Vertical penetrating type double-shaft-shoulder friction stir welding equipment and method for longitudinal seam of storage box

Abstract

The invention relates to the technical field of friction stir welding, and provides vertical penetrating type double-shaft-shoulder friction stir welding equipment and method for a longitudinal seam of a storage box. The back synchronous supporting system is arranged in the welded part and is provided with a synchronous base plate; and the outer welding assembly is provided with an outer welding machine head and a pressing claw system, the pressing claw system can tightly press the welded part, and the outer welding machine head and a synchronous base plate are provided with a stirring tool and a static lower shaft shoulder cushion block correspondingly so that storage box longitudinal seam vertical penetrating type double-shaft-shoulder stirring friction welding operation can be achieved. The conventional stirring head and the static lower shaft shoulder cushion block are adopted, synchronous movement of the conventional stirring head and the static lower shaft shoulder cushion block in the welding direction is achieved through the two transmission systems, the defects of incomplete penetration, weak combination and the like of the root of a welding seam can be effectively avoided, longitudinal seam penetration type double-shaft-shoulder friction stir welding of the storage tank is achieved, and welding stability is improved.

Description

Technical Field

[0001] The invention relates to the technical field of friction stir welding, and in particular to a vertical penetrating double-shoulder friction stir welding device and method for a longitudinal seam of a tank. Background Art

[0002] Friction stir welding technology is widely used in the manufacturing of aerospace products, especially in the manufacturing of launch tanks. At present, full friction stir welds of launch tanks have been achieved. For the longitudinal seams of the barrel and shell sections of the tank, the length of the stirring needle used in conventional friction stir welding is generally less than the thickness of the workpiece to be welded, which can easily lead to welding defects such as incomplete penetration and weak connection at the root of the weld, posing a great potential risk. Although traditional double-shoulder friction stir welding can avoid the problem of weak connection and reduce the requirements for pre-welding assembly accuracy to a certain extent, double-shoulder friction stir welding has high requirements for stirring tools, and the stirring needle cannot use an inclination angle, and the heat input during the welding process is high.

[0003] Patent document CN105382405A discloses a device and method for stir friction welding with an auxiliary support of a stationary shoulder. Stir friction penetration welding is achieved by using a conventional stirring head and a stationary shoulder with a blind hole to move synchronously. This welding method can effectively avoid the defect of unwelded joints. However, this welding device is only suitable for laboratory test plate welding and cannot achieve vertical stir friction welding. For the curved parts of aerospace tanks, this device and method are not applicable. Summary of the invention

[0004] In view of the defects in the prior art, the object of the present invention is to provide a vertical penetrating double-shoulder friction stir welding device and method for the longitudinal seam of a tank.

[0005] According to the present invention, a vertical penetration double-shoulder friction stir welding device for a tank longitudinal seam is provided, comprising: Parts and tooling assembly, used to fix the parts to be welded; A back synchronous support system is arranged inside the welded part and is provided with a synchronous pad to support the welded part; The external welding assembly comprises an external welding head and a pressure claw system, wherein the pressure claw system can press the welded parts. The external welding head and the synchronous pad are respectively provided with a stirring tool and a stationary lower shoulder pad to realize the vertical penetrating double shoulder friction stir welding operation of the longitudinal seam of the tank.

[0006] Preferably, the part tooling assembly includes a tooling base, an internal welding tooling, and an external welding tooling, the bottoms of the internal welding tooling and the external welding tooling are both configured on the tooling base, the external welding tooling is arranged along the circumference of the internal welding tooling and the welded parts are arranged between the internal welding tooling and the external welding tooling, the external welding tooling is fixed and cooperates with the internal welding tooling to clamp the welded parts.

[0007] Preferably, the back synchronous support system includes an internal support system, a synchronous pad, an internal transmission mechanism, an internal column and an internal base; The internal column is arranged on the internal base, and the internal support system is configured on the internal column so that the internal column and the internal welding tooling form a whole, and the internal transmission mechanism can drive the synchronous pad to achieve synchronous movement with the external welding head.

