Integrated vortex tube cooled static shoulder friction stir welding tool and apparatus

Abstract

The application discloses an integrated vortex tube cooling static shoulder friction stir welding tool, which comprises a main shaft sleeve, a main shaft is arranged in the main shaft sleeve and is powered by a driving motor, a through heat gas passage is formed in the center of the main shaft along an axial direction, a static shoulder outer shell is fixed to the lower end of the main shaft sleeve and is hollow, a gas flow inlet is formed in the middle side wall of the static shoulder outer shell and is connected with the inside of the static shoulder outer shell, a tool shank is connected with the main shaft and is extended to the inside of the main shaft, a through vortex passage is formed in the center of the tool shank along an axial direction, a plurality of tangential inlets are uniformly formed in the lower part of the tool shank and are connected with the vortex passage, the tangential inlets are inclined from outside to inside and upwards, the middle axis of the gas flow inlet is located between the middle axis of the vortex passage and the lower outer wall of the tool shank in a radial direction and is offset from the middle axis of the tangential inlet, so that eccentric gas supply is realized, a stirring needle, a conical valve and a static shoulder are arranged.

Description

Technical Field

[0001] This invention relates to the field of friction stir welding technology, and more particularly to a static shoulder friction stir welding tool with integrated eddy current tube cooling. Background Technology

[0002] Friction stir welding (FSW) technology has been widely used in the welding of aluminum alloy structural parts in new energy vehicles, aerospace and other fields due to its characteristics such as no fusion welding defects and excellent joint performance. It is especially suitable for connecting key components such as battery tray base plates and frames. However, in actual welding processes, the welding end face of the stationary shoulder and the stirring pin are in a high-temperature friction environment for a long time (the temperature at the root of the stirring pin can reach 520℃ and the temperature at the welding end face of the stationary shoulder can reach 480℃ when there is no cooling). According to statistics, conventional friction stir welding tools with stationary shoulder shells without cooling will show significant wear after welding 10-15 workpieces (about 800-1200m of weld seam) and need to be replaced frequently, which seriously affects the production cycle and is prone to wear, aluminum adhesion and other problems, resulting in short tool life. Frequent tool replacement not only reduces production efficiency, but also affects the consistency of welding. At the same time, high temperature will cause the grains in the welding area to become coarse, reducing the mechanical properties of the joint. In addition, traditional external cooling methods (such as external vortex tubes + cold air pipeline counter-blowing) have defects such as low cold energy utilization, large space occupation and uneven cooling effect, which cannot meet the welding requirements of compact structural parts.

[0003] To address the issue of high-temperature wear on tools, the industry has proposed several cooling solutions: one is natural cooling, which has a simple structure but extremely low cooling efficiency and cannot meet the needs of continuous welding; the other is external vortex tube cooling, which generates cold airflow through an external vortex tube and guides the welding tool through a pipeline for cooling, but the cooling capacity is greatly lost during transmission, and the pipeline layout is cumbersome, easily interfering with the movement of the welding torch, and has poor adaptability.

[0004] The existing cooling methods are as follows: 1. Friction stir welding tools with no cooling or natural cooling of the stationary shaft shoulder shell. These tools do not have any cooling structure and rely on natural heat dissipation to achieve temperature regulation. They have the simplest structure and the lowest cost, but the cooling efficiency is extremely low. During the welding process, the temperature of the stirring pin and the stationary shaft shoulder shell rises rapidly, the continuous welding time is short, the tool wear is severe, and the lifespan is short (conventional tools can not weld more than 20 workpieces continuously). At the same time, the high temperature will cause the grains in the welding area to become coarse and the tensile strength of the joint to decrease, which cannot meet the welding requirements of key structural components. The first solution is only suitable for small-batch, short-weld welding scenarios and cannot be adapted to large-scale production. The second solution is to use an external eddy tube to cool the stationary shoulder shell friction stir welding tool. This solution combines an external eddy tube with a traditional stationary shoulder shell friction stir welding tool. The eddy tube generates a cold airflow, which is guided through the cold air pipeline to the stirring needle and the stationary shoulder shell for cooling. Its shortcomings are: the cold energy is greatly lost during pipeline transmission, the cold energy utilization rate is low, the cooling effect is uneven, and it is impossible to achieve precise cooling of the heat-generating core such as the root of the stirring needle; the external pipeline layout is cumbersome, occupies a lot of space, and easily interferes with the movement trajectory of the welding torch, resulting in poor adaptability and making it unsuitable for welding compact structural parts.

[0005] In summary, existing technologies cannot effectively address the core pain points of static shaft shoulder housing friction stir welding tools, namely "low cooling efficiency, short tool life, low cold energy utilization, and insufficient adaptability." There is an urgent need for a new static shaft shoulder housing friction stir welding tool with integrated eddy tube cooling to fill this technological gap. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and to provide a static shoulder shell friction stir welding tool and equipment with integrated eddy tube cooling. In response to the cooling defects of existing tools, the invention optimizes the cooling channel layout through the integrated design of the eddy tube and the welding tool, thereby achieving efficient and precise cooling of the tool.

[0007] This invention is achieved through the following technical solution: An integrated eddy tube cooled stationary shoulder friction stir welding tool, comprising: The main shaft sleeve has a rotating main shaft inside, which is powered by a drive motor. A through hot air channel is opened along the axial direction at the center of the main shaft. The stationary shaft shoulder housing is fixed to the lower end of the main shaft sleeve and is hollow inside. An airflow inlet that communicates with the interior of the stationary shaft shoulder housing is provided on the middle side wall of the stationary shaft shoulder housing. The tool holder extends into the spindle and connects to it at the top. A through vortex channel is opened in the center of the tool holder along the axial direction. Multiple tangential inlets connected to the vortex channel are evenly opened in the lower part of the tool holder around the circumference. The tangential inlets are inclined upward from the outside to the inside. The central axis of the airflow inlet is located radially between the central axis of the vortex channel and the lower outer wall of the tool holder, and is offset from the central axis of the tangential inlet to achieve eccentric air supply. The stirring needle has its top fixed inside the vortex channel and its bottom passing through the static shaft shoulder housing. A cooling channel is opened along the axial direction in the center of the stirring needle, and multiple gas outlets connected to the cooling channel are evenly opened in the lower part of the stirring needle. A conical valve, wherein the conical valve core is threaded to the inner top of the tool holder, and the conical valve core can be adjusted to move axially, thereby changing the annular flow gap between the conical surface and the inner wall of the vortex channel; The stationary shoulder is fixed to the lower end of the stationary shoulder housing. The stirring needle is located inside the stationary shoulder and its tip passes through the stationary shoulder and extends to the outside of the stationary shoulder.

[0008] A further provision of this technical solution is that the hot gas channel includes, from top to bottom, a hot gas outlet channel, an axial adjustment channel, and a tool holder assembly channel; the axial adjustment channel provides a space for axial adjustment of the conical valve core; and the tool holder assembly channel is used to assemble the tool holder with the spindle.

[0009] A further feature of this technical solution is that the interior of the static shoulder housing includes, from top to bottom, a first cavity, a second cavity, and a third cavity, the inner diameters of the first cavity, the second cavity, and the third cavity gradually decrease, a tapered transition surface is provided between the first cavity and the second cavity, the airflow inlet is located on the outer wall of the second cavity, and an assembly hole communicating with the second cavity is provided on the outer wall of the second cavity, the assembly hole being sealed by a sealing element.

[0010] A further provision of this technical solution is that the inner wall of the static shoulder housing is provided with several ring-shaped dustproof teeth at intervals along the axial direction, and the second dustproof teeth are located in the first cavity; the inner wall of the static shoulder housing is provided with several ring-shaped dustproof teeth at intervals along the axial direction, and the first dustproof teeth are located in the third cavity.

