P + T automatic welding system and method suitable for square and round tank

Abstract

The invention relates to a welding system for a tank body, in particular to a P + T automatic welding system and method suitable for a square and round tank body, and aims at solving the problems that an existing circular seam welding method for the square and round tank body is tedious in step, consumes time and manpower, is poor in weld seam appearance forming and is high in repair rate. The system comprises a tank body clamping displacement assembly, a robot assembly and an AGV moving trolley. The tank body clamping displacement assembly comprises a displacement machine moving ground rail, two head and tail frame servo moving mechanisms arranged on the displacement machine moving ground rail, head and tail frame robot displacement machines arranged on the two head and tail frame servo moving mechanisms correspondingly, and a displacement machine control system electrically connected with the two head and tail frame servo moving mechanisms correspondingly. The robot assembly comprises a heavy-load robot moving ground rail and a welding robot. The two welding robots are each provided with a welding gun combination, and each welding gun combination comprises a plasma welding gun and an argon tungsten-arc welding gun.

Description

Technical Field

[0001] The invention relates to a welding system for a tank body, and in particular to a P+T automatic welding system and method suitable for square and round tank bodies. Background Art

[0002] See also Figure 2 and Figure 3 The square round tank body includes a square round cylinder and special-shaped heads respectively arranged at both ends of the square round cylinder. It has the advantages of large volume, high load capacity, light weight, high safety and zero residual liquid unloading after loading the medium. The processing of the square round tank body has a crucial impact on its quality, among which the circumferential seam welding between the head and the cylinder is an important part of the processing process.

[0003] At present, there are two mainstream welding methods for the circumferential seam welding of square and round tank bodies: one is the manual gas shielded double-sided welding method, and the other is the special machine plasma welding method of imitation form. The manual gas shielded double-sided welding method includes, in sequence, making grooves for the circumferential seam inside the tank body, grinding the grooves, manual gas shielded welding inside the tank body, root cleaning outside the tank body, grinding, manual gas shielded welding outside the tank body, self-inspection, weld grinding, flaw detection, and defect repair. The special machine plasma welding method of imitation form includes, in sequence, grinding the welding part, setting a back protection gas hood inside the tank body, plasma profiling welding, self-inspection, weld appearance grinding, flaw detection, and defect repair.

[0004] However, the manual gas shielded double-sided welding method is cumbersome, time-consuming and labor-intensive. Moreover, since the welding process is manually operated, it is easy to cause the weld appearance to be poor, which requires a lot of weld grinding operations later. At the same time, in order to ensure penetration, the consumption of welding wire is large, and the weld is inspected by X-ray, which has many defects and a high rework rate.

[0005] The special plasma welding of the copying type belongs to the automatic welding of the copying plasma special machine. The control during welding is manually intervened. The centering and alignment of the weld need to be adjusted manually. The height of the welding gun from the welded part needs to be adjusted manually during the welding process. During the rotation welding of the container, the welding position is constantly changing, and the posture of the welding gun remains unchanged, which can easily lead to uphill welding and downhill welding when welding the four small arc corners of the square round tank body, resulting in defects such as poor weld appearance and high rework rate. Summary of the invention

[0006] The purpose of the present invention is to solve the problems of complicated steps, time-consuming and labor-intensive, poor weld appearance and high rework rate in the existing circumferential seam welding method for square and round tank bodies, and to provide a P+T automated welding system and method for square and round cross-section special-shaped containers, wherein P stands for plasma arc welding (PAW) and T stands for argon arc welding (TIG).

[0007] To achieve the above purpose, the technical solution provided by the present invention is:

[0008] A P+T automatic welding system suitable for a square round tank body, the square round tank body comprising a square round cylinder body and special-shaped heads respectively arranged at both ends of the square round cylinder body, and the special features thereof are:

[0009] It includes a tank clamping and displacement assembly, a robot assembly for welding, and an AGV mobile vehicle for transporting square and round tanks;

[0010] The tank body clamping position changing assembly comprises a positioner moving ground rail, two head and tail frame servo moving mechanisms arranged on the positioner moving ground rail, two head and tail frame robot positioners respectively arranged on the two head and tail frame servo moving mechanisms, and a positioner control system respectively electrically connected to the two head and tail frame servo moving mechanisms; the two head and tail frame servo moving mechanisms can both move along the positioner moving ground rail;