[0008] Preferably, the internal support system comprises a plurality of hydraulic cylinders, and the plurality of hydraulic cylinders are mounted on the internal columns, and the internal columns and the internal welding tooling are integrated into a whole by the hydraulic cylinders.

[0009] Preferably, the external welding assembly includes an external welding head, a pressure claw system, a top tensioning system, an external welding transmission system, an external welding column, and an external welding base, and the external welding head is arranged at the bottom of the external welding column and is equipped with a stirring tool; The clamping claw system is arranged on the side of the outer welding column and faces the welded part; the two ends of the top tensioning system are respectively connected to the inner column and the outer welding column and can tighten the inner column and the outer welding column.

[0010] Preferably, the external welding head adopts a mechanical external spindle motor; The top tensioning system is driven by a winch on the top of the externally welded column to achieve the rotational movement of the tensioning arm.

[0011] Preferably, both the inner column and the outer welding column are equipped with a transmission system and the two transmission systems belong to the same control system, which can realize the synchronous movement of the outer welding head and the synchronous pad.

[0012] Preferably, the external welding head is provided with a laser circular scanning device, and the laser circular scanning device adopts a laser circular scanning type stir friction welding process detection system, including a laser ranging sensor, and the laser ranging sensor can rotate around the stirring tool, and obtain the spatial three-dimensional coordinates of the monitoring point through the encoder in the servo motor and the height of the detection point, and can design a parameter extraction algorithm for online detection of the inclination angle of the stirring tool, the shoulder pressure amount and the weld deviation during the welding process.

[0013] Preferably, the laser ring scanning device adopts a pressure detection elastic body, utilizes a strain gauge bridge to convert the strain signal into an electrical signal, and establishes a theoretical connection between the signal and the upsetting force, so as to detect and analyze the upsetting force information of the welding process and perform constant pressure adaptive control.

[0014] According to the present invention, a vertical penetrating double-shoulder friction stir welding method for a tank longitudinal seam comprises the following steps: S1: Preliminary preparation: Assemble the stirring tool on the external welding head, fix the static lower shoulder pad on the synchronous pad, observe whether the center of the stirring needle of the stirring tool is placed 0 to 3 mm away from the center of the waist-shaped hole of the static lower shoulder pad, start the transmission system, move the stirring tool and the static lower shoulder pad along the welding direction under no-load state, and observe whether the two are synchronized during the process; S2: Parts assembly: The welding edges of the welded parts are fused and positioned in sections to form a complete cylinder. The welded parts are assembled between the inner welding fixture and the outer welding fixture and clamped. The top tensioning system is started to tighten the inner column and the outer welding column. Then the internal support system is started to support the welded parts outwards. The pressing claw system is then started to press the welded parts from the outside. At this time, the assembly is completed; S3: Positioning welding: After ensuring that the stirring tool and the stationary lower shoulder pad move synchronously, remove the stirring tool and the stationary lower shoulder pad, replace the flat pad without holes and the positioning welding stirring tool for positioning welding, ensure that the welding part of the welded parts is located at the center of the positioning welding stirring tool, and the surface of the flat pad is in close contact with the lower surface of the welded parts, input the selected welding process parameters into the control system, adjust the inclination angle of the positioning welding stirring tool, start the equipment for positioning welding, and the welding method is that the welded parts are fixed, and the positioning welding stirring tool and the flat pad move synchronously along the welding direction; S4: Formal welding: Remove the positioning welding stirring tool and flat pad, replace them with the stirring tool and the stationary lower shoulder pad, and move them to the welding starting position. Change the welding process parameters in the control system of the equipment. After centering again, start the stir friction welding equipment for formal welding. The welding method is that the welded parts are fixed, and the stirring tool and the stationary lower shoulder pad move synchronously along the welding direction. During the process, the pressing amount can be adjusted according to the actual situation.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention adopts a conventional stirring head and a stationary lower shoulder pad to replace the traditional double-shoulder stirring tool. The conventional stirring head and the stationary lower shoulder pad are synchronously moved along the welding direction through two transmission systems, thereby realizing the penetrating double-shoulder friction stir welding of the longitudinal seam of the storage tank, which can effectively avoid the formation of defects such as incomplete welding at the root of the weld and weak bonding; filling material is added to the waist-shaped hole of the stationary lower shoulder pad to eliminate the defects at the beginning of the penetrating friction stir weld.

