Stirring tool and method for through type friction stir welding

Abstract

The invention relates to the technical field of friction stir welding, and discloses a stirring tool and method for penetrating type friction stir welding, the stirring tool comprises a switching cutter handle and a stirring cutter, the stirring cutter comprises an upper clamping body arranged on the upper portion, a lower clamping body arranged on the lower portion and an outer sleeve arranged outside the upper clamping body and the lower clamping body in a sleeving mode, the upper part of the lower clamping body is connected with the upper clamping body, a stirring rod is arranged in the upper clamping body and the lower clamping body in a penetrating manner, and the upper part of the upper clamping body is connected with the switching cutter handle; at least one group of cutting and rolling cutters are uniformly distributed at the bottom of the outer sleeve, each cutting and rolling cutter comprises an upper cutting surface, a lower cutting surface and a rolling surface parallel to a workpiece to be welded, the rolling surfaces are arranged on the bottom surfaces of the cutting and rolling cutters, the intersecting lines of the upper cutting surfaces and the lower cutting surfaces are main cutting edges, the upper cutting surfaces are arc surfaces, and the lower cutting surfaces are arc surfaces. And the height difference between the main cutting edge and the rolling surface is h. The flash can be cut at a fixed height along with welding, so that the surface flatness of a workpiece is remarkably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of friction stir welding and relates to a stirring tool and a method for through-type friction stir welding. Background Art

[0002] Friction stir welding (FSW) is an efficient and green solid-phase welding technology with advantages such as excellent weld joint mechanical properties, relatively low residual stress, and reduced deformation of the welded workpiece. It is widely used in aerospace, new energy storage, shipbuilding, rail transit, and other fields. Through-hole eddy current FSW is a modified FSW process based on plastic vortexing. This process replaces the traditional FSW stir tip with a homogeneous rod (low-value, consumable material), addressing the wear and breakage issues of traditional stir tips when welding high-melting-point materials. Furthermore, through-hole eddy current FSW can significantly increase the weldable thickness, showing promising application prospects. To prevent plastic material overflow and reduce defects such as porosity and cracks in the joint, through-hole eddy current FSW and traditional FSW typically require the shoulder of the stirring tool to be pressed into the workpiece to a certain depth. This provides forging pressure and increases the degree of plasticization. Due to factors such as the depth of the stirring tool shoulder and excessive heat input, the welding process may risk weld flash and surface oxidation, which can affect the workpiece surface quality and lead to weld brittleness. Chinese invention patent CN110814509A discloses a flash-free and thinned shoulder-free friction stir welding tool and method. This tool utilizes a shoulder-free stirring pin and a matching pressure plate to achieve flash-free friction stir welding. However, pre-welding tool assembly is time-consuming, the weld trajectory is inflexible, and the device lacks inert gas shielding. Chinese invention patent CN112548316A discloses a weld deburring and quality inspection device that utilizes a pneumatic milling cutter and a laser rangefinder to remove weld burrs and inspect weld surface height. However, this method mills the burrs after welding, reducing welding efficiency. Summary of the Invention

[0003] In response to the shortcomings of the existing technology, the present invention provides a stirring tool and method for through-type stir friction welding, which can cut the flash at a fixed height during welding and roll the plastic protrusions on the workpiece surface, thereby significantly improving the surface flatness of the workpiece, and can improve the residual stress of the weld during the rolling process.

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

[0005] In the first aspect, the present invention proposes a stirring tool for through-type stir friction welding, including an adapter handle and a stirring tool, the stirring tool including an upper clamping body arranged at the upper part, a lower clamping body arranged at the lower part, and an outer sleeve arranged on the outside of the upper clamping body and the lower clamping body, the upper part of the lower clamping body is connected to the upper clamping body, the upper clamping body and the lower clamping body are provided with a stirring rod, and the upper part of the upper clamping body is connected to the adapter handle; at least one group of cutting and rolling tools are evenly distributed on the bottom of the outer sleeve, and the cutting and rolling tools include a tool top surface, an upper cutting surface, a lower cutting surface and a tool parallel to the workpiece to be welded. The rolling surface is arranged on the bottom surface of the cutting rolling tool, the intersection of the upper cutting surface and the lower cutting surface is the main cutting edge, the upper cutting surface is an arc surface, and a rolling transition arc surface is provided between the lower cutting surface and the rolling surface. The height difference between the main cutting edge and the rolling surface is △h, △h is the cutting height, and the setting of the cutting rolling tool can timely remove the flash formed in the welding process at a certain height; at the same time, the convex surface of the weld and the shaped flash below the main cutting edge will be rolled in sequence by the rolling transition arc surface and the rolling surface, thereby significantly improving the surface flatness of the workpiece, and the residual stress of the weld can be improved during the rolling process.

[0006] Preferably, three groups of cutting and rolling tools are provided, namely a first cutting and rolling tool, a second cutting and rolling tool and a third cutting and rolling tool; the cutting and rolling tools are tools made of cemented carbide.

[0007] In combination with the first aspect, further, the lower clamping body is made of cemented carbide, and the lower clamping body acts as the shoulder of a traditional stirring head; the lower clamping body is a cylindrical structure and a rod through hole is provided in the core; the rod through hole is used to clamp a homogeneous stirring rod or a stirring head, and the homogeneous stirring rod is made of the same material as the base material of the workpiece to be welded.

[0008] The cam is secured to the upper end of the support frame and is secured to the lower portion of the support frame by a spring. The pressure-adjusting nut can be used to control the pressing force of the pressure-adjusting spring on the floating outer sleeve, thereby adjusting the pressure of the rolling surface of the cutting and rolling tool relative to the workpiece surface; the floating outer sleeve can float axially flexibly along the stirring spindle, which can reduce the impact of the cutting and rolling tool on the spindle during welding.