[0011] The robot assembly includes a heavy-load robot moving track, two robot moving systems arranged on the heavy-load robot moving track, two welding robots respectively arranged on the two robot moving systems, and a welding power supply system and a robot control system respectively electrically connected to the two robot moving systems; both robot moving systems can move along the heavy-load robot moving track;

[0012] The two head and tail frame robot positioners are both provided with a rotatable multi-claw clamping system, and the ends of each claw of the two multi-claw clamping systems are facing inwards, and the number of claws of the multi-claw clamping system Z is ≥ 4; the multi-claw clamping system is used to clamp and rotate the opposite round tank body;

[0013] The two welding robots are both provided with a welding gun assembly, which comprises a plasma welding gun and a tungsten inert gas arc welding gun.

[0014] Furthermore, two AGV mobile trolley lifting devices for controlling the height of the square round tank body are arranged in parallel on the upper surface of the AGV mobile trolley, and each of the AGV mobile trolley lifting devices includes a lifting plate and a scissors for controlling the lifting of the lifting plate;

[0015] The upper surface of each lifting plate is provided with two V-shaped lifting inclined plates for lifting, bearing and limiting the square round tank body.

[0016] Furthermore, the robot assembly also includes a fume purification system respectively arranged on the two welding robots;

[0017] The welding gun assembly is provided with a tracking device connected to the robot control system, and the tracking device is used to monitor the running track of the welding gun assembly; the tracking device is a laser tracker or a camera.

[0018] Furthermore, the robot assembly also includes a welding wire cylinder respectively arranged on the two robot moving systems for providing welding wire to the two welding gun combinations, and the diameter of the welding wire in the welding wire cylinder is 1 mm or 1.2 mm.

[0019] Furthermore, Z=4.

[0020] At the same time, the present invention also provides a P+T automatic welding method suitable for square and round tank bodies, which adopts the above-mentioned P+T automatic welding system suitable for square and round tank bodies, and its special feature is that it includes the following steps:

[0021] Step 1: Pre-weld the special-shaped heads at both ends of the square cylinder by spot welding to obtain the square cylinder intermediate body and place it in the first fixed position. Then the operator enters the inside of the square cylinder intermediate body from the manhole, and sets a back argon protective cover at the two annular seams. After completion, the operator comes out from the manhole;

[0022] Step 2: The AGV mobile vehicle arrives at the first fixed position, and then carries the square round tank intermediate onto it and transports it to the welding position;

[0023] Step 3, when the square round tank intermediate reaches the welding position, the positioner control system controls the two head and tail frame servo moving mechanisms to move the first preset distance L1 in opposite directions along the positioner moving ground rail, and then the AGV mobile car moves the square round tank intermediate to the first preset position, and finally the head and tail frame servo moving mechanisms move the second preset distance L2 toward each other along the positioner moving ground rail, so that the multi-claw clamping systems on the two head and tail frame robot positioners jointly clamp and fix the square round tank intermediate; wherein, 2L1>L, 2L1-2L2=L, and L is the length of the square round tank;

[0024] Step 4: Move the AGV to the second preset position and wait;

[0025] Step 5, the two robot control systems respectively control the two robot moving systems to move the two welding robots to the preset positions respectively, and then the two welding robots respectively find the positions of the two annular seams and adjust the postures of the welding gun assemblies;

[0026] Step 6: The two head and tail frame robot positioners start to control the multi-claw clamping system to drive the square round tank body intermediate body to rotate synchronously, and the rotation linear speed of the square round tank body intermediate body at the annular seam is a constant value, and then the two welding guns start to weld the annular seam;

[0027] Step 7: After the two head and tail frame robot positioners control the multi-claw clamping system to drive the square round tank body intermediate body to rotate synchronously, the welding is completed, and the two welding robots move to the initial position to obtain the square round tank body;

[0028] Step 8: Move the AGV mobile car from the second preset position to the first preset position below the square round tank body, lift the square round tank body, and then the two head and tail frame robot positioners control the multi-claw clamping system to release and move the third preset distance in the back direction;

[0029] Step 9: The AGV mobile vehicle transports the square-shaped tank body to the second fixed position, and then the operator enters the square-shaped tank body through the manhole, takes out the two back argon protective covers and comes out from the manhole to complete the P+T automated welding suitable for the square-shaped tank body.

