A method and device for preparing needle-shaped array structure metal fins

Abstract

The present invention discloses a method and device for preparing metal fins with a needle-shaped array structure; it includes two forming processes, namely groove forming and needle-shaped array structure forming. The metal surface is first shaped into a parallel and continuous groove structure with a certain height through the "small accumulation-stable forming" principle, and then a needle-shaped array structure is formed through the "large accumulation-shear failure" principle. The bottom of the metal is separated by cutting to form a continuous strip, and at the same time, the bottom of the metal is separated by cutting to form a three-dimensional fin strip with a continuous bottom and a needle-shaped array structure on the surface. The present invention also provides a device for preparing metal fins with a needle-shaped array structure, which consists of a combined tool unit, a straightening and cutting unit, and a collection unit. The three-dimensional fins prepared by the present invention not only have macroscopic needle-shaped units, but also have microscopic wrinkles, cracks and protrusions on the surface. Therefore, it has great potential in the field of fin manufacturing and heat transfer, and is suitable for industrial promotion and application.

Description

Technical Field

[0001] The present invention relates to the technical field of metal heat exchange fin manufacturing, and in particular to a method and a device for preparing metal fins with a needle-shaped array structure. Background Art

[0002] In the modern electrical industry, with the rapid development of manufacturing processes and microelectronics technology, chips are becoming smaller and more integrated. Conventional cooling methods can no longer meet the heat dissipation needs of highly integrated chips. This leads to heat accumulation within components, affecting the normal use and performance of electronic products and shortening their service life. This has become a major limitation to the development of such technologies. Therefore, a heat dissipation solution with higher heat transfer efficiency is needed.

[0003] Microneedle arrays are a universal substrate for vapor-liquid two-phase conversion, with extremely high energy conversion efficiency. When used as a substrate for vapor-liquid enhanced condensation, microneedle arrays can collect and clean water, making them suitable for applications such as desert water collection and cooling tower water recovery. When used as a substrate for liquid-vapor boiling conversion, microneedle arrays can rapidly achieve high heat transfer through liquid-vapor two-phase conversion, finding applications in electronics cooling and solar power generation. Microneedle arrays are extremely valuable, and research into their fabrication remains a hot topic.

[0004] A microneedle array structure is a structure in which elongated, needle-like units protrude from a target surface in an array arrangement. Unit sizes typically range from 100 to 1000 microns at the mesoscale. Geometric limitations (size and shape) make fabrication difficult and expensive. Current fabrication methods include electrochemical etching, mold printing, and sintering. Ju et al. used electrochemical etching to fabricate microneedle unit structures from copper wire. The resulting needle-like units exhibit a regular, thin, straight needle-like structure suitable for gas droplet condensation. However, the etching step alone takes over 20 minutes, resulting in low processing efficiency. To improve the efficiency of needle-like unit fabrication, a parallel fabrication method for multiple needle-like units has been proposed. A rapidly advancing additive manufacturing method is the bulk deposition technique, which involves laser or etching a porous mold corresponding to the microneedle array topography, followed by metal deposition processes such as electroforming, to achieve large-scale fabrication of a bulk microneedle array. However, the fabrication process requires multiple steps, including mold fabrication, material deposition, and demolding, resulting in a cumbersome process and complex equipment. Powder sintering technology can also be used to manufacture microneedle arrays. Powder is injected into a mold with a pre-set pattern and heated. Once the powder reaches or approaches its melting point, it connects to form a pre-set structure. Sintering technology is applicable not only to metal powders but also to polymer powders. The resulting structure contains a large number of voids, which improves liquid transfer efficiency. Subtractive manufacturing techniques such as micro-milling and electrospark cutting can also produce microneedle structures, but the subtractive process requires multiple machining steps, resulting in low forming efficiency.

[0005] While existing methods can produce microneedle arrays with controllable geometry (shape and size), they suffer from high manufacturing costs, low heat transfer efficiency, and complex processing. Therefore, there is a pressing need to develop a simple and efficient method for preparing microneedle array structures and a corresponding manufacturing device. Summary of the Invention

[0006] The present invention aims to overcome the shortcomings and deficiencies of the prior art and to provide a method and apparatus for preparing a pin-shaped array structured metal fin, thereby improving chip recovery quality and fin heat transfer performance, and being suitable for industrial application and promotion.

