Method for preparing capillary structure on inner wall of heat pipe red copper tube

Abstract

This invention discloses a method for preparing capillary structures on the inner wall of a copper heat pipe, belonging to the field of heat pipe technology. S1: A heat pipe is formed using copper powder. A coating is sprayed along the length of the outer surface of the heat pipe to form a spray line. The heat pipe is then cut into sections and sequentially labeled as b1, b2, b3… up to b… （n‑1） S2. Using an auxiliary connector, b1 and b2 are aligned coaxially to form the b1b2 connecting pipe section and the spraying line; S3. A cathode core rod is placed at the axial position of the b1b2 connecting pipe section using a positioning device; S4. The b1b2 connecting pipe section is placed in a tank containing electrolyte for electrolysis; after electrolysis, the auxiliary connector is removed; S5. Referring to steps S2~S4, b2b3…b （n‑1） Electrolysis is performed on the bn connecting pipe section; b2b3…b （n‑1） Once connected, it becomes the required heat pipe, with the spray lines aligned during connection. The benefits are: low cost, guaranteed uniformity of the capillary electrolytic thickness on the inner wall of the heat pipe, and low thermal resistance.

Description

Technical Field

[0001] This invention belongs to the field of heat pipe technology, and in particular relates to a method for preparing capillary structures on the inner wall of a copper heat pipe. Background Technology

[0002] Heat pipes are a type of high-efficiency phase change heat transfer element. Their working principle is to achieve rapid heat transfer by utilizing the cyclic process of the working fluid absorbing heat and vaporizing in the evaporation section and releasing heat and liquefying in the condensation section. They have advantages such as high thermal conductivity, good isothermal properties, and compact structure, and are widely used in fields such as heat dissipation of electronic devices, aerospace thermal control, waste heat recovery, and new energy.

[0003] To enable the heat transfer function of a heat pipe, a capillary structure needs to be formed on its inner wall. Currently, there are two main processes for fabricating capillary structures on the inner wall of a heat pipe: The first process involves sintering copper powder onto the inner wall of the heat pipe. However, this method has several drawbacks: it requires large-scale high-temperature sintering equipment, resulting in high investment costs, large production line footprint, and extremely high energy consumption; the sintering temperature, holding time, and cooling rate are strictly controlled, leading to a very low tolerance for process errors; the overall uniform sintering of large-length, large-diameter heat pipes is difficult, easily resulting in looseness, detachment, and uneven density; the process is complex, the production cycle is long, the yield rate is low, and the manufacturing cost remains high. The second process involves weaving a copper mesh into the inner wall of the heat pipe. The copper mesh is an independent component that only physically adheres to the inner wall of the copper pipe. However, the copper mesh and the inner wall of the heat pipe are not integrated and cannot adhere well, leaving gaps at the interface. This results in a significantly higher contact thermal resistance, greatly reducing the overall heat conduction and heat transfer efficiency of the heat pipe. Under hot and cold cycling conditions, it is prone to displacement, loosening, and deformation, resulting in poor structural stability, short service life, and inability to meet the requirements for high-power, high-heat-flux heat pipes.

[0004] Both of the above traditional processes involve adding capillary structures to the inner wall of the heat pipe, rather than using the original structure of the pipe wall. This makes quality control difficult, the produced products have high thermal resistance, and poor adaptability, especially when processing large heat pipes. In addition, these two traditional processes require heavy assets, with large upfront investments and high costs.

[0005] Therefore, the industry urgently needs a brand-new manufacturing process that can improve the performance of heat pipes (very low thermal resistance) while also being low in cost and easy to mass-produce. Summary of the Invention

