Double-sided efficient welding method for transverse fillet welding of thick plate

Abstract

The invention discloses a double-sided efficient welding method for transverse fillet welding of a thick plate, and belongs to the technical field of robot welding. The welding method comprises the following steps: S1, fixing a point-fixed 45-degree K-shaped groove T-shaped plate through a tool clamp; s2, the two welding robots are placed on the two sides of the 45-degree K-shaped groove correspondingly; s3, each welding robot uses a welding gun to conduct bottoming welding on the groove gap, the welding guns on the two sides are arranged front and back during bottoming, the front gun swings during welding, and the rear gun does not swing or swings; and S4, after bottoming is completed, each welding robot uses two welding guns to conduct filling and surface covering on the groove gap. And in the bottoming and filling processes, the welding guns on the two sides arc at the same time. The problem of poor bottoming fusion is solved by increasing the bottom fusion depth through electric arcs on the front side and the back side during bottoming, the back gouging procedure can be omitted, the welding efficiency is improved, meanwhile, the deposition efficiency is remarkably improved through introduction of four wires, and the welding efficiency is further improved.

Description

Technical Field

[0001] The invention belongs to the technical field of robot welding, and in particular relates to a double-sided high-efficiency welding method for thick plate transverse fillet welding. Background Art

[0002] At present, due to the restriction of the bottom plate at the position of the thick plate horizontal fillet welding, the welding groove form will choose K-type and single-sided V-shaped groove. In the welding process, a single-sided V-shaped groove is usually used for single-sided welding. The main problem after welding is welding deformation. Under the action of welding stress, the welding deformation is obvious and cannot be corrected in most cases. Relatively speaking, the K-shaped groove has a small filling volume, and the double-sided filling will limit the deformation and reduce the variable, so the K-type is selected. For the K-shaped groove, if you want to achieve root welding without clearing, the requirement for penetration is relatively high, requiring full penetration to eliminate the defect of incomplete fusion.

[0003] Among them, the base welding is very important. At present, the base welding technology for single-sided welding mainly adopts metal electrode gas shielded welding for base welding, but it is more sensitive to the depth of penetration. The greater the depth of penetration, the stronger the penetration, and it is easy to have defects such as welding through and welding leakage. The smaller the depth of penetration, the defects such as lack of fusion and lack of penetration will appear. Both of them cause serious harm to the use of the structure.

[0004] The traditional welding process uses arc welding and flux-cored CO2 gas shielded welding for welding. The main disadvantages of this welding process are: ① The deposition rate per unit time is low and the welding efficiency is low. ② It requires a high level of worker skills and is easily affected by the professional skill level of the welder, and the qualified rate is low. ③ The welding formation is poor, and the workload of appearance grinding and processing increases. The gas shielded welding (GMAW) backing and submerged arc welding (SAW) filling and capping welding processes are adopted. This welding process effectively avoids the disadvantages of the traditional process, increases the welding speed by 2 to 3 times, greatly improves the welding efficiency, has high appearance forming quality, effectively reduces the amount of appearance processing and grinding work, improves the welding construction conditions, improves safety, and plays a role in energy saving, consumption reduction, and efficiency improvement. However, the submerged arc welding of the K-type groove is difficult, and the back root cleaning is still required, and the root slag cleaning is difficult. In the subsequent welding process, welding defects such as unfusion and slag inclusion are prone to occur, and the welding position is limited.

[0005] Therefore, it is urgent to design a double-sided efficient welding method for thick plate horizontal fillet welding to solve the above-mentioned problems. Summary of the invention

[0006] The purpose of the present invention is to provide a double-sided efficient welding method for thick plate horizontal fillet welding, which has the advantages of eliminating the back root cleaning process, increasing the welding penetration, and realizing double-sided non-root cleaning horizontal fillet welding of thick plates, thereby solving the problems mentioned in the background technology.