[0030] Furthermore, step 6 is specifically as follows:

[0031] The two head and tail frame robot positioners start to control the multi-claw clamping system to drive the square round tank body middle body to rotate synchronously, and the rotation linear speed of the square round tank body middle body at the annular seam is a constant value, and then the two plasma welding guns start to weld the annular seam; at the same time, the smoke purification system purifies the generated dust, the welding wire drum replenishes the welding wire in real time, and the tracking device monitors the running trajectory of the two plasma welding guns;

[0032] Step 7 is as follows:

[0033] After the two head and tail frame robot positioners control the multi-claw clamping system to drive the square round tank body intermediate body to rotate synchronously for one circle, the welding is completed, and the two welding robots move to the initial position to obtain the square round tank body.

[0034] Furthermore, step 6 is specifically as follows:

[0035] The two head and tail frame robot positioners start to control the multi-claw clamping system to drive the square round tank body middle body to rotate synchronously, and the rotation linear speed of the square round tank body middle body at the annular seam is constant. Then the two plasma welding guns and tungsten inert gas welding guns start to weld the annular seam in turn, and each welding gun welds one circle. At the same time, the smoke purification system purifies the generated dust, the welding wire drum replenishes the welding wire in real time, and the tracking device monitors the running trajectory of the two plasma welding guns and tungsten inert gas welding guns.

[0036] Step 7 is as follows:

[0037] After the two head and tail frame robot positioners control the multi-claw clamping system to drive the square-round tank body intermediate body to rotate synchronously for two weeks, the welding is completed, and the two welding robots move to the initial position to obtain the square-round tank body.

[0038] Furthermore, step 2 is specifically as follows:

[0039] The AGV mobile trolley arrives at the first fixed position, controls the lifting plate and the lifting inclined plate to rise, carries the square round tank intermediate body thereon, and transports the square round tank body to the welding position;

[0040] Step 8 is as follows:

[0041] The AGV mobile car is moved from the second preset position to the first preset position below the square round tank body, and the lifting plate and the lifting inclined plate are controlled to rise to lift the square round tank body. Then the two head and tail frame robot positioners control the multi-claw clamping system to release and move back to the third preset distance.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] 1. The present invention provides a P+T automatic welding system suitable for square and round tanks. The two multi-claw clamping systems can move along the movable ground rail of the positioner driven by the head and tail frame servo moving mechanism and the head and tail frame robot positioner, and can accurately clamp the square and round tanks and adjust their posture, thereby improving the accuracy of welding;

[0044] 2. The present invention provides a P+T automatic welding system suitable for square-circular tanks, comprising two welding robots. The two welding robots can move along the heavy-load robot moving track driven by the robot moving system, and can weld two annular seams at the same time, with higher welding efficiency and less time consumption; and the welding robots only weld on the outside of the square-circular tank, and do not need to enter the inside for welding, thus saving manpower and material resources;

[0045] 3. The present invention provides a P+T automatic welding system suitable for square and round tanks. The AGV mobile trolley is provided with an AGV mobile trolley lifting device and a lifting inclined plate, which is convenient for lifting, carrying, limiting and transporting the square and round tanks, and has high safety and accuracy.

[0046] 4. The present invention provides a P+T automatic welding system suitable for square and round tanks. Both welding robots are equipped with plasma welding guns and tungsten inert gas welding guns. According to the requirements of products and users, only plasma welding or plasma welding + tungsten inert gas welding can be performed. The system has a wide range of applications. At the same time, the welding wire drum can feed the wire in real time during the welding process, and the system has a high degree of integration.

[0047] 5. The P+T automatic welding system for square and round tanks provided by the present invention has a beautiful annular seam of the welded square and round tanks. The inside of the weld is 100% radiographically inspected according to the NB / T47013 standard, and the inspection result is not lower than AB level. After the tank is completed, the water pressure test is qualified, and the qualified level is not lower than level II, which means good quality.