[0009] In combination with the first aspect, further, the core of the adapter tool holder is provided with a tool holder core cooling channel, and the adapter tool holder also includes a rotary interface for introducing coolant into the core of the adapter tool holder; the top of the tool holder core cooling channel is a rotary interface, and the rotary interface is also used to dock with the rotary joint on the stir friction welding machine; the core of the upper clamping body is provided with an upper clamping body core cooling channel; the core of the lower clamping body is provided with a rod through hole, and the core of the stirring rod is provided with a through hole; the tool holder core cooling channel, the upper clamping body core cooling channel, the rod through hole and the through hole of the stirring rod core are all interconnected, forming a cooling circuit during welding.

[0010] In combination with the first aspect, the outer sleeve further includes an outer sleeve air inlet, an outer sleeve air duct, and an air blowing hole; the air blowing hole is disposed at the bottom of the outer sleeve and above the upper cutting surface of the cutting and rolling tool; the outer sleeve air duct is disposed within the outer sleeve for connecting the air blowing hole and the outer sleeve air inlet; the outer sleeve air inlet is disposed on the outer wall of the outer sleeve for introducing positive pressure inert gas. The provision of the air blowing hole can provide continuous inert gas protection and a pulsed chip blowing gas source for welding.

[0011] Furthermore, there is at least one blowing hole, which is arranged corresponding to the cutting and rolling tool. Preferably, there are three blowing holes, namely the first blowing hole, the second blowing hole and the third blowing hole, which are arranged corresponding to the first cutting and rolling tool, the second cutting and rolling tool and the third cutting and rolling tool.

[0012] Furthermore, the upper clamping body also includes a tool clamping end provided at the top, and the adapter tool holder is provided with an upper clamping body fixing threaded hole, through which the upper clamping body and the adapter tool holder are fixed together; the upper clamping body also includes a rod clamping fixing threaded hole, and the top of the stirring rod is provided with a rod fixing section that matches the rod clamping fixing threaded hole. The stirring rod is fixedly connected to the upper clamping body through the combination of the rod clamping fixing threaded hole, the rod fixing section, and the bolt. The top of the stirring rod is also provided with a rod sealing ring that seals with the upper clamping body to prevent coolant from leaking from the cooling circuit.

[0013] In combination with the first aspect, further, the lower part of the adapter tool handle is a cylindrical surface, and the stirring tool also includes a rotating jacket module that is integrally mounted on the lower part of the adapter tool handle; the rotating jacket module is used to introduce inert gas into the stirring tool; the rotating jacket module includes a jacket air inlet, and the adapter tool handle is sequentially provided with a tool handle air inlet, a tool handle gas channel and a tool handle air outlet that are communicated with the jacket air inlet, and the tool handle gas channel is used to connect the tool handle air inlet and the tool handle air outlet; the tool handle air outlet is located below the rotating jacket module; the tool handle air outlet is connected to the outer sleeve air inlet through an air pipe; the jacket air inlet is connected to the gas source.

[0014] In combination with the first aspect, further, the rotating jacket module includes a jacket bracket, a jacket shell and a jacket bracket round rod, the jacket bracket is fixedly connected to the jacket shell, and the jacket bracket round rod is fixedly connected to the Z-axis drive module of the stir friction welding machine, which is used to fix the rotating jacket module as a whole on the Z-axis drive module, so that the adapter tool holder can rotate inside the rotating jacket module; the interior of the jacket shell is provided with a first jacket bearing, a first jacket spacer, a first jacket dynamic seal, a second jacket dynamic seal, a second jacket spacer and a second jacket bearing from top to bottom; a rotating jacket cavity is provided between the first jacket dynamic seal and the second jacket dynamic seal, and the tool holder air inlet and the jacket air inlet are respectively located in the rotating jacket cavity.

[0015] In combination with the first aspect, further, the jacket bracket includes a jacket upper end cover connected to the upper part of the jacket shell and a jacket lower end cover connected to the lower part of the jacket shell. Preferably, the jacket bracket and the jacket shell are fixedly connected by bolts.

[0016] In combination with the first aspect, further, the gas source includes a first gas source and a second gas source, the gas pressure of the first gas source is lower than the gas pressure of the second gas source; the jacket gas inlet is connected to the first gas source and the second gas source respectively.

[0017] Preferably, the first gas source is nitrogen at 0.05-0.1 Mpa; the second gas source includes a high-pressure storage tank and a pulse solenoid valve connected in sequence through a gas pipe, and the high-pressure storage tank is used to provide high-pressure argon or high-pressure nitrogen.

[0018] In combination with the first aspect, the stirring tool of the present invention further includes a welding inert gas protective cover arranged on the welding platform, which is used to place the stirring tool and the workpiece to be welded in an inert gas micro-positive pressure environment; the welding platform includes a welding fixture; the outside of the welding inert gas protective cover is a rectangular protective cover shell, and the side of the protective cover shell is provided with an inert gas exhaust hole. The setting of the inert gas exhaust hole enables the welding inert gas protective cover to maintain a constant micro-positive pressure; the bottom of the protective cover shell is provided with a protective cover shell fixing hole for fixing the welding inert gas protective cover on the welding fixture; the protective cover shell is also provided with a welding movable plate, a movable plate pressing block and a movable plate guide block, and the welding movable plate is provided with a movable plate tool handle through hole for the lower part of the adapter tool handle to pass through; the welding movable plate is also provided with a movable plate driving hole for inserting the jacket bracket round rod, and the matching setting of the jacket bracket round rod and the movable plate driving hole enables the welding movable plate to follow the stirring tool to move in the X axis during welding.

