WO2013056414A1

WO2013056414A1 - Automatic welding method for circumferential welding seam of round pipe

Info

Publication number: WO2013056414A1
Application number: PCT/CN2011/080906
Authority: WO
Inventors: 詹纯新; 刘权; 王莲芳; 易伟平
Original assignee: 中联重科股份有限公司; 湖南中联重科专用车有限责任公司
Priority date: 2011-10-18
Filing date: 2011-10-18
Publication date: 2013-04-25

Abstract

Disclosed in the present invention is an automatic welding method for a circumferential welding seam of a round pipe. During the welding process, the round pipe (5) rotates relative to a welding gun (1), and the welding position and welding angle of the welding gun in a three-dimensional direction can be automatically adjusted so as to realize automatic welding of the circumferential welding seam. By the method, the welding position and the welding angle can be flexibly and accurately adjusted so as to automatically perform multi-layer and multi-pass welding to form a circumferential welding seam with relatively good mechanical performance.

Description

Automatic welding method for circumferential weld of round pipe

Technical field

The invention belongs to the field of pipe welding technology, and in particular relates to an automatic welding method for a circumferential weld of a round pipe. Background technique

Truss structures are common in large-scale buildings, exhibition halls, stadiums, and bridges. Among them, some of the truss arms are formed by welding a round tubular chord at both ends with an ear hinge or a support, and the weld formed by the truss arm after the completion of the welding is a circumferential weld. Due to the force characteristics of the truss structure, the circumferential weld formed on the truss arm is required to have high mechanical properties such as joint strength. Therefore, the circumferential weld is required to be sufficiently strong and has a certain section size, and considering the circle to be welded. The wall thickness and roundness of the pipe, the circumferential weld formed should also have a greater width and thickness. Therefore, in the welding, the multi-layer welding is required in the wall thickness direction of the welded round pipe member, and multiple welding is required on some layers in the axial direction of the circular pipe member, thereby forming a multi-layer multi-pass circumferential weld. .

If manual all-position welding is used to form a multi-layer multi-pass circumferential weld, the welding tool is required to have all-position welding skills, the welder has a very high requirement, the welding time is long, and the labor intensity is high. Among the automatic welders that can be used for circumferential weld welding, some use the welding method in which the circular pipe workpiece is not moved and the welding head rotates around the circular pipe workpiece. This requires a support rail for the rotation of the welding head and a welding head rotation. The space is therefore often erected to facilitate the welding. The above welding method is difficult to operate for round pipe members (such as chords) having a large length and diameter and a large weight. Moreover, in the conventional automatic welding machine, the degree of automation of various adjustment mechanisms for adjusting the welding position is insufficient, and many are manual adjustments, which is obviously difficult to meet the welding requirements of the above-mentioned multi-layer multi-pass circumferential weld. In addition, especially when welding several circumferential welds on the same circular pipe, the synchronization problem of each weld is involved. Summary of the invention

SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic welding method for a circumferential weld of a round pipe member in accordance with the above-mentioned deficiencies of the prior art, to automatically and automatically complete the welding of the circumferential weld.

According to an aspect of the invention, an automatic welding method for a circumferential weld of a round pipe member is disclosed, wherein the round pipe member rotates relative to the welding gun, and the welding position and welding angle of the welding torch in a three-dimensional direction It can be adjusted automatically to achieve automatic welding of circumferential welds.

Preferably, the circumferential weld of the circumferential weld is achieved by automatically adjusting the axial position of the welding gun relative to the tubular member during the welding process.

Preferably, the lane dividing welding process comprises:

1) adjusting the initial welding position and welding angle of the welding torch relative to the round pipe member;

2) The welding torch starts to arc;

3) driving the round pipe to rotate to complete the welding of the first weld;

4) The welding gun automatically moves axially to the welding position of the next weld, adjusts the welding angle, and completes the welding of the next weld;

5) Repeat step 4) until each weld of the circumferential weld is completed.

Preferably, the layered welding of the circumferential weld is achieved by automatically adjusting the radial position of the welding gun relative to the tubular member during the welding process.