[0048] 6. The present invention provides a P+T automated welding method suitable for square and round tank bodies. The entire system starts with the AGV mobile car taking the square and round tank bodies, and after the welding of the square and round tank bodies is completed, the AGV mobile car transports the square and round tank bodies to the designated location. The entire process is automatically controlled, does not require manual intervention, and is highly efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a structural schematic diagram of an embodiment of a P+T automatic welding system applicable to a square-round tank body according to the present invention;

[0050] Figure 2 It is the main view of the existing square round tank body;

[0051] Figure 3 It is a side view of the existing square round tank body;

[0052] Figure 4 It is a structural schematic diagram of an AGV mobile vehicle in an embodiment of a P+T automated welding system suitable for square and round tanks of the present invention;

[0053] Description of reference numerals:

[0054] 1-head and tail frame servo moving mechanism, 2-head and tail frame robot positioner, 3-multi-claw clamping system, 4-square and round tank, 5-smoke purification system, 6-welding robot, 7-positioner control system, 8-positioner mobile ground rail, 9-welding power supply system, 10-robot mobile system, 11-AGV mobile trolley, 12-AGV mobile trolley lifting device, 1201-lifting plate, 1202-scissors fork, 1203-lifting inclined plate, 13-welding wire tube, 14-welding gun combination, 15-heavy load robot mobile ground rail, 16-robot control system, 101-circular seam. DETAILED DESCRIPTION

[0055] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0056] The square-round tank body 4 welded in this embodiment includes a square-round cylinder and special-shaped heads respectively arranged at both ends of the square-round cylinder. The parameter requirements are shown in Table 1:

[0057] Table 1 Parameter requirements of the square round tank body in this embodiment

[0058]

[0059] Other requirements:

[0060] Shielding gas requirements: Shielding gas uses Ar (95vol%) + H2 (5vol%) or Ar (99.99vol%);

[0061] Weld surface treatment requirements: Clean oil, burrs and other impurities within 20mm on both sides of the weld.

[0062] Tank assembly requirements: The misalignment of the assembly is ≤0.5mm, and the maximum is no more than 10% of the tank wall thickness δ; the weld gap is ≤0.5mm.

[0063] Spot welding requirements: Use TIG welding to fix the workpiece, the welding spot length is about 5mm, and the spot welding spacing is 50-100mm.

[0064] See also Figure 1 A P+T automated welding system suitable for a square-shaped tank body includes a tank body clamping and displacement assembly, a robot assembly for welding, and an AGV mobile vehicle 11 for transporting a square-shaped tank body 4;

[0065] The tank body clamping position changing assembly comprises a positioner moving ground rail 8, two head and tail frame servo moving mechanisms 1 arranged on the positioner moving ground rail 8, two head and tail frame robot positioners 2 respectively arranged on the two head and tail frame servo moving mechanisms 1, and a positioner control system 7 respectively electrically connected to the two head and tail frame servo moving mechanisms 1; the two head and tail frame servo moving mechanisms 1 can both move along the positioner moving ground rail 8;

[0066] The robot assembly includes a heavy-load robot moving track 15, two robot moving systems 10 arranged on the heavy-load robot moving track 15, two welding robots 6 respectively arranged on the two robot moving systems 10, a welding power supply system 9 and a robot control system 16 respectively electrically connected to the two robot moving systems 10, and a fume purification system 5 respectively arranged on the two welding robots 6 and a welding wire drum 13 arranged on the two robot moving systems 10 for providing welding wire to two welding gun assemblies 14; both robot moving systems 10 can move along the heavy-load robot moving track 15;

[0067] The two head and tail frame robot positioners 2 are both provided with a rotatable multi-claw clamping system 3, and each claw end of the two multi-claw clamping systems 3 faces inward. In this embodiment, the number of claws Z=4, and can actually be 6, 8, etc. to meet different working conditions; the multi-claw clamping system 3 is used to clamp and rotate the other round tank body 4;

[0068] The two welding robots 6 are both provided with a welding gun assembly 14 , which includes a plasma welding gun and a tungsten inert gas arc welding gun.

[0069] See also Figure 4 Two AGV mobile trolley lifting devices 12 for controlling the height of the square round tank body 4 are arranged in parallel on the upper surface of the AGV mobile trolley 11. Each AGV mobile trolley lifting device 12 includes a lifting plate 1201 and a scissor 1202 for controlling the lifting and lowering of the lifting plate 1201. Two V-shaped lifting inclined plates 1203 are arranged on the upper surface of each lifting plate 1201 for limiting the position of the square round tank body 4. The advantage of such a setting is that it is convenient for lifting, carrying, limiting and transporting the square round tank body 4, and it is safe and accurate.

[0070] The welding gun assembly 14 is provided with a tracking device connected to the robot control system 16, and the tracking device is used to monitor the running track of the welding gun assembly 14; the tracking device is a laser tracker. The diameter of the welding wire in the welding wire tube 13 is 1 mm or 1.2 mm.

