CN114619172A - Automatic welding special machine for circumferential multilayer multi-pass welding seam - Google Patents

Abstract

The special automatic welding machine for multilayer and multi-pass welding seams on the circumference is a welding corollary device for completing mechanical and automatic welding by changing the angle and the position of a weldment; the workpiece is subjected to pre-treatment of assembling spot welding in advance, and then the workpiece is fixed on a positioner in a manual mode. After the operator presses the start button, the workstation operates according to a preset program. The method comprises the steps of scanning point laser and determining the position angle of a workpiece, clamping a welding gun by a robot to reach the position of a welding seam, determining the starting point of the welding seam under the coordination of a contact sensing function, calculating the track deviation by the robot and then starting welding, adopting swing welding in the welding process, enabling an arc tracking system to track the change of an arc and automatically correct the track, eliminating the influence caused by the error of the workpiece and the welding deformation in the welding process, ensuring the optimal welding quality, reducing the labor intensity of a welder and improving the production efficiency.

Description

Automatic welding machine for circular multi-layer multi-pass welding

technical field

The invention belongs to the field of mechanical manufacturing, and particularly relates to a special automatic welding machine for circumferential multi-layer multi-pass welding seams.

Background technique

The existing circumferential multi-layer multi-pass welding products have the following problems in the component welding process

a. It is necessary to turn over several times to adjust the welding position, the welding operation is difficult, and the technical requirements for workers are high;

b. The welding quality is controlled manually, and defects such as pores, incomplete penetration and cracks often appear in the welding seam, and the welding quality is often difficult to guarantee;

c. The appearance of the welding seam is uneven, and the height of the welding angle cannot be controlled, so it is difficult to meet the strict requirements of the project product on the total weight, resulting in a great increase in the grinding workload;

d. For single-sided welding, the welding deformation is large, which cannot meet the technical requirements stipulated by the ISO 13920/BF standard. After welding, pyrotechnic correction is required, and the process is complicated.

Difficulties of circumferential multi-layer multi-pass welding products are difficult welding operation, low welding efficiency, and welding quality is completely controlled by humans, which can no longer meet the needs of the technical requirements specified by the project products.

SUMMARY OF THE INVENTION

The purpose of the present invention is to change the problem of difficult quality control caused by manual welding, and can also greatly improve the production efficiency.

The automatic welding machine for circular multi-layer multi-pass welds has certain advantages for the welding of annular welds of structural parts, and has the advantages of high welding efficiency, small deformation of workpieces after welding, high stability of product quality and improved working conditions for workers , and the device has the advantages of simple and convenient operation.

In order to achieve the above purpose, an automatic welding machine with multi-layer and multi-pass welding seams is provided, which is mainly composed of gantry traveling mechanism, welding robot system, welding positioner and other main parts;

The gantry-type walking mechanism is driven by an external axis servo motor to rotate, can be freely programmed, and can be combined with the welding robot system for trajectory interpolation; it can coordinate and communicate with the welding robot, and the walking speed and acceleration can be adjusted to ensure that the mechanism is stable when walking. Shake; ensure the walking accuracy and effective stroke to meet the welding needs of the workpiece;

Each axis of the robot in the welding robot system is equipped with an intelligent anti-collision sensing device, which can not only play a protective role when hitting the gun, but also can activate this function when any object abnormally touches the robot or the welding gun cable wraps around the robot. It greatly ensures the personal safety of the operator, and can play an excellent protective effect on the welding torch; the welding positioner has an arc tracking function, and the system samples the current and voltage signals in the swing welding in real time. Irregularity and deformation generated in the welding process are analyzed to obtain data to modify the robot path, which can adapt to the deformation of the workpiece during the welding process.

The flipping of the welding positioner is driven by an external shaft motor and can be freely programmed; it is combined with the robot system to perform trajectory interpolation; There will be no self-flipping after locking, abnormal noise and vibration, etc., and the safety factor is greater than 1.5 times; the surface of the workpiece clamped by the positioner is in a horizontal state, and its plane height is low, which is convenient for workpiece clamping, disassembly and welding process. observation.

The automatic welding method of circular multi-layer multi-pass welding seam, according to the welding requirements, using database resources, can automatically set each welding condition, generate multi-layer welding program during automatic robot welding, and automatically execute multi-layer welding. The welding robot system has the function of adjusting the angle between layers and the function of automatic welding torch positioning; during the multi-layer multi-pass welding process, the first or other welds are interrupted unexpectedly (such as collision) during the welding process, and there is no need to re-edit or modify the program. , with the function of continuing to complete the remaining welds.

The absolute position encoder of the robot system can store the position (x/y/z) and angle (A/B/C) of the welding torch in space in real time.

When the robot touches the charged welding wire to the workpiece according to the set program, a loop is formed between the welding wire and the workpiece, and the control system compares the current actual position with the position parameters during teaching.