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

[0008] A device for preparing a needle-shaped array structure metal fin, comprising:

[0009] A combined tool 200, which is clamped on a lathe and used for machining metal fins with a needle-shaped array structure;

[0010] The straightening and cutting unit is used to straighten and cut the processed metal fins of the needle-shaped array structure;

[0011] A fin collection unit is used to collect the straightened and cut metal fins of the needle-shaped array structure;

[0012] The combined tool 200 includes a tool handle 230, a plowing tool 220 and a cutting tool 240 mounted on the tool handle 230;

[0013] The tool handle 230 includes two steps, one on the upper step and the other on the lower step. The upper step fixes the plowing tool 220 through the first positioning hole 231. The lower step is a receiving groove 235, and the cutting tool 240 is installed through the second positioning hole 232.

[0014] The plowing tool 220 is used to plow the workpiece. It is composed of a plurality of plow blades 221 arranged parallel to each other and equidistantly on the tool body. The blade of each plow blade 221 is a bilaterally symmetrical structure.

[0015] The cutting tool 240 is used for cutting a workpiece, and includes a rake face 241 and a cutting edge 243 .

[0016] The plow blade inclination angle of the plow blade 221 is 30°, the plowing forming angle is 30°, the extrusion forming angle is 0°, and the extrusion gap angle is 0°.

[0017] The cutting tool 240 has a rake angle of 15°, a relief angle of 5°, a blade radius of 0, and a relative plowing depth of 0.05 mm;

[0018] The height between the plow blade 221 and the cutting edge 243 is 4.0 mm.

[0019] The straightening and cutting unit includes: a straightener 300 for straightening the strip of the needle-shaped array structure metal fin; a belt conveyor 500 for transporting the straightened strip of the needle-shaped array structure metal fin; and a cutter 600 for cutting the strip of the needle-shaped array structure metal fin from the belt conveyor 500.

[0020] The fin collection unit includes: an empty box body 730, which is used to accommodate the needle-shaped array structure metal fins cut from the cutting machine 600; an inclined plate 720, which is located on the top side of the empty box body 730, and the top of the inclined plate 720 of the empty box body 730 is in close contact with the top of the lower blade 630 of the cutting machine 600, so that the needle-shaped array structure metal fins can be stably accommodated.

[0021] The bottom of the empty box 730 is equipped with universal wheels 710. The empty box 730 should contain about half the volume of water, which can quickly cool the prepared high-temperature fins and prevent friction and collision when the fins are collected and dropped, thereby protecting its main structure.

[0022] The plowing tool 220 is provided with two positioning holes 222 for facilitating placement of a gasket 260 between the plowing tool 220 and the tool handle 230 to change the plowing depth.

[0023] The cutting tool 240 is provided with two through holes 242 , which correspond to two second positioning holes 232 of the same size on the tool handle 230 , so as to facilitate installation and removal of the cutting tool 240 .

[0024] The tool holder 234 at the bottom of the tool handle 230 is further provided with three parallel third positioning holes 23 to facilitate the installation and positioning of the combined tool 200 and the lathe slide 120.

[0025] A method for preparing a needle-shaped array structure metal fin comprises the following steps:

[0026] 1. Groove forming steps:

[0027] The horizontal lathe 100 is started, causing the spindle to rotate the cylindrical metal workpiece 800. Simultaneously, the combined tool 200 moves in the feed direction to cut the workpiece surface to be machined. Due to the extrusion and accumulation effects of the plowing tool 220, the first deformation zone of the metal undergoes severe shear deformation. When the shear stress reaches the yield strength, the metal is forced to flow along the shear slip line into the forming channel within the plowing tool 220. There, it is then extruded and shaped by the channel sidewalls, causing work hardening and material accumulation in the cutting section, and the metal surface is shaped into a parallel and continuous groove structure.