[0071] At the same time, this embodiment also provides a P+T automatic welding method suitable for square and round tank bodies, using the above-mentioned P+T automatic welding system suitable for square and round tank bodies, including the following steps:

[0072] Step 1: Pre-weld the special-shaped heads at both ends of the square cylinder by spot welding to obtain the square cylinder intermediate body and place it in the first fixed position. Then, the operator enters the inside of the square cylinder intermediate body from the manhole, and sets a back argon protective cover at the two annular seams 101. After completion, the operator comes out from the manhole;

[0073] Step 2, the AGV mobile vehicle 11 arrives at the first fixed position, and then carries the square round tank intermediate onto it and transports it to the welding position;

[0074] Step 3, when the square round tank intermediate reaches the welding position, the positioner control system 7 controls the two head and tail frame servo moving mechanisms 1 to move the first preset distance L1 in the opposite direction along the positioner moving ground rail 8, and then the AGV mobile car 11 moves the square round tank intermediate to the first preset position, and finally the head and tail frame servo moving mechanisms 1 move the second preset distance L2 toward each other along the positioner moving ground rail 8, so that the multi-claw clamping systems 3 on the two head and tail frame robot positioners 2 jointly clamp and fix the square round tank intermediate; wherein, 2L1>L, 2L1-2L2=L, L is the length of the square round tank 4;

[0075] Step 4, move the AGV mobile vehicle 11 to the second preset position and wait;

[0076] Step 5, the two robot control systems 16 respectively control the two robot moving systems 10 to move the two welding robots 6 to the preset positions respectively, and then the two welding robots 6 respectively find the positions of the two annular seams 101 and adjust the postures of the welding gun assemblies 14;

[0077] If plasma arc welding is used, steps 6 and 7 are:

[0078] Step 6 is as follows:

[0079] The two head and tail frame robot positioners 2 start to control the multi-claw clamping system 3 to drive the square round tank body intermediate body to rotate synchronously, and the rotation linear speed of the square round tank body intermediate body at the annular seam 101 is a constant value, and then the two plasma welding guns start to weld the annular seam 101; at the same time, the smoke purification system 5 purifies the generated dust, the welding wire drum 13 replenishes the welding wire in real time, and the tracking device monitors the running trajectory of the two plasma welding guns;

[0080] Step 7 is as follows:

[0081] After the two head and tail frame robot positioners 2 control the multi-claw clamping system 3 to drive the square round tank body intermediate body to rotate synchronously for one circle, the welding is completed, and the two welding robots 6 move to the initial position to obtain the square round tank body 4;

[0082] If plasma arc welding + argon arc welding is used, steps 6 and 7 are:

[0083] The two head and tail frame robot positioners 2 start to control the multi-claw clamping system 3 to drive the square round tank body intermediate body to rotate synchronously, and the rotation linear speed of the square round tank body intermediate body at the annular seam 101 is a constant value, and then the two plasma welding guns and the tungsten inert gas welding gun start to weld the annular seam 101 in turn, and each welding gun welds one circle; at the same time, the smoke purification system 5 purifies the generated dust, the welding wire barrel 13 replenishes the welding wire in real time, and the tracking device monitors the running trajectory of the two plasma welding guns and the tungsten inert gas welding gun;

[0084] Step 7 is as follows:

[0085] After the two head and tail frame robot positioners 2 control the multi-claw clamping system 3 to drive the square round tank body intermediate body to rotate synchronously for two weeks, the welding is completed, and the two welding robots 6 move to the initial position to obtain the square round tank body 4;

[0086] Step 8, the AGV mobile vehicle 11 is moved from the second preset position to the first preset position below the square round tank body 4, the lifting plate 1201 and the lifting inclined plate 1203 are controlled to rise, and the square round tank body 4 is lifted, and then the two head and tail frame robot positioners 2 control the multi-claw clamping system 3 to release and move backwards by a third preset distance;

[0087] Step 9, the AGV mobile car 11 transports the square-shaped tank body 4 to the second fixed position, and then the operator enters the square-shaped tank body 4 through the manhole, takes out the two back argon protective covers and comes out from the manhole to complete the P+T automated welding suitable for the square-shaped tank body.

