipe 31 can be maintained. And welding with a constant quality can always be performed.

Next, the function of correcting the welding target position at the time of welding will be described.

FIG. 5 is a view for explaining the operation direction of the welding torch 4 on the torch swivel base 5.

The welding torch 4 is provided with a torch angle moving device 15.
Performs an arc operation as shown by the arrow in the figure. Further, the torch height direction moving device 14 integrally moves the welding torch 4 and the torch angle moving device 15 up and down.

When performing welding, the torch angle moving device 1 is used.
5, the welding torch 4 is wigged by an arcing operation, and the torch height direction moving device 14 is used so that the welding voltage (arc length) does not deviate from a set value by the AVC function when both ends are stopped and when moving between them. The position of the welding torch 4 is adjusted.

As shown in FIG. 6, when the flange 33 is connected to the pipe 32 by fillet welding, for example, the torch position 21 when the arc wiving is stopped inside and the torch position 22 when the arc wiving is stopped outside are torch angles. And the AVC function causes a difference 23 in the height of the torch depending on the shape of the base. The same applies to groove welding.

In this embodiment, the torch height difference 2
Taking the fluctuation of No. 3 as a parameter, the welding target position is corrected. That is, the torch position 2 at the time of stopping inside the arc wiving when welding is being performed at an appropriate target position.
1 and the difference 23 in the torch height between the torch position 22 when stopping outside.
When the target position is shifted inward from the appropriate position, the torch height of the torch position 21 when stopping inside is higher than usual, and the torch height of the torch position 22 when stopping outside is lower than normal. Become. Thereby, the difference 23 in the torch height becomes larger than usual.

On the other hand, when the target position is shifted outward from the proper position, the torch height at the torch position 21 when stopping inside is lower than usual, and the torch height at the torch position 22 when stopping outside is higher than usual. . Thus, the torch height difference 23 becomes smaller than usual.

In any of the above cases, the center of the circular arc wiving is the same whether the target position of the torch is shifted inward or outward.

Therefore, if the measured value of the torch height difference 23 is larger than the standard value in accordance with a command from the control device 9, the torch target position (center of the circular arc wiving) is shifted outward to measure the torch height difference 23. If the value is smaller than the standard value, a correction is performed to shift the torch target position (the center of the circular arc wiving) inward.

With the above correction, even when the fixed position of the welding head 1 is shifted from the standard state and the target welding position is shifted from the standard state, the target position is automatically corrected without monitoring and adjustment by the operator. be able to.

In such a welding position where the welding position changes, proper welding conditions can be set for each welding position, and high-quality welding can be performed.

[0051]

As described in detail above, according to the automatic welding apparatus according to the present invention, it is possible to set appropriate conditions for each welding position, and the welding cable interferes with the surroundings when turning the welding torch during welding. Therefore, it is possible to perform high-quality welding even at a narrow welding place where there is an obstacle in the surroundings without monitoring and adjusting by an operator.

Also, by employing a clamp jig according to the bent shape of the pipe to be welded, the positional relationship of the welding torch with respect to the welded portion can always be kept constant.
Work can be performed under the same welding conditions even for various bent shapes of pipes.

Further, since the welding target position can be automatically corrected by using the difference in the torch height when both ends of the arc wiving are stopped by the AVC function, the fixed position of the welding head is shifted from the standard state. Even in this case, it is possible to perform high-quality welding without monitoring and adjusting by an operator.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram showing an embodiment of an automatic welding device according to the present invention.

FIGS. 2A and 2B are diagrams showing a component configuration of a welding head according to the embodiment, wherein FIG. 2A is a front view, FIG. 2B is a bottom view seen from below (a), and FIG. FIG.

FIG. 3 is a view showing a state in which a welding cable is wound around a torch turning base during turning of the welding torch in the embodiment.

FIG. 4 is a diagram showing shapes and mounting positions of a welding head positioning block and a welding head fixing block when the welding head is fixed to a straight pipe and a curved pipe in the embodiment.

FIG. 5 is a view for explaining an operation of the welding torch on the torch turning base in the embodiment.

FIG. 6 is a diagram showing a position of a welding torch at the time when both ends are stopped in welding by arc wiving in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Welding head 2 ... Arm 3 ... Support base 4 ... Welding torch 5 ... Torch turning base 6 ... Welding wire 7 ... Year supply device 8 ... Welding power supply 9 ... Control device 10 ... Gas cylinder 11 ... Water cooling pump 12 ... Welding cable 13 ... Cable feeding device 14 ... Torch height direction moving device 15 ... Torch angle moving device 16 ... Drive shaft 17 ... Clamping jig 18 ... Welding head positioning block 19 ... Fixed arm 20 ... Welding head fixing block

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B23K 9/167 B23K 9/167 A // B23K 101: 06 101: 06

Claims (8)

[Claims] 1. A torch swivel base, which is self-propelled along the outer circumference of a pipe, is supported by a drive source on a support base having a center hole following the outer circumferential surface of the pipe, and a welding torch is movably mounted on the swivel base. A welding jig provided on the support base, the clamp jig sandwiching the pipe and fixing the welding head; a driving device provided on the torch swivel base to drive the welding torch; A cable feeder that interlocks with the self-propelled movement of the turning base and feeds back the welding cable to the welding torch along the periphery of the torch turning base; a driving source of the torch turning base and a driving device of the welding torch. An automatic welding device comprising a control device for controlling. 2. The automatic welding apparatus according to claim 1, wherein
A driving device for driving the welding torch changes a torch height direction moving device for driving in a direction for changing a height between a welding portion of the pipe and the welding torch, and changes an angle of the welding torch facing a center direction of the pipe. An automatic welding device comprising a torch angle moving device, wherein the torch height direction moving device and the torch angle moving device are controlled according to welding conditions set by the control device. 3. The automatic welding apparatus according to claim 2, wherein
An automatic welding apparatus, wherein the control device sets a welding torch height difference and a standard value of a welding torch angle when individually setting welding conditions by dividing a welding length. 4. The automatic welding apparatus according to claim 2, wherein the control device controls a height between a welded portion of the pipe and a welding torch by a torch height direction moving device to perform welding. An automatic welding apparatus characterized by controlling an arc length of a workpiece. 5. The automatic welding apparatus according to claim 2, wherein
The automatic welding device, wherein the control device controls the welding torch to perform a circular arc weaving operation in a lateral direction toward a welding line by a torch angle moving device. 6. The automatic welding apparatus according to claim 2, wherein
The control device controls a height between the welded portion of the pipe and the torch by a torch height direction moving device, controls an arc length during welding, and causes the torch angle moving device to move the welding torch to a welding line. An automatic welding apparatus characterized in that it is controlled to perform an arc weaving operation in a left-right direction. 7. The automatic welding apparatus according to claim 6, wherein
The automatic welding device, wherein the control device determines a welding target position deviation using a difference in torch height at both ends of the circular arc wiving as a parameter when performing arc length control, and corrects a center angle of the circular arc wiving. . 8. The automatic welding apparatus according to claim 1, wherein
The automatic welding apparatus according to claim 1, wherein the clamp jig has an R-shaped groove having the same outer shape as the pipe, and an axial direction of the pipe to be clamped is different from an axial direction of rotation of the welding torch.