[0011] A further configuration of this technical solution is that the upper part of the tool holder is a tapered part one, and the lower part of the tool holder is a tapered part two and a cylindrical part from top to bottom. An annular protrusion is also provided between the tapered part one and the tapered part two. The tapered part one extends into the spindle and is connected to the spindle.

[0012] A further feature of this technical solution is that the stirring needle, from top to bottom, includes a clamping part, a rotating part, and a needle head. The clamping part extends into the vortex channel and is fixed to the handle. The outer wall of the rotating part is a smooth cylindrical surface. The depth of the cooling channel and the location of the gas outlet need to be clearly defined.

[0013] A further provision of this technical solution is that the conical valve includes a valve seat, which is formed on the top inner wall of the knife handle. The inner diameter of the valve seat is larger than the inner diameter of the vortex channel. A valve core fixing block is provided inside the valve seat. The center of the valve core fixing block is provided with an internal thread. The conical valve core is provided with an external thread. The conical valve core is threadedly connected to the valve core fixing block. An air outlet is also provided at the valve core fixing block.

[0014] A further feature of this technical solution is that the interior of the stationary shaft shoulder is hollow, and two symmetrically arranged heat dissipation holes are opened on the middle side wall of the stationary shaft shoulder, through which the gas outlet exhausts to the outside; at least one chip removal hole is also opened on the lower side wall of the stationary shaft shoulder, and the chip removal hole is arranged horizontally.

[0015] An integrated vortex tube cooled stationary shoulder friction stir welding apparatus, comprising the aforementioned integrated vortex tube cooled stationary shoulder friction stir welding tool.

[0016] An integrated vortex tube cooled stationary shoulder friction stir welding apparatus, comprising the aforementioned integrated vortex tube cooled stationary shoulder friction stir welding tool.

[0017] This invention discloses a stationary shoulder friction stir welding tool with integrated eddy current tube cooling, which, compared with the prior art: This technical solution deeply integrates the eddy current generating structure with the welding tool body, constructing a complete closed loop from airflow introduction and eddy current separation to precise cooling. A through-flow hot air channel is opened at the center of the spindle, and an airflow inlet is opened on the middle side wall of the stationary shoulder housing. Combined with the tangential inlets that are evenly distributed circumferentially at the bottom of the tool holder and tilt upwards from the outside to the inside, and the radial offset of the central axis of the airflow inlet and the tangential inlet to achieve eccentric air supply, the compressed air can quickly establish a high-speed rotating flow field in the vortex channel after entering. Based on the vortex tube effect, the cold airflow and hot airflow are efficiently separated. With the help of the cooling channel axially opened at the center of the stirring pin and the lower circumferential gas outlet, the separated cold airflow is guided directly into the interior of the stirring pin and forced to convect and cool the root area where the heat is intense, and then discharged through the gas outlet. On this basis, the annular flow gap between the conical surface and the inner wall of the vortex channel is changed by the conical valve screwed to the top of the tool holder and its axially movable conical valve core, thereby precisely controlling the split ratio of cold and hot airflow to adapt to different working conditions. Finally, the stirring pin is wrapped by the stationary shoulder fixed at the bottom of the stationary shoulder housing and the welding operation is completed, and the hot airflow is discharged through the hot air channel of the spindle. This effectively solves the problems of large heat loss, inability to accurately target the heat-generating core, and unadjustable cooling intensity in traditional external cooling methods. It avoids rapid wear and aluminum adhesion caused by high temperatures, significantly improves the durability, cooling efficiency, and adaptability to complex welding conditions, and ensures the stability of the welding process and the consistency of joint quality. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0019] Figure 2 A cross-sectional view of the entire invention Figure 1 .

[0020] Figure 3 for Figure 2 A magnified view of side A.

[0021] Figure 4 A cross-sectional view of the entire invention Figure 2 .

[0022] Figure 5 for Figure 4 A magnified view of side B.

[0023] Figure 6 This is a cross-sectional view of the main shaft of the present invention.

[0024] Figure 7 This is a schematic diagram of the structure of the static shoulder housing of the present invention.

[0025] Figure 8 This is a schematic diagram of the structure of the tool holder of the present invention.

[0026] Figure 9 This is a cross-sectional view of the tool holder of the present invention.

[0027] Figure 10 This is a top view of the valve core and valve core fixing block of the present invention.

[0028] Figure 11 This is a schematic diagram of the structure of the stirring needle of the present invention.

[0029] Figure 12 This is a cross-sectional view of the stirring needle of the present invention.

[0030] Figure 13 This is a schematic diagram of the static shoulder structure of the present invention.

[0031] Figure 14 The temperature comparison curve between the tool of this invention and a conventional tool without cooling shows the temperature changes at the root of the stirring pin and the end face of the stationary shaft shoulder during the welding process.

[0032] The numbers and letters in the diagram represent the names of the corresponding components: Wherein: 100, spindle sleeve; 200, spindle; 300, stationary shoulder housing; 400, tool holder; 500, stirring needle; 600, conical valve; 700, stationary shoulder; 201, hot gas passage; 201a, hot gas outlet passage; 201b, axial adjustment passage; 201c, tool holder assembly passage; 301, gas inlet; 302, dustproof tooth two; 303, dustproof tooth one; 304, first cavity; 305 306. Second cavity; 407. Third cavity; 408. Vortex channel; 409. Tangential inlet; 4000. Conical part one; 4000. Conical part two; 401. Cylindrical part; 501. Cooling channel; 502. Gas outlet; 503. Clamping part; 504. Rotating part; 505. Needle head; 601. Conical valve core; 602. Valve seat; 603. Valve core fixing block; 701. Heat dissipation hole; 702. Chip removal hole. Detailed Implementation

[0033] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0034] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0035] Please see Figures 1 to 14 As shown, this application provides a stationary shoulder friction stir welding tool with integrated eddy tube cooling, comprising: The main shaft sleeve 100 has a main shaft 200 rotatably mounted inside it. The main shaft 200 is powered by a drive motor. A through hot air channel 201 is opened in the center of the main shaft 200 along the axial direction. The stationary shaft shoulder housing 300 is fixed to the lower end of the main shaft sleeve 100 and its interior is hollow. An airflow inlet 301 communicating with the interior of the stationary shaft shoulder housing 300 is provided on the middle side wall of the stationary shaft shoulder housing 300. The tool holder 400 extends into the spindle 200 and connects to it. A through vortex channel 401 is axially formed at the center of the tool holder 400. Multiple tangential inlets 402 connected to the vortex channel 401 are evenly formed around the lower part of the tool holder 400. The tangential inlets 402 are inclined upward from the outside to the inside. The central axis of the airflow inlet 301 is located radially between the central axis of the vortex channel 401 and the lower outer wall of the tool holder 400, and is offset from the central axis of the tangential inlet 402 to achieve eccentric air supply. The stirring needle 500 has its top fixed inside the vortex channel 401 and its bottom passing through the static shaft shoulder housing 300. A cooling channel 501 is opened along the axial direction at the center of the stirring needle 500. Multiple gas outlets 502 connected to the cooling channel 501 are evenly opened in the lower circumference of the stirring needle 500. A cone valve 600, wherein the cone valve core 601 of the cone valve 600 is threadedly connected to the inner top of the tool holder 400, and the cone valve core 601 can be adjusted to move axially, thereby changing the annular flow gap between the cone surface and the inner wall of the vortex channel 401. A stationary shoulder 700 is fixed to the lower end of a stationary shoulder housing 300. A stirring needle 500 is located inside the stationary shoulder 700 and its needle tip passes through the stationary shoulder 300 and extends to the outside of the stationary shoulder 300.