[0088] This embodiment is conducive to the safe operation of workers, and the material path is clear and simple. The multi-claw clamping system 3 ensures accurate clamping or loosening. The two welding robots 6 work together, and the welding efficiency is high. The square round tank body 4 welded by this embodiment has a beautiful annular seam, and the inside of the annular seam 101 is 100% radiographically inspected according to the NB / T47013 standard, and the inspection result grade is not lower than AB grade; after the tank body is completed, the water pressure test is qualified, and the qualified level is not lower than Grade II, and the quality is good.

Claims

1. A P+T automatic welding system suitable for a square-round tank body, wherein the square-round tank body (4) comprises a square-round cylinder and special-shaped heads respectively arranged at both ends of the square-round cylinder, characterized in that: It comprises a tank body clamping and displacement assembly, a robot assembly for welding, and an AGV mobile vehicle (11) for transporting a square-shaped tank body (4); The tank body clamping position changing assembly comprises a positioner moving ground rail (8), two head and tail frame servo moving mechanisms (1) arranged on the positioner moving ground rail (8), two head and tail frame robot positioners (2) respectively arranged on the two head and tail frame servo moving mechanisms (1), and a positioner control system (7) respectively electrically connected to the two head and tail frame servo moving mechanisms (1); the two head and tail frame servo moving mechanisms (1) can both move along the positioner moving ground rail (8); The robot assembly comprises a heavy-load robot moving track (15), two robot moving systems (10) arranged on the heavy-load robot moving track (15), two welding robots (6) respectively arranged on the two robot moving systems (10), a welding power supply system (9) and a robot control system (16) respectively electrically connected to the two robot moving systems (10); the two robot moving systems (10) can both move along the heavy-load robot moving track (15); The two head and tail frame robot positioners (2) are both provided with a rotatable multi-claw clamping system (3), and each claw end of the two multi-claw clamping systems (3) faces inwards, and the number of claws Z of the multi-claw clamping system (3) is ≥4; the multi-claw clamping system (3) is used to clamp and rotate the other circular tank body (4); The two welding robots (6) are each provided with a welding gun assembly (14), wherein the welding gun assembly (14) comprises a plasma welding gun and a tungsten inert gas arc welding gun.

2. A P+T automatic welding system suitable for square and round tanks according to claim 1, characterized in that: Two AGV mobile trolley lifting devices (12) for controlling the height of the square-shaped tank body (4) are arranged in parallel on the upper surface of the AGV mobile trolley (11), and each of the AGV mobile trolley lifting devices (12) comprises a lifting plate (1201) and a scissors fork (1202) for controlling the lifting and lowering of the lifting plate (1201); The upper surface of each lifting plate (1201) is provided with two V-shaped lifting inclined plates (1203) for lifting, carrying and limiting the square round tank body (4).

3. A P+T automatic welding system suitable for square and round tanks according to claim 2, characterized in that: The robot assembly further comprises a fume purification system (5) respectively arranged on the two welding robots (6); The welding gun assembly (14) is provided with a tracking device connected to a robot control system (16), and the tracking device is used to monitor the running track of the welding gun assembly (14); the tracking device is a laser tracker or a camera.

4. The P+T automatic welding system suitable for square and round tanks according to claim 3 is characterized in that: The robot assembly also includes welding wire barrels (13) respectively arranged on the two robot moving systems (10) for providing welding wire to two welding gun assemblies (14), and the diameter of the welding wire in the welding wire barrels (13) is 1 mm or 1.2 mm.

5. The P+T automatic welding system suitable for square and round tanks according to claim 3 is characterized in that: Said Z=4.