[0007] To achieve the above-mentioned purpose, the specific technical scheme of a double-sided efficient welding method for thick plate horizontal fillet welding of the present invention is as follows:

[0008] A high-efficiency double-sided welding method for thick plate horizontal fillet welding comprises the following steps:

[0009] S1. Fix the 45°K-groove T-shaped plate with a fixture;

[0010] S2, two welding robots are placed on both sides of the 45° K-shaped groove;

[0011] S3. Each welding robot uses a welding gun to perform base welding on the groove gap. When doing base welding, the welding guns on both sides are placed front and back, and the front gun swings during welding, while the rear gun does not swing or swings;

[0012] S4. After the base is applied, each welding robot uses two welding guns to fill and cover the groove gap. During the base and filling process, the welding guns on both sides start arcing at the same time;

[0013] S5. After welding is completed, turn off the protective gas and the welding power supply.

[0014] Furthermore, the blunt edge of the groove of the second plate body is 2 mm, and the groove gap is 2-4 mm.

[0015] Furthermore, the welding system is equipped with a line laser sensor, which has a base adaptive function. When the welding gun moves to positions of different sizes of grooves, the welding process parameters can be adjusted through the adaptive function to compensate the weld. The welding process parameters include welding speed, wire feeding speed, swing amplitude, swing frequency, etc.

[0016] Furthermore, the welding gun includes a first welding gun, a second welding gun, a third welding gun and a fourth welding gun, the first welding gun and the third welding gun are connected to the welding robot at the first direction end, the second welding gun and the fourth welding gun are connected to the welding robot at the second direction end, a collaborative communication line is connected between the welding machines connected to the first welding gun and the third welding gun, and a collaborative communication line is connected between the welding machines connected to the second welding gun and the fourth welding gun.

[0017] Further, in S3, the first welding gun and the second welding gun are used for base application, and the interval between the first welding gun and the second welding gun is 20 mm to reduce interference between arcs.

[0018] Furthermore, during base welding, the parameters of the first welding gun are smaller than those of the second welding gun, and the first welding gun adopts swing welding, while the second welding gun does not swing.

[0019] Further, the welding wire angle of the first welding gun points to the positive welding direction, and the welding wire angle of the second welding gun points to the negative welding direction.

[0020] Further, in S4, the first welding gun, the second welding gun, the third welding gun and the fourth welding gun are used for filling and capping, and the double wire spacing between the first welding gun and the fourth welding gun is 15 mm, the double wire spacing between the third welding gun and the second welding gun is 15 mm, and the first welding gun, the second welding gun, the third welding gun and the fourth welding gun are arced at the same time.

[0021] Furthermore, during filling, the welders on both sides of the workpiece use the same welding parameters to ensure the same heat input and reduce the deformation of the workpiece.

[0022] The present invention has the following advantages: the present invention solves the problem of poor base fusion by increasing the bottom melting depth through the electric arcs on both sides during base fusion, and the root cleaning process can be omitted, thereby improving welding efficiency. At the same time, the introduction of four wires significantly increases the deposition efficiency, thereby further improving the welding efficiency. While greatly improving the welding efficiency, double-sided simultaneous welding changes the temperature field and stress field of the workpiece, so that the material has smaller deformation and better stress distribution. When double-sided welding is adopted, the deformation is significantly reduced or even eliminated, so the preset reverse deformation can be cancelled before welding, thereby greatly improving the production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of the welding work of the present invention;

[0024] Figure 2 It is a schematic diagram of the structure of the T-shaped plate of the present invention;

[0025] Markings in the figure: 1, first plate; 11, second plate; 12, groove; 2, welding gun; 21, first welding gun; 22, second welding gun; 23, third welding gun; 24, fourth welding gun. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0027] Those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present invention and form different embodiments. For example, in the claims, any one of the claimed embodiments may be used in any combination.

[0028] Please refer to the attached Figure 1 and attached Figure 2The invention describes a double-sided efficient welding method for thick plate transverse fillet welding.