[0028] 2. Fin preparation steps:

[0029] a Needle-like structure formation

[0030] The grooved cutting layer metal enters the cutting zone. The cutting tool 240 causes the metal to continuously accumulate and deflect. The frictional resistance between the chips and the rake face 241 slows the outflow of the bottom layer of chips, forming a retention layer. However, the accumulation of metal increases the cutting force and the shear component accordingly. Under the dividing action of the cutting tool 240, the bottom of the cutting layer separates from the substrate to form a continuous strip. The middle section - the top of the groove structure accumulates and expands, while the bottom of the groove structure generates shear fracture force, forming a needle-shaped array structure and flowing out along the rake face 241. At this time, a fin prototype with a complete needle-like structure is formed.

[0031] b Continuous fin formation

[0032] When the fin prototype passes through the second deformation zone, the necking and shear cracks further expand, and at the same time, the cutting tool 240 separates the metal bottom by cutting, forming a three-dimensional fin strip with a continuous bottom and a needle-shaped array structure on the surface, and finally the needle-shaped fin 400 is formed;

[0033] 3. Cutting and Collection Steps

[0034] The prepared continuous fins 400 of the needle-shaped array structure pass through the straightening and cutting unit and the collecting unit in sequence, and are straightened and cut by the straightening machine 300 and the cutting machine 600 to obtain the required regular size and complete the cutting;

[0035] Finally, the finished fins that meet the requirements enter the empty box 730 of the fin collection unit and are collected.

[0036] Compared with the prior art, the present invention has the following advantages and effects:

[0037] 1. Among existing technologies for preparing microstructured fins, the extrusion cutting forming technology produces groove-shaped fins with a relatively thick bottom layer structure, a small depth-to-width ratio, and low material utilization. While the plowing extrusion cutting forming technology effectively reduces the bottom layer thickness ratio and increases the depth-to-width ratio of the fin structure, it can only produce two-dimensional groove-shaped fins. The device described in the present invention implements a series of processes from fin preparation to collection, and the prepared needle-shaped array structure fins have a high height, a large aspect ratio, a low base-to-thickness ratio, a richer structure, and a larger specific surface area. These characteristics will significantly increase the turbulence effect and improve heat transfer efficiency.

[0038] 2. In the present invention, the method can be used to cut the end face of a cylindrical workpiece. When the workpiece rotates, the combined tool in the device is used for cutting, and a plurality of parallel continuous grooves are plowed on the surface to be processed of the workpiece. The material between the grooves is squeezed and accumulated by the plow cutter to form a continuous fin prototype. The fin prototype and the bottom are cut and separated by the cutting tool. The fin prototype is formed into a needle-shaped morphology in the cutting area due to the "large accumulation-shear failure" principle. The bottom of the fin prototype is formed into a continuous strip due to the "small accumulation-stable deformation" principle. The cutting tool is used to manufacture a three-dimensional fin strip with an array structure on the surface and a continuous bottom. The processing principle is ingenious and innovative, the method is simple and efficient, and can be directly used in general machine tools. It has strong adaptability, low cost and significant effect.

[0039] 3. The formation mechanism of the pin-shaped fins in the present invention is unique and novel. The combined tool in the device can realize the conversion from the cutting segment to the pin-shaped fin segment. When the initial fin gradually approaches the tool, its shear stress reaches the yield strength, the metal slides along the shear slip line, and the cutting segment undergoes work hardening and material accumulation. Then, due to the obstruction of the plowing tool, the shear deformation in the first deformation zone is quite severe, and the material accumulation and work hardening of the cutting segment increase significantly, resulting in metal necking and fracture. At this time, the cutting segment is transformed into a fin segment. Finally, the fin segment passes through the second deformation zone. Due to the friction effect of the tool rake face, the shear stress is further released, and the necking and shear cracks further expand, finally forming the pin-shaped fin.

[0040] 4. This invention demonstrates the feasibility and high flexibility of the "one-step, two-stage" process, which has great potential in the fields of chip recovery and heat transfer. In practical applications, the feed rate and cutting speed can be changed according to different production needs, and the tool can be replaced to change parameters such as the tool rake angle and plowing depth, making it suitable for industrial application and promotion.