[0036] The spindle sleeve 100 provides a mounting base and rotational support for the welding tool. The spindle sleeve 100 is cylindrical, with an annular protrusion at its outer center. Multiple connecting holes are evenly distributed around the annular protrusion, which connects to the mounting frame of the friction stir welding equipment to secure the spindle sleeve 100. The spindle sleeve 100 houses the spindle 200, allowing it to rotate stably under the drive of a motor. The spindle 200 serves as a power transmission component, transmitting rotational torque to the tool holder 400 and stirring needle 500 below. Furthermore, regarding the connection between the spindle 200 and the spindle sleeve 100, the spindle 200 is rotatably mounted inside the spindle sleeve 100. Multiple bearings are installed inside the spindle sleeve 100 to ensure more stable and smooth rotation of the spindle 200. Preferably, see [reference needed]. Figure 6As shown, the spindle sleeve 100 has at least three stepped surfaces inside, each with a fixed bearing. The outer diameter of the bearing gradually increases from bottom to top. The spindle 200 and bearing structure are existing technologies, and those skilled in the art can select them according to actual needs. This article will not elaborate further. Regarding the drive form between the motor and the spindle 200, in this technical solution, the motor is connected to a universal coupling, and the transmission connection between the universal coupling and the spindle 200 is achieved. The universal coupling can also be a universal coupling with a hollow exhaust structure to facilitate subsequent hot air discharge. Of course, this connection form is also existing technology, and those skilled in the art can select it according to actual needs. It should also be noted that the top outer wall of the spindle 200 is also provided with a protrusion, which is used for limiting. This is a conventional technical means.

[0037] The hot air channel 201, which is a through axial channel, is located at the center of the spindle 200. Its function is to provide an exhaust path for the high-temperature airflow generated after vortex separation, so as to avoid heat accumulation inside the tool. The specific size and shape of the hot air channel 201 can be set according to the actual heat dissipation requirements. For example, it can be a cylindrical hole or other polygonal holes. This application embodiment does not make any special limitation on this. The hot air channel 201 is connected to the subsequent vortex generation area to form a complete airflow circulation loop, ensuring that the hot airflow can be quickly discharged to the external environment.

[0038] The stationary shoulder housing 300 is fixed to the lower end of the spindle sleeve 100. Its interior is hollow, and the airflow inlet 301 is located on the middle side wall of the stationary shoulder housing 300 to introduce high-speed compressed gas. The position of the airflow inlet 301 is crucial; it must cooperate with the tangential inlet 402 on the tool holder 400 to guide the gas into the vortex channel 401, thereby allowing the tangential compressed gas to enter the vortex channel 401 inside the tool holder 400 and generating a vortex effect within the vortex channel 401. The stationary shoulder housing 300 can be made of high-temperature resistant and high-wear-resistant materials, such as H13 hot work die steel or other hard alloys, to withstand the high temperatures and frictional loads during welding. It should be noted that a connector is also fixed to the outside of the airflow inlet 301. This connector is connected to the high-speed compressed air via a pipe, and it also has an on / off switch.

[0039] The tool holder 400 is a key transmission component connecting the main shaft 200 and the stirring needle 500, with its upper part extending into the main shaft 200 for coaxial connection. The vortex channel 401 at the center of the tool holder 400 is the core area for generating the vortex effect. High-speed compressed air rotates at high speed within this channel and undergoes temperature stratification. Multiple tangential inlets 402 are evenly spaced circumferentially at the lower part of the tool holder 400. Their upward-inward-sloping angle is designed to impart a strong tangential velocity component to the incoming gas, causing it to quickly form a stable high-speed vortex within the vortex channel 401. The number, tilt angle, and aperture size of the tangential inlets 402 can be adjusted according to the required vortex intensity. For example, four, six, or eight inlets can be set, and the tilt angle can be any value between 15 degrees and 45 degrees. This embodiment does not impose any special limitations on this. The eccentric arrangement of the airflow inlet 301 and the tangential inlet 402, that is, the central axis of the airflow inlet 301 is located between the central axis of the vortex channel 401 and the lower outer wall of the tool holder 400, and the central axes of the two are offset from each other, can further optimize the gas introduction flow pattern, reduce flow resistance, improve swirl efficiency, and ensure that cold air can be generated quickly and transported downward.

[0040] The stirring pin 500 is the component that performs the welding operation. Its top is fixed inside the vortex channel 401 and rotates synchronously with the tool holder 400. The cooling channel 501 at the center of the stirring pin 500 is connected to the vortex channel 401 above, and is used to receive the low-temperature cold airflow after vortex separation. The cold airflow flows from top to bottom in the cooling channel 501, directly providing forced convection cooling to the rod and root of the stirring pin 500, carrying away a large amount of heat generated by friction. Multiple gas outlets 502 circumferentially opened at the lower part of the stirring pin 500 are connected to the cooling channel 501. The cooled gas is ejected through these outlets, which not only completes heat exchange, but also blows and cools the stationary shoulder 700, preventing aluminum adhesion. The stirring pin 500 can be cylindrical, conical, or threaded.

[0041] A conical valve 600 is located at the inner top of the tool holder 400. Its conical valve core 601 is installed via a threaded connection, allowing the operator to adjust its axial position by rotating the conical valve core 601. The size of the annular flow gap formed between the conical surface of the conical valve core 601 and the inner wall of the vortex channel 401 directly determines the splitting ratio and flow rate of the hot and cold airflows. When enhanced cooling is required, the axial position of the conical valve core 601 can be adjusted to increase or decrease this gap (the specific adjustment direction depends on the design of the conical surface orientation), thereby changing the proportion and velocity of the cold airflow. This adjustable mechanism allows the tool to adapt to different welding speeds, plate thicknesses, and material types, solving the problem of poor adaptability of traditional fixed cooling structures.

[0042] The stationary shoulder 700 is fixed to the lower end of the stationary shoulder housing 300. Its main function is to adhere to the workpiece surface during welding, generate frictional heat, and constrain the flow of ductile metal to prevent depressions on the weld surface. The stirring pin 500 passes through the center of the stationary shoulder 700, with its tip extending outwards to insert into the base material. A small gap is typically left between the stationary shoulder 700 and the stirring pin 500 for chip removal, preventing aluminum adhesion and welding debris from entering the internal cooling channels.

[0043] This technical solution constructs a compact welding tool system that integrates eddy current generation, hot and cold separation, internal forced cooling, and adjustable flow rate. By highly integrating the eddy current channel 401, cooling channel 501, and conical valve 600 into the connection structure between the tool holder 400 and the spindle 200, and utilizing the synergistic effect of eccentric air supply and tangentially inclined inlet, a highly efficient eddy current cooling effect is achieved within a limited space. The cold source is directly delivered to the root of the stirring pin where the heat generation is most intense, significantly improving the utilization rate of the cold airflow. At the same time, it can cool the stirring pin 500 and the shoulder 700, greatly extending the life of the stirring pin 500 and the shoulder 700.

[0044] The working process and principle of this application are as follows: Before or during welding, compressed air enters through the airflow inlet 301 on the stationary shoulder housing 300, and is injected at a high speed and at an inclined angle into the vortex channel 401 through the tangential inlet 402 at the lower part of the tool holder 400. Within the vortex channel 401, the gas is subjected to centrifugal force to form a strong high-speed rotating vortex. Based on the vortex tube effect, the rotating airflow undergoes temperature stratification in the axial direction: the gas near the axis decreases in temperature due to expansion and work, forming a cold airflow, while the gas near the tube wall increases in temperature due to friction and compression, forming a hot airflow. The cold airflow enters the cooling channel 501 of the stirring needle 500 from the center of the vortex channel 401, directly cooling the stirring needle 500. After absorbing heat, it is discharged through the gas outlet 502, while simultaneously purging the end face of the stationary shaft shoulder 700. The hot airflow, guided by the conical valve 600 and under the action of pressure difference, moves upward along the inner wall of the vortex channel 401 and flows out through the annular gap between the conical valve core 601 and the vortex channel 401. It is then discharged outside the tool through the hot air channel 201 at the center of the main shaft 200. Moreover, by adjusting the axial position of the conical valve 600, the annular gap between the conical surface and the inner wall of the channel can be changed, thereby precisely controlling the split ratio and total flow of the cold and hot airflows, and achieving the adjustment of the cooling intensity.