For the new welding track, the current data is combined with the teaching track, and the data is corrected to correct the welding track.

The position and shape deviation of the workpiece makes the originally taught robot welding trajectory to be "corrected". The Seam ArcTracking function package can correct such deviations during the welding process, and the actual welding trajectory of the robot will be corrected to track the actual welding seam; if Use in conjunction with the Touch Sensor feature pack for best results.

When welding thick plates or fillet welds, the welding torch swings, and the rod elongation of the welding wire in the middle of the weld is different from that on both sides of the weld, and the rod elongation is different, resulting in the actual welding current and the set current. Differently, the shorter the rod elongation, the higher the actual current, and the longer the rod elongation, the lower the actual current.

Using this principle, the corresponding software processes the detected current changes and the position of the welding torch in real time, and then corrects the actual trajectory of the robot to ensure that the center line of the trajectory is always in the middle of the groove, or at the 45° position of the fillet weld. On the line; at the same time, ensure the consistency of the welding torch in the height direction.

When this function is activated, the feedback and processing frequency of relevant data can reach once every 12 microseconds, and the tracking accuracy is 0.1mm.

After the operator presses the start button, the workstation runs according to a pre-set program.

The spot laser scans and determines the position angle of the workpiece. The robot clamps the welding torch to the position of the welding seam. With the cooperation of the contact sensing function, the starting point of the welding seam is determined. The robot calculates the trajectory offset and starts welding. The welding process adopts swing welding, arc welding The tracking system will track the arc change and automatically correct the trajectory, eliminate the influence of the workpiece itself error and the welding deformation caused by the welding process, and ensure the best welding quality.

Including a set of gantry traveling mechanism, a set of welding positioner, and a set of welding robot system.

The preferred solution of the present invention is: a set of gantry traveling mechanism, a set of welding positioner, and a set of welding robot system are designed to be fast loaded and unloaded under the premise of ensuring strength, and the shielding of welding positions is reduced.

Preferably, the gantry traveling mechanism can be freely programmed, and can be combined with the robot system to perform trajectory interpolation, so as to ensure the traveling accuracy of the mechanism.

Preferably, the welding robot system has the functions of arc tracking, positioning accuracy, anti-interference, collision, etc. The whole system can realize off-line programming to improve production efficiency. Considering that once the welding quality problem of the welded workpiece can be effectively traced, the system also needs to have The arc monitoring function can record the fluctuation of all welding process parameters (current, voltage, welding speed and other parameters) during the welding process from the starting point of welding to the end of welding.

Preferably, the design of the welding fixture of the welding positioner strives for modularization and standardization, and an integrated base is used to ensure the stability of the relative position of each unit. Clamping time≤10min. The welding fixture should have the function of self-locking and error-proofing; the welding fixture has good rigidity, sufficient clamping force, and automatic clamping. Different size workpieces can share a set of tooling, and workpieces with large changes only need to adjust the tooling components to realize the workpiece. Quick changeover. The positioning and clamping part of the fixture takes into account the heat dissipation of the workpiece during welding and the stability and reliability of the clamping to ensure good welding quality.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings.

FIG. 1 is a schematic diagram of the overall design of the present invention.

FIG. 2 is a schematic diagram of the welding positioner of the present invention.

Figure 3 is a schematic diagram of the assembly of the welding positioner.

FIG. 4 is a schematic diagram of the welding robot body.

Figure 5 is a schematic diagram of electrical control.

Figure 6 is a schematic diagram of multi-layer multi-pass welding.

Detailed ways

Example 1

Referring to FIG. 1 , this embodiment provides a special automatic welding machine for circumferential multi-layer multi-pass welding, including a set of gantry traveling mechanism, a set of welding positioner, and a set of welding robot system.

Multi-layer multi-pass welding method: absolute position encoder of the robot system, real-time memory of the position (x/y/z) and angle (A/B/C) of the welding torch in space.

When the robot touches the charged welding wire to the workpiece according to the set program, a loop is formed between the welding wire and the workpiece, and the control system compares the current actual position with the position parameters during teaching.

For the new welding track, the current data is combined with the teaching track, and the data is corrected to correct the welding track.

The position and shape deviation of the workpiece makes the originally taught robot welding trajectory to be "corrected". The Seam ArcTracking function package can correct such deviations during the welding process, and the actual welding trajectory of the robot will be corrected to track the actual welding seam; if Use in conjunction with the Touch Sensor feature pack for best results.

When welding thick plates or fillet welds, the welding torch swings, and the rod elongation of the welding wire in the middle of the weld is different from that on both sides of the weld, and the rod elongation is different, resulting in the actual welding current and the set current. Differently, the shorter the rod elongation, the higher the actual current, and the longer the rod elongation, the lower the actual current.