[0019] In combination with the first aspect, the stirring tool of the present invention further includes a lower rotating support for supporting the softened material during the welding process, the lower rotating support is arranged at the lower part of the welding platform, and the welding platform is fixed on the X-axis drive module of the stir friction welding machine; the lower rotating support includes a supporting beam, a reflow shell, a lower rotating body and an upper rotating body; the supporting beam is fixed to the frame of the stir friction welding machine through its own column; the reflow shell is fixed on the supporting beam, and a cooling reflow port is provided at the bottom of the reflow shell; the lower rotating body is sequentially provided with radial supports from top to bottom Bearings and axial support bearings, the top surface of the return shell is fixed with an axial bearing base and a radial bearing bracket, and the outer rings of the axial support bearing and the radial support bearing are fixed respectively; the upper rotating body is fixed on the upper part of the lower rotating body, and the upper part of the upper rotating body is provided with a support gasket; the support gasket is provided with a gasket through-hole for passing the stirring rod; the upper rotating body and the lower rotating body are both provided with a through-type core channel for passing the coolant; the axial bearing base is provided with a through-hole for installing the return oil seal; the lower part of the lower rotating body passes through the inner ring of the return oil seal.

[0020] Preferably, the support gasket is made of hard alloy.

[0021] In a second aspect, the present invention provides a method for through-type friction stir welding, using the above-mentioned stirring tool for through-type friction stir welding, comprising the following steps:

[0022] S1: After grinding, cleaning and pre-treatment, the workpiece to be welded is clamped on the welding platform, and the pressure regulating nut is loosened and tightened to adjust the pressure of the pressure regulating spring on the outer sleeve to the predetermined value;

[0023] S2: Control the rolling surface of the cutting rolling tool to contact the surface of the workpiece to be welded, and the blowing hole starts to provide low-pressure argon gas.

[0024] S3: The stirring tool starts to rotate and press down as a whole, and the cutting and rolling tool moves upward synchronously with the outer sleeve. The rolling surface of the cutting and rolling tool is pressed against the surface of the workpiece to be welded with a certain pressure;

[0025] S4: After the lower clamping body rotates and presses into the workpiece to be welded to a certain depth, it keeps rotating in place;

[0026] S5: The stirring tool starts to weld along the set weld path according to the set program;

[0027] S6: The pulse solenoid valve opens periodically to provide a pulse debris purge gas source of high-pressure argon gas to the blowing hole;

[0028] S7: Complete the welding task.

[0029] Compared with the prior art, the present invention provides a device and method for strengthening the heat-affected zone of friction stir welding with extrusion during welding, which has the following beneficial effects:

[0030] (1) The height difference between the main cutting edge and the workpiece surface of the cutting and rolling tool of the present invention is Δh, which can timely remove the flash formed during the welding process and the fixed height. At the same time, the convex surface of the weld and the shaped flash below the main cutting edge will be rolled by the rolling transition arc surface and the rolling surface in sequence, thereby significantly improving the surface flatness of the workpiece and reducing the residual stress of the weld during the rolling process.

[0031] (2) The present invention can control the pressing force of the pressure-adjusting spring on the floating outer sleeve through the pressure-adjusting nut, thereby adjusting the pressure of the rolling surface of the cutting and rolling tool relative to the workpiece surface; the floating outer sleeve can float axially and flexibly along the stirring spindle, which can reduce the impact of the cutting and rolling tool on the spindle during welding.

[0032] (3) The floating outer sleeve of the present invention is provided with a blow hole above the upper cutting surface of the cutting and rolling tool, which directly introduces low-pressure inert gas argon into the welding and cutting areas, providing continuous inert gas protection for the weld from the source. At the same time, a high-pressure storage tank and a pulse solenoid valve periodically provide a pulse of high-pressure argon gas to the blow hole, thereby purging debris from the cutting and rolling tool surface and the weld area with positive pressure gas.

[0033] (4) The core of the stirring tool of the present invention is provided with a coolant channel, which is not only suitable for through-type homogeneous eddy current stir friction welding, but also can be adapted to traditional stirring heads.

[0034] (5) The present invention can simultaneously realize four functions during the welding process: cutting and chip removal, rolling and leveling, inert gas protection, and positive pressure purging. It is applicable to through-type friction stir welding and conventional friction stir welding, and has the significant advantages of simple and reliable structure and high welding efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The three-dimensional structure of the friction stir welding machine equipped with the stirring tool of the present invention is shown in FIG. Figure 1 ( Figure 1 The inert gas protective cover for welding is not shown);

[0036] Figure 2 for Figure 1 Schematic diagram of the enlarged structure of the partial view A in the middle ( Figure 2 The inert gas protective cover for welding is not shown);

[0037] Figure 3 This is a schematic diagram of the assembly of the adapter handle, stirring tool, and lower rotating support in the present invention;

[0038] Figure 4 for Figure 3 Schematic diagram of the cross-sectional structure;

[0039] Figure 5 for Figure 4 A schematic diagram of the enlarged structure of the partial view B';

[0040] Figure 6 for Figure 4 A schematic diagram of the enlarged structure of the partial view C';

[0041] Figure 7 Schematic diagram of the three-dimensional structure of the stirring tool in Example 1;

[0042] Figure 8 for Figure 7 Schematic diagram of the cross-sectional structure;

[0043] Figure 9 Schematic diagram of the three-dimensional perspective structure of the outer sleeve in the present invention;

[0044] Figure 10 This is a schematic diagram of the main structure of the outer sleeve in the present invention;