[0016] 2. The present invention is aimed at parts with a thickness of more than 6 mm, and stir friction double-sided welding is usually used for welding. The assembly and welding time is doubled compared to single-sided welding, and the back weld needs to be polished after welding. The use of penetrating stir friction welding can achieve single welding forming, and there is no need to polish the back weld, which greatly saves product production time.

[0017] 3. The present invention addresses the problems of traditional double-shoulder stirring tools, such as high difficulty in manufacturing, high requirements for the dimensional accuracy of the upper and lower axis spacing, cumbersome centering of the stirring tool during welding, inability to adjust the pressure amount and inclination angle, short life of the stirring tool, high heat generation during welding, and narrow welding process window. The penetrating double-shoulder friction stir welding stirring tool used in the present invention is the same as the traditional stirring tool, and is relatively simple to control during the welding process. At the same time, the pressure amount and inclination angle can be adjusted, which reduces the difficulty of designing and controlling the stirring tool to a certain extent and further improves the joint quality.

[0018] 4. Compared with conventional vertical friction stir welding longitudinal seam equipment, the equipment in the present invention adds a synchronous pad on the back support system. When a stationary lower shoulder pad with holes is used, vertical penetrating friction stir welding can be achieved; when a flat pad without holes is used, traditional vertical friction stir welding can be achieved. Therefore, the welding mode can be switched to realize the multifunctional operation of the welding equipment and meet the welding needs in different situations.

[0019] 5. The present invention is based on multi-parameter perception, intelligent tool holder perception and end motion detection during the laser circular scanning friction stir welding process, and the detection and online intelligent control of the downward pressure / downward force, inclination angle and weld deviation during the welding process. It can realize the longitudinal seam penetration double-shoulder friction stir welding process of tank shell sections, cylinder sections, etc., eliminate potential welding risks such as incomplete welding and weak bonding, and ultimately obtain high-quality welded joints, achieving a breakthrough in the intelligent control technology of the friction stir welding process of complex structural parts, improving welding stability, and obtaining high-quality welds. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings: Figure 1 It is a front structural schematic diagram of the present invention; Figure 2 It is a schematic diagram of the top view of the structure of the present invention; Figure 3 It is a front structural schematic diagram of the parts and tooling assembly; Figure 4 It is a schematic diagram of the top view of the structure of the parts and tooling assembly; Figure 5It is a schematic diagram of the front structure of the back synchronous support system; Figure 6 It is a side structural schematic diagram of the back synchronous support system; Figure 7 It is a schematic diagram of the placement position of the filling material in the waist-shaped hole of the stationary lower shoulder pad; Figure 8 It is a schematic diagram of the side structure of the external welding component; Fig. 9 It is a top view schematic diagram of the stationary lower shoulder pad; Fig.10 It is a schematic diagram of the cross-sectional structure of the stationary lower shoulder pad.

[0021] The figure shows: Parts and tooling assembly 1; Back synchronous support system 2; External welding assembly 3; Tooling base 4; Internal welding tooling 5; External welding tooling 6; Welded parts 7; Internal support system 8; Synchronous pad 9; Internal transmission mechanism 10; Internal column 11; Internal base 12; Stationary lower shoulder pad 13; Waist-shaped hole 131; External welding machine head 14; Claw system 15; Top tensioning system 16; External welding transmission system 17; Externally welded columns 18; External welding base 19; Stirring tool 20; Filling material 21; Laser ring scanning device 22. DETAILED DESCRIPTION