[0029] At present, the traditional welding process uses arc welding and flux-cored CO2 gas shielded welding for welding. The main disadvantages of this welding process are: low deposition rate per unit time and low welding efficiency. It requires high skill levels of workers and is easily affected by the professional skill level of welders, and the qualified rate. The welding formation is poor, and the workload of appearance grinding and processing increases. The gas shielded welding (GMAW) backing and submerged arc welding (SAW) filling and capping welding processes are adopted. This welding process effectively avoids the disadvantages of traditional processes, increases the welding speed by 2 to 3 times, greatly improves the welding efficiency, has high appearance forming quality, effectively reduces the amount of appearance processing and grinding work, improves welding construction conditions, improves safety, and plays a role in energy saving, consumption reduction, and efficiency improvement. However, the submerged arc welding of K-type grooves is difficult, and back root cleaning is still required, and root slag cleaning is difficult. In the subsequent welding process, welding defects such as unfusion and slag inclusion are prone to occur, and the welding position is limited.

[0030] Therefore, this method comprises the following steps:

[0031] S1. Fix the 45°K-groove T-shaped plate with a fixture;

[0032] The T-shaped plate includes a first plate body 1 and a second plate body 11 .

[0033] Specifically, the groove 12 of the second plate body 11 is designed as a double-sided 45° K-type groove 12, the blunt edge is 2mm, the groove 12 gap is 2-4mm, and the thickness of the second plate is selected based on actual needs. Preferably, the thickness of the second plate body 11 is 50mm. In other embodiments of the present invention, the thickness of the second plate body 11 can also be other thicknesses.

[0034] Pre-treating the second plate 11 means mechanically grinding and cleaning the second plate 11. If conditions permit, alcohol and acetone cleaning may be performed. The material of the welding wire is selected according to the material of the workpiece to be welded. Preferably, the welding wire is ER50S-G welding wire.

[0035] After clamping is completed, conduct pre-welding inspection to check the shielding gas composition, flow, nozzle, and water-cooled box welding wire to avoid affecting the welding process.

[0036] S2, two welding robots are placed on both sides of the 45° K-shaped groove;

[0037] Preferably, the welding robot adjusts the position of the welding gun 2 by confirming the moving position through the linkage of the six axes including the X-axis, the Y-axis, the Z-axis and the X1-axis, the Y1-axis and the Z1-axis.

[0038] Specifically, each robot carries two welding guns 2 .

[0039] The welding gun 2 includes a first welding gun 21, a second welding gun 22, a third welding gun 23 and a fourth welding gun 24. The first welding gun 21 and the third welding gun 23 are connected to the welding robot at the first direction end A, and the second welding gun 22 and the fourth welding gun 24 are connected to the welding robot at the second direction end B. A collaborative communication line is connected between the welding machines connected to the first welding gun 21 and the third welding gun 23, and a collaborative communication line is connected between the welding machines connected to the second welding gun 22 and the fourth welding gun 24.

[0040] Specifically, the first welding gun 21 and the fourth welding gun 24 are located on the same straight line, and the second welding gun 22 and the third welding gun 23 are located on the same straight line.

[0041] Specifically, the first welding gun 21, the second welding gun 22, the third welding gun 23 and the fourth welding gun 24 are respectively connected to four independent power supplies, and the four independent power supplies can independently set welding process parameters according to requirements.

[0042] When the welding gun 2 moves to a position where the groove 12 is not the same size, the weld can be compensated by adaptive adjustment. Specifically, the corresponding relationship between the groove 12 gap, the groove 12 angle and the welding current is first established through process tests to avoid defects caused by too large or too small welding current. Since the welding current and the wire feeding speed are a unified relationship, the wire feeding speed is adjusted according to the changes in the groove 12 gap and the groove 12 angle to change the filling amount of the welding process. Based on the 10m / min wire feeding speed, an adjustment range of ±1m / min is set, which can cover the ±2mm gap under a fixed plate thickness.