[0006] The purpose of this invention is to solve the problem that the cathode core rod is prone to radial displacement during the electrolytic processing of the inner wall of a heat pipe due to the lack of an active centering and positioning structure, and to propose a method for preparing capillary structures for the inner wall of a copper heat pipe.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: S1. A heat pipe is fabricated using copper powder. A coating is sprayed along the length of the heat pipe's outer surface to form a spray line. The heat pipe is then cut into sections with a length of 60mm or less and sequentially labeled as b1, b2, b3… up to b… （n-1） bn; S2. Connect the cut ends of b1 and b2 together, align the spray lines, and use an auxiliary connector to make b1 and b2 coaxially connected to form a whole pipe section - called the b1b2 connecting pipe section; S3. A cathode core rod 3 is placed at the axial position of the b1b2 connecting pipe section using a positioning device, and the distance between the outer cylindrical surface of the cathode core rod 3 and the inner wall of the corresponding b1b2 connecting pipe section is consistent. S4. Place the b1b2 connecting pipe section containing the cathode core rod 3 into the tank containing electrolyte, so that the electrolyte can enter the b1b2 connecting pipe section and the upper part of the b1b2 connecting pipe section is not submerged by the electrolyte; connect the cathode core rod 3 to the negative terminal of the power supply and connect the b1b2 connecting pipe section to the positive terminal, and then perform electrolysis. After electrolysis is complete, remove the auxiliary connector; S5. Referring to steps S2~S4, electrolyze the b2b3 connecting pipe section formed by the butt joint of b2 and b3, and then sequentially electrolyze the b3b4 connecting pipe section, the b4b5 connecting pipe section…b （n-1） Electrolysis is performed on the bn connecting pipe section; b2b3…b （n-1） Once connected, it becomes the required heat pipe, and the spray lines should be aligned during connection.

[0008] As a preferred technical solution of this application, the electrolyte in S4 contains: Cu2P2O7·3H2O at a concentration of 70 g / L, K4P2O7·3H2O at a concentration of 250 g / L, NH3·H2O at a concentration of 15 ml / L, and gelatin at a concentration of 0.5 g / L; in S4, the electrolysis temperature is 50°C and the electrolysis time is 10 min.

[0009] As a preferred technical solution of this application, the positioning device used in S3 has the following structure: including a heat pipe, a cover plate assembly, a cathode core rod, a transmission assembly, and multiple positioning assemblies. The cover plate assembly includes a cover plate body, an insulating support base, multiple locking blocks, and multiple insulating connecting rods. The multiple insulating connecting rods are fixedly installed between the insulating support base and the cover plate body. The cover plate body is engaged and fixed to the heat pipe through multiple locking blocks and is coaxial. The cathode core is located in the inner cavity of the heat pipe, and the insulating connecting rods and the insulating support base are located on the outer periphery of the cathode core. The transmission assembly includes an annular box and a flywheel gear ring, the flywheel gear ring being movably installed in the inner cavity of the annular box, and the flywheel gear ring being coaxial with the cover plate body; Multiple positioning components are arranged in a ring array between the cover plate body and the ring box. Each positioning component includes a rectangular frame and a top pin. The rectangular frame is fixedly installed between the cover plate body and the ring box. The top pin movably passes through one end of the rectangular frame near the cathode core rod. Multiple top pins are located on the outer wall of the cathode core rod, so that the cathode core rod is coaxial with the cover plate body and the flywheel gear ring.

[0010] Furthermore, the transmission assembly also includes an annular top cover, which is rotatably mounted on the top of the annular box.

[0011] Furthermore, the positioning component also includes: The contact is fixedly installed at one end of the top pin near the cathode core rod; A spring, wherein the spring is located inside the rectangular frame cavity and is sleeved on the outer wall of the top pin.

[0012] Furthermore, the positioning component also includes: A rotating shaft, the top end of which movably passes through the annular box and is movably mounted on the annular upper cover via a bearing, and the bottom end of which is movably mounted on the bottom end of the inner cavity of the rectangular frame via a bearing; The first gear is fixedly mounted on the outer wall of the rotating shaft and meshes with the flywheel ring gear for transmission. The second gear is fixedly mounted on the outer wall of the rotating shaft and is located inside the rectangular frame cavity.

[0013] Furthermore, the positioning component also includes: The T-shaped push plate is located inside the rectangular frame cavity, and the T-shaped push plate is fixedly connected to one end of the top pin located inside the rectangular frame cavity; A rack, one end of which is fixedly connected to a T-shaped push plate, and the other end of which movably passes through a through hole opened on one side of a rectangular frame, and the rack meshes with a second gear for transmission; The guide groove is formed at the bottom of the inner cavity of the rectangular frame, and the bottom end of the T-shaped push plate is movably engaged in the guide groove.

