Electrical cabinet multi-angle collaborative welding equipment and welding method thereof

Abstract

The invention relates to the technical field of welding equipment, in particular to electrical cabinet multi-angle collaborative welding equipment and a welding method thereof.The electrical cabinet multi-angle collaborative welding equipment comprises a welding platform, a welding gun robot and a clamping mechanism, the welding gun robot and the clamping mechanism are installed on the welding platform, and the clamping mechanism is used for clamping and fixing a to-be-welded plate forming an electrical cabinet; the two welding gun robots are arranged, adjacent to-be-welded plates are in vertical butt joint, one welding gun robot is used for welding the inner sides of the adjacent to-be-welded plates, the other welding gun robot is used for welding the outer sides of the adjacent to-be-welded plates, welding guns of the two welding gun robots are arranged in a front-back staggered mode, and the distance between the front welding gun and the rear welding gun is 50-80 mm; and the current of the rear welding gun is reduced by 15%-20% compared with the current of the front welding gun. The invention aims to solve the problem that the phenomenon of single-side overheating is easily caused as a welding heat source is concentrated on one side and the heat source is concentrated on one side during single-angle welding on one side.

Description

Technical Field

[0001] The present invention relates to the technical field of welding equipment, and particularly to an electrical cabinet multi-angle collaborative welding equipment and its welding method. Background Art

[0002] At present, during welding, the welding area will experience a rapid heating and cooling process. In the heating stage, the metal in the weld and the nearby area expands, thus generating compressive stress. When cooling, the weld metal shrinks and is restricted by the already cooled part, and tensile stress will be formed again. When welding the bottom plate and the side plate of the electrical cabinet body frame at present, it is usually welded at a single angle on one side. The welding heat source is concentrated on one side. The concentration of the heat source on one side causes the metal temperature on that side to be significantly higher than the other side, and it is easy to cause the phenomenon of "unilateral overheating". Due to the large temperature difference between the two sides, when the metal on the high-temperature side expands and then cools and shrinks, it will cause the welded part to bend towards the heated side, seriously affecting the dimensional accuracy of the cabinet body, and further affecting the subsequent installation and use. Summary of the Invention

[0003] The purpose of the present invention is to provide an electrical cabinet multi-angle collaborative welding equipment and its welding method to solve the problem that when welding at a single angle on one side, the welding heat source is concentrated on one side, and it is easy to cause the phenomenon of "unilateral overheating".

[0004] To achieve the above purpose, the present invention provides the following technical solutions:

[0005] An electrical cabinet multi-angle collaborative welding equipment, characterized in that: it includes a welding platform, a welding gun robot, and a clamping mechanism. The welding gun robot and the clamping mechanism are installed on the welding platform. The clamping mechanism is used to clamp and fix the to-be-welded plate parts that make up the electrical cabinet and make the adjacent to-be-welded plate parts be vertically butted. The number of the welding gun robots is two groups. One group is used to weld the inner side of the adjacent to-be-welded plate parts, and the other group is used to weld the outer side of the adjacent to-be-welded plate parts. The welding guns of the two groups of welding gun robots are arranged in a front-back dislocation manner, and the front and rear welding guns maintain a spacing of 50 - 80 mm.

[0006] Preferably, the current of the rear welding gun is reduced by 15% - 20% compared with the current of the front welding gun.

[0007] Preferably, the number of the clamping mechanisms is two groups. The clamping mechanism includes a rotatable bearing platform, and a horizontally movable fixture is installed on the bearing platform.

[0008] Preferably, one of the fixtures is horizontally installed transversely, and the other fixture is horizontally installed vertically.

[0009] Preferably, the welding gun robot is installed with a line structured light sensor.

[0010] The multi-angle collaborative welding method for an electrical cabinet is carried out by using the multi-angle collaborative welding equipment for the electrical cabinet. The specific steps are as follows:

[0011] A. The clamping mechanism firmly clamps the plates to be welded of the side plate and the bottom plate of the electrical cabinet, maintaining a vertically butted state. The double welding gun robots cooperate in welding. One welding gun robot welds the inner side of the right-angle weld, and the other welding gun robot welds the outer side of the weld, completing the welding of the first L-shaped body plate of the electrical cabinet.