[0045] See Figure 6 As shown, Figure 6The diagram shows the segmented structure of the internal hot air channel of the spindle. The hot air channel 201 includes, from top to bottom, a hot air outlet channel 201a, an axial adjustment channel 201b, and a tool holder assembly channel 201c. The axial adjustment channel 201b provides a space for axial adjustment of the tapered reflector block 600. The tool holder assembly channel 201c is used to assemble the tool holder 400 with the spindle 200.

[0046] The hot air outlet channel 201a refers to the channel section located at the uppermost end of the central axis of the spindle 200. Its inner diameter can match the upper structure of the spindle 200, and it is mainly used to guide the high-temperature airflow generated after vortex separation to smoothly exit the tool. This channel is connected to the axial adjustment channel 201b below, forming a complete hot air discharge path, preventing hot air from stagnating inside the spindle and causing heat accumulation, thereby avoiding affecting the rotational accuracy of the spindle 200 and the bearing life. The specific length and inner diameter of the hot air outlet channel 201a can be set according to the actual heat dissipation requirements and the overall structural layout of the spindle 200. For example, it can be a straight cylindrical structure or a flared structure with a slight taper. This application embodiment does not make any special limitations on this.

[0047] The axial adjustment channel 201b refers to the channel section located in the middle of the hot gas channel 201. Its core function is to provide interference-free movement space for the axial displacement of the conical valve core 601. Within this channel, the conical valve core 601 is threaded into the tool holder 400. When adjusting the cooling intensity, the conical valve core 601 is rotated to move axially up and down, changing the annular flow gap between its conical surface and the inner wall of the vortex channel 401. The inner diameter of the axial adjustment channel 201b is typically larger than the inner diameter of the hot gas outlet channel 201a to accommodate the maximum stroke of the conical valve core 601 (e.g., an adjustment range of 0-15 mm), ensuring that the valve core does not rub against or get stuck against the inner wall of the channel during adjustment. The existence of this channel allows the same axial passage to serve both heat flow guidance and mechanical adjustment guidance functions, achieving a compact and integrated structure. The length of the axial adjustment channel 201b can be set according to the required maximum adjustment stroke, for example, it can be 20 mm, 30 mm, or longer; this embodiment does not impose any special limitations on this.

[0048] The tool holder assembly channel 201c refers to the channel section located at the lowest end of the hot air channel 201. Its main function is to achieve a reliable connection and power transmission between the tool holder 400 and the spindle 200. The upper tapered portion 403 of the tool holder 400 extends into this channel and is fixed to the spindle 200 by means of interference fit, tapered surface positioning, or key connection. In this technical solution, the tapered surface positioning is mainly used.

[0049] Through the above technical solution, this application achieves the following beneficial effects: By subdividing the hot gas channel 201 into a hot gas outlet channel 201a, an axial adjustment channel 201b, and a tool holder assembly channel 201c, the three major functions of hot gas outlet, valve core adjustment, and tool holder assembly are rationally arranged and efficiently coordinated within a limited axial space; the dedicated setting of the axial adjustment channel 201b eliminates the risk of mechanical interference during the adjustment process of the subsequent conical valve core 601, ensuring the accuracy and stability of the cold gas flow ratio adjustment, thereby achieving precise control of the welding temperature; the customized design of the tool holder assembly channel 201c improves the connection rigidity and coaxiality between the tool holder 400 and the spindle 200, effectively suppressing vibration under high-speed rotation; overall, this segmented design achieves multi-functional integration and high reliability without increasing the axial dimension of the tool, significantly improving the tool's service life and the consistency of welding quality.

[0050] See Figures 2 to 5 As shown, the interior of the stationary shoulder housing 300 includes, from top to bottom, a first cavity 304, a second cavity 305, and a third cavity 306. The inner diameters of the first cavity 304, the second cavity 305, and the third cavity 306 gradually decrease. A tapered transition surface is provided between the first cavity 304 and the second cavity 305. The airflow inlet 301 is located on the outer wall of the second cavity 305. An assembly hole communicating with the second cavity 305 is also provided on the outer wall of the second cavity 305. The assembly hole is sealed by a sealing element.

[0051] The first cavity 304 refers to the uppermost axially spaced space inside the static shaft shoulder housing 300, with the largest inner diameter among the three cavities. Its primary function is to serve as an initial buffer and pre-swirl zone for high-speed compressed air entering the vortex channel. The second cavity 305 is the intermediate connecting cavity located below the first cavity 304 and above the third cavity 306. Its inner diameter is smaller than the first cavity 304 but larger than the third cavity 306. The second cavity 305 plays a crucial role in acceleration and airflow introduction in the overall design. Since the airflow inlet 301 is located on the outer wall of the second cavity 305, and the inner diameter contracts there, according to fluid mechanics principles, the reduced cross-sectional area significantly increases the velocity of the compressed air flowing through this area, thereby enhancing the tangential kinetic energy of the gas. The relationship between the second cavity 305 and the first cavity 304 is that the buffered airflow provided by the first cavity 304, upon entering the second cavity 305, undergoes energy conversion through cross-sectional contraction, converting pressure energy more efficiently. Converting energy into kinetic energy, and regarding the mounting hole, the purpose of the mounting hole is to assemble the stirring pin 500. Since the stirring pin 500 is a consumable part, it is generally assembled from bottom to top. Therefore, the stirring pin 500 needs to be inserted into the interior of the stationary shoulder housing 300 during assembly. When the stirring pin 500 is inserted into the interior of the stationary shoulder housing 300 from the opening position, and when the stirring pin 500 is inserted into the correct position to assemble with the tool holder 400, the locking bolt is inserted from the mounting hole into the interior of the stationary shoulder housing 300 to fix the stirring pin 500 and the tool holder 400. After the fixing process is completed, the mounting hole is sealed with a sealant to prevent gas leakage during the subsequent cooling process of the stirring pin 500 by introducing high-speed compressed air. In addition, another reason is that some stirring pins 500, due to strength reasons or other design reasons, have an outer diameter of the needle head that is larger than the outer diameter of the rotating shaft, so they can only be installed from bottom to top.

[0052] The third cavity 306 refers to the cavity structure at the lowest point along the axial direction inside the static shoulder shell 300, which has the smallest inner diameter among the three cavities. The conical transition surface refers to the inclined inner wall surface located at the connection between the first cavity 304 and the second cavity 305, and at the connection between the second cavity 305 and the third cavity 306. The function of this conical transition surface is to eliminate the step-like abrupt change that may occur when two cavities with different inner diameters are directly connected, and to avoid severe boundary layer separation or dead zone vortex at the interface, thereby reducing energy dissipation and pressure loss, and achieving a smooth transition.