[0014] Furthermore, it also includes: The adjustment assembly includes an adjustment rod, a handwheel, and an adjustment gear. The adjustment rod passes vertically through the annular upper cover and a small bearing is provided between them. The upper end of the adjustment rod is provided with a handwheel, and the lower end of the adjustment rod is fitted with and fixed with an adjustment gear, which meshes with the flywheel raceway.

[0015] Furthermore, in S3, when placing the cathode core rod in the positioning device, the following steps are included: a. The operator rotates the annular top cover and the flywheel gear ring by using the handwheel; When the flywheel ring gear rotates, it meshes with the first gear in multiple positioning components, causing each first gear to rotate synchronously. The first gear drives the second gear located in the inner cavity of the rectangular frame to rotate through the rotating shaft. The second gear then meshes with the rack, converting the rotational motion into the linear motion of the rack. The rack pushes the T-shaped push plate to slide along the guide groove away from the cathode core rod. The T-shaped push plate simultaneously pushes the top pin and the contact fixed at its end to move outward, causing multiple contacts to move away from the center from the outside. b. Then, pass the cathode core rod through the central hole of the cover plate body and place it downwards, so that the cathode core rod is located in the heat pipe cavity and placed on the insulating support base, with the upper end of the cathode core rod extending out from the central hole of the cover plate assembly. Then release the handwheel. Under the action of the spring, the top pins of multiple positioning components move towards the center, so that the ends of multiple top pins abut against the outer cylindrical surface of the upper end of the cathode core rod, thereby pushing the cathode core rod to the center position and achieving strict coaxial centering of the cathode core rod, the cover plate body, and the flywheel gear ring. c. Then, the cover plate assembly is engaged and fixed with the heat pipe by multiple clips, so that the cover plate body and the heat pipe are coaxial. At this time, the cathode core rod is located in the inner cavity of the heat pipe and placed on the insulating support base.

[0016] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. Low cost and good thermal resistance; Specifically, in this scheme: ① A heat pipe is made of copper powder, and the inner wall of the heat pipe is electrolyzed to form a capillary structure using an electrolyte; ② A longer heat pipe is cut into shorter sections, and then a corresponding positioning device is used to ensure that the cathode core is placed accurately at the axial position of the corresponding section, thereby ensuring that the degree of electrolysis on the inner wall of the heat pipe is relatively uniform; ③ Since the heat pipe has been marked, two sections are spliced ​​together to form a connecting section (with the lines aligned) before electrolysis, so that the capillary structure at the end of the section is formed. The structure can be interconnected, which helps to reduce thermal resistance (for example, after b1b2 is electrolyzed together, b2b3 is electrolyzed together, and b3b4 is electrolyzed together, since the upper end of b3 is electrolyzed together with b2 and the lower end of b3 is electrolyzed together with the upper end of b4, then after electrolysis, the capillary structure on the inner wall of the connection end of b2 and b3 has a certain degree of connectivity, and the inner wall of the connection end of b3b4 also has a certain degree of connectivity); ④ This method not only has low cost, but also produces a capillary structure with relatively low thermal resistance. 2. In this invention, multiple positioning components are arranged in a ring array between the cover plate body and the ring box. The flywheel gear ring meshes with multiple first gears simultaneously to drive the racks in each positioning component to synchronously push the T-shaped push plate and the top pin to move centripetally. This enables multiple contacts to synchronously press against the outer wall of the cathode core rod from multiple points in the circumference, automatically pushing the cathode core rod to the center position. This ensures that the cathode core rod, the cover plate body, and the flywheel gear ring are strictly coaxial, effectively improving the centering accuracy and consistency of the cathode core rod during the electrolytic preparation process and ensuring the uniformity of the electrolytic thickness of the capillary structure on the inner wall of the heat pipe.