Preferably, the layered welding process comprises:

a) adjusting the initial welding position and welding angle of the welding torch relative to the round pipe member; b) the welding torch arcing and driving the round pipe member to rotate;

c) welding one or more welds by the split welding on the first layer of welds to complete the welding of the welds;

d) after the welding of the first layer of weld is completed, the welding gun automatically lifts the gun, moves radially to the welding position of the first weld of the next layer of weld, adjusts the welding angle, and welds through the lane Finishing welding of the next layer of welds; Preferably, during the welding process, the torch tracking mechanism is used to avoid radial runout of the tubular member.

Preferably, during the welding process, when the welding torch is performing the welding of the circumferential weld, the welding torch follows the position of the welding gun tracking mechanism.

Preferably, during the welding process, the temperature of the detection point on the outer peripheral surface of the round pipe member is detected in real time, and the axial distance between the detection point and the midpoint of the circumferential weld bead is 75-100 mm.

Preferably, the welding and the welding of the welding torch are controlled according to the temperature of the above-mentioned detection point, so that the temperature of the detection point is maintained in the range of 100 ° - 200 °.

Preferably, the welded portion of the round pipe member is preheated prior to welding.

After the automatic welding method of the circumferential weld of the round pipe member of the present invention, the round pipe member rotates relative to the welding gun during the welding process, and the welding position and the welding angle of the welding torch in the three-dimensional direction can be automatically adjusted, thereby enabling The welding position and welding angle are more flexibly and precisely adjusted to automatically perform multi-layer multi-pass welding to form a circumferential weld with better mechanical properties.

Other features and advantages of the invention will be described in detail in the detailed description which follows. DRAWINGS

The drawings are intended to provide a further understanding of the invention, and are in the In the drawing:

1 is a schematic structural view of an automatic welder according to an embodiment of the present invention. detailed description

In the present invention, the orientation words used, such as "axial", "radial", etc., are generally for a circular pipe member, and in the coordinates representing the three-dimensional direction in Fig. 1, "there is no description to the contrary," The X" axis indicates the axial direction of the round pipe, and the "Y" and "Z" axes indicate the radial direction of the round pipe. The term "welding" The position of the welding gun is the position at which the welding gun tip is welded. The "welding angle" is the inclination angle of the welding gun from the vertical direction (or horizontal direction) at the center of the welding point, that is, the welding gun swing during the swing welding. The angle of inclination between the centerline and the vertical (or horizontal).

Referring to Figure 1, according to the present invention, an automatic welding method for a circumferential weld of a circular pipe member is disclosed. During the welding process, the round pipe member 5 is rotated relative to the welding torch 1, and the welding torch 1 is welded in a three-dimensional direction. The position and welding angle can be adjusted automatically to achieve automatic welding of the circumferential weld. In the method of the present invention, as shown in FIG. 1, the round pipe member 5 is welded in such a manner that the welding torch 1 is relatively stationary, and the welding method of the present invention is more convenient and practical with respect to the welding manner in which the welding torch 1 rotates around the workpiece. The round pipe member 5 does not have to be erected to facilitate the rotation of the welding gun 1, nor does it require a support rail for the rotation of the welding head 2 and a space for the welding head 2 to rotate, and the welding efficiency is also improved. More importantly, because the welding torch 1 is relatively stationary, it is easier to optimize the welding process of the circumferential weld by controlling the welding position and welding angle of the welding torch 1. In particular, when welding a multi-layered circumferential weld, the round pipe member 5 can be self-rotating, and the welding position and the welding angle of the welding torch 1 can be automatically adjusted, that is, the height of the welding gun and the welding width can be adjusted. The welding of the layered lanes eventually forms a multi-layered circumferential weld, which will be described in detail below.