[0041] 5. The material type of the cylindrical workpiece in the present invention is not limited, and different types of materials such as pure copper, aluminum alloy, magnesium alloy, etc. can be selected. The size of the workpiece can also be selected according to specific needs, which can meet the needs of different industries. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a working example diagram of the main devices in the relevant production line involved in the present invention;

[0043] Figure 2 for Figure 1 Right view;

[0044] Figure 3 This is a working example diagram of the combined tool unit of the present invention;

[0045] Figure 4 This is a front view of the combined tool unit of the present invention;

[0046] Figure 5 for Figure 4 Cross-sectional view of section AA;

[0047] Figure 6 This is a schematic diagram of the plowing tool structure of the present invention;

[0048] Figure 7 Schematic diagram of the cutting tool structure of the present invention;

[0049] Figure 8 This is a schematic diagram of the structure of the knife handle of the present invention;

[0050] Figure 9 This is a schematic structural diagram of the straightening and cutting unit of the present invention;

[0051] Figure 10 This is a schematic diagram of the structure of the collection unit of the present invention;

[0052] Figure 11 This is a structural stereogram of the needle-shaped array structure fin prepared by the present invention.

[0053] Figure 12 This is a schematic diagram of the principle of preparing needle-shaped array structure fins according to the present invention.

[0054] Reference numerals in the figure: 100 horizontal lathe; 110 lathe tailstock; 120 lathe slide; 130 lathe motor; 140 three-jaw chuck; 200 combination tool; 210 bolt; 220 plowing tool; 221 plowing tool; 222 positioning hole; 223 plowing tool block; 230 tool holder; 231 first positioning hole; 232 second positioning hole; 233 third positioning hole; 234 tool holder; 235 receiving groove; 240 cutting tool; 241 rake face; 242 through hole; 243 cutting edge; 250 nut; 260 gasket; 300 straightening machine 310 Machine base; 320 Translation mechanism; 330 Clamping roller; 435 Small bolt; 436 Small nut; 440 Large nut; 400 Fin; 410 Needle structure; 420 Fin bottom; 500 Belt conveyor; 510 Motor; 520 Machine frame; 530 Belt; 540 Support mechanism; 600 Cutting machine; 610 Upper tool holder; 620 Crank mechanism; 630 Lower blade; 700 Collecting cart; 710 Universal wheel; 720 Inclined plate; 730 Box; 740 Handle; 800 Cylindrical metal workpiece; 810 Auxiliary roller;

[0055] A Metal in the cutting zone; B Metal accumulation and groove formation; C Needle-shaped structure; D Shear strain increase; E Final structure: F Cutting separation; I--First deformation zone; II--Second deformation zone. DETAILED DESCRIPTION

[0056] The present invention is described in further detail below with reference to specific embodiments.

[0057] Reference Figures 1 to 11 , several embodiments of the method and apparatus for preparing a needle-shaped array structure metal fin of the present invention are given below.

[0058] like Figures 1 to 3 As shown, the present invention provides a method for preparing a needle array structure metal fin, such as Figure 12 As shown, it is carried out in the following steps:

[0059] Step 1: Groove Forming

[0060] The horizontal lathe 100 is started so that the spindle drives the cylindrical metal workpiece 800 to rotate. At the same time, the combined tool 200 moves in the feed direction to cut the workpiece surface to be machined. Due to the extrusion and accumulation effect of the plowing tool 220, the first deformation zone of the metal is subjected to severe shear deformation. When the shear stress reaches the yield strength, the metal is forced to flow along the shear slip line into the forming channel within the plowing tool 220. Then, it is subjected to the extrusion and shaping effect of the channel sidewalls. Work hardening and material accumulation occur in the cutting section. The metal surface is shaped into a parallel and continuous groove structure of a certain height through the "small accumulation-stable forming" principle.

[0061] Step 2: Fin preparation

[0062] a Needle-like structure formation

[0063] The grooved cutting layer metal enters the cutting zone, and the cutting tool 240 causes the metal to continuously accumulate and deflect. The frictional resistance between the chips and the rake face 241 slows the outflow of the bottom chip layer, forming a retention layer. However, the accumulation of metal increases the cutting force and the shear component accordingly. Under the dividing action of the cutting tool 240, the bottom of the cutting layer separates from the substrate to form a continuous strip. The middle and top sections of the groove structure experience significant accumulation and expansion, while the bottom of the groove structure generates a large shear fracture force. Through the "large accumulation-shear failure" principle, a needle-shaped array structure is formed and flows out along the rake face. At this time, a fin prototype with a complete needle-shaped structure is generated.