[0045] Figure 11 for Figure 10 Schematic diagram of the cross-sectional structure of the middle edge DD;

[0046] Figure 12 It is a schematic structural diagram of the cutting and rolling tool in the present invention;

[0047] Figure 13 for Figure 12 Schematic diagram of the cross-sectional structure;

[0048] Figure 14 Schematic diagram of the structure of the welding inert gas protective cover in the present invention;

[0049] Figure 15 Schematic diagram of the gas path of the stirring tool in Example 1;

[0050] Figure 16 Schematic diagram of the process of using the stirring tool of the present invention for through-type friction stir welding, wherein Figure 16 a is the initial preparation stage, Figure 16 b is the rotation and downward pressure stage; Figure 16 c is the chip removal and rolling stage; Figure 16 d is Figure 16 c is an enlarged structural diagram of the local view E;

[0051] Figure 17 Schematic diagram of the process of using the stirring tool of the present invention for conventional friction stir welding, wherein Figure 17 a is the initial preparation stage, Figure 17 b is the rotation and downward pressure stage; Figure 17 c is the chip removal and rolling stage; Figure 17 d is Figure 17 c is a schematic diagram of the enlarged structure of the local view F;

[0052] Figure 18 The three-dimensional structure of the friction stir welding machine equipped with the stirring tool of the present invention is shown in FIG. Figure 2 ( Figure 18 Shown Figure 1 Inert gas shield for welding not shown);

[0053] Figure 19 for Figure 18 A schematic diagram of the enlarged structure of the local view G in FIG.

[0054] Figure 20 It is a schematic diagram of the three-dimensional structure of the lower rotating support assembled to the frame in the present invention;

[0055] Figure 21 for Figure 20 Schematic diagram of the enlarged structure of the local view H in the figure.

[0056] The meanings of the reference numerals in the figures are:

[0057] 1. Friction stir welding machine, 11. Z-axis drive module, 12. X-axis drive module, 13. Rack, 14. Y-axis drive module, 111. Adapter tool holder, 1111. Rotating interface, 1112. Tool holder core cooling channel, 113. Upper clamping body fixing threaded hole, 2. Rotating jacket module, 21. Jacket housing, 211. Rotating jacket cavity; 22. Jacket bracket; 221. Jacket upper end cover; 222. Jacket lower end cover; 223. Jacket bracket round rod, 231. Jacket air inlet, 232. Toolholder air inlet, 233. Toolholder gas channel, 234. Toolholder air outlet, 241. Jacket second bearing, 242. Jacket second spacer, 243. Jacket second dynamic seal, 251. Jacket first bearing, 252. Jacket first spacer, 253. Jacket first dynamic seal, 3. Mixing tool, 31. Upper clamping body, 311. Upper clamping body core cooling channel, 312. Tool clamping end, 3121. Upper clamping body sealing ring, 313. Rod clamping fixed threaded hole, 32. Pressure regulating nut, 33. Pressure regulating spring Spring, 34, outer sleeve upper end cover, 35, outer sleeve, 351, outer sleeve air inlet, 352, outer sleeve air duct, 353, blowing hole, 353A, first blowing hole, 353B, second blowing hole, 353C, third blowing hole, 354, guide groove, 36, lower clamping body, 37, stirring rod, 37A, homogeneous stirring rod, 37B, stirring head, 371, rod through hole, 372, rod sealing ring, 373, rod fixed section, 374, sleeve limit shoulder, 38, cutting rolling tool, 381, upper cutting Surface, 382, main cutting edge, 383, lower cutting surface, 384, rolling transition arc surface, 385, rolling surface, 386, tool top surface, △h, cutting height, 38A, first cutting rolling tool, 38B, second cutting rolling tool, 38C, third cutting rolling tool, 4, welding platform, 41, workpiece to be welded, 42, welding fixture, 43, inert gas shield with welding, 431, shield shell, 432, mobile plate drive hole, 433, mobile plate shank through hole, 434, mobile plate with welding, 4351, mobile Plate pressure block, 4352, movable plate guide block, 436, protective cover shell fixing hole, 437, inert gas exhaust hole, 5, lower rotating support, 51, support beam, 52, support gasket, 53, upper rotating body, 54, radial support bearing, 541, radial bearing retaining ring, 55, axial support bearing, 551, axial bearing base, 56, reflux oil seal, 57, reflux shell, 571, cooling reflux port, 58, radial bearing bracket, 59, lower rotating body, 6, high-pressure storage tank, 7, pulse solenoid valve, 8, air pipe. DETAILED DESCRIPTION

[0058] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0059] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values of the parts and steps set forth in these embodiments do not limit the scope of the present invention. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to actual proportional relationships. Technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may also include different values. It should be noted that similar numbers and letters represent similar items in the following drawings, and therefore, once an item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0060] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the protection content of the present invention.