[0022] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0023] Embodiment 1: In order to solve the inadaptability of the existing device, the present invention provides a vertical penetrating double-shoulder friction stir welding device for the longitudinal seam of a tank, which can be applied to the vertical penetrating double-shoulder friction stir welding device for the longitudinal seam of a tank barrel section and a shell section, such as Figures 1 to 10 As shown, it includes a part tooling assembly 1, a back synchronous support system 2, and an external welding component 3. The part tooling assembly 1 is used to fix the welded part 7 and limit the movement of the welded part 7; the back synchronous support system 2 can support the welded part 7, and at the same time can realize the synchronous movement of the synchronous pad 9 and the external welding head 14; the external welding component 3 has a pressure claw system 15, and the pressure claw system 15 can press the welded part 7. The external welding head 14 and the synchronous pad 9 are respectively installed with a stirring tool 20 and a stationary lower shoulder pad 13, which can realize the vertical penetration double shoulder friction stir welding of the longitudinal seam of the tank.

[0024] like Figure 1 to Figure 4 As shown, the part tooling assembly 1 includes a tooling base 4, an inner welding tooling 5, and an outer welding tooling 6. The bottoms of the inner welding tooling 5 and the outer welding tooling 6 are both arranged on the tooling base 4. The tooling base 4 is mainly used for overall tooling support. The inner welding tooling 5 mainly cooperates with the back synchronous support system 2 to externally support the welded part 7 to ensure the flatness and roundness of the welding edge of the welded part 7 and prevent misalignment. The welded part 7 is arranged between the inner welding tooling 5 and the outer welding tooling 6. The outer welding tooling 6 is fixed and immovable. The outer welding tooling 6 cooperates with the inner welding tooling 5 to clamp the welded part 7 together.

[0025] Furthermore, the inner welding tool 5 and the outer welding tool 6 can be replaced according to the size of the part 7 to be welded, ensuring that the equipment can be applied to the longitudinal seam penetration double-shoulder friction stir welding of shell segments and cylinder segments of various diameters.

[0026] like Figure 5 , Figure 6 As shown, the back synchronous support system 2 includes an internal support system 8, a synchronous pad 9, an internal transmission mechanism 10, an internal column 11, and an internal base 12. The internal column 11 is arranged on the internal base 12, and the internal support system 8 is arranged on the internal column 11. The internal support system 8 includes a plurality of hydraulic cylinders, which are installed on the internal column 11. The main function is to make the internal column 11 and the internal welding tool 5 form a whole, thereby improving the rigidity of the two. The synchronous pad 9 is installed with a static lower shoulder pad 13, which mainly supports the back of the welding side of the welded part 7 during welding. The internal transmission mechanism 10 is arranged on the internal column 11, and the internal transmission mechanism 10 can make the synchronous pad 9 realize synchronous movement with the external welding head 14; the internal base 12 is mainly used for overall support.

[0027] like Figure 7 , Figure 8As shown, the external welding assembly 3 includes an external welding head 14, a pressure claw system 15, a top tensioning system 16, an external welding transmission system 17, an external welding column 18, and an external welding base 19. A stirring tool 20 is installed on the external welding head 14. The external welding head 14 uses a mechanical external spindle motor, which improves the welding capacity and stability while also improving the maintenance economy. The pressure claw system 15 is arranged on the side of the external welding column 18 and directly faces the welded part 7, and is mainly used to press the welded part 7; the top tensioning system 16 is driven by the winch at the top of the external welding column 18 to realize the rotation of the tensioning arm. After it is in place, the hydraulic drive mechanism at the top of the internal column 11 pushes the shaft pin to lock it. The top tensioning system 16 is used to connect the internal column 11 and the external welding column 18, improve the top rigidity, and reduce the opening amount of the welded part 7 when it is welded to the upper end. It should be noted that both the inner column 11 and the outer welding column 18 are equipped with a transmission system, and both belong to the same control system, which can realize the synchronous movement of the outer welding head 14 and the synchronous pad 9.