[0053] See Figures 2 to 5As shown, the inner wall of the stationary shoulder housing 300 is provided with several rings of annular dustproof teeth 302 spaced apart along the axial direction, and the dustproof teeth 302 are located in the first cavity 304; the inner wall of the stationary shoulder housing 300 is provided with several rings of annular dustproof teeth 303 spaced apart along the axial direction, and the dustproof teeth 303 are located in the third cavity 306; the specific shape, size and number of the dustproof teeth 303 and the dustproof teeth 302 can be set according to the actual situation, for example, they can be tiny protrusions with a tooth height of 0.1mm to 0.3mm, and the spacing between adjacent teeth can be 0.5mm. The thickness is up to 1.0 mm, but this embodiment does not specifically limit this. The tool holder 400 has an annular protrusion in the middle, the outer wall of which is smooth. An annular expansion cavity is formed between adjacent dustproof teeth 302. A small radial gap is left between the tip of the dustproof teeth 302 and the middle of the tool holder 400. A sealing cavity is formed between adjacent dustproof teeth 302 for sealing. The inner wall of the stationary shaft shoulder housing 300 is also provided with several annular dustproof teeth 303 spaced axially. The dustproof teeth 303 are located within the third cavity 306. The stirring needle 50... The outer wall of the electrode 0 is a smooth cylindrical surface at the position corresponding to the dustproof tooth 303. An annular expansion cavity is formed between adjacent dustproof teeth 303. A small radial gap is left between the tip of the dustproof tooth 303 and the stirring pin 500, forming a dustproof cavity between adjacent dustproof teeth 303. When external metal debris or particulate dust moves inward with the airflow, it is intercepted and retained in the dustproof cavity through multiple gaps. This effectively prevents metal debris or particulate dust generated during the welding process from entering the vortex channel 401 and the cooling channel 501 of the stirring pin 500, avoiding channel blockage, ensuring smooth cooling airflow, and improving efficiency. As can be seen from the above, the reliability and service life of the tool can be improved by setting two labyrinth seals inside the housing of the stationary shoulder 300. This ensures that when high-speed compressed air is introduced, the tangential compressed air can be more concentratedly introduced into the vortex channel 401 to achieve separation of hot and cold airflow, thereby improving the cooling effect of the cold airflow on the stirring needle 500 and the stationary shoulder 700. At the same time, it can also prevent external metal debris or particulate dust from entering the vortex channel 401. Preferably, the labyrinth seal gap is 0.05-0.15mm.

[0054] See Figure 8 and Figure 9 As shown in the schematic diagram of the outer contour and tapered part of the tool holder, the upper part of the tool holder 400 is tapered part one 403, and the lower part of the tool holder 400 consists of tapered part two 404 and cylindrical part 405 from top to bottom. An annular protrusion is also provided between tapered part one 403 and tapered part two 404. Tapered part one 403 extends into the spindle 200 and is connected to the spindle 200.

[0055] The tapered section 403 refers to the upper structural section of the tool holder 400 used for assembly and connection with the spindle 200. Its outer surface is shaped like a frustum cone. The function of the tapered section 403 is to achieve high-precision coaxiality correction between the tool holder 400 and the spindle 200 by utilizing the self-centering characteristic of the tapered surface fit. Multiple through threaded holes are evenly arranged along the circumference of the annular protrusion. The tool holder 400 is fixed to the spindle 200 through the annular protrusion. In specific implementation, the tapered section 403 extends into the corresponding tapered hole inside the spindle 200, and the two form an interference fit or a tight fit, thereby providing a strong radial clamping force under high-speed rotation conditions and effectively resisting loosening caused by centrifugal force. The fit between the tapered section 403 and the spindle 200 constitutes the starting end of the power transmission chain, ensuring that the rotational torque generated by the drive motor can be stably transmitted to the tool holder 400 and the stirring needle 500 below.

[0056] The second tapered section 404 refers to the transitional structural section located below the annular protrusion and above the cylindrical section 405. Its outer diameter gradually changes from top to bottom or maintains a specific taper. The role of the second tapered section 404 in the overall technical solution is to serve as an intermediate load-bearing section, on the one hand bearing the rotational power from the first tapered section 403, and on the other hand providing support for the cylindrical section 405 below. More importantly, the structural design of the second tapered section 404 can take into account thermal expansion factors. When the tool holder 400 elongates axially due to frictional heat, the inclined structure of the second tapered section 404 can absorb part of the thermal deformation, preventing the lower part of the tool holder 400 from being rigidly squeezed or jammed with the internal components of the stationary shoulder housing 300. The second tapered section 404, the first tapered section 403, and the cylindrical section 405 are connected in sequence to form the main skeleton of the tool holder 400.

[0057] The cylindrical part 405 refers to the columnar structural section at the bottom of the handle 400. Its outer wall is usually a smooth cylindrical surface. The cylindrical part 405 is positioned as the end extension of the handle 400. Its interior usually accommodates the lower section of the vortex channel 401 and the connection structure with the stirring needle 500. The cylindrical part 405 extends into the internal cavity of the stationary shaft shoulder housing 300. The cylindrical part 405 is directly connected to the conical part 404, forming the lower contour of the handle 400.

[0058] The annular protrusion refers to the ring-shaped boss structure set at the junction of the first tapered part 403 and the second tapered part 404. The technical function of the annular protrusion is to serve as an axial positioning reference. When the first tapered part 403 is inserted into the spindle 200, the end face of the annular protrusion can abut against the lower end face of the spindle 200 or not. By centering the tapered surface, the axial installation position of the tool holder 400 in the spindle 200 is precisely defined, thereby ensuring that the vortex channel 401 inside the tool holder 400 and the hot air channel 201 of the spindle 200 are accurately aligned in the axial direction, preventing airflow leakage or increased flow resistance caused by axial misalignment. The annular protrusion is integrally formed with the first tapered part 403 and the second tapered part 404.

[0059] Specifically, in the solution of this application, the tool holder 400 forms a conical surface fit with the spindle 200 through its upper conical part 403, and uses the effect of the conical surface to achieve radial locking and automatic centering, which solves the shortcomings of traditional straight cylindrical connection in maintaining coaxiality; the lower conical part 404 and cylindrical part 405 constitute the overhang end, which, while transmitting torque, buffers thermal expansion stress through the geometric characteristics of the conical part 404, ensuring the structural stability and motion accuracy of the tool holder 400 in high temperature and high speed rotation environment, so that the cooling airflow can be stably formed in the vortex channel 401 and act on the stirring needle 500.

[0060] Through the above technical solution, this application achieves a significant improvement in the connection rigidity and assembly repeatability of the tool holder 400 and the spindle 200 by adopting the tapered part 403 and the tapered surface of the spindle 200 and the axial positioning of the annular protrusion, thereby avoiding vibration and runout under high-speed rotation and ensuring the stability of the cooling airflow channel cross section.

[0061] See Figure 11 and Figure 12 As shown, the stirring needle 500 includes a clamping part 503, a rotating part 504 and a needle head 505 from top to bottom. The clamping part 503 extends into the vortex channel 401 and is fixed to the handle 400. The outer wall of the rotating part 504 is a smooth cylindrical surface.

[0062] The clamping part 503 refers to the uppermost connecting section of the stirring pin 500 along the axial direction. Its function is to achieve a rigid connection and torque transmission between the stirring pin 500 and the tool holder 400. In this application, the clamping part 503 extends into the vortex channel 401 and forms a mating relationship with the tool holder 400. An annular protrusion is also provided between the clamping part 503 and the rotating part 504. This annular protrusion is used to limit the movement of the stirring pin 500 and the tool holder 400 during assembly. The side wall of the clamping part 503 has a threaded groove, which is not connected to the cooling channel 501. The lower part of the tool holder 400 has a threaded hole at the position corresponding to the threaded groove. The irregular structure of the clamping part 503 and the vortex channel 400 are related to the vortex channel 400. The bottom of the flow channel 401 is adapted to achieve precise positioning, and the stirring pin 500 is fixed to the tool holder 400 by means of threaded holes and threaded grooves and bolts. The threaded hole at the bottom of the tool holder 400 is located below the tangential inlet 402. The structural design of the clamping part 503 must ensure that the stirring pin 500 does not slide relative to each other or move axially under high-speed rotation and high axial load conditions, thereby ensuring the stability of airflow communication between the cooling channel 501 and the vortex channel 401. The fixed connection between the clamping part 503 and the tool holder 400 allows the cold airflow to be stably introduced from the vortex channel 401 into the cooling channel 501 inside the stirring pin 500, avoiding airflow leakage or flow field disturbance caused by loose connection.

