Simple workpiece clamping device for friction stir welding of T-shaped joint

Abstract

The invention discloses a simple workpiece clamping device for friction stir welding of a T-shaped joint, which is used for preparing the T-shaped friction stir welding joint and comprises a T-shaped joint clamp and a workpiece to be welded. The T-shaped connector clamp is composed of a clamp body (1), two pressing plates (2), two clamping plates (3), wing plate positioning screws (4) and web plate positioning screws (5). Four clamping ends (9) are arranged on the periphery of the clamp body and used for fixing the clamp. A sealing groove (10) is machined in the top of the clamp body and used for containing a wing plate (6), and horizontal positioning of the wing plate is achieved through a pressing plate (2) and a wing plate positioning screw (5). An open groove (11) is machined in the clamp body, and the web (7) is vertically positioned through the clamping plate (3) and the web positioning screw (6). The device is simple in structure, convenient to install and operate, low in manufacturing cost and capable of being customized in batches according to different requirements, firm positioning of the wing plate and the web plate can be achieved at the same time, the stability of friction stir welding of the T-shaped connector is improved, and the strength of the welding connector and the welding quality are improved.

Description

Technical Field

[0001] The invention relates to the field of metal processing, in particular to a simple friction stir welding T-joint clamping device. Background Art

[0002] Since the birth of the friction stir welding method in 1991, this technology has attracted the attention of scientific research institutions in various countries for its characteristics of small welding deformation, small residual stress, high quality of welded joints, green and environmental protection, and was soon used in the aerospace field. Since the workpiece is continuously subjected to severe friction, upsetting force and plastic deformation force during the welding process, ensuring that the welded workpiece is firmly clamped is the key to obtaining high-quality welds. For butt welding and lap welding, clamping is easy, and general fixtures can meet the needs. The aerospace field often involves the welding of T-shaped structural parts. For T-shaped weldments, there are many connection interfaces, including horizontal interfaces, vertical interfaces, 45° angle interfaces, and horizontal plus vertical interfaces. The degrees of freedom in all directions must be restricted. Therefore, special friction stir welding fixtures are often required.

[0003] Prior art 1 invented a laser-assisted friction stir welding device for thin plate T-joints. The device has a simple design and is conducive to improving weld quality and welding efficiency (a laser-assisted friction stir welding device and method for thin plate T-joints, application number: 201510476776.5). However, the invention is mainly aimed at heat-source-assisted friction stir welding, while the welding force during the general T-joint friction stir welding process is much greater, and the fixing effect of the device is limited; in addition, the device is also difficult to perform friction stir welding of thick plates.

[0004] Prior art 2 invented a T-joint friction stir welding fixture, which is flexible and can adjust the positioning height of the web according to different needs (a T-joint friction stir welding fixture, application number: 201620455367.7). However, the device has a complex structure, high manufacturing cost, difficult clamping, low welding efficiency, and is difficult to mass produce.

[0005] Therefore, designing a T-joint fixture that can not only achieve reliable fixation of the T-shaped workpiece to the greatest extent, but also minimize costs and can be installed simply and quickly is a task with great engineering and research significance. Summary of the invention

[0006] In view of the problems existing in the current friction stir welding T-joint clamp, the purpose of the present invention is to provide a simple friction stir welding T-joint clamping device to avoid the collision between the stirring needle and the clamping plate, which not only realizes the firm clamping of the workpiece under low cost conditions, but also improves the stability of welding.

[0007] The present invention is achieved through the following technical solutions:

[0008] A simple friction stir welding T-joint clamping device, the T-joint clamp comprising a clamp body (1), two pressing plates (2), two clamping plates (3), wing plate positioning screws (4), and web plate positioning screws (5); four supporting ends (9) are arranged on the periphery of the clamp body for fixing the clamp; a closed groove (10) is processed on the top of the clamp body for placing the wing plate (6) and horizontal positioning of the wing plate is achieved through the pressing plate (2) and the wing plate positioning screws (5); an open groove (11) is processed on the clamp body and vertical positioning of the web plate (7) is achieved through the clamping plates (3) and the web plate positioning screws (6);

[0009] The friction stir welding T-joint clamping device has threaded holes on the top and sides of the clamp body, four threaded through holes (13) for web positioning, and the matching studs (5) are M12; eight threaded blind holes (12) for wing plate longitudinal positioning, three threaded through holes (12-1) for wing plate transverse positioning, and the matching studs (4) are M6 in size;