Using this principle, the corresponding software processes the detected current changes and the position of the welding torch in real time, and then corrects the actual trajectory of the robot to ensure that the center line of the trajectory is always in the middle of the groove, or at the 45° position of the fillet weld. On the line; at the same time, ensure the consistency of the welding torch in the height direction.

When this function is activated, the feedback and processing frequency of relevant data can reach once every 12 microseconds, and the tracking accuracy is 0.1mm.

After the operator presses the start button, the workstation runs according to a pre-set program.

The spot laser scans and determines the position angle of the workpiece. The robot clamps the welding torch to the position of the welding seam. With the cooperation of the contact sensing function, the starting point of the welding seam is determined. The robot calculates the trajectory offset and starts welding. The welding process adopts swing welding, arc welding The tracking system will track the arc change and automatically correct the trajectory, eliminate the influence of the workpiece itself error and the welding deformation caused by the welding process, and ensure the best welding quality.

In addition to the above-described embodiments, the present invention may also have other embodiments. All technical solutions formed by equivalent replacement or equivalent transformation fall within the protection scope of the present invention.

Claims (9)

1. The special automatic welding machine for multilayer and multi-path welding seams on the circumference mainly comprises a gantry walking mechanism, a welding robot system, a welding positioner and other main parts;

the gantry type travelling mechanism is driven to rotate by an external shaft servo motor, can be freely programmed, and can be combined with a welding robot system to perform track interpolation; the robot can be in coordinated communication with the welding robot, and the walking speed and the acceleration can be adjusted;

each shaft of the robot in the welding robot system is provided with an intelligent anti-collision sensing device; the welding positioner has an arc tracking function system to sample current and voltage signals in swing welding in real time, and analyzes deformation caused by irregular grooves in blanking and in the welding process to obtain data modification robot paths;

the welding positioner is driven by an external shaft motor to turn over, and a programmer is arranged in the welding positioner.

2. The special automatic welding machine for the circumferential multilayer multi-pass welding seam according to claim 1, characterized in that: the welding robot system is provided with an absolute position encoder, and the position x/y/z and the angle A/B/C of the welding gun in space are memorized in real time.

3. The automatic welding method of the circumferential multilayer multi-channel welding line is characterized in that: according to the welding requirements, automatically setting each welding condition by using database resources, generating a multilayer welding program when the robot automatically welds, and automatically executing multilayer welding;

the welding robot system has the function of adjusting the angle between layers and the function of positioning an automatic welding gun; in the multi-layer and multi-pass welding process, unexpected interruption occurs in the welding process of the first or other welding lines, the program does not need to be edited or modified again, and the function of continuously completing the welding of other welding lines is achieved.

4. The method of automatically welding a circumferential multi-layer multi-pass weld of claim 3, wherein: when the robot contacts the charged welding wire with the workpiece according to a set program, a loop is formed between the welding wire and the workpiece, and the control system compares the current actual position with the position parameter during teaching; the new welding track is corrected by combining the current data with the teaching track, and the welding track is corrected; the position and the shape deviation of the workpiece enable the originally taught welding track of the robot to be corrected, the team Arc Tracking function package can correct the deviation in the welding process, the actual welding track of the robot is corrected, and the actual welding Seam is tracked; if the Touch Sensor function package is combined for use, the best effect can be achieved.

5. The method of automatically welding a circumferential multi-layer multi-pass weld of claim 3, wherein: when a thick plate or a fillet weld is welded, a welding gun swings, the rod elongation of a welding wire at the middle position of the weld is different from that at two sides of the weld, the actual welding current is different from the set current due to the difference of the rod elongation, the shorter the rod elongation is, the larger the actual current is, the longer the rod elongation is, and the smaller the actual current is.

6. The method of automatically welding a circumferential multi-layer multi-pass weld according to claim 3, wherein: corresponding software processes the detected current change and the position of a welding gun in real time so as to correct the actual track of the robot and ensure that the central line of the track is always in the middle of a groove or on a 45-degree position line of a fillet weld; and meanwhile, the consistency of the welding guns in the height direction is ensured.

7. The method of automatically welding a circumferential multi-layer multi-pass weld of claim 3, wherein: when the function is started, the feedback and processing frequency of related data can reach once every 12 microseconds, and the tracking precision is 0.1 mm.

8. The method of automatically welding a circumferential multi-layer multi-pass weld of claim 3, wherein: after the operator presses the start button, the workstation operates according to a preset program.

9. The method of automatically welding a circumferential multi-layer multi-pass weld of claim 3, wherein: the method comprises the following steps of scanning point laser and determining the position angle of a workpiece, clamping a welding gun by a robot to reach the position of a welding seam, determining the initial point of the welding seam under the coordination of a contact sensing function, calculating the track deviation by the robot and then starting welding, adopting swing welding in the welding process, enabling an arc tracking system to track the change of an arc and automatically correct the track, eliminating the influence caused by the error of the workpiece and the welding deformation generated in the welding process, and ensuring the optimal welding quality.

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