[0063] The rotating part 504 refers to the intermediate transition section located between the clamping part 503 and the needle head 505. Its outer wall is a smooth cylindrical surface. This smooth cylindrical surface can refer to a continuous curved surface structure with low surface roughness, no threads, no bosses, or no complex contours. The outer periphery of the corresponding dustproof tooth 303 has no sealing protrusions, and the outer circle is smooth overall. During assembly, the stirring needle 500 passes through the opening axially and is assembled with the knife holder 400. Each dustproof tooth 303 is radially aligned with the outer wall of the rotating part 505 of the stirring needle 500, thereby achieving step-by-step sealing.

[0064] The needle head 505 refers to the lowest working section of the stirring needle 500 along the axial direction. Its bottom passes through the stationary shoulder housing 300 and the stationary shoulder 700 and extends to the outside to directly contact the workpiece. The function of the needle head 505 is to insert into the base material to be welded, generate plastic deformation heat through rotational friction, and complete the weld formation. The needle head 505 is connected to the rotating part 504 and receives the torque and axial force transmitted by the rotating part 504. The specific shape of the needle head 505 can be adapted to the welding process requirements. The shape of the needle head 505 can be cylindrical, conical, or threaded. The specific form is set according to the welding process requirements, and this application does not make any special limitations on this. The cooling channel 501 in the center of the stirring needle 500 is connected to the vortex channel 401 above it for... The system receives a low-temperature cold airflow after eddy current separation. The cold airflow flows from top to bottom within the cooling channel 501, directly subjecting the needle head and rotating part of the stirring needle 500 to forced convection cooling, thus removing a large amount of heat generated by friction. Multiple gas outlets 502 circumferentially opened at the lower part of the stirring needle 500 are connected to the cooling channel 501. The cooled gas is ejected through these outlets, which not only completes heat exchange but also blows and cools the stationary shoulder 700. The cooling channel 501 is located inside the clamping part 503 and the rotating part 504. The gas outlets 502 are opened in the rotating part 504 near the needle head 505, that is, the gas outlets 502 are located above the needle head 505 and are horizontally arranged.

[0065] Specifically, the working process and principle of this application are as follows: During welding operations, the drive motor drives the spindle 200 and the tool holder 400 to rotate. The tool holder 400 transmits torque to the stirring needle 500 through the clamping part 503, causing the stirring needle 500 to rotate synchronously. Compressed air enters the vortex channel 401 to form a cold airflow. The cold airflow enters the cooling channel 501 inside the stirring needle 500 through the connection interface between the clamping part 503 and the tool holder 400. The cold airflow flows axially downward, passes through the channel section corresponding to the rotating part 504, and then reaches the needle head 505 and is ejected from the gas outlet 502 to cool the tip of the stirring needle 500 and the stationary shoulder 700. During this process, the clamping part 503 ensures the sealing and stability of the air circuit connection, the rotating part 504 optimizes the mechanical distribution and thermal insulation performance of the rod, and the needle head 505 completes the final release of the cooling medium and welding operation. The three work together to enable the stirring needle 500 to maintain a low working temperature while welding efficiently; the precise exhaust of the needle head 505 achieves directional cooling of the core heating area; thereby achieving the technical effects of improving the fatigue life of the stirring needle, improving the cooling uniformity, and improving the weld formation quality.

[0066] See Figure 9 and Figure 10As shown, the conical valve 600 includes a valve seat 602, which is formed on the top inner wall of the knife handle 400. The inner diameter of the valve seat 602 is larger than the inner diameter of the vortex channel 401. A valve core fixing block 603 is provided inside the valve seat 602. The center of the valve core fixing block 603 is provided with an internal thread, and the conical valve core 601 is provided with an external thread. The conical valve core 601 and the valve core fixing block 603 are threadedly connected. An air outlet is also provided at the valve core fixing block 603.

[0067] The valve seat 602 refers to an annular load-bearing structure directly formed on the inner wall of the top of the tool holder 400. Its inner diameter is designed to be larger than the inner diameter of the vortex channel 401, thereby forming an enlarged receiving chamber inside the tool holder 400. The valve seat 602 is integrally formed with the tool holder 400. It can also be an independent component fixed by interference fit or welding, and this application embodiment does not make any special limitation on this.

[0068] The valve core fixing block 603 refers to an independent bushing assembly embedded inside the valve seat 602, with an internal thread at its center. This valve core fixing block 603 can be fixed by interference fit, welding, pin fixing, or locking with a locking washer; this embodiment does not impose any special limitations on this method, to prevent circumferential rotation during adjustment. The valve core fixing block 603 mates with the external thread of the tapered valve core 601, forming a helical transmission pair. See details. Figure 10 As shown, the valve core fixing block 603 includes two opposing arc-shaped blocks. The inner wall of the arc-shaped block is provided with internal threads, and a gap is left between the two arc-shaped blocks so that subsequent hot air can be discharged to the outside through the annular gap upwards and through the gap. In addition, it should be noted that the bottom surface of the valve core fixing block 603 can abut against the bottom surface of the valve seat 602 or be higher than the bottom surface of the valve seat 602, which can be selected according to actual needs.

[0069] The conical valve core 601 refers to an adjusting element with a conical outer surface. Its upper part has an external thread that matches the valve core fixing block 603, and the upper part is cylindrical. When the operator rotates the conical valve core 601, guided by the valve core fixing block 603, the conical valve core 601 moves axially up and down, thereby changing the annular flow gap between its conical surface and the inner wall of the vortex channel 401. The conical valve core 601 can be made of high-temperature resistant alloy steel or hard alloy to resist high-speed airflow erosion and high-temperature environments. It is worth noting that the top of the conical valve core 601 is recessed with a shaped groove. When adjustment is required, the adjusting member can be inserted from the top of the main shaft 200 until it abuts against the shaped groove, and then the adjusting member can be rotated to control the conical valve core 601 to rotate, thereby achieving the purpose of adjusting the annular gap. The cone angle of the conical valve core 601 can be set according to the actual required flow rate adjustment sensitivity, for example, it can be 30 degrees, 45 degrees or 60 degrees. This application embodiment does not make a special limitation on this. The bottom conical surface of the conical valve core 601 is located in the vortex channel 401, and the bottom of the conical valve core... The conical surface can also guide the uniform distribution of cold airflow, ensuring uniform cooling effect, and the proportion of cold airflow can be adjusted to adapt to different cooling needs. In addition, it should be noted that although the conical valve core 601 is designed to be axially adjustable in this technical solution, in actual use, a size of the annular gap is usually set directly before assembly. When adjustment is required, although the operation is relatively complicated, the adjustment function can still be achieved. It is only necessary to separate the drive motor and universal coupling from the main shaft 200, and then the adjusting part can be inserted to adjust the conical valve core 601 axially.

[0070] The vent refers to the gap between the two valve core fixing blocks 603. This vent is connected to the vortex channel 401 through the annular gap.

[0071] Specifically, the working process and principle of the conical valve 600 in this application are as follows: During assembly, a fixed annular gap size is set. After assembly, a start-up test is performed, and the temperatures of the stirring needle and the stationary shaft shoulder are recorded. If no adjustment is needed, it can be used directly. If adjustment is required, the external drive source is separated from the main shaft, and the conical valve core 601 is rotated manually. Because the valve core fixing block 603 restricts the circumferential freedom of the conical valve core 601 but allows its axial displacement, the conical valve core 601 moves axially in a linear motion along the threaded trajectory. As the conical valve core 601 moves in or out, the size of the annular gap formed between it and the inner wall of the vortex channel 401 changes, thereby controlling the proportion of airflow entering the vortex tube effect zone. During this process, the valve seat 602 provides a stable support platform, and the valve core fixing block 603 ensures the precision of the transmission. Once adjustment is complete, the external drive source is connected to the main shaft for actual machining.