In the automatic welding machine shown in Fig. 1, a welding position adjusting mechanism and a welding angle adjusting mechanism are provided in the welding head 2 of the automatic welding machine. The welding position adjusting mechanism can adjust the welding position by a slide rail device respectively disposed in a three-dimensional direction, and the welding angle adjusting mechanism can adjust the welding angle of the welding torch by rotating the rotating shaft for fixing the welding gun 1. And connecting the welding position adjustment mechanism. The structure of the welding position adjusting mechanism and the welding angle adjusting mechanism will not be described in detail herein, and those skilled in the art can realize the above-mentioned welding position adjusting mechanism and welding angle adjusting mechanism by various structures or manners. In order to realize the automatic adjustment of the welding position and the welding angle of the welding torch 1 in the three-dimensional direction, the automatic welding machine is equipped with a welding control system (not shown) having a control program, such as a PLC control system, capable of respectively Automatically controlling the welding position adjusting mechanism and the welding angle adjusting mechanism in the welding head 2, so that the welding position and the welding angle of the welding torch 1 in the three-dimensional direction can be automatically adjusted, and the circular pipe member 5 is rotated. The welding of the circumferential weld is completed on the basis of the rotation. In the automatic welding machine shown in Fig. 1, the welding position adjusting mechanism and the welding angle adjusting mechanism can be integrated in the welding head 2, so that the structure is more compact, and motion interference is not easily generated, and each welding position adjusting mechanism is The coordination and linkage between the two can also make the welding head 2 more convenient to connect and cooperate with other mechanisms such as the welding gun tracking mechanism 3 which will be described below. In addition, the welding position adjusting mechanism and the welding angle adjusting mechanism are integrated in the welding head 2, and it is more convenient to adjust the position of the welding torch in a certain direction indirectly by adjusting the position of the welding head 2. Automatic control, and the control program of the direct control mode is simple and the precision can be higher.

When the circumferential weld of the round pipe member 5 has a large cross-sectional dimension, a wide width, or a high mechanical property requirement of the welded round pipe member 5, it is difficult to form a required circumferential weld bead or a formed one-time welding. The mechanical properties of the circumferential welds are not up to standard, and multiple layers of welding are required. Therefore, in the case of the split welding, the circumferential position of the circumferential weld can be realized by automatically adjusting the axial position of the welding torch 1 with respect to the round pipe member 5 (the X-axis direction in Fig. 1) during the welding process. welding. That is, while the round pipe member 5 is rotated, the round pipe member 5 is completely rotated by the welding control system. After the welding of one weld bead is completed, the welding control system automatically controls the welding torch 1 to move in the axial direction of the round pipe member 5 to At the next weld, the next weld is welded.

Specifically, the lane welding process may include the following steps:

1) adjusting the initial welding position and welding angle of the welding torch 1 with respect to the round pipe member 5; in this step, as shown in Fig. 1, the round pipe member 5 is mounted on the workpiece rotary drive mechanism 6 and positioned, and the motor 9 is driven. a column slider 8 on the column 7 to drive the welding head 2, so that the adjusting head 2 approaches the round pipe member 5, and then controls the welding head 2 through the welding control system to make the welding gun 1 reach the initial welding position and the welding angle;

2) The welding torch is arced; after the welding gun 1 reaches the initial welding position and the welding angle, the welding can be prepared;

3) driving the round pipe member 5 to rotate to complete the welding of the first weld seam; 4) the welding torch 1 is automatically moved axially to the welding position of the next weld, the welding angle is adjusted, and the welding of the next weld is completed; wherein, in the welding control system, the first weld is judged to be completed. After welding, the welding gun can be automatically controlled to automatically axially

(ie, the X-axis direction in Figure 1) moves to the welding position of the next weld and completes the welding of the next weld;

5) Repeat step 4) until each weld of the circumferential weld is completed.

The above-mentioned lane welding process can automatically realize the lane welding by controlling the automatic movement of the welding torch in the axial direction of the round pipe member 5 (the X-axis direction in Fig. 1).

In the case of the layered welding, the layered welding of the circumferential weld is achieved by adjusting the radial position of the welding torch 1 relative to the round pipe member 5 during the welding process. The radial position of the round pipe member 5 is the Y or z-axis direction in Fig. 1. Since the welding gun 1 is generally directly above the axis of the round pipe member, generally the direction of the gun is raised in the Z-axis direction, but the welding torch can also be Radial displacement is performed in the Y or Z axis or any other radial direction to complete the layered welding.

Wherein, the layered welding process may include:

a) adjusting the initial welding position and welding angle of the welding torch 1 relative to the round pipe member 5; b) the welding torch 1 arcing and driving the round pipe member 5 to rotate;

c) welding one or more welds on the first layer of weld by the split welding to complete the welding of the weld; wherein, since the weld is formed at the weld of the round pipe 5 before welding, As the first weld of the bottom layer of the required weld, it is generally only necessary to weld one weld, and the more the weld layer, the wider the weld, the more welds are required.

d) after the welding of the first layer of weld is completed, the welding gun 1 automatically lifts the gun, moves radially to the welding position of the first weld of the next layer of weld, adjusts the welding angle, and passes the lane Welding to complete the welding of the next layer of welds;

e) Repeat step d) until each weld of the circumferential weld is completed.