[0017] 3. In this invention, by setting an adjustment component, the operator only needs to rotate the screw handwheel to drive the flywheel gear ring to rotate through the adjustment gear, thereby synchronously controlling the clamping and loosening of all positioning components on the cathode core rod, making the operation convenient and efficient. At the same time, by utilizing the thread self-locking characteristic between the threaded sleeve and the screw handwheel, the position of the flywheel gear ring can be reliably locked after centering and clamping, effectively preventing the cathode core rod from shifting due to vibration during electrolysis and ensuring the long-term stability of the centering state. In addition, by setting a contact at the end of the top pin, it is possible to avoid indentation damage to the outer wall of the cathode core rod. With the spring sleeved on the outer wall of the top pin, elastic buffering is provided during clamping to prevent rigid jamming. During disassembly, the spring's restoring force pushes the top pin to automatically retract, facilitating quick replacement of the cathode core rod and significantly improving the ease of operation and reliability of the device. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of the method for preparing capillary structures on the inner wall of a heat pipe copper tube proposed in this invention.

[0019] Figure 2 This is a schematic diagram of the cathode core rod and cover plate assembly structure for the method of preparing capillary structures on the inner wall of a copper heat pipe proposed in this invention.

[0020] Figure 3 This is a top view of the cover plate assembly for the method of preparing capillary structures on the inner wall of a heat pipe copper tube proposed in this invention.

[0021] Figure 4 This diagram illustrates the connection between the positioning component and the transmission component in the method for preparing capillary structures on the inner wall of a heat pipe copper tube, as proposed in this invention.

[0022] Figure 5 This is a schematic diagram of the positioning component structure for the method of preparing capillary structures on the inner wall of a heat pipe copper tube proposed in this invention.

[0023] Figure 6 This is a schematic diagram of the adjustment component of the method for preparing capillary structures on the inner wall of a heat pipe copper tube proposed in this invention. Figure 7A schematic diagram of a structure with a rotatable annular top cover.

[0024] Legend: 1. Heat pipe; 2. Cover plate assembly; 201. Cover plate body; 202. Locking block; 203. Insulating support base; 204. Insulating connecting rod; 3. Cathode core rod; 4. Transmission assembly; 401. Annular box; 40101. Inner ring; 40101-1. Annular groove A; 40102. Outer ring; 40102-1. Annular groove B; 402. Annular top cover; 403. Flywheel gear ring; 5. Positioning assembly; 501. Rectangular frame; 502. Top pin; 503. Contact; 504. Spring; 505. Rotating shaft; 506. First gear; 507. Second gear; 508. T-shaped push plate; 509. Rack; 510. Guide groove; 6. Adjustment assembly; 601. Threaded sleeve; 602. Screw handwheel; 603. Adjusting gear. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are merely descriptive and are not intended to limit the scope of protection of the present invention.

[0026] In its specific implementation, such as Figures 1 to 7 The present invention provides a technical solution: A method for preparing capillary structures on the inner wall of a heat pipe made of copper. S1. A heat pipe is fabricated using copper powder. A coating is sprayed along the length of the heat pipe's outer surface to form a spray line. The heat pipe is then cut into sections with a length of 60mm or less and sequentially labeled as b1, b2, b3… up to b… （n-1） bn; S2. Connect the cut ends of b1 and b2 together, align the spray lines, and use an auxiliary connector to make b1 and b2 coaxially connected to form a whole pipe section - called the b1b2 connecting pipe section; S3. A cathode core rod 3 is placed at the axial position of the b1b2 connecting pipe section using a positioning device, and the distance between the outer cylindrical surface of the cathode core rod 3 and the inner wall of the corresponding b1b2 connecting pipe section is consistent. S4. Place the b1b2 connecting pipe section containing the cathode core rod 3 into a tank containing electrolyte, allowing the electrolyte to enter the b1b2 connecting pipe section; connect the cathode core rod 3 to the negative terminal of the power supply, and connect the b1b2 connecting pipe section to the positive terminal, and then perform electrolysis; wherein, the electrolysis temperature is 50℃, and the electrolysis time is 10min (the electrolysis temperature and electrolysis time are just general temperatures and times that can electrolyze copper into a capillary structure). After electrolysis is complete, remove the auxiliary connector; It should be noted that the electrolyte consists of Cu₂P₂O₇·3H₂O at a concentration of 70 g / L, K₄P₂O₇·3H₂O at a concentration of 250 g / L, NH₃·H₂O at a concentration of 15 ml / L, and gelatin at a concentration of 0.5 g / L (for electrolyte preparation, any ordinary electrolyte capable of etching copper into a capillary structure can be used). S5. Referring to steps S2~S4, electrolyze the b2b3 connecting pipe section formed by the butt joint of b2 and b3, and then sequentially electrolyze the b3b4 connecting pipe section, the b4b5 connecting pipe section…b （n-1） Electrolysis is performed on the bn connecting pipe section; b2b3…b （n-1） After passing through the auxiliary connector, you will get the required heat pipe, and the spray lines should be aligned during connection.