[0072] See Figure 13 As shown, the interior of the stationary shoulder 700 is hollow. Two symmetrically arranged heat dissipation holes 701 are opened on the middle side wall of the stationary shoulder 700, and the gas outlet 502 exhausts gas to the outside through the heat dissipation holes 701. At least one chip removal hole 702 is also opened on the lower side wall of the stationary shoulder 700, and the chip removal hole 702 is arranged horizontally.

[0073] The stationary shoulder 700 refers to the component located at the lowest end of the welding tool, directly contacting the workpiece surface and generating frictional heat. Its interior is a hollow structure, the specific shape of which can be determined according to actual conditions; for example, it can be a cylindrical cavity or a conical cavity. This application embodiment does not impose any special limitations on this. Two symmetrically arranged heat dissipation holes 701 are provided on the middle sidewall of the stationary shoulder 700. These heat dissipation holes 701 are through holes connecting the internal hollow cavity of the stationary shoulder 700 to the external environment, and their positions typically correspond to the injection path of the gas outlet 502 of the stirring pin 500. The design of the heat dissipation holes 701 is primarily for heat dissipation from the stationary shoulder 700. Simultaneously, the heat dissipation holes 701 also provide an exhaust channel for the low-temperature airflow after heat exchange through the internal cooling channel 501 of the stirring pin 500, allowing the cold airflow to directly act on the stationary shoulder 700. In the system linkage, the cold air jet from gas outlet 502 can also act on the inner cavity of stationary shoulder 700. In this process, it carries away the heat accumulated in stationary shoulder 700, forming forced convection cooling, thereby reducing the operating temperature of stationary shoulder 700 and suppressing the occurrence of aluminum sticking.

[0074] The lower sidewall of the stationary shoulder 700 is also provided with at least one chip removal hole 702. During friction stir welding, the semi-molten alloy overflows upwards through the gap between the stirring pin 500 and the stationary shoulder 700. This chip removal hole 702 serves as a channel for discharging metal chips or oxide scale generated during the welding process. The chip removal hole 702 is horizontally positioned, meaning its axis is perpendicular to the central axis of the stationary shoulder 700 and parallel to the workpiece surface. This horizontal structural feature allows for the efficient ejection of chips accumulated in the lower inner cavity of the stationary shoulder 700 using centrifugal force during tool rotation. In the system linkage, the chip removal hole 702 works in conjunction with the hollow inner cavity of the stationary shoulder 700 and the heat dissipation hole 701: the hollow inner cavity serves as a temporary chip containment area, preventing chips from directly entering precision-fitted parts; the chip removal hole 702 is responsible for periodically cleaning these chips, preventing them from clogging the heat dissipation hole 701 or interfering with the normal flow path of the cooling airflow, ensuring the long-term stable operation of the cooling system. The number of chip removal holes 702 can be one or more, evenly distributed circumferentially, and their cross-sectional shape can be circular, elliptical or rectangular. This application embodiment does not make any special limitation on this.

[0075] Specifically, the working process and principle of this application are as follows: During the welding process, the cold air separated by the vortex tube effect of compressed air enters the cooling channel 501 of the stirring pin 500, cools the stirring pin 500, and then sprays out from the gas outlet 502 into the hollow inner cavity of the stationary shoulder 700. At this time, the low-temperature airflow diffuses in the inner cavity of the stationary shoulder 700, absorbing the heat transferred from the stationary shoulder 700. Subsequently, most of the airflow is discharged outward through the heat dissipation hole 701 on the middle side wall, which can also blow away the contact area between the end face of the stationary shoulder 700 and the workpiece, thereby achieving cooling. Meanwhile, if a small amount of metal debris generated during the welding process enters the inner cavity of the stationary shoulder 700, it will be thrown towards the lower inner wall of the stationary shoulder 700 under the centrifugal force generated by the high-speed rotation of the tool, and finally discharged outside the tool through the horizontally set chip removal hole 702, thereby keeping the inner cavity clean, ensuring the unobstructed flow of the heat dissipation hole 701 and the stability of cooling efficiency; moreover, since the stirring needle 500 always maintains high-speed rotation, it can form two fan-shaped air curtains above the needle head 505 through the gas outlet 502, which can largely block metal debris and prevent metal debris from splashing upwards during processing.

[0076] This application also provides a stationary shoulder friction stir welding apparatus with integrated vortex tube cooling, comprising the stationary shoulder friction stir welding tool with integrated vortex tube cooling as described above.

[0077] Among them, the stationary shoulder friction stir welding equipment with integrated eddy tube cooling refers to a complete mechanical system or automated production line unit used to perform the stationary shoulder friction stir welding process. The core function of this equipment is to carry and drive the aforementioned welding tools to achieve efficient and high-quality joining of metal materials such as aluminum alloys.

[0078] See Figure 14 As shown, Figure 14 The temperature comparison curve between the tool of this invention and a conventional non-cooled tool shows the temperature changes at the root of the stirring pin and the end face of the stationary shaft shoulder during the welding process. As can be seen from the above comparison, the tool using this technical solution can significantly reduce the temperature of the stirring pin and the stationary shaft shoulder during friction stir welding, thereby achieving the technical effect of extending the service life of the tool.

[0079] Preferably, the diameter of the stirring needle is 20mm (suitable for welding 4-6mm thick aluminum alloy), and the diameter of the central cooling channel is 6-10mm (preferably 8mm).

[0080] Example 1 (Basic Scheme) In the welding of a battery tray for a certain type of new energy vehicle, the object being welded is the lap joint between the 4mm thick 6061-T6 aluminum alloy battery tray base plate and the frame. The welding is performed using the static shoulder friction stir welding tool with integrated eddy current tube cooling as described in this invention. The specific implementation process is as follows: 1. Tool parameter settings: stirring needle diameter 20mm, central cooling channel diameter 8mm; vortex chamber inner diameter 48mm, axial length 100mm, annular gap 14mm; conical valve core in initial position (not adjusted); labyrinth seal gap 0.1mm.

[0081] 2. Cooling medium parameters: Compressed air pressure 0.55MPa, flow rate 200L / min.

[0082] 3. Welding parameters: Welding speed 800mm / min, stirring needle rotation speed 1300r / min, static shaft shoulder pressure 5kN.

[0083] 4. Welding process: Compressed air is introduced in advance, and after the tool has been pre-cooled for 30 seconds, the welding equipment is started. The stirring needle is inserted into the base material by rotation, and the stationary shoulder is in contact with the surface of the workpiece to perform lap joint welding. During the welding process, compressed air is continuously introduced, and the cold airflow cools the stirring needle through the central cooling channel and is discharged through the return channel. The tool temperature is controlled in real time.

[0084] 5. Performance test results: During the welding process, the temperature at the root of the stirring needle remained stable at 380℃, and the temperature at the end face of the stationary shaft shoulder remained stable at 350℃. After welding 20 workpieces continuously (total weld length 1500m), the tool was inspected. The stirring needle showed no obvious wear, and there was no aluminum adhesion at the end face of the stationary shaft shoulder. The tool was in good condition. The weld was smooth and free of defects such as dents and flash. The tensile strength of the joint reached more than 230MPa, meeting the requirements for battery tray use. The tool life was increased by 1.3 times compared with conventional non-cooled tools.

[0085] Example 2 (High-speed welding condition) For high-speed welding scenarios, the tool parameters and cooling parameters are adjusted. The specific implementation process is as follows: 1. Tool parameter adjustment: Adjust the conical valve core inward by 5mm to increase the proportion of cold airflow; other structural parameters are the same as in Example 1.