6. A P+T automated welding method for square-round tank bodies, using a P+T automated welding system for square-round tank bodies as claimed in any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: pre-weld the special-shaped heads at both ends of the square cylinder by spot welding to obtain the square cylinder intermediate body and place it in the first fixed position. Then, the operator enters the inside of the square cylinder intermediate body through the manhole, and sets a back argon protective cover at two annular seams (101). After completion, the operator comes out from the manhole; Step 2, the AGV mobile vehicle (11) arrives at the first fixed position, then carries the square round tank intermediate onto it and transports it to the welding position; Step 3, when the square-shaped tank intermediate reaches the welding position, the positioner control system (7) controls the two head and tail frame servo moving mechanisms (1) to move in opposite directions along the positioner moving ground rail (8) by a first preset distance L1, and then the AGV moving vehicle (11) moves the square-shaped tank intermediate to the first preset position, and finally the head and tail frame servo moving mechanisms (1) move in opposite directions along the positioner moving ground rail (8) by a second preset distance L2, so that the multi-claw clamping systems (3) on the two head and tail frame robot positioners (2) jointly clamp and fix the square-shaped tank intermediate; wherein, 2L1>L, 2L1-2L2=L, and L is the length of the square-shaped tank (4); Step 4, moving the AGV mobile vehicle (11) to a second preset position and waiting; Step 5, the two robot control systems (16) respectively control the two robot moving systems (10) to move the two welding robots (6) to the preset positions respectively, and then the two welding robots (6) respectively find the positions of the two annular seams (101) and adjust the posture of the welding gun assembly (14); Step 6, the two head and tail frame robot positioners (2) start to control the multi-claw clamping system (3) to drive the square round tank body intermediate body to rotate synchronously, and the rotation linear speed of the square round tank body intermediate body at the annular seam (101) is a constant value, and then the two welding gun assemblies (14) start to weld the annular seam (101); Step 7: After the two head and tail frame robot positioners (2) control the multi-claw clamping system (3) to drive the square round tank body intermediate body to rotate synchronously and complete welding, the two welding robots (6) move to the initial position to obtain the square round tank body (4); Step 8, the AGV mobile vehicle (11) is moved from the second preset position to the first preset position below the square round tank body (4), and the square round tank body (4) is lifted, and then the two head and tail frame robot positioners (2) control the multi-claw clamping system (3) to release and move backwards by a third preset distance; Step 9, the AGV mobile vehicle (11) transports the square-shaped tank body (4) to the second fixed position, and then the operator enters the square-shaped tank body (4) through the manhole, takes out the two back argon protective covers and comes out from the manhole, completing the P+T automated welding suitable for the square-shaped tank body.

7. A P+T automatic welding method suitable for square and round tank bodies according to claim 6, characterized in that: Step 6 is as follows: The two head and tail frame robot positioners (2) start to control the multi-claw clamping system (3) to drive the square round tank body intermediate body to rotate synchronously, and the rotation line speed of the square round tank body intermediate body at the annular seam (101) is a constant value, and then the two plasma welding guns start to weld the annular seam (101); at the same time, the smoke purification system (5) purifies the generated dust, the welding wire barrel (13) replenishes the welding wire in real time, and the tracking device monitors the running trajectory of the two plasma welding guns; Step 7 is as follows: After the two head and tail frame robot positioners (2) control the multi-claw clamping system (3) to drive the square round tank body intermediate body to rotate synchronously for one circle, the welding is completed, and the two welding robots (6) move to the initial position to obtain the square round tank body (4).

8. The P+T automatic welding method for square and round tank bodies according to claim 6 is characterized in that: Step 6 is as follows: The two head and tail frame robot positioners (2) start to control the multi-claw clamping system (3) to drive the square-shaped tank body intermediate body to rotate synchronously, and the rotation line speed of the square-shaped tank body intermediate body at the annular seam (101) is constant, and then the two plasma welding guns and the tungsten inert gas welding gun start to weld the annular seam (101) in turn, and each welding gun welds one circle; at the same time, the smoke purification system (5) purifies the generated dust, the welding wire barrel (13) replenishes the welding wire in real time, and the tracking device monitors the running trajectory of the two plasma welding guns and the tungsten inert gas welding gun; Step 7 is as follows: After the two head and tail frame robot positioners (2) control the multi-claw clamping system (3) to drive the square round tank body intermediate body to rotate synchronously for two weeks, the welding is completed, and the two welding robots (6) move to the initial position to obtain the square round tank body (4).

9. A P+T automated welding method suitable for square and round tank bodies according to any one of claims 6 to 8, characterized in that: Step 2 is as follows: The AGV mobile trolley (11) reaches the first fixed position, controls the lifting plate (1201) and the lifting inclined plate (1203) to rise, carries the square round tank intermediate body thereon, and transports the square round tank body (4) to the welding position; Step 8 is as follows: The AGV mobile vehicle (11) (11) is moved from the second preset position to the first preset position below the square round tank body (4), and the lifting plate (1201) and the lifting inclined plate (1203) are controlled to rise to lift the square round tank body (4). Then, the two head and tail frame robot positioners (2) control the multi-claw clamping system (3) to release and move the system backward to a third preset distance.

Images