[0061] Example 1

[0062] like Figures 1 to 15 as well as Figures 18 to 21As shown, the present invention proposes a stirring tool for through-type stir friction welding, including a rotating jacket module 2, a stirring tool 3, a welding platform 4, and a lower rotating support 5. The stir friction welding machine 1 includes an X-axis drive module 12, a Y-axis drive module 14, and a Z-axis drive module 11 installed on a frame 13. An adapter handle 111 is provided at the lower end of the Z-axis drive module 11. The core of the adapter handle 111 is provided with a handle core cooling channel 1112. The top of the handle core cooling channel 1112 is provided with a rotating interface 1111, which can be adapted to a coolant connector to introduce coolant into the adapter handle 111. The rotating jacket module 2 is integrally mounted on the adapter handle 111 and is fixed to the Z-axis drive module 11 through a jacket bracket 22. The adapter handle 111 can perform relative rotational motion within the rotating jacket module 2. The rotating jacket module 2 includes a jacket housing 21. Inside the jacket housing 21, a first jacket bearing 251, a first jacket spacer 252, a first jacket dynamic seal 253, a second jacket dynamic seal 243, a second jacket spacer 242, and a second jacket bearing 241 are sequentially arranged from top to bottom. An upper jacket end cap 221 and a lower jacket end cap 222 are respectively provided on the upper and lower end surfaces of the jacket housing 21, for axially fixing the first jacket bearing 251 and the second jacket bearing shaft 241 within the jacket housing 21. A rotating jacket cavity 211 is formed between the first and second jacket dynamic seals 253, 243. The adapter handle 111 and the jacket shell 21 are respectively provided with a handle air inlet 232 and a jacket air inlet 231 in the area of the rotating jacket cavity 211. The adapter handle 111 is also provided with a handle air outlet 234 below the rotating jacket module 2. A handle gas channel 233 is also provided inside the adapter handle 111 for connecting the handle air inlet 232 and the handle air outlet 234.

[0063] like Figures 7 to 11As shown, the stirring blade 3 includes an upper clamping body 31, which includes a tool clamping end 312 disposed at the top. The adapter handle 111 is provided with a clamping body fixing threaded hole 113 located around the tool clamping end 312. The upper clamping body fixing threaded hole 113 and the tool clamping end 312 are arranged to fix the upper clamping body 31 to the adapter handle 111. The end of the tool clamping end 312 is provided with an upper clamping body sealing ring 3121 for sealing and preventing coolant from leaking out of the cooling channel. The upper clamping body 31 is fixed to the adapter tool handle 111 through the tool clamping end 312 at its upper end. The upper clamping body 31 is provided with a pressure regulating nut 32, a pressure regulating spring 33, an outer sleeve upper end cover 34 and an outer sleeve 35 from top to bottom; the outer sleeve upper end cover 34 and the outer sleeve 35 are fixedly connected by bolts, and the lower part of the upper clamping body 31 is provided with a guide groove 354 that cooperates with the outer sleeve 35, so that the outer sleeve 35 and the upper clamping body 31 can rotate axially synchronously and can move axially along the axis of the upper clamping body 31; the upper clamping body 31 The middle part of the upper clamping body 31 is provided with an external thread, which is matched with the internal thread of the pressure-adjusting nut 32. The middle part of the upper clamping body 31 is also provided with a sleeve limiting shoulder 374. The pressure-adjusting nut 32 presses the outer sleeve upper end cover 34 against the sleeve limiting shoulder 374 through the pressure-adjusting spring 33. The pressing force can be adjusted by rotating the pressure-adjusting nut 32. The bottom of the upper clamping body 31 is also connected to a lower clamping body 36 made of cemented carbide, which plays the role of a traditional stirring head shoulder. The lower clamping body 36 is a cylindrical structure and a rod through hole 371 is provided at the core. Figure 8 As shown, the upper clamping body 31 is also provided with a rod clamping and fixing threaded hole 313, the core of the stirring rod 37 is provided with a rod through hole 371 for passing the coolant, the top of the stirring rod 37 is also provided with a rod fixing section 373 that cooperates with the rod clamping and fixing threaded hole 313, and the top of the stirring rod 37 is also provided with a rod sealing ring 372 that seals with the upper clamping body 31, as shown in FIG. Figure 16 and Figure 17 As shown, the rod through hole 371 is used to clamp the homogeneous stirring rod 37A or the stirring head 37B.

[0064] The core of the upper clamping body 36 is provided with an upper clamping body core cooling channel 311, the cores of the upper rotating body 53 and the lower rotating body 59 are through holes, the tool handle core cooling channel 1112, the upper clamping body core cooling channel 311, the rod through hole 371, the through hole of the stirring rod 37 core, the through hole of the upper rotating body 53 core, the lower rotating body 59 core and the cooling reflux port 571 on the reflux object 57 are all connected to form a coolant channel.

[0065] like Figures 8 to 13As shown, three sets of carbide cutting and rolling tools 38 are evenly distributed on the bottom of the outer sleeve 35: a first cutting and rolling tool 38A, a second cutting and rolling tool 38B, and a third cutting and rolling tool 38C. The cutting and rolling tools 38 include a top surface 386, an upper cutting surface 381, a lower cutting surface 383, and a rolling surface 385 parallel to the workpiece 41 to be welded. The rolling surface 385 is located on the bottom surface of the cutting and rolling tool 38. The intersection of the upper cutting surface 381 and the lower cutting surface 383 forms the main cutting edge 382. A rolling transition arc surface 384 is provided between the lower cutting surface 383 and the rolling surface 385. A height difference Δh is set between the main cutting edge 382 and the rolling surface 385 (the Δh value is preferably 0.5 to 3 mm). The outer sleeve 35 includes an outer sleeve air inlet 351, an outer sleeve air duct 352 and an air blowing hole 353; there are three air blowing holes 353, namely the first air hole 353A, the second air hole 353B and the third air hole 353C, which are respectively arranged above the upper cutting surface 381 of the first cutting roller 38A, the second cutting roller 38B and the third cutting roller 38C; the outer sleeve air inlet 351 is arranged on the outer wall surface of the outer sleeve 35 for introducing positive pressure inert gas; the outer sleeve air duct 352 is located inside the outer sleeve 35 for connecting the air blowing hole 353 and the outer sleeve air inlet 351.