[0028] Specifically, the stationary lower shoulder pad 13 has a waist-shaped hole 131, which is used to hold the filling material 21. The length of the stirring needle of the stirring tool 20 is 1 mm larger than the thickness of the welded part 7; the diameter of the stationary lower shoulder pad 13 is 6 mm larger than the diameter of the upper shoulder of the stirring tool 20, the length of the waist-shaped hole 131 of the stationary lower shoulder pad 13 is 8 mm larger than the diameter of the root of the stirring needle of the stirring tool 20, the width of the waist-shaped hole 131 of the stationary lower shoulder pad 13 is 4 mm larger than the diameter of the root of the stirring needle of the stirring tool 20, and the depth of the waist-shaped hole 131 of the stationary lower shoulder pad 13 is 1.5 mm larger than the difference between the thickness of the welded part 7 and the needle length of the stirring tool 20.

[0029] Furthermore, the length of the filling material 21 is 0.1-1 mm smaller than the length of the waist-shaped hole 131 of the stationary lower shaft shoulder pad 13, the width of the filling material 21 is 0.1-1 mm smaller than the width of the waist-shaped hole of the stationary lower shaft shoulder pad 13, and the thickness of the filling material 21 is 0-0.5 mm smaller than the depth of the waist-shaped hole of the stationary lower shaft shoulder pad 13, and is matched with the waist-shaped hole clearance of the stationary lower shaft shoulder pad 13. During positioning welding, it is only necessary to replace the stationary lower shaft shoulder pad 13 with a hole with a flat pad without a hole, which improves the flexibility of welding.

[0030] like Figure 8 As shown, the external welding head 14 is equipped with a laser ring scanning device 22. The laser ring scanning device 22 adopts a laser ring scanning type stir friction welding process detection system. The laser ranging sensor rotates around the stirring tool 20. The spatial three-dimensional coordinates of the monitoring point are obtained through the encoder in the servo motor and the height of the detection point. An algorithm for extracting parameters such as the inclination angle of the stirring tool 20, the shoulder pressure amount and the weld deviation during online detection of welding is designed.

[0031] Furthermore, the laser scanning device 22 adopts a multi-parameter detection system for weld posture of end motion detection to realize the synchronous detection of multiple parameters such as weld deviation, press-in amount, posture, etc., restore the three-dimensional morphology of the surface of the welded part 7 near the stirring tool 20, and adopt an adaptive PID controller based on reinforcement learning to realize adaptive tracking control of the welding process. At the same time, the laser scanning device 22 adopts a pressure detection elastic body, uses a strain gauge bridge to convert the strain signal into an electrical signal, and establishes a theoretical connection between the signal and the upsetting force, so as to detect and analyze the upsetting force information of the welding process and perform constant pressure adaptive control.

[0032] The present invention also provides a vertical double-shoulder friction stir welding method for a tank longitudinal seam, using a vertical penetrating double-shoulder friction stir welding device for a tank longitudinal seam, comprising the following steps: The first step is preliminary preparation: assemble the stirring tool 20 on the external welding head 14, fix the static lower shoulder pad 13 on the synchronous pad 9, observe whether the center of the stirring needle of the stirring tool 20 is placed 0 to 3 mm away from the center of the waist-shaped hole 131 of the static lower shoulder pad 13, start the transmission system, move the stirring tool 20 and the static lower shoulder pad 13 along the welding direction under no-load state, and observe whether the two are synchronized during the process; The second step is parts assembly: the welding edge of the welded part 7 is fused and positioned in sections to form a complete cylinder, and the welded part 7 is lifted between the inner welding fixture 5 and the outer welding fixture 6 with the help of a crane, and the welded part 7 is clamped with the fixture, and the top tensioning system 16 is started to tighten the inner column 11 and the outer welding column 18, and then the internal support system 8 is started to support the welded part 7 outward, and then the pressure claw system 15 is started to press the welded part 7 from the outside, and the assembly is completed at this time; The third step is positioning welding: after ensuring that the stirring tool 20 and the stationary lower shoulder pad 13 move synchronously, remove the stirring tool 20 and the stationary lower shoulder pad 13, replace the flat pad without holes and the positioning welding stirring tool (the needle length is selected to be 2-2.5 mm) for positioning welding, ensure that the welding part 7 to be welded is located at the center of the positioning welding stirring tool, and the surface of the flat pad is in close contact with the lower surface of the welded part 7, input the selected welding process parameters into the control system, and adjust the inclination angle of the positioning welding stirring tool, start the equipment for positioning welding, and the welding method is that the welded part 7 is fixed, and the positioning welding stirring tool and the flat pad move synchronously along the welding direction; The fourth step is formal welding: remove the positioning welding stirring tool and the flat pad, replace them with the stirring tool 20 and the stationary lower shoulder pad 13, and move them to the welding starting position. Change the welding process parameters in the control system of the equipment, and after centering again, start the stir friction welding equipment for formal welding. The welding method is that the welded part 7 is fixed, and the stirring tool 20 and the stationary lower shoulder pad 13 move synchronously along the welding direction. The pressing amount can be adjusted according to the actual situation during the process.