[0012] B. Similarly to step A, complete the vertical butt joint and double-robot collaborative welding of the plates to be welded of the side plate and the top plate of the electrical cabinet, forming the welding of the second L-shaped body plate of the electrical cabinet.

[0013] C. Vertically butt the edges of the two L-shaped body plates of the electrical cabinet to form two groups of vertical welds at diagonal positions. Use the double welding gun robots to cooperate in welding these two groups of vertical welds, and finally form a cabinet frame with four-sided welding.

[0014] Preferably, before step A, pre-treat the welded parts. Machine the edges at both ends of the plates to be welded on the side plate of the electrical cabinet to form mechanical bevels. The bevel angle is 60°±5°, and the root face is 1-2 mm. During welding, the bevel faces inward.

[0015] Preferably, in step C, first weld the vertical weld at the lower side. After welding is completed, turn the cabinet frame upside down so that the original vertical weld at the upper side is turned to the lower side, and then carry out welding.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] 1. This multi-angle collaborative welding equipment for an electrical cabinet, through the front and rear staggered arrangement of two groups of welding gun robots, the front gun first welds the inner right-angle area, and the rear gun welds on the outside. And the design of reducing the current of the rear welding gun by 15%-20% compared with the current of the front welding gun to form a stepped heat input. The shrinkage stress generated by the front gun can be offset by the local heating of the rear gun, and the heat distribution is made more reasonable.

[0018] 2. By the method of step-by-step welding of L-shaped plates and then combination, it supports modular production. And by first welding the vertical welds at diagonal positions and then welding the remaining vertical welds at diagonal positions, the advantage compared with welding in the order of left, right, down, and left in sequence is that it can reduce the cumulative error and prevent dimensional deviation in a certain step. The error will gradually amplify along the welding direction, while diagonal welding can effectively control the overall accuracy by step-by-step fixing of key points. Description of the Drawings

[0019] Figure 1 It is a schematic diagram of the welding form of step A of the present invention;

[0020] Figure 2Schematic diagram of the vertical butt joint of the edges of two L-shaped electrical cabinet body panels of the present invention;

[0021] Figure 3 Schematic diagram of welding after the cabinet body frame of the present invention is turned upside down. Detailed implementation manners

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0023] Please refer to Figures 1 to 3 , the present invention provides a technical solution.

[0024] An electrical cabinet multi-angle collaborative welding device includes a welding platform, a welding gun robot, and a clamping mechanism. The welding gun robot and the clamping mechanism are installed on the welding platform. The clamping mechanism is used to clamp and fix the to-be-welded plate members that make up the electrical cabinet, and make the adjacent to-be-welded plate members be vertically butted. The number of the welding gun robots is two groups. One group is used to weld the inner sides of the adjacent to-be-welded plate members, and the other group is used to weld the outer sides of the adjacent to-be-welded plate members. The welding guns of the two groups of welding gun robots are arranged in a front-back staggered manner, and the front and rear welding guns maintain a spacing of 50-80 mm. Among them, the front gun preferentially welds the inner right-angle area of the to-be-welded plate member of the electrical cabinet, and the rear gun is arranged in the outer area. The local heating of the rear gun offsets the shrinkage stress generated by the front gun.

[0025] The current of the rear gun is reduced by 15% to 20% compared with the current of the front gun. For example, the front gun is 100 A, and the rear gun is 80-85 A, forming a stepped heat input.

[0026] The front gun (inner side) completes the fusion of the main weld seam to form an initial thermal stress field, and the rear gun (outer side) follows closely. This "inner first and then outer, inner heat and outer compensation" mode enables the inner and outer materials to generate reverse stresses during cooling and shrinkage, offsetting the welding residual stress. The current of the rear gun is reduced by 15%-20%, reducing the heat input on the outer side and avoiding the outer side temperature exceeding the critical phase transformation temperature of the material. And because both the inner and outer sides are welded, the front gun (inner side) forms the main fusion zone, and the rear gun (outer side) performs dynamic compensation heating. Compared with welding only one side, which causes temperature concentration on one side, the heat distribution is more reasonable.