In the above automatic welding process, the welding torch is automatically controlled by the welding control system. The position moves to complete the weld. The automatic welding process can also be suspended, and the welding angle or position of the welding torch can be adjusted by operating the welding control system to achieve manual intervention in the automatic welding process.

In the present embodiment, as an example of a combined welding for forming a truss arm, the round pipe member 5 is a chord having a large size and a large occupied space, and the struts are joined to the ear hinge or the support by welding to form a truss arm. . As mentioned earlier, multiple layers of welding are required in the wall thickness direction of the chord. Therefore, preferably, in the welding process of the chord as the round pipe member, layered welding is employed in the wall thickness direction of the circular pipe wall of the round pipe member 5, and the round pipe member 5 of each layer is Split tunnel welding is used in the axial direction. Correspondingly, the welding position of the welding torch in the wall thickness direction of the round pipe wall of the round pipe member is adjusted by the welding head to realize the layered welding; the welding torch is adjusted by the welding head The welding position of the round pipe member in the axial direction to achieve the split welding.

During the welding, due to the imbalance of the circumferential surface of the round pipe member 5, the round pipe member 5 that rotates during welding inevitably has a runout, thereby affecting the welding quality. Therefore, in the automatic welding process, the torch tracking mechanism 3 can be used to avoid the radial runout of the round pipe member 5. The rolling pin 4 of the welding torch tracking mechanism 3 fixedly coupled to the welding head 2 is pressed against the surface of the circular pipe member 5 by the tensioning force applied by the tensioning mechanism to prevent the round pipe member 5 from jumping and to ensure accurate welding position. And, during the welding process, when the welding torch 1 is performing the welding of the circumferential weld, the welding gun 1 can follow the position of the welding gun tracking mechanism 3. That is to say, when the surface of the round pipe member 5 is uneven, since the rolling pin 4 is fixedly connected with the welding head 2, the welding gun 1 can follow the rolling pin 4 to make corresponding position adjustment, so that the welding is accurately positioned, and the welding quality is better.

In addition, in the welding process, in order to ensure the quality of the welded seam to be welded and meet the mechanical performance requirements, it is necessary to detect the temperature of the detection point on the outer peripheral surface of the round pipe member in real time. Preferably, the axial distance between the detection point and the midpoint of the circumferential weld is 75-100 mm. Moreover, the welding and stopping welding of the welding torch can be controlled according to the temperature of the above-mentioned detection point, so that the temperature of the detecting point is maintained in the range of 100° - 200°, and a circumferential weld seam with better mechanical properties can be obtained. In particular, the welding portion of the round pipe member should be preheated before welding, so that the welding portion The temperature is preferably at the time of soldering.

In addition, when welding of several circumferential welds is required on the same round pipe member 5, it is generally required to perform welding in sequence, so that it is not only necessary to move and reinstall the positioning round pipe member 5 or the automatic welding machine, and it is more difficult to ensure the circumferential welding. The quality of the seams. By using the automatic welding method proposed in the present invention, a plurality of welding places for circumferential weld welding can be provided on the round pipe member 5, and an automatic welding machine is disposed for each of the welded portions, and the automatic welding machine adopts the above-mentioned The automatic welding method of the circumferential weld seam enables the automatic welder to synchronously perform the automatic welding of the circumferential weld seam by setting the welding control system of the automatic welder, thereby achieving simultaneous welding of the round pipe member 5. When the automatic welding machine is synchronized for automatic welding, each welding welding control system can be set to be synchronized, that is, the same initial welding position and initial welding angle are set, and the respective welding head 2 is simultaneously driven for automatic In the welding process, the welding of several circumferential welds of the round pipe 5 is finally completed synchronously. Thus, the plurality of circumferential welds after welding can have substantially the same mechanical properties and the like. Of course, in the case where the welding control system of each automatic welding machine is the same control system and can be integrated, for example, when the welding control system is a PLC control system, the PLC control system can be developed to make a plurality of the PLC control systems. Integrated into a total welding control system, multiple automatic welding machines can be controlled simultaneously by a total welding control system to achieve simultaneous welding of several circumferential welds.