[0043] S3. Each welding robot uses a welding gun to perform base welding on the groove gap. When doing base welding, the welding guns on both sides are placed front and back, and the front gun swings during welding, while the rear gun does not swing;

[0044] Preferably, in S3, the first welding gun 21 and the second welding gun 22 are used for base welding, and the interval between the first welding gun 21 and the second welding gun 22 is 20 mm to reduce interference between arcs. In other embodiments of the present invention, the third welding gun 23 and the fourth welding gun 24 can also be used for base welding, as long as it can be ensured that each welding robot uses one welding gun for base welding.

[0045] Under the protection of double-sided gas, the back root cleaning process is eliminated. The double arc improves welding efficiency and increases welding penetration, thus realizing double-sided non-root cleaning horizontal fillet welding of thick plates.

[0046] Specifically, during base welding, the distance between the first welding gun 21 and the second welding gun 22 is 20 mm. If the distance is too close, there will be serious arc interference. If the distance is too far, the molten pool of the front wire will have cooled when the rear wire is welded during the welding process, which may easily cause root unfusion defects.

[0047] Furthermore, during base welding, the parameters of the first welding gun 21 are smaller than those of the second welding gun 22. Specifically, during welding, the first welding gun 21 adopts "push" welding, and its welding wire angle points to the positive direction of welding, which can increase the welding width, while the second welding gun 22 adopts "pull" welding, and its welding wire angle points to the negative direction of welding, which can increase the penetration depth and ensure root penetration. During welding, the parameters of the first welding gun 2131 are smaller than those of the second welding gun 22. The second welding gun 22 uses a large current to penetrate the back of the weld to ensure the quality of base welding.

[0048] Preferably, during the base welding, the welding current of the first welding gun 21 is 250A, the welding current of the second welding gun 22 is 260A, the welding voltage of the first welding gun 21 is 30V, the welding voltage of the second welding gun 22 is 33V, and the base welding speed is preferably 30cm / min.

[0049] S4. After the base is completed, each welding robot uses two welding guns to fill and cover the groove 12 gap; during the base and filling process, the welding guns on both sides start arcing at the same time.

[0050] During filling welding, four wires are fed into the welding machine simultaneously and combined with the K-type groove 12, which further improves the filling efficiency and gives full play to the advantages of multi-arc high efficiency.

[0051] Further, in S4, the first welding gun 21, the second welding gun 22, the third welding gun 23 and the fourth welding gun 24 are used for filling and covering, and the interval between the first welding gun 21 and the fourth welding gun 24 is 15 mm, the interval between the third welding gun 23 and the second welding gun 22 is 15 mm, and the first welding gun 21, the second welding gun 22, the third welding gun 23 and the fourth welding gun 24 start arcing at the same time.

[0052] Specifically, the first welding gun 21 and the third welding gun 23 are located at the first direction end A and extend into the groove 12 at an angle of 22.5°, and the second welding gun 22 and the fourth welding gun 24 are located at the second direction end B and extend into the groove 12 at an angle of 22.5°.

[0053] Specifically, the distance between the two welding guns is controlled within 15mm to ensure the eutectic pool of the two wires. The welding gun angle is 15 degrees and should not be too large. If the two wires are too close, the arc cannot burn stably. If the welding gun angle is too large, the distance between the two wires will be reduced, which will also cause unstable arc.

[0054] Furthermore, during filling, the welders on both sides of the workpiece use the same welding parameters to ensure the same heat input and reduce the deformation of the workpiece.

[0055] Specifically, during filling welding, the front wire current is 320A and the rear wire current is 300A, the front wire voltage is 33V, and the rear wire voltage is 30V. The welding machines on both sides of the workpiece use the same welding parameters to ensure the same heat input and reduce the deformation of the workpiece. The welding speed is 90cm / min. The large front wire parameters can well turn out the previous coating and obtain better weld formation.