[0027] The welding torch robot uses a six-axis robotic arm with a composite welding torch mounted at the end. The repeat positioning accuracy is ±0.05 mm. Among them, the six-axis robotic arm achieves smooth movement through servo motors and high-precision reducers (such as RV reducers and harmonic gears), reducing the transmission clearance error and ensuring the trajectory accuracy. The composite welding torch supports multiple welding processes (such as MIG / MAG, TIG, plasma welding, etc.). By switching or combining different functions, it can adapt to the welding requirements of different materials (carbon steel, stainless steel, aluminum alloy) and thicknesses. The repeat positioning accuracy of ±0.05 mm ensures that the deviation between the actual position and the theoretical position of the welding torch end is controlled within 0.05 mm when the robot performs repetitive operations.

[0028] The number of the clamping mechanisms is two groups. The clamping mechanism includes a rotatable bearing table that achieves rotational movement through a servo motor and a high-precision reducer. A horizontally movable fixture is installed on the bearing table. The fixture can be a vacuum adsorption fixture, using a high-temperature resistant fluororubber suction cup (temperature resistance -40°C to +250°C). The surface of the suction cup is designed with serrations to enhance friction. The fixture realizes horizontal movement on the bearing table with the help of a lead screw-nut drive system. The lead screw is driven by a servo motor, and its rotational movement is converted into a linear translation of the fixture through a high-precision nut, ensuring that the positioning accuracy of the fixture in the horizontal direction can reach ±0.05 mm. One fixture is installed horizontally in the transverse direction, and the other fixture is installed horizontally in the vertical direction. The fixtures of the two groups of clamping mechanisms respectively clamp a plate to be welded, and then they are vertically butted at their ends through translation and rotation, and then the welding torch robot welds the formed weld seam.

[0029] The welding torch robot is equipped with a line structured light sensor (wavelength 650 nm, scanning frequency 200 Hz) to extract the three-dimensional coordinates of the weld seam in real time. The line structured light sensor is fixed in front of the welding torch by means of rigid connection or detachable installation, maintaining a certain distance from the welding torch. This installation method can obtain the three-dimensional information of the weld seam in advance, ensure the adjustment of the welding torch position before welding, avoid arc light interference, and adapt to the tracking of the weld seam, moving in coordination with the welding torch, calculating the deviation in real time through image processing and controlling the welding torch to correct the deviation.

[0030] The multi-angle collaborative welding method for electrical cabinets is as follows:

[0031] A. The clamping mechanism firmly clamps the plates to be welded of the electrical cabinet side plate and the bottom plate, maintaining a vertically butted state with a positioning error ≤0.05 mm. Two welding torch robots are used for collaborative welding. One welding torch robot welds the inner side of the right-angle weld seam, and the other welding torch robot welds the outer side of the weld seam to complete the welding of the first L-shaped electrical cabinet body plate;

[0032] Adopt MIG and MAG welding processes. The front gun (inner side) completes the fusion of the main weld to form an initial thermal stress field. The rear gun (outer side) starts 0.5 - 1 second later with the current reduced by 15% - 20% for dynamic compensation heating to offset the shrinkage stress of the front gun. The distance between the front gun and the rear gun is maintained at 50 - 80 mm, and the rear gun follows the front gun along the weld.

[0033] B. Similarly to step A, complete the vertical butt joint and double - robot collaborative welding of the plates to be welded on the side plate and top plate of the electrical cabinet to form the second L - shaped body plate of the electrical cabinet.

[0034] C. Vertically butt - joint the edges of the two L - shaped body plates of the electrical cabinet to form two sets of vertical welds at diagonal positions. Use a double - welding - gun robot to collaboratively weld these two sets of vertical welds to finally form a cabinet frame with four - side welding.

[0035] By the method of step - by - step welding of L - shaped plates and then combination, it supports modular production. And by welding the vertical welds at diagonal positions first and then the remaining diagonal - position vertical welds, the advantage compared with welding in the order of left - right - down - left is that it can reduce the cumulative error.

[0036] During welding, use a line - structured light sensor to scan the butt - joint area to generate the three - dimensional coordinates of the weld, and real - time feedback to the control system to correct the position deviation of the plate. The line - structured light sensor continuously collects the weld position, calculates the deviation through image - processing algorithms (such as edge detection + point - cloud matching), and dynamically adjusts the posture of the welding gun (with an accuracy of ±0.05 mm).