[0064] b Continuous fin formation

[0065] When the fin prototype passes through the second deformation zone, the necking and shear cracks further expand, and at the same time, the cutting tool 240 separates the metal bottom by cutting, forming a three-dimensional fin strip with a continuous bottom and a needle-shaped array structure on the surface, and the final pin-shaped fin 400 is formed;

[0066] Step 3: Cutting and Collection

[0067] The prepared needle-shaped array structure continuous fins 400 pass through the straightening and cutting unit and the collection unit in turn, and are straightened and cut by the straightener 300 and the cutter 600 to obtain the required regular size. Finally, the finished fins that meet the requirements enter the box of the collection vehicle 700 for collection.

[0068] Specifically, a cross-shaped through groove is opened at one end of the cylindrical metal workpiece 800, and a cross-shaped boss of the same size is also provided at the top of the auxiliary roller 810, so that one end of the workpiece can be perfectly embedded in the roller and fixed, and the other end is supported by the top of the lathe tailstock 110. Therefore, the size of the workpiece can be selected according to specific needs. In addition, the type of workpiece material is not limited, and different types of metals such as pure copper, aluminum alloy, and magnesium alloy can be selected. In this embodiment, pure copper C10200 with a diameter of 70 mm is selected as the cylindrical workpiece, and the workpiece is cut using a C6140A turning machine under dry cutting conditions.

[0069] The cutting edge 243 of the cutting tool 240 is positioned flush with the side centerline of the cylindrical metal workpiece 800, and the cutting direction is perpendicular to the axial direction of the workpiece; the straightening machine 300 is fixed to the outlet of the fin receiving groove of the combined tool 200 with bolts and nuts, so that the distance between the two rollers is exactly equal to the width of the bottom of the cutting layer, that is, the width of the bottom 420 of the fin is prepared; the end of the belt 540 of the belt conveyor 500 is flush with the top of the lower blade 630 of the cutter 600, so that the fin can remain horizontal during the cutting process; the top of the inclined plate 720 of the collection vehicle 700 is in close contact with the top of the lower blade 630 of the cutter 600, so that the fin can be collected smoothly.

[0070] In this embodiment, the rotation speed of the lathe spindle is 50-260r / min, the feed speed of the combined tool 200 is 0.13-0.50mm / r, the total height range of the prepared fin 400 is 2.0-4.0mm, the thickness range of the fin bottom 420 is 0.33-0.40mm, the gap between adjacent needle-shaped structures is considered to be 0, and the distance between the tips of adjacent needle-shaped structures is about 1.89mm, the fin width is about 0.60mm, and its surface also has microscopic wrinkles, cracks and protrusions of 50-200μm; it can be seen that the needle-shaped array structure fin prepared by this method has a high height, a large aspect ratio, a low base thickness ratio, and a larger specific surface area. These better properties will significantly increase the turbulence effect and improve the heat transfer efficiency. Figure 11 shown.

[0071] In this embodiment, the method can be used to cut the end face of a cylindrical metal workpiece 800. When the workpiece rotates, the combined tool 200 in the device is used for cutting, and multiple parallel continuous grooves are plowed on the surface to be processed of the workpiece. The material between the grooves is squeezed and accumulated by the plow 221 to form a continuous fin prototype. The fin prototype and the bottom are cut and separated by the cutting tool 240. The fin prototype is formed into a needle-shaped morphology in the cutting area due to the "large accumulation-shear failure" principle, and the bottom of the fin prototype is formed into a continuous strip due to the "small accumulation-stable deformation" principle. The cutting tool 240 is used to manufacture a three-dimensional fin strip with an array structure on the surface and a continuous bottom. The processing principle is ingenious and innovative, the method is simple and efficient, and can be directly used in general machine tools. It has strong adaptability, low cost and significant effect.