[0027] It should be noted that there are various types of auxiliary joints. In the existing technology, any joint that can connect two pipes and seal the connection can be used as an auxiliary joint in this solution.

[0028] The structure of the positioning device will be further explained below.

[0029] It should be noted that the positioning device can ensure the coaxiality of the cathode core rod and the heat pipe, thereby ensuring that all radial distances between the outer cylindrical surface of the cathode core rod and the inner wall of the heat pipe are consistent, thus ensuring that the degree of electrolysis on the inner wall of the heat pipe is consistent, and thus ensuring the quality of the capillary structure of the heat pipe.

[0030] See Figures 1-3 As shown, the positioning device includes a heat pipe 1, a cover plate assembly 2, and a cathode core rod 3. The cover plate assembly 2 includes a cover plate body 201, an insulating support base 203, multiple locking blocks 202, and multiple insulating connecting rods 204. The multiple insulating connecting rods 204 are fixedly installed between the insulating support base 203 and the cover plate body 201. The cover plate body 201 is engaged and fixed to the heat pipe 1 by the multiple locking blocks 202 and is coaxial. The cathode core rod 3 is located in the inner cavity of the heat pipe 1, and the insulating connecting rods 204 and the insulating support base 203 are located on the outer periphery of the cathode core rod 3.

[0031] The assembly relationship between cover plate assembly 2 and heat pipe 1 will be explained below.

[0032] Specifically, by setting up the cover plate assembly 2, the cover plate body 201 is engaged and fixed with the heat pipe 1 by multiple locking blocks 202 and is coaxial, ensuring the coaxiality of the device. By setting up the insulating support base 203, the cathode core rod 3 can be supported.

[0033] like Figure 2 As shown, the card blocks 202 are fixed in a ring array at the bottom of the cover plate body 201, and multiple card blocks 202 are arranged symmetrically in pairs.

[0034] During installation, by arranging multiple locking blocks 202 in a circular array at the bottom of the cover plate body 201 and setting them symmetrically in pairs, the force distribution when the cover plate assembly 2 and the heat pipe 1 are engaged is more uniform. This can effectively prevent the cover plate body 201 from radially deflecting during installation or electrolytic vibration, thereby significantly improving the coaxial positioning accuracy and connection stability between the cover plate body 201 and the heat pipe 1.

[0035] The following is a further explanation of this plan.

[0036] like Figure 3 and Figure 4 As shown, a central hole extending vertically is opened at the center of the cover plate body 201. Multiple positioning components 5 capable of telescopic movement are arranged circumferentially along the central hole on the upper surface of the cover plate body 201. A cathode core rod is placed in the central hole, and the upper end of the cathode core rod can be clamped when the positioning components 5 telescopically move. In addition, a transmission component 4 that enables the positioning components 5 to telescopically move is also provided on the upper surface of each positioning component 5.

[0037] The following section will further explain the structure of the transmission component 4, the structure of the positioning component 5, and the driving relationship between the transmission component and the positioning component.

[0038] (1) First, the structure of the transmission component 4 will be explained.