[0033] In practical applications, the inclination angle of the stirring tool 20 fixed on the external welding head 14 is preferably 2.5°. During the welding process, the part tooling assembly 1 and the welded part 7 are stationary, the stirring needle of the stirring tool 20 penetrates the welded part 7 and is inserted into the waist-shaped hole of the stationary lower shoulder pad 13, and the external welding head 14, the synchronous pad 9, the stirring tool 20, the stationary lower shoulder pad 13, and the filling material 21 move along the welding direction with the transmission system and always remain on the same axis until the welding is completed. The present invention can realize vertical penetrating double-shoulder stir friction welding, which can be applied to the longitudinal seam welding of the cylinder section and the shell section of the tank, eliminating the potential risk of incomplete welding and weak connection at the root of the weld.

[0034] Embodiment 2: This embodiment is a preferred example of Embodiment 1. This embodiment takes the welding of 10 mm thick 2219 aluminum alloy barrel section wall panels as an example, and uses a vertical penetrating double-shoulder friction stir welding device and corresponding tools to illustrate the steps of friction stir welding.

[0035] In this embodiment, the part tooling assembly 1 is suitable for a cylinder section with a diameter of 3350 mm. The welded part 7 is 4 identical 1 / 4 arc wall panels with dimensions of 2631 mm (arc length) × 1945 mm (height) × 10 mm (thickness); the upper shoulder diameter of the stirring tool 20 is 26 mm, and the stirring needle is a conical stirring needle with three sections and right-handed threads, with a needle length of 11 mm and a root diameter of 6 mm; the stationary lower shoulder pad 13 has a waist-shaped hole, the lower shoulder diameter is 32 mm, and the waist-shaped hole is located at the center of the stationary lower shoulder pad 13, with dimensions of 16 mm (length) × 10 mm (width) × 2.5 mm (depth); the filling material 21 is a waist-shaped block of 2219 aluminum alloy of the same material as the welded part 7, with dimensions of 15.5 mm (length) × 9.5 mm (width) × 2 mm (thickness), and is gap-matched with the waist-shaped hole of the stationary lower shoulder pad 13.