[0072] For some embodiments, since the end face of the workpiece is not necessarily flat, which affects the smoothness of the cutting process, the end face of the workpiece needs to be smoothed before the operation. That is, after assembling the combination tool 200, start the horizontal lathe 100 to make the spindle drive the workpiece to rotate, and at the same time operate the feed box to make the combination tool 200 slowly feed toward the workpiece in a direction perpendicular to the axis of the workpiece to cut off the uneven parts on the surface of the workpiece.

[0073] In the cutting and collecting steps, a step should be added: fin screening, that is, among the large number of fins collected, the needle-shaped array structure fins that meet the requirements should be screened out, especially the batch of fins that do not meet the temperature conditions in the initial stage should be discarded, because the fins prepared in the initial stage are unstable in molding and have poor molding performance due to the low temperature.

[0074] In addition, if Figures 4 to 10 As shown, the device for preparing needle-shaped array structure metal fins of the present invention is composed of a combined tool, a straightening and cutting unit and a collecting unit.

[0075] The combined tool 200 consists of a plowing tool 220, a tool holder 230, and a cutting tool 240. The plowing tool 220 includes a plow blade 221, a positioning hole 222, and a plowing tool block 223, and is used to plow parallel and continuous grooves of a certain height on the surface to be processed of a cylindrical workpiece. The tool holder 230 includes a first positioning hole 231, a second positioning hole 232, a third positioning hole 233, a tool seat 234, and a receiving groove 235 for mounting the tool. The cutting tool 240 includes a rake face 241, a through hole 242, and a cutting edge 243, and is used to cut metal and ultimately produce a three-dimensional fin strip with a needle-shaped array structure on the surface and a continuous bottom.

[0076] In this embodiment, if Figures 4 and 5As shown, the combined tool 200 is made of high-speed steel W18Cr4V, and the distance between the bottom end of the plow blade 221 and the top end of the cutting edge 243 is set to 0.3 mm, that is, the thickness of the bottom 420 of the fin is 0.3 mm, and the height of the groove for accommodating the fin is set to 5.0 mm, leaving sufficient height for the manufactured fin to prevent damage to its structure; two positioning holes 222 are provided on the plowing tool 220, which facilitate the placement of a gasket 260 between the plowing tool 220 and the tool handle 230 to change the plowing depth.

[0077] In this embodiment, if Figure 6 As shown, the plowing tool 220 is composed of a plurality of parallel plow blades 221, which are arranged at equal intervals. In order to prevent deformation and breakage, each plow blade 221 is designed to be bilaterally symmetrical, so that the extrusion force and friction force from the two extrusion surfaces are equal in quantity and opposite in direction; specifically, the geometric parameters of the plowing tool are set as follows: the plow blade inclination angle is 30°, the plowing forming angle is 30°, the extrusion forming angle is 0°, the extrusion gap angle is 0°, the width of a single plow blade 221 is 0.8 mm, the height is 0.8 mm, and the gap between adjacent plow blades 221 is 0.4 mm.

[0078] As a preferred solution, Figure 7 As shown, the cutting tool 240 is provided with two through holes 242, and the corresponding positions on the tool handle 230 also have two second positioning holes 232 of the same size, which are convenient for installation and disassembly of the tool. When installing the tool, the bolt is passed through the positioning hole and then tightened with a nut. When the parameters such as the tool rake angle need to be changed, it is only necessary to change the tool; in this embodiment, the tool rake angle is selected to be 15°, the back angle is 5°, the blade radius is 0, the relative plowing depth is 0.05mm, and the height between the plow blade 221 and the cutting edge 243 is 4.0mm.

[0079] In addition, if Figure 8 As shown, three parallel third positioning holes 233 are provided on the tool seat 234 at the bottom of the tool handle 230, which facilitates the installation and positioning of the combined tool 200 and the lathe slide 120 and is also applicable to various lathes.

[0080] like Figure 9 As shown, the straightening and cutting unit consists of a straightener 300, a belt conveyor 500 and a cutter 600, which are used to straighten, transport and cut the prepared three-dimensional fin strips to obtain the required regular size and then collect them; the straightener 300 consists of a machine base 310, a translation mechanism 320 and a clamping roller 330; the belt conveyor 500 consists of a motor 510, a frame 520, a belt 530 and a supporting mechanism 540; the cutter 600 consists of an upper tool holder 610, a crank mechanism 620 and a lower blade 630.