[0039] like Figure 3 and Figure 4 As shown, the transmission assembly 4 includes an annular box 401 and a flywheel gear ring 403. The annular box 401 includes an inner ring 40101 and an outer ring 40102. The inner ring and the outer ring are coaxially arranged and form an annular gap between them. The flywheel gear ring 403, which can rotate, is sleeved on the inner ring through a corresponding bearing. The annular gap is covered by a rotatable annular cover 402. Furthermore, multiple positioning components 5 are circumferentially fixed on the lower surfaces of the inner ring 40101 and the outer ring 40102, and the positioning components 5 are fixed on the cover plate body 201. In addition, this design was implemented to allow the annular top cover 402 to rotate; see [reference needed]. Figure 7① An inner step is provided at the upper edge of the outer cylindrical surface of the inner ring 40101, and an annular groove A40101-1 is formed on the upper surface of the inner step; a corresponding outer step is also provided at the upper edge of the inner ring wall of the outer ring 40102, and an annular groove B40102-1 is formed on the upper surface of the outer step; the annular cover 402 is circular, and an inner annular groove and an outer annular groove corresponding to the annular grooves A40101-1 and B40102-1 are formed on the lower surface of the annular cover 402; when the annular cover 402 is fastened to the inner and outer steps of the annular gap, a ball is placed between the annular groove A40101-1 and the inner annular groove on the lower surface, and the ring... A ball bearing is also placed between the groove B40102-1 and the outer ring groove on the upper surface; ② An annular outer ring groove is opened on the outer edge of the upper surface of the annular cover 402, and a ball bearing is placed in the outer ring groove. The outer edge of the upper surface of the annular cover 402 is pressed down by an annular outer pressure strip A, and the annular outer pressure strip A is fixed to the outer ring 40102 by spot welding; An annular inner ring groove is opened on the inner edge of the upper surface of the annular cover 402, and a ball bearing is placed in the inner ring groove. The inner edge of the upper surface of the annular cover 402 is pressed down by an annular inner pressure strip A, and the annular inner pressure strip A is fixed to the inner ring 40101 by spot welding; Furthermore, an adjustment component 6 is provided on the annular upper cover 402. The adjustment component 6 can drive the flywheel ring gear 403 to rotate, and when the flywheel ring gear 403 rotates, it can cause multiple positioning components 5 to extend and retract simultaneously; for details, see [reference needed]. Figure 1 , Figure 3 , Figure 6 The adjustment assembly 6 includes an adjustment rod 601, a handwheel 602, and an adjustment gear 603. The adjustment rod 601 passes vertically through the annular upper cover 402 and a small bearing is provided between the two. The handwheel 602 is provided at the upper end of the adjustment rod 601, and the adjustment gear 603 is sleeved and fixed at the lower end of the adjustment rod 601. The adjustment gear 603 meshes with the flywheel pool ring 403.

[0040] (2) The positioning component 5 will be further explained below.

[0041] See Figure 5 (At this time, 502 is in the retracted state and spring 504 is in the stretched state.) The positioning component 5 includes a rectangular frame 501, a top pin 502, and a rack 509. The length of the rectangle 501 is specified to be set along the left and right directions, that is, the two ends of the length are the left end and the right end, respectively; Among them, the upper surface of the rectangular frame 501 has a recessed rectangular cavity (the bottom of the cavity is not penetrated), and there is a guide groove 510 on the bottom surface of the cavity along the left and right direction. One end of the top pin 502 passes through the left wall of the rectangular frame 501 and extends into the rectangular cavity (the top pin 502 can move in the left and right directions), and one end of the rack 509 passes through the right wall of the rectangular frame 501 and extends into the rectangular cavity (the top pin 502 can move in the left and right directions). In the rectangular cavity, the end of the top pin 502 that extends into the rack 509 is connected to the end of the rack 509 through the T-shaped push plate 508. Furthermore, the T-shaped push plate 508 is T-shaped and its lower surface is a raised portion, which is adapted to the guide groove 510 on the bottom surface of the inner cavity of the rectangular frame 501. Furthermore, at the other end (left end) of the top pin 502, there is a contact 503, which has an arcuate groove surface that gradually adapts to the cathode core rod. A spring 504 is fitted on the top pin 502 in the inner cavity of the rectangular frame 501. One end of the spring abuts against the T-shaped push plate 508, and the other end abuts against the left inner wall of the inner cavity. When multiple positioning components 5 are fixed on the upper surface of the cover body 201, the positioning components 5 are arranged radially along the cover body 201, with the left end of the positioning component 5 close to the center hole at the center of the cover body 201 and the right end of the positioning component 5 close to the edge of the cover body 201.