[0066] like Figure 3 、 Figure 4 、 Figure 6 、 Figures 18 to 21 As shown, the lower rotating support 5 includes a supporting beam 51, a return shell 57, a lower rotating body 59 and an upper rotating body 53; the return shell 57 is fixed to the supporting beam 51 by bolts, the return shell 57 is a cavity structure and a cooling return port 571 is provided at the bottom; the lower rotating body 59 is sequentially covered with radial support bearings 54 and axial support bearings 55 from top to bottom, and the top surface of the return shell 57 is fixed with an axial bearing base 551 and a radial bearing bracket 58 and the outer rings of the corresponding bearings (axial support bearings 55 and radial support bearings 54) are fixed. The upper rotating body 53 is fixed to the top of the lower rotating body 59. A carbide support washer 52 is provided on the top of the upper rotating body 53. The support washer 52 has a through hole for passing the homogeneous stirring rod 37A. Both the upper rotating body 53 and the lower rotating body 59 have a through-core channel for passing coolant. The axial bearing base 551 has a through hole for installing a return oil seal 56. The lower portion of the lower rotating body 59 passes through the return oil seal 56 to prevent the introduced coolant from leaking into the radial support bearing 54 area of the axial support bearing 55. A radial bearing retaining ring 541 is also provided on the top of the lower rotating body 59 to limit the radial support bearing 54 in the Z direction.

[0067] like Figure 14As shown, the welding platform 4 includes a welding inert gas shield 43, the exterior of the welding inert gas shield 43 is a rectangular shield shell 431, and the shield shell 43 is provided with an inert gas exhaust hole 437, so that a constant slightly positive pressure is maintained in the welding inert gas shield 43; the bottom of the shield shell 431 is provided with a shield shell fixing hole 436 for fixing to the welding fixture 42. The shield shell 431 is provided with a welding movable plate 434, a movable plate pressing block 4351 and a movable plate guide block 4352. The welding movable plate 434 is provided with a movable plate shank through hole 433 through which the lower part of the adapter tool handle 11 passes; the welding movable plate 434 is also provided with a movable plate drive hole 432 into which the jacket bracket round rod 223 can be inserted, so that the welding movable plate 434 can follow the stirring tool 2 to move in the X axis during welding.

[0068] like Figure 15 As shown, inert gas protection and positive pressure purging are performed, and the jacket air inlet 231 is connected to the first gas source and the second gas source respectively. The first gas source is a continuous argon protection of 0.05 to 0.1 MPa; the second gas source includes a high-pressure storage tank 6 and a pulse solenoid valve 7, which can provide 0.8 to 1.5 MPa positive pressure argon gas to perform pulse purging on the debris on the surface of the cutting and rolling tool 38 and the workpiece 41 to be welded.

[0069] Example 2

[0070] This embodiment uses the stirring tool in embodiment 1 to perform friction stir welding. Figure 16 As shown, the workpieces 41 to be welded are two 6061 aluminum alloy sheets that require butt-jointed friction stir welding. Each sheet has dimensions of 300 mm long, 100 mm wide, and 8 mm thick. A homogeneous stirring rod 37A, also made of 6061 aluminum alloy, measures 16 mm in diameter, 75 mm in length, and a 5 mm diameter internal through-hole. Through-hole homogeneous eddy current friction stir welding is proposed. A 16 mm diameter through-hole is prefabricated in the weld seam starting area of each workpiece 41. The homogeneous stirring rod 37A and its sealing ring 372 are clamped and secured to the upper clamping body 31. The stirring tool 3 is integrally clamped and secured to the adapter handle 11. The handle's air outlet 234 is connected to the outer sleeve's air inlet 351 via an air pipe 8.

[0071] The process steps of using the stirring tool for through-type friction stir welding in this embodiment are as follows:

[0072] S1: Grind the welding surface of the workpiece 41 to be welded with sandpaper and clean it with alcohol. After cleaning and pretreatment, clamp it to the welding platform 4, rotate the pressure-adjusting nut 32, and adjust the pressure of the pressure-adjusting spring 33 on the outer sleeve 35 to about 120 N; control the homogeneous stirring rod 37A to be inserted into the workpiece 41 to be welded and the support gasket 52 in sequence; Figure 16As shown in a, coolant (preferably water with a pressure of 0.3 MPa and a temperature of 25°C) is introduced from the rotary interface 1111 at the top of the adapter handle 111, so that the coolant passes through the rod through-hole 371 of the homogeneous stirring rod 37A, and finally the coolant is led out of the cooling return port 571 and flows back to the outside of the housing 57;

[0073] S2: If Figure 16 As shown in a, the rolling surface 385 of the cutting rolling tool 38 is controlled to contact the surface of the workpiece 41 to be welded. Figure 15 As shown, the air blowing hole 353 is controlled to start continuously supplying 0.15 MPA low-pressure argon gas;

[0074] S3: If Figure 16 As shown in Figure b, the stirring tool 3 as a whole starts to rotate and press down at a speed of 600 rpm and 3 mm / min. The surface of the workpiece 41 to be welded pushes the outer sleeve 35 to slide upward. The cutting and rolling tool 38 follows the outer sleeve 35 and moves upward relative to the upper clamping body 31 at a speed of 600 rpm and 3 mm / min, so that the cutting and rolling tool 38 is pressed tightly against the upper surface of the workpiece 41 to be welded. The cutting and rolling tool 38 remains relatively stationary in the Z-axis direction.