[0081] In this embodiment, the transport speed of the belt 530 is not set. At this time, the belt conveyor 500 is equivalent to a transition mechanism. On the one hand, the supporting mechanism 540 picks up the fins straightened by the straightening machine 300. On the other hand, the end of the belt 530 is connected to the top of the lower blade 630 of the cutting machine 600, so that the fins can remain horizontal during the cutting process.

[0082] In this embodiment, the motor 510 provides power for the straightening machine 300 and the cutting machine 600. The left and right rollers of the straightening machine 300 are made of rubber to protect the fin structure. The speed of the lathe spindle is set to 50r / min, the feed speed of the combination tool 200 is set to 0.31mm / r, and the two rollers 330 rotate at a constant speed clockwise and counterclockwise respectively, and the speed is set to 100r / min. The upper tool holder 610 falls every 5s and completes a cut with the lower blade 630.

[0083] like Figure 10 As shown, the collecting unit is a collecting cart 700, which consists of a universal wheel 710, an inclined plate 720, an empty box 730 and a handle 740, and is used to collect the prepared fins of regular size; in this embodiment, the top of the inclined plate 720 of the collecting cart 700 is in close contact with the top of the lower blade 630 of the cutting machine 600, so that the fins can be collected smoothly. In addition, the collecting cart 700 is equipped with a universal wheel 710, which can facilitate the adjustment of the cart position and the transportation of the prepared fins.

[0084] As another preferred solution, the collection vehicle 700 should contain about half a tank of water. On the one hand, this can quickly cool the prepared high-temperature fins, and on the other hand, it can prevent friction and collision during fin collection to protect its structure.

[0085] The formation mechanism of the pin-shaped array metal fin structure in the present invention is unique and novel. The combined tool 200 in the device can achieve the conversion from a cutting stage to a pin-shaped fin, which includes two forming processes: groove forming and pin-shaped array structure formation. The metal surface is first shaped into a parallel, continuous groove structure of a certain height through the principle of "small accumulation-stable forming". The pin-shaped array structure is then formed through the principle of "large accumulation-shear failure". The metal bottom is separated by cutting to form a continuous strip. Simultaneously, the metal bottom is separated by cutting to form a three-dimensional fin strip with a continuous bottom and a pin-shaped array structure on the surface.

[0086] In summary, the three-dimensional fins prepared by the present invention not only have macroscopic needle-like units of 2.0-4.0 mm, but also have microscopic wrinkles, cracks and protrusions of 50-200 μm on the surface. They have the advantages of high height, large aspect ratio, low base-to-thickness ratio, and large specific surface area. Therefore, they have great potential in the field of fin manufacturing and heat transfer, and are suitable for industrial promotion and application.

[0087] As described above, the present invention can be implemented better.

[0088] The implementation methods of the present invention are not limited to the above-mentioned embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A device for preparing a needle-shaped array structure metal fin, comprising: A combined tool (200), the combined tool (200) being clamped on a lathe and used for machining needle-shaped array structure metal fins; The straightening and cutting unit is used to straighten and cut the processed metal fins of the needle-shaped array structure; A fin collection unit is used to collect the straightened and cut metal fins of the needle-shaped array structure; Characterized in that the combined tool (200) comprises a tool handle (230), a plowing tool (220) and a cutting tool (240) mounted on the tool handle (230); The tool handle (230) comprises two steps, an upper step and an lower step; the upper step fixes the plowing tool (220) via a first positioning hole (231); the lower step is a receiving groove (235) for mounting the cutting tool (240) via a second positioning hole (232); The plowing tool (220) is used to plow a workpiece, and is composed of a plurality of plow blades (221) arranged parallel to each other and equidistantly on a tool body, wherein the blade of each plow blade (221) is a bilaterally symmetrical structure; The cutting tool (240) is used for cutting a workpiece, and comprises a rake face (241) and a cutting edge (243); The plow blade inclination angle of the plow blade (221) is 30°, the plowing forming angle is 30°, the extrusion forming angle is 0°, and the extrusion gap angle is 0°; The plowing tool (220) is provided with two positioning holes (222) for facilitating placement of a gasket (260) between the plowing tool (220) and the tool handle (230) to change the plowing depth.