[0042] (3) The driving connection relationship between the positioning component 5 and the transmission component 4 will be explained below.

[0043] See Figure 4 and Figure 5 A rotating shaft 505 is provided on the side wall of the inner cavity of the rectangular frame 501 via an auxiliary lug (not shown in the figure); the rotating shaft 505 is vertically arranged, with a first gear 506 sleeved on its upper end and a second gear 507 sleeved on its lower end. Furthermore, the second gear 507 meshes with the rack 509 in the inner cavity of the rectangular frame 501, and the second gear 506 meshes with the flywheel ring gear 403.

[0044] When the cathode core is mounted at the axial position of the heat pipe using a positioning device: a. The operator rotates the annular upper cover 402 and the flywheel gear ring 403 by using the handwheel 602; When the flywheel ring gear 403 rotates, it simultaneously meshes with the first gear 506 in the multiple positioning components 5, causing each first gear 506 to rotate synchronously. The first gear 506 drives the second gear 507 located in the inner cavity of the rectangular frame 501 to rotate through the rotating shaft 505. The second gear 507 then meshes with the rack 509, converting the rotational motion into the linear motion of the rack 509. The rack 509 pushes the T-shaped push plate 508 to slide along the guide groove 510 away from the cathode core rod 3. The T-shaped push plate 508 simultaneously pushes the top pin 502 and the contact 503 fixed at its end to move outward, causing the multiple contacts 503 to move away from the center to the outside. b. Then, the cathode core rod 3 is passed through the central hole of the cover plate body 201 and placed downwards, so that the cathode core rod 3 is located in the inner cavity of the heat pipe 1 and placed on the insulating support base 203, with the upper end of the cathode core rod 3 extending out from the central hole of the cover plate assembly 2. Then, release the handwheel. Under the action of the spring, the top pins 502 of the multiple positioning components 5 move towards the center, so that the ends of the multiple top pins 502 abut against the outer cylindrical surface of the upper end of the cathode core rod, thereby pushing the cathode core rod 3 to the center position and achieving strict coaxial centering of the cathode core rod 3 with the cover plate body 201 and the flywheel gear ring 403. c. Then, the cover plate assembly 2 is engaged and fixed with the heat pipe 1 by multiple locking blocks 202, so that the cover plate body 201 and the heat pipe 1 remain coaxial. At this time, the cathode core rod 3 is located in the inner cavity of the heat pipe 1 and placed on the insulating support base 203.

[0045] It should be noted that in this plan: (1) The design and structure of the contact 503 can effectively increase the contact area and avoid the end of the top pin 502 from causing local indentation or damage to the outer wall of the cathode core rod 3. (2) Through the meshing transmission between the first gear 506 and the flywheel ring gear 403, the circumferential rotation of the flywheel ring gear 403 is synchronously transmitted to the rotating shaft 505. Then, through the second gear 507 located in the inner cavity of the rectangular frame 501, the power is transmitted downward, realizing the effect of driving multiple positioning components 5 in a single circumferential input, ensuring the synchronicity and consistency of the actions of all positioning components 5. At the same time, the two ends of the rotating shaft 505 are respectively mounted on the annular cover 402 and the rectangular frame 501 through bearings, ensuring the rotational accuracy and transmission stability of the rotating shaft 505. (3) The guide groove 510 at the bottom of the inner cavity of the rectangular frame 501 slides and guides the bottom of the T-shaped push plate 508, effectively restricting the degree of freedom of the T-shaped push plate 508, ensuring that the top pin 502 can only make linear translation along the radial direction, avoiding the top pin 502 from swinging or getting stuck during the movement, and greatly improving the sensitivity and positioning accuracy of the centering adjustment. (4) By setting multiple positioning components 5 in a ring array between the cover plate body 201 and the ring box 401, and by using the top pin 502 that moves through the rectangular frame 501 to synchronously abut against the outer wall of the cathode core rod 3 from multiple points in the circumference, a uniform radial clamping force can be applied to the cathode core rod 3, thereby realizing the automatic centering of the cathode core rod 3 and ensuring that the cathode core rod 3 always maintains strict coaxiality with the cover plate body 201 and the flywheel gear ring 403 throughout the entire electrolytic preparation process, thus ensuring that the electrolytic thickness of the capillary structure on the inner wall of the heat pipe 1 is uniform.