[0036] The principle of vertical through-type double-shoulder friction stir welding in this embodiment is as follows: 1. Preliminary preparation: Assemble the stirring tool 20 on the external welding head 14, fix the static lower shoulder pad 13 on the synchronous pad 9, observe whether the center of the stirring needle of the stirring tool 20 is placed 0 to 3 mm away from the center of the waist-shaped hole of the static lower shoulder pad 13, start the transmission system, move the stirring tool 20 and the static lower shoulder pad 13 along the welding direction under no-load state, and observe whether the two are synchronized during the process; 2. Parts assembly: The welding edge of the welded part 7 is fused and positioned in sections to form a complete cylinder. The welded part 7 is lifted between the inner welding fixture 5 and the outer welding fixture 6 with the help of a crane. The welded part 7 is clamped with the fixture. The top tensioning system 16 is started to tighten the inner column 11 and the outer welding column 18. Then the inner support system 8 is started to support the welded part 7 outwards. Then the pressure claw system 15 is started to press the welded part 7 from the outside. At this time, the assembly is completed; 3. Position welding: After ensuring that the stirring tool 20 and the stationary lower shoulder pad 13 move synchronously, remove the stirring tool 20 and the stationary lower shoulder pad 13, replace the flat pad without holes and the positioning welding stirring tool (the needle length is 2-2.5mm) for positioning welding, ensure that the welding part 7 to be welded is located at the center of the positioning welding stirring tool, and the surface of the flat pad is in close contact with the lower surface of the welded part 7, input the selected welding process parameters into the control system (the rotation speed is 600r / min, the welding speed is 200mm / min), and adjust the inclination angle of the positioning welding stirring tool (the inclination angle is 2.5°), start the equipment for positioning welding, and the welding method is that the welded part 7 is fixed, and the positioning welding stirring tool and the flat pad move synchronously along the welding direction; 4. Formal welding: remove the positioning welding stirring tool and the flat pad, replace them with the stirring tool 20 and the stationary lower shoulder pad 13, and move them to the welding starting position. Change the welding process parameters in the control system of the equipment (rotation speed is 500r / min, welding speed is 150mm / min, inclination angle is 2.5°), and after centering again, start the stir friction welding equipment for formal welding. The welding method is that the welded part 7 is fixed, and the stirring tool 20 and the stationary lower shoulder pad 13 move synchronously along the welding direction. The pressing amount can be adjusted according to the actual situation during the process.

[0037] In the description of the present application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0038] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A vertical penetration double-shoulder friction stir welding device for tank longitudinal seams, characterized in that: include: A parts and tooling assembly (1) for fixing the parts to be welded (7); A back synchronous support system (2) arranged inside the welded part (7) and provided with a synchronous pad (9) for supporting the welded part (7); The external welding assembly (3) comprises an external welding head (14) and a pressure claw system (15), wherein the pressure claw system (15) is capable of pressing the welded part (7), and a stirring tool (20) and a stationary lower shoulder pad (13) are respectively installed on the external welding head (14) and a synchronous pad (9), thereby realizing a vertical penetrating double-shoulder friction stir welding operation of a tank longitudinal seam.

2. The vertical penetration double-shoulder friction stir welding equipment for tank longitudinal seams according to claim 1 is characterized in that: The part tooling assembly (1) comprises a tooling base (4), an inner welding tooling (5), and an outer welding tooling (6); the bottoms of the inner welding tooling (5) and the outer welding tooling (6) are both arranged on the tooling base (4); the outer welding tooling (6) is arranged along the circumference of the inner welding tooling (5), and the welded part (7) is arranged between the inner welding tooling (5) and the outer welding tooling (6); the outer welding tooling (6) is fixed and cooperates with the inner welding tooling (5) to clamp the welded part (7).

3. The vertical penetration double-shoulder friction stir welding equipment for tank longitudinal seams according to claim 2 is characterized in that: The back synchronous support system (2) comprises an internal support system (8), a synchronous pad (9), an internal transmission mechanism (10), an internal column (11) and an internal base (12); The internal column (11) is arranged on the internal base (12), the internal support system (8) is configured on the internal column (11) so that the internal column (11) and the internal welding tool (5) form a whole, and the internal transmission mechanism (10) can drive the synchronous pad (9) to achieve synchronous movement with the external welding machine head (14).

4. The vertical penetration double-shoulder friction stir welding equipment for tank longitudinal seams according to claim 3 is characterized in that: The internal support system (8) comprises a plurality of hydraulic cylinders, wherein the plurality of hydraulic cylinders are mounted on an internal column (11), and the internal column (11) and the internal welding tool (5) are formed into a whole by the hydraulic cylinders.

5. The vertical penetration double-shoulder friction stir welding equipment for tank longitudinal seams according to claim 1 is characterized in that: The external welding assembly (3) comprises an external welding head (14), a pressure claw system (15), a top tensioning system (16), an external welding transmission system (17), an external welding column (18), and an external welding base (19); the external welding head (14) is arranged at the bottom of the external welding column (18) and is equipped with a stirring tool (20); The pressure claw system (15) is arranged on the side of the outer welding column (18) and faces the welded part (7); the two ends of the top tensioning system (16) are respectively connected to the inner column (11) and the outer welding column (18) and are capable of tensioning the inner column (11) and the outer welding column (18).