[0075] S4: After the lower clamping body 36 (equivalent to the stirring shaft shoulder) rotates and presses into the material to be welded 41 to a certain depth (0.4 mm), it keeps rotating for 15 seconds; the rolling surface 385 of the cutting rolling tool 38 is pressed against the surface of the workpiece 41 to be welded with a pressure of about 135 N;

[0076] S5: The stirring tool 3 starts welding along the set weld path according to the set program;

[0077] S6: As Figure 15 、 Figure 16 c and Figure 16 As shown in d, the pulse solenoid valve 7 is opened periodically to provide a pulse debris purge gas source of high-pressure argon gas to the blowing hole 353 (the argon pressure is 1.2 MPa, the cycle is 20 s, and the duration is 1 s);

[0078] S7: Complete the welding task.

[0079] Example 3

[0080] The difference between this embodiment and embodiment 2 is that the stirring rod 37 in this embodiment is not a homogeneous stirring rod 37A, but a traditional stirring head 37B. In this way, when performing transmission stir friction welding operations, it can also provide functions such as inert gas protection, fixed-height burr removal, positive-pressure purging of debris, and surface rolling and shaping, which can also significantly improve the welding quality of the workpiece.

[0081] like Figure 13As shown, the workpieces 41 to be welded are two TC4 titanium alloy plates that need to be butt-stir friction welded, with dimensions of 300 mm long * 100 mm wide * 4 mm thick; a traditional structure stirring head 37B is used, which is made of tungsten-rhenium carbide and is clamped and fixed to the upper clamping body 31; the stirring tool 3 is clamped and fixed as a whole to the adapter tool handle 111; the tool handle air outlet 234 and the outer sleeve air inlet 351 are connected by an air pipe 8.

[0082] The process steps of using the stirring tool for conventional friction stir welding in this embodiment are as follows:

[0083] S1: Grind the welding surface of the workpiece 41 with sandpaper and clean it with alcohol. After cleaning and pretreatment, clamp it to the welding platform 4. Rotate the pressure-adjusting nut 32 to adjust the pressure of the pressure-adjusting spring 33 on the outer sleeve 35 to about 130 N.

[0084] S2: If Figure 17 As shown in a, the rolling surface 385 of the cutting rolling tool 38 is controlled to contact the surface of the workpiece 41 to be welded, as shown in FIG. Figure 15 As shown, the air blowing hole 353 is controlled to start continuously supplying 0.15 MPA low-pressure argon gas.

[0085] S3: If Figure 17 As shown in Figure b, the stirring tool 3 as a whole starts to rotate and press down at a speed of 800 rpm and 1 mm / min. The surface of the workpiece 41 to be welded pushes the outer sleeve 35 to slide upward. The cutting and rolling tool 38 follows the outer sleeve 35 and moves upward relative to the upper clamping body 31 at a speed of 800 rpm and 1 mm / min, so that the cutting and rolling tool 38 is pressed tightly against the upper surface of the workpiece 41 to be welded. The cutting and rolling tool 38 remains relatively stationary in the Z-axis direction.

[0086] S4: After the lower clamping body 36 (equivalent to the stirring shaft shoulder) rotates and presses into the material to be welded 41 to a certain depth (0.15 mm), it keeps rotating for 15 seconds; the rolling surface 385 of the cutting rolling tool 38 is pressed against the surface of the workpiece 41 to be welded with a pressure of about 150 N;

[0087] S5: The stirring tool 3 starts welding along the set weld path according to the set program;

[0088] S6: As Figure 15 、 Figure 17 c and Figure 17 As shown in d, the pulse solenoid valve 7 is opened periodically to provide a pulse debris purge gas source of high-pressure argon gas to the blowing hole 353 (the argon pressure is 1.2 MPa, the cycle is 20 s, and the duration is 1 s);

[0089] S7: Complete the welding task.

[0090] The stirring tool proposed in the present invention can realize inert gas protection, fixed-height burr removal, positive-pressure purging of debris, and surface rolling and shaping during the welding process, thereby significantly improving the welding quality of the workpiece. It has the advantages of simple structure, safety and high efficiency.

[0091] It should be noted that, in this application, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article, or device. In the absence of further restrictions, an element defined by the statement "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0092] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A stirring tool for through-type friction stir welding, characterized in that: It includes an adapter handle and a stirring tool, the stirring tool includes an upper clamping body arranged at the upper part, a lower clamping body arranged at the lower part, and an outer sleeve arranged on the outside of the upper clamping body and the lower clamping body, the upper part of the lower clamping body is connected to the upper clamping body, the upper clamping body and the lower clamping body are provided with a stirring rod, and the upper part of the upper clamping body is connected to the adapter handle; at least one group of cutting and rolling tools are evenly distributed on the bottom of the outer sleeve, the cutting and rolling tools include an upper cutting surface, a lower cutting surface and a rolling surface parallel to the workpiece to be welded, the rolling surface is arranged on the bottom surface of the cutting and rolling tool, the intersection of the upper cutting surface and the lower cutting surface is a main cutting edge, the upper cutting surface is a curved surface, and the height difference between the main cutting edge and the rolling surface is △h.

2. The stirring tool for through-type friction stir welding according to claim 1, characterized in that: The stirring tool also includes a pressure-adjusting nut, a pressure-adjusting spring and an outer sleeve upper end cover which are sequentially mounted on the upper clamping body from top to bottom, and the outer sleeve is arranged at the lower part of the outer sleeve upper end cover; the upper clamping body is provided with a guide groove which cooperates with the outer sleeve, and the guide groove is parallel to the axis of the upper clamping body; the pressure-adjusting nut is provided with an internal thread, and the upper clamping body is provided with an external thread which cooperates with the internal thread of the pressure-adjusting nut; the upper clamping body is also provided with a sleeve limiting shoulder, and the pressure-adjusting spring presses the outer sleeve upper end cover against the sleeve limiting shoulder.