[0086] 2. Cooling medium parameters: Adjust the compressed air pressure to 0.65MPa and the flow rate to 260L / min to improve cooling intensity.

[0087] 3. Welding parameters: Welding speed increased to 1500 mm / min, stirring needle rotation speed 3000 r / min, static shaft shoulder pressure 12 kN.

[0088] 4. Welding process: Same as in Example 1, but by adjusting the position of the tapered reflector block and the parameters of the cooling medium, it is adapted to the high-temperature working conditions of high-speed welding.

[0089] 5. Performance test results: During the welding process, the temperature at the root of the stirring pin was controlled below 420℃, and the temperature at the end face of the stationary shaft shoulder was controlled below 360℃, meeting the cooling requirements of high-speed welding; after welding 25 workpieces continuously (total weld length 1870m), the tool showed no significant wear; the weld formation was good, with no defects such as incomplete fusion or depressions, and the joint performance met the requirements, achieving a balance between high-speed welding and long tool life.

[0090] Comparative example (conventional non-cooled stationary shoulder friction stir welding tool) A conventional friction stir welding tool without a cooling stationary shoulder was used to weld the workpiece of Example 1. The parameters were as follows: stirring pin diameter 20mm, no cooling channel; welding speed 1300mm / min, stirring pin rotation speed 2800r / min, stationary shoulder pressure 10kN; other conditions were the same as in Example 1.

[0091] Welding results show that during the welding process, the temperature at the root of the stirring needle rapidly rises to 520℃, and the temperature at the end face of the stationary shaft shoulder rises to 480℃. After welding 15 workpieces continuously (total weld length 1000m), the stirring needle shows obvious wear, and the end face of the stationary shaft shoulder shows severe aluminum adhesion, rendering the tool unusable. It cannot meet the requirements for battery tray use. The tool has a short lifespan and requires frequent replacement, which seriously affects production efficiency.

[0092] The comparison between this embodiment and the comparative example shows that the integrated eddy tube cooling structure of the present invention can effectively reduce tool temperature, significantly improve tool life, and improve weld formation and joint performance. It is completely superior to conventional uncooled tools and can be adapted to the needs of large-scale production.

[0093] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A static shoulder friction stir welding tool with integrated eddy current tube cooling, characterized in that, include: The main shaft sleeve (100) has a rotating main shaft (200) inside. The main shaft (200) is powered by a drive motor. A through hot air channel (201) is opened in the center of the main shaft (200) along the axial direction. The stationary shoulder housing (300) is fixed to the lower end of the main shaft sleeve (100) and its interior is hollow. An airflow inlet (301) is provided on the middle side wall of the stationary shoulder housing (300) and communicates with the interior of the stationary shoulder housing (300). The tool holder (400) extends into the spindle (200) and is connected to the spindle (200). A through vortex channel (401) is provided in the center of the tool holder (400) along the axial direction. A plurality of tangential inlets (402) connected to the vortex channel (401) are evenly provided in the lower part of the tool holder (400) in the circumferential direction. The tangential inlets (402) are inclined upward from the outside to the inside. The central axis of the airflow inlet (301) is located in the radial direction between the central axis of the vortex channel (401) and the lower outer wall of the tool holder (400), and is offset from the central axis of the tangential inlet (402) to achieve eccentric air supply. The stirring needle (500) has its top fixed inside the vortex channel (401) and its bottom passing through the static shaft shoulder housing (300). A cooling channel (501) is opened in the center of the stirring needle (500) along the axial direction. Multiple gas outlets (502) connected to the cooling channel (501) are evenly opened in the lower part of the stirring needle (500) in the circumferential direction. A cone valve (600) has a cone valve core (601) that is threaded onto the inner top of a knife holder (400). The cone valve core (601) is adjustable to move axially, thereby changing the annular flow gap between the cone surface and the inner wall of the vortex channel (401). A stationary shoulder (700) is fixed to the lower end of a stationary shoulder housing (300), and a stirring needle (500) is located inside the stationary shoulder (700) with its needle tip passing through the stationary shoulder (300) and extending to the outside of the stationary shoulder (300).

2. The static shoulder friction stir welding tool with integrated eddy current tube cooling according to claim 1, characterized in that, The hot air passage (201) includes, from top to bottom, a hot air outlet passage (201a), an axial adjustment passage (201b), and a tool holder assembly passage (201c); the axial adjustment passage (201b) provides a space for axial adjustment of the conical valve core (601); the tool holder assembly passage (201c) is used to assemble the tool holder (400) with the spindle (200).

3. The stationary shoulder friction stir welding tool with integrated eddy current tube cooling according to claim 1, characterized in that, The interior of the static shaft shoulder housing (300) includes, from top to bottom, a first cavity (304), a second cavity (305), and a third cavity (306). The inner diameters of the first cavity (304), the second cavity (305), and the third cavity (306) gradually decrease. A tapered transition surface is provided between the first cavity (304) and the second cavity (305). The airflow inlet (301) is located on the outer wall of the second cavity (305). An assembly hole communicating with the second cavity (305) is also provided on the outer wall of the second cavity (305). The assembly hole is sealed by a sealing element.

4. The stationary shoulder friction stir welding tool with integrated eddy current tube cooling according to claim 3, characterized in that, The inner wall of the static shaft shoulder housing (300) is provided with several ring-shaped dustproof teeth (302) spaced apart along the axial direction, and the dustproof teeth (302) are located in the first cavity (304); the inner wall of the static shaft shoulder housing (300) is provided with several ring-shaped dustproof teeth (303) spaced apart along the axial direction, and the dustproof teeth (303) are located in the third cavity (306).

5. The stationary shoulder friction stir welding tool with integrated eddy current tube cooling according to claim 1, characterized in that, The upper part of the handle (400) is a tapered part one (403), and the lower part of the handle (400) consists of a tapered part two (404) and a cylindrical part (405) from top to bottom. An annular protrusion is also provided between the tapered part one (403) and the tapered part two (404). The tapered part one (403) extends into the spindle (200) and is connected to the spindle (200).

6. The stationary shoulder friction stir welding tool with integrated eddy current tube cooling according to claim 1, characterized in that, The stirring needle (500) comprises, from top to bottom, a clamping part (503), a rotating part (504), and a needle head (505). The clamping part (503) extends into the vortex channel (401) and is fixed to the handle (400). The outer wall of the rotating part (504) is a smooth cylindrical surface. The depth of the cooling channel and the location of the gas outlet need to be clearly defined.

7. The stationary shoulder friction stir welding tool with integrated vortex tube cooling according to claim 1, characterized in that, The conical valve (600) includes a valve seat (602), which is formed on the top inner wall of the knife handle (400). The inner diameter of the valve seat (602) is larger than the inner diameter of the vortex channel (401). A valve core fixing block (603) is provided inside the valve seat (602). The valve core fixing block (603) has an internal thread at its center. The conical valve core (601) has an external thread. The conical valve core (601) is threadedly connected to the valve core fixing block (603). An air outlet is also provided at the valve core fixing block (603).

8. The stationary shoulder friction stir welding tool with integrated eddy current tube cooling according to claim 1, characterized in that, The stationary shoulder (700) is hollow inside. Two symmetrically arranged heat dissipation holes (701) are opened on the middle side wall of the stationary shoulder (700). The gas outlet (502) exhausts gas to the outside through the heat dissipation holes (701). At least one chip removal hole (702) is also opened on the lower side wall of the stationary shoulder (700). The chip removal hole (702) is horizontally arranged.

9. A static shoulder friction stir welding device with integrated eddy current tube cooling, characterized in that, A stationary shoulder friction stir welding tool comprising integrated vortex tube cooling as described in any one of claims 1-8.

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