According to the automatic welding method of the present invention, when the welding position and the welding angle of the welding gun 1 are automatically adjusted, since the welding gun 1 does not rotate, the automatic control of the welding gun 1 is relatively easy and the control procedure is simpler. In the present embodiment, the welding position control mechanism and the welding angle adjusting mechanism in the welding head 2 are automatically controlled by the welding control system (not shown) of the automatic welding machine, thereby automatically adjusting the welding position of the welding torch 1 in the three-dimensional direction. And the welding angle, so that the automatic welding of the welding torch 1 can be realized in the automatic welding process, thereby automatically completing the welding of the circumferential weld. This automatic welding method is especially suitable for multi-layer multi-channel circumferential weld welding, which not only increases the welding efficiency, but also improves the welding precision.

The automatic welding method of the circumferential weld of the present invention has been carried out by the specific embodiment above. The detailed description is merely illustrative, and not restrictive, and various modifications or alternatives are readily apparent to those skilled in the art.

It is to be noted that the preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the specific details of the embodiments described above, and the technical solutions of the present invention may be made within the scope of the technical idea of the present invention. A variety of simple variations or substitutions are within the scope of the invention.

Claims

Rights request

1. An automatic welding method for a circumferential weld of a circular pipe member, characterized in that, during welding, the round pipe member (5) is rotated relative to the welding gun (1), and the welding torch (1) is in a three-dimensional direction The welding position and welding angle can be automatically adjusted to achieve automatic welding of the circumferential weld.

2. The method of automatically welding a circumferential weld of a round pipe member according to claim 1, wherein, during the welding, by automatically adjusting the axial position of the welding gun (1) relative to the round pipe member (5), Achieve cross-track welding of circumferential welds.

3. The method of automatically welding a circumferential weld of a round pipe member according to claim 2, wherein the branch welding process comprises:

1) adjusting the initial welding position and welding angle of the welding torch (1) relative to the round pipe member (5);

2) Welding torch (1) arcing;

3) driving the round pipe member (5) to rotate to complete the welding of the first weld seam;

5) Repeat step 4) until each weld of the circumferential weld is completed.

4. The method of automatically welding a circumferential weld of a round pipe member according to claim 3, wherein, during the welding, by automatically adjusting a radial position of the welding torch (1) relative to the round pipe member (5), A layered weld of the circumferential weld is achieved.

5. The method of automatically welding a circumferential weld of a round pipe member according to claim 4, wherein the layered welding process comprises: a) adjusting the initial welding position and welding angle of the welding torch (1) relative to the round pipe member (5);

b) the welding torch (1) starts to arc and drives the round pipe member (6) to rotate;

d) after the welding of the first layer of welds is completed, the welding gun (1) automatically lifts the gun, moves radially to the welding position of the first weld of the next layer of welds, adjusts the welding angle, and passes the Cross-track welding to complete the welding of the next layer of welds;

e) Repeat step d) until each weld of the circumferential weld is completed.

6. The method of automatically welding a circumferential weld of a round pipe member according to claim 1, wherein the welding torch tracking mechanism (3) is used to prevent radial runout of the round pipe member (5) during the welding process.

7. The method of automatically welding a circumferential weld of a round pipe member according to claim 6, wherein, in the welding process, when the welding torch (1) is welding the circumferential weld, the welding torch

(1) Follow the position of the welding gun tracking mechanism (3).

8. The method of automatically welding a circumferential weld of a round pipe according to claim 1, wherein in the welding process, the temperature of the detection point on the outer circumferential surface of the round pipe member is detected in real time, and the detection point is welded to the circumference. The axial distance between the midpoints of the slit is 75-100 mm.

9. The method of automatically welding a circumferential weld of a round pipe according to claim 1, wherein the welding and stopping of the welding torch are controlled according to the temperature of the detecting point, so that the temperature of the detecting point is maintained at 100. -200° range.

The automatic welding method of the circumferential weld of the round pipe member according to claim 1, wherein the welded portion of the round pipe member (5) is preheated before welding.