[0037] Before performing step A, clean the surface of the plates to be welded.

[0038] Pretreatment of the welded parts: Machine - process the edges at both ends of the plate to be welded on the side plate of the electrical cabinet to form a mechanical groove with a groove angle of 60°±5° and a root face of 1 - 2 mm. During welding, the groove faces inward.

[0039] After welding, when the natural cooling rate is insufficient, start the air - cooling system to accelerate uniform cooling.

[0040] After welding is completed, hammer the cabinet frame to release stress, or use an ultrasonic impact device (frequency 20 kHz, output energy 1.2 J / mm 2 ) to impact the weld along the 45° direction, with the impact frequency of 3 times / mm.

[0041] In step C, first weld the vertical weld on the lower side. After the welding is completed, turn the cabinet frame upside down so that the last vertical weld is transferred from the upper side to the lower side, and then perform the welding. Ensure that the inner welding torch faces downward during the welding process. Loosen the fixture, and manually turn the cabinet frame. It can also be achieved by loosening the fixture of the bottom plate and rotating the fixture of the side plate up and down. Ensure that when welding each vertical weld, it is welded downward, which can keep the welding molten pool in a relatively stable shape and position under the action of gravity, and can effectively avoid the problem of poor weld formation caused by the flow of molten pool metal.

[0042] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. Electrical cabinet multi-angle collaborative welding equipment, characterized by: It includes a welding platform, a welding gun robot, and a clamping mechanism. The welding gun robot and the clamping mechanism are installed on the welding platform. The clamping mechanism is used to clamp and fix the plates to be welded that constitute the electrical cabinet, and make adjacent plates to be welded vertically docked. The number of welding gun robots is two groups, one of which is used to weld the inner sides of adjacent plates to be welded, and the other group is used to weld the outer sides of adjacent plates to be welded. The welding guns of the two groups of welding gun robots are staggered front and back, and the front and rear welding guns maintain a distance of 50-80mm.

2. The multi-angle coordinated welding equipment for electrical cabinets according to claim 1 is characterized in that: The current of the rear welding gun is reduced by 15% to 20% compared with the current of the front welding gun.

3. The multi-angle coordinated welding equipment for electrical cabinets according to claim 1 is characterized in that: The number of the clamping mechanisms is two groups, and the clamping mechanisms include a rotatable bearing platform, on which a horizontally movable clamp is installed.

4. The multi-angle coordinated welding equipment for electrical cabinets according to claim 3 is characterized in that: One of the clamps is installed horizontally, and the other clamp is installed horizontally.

5. The multi-angle coordinated welding equipment for electrical cabinets according to claim 1 is characterized in that: The welding gun robot is equipped with a wired structured light sensor.

6. Multi-angle collaborative welding method for electrical cabinets, characterized in that: The multi-angle coordinated welding equipment for electrical cabinets as described in claim 1 is used, and the specific steps are as follows: A. The clamping mechanism firmly clamps the side panels and bottom panels of the electrical cabinet to be welded, maintaining a vertical docking state. A dual welding gun robot is used for collaborative welding. One welding gun robot welds the inside of the right-angle weld, and the other welding gun robot welds the outside of the weld, completing the welding of the first L-shaped electrical cabinet body panel; B. Follow step A to complete the vertical docking and double-robot collaborative welding of the side panels and top panels of the electrical cabinet to form the second L-shaped electrical cabinet body panel welding; C. Vertically connect the edges of two L-shaped electrical cabinet panels to form two sets of vertical welds at diagonal positions. Use a dual welding gun robot to collaboratively weld these two sets of vertical welds to eventually form a cabinet frame with four sides welded.

7. The multi-angle coordinated welding method of an electrical cabinet according to claim 6 is characterized in that: Before proceeding to step A, pre-treat the weldment and perform mechanical groove processing on the edges of both ends of the side panel of the electrical cabinet to be welded. The groove angle is 60°±5°, the blunt edge is 1-2mm, and the groove faces inward during welding.

8. The multi-angle coordinated welding method for an electrical cabinet according to claim 6, characterized in that: In step C, the vertical weld located at the lower side is welded first. After the welding is completed, the cabinet frame is turned upside down so that the vertical weld originally located at the upper side is turned to the lower side, and then welding is performed.

Images