[0056] Specifically, the cover welding parameters are the same as the filling parameters, but in order to control the weld formation, a high welding speed is adopted as much as possible during the cover welding. Here, a welding speed of 120 cm / min is adopted to achieve good cover formation.

[0057] Specifically, the shielding gas is 18% carbon dioxide and 82% pure argon, and the gas flow rate used by the four welding guns is 15L / min.

[0058] Furthermore, during filling, the welders on both sides of the workpiece use the same welding parameters to ensure the same heat input and reduce the deformation of the workpiece.

[0059] S5. After welding is completed, turn off the protective gas and the welding power supply.

[0060] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A high-efficiency double-sided welding method for thick plate horizontal fillet welding, characterized in that: The following steps are involved: S1. Fix the 45°K-groove T-shaped plate with a fixture; S2, two welding robots are placed on both sides of the 45° K-shaped groove; S3. Each welding robot uses a welding gun to perform base welding on the groove gap. When doing base welding, the welding guns on both sides are placed front and back, and the front gun swings during welding, while the rear gun does not swing or swings; S4. After the base is completed, each welding robot uses two welding guns to fill and cover the groove gap. During the base and filling process, the welding guns on both sides start arcing at the same time.

2. The high-efficiency double-sided welding method for thick plate horizontal fillet welding according to claim 1 is characterized in that: The blunt edge of the groove of the second plate body is 2 mm, and the groove gap is 2-4 mm.

3. The high-efficiency double-sided welding method for thick plate horizontal fillet welding according to claim 1, characterized in that: The welding system is equipped with a line laser sensor and has a base adaptive function. When the welding gun moves to positions of different sizes of grooves, the welding process parameters can be adjusted through the adaptive function to compensate the weld. The welding process parameters include welding speed, wire feeding speed, swing amplitude, swing frequency, etc.

4. The high-efficiency double-sided welding method for thick plate horizontal fillet welding according to claim 1, characterized in that: The welding guns include a first welding gun, a second welding gun, a third welding gun and a fourth welding gun. The first welding gun and the third welding gun are connected to a welding robot at a first direction end, the second welding gun and the fourth welding gun are connected to a welding robot at a second direction end, a collaborative communication line is connected between the welding machines connected to the first welding gun and the third welding gun, and a collaborative communication line is connected between the welding machines connected to the second welding gun and the fourth welding gun.

5. The high-efficiency double-sided welding method for thick plate horizontal fillet welding according to claim 4 is characterized in that: In S3, the first welding gun and the second welding gun are used for base application, and the interval between the first welding gun and the second welding gun is 20 mm to reduce interference between arcs.

6. The high-efficiency double-sided welding method for thick plate horizontal fillet welding according to claim 5, characterized in that: During base welding, the parameters of the first welding gun are smaller than those of the second welding gun, and the first welding gun adopts swing welding, while the second welding gun does not swing.

7. The high-efficiency double-sided welding method for thick plate horizontal fillet welding according to claim 5, characterized in that: The welding wire angle of the first welding gun points to the positive welding direction, and the welding wire angle of the second welding gun points to the negative welding direction.

8. The high-efficiency double-sided welding method for thick plate horizontal fillet welding according to claim 4, characterized in that: In S4, the first welding gun, the second welding gun, the third welding gun and the fourth welding gun are used for filling and covering, and the double wire spacing between the first welding gun and the fourth welding gun is 15 mm, the double wire spacing between the third welding gun and the second welding gun is 15 mm, and the first welding gun, the second welding gun, the third welding gun and the fourth welding gun are arced at the same time.

9. The high-efficiency double-sided welding method for thick plate horizontal fillet welding according to claim 1, characterized in that: During filling, the welders on both sides of the workpiece use the same welding parameters to ensure the same heat input and reduce deformation of the workpiece.

10. The high-efficiency double-sided welding method for thick plate horizontal fillet welding according to claim 1, characterized in that: It also includes S5. After welding is completed, turn off the protective gas and the welding power supply.

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