3. The stirring tool for through-type friction stir welding according to claim 1, characterized in that: The core of the adapter tool holder is provided with a tool holder core cooling channel, and the adapter tool holder also includes a rotating interface for introducing coolant into the core of the adapter tool holder; the top of the tool holder core cooling channel is a rotating interface; the core of the upper clamping body is provided with an upper clamping body core cooling channel; the core of the lower clamping body is provided with a rod through hole, and the core of the stirring rod is provided with a through hole; the tool holder core cooling channel, the upper clamping body core cooling channel, the rod through hole and the through hole of the stirring rod core are all connected.

4. The stirring tool for through-type friction stir welding according to claim 1, characterized in that: The outer sleeve also includes an outer sleeve air inlet, an outer sleeve air duct and a blowing hole; the blowing hole is arranged at the bottom of the outer sleeve and above the upper cutting surface of the cutting and rolling tool; the outer sleeve air duct is arranged inside the outer sleeve; the outer sleeve air inlet is arranged on the outer wall surface of the outer sleeve; the setting of the blowing hole can provide continuous inert gas protection and pulse chip blowing gas source for welding.

5. The stirring tool for through-type friction stir welding according to claim 4, characterized in that: It also includes a rotating jacket module that is integrally mounted on the lower part of the adapter handle; the rotating jacket module is used to introduce inert gas into the stirring tool; the rotating jacket module includes a jacket air inlet, and the adapter handle is sequentially provided with a handle air inlet, a handle gas channel and a handle air outlet that are communicated with the jacket air inlet, and the handle gas channel is used to connect the handle air inlet and the handle air outlet; the handle air outlet is connected to the outer sleeve air inlet through an air pipe; the jacket air inlet is connected to the gas source.

6. The stirring tool for through-type friction stir welding according to claim 5, characterized in that: The rotating jacket module includes a jacket bracket, a jacket shell and a jacket bracket round rod, the jacket bracket is fixedly connected to the jacket shell, and the jacket bracket round rod is fixedly connected to the Z-axis drive module of the stir friction welding machine; the interior of the jacket shell is provided with a jacket first bearing, a jacket first spacer, a jacket first dynamic seal, a jacket second dynamic seal, a jacket second spacer and a jacket second bearing in sequence from top to bottom; a rotating jacket cavity is provided between the jacket first dynamic seal and the jacket second dynamic seal, and the tool handle air inlet and the jacket air inlet are respectively located in the rotating jacket cavity.

7. The stirring tool for through-type friction stir welding according to claim 5, characterized in that: The gas source includes a first gas source and a second gas source, the gas pressure of the first gas source is lower than the gas pressure of the second gas source; the jacket gas inlet is connected to the first gas source and the second gas source respectively.

8. The stirring tool for through-type friction stir welding according to claim 1, characterized in that: The invention also includes a welding inert gas protective cover arranged on the welding platform; the outside of the welding inert gas protective cover is a rectangular protective cover shell, and the side of the protective cover shell is provided with an inert gas exhaust hole. The setting of the inert gas exhaust hole enables the welding inert gas protective cover to maintain a constant micro-positive pressure; the bottom of the protective cover shell is provided with a protective cover shell fixing hole for fixing the welding inert gas protective cover on the welding fixture; the protective cover shell is also provided with a welding movable plate, a movable plate pressure block and a movable plate guide block, and the welding movable plate is provided with a movable plate tool handle through hole for the lower part of the adapter tool handle to pass through; the welding movable plate is also provided with a movable plate drive hole for the insertion of the jacket bracket round rod, and the matching setting of the jacket bracket round rod and the movable plate drive hole enables the welding movable plate to follow the stirring tool to perform X-axis movement during welding.

9. The stirring tool for through-type friction stir welding according to claim 1, characterized in that: The cam is fixed on the support beam, and the bottom of the cam is provided with a cooling reflux port; the lower rotating body is provided with a radial support bearing and an axial support bearing in sequence from top to bottom, and the top surface of the cam is fixed with an axial bearing base and a radial bearing bracket, and the axial support bearing and the radial support bearing outer ring are fixed respectively; the upper rotating body is fixed to the upper part of the lower rotating body, and a support gasket is provided on the upper part of the upper rotating body; the support gasket is provided with a gasket through hole for passing the stirring rod; the upper rotating body and the lower rotating body are both provided with a through core channel for passing the coolant; the axial bearing base is provided with a through hole for installing the reflux oil seal; the lower part of the lower rotating body passes through the inner ring of the reflux oil seal.

10. A method for through-type friction stir welding, characterized in that: Using the stirring tool for through-type friction stir welding according to any one of claims 1 to 9 comprises the following steps: S1: After grinding, cleaning and pre-treatment, the workpiece to be welded is clamped on the welding platform, and the pressure regulating nut is loosened and tightened to adjust the pressure of the pressure regulating spring on the outer sleeve to the predetermined value; S2: Control the rolling surface of the cutting rolling tool to contact the surface of the workpiece to be welded, and the blowing hole starts to provide low-pressure argon gas; S3: The stirring tool starts to rotate and press down as a whole, and the cutting and rolling tool moves upward synchronously with the outer sleeve. The rolling surface of the cutting and rolling tool is pressed against the surface of the workpiece to be welded with a certain pressure; S4: After the lower clamping body rotates and presses into the workpiece to be welded to a certain depth, it keeps rotating in place; S5: The stirring tool starts to weld along the set weld path according to the set program; S6: The pulse solenoid valve opens periodically to provide a pulse debris purge gas source of high-pressure argon gas to the blowing hole; S7: Complete the welding task.

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