[0010] The friction stir welding T-joint clamping device has a closed groove (10) for placing the wing plate with a size of 180 mm×100 mm×3 mm, and an open groove (10) for placing the web plate with a size of 180 mm×60 mm×60 mm; in addition, the sizes of the closed groove and the open groove can be designed according to actual welding requirements;

[0011] The friction stir welding T-joint clamping device tightens the pressure plate through the wing plate positioning screws (4) to limit the vertical freedom of the wing plate, and the wing plate positioning screws (4) on the side are used for further positioning in the horizontal direction;

[0012] The friction stir welding T-joint clamping device has 8 through holes processed on the pressure plate, and the positions of the through holes match the threaded blind holes (12) on both sides of the closed groove;

[0013] The friction stir welding T-joint clamping device has an opening groove, a clamping plate and a web plate that are kept consistent in depth, and the clamping plate is fixed by tightening the web plate positioning stud (5); arc chamfers (15) are processed on the two clamping plates to prevent the stirring head (8) from colliding with the clamping plate, and the arc chamfers can be replaced with edge chamfers or round chamfers of different sizes according to different needs;

[0014] When the friction stir welding T-joint clamping device is used for welding, the following steps are specifically included:

[0015] (1) placing the clamping device body on a welding workbench and clamping the clamping end (9) with a common clamp to ensure that the clamp body is securely fixed;

[0016] (2) Fix the web plate by clamping the web plate with two chamfered clamping plates and placing them in the open groove, while pressing against the end of the open groove (14), and then tightening the four studs (5) to effectively fix the web plate;

[0017] (3) Fixing the wing plate: Place the wing plate with a thickness slightly greater than the depth of the closed groove (10) in the groove, and close the ends. Then place two pressure plates and tighten the eight top studs (4), and then lightly tighten the three side studs (4) to effectively fix the wing plate.

[0018] (4) Determine the welding parameters, set the welding procedure, and start welding; after the test, unscrew all screws and remove the workpiece safely; Beneficial effects:

[0019] 1. The advantages of the present invention are simple structure and low manufacturing difficulty. It can be completed in an ordinary small workshop. It is not only suitable for T-type welding experiments in the laboratory, but also can batch manufacture multiple fixtures to facilitate batch production of stir friction welding T-type joint products. Moreover, it has low cost and simple manual operation during the experiment.

[0020] 2. It has a wide range of applications and a long service life. Relevant standards can be formulated according to actual production needs. The welding of T-shaped structural parts of different standards can be met by modifying the sizes of closed grooves and open grooves. At the same time, the manufacturing materials can be changed according to the performance differences of the welded materials.

[0021] 3. Currently, there are few public inventions about the T-joint clamping device for friction stir welding. Although there are some excellent T-clamp inventions, their structural complexity not only increases the economic cost of manufacturing, but also increases the manufacturing time cost, making it difficult to meet actual production needs. The present invention only needs to use a CNC milling machine to process the cubic material into a clamping end, a closed groove, an open groove, a through hole, and a blind hole according to the drawing, and then tap the thread to complete the manufacture of the clamp body. The clamping and disassembly during the experiment are simple, which greatly improves the experimental efficiency and welding stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the structure of the present invention;

[0023] Figure 2 It is a structural schematic diagram (disassembly diagram) of the present invention;

[0024] Figure 3 is a schematic diagram of the clamp body of the present invention;

[0025] Figure 4 is a schematic diagram of a splint of the present invention;

[0026] Figure 5 The surface and fillet weld morphology of the Mg / Al dissimilar metal friction stir welding T-joint after welding in Example 1 of the present invention;

[0027] Figure 6 The surface and fillet weld morphology of the 2024 / 5083 dissimilar aluminum alloy friction stir welding T-joint after welding in Example 2 of the present invention;

[0028] In the figure, 1-clamp body, 2-pressing plate, 3-clamping plate, 4-wing plate positioning screw, 5-web plate positioning screw, 6-wing plate, 7-web plate, 8-stirring head, 9-clamping end, 10-closed groove, 11-open groove, 12-wing plate positioning screw hole, 13-web plate positioning screw hole, 14-open groove end, 15-arc chamfer, DETAILED DESCRIPTION

[0029] Example 1

[0030] In this embodiment, the wing plate is made of AZ31 magnesium alloy, the web plate is made of 2024 aluminum alloy, and the specific experimental steps of using the above-mentioned welding T-joint clamping device are as follows:

[0031] (1) The clamping device body is placed on a welding workbench, and the clamping end (9) is clamped with a common clamp to ensure that the clamp body is reliably fixed; the welding equipment used is a friction stir welding machine modified from a Gaoteng CNC milling machine (XK7104), the workbench size is 1000×600mm, the clamp body is made of 45 steel, and its bottom size is 210×200mm;

[0032] (2) Fix the web plate. Use two chamfered clamping plates to clamp the web plate and place it in the open groove, and at the same time, close to the end of the open groove (14). The size of the open groove is 200×50×60 (height) mm. Then tighten four M12 studs (5) to achieve effective fixation of the web plate. The web plate used is a 2024 aluminum alloy plate with a size of 180×3 (plate thickness)×60 (height) mm. The size of the clamping plate is 200×20×60 (height) mm. The clamping plate is made of 45 steel and has a 2 mm arc chamfer.

[0033] (3) Fixing the wing plate: Place the wing plate with a thickness slightly greater than the depth of the closed groove (10) in the groove, and at the same time, close the ends. Then place two pressing plates and tighten the eight top M6 studs (4). Then, lightly tighten the three side M6 studs (4) to achieve effective fixing of the wing plate. The size of the closed groove is 200.5×100.5×3 (height) mm, and the size of the wing plate is 200×100×2.9 (height) mm. This size design is conducive to the effective matching of the groove and the wing plate.

[0034] (4) Determine the welding parameters, set the welding procedure, and start welding. After the test, unscrew all screws and remove the workpiece safely. The weld surface and fillet weld morphology are as follows: Figure 5 shown.

[0035] Example 2

[0036] In this embodiment, the wing plate is made of 2024 aluminum alloy, the web plate is made of 5083 aluminum alloy, and the experimental process is the same as that of Example 1. The obtained weld surface and cross-sectional morphology are as follows: Figure 6 shown.

Claims

1. A simple friction stir welding T-joint clamping device, comprising a T-joint clamp and a workpiece to be welded, characterized in that: The T-joint clamp comprises a clamp body (1), two pressure plates (2), two clamping plates (3), wing plate positioning screws (4), and web plate positioning screws (5); four supporting ends (9) are provided on the periphery of the clamp body for fixing the clamp; a closed groove (10) is processed on the top of the clamp body for placing the wing plate (6) and horizontal positioning of the wing plate is achieved through the pressure plate (2) and the wing plate positioning screws (5); an open groove (11) is processed on the clamp body and vertical positioning of the web plate (7) is achieved through the clamping plates (3) and the web plate positioning screws (6); 2. The friction stir welding T-joint clamping device according to claim 1, characterized in that: The top and sides of the fixture body are machined with threaded holes, four threaded through holes (13) for web positioning, and the matching studs (5) are M12; eight threaded blind holes (12) for wing plate longitudinal positioning, and three threaded through holes (12-1) for wing plate transverse positioning, and the matching studs (4) are M6 in size; 3. The friction stir welding T-joint clamping device according to claim 1, characterized in that: The size of the closed groove (10) for placing the wing plate is 180 mm × 100 mm × 3 mm, and the size of the open groove (10) for placing the web plate is 180 mm × 60 mm × 60 mm; in addition, the size of the closed groove and the open groove can be designed according to actual welding requirements; 4. The friction stir welding T-joint clamping device according to claim 1, characterized in that: The pressure plate is tightened by the wing plate positioning screws (4) to limit the vertical freedom of the wing plate, and the wing plate positioning screws (4) on the side are used for further positioning in the horizontal direction; 5. The friction stir welding T-joint clamping device according to claim 1, characterized in that: The pressing plate is provided with 8 through holes, the positions of which match the threaded blind holes (12) on both sides of the closed groove; 6. The friction stir welding T-joint clamping device according to claim 1, characterized in that: The depths of the opening groove, the clamping plate and the web are kept consistent, and the clamping plate is fixed by tightening the web positioning stud (5); arc chamfers (15) are processed on the two clamping plates to prevent the stirring head (8) from colliding with the clamping plate, and the size of the arc chamfer is 1-2 mm, and the arc chamfer can also be replaced according to different needs; The clamping device is made of 45 steel, and the welded materials are aluminum alloy and magnesium alloy; During the experiment, the clamping device must ensure that the welding direction is directed toward the end (14) of the open groove.

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