2. The device for preparing a needle-shaped array structure metal fin according to claim 1, characterized in that: The cutting tool (240) has a front angle of 15°, a back angle of 5°, a blade radius of 0, and a relative plowing depth of 0.05 mm; The height between the plow blade (221) and the cutting edge (243) is 4.0 mm.

3. The device for preparing a needle-shaped array structure metal fin according to claim 1, characterized in that: The straightening and cutting unit comprises: A straightening machine (300) is used to straighten the strip of metal fins of the needle array structure; A belt conveyor (500) is used to transport the straightened strip of metal fins of the needle-shaped array structure; A cutting machine (600) is used to cut the strip of metal fins with a needle-shaped array structure from the belt conveyor (500).

4. The device for preparing a needle-shaped array structure metal fin according to claim 1, characterized in that: The fin collecting unit comprises: The hollow box (730) is used to receive the metal fins of the needle-shaped array structure cut by the cutting machine (600); The inclined plate (720) is located on the top side of the empty box (730), and the top of the inclined plate (720) of the empty box (730) is in close contact with the top of the lower blade (630) of the cutting machine (600), so that the metal fins of the needle-shaped array structure are stably stored.

5. The device for preparing a needle-shaped array structure metal fin according to claim 4, characterized in that: Universal wheels (710) are installed at the bottom of the empty box (730).

6. The device for preparing a needle-shaped array structure metal fin according to claim 2, characterized in that: The cutting tool (240) is provided with two through holes (242), which correspond to two second positioning holes (232) of the same size on the tool handle (230), facilitating installation and removal of the cutting tool (240).

7. The device for preparing a needle-shaped array structure metal fin according to claim 6, characterized in that: Three parallel third positioning holes (23) are further provided on the tool seat (234) at the bottom of the tool handle (230), facilitating the installation and positioning of the combined tool (200) and the lathe slide (120).

8. A method for preparing a needle-shaped array structure metal fin, characterized in that The method is implemented by using the device for preparing the metal fin with a needle array structure according to any one of claims 1 to 7, comprising the following steps: (1) Groove forming steps: The horizontal lathe (100) is started so that the main shaft drives the cylindrical metal workpiece (800) to rotate, and the combined tool (200) moves along the feed direction to cut the surface of the workpiece to be processed. Due to the extrusion and accumulation effect of the plowing tool (220), the first deformation zone of the metal is subjected to severe shear deformation. When the shear stress reaches the yield strength, the metal is forced to flow along the shear slip line into the forming channel in the plowing tool (220), and then subjected to the extrusion and shaping effect of the channel side wall. Work hardening and material accumulation occur in the cutting section, and the metal surface is shaped into a parallel continuous groove structure. (2) Fin preparation steps: a Needle-like structure formation The metal of the cutting layer with the groove structure enters the cutting zone, and the cutting tool (240) causes the metal to accumulate and turn continuously. The friction resistance between the chip and the front cutting edge (241) causes the flow rate of the chip bottom layer to become slow, forming a retention layer. However, the accumulation of metal makes the cutting force increasingly greater, and the shear component force also increases accordingly. The bottom of the cutting layer is separated from the base material under the dividing action of the cutting tool (240) to form a continuous strip. The middle section-top of the groove structure accumulates and expands, and the bottom of the groove structure generates a shear fracture force, forming a needle array structure and flowing out along the front cutting edge (241). At this time, a fin prototype with a complete needle structure is generated; b Continuous fin formation When the fin prototype passes through the second deformation zone, the necking and shear cracks further expand, and at the same time, the cutting tool (240) separates the metal bottom by cutting, forming a three-dimensional fin strip with a continuous bottom and a needle-shaped array structure on the surface, and finally a needle-shaped fin (400) is formed; (3) Cutting and collection steps The prepared continuous fins (400) of the needle-shaped array structure pass through the straightening and cutting unit and the collecting unit in sequence, and are straightened and cut by the straightening machine (300) and the cutting machine (600) to obtain the required regular size and complete the cutting; Finally, the finished fins that meet the requirements enter the empty box (730) of the fin collection unit to complete the collection.

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