6. The vertical penetration double-shoulder friction stir welding equipment for tank longitudinal seams according to claim 5, characterized in that: The external welding machine head (14) adopts a mechanical external spindle motor; The top tensioning system (16) is driven by a winch at the top of the externally welded column (18) to achieve rotational movement of the tensioning arm.

7. The vertical penetration double-shoulder friction stir welding equipment for tank longitudinal seams according to claim 5, characterized in that: The inner column (11) and the outer welding column (18) are both equipped with a transmission system, and the two transmission systems belong to the same control system, which can achieve synchronous movement of the outer welding machine head (14) and the synchronous pad (9).

8. The vertical penetration double-shoulder friction stir welding equipment for tank longitudinal seams according to claim 5, characterized in that: The external welding machine head (14) is provided with a laser circular scanning device (22). The laser circular scanning device (22) adopts a laser circular scanning type stir friction welding process detection system, including a laser distance measuring sensor. The laser distance measuring sensor can rotate around the stirring tool (20), obtain the spatial three-dimensional coordinates of the monitoring point through the encoder in the servo motor and the height of the detection point, and can design a parameter extraction algorithm for online detection of the inclination angle, shoulder pressing amount and weld deviation of the stirring tool (20) during the welding process.

9. The vertical penetration double-shoulder friction stir welding equipment for tank longitudinal seams according to claim 8, characterized in that: The laser ring scanning device (22) adopts a pressure detection elastic body and utilizes a strain gauge bridge to convert a strain signal into an electrical signal, thereby establishing a theoretical connection between the signal and the upsetting force, so as to detect and analyze the upsetting force information during the welding process and to perform constant pressure adaptive control.

10. A vertical penetration double-shoulder friction stir welding method for tank longitudinal seams, characterized in that: The steps include: S1: Preliminary preparation: Assemble the stirring tool (20) on the external welding machine head (14), fix the stationary lower shoulder pad (13) on the synchronous pad (9), observe whether the center of the stirring needle of the stirring tool (20) is placed 0 to 3 mm away from the center of the waist-shaped hole of the stationary lower shoulder pad (13), start the transmission system, and move the stirring tool (20) and the stationary lower shoulder pad (13) along the welding direction in a no-load state, and observe whether the two are synchronized during the process; S2: Parts assembly: The welding edge of the welded part (7) is welded and positioned in sections to form a complete cylinder, the welded part (7) is assembled between the inner welding fixture (5) and the outer welding fixture (6) and the welded part (7) is clamped, the top tensioning system (16) is started to tighten the inner column (11) and the outer welding column (18), then the internal support system (8) is started to support the welded part (7) outward, and then the pressure claw system (15) is started to press the welded part (7) from the outside, and the assembly is completed at this time; S3: Position welding: After ensuring that the stirring tool (20) and the stationary lower shoulder pad (13) move synchronously, the stirring tool (20) and the stationary lower shoulder pad (13) are removed, and a flat pad without holes is replaced to perform position welding with the positioning welding stirring tool, ensuring that the welding point of the welded part (7) is located at the center of the positioning welding stirring tool, and the surface of the flat pad is in close contact with the lower surface of the welded part (7), the selected welding process parameters are input into the control system, and the inclination angle of the positioning welding stirring tool is adjusted, and the equipment is started to perform position welding, and the welding method is that the welded part (7) is fixed and the positioning welding stirring tool and the flat pad move synchronously along the welding direction; S4: Formal welding: Remove the positioning welding stirring tool and the flat pad, replace them with the stirring tool (20) and the stationary lower shoulder pad (13), and move them to the welding starting position. Change the welding process parameters in the control system of the equipment. After centering again, start the stir friction welding equipment for formal welding. The welding method is that the welded part (7) is fixed, and the stirring tool (20) and the stationary lower shoulder pad (13) move synchronously along the welding direction. During the process, the pressing amount can be adjusted according to the actual situation.

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