[0046] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A method for preparing capillary structures on the inner wall of a heat pipe made of copper, characterized in that, S1. A heat pipe is fabricated using copper powder. A coating is sprayed along the length of the heat pipe's outer surface to form a spray line. The heat pipe is then cut into sections with a length of 60mm or less and sequentially labeled as b1, b2, b3… up to b… （n-1） bn; S2. Connect the cut ends of b1 and b2 together, align the spray lines, and use an auxiliary connector to make b1 and b2 coaxially connected to form a whole pipe section - called the b1b2 connecting pipe section; S3. A cathode core rod (3) is placed at the axial position of the b1b2 connecting pipe section using a positioning device, and the distance between the outer cylindrical surface of the cathode core rod (3) and the inner wall of the corresponding b1b2 connecting pipe section is consistent. S4. Place the b1b2 connecting pipe section containing the cathode core rod (3) into the tank containing the electrolyte, so that the electrolyte can enter the b1b2 connecting pipe section; connect the cathode core rod (3) to the negative terminal of the power supply, connect the b1b2 connecting pipe section to the positive terminal, and then perform electrolysis. After electrolysis is complete, remove the auxiliary connector; S5. Referring to steps S2~S4, electrolyze the b2b3 connecting pipe section formed by the butt joint of b2 and b3, and then sequentially electrolyze the b3b4 connecting pipe section, the b4b5 connecting pipe section…b （n-1） Electrolysis is performed on the bn connecting pipe section; b2b3…b （n-1） Once connected, it becomes the required heat pipe, and the spray lines should be aligned during connection.

2. The method for preparing capillary structures on the inner wall of a heat pipe copper tube according to claim 1, characterized in that, In the electrolyte of S4: The 1L electrolyte contains Cu2P2O7·3H2O at a concentration of 70g / L, K4P2O7·3H2O at a concentration of 250g / L, NH3·H2O at a concentration of 15ml / L, and gelatin at a concentration of 0.5g / L. In S4, the electrolysis temperature is 50℃ and the electrolysis time is 10min.

3. The method for preparing capillary structures on the inner wall of a heat pipe copper tube according to claim 1, characterized in that, The positioning device used in S3 has the following structure: It includes a heat pipe (1), a cover plate assembly (2), a cathode core rod (3), a transmission assembly (4), and multiple positioning assemblies (5); The cover plate assembly (2) includes a cover plate body (201), an insulating support base (203), multiple locking blocks (202) and multiple insulating connecting rods (204), and the multiple insulating connecting rods (204) are fixedly installed between the insulating support base (203) and the cover plate body (201). The cover plate body (201) is engaged and fixed with the heat pipe (1) through multiple locking blocks (202) and is coaxial. The cathode core rod (3) is located in the inner cavity of the heat pipe (1), and the insulating connecting rods (204) and the insulating support base (203) are located on the outer periphery of the cathode core rod (3). The transmission assembly (4) includes an annular box (401) and a flywheel gear ring (403). The flywheel gear ring (403) is movably installed in the inner cavity of the annular box (401), and the flywheel gear ring (403) is coaxial with the cover plate body (201). Multiple positioning components (5) are arranged in a ring array between the cover plate body (201) and the ring box (401). Each positioning component (5) includes a rectangular frame (501) and a top pin (502). The rectangular frame (501) is fixedly installed between the cover plate body (201) and the ring box (401). The top pin (502) movably passes through the rectangular frame (501) near one end of the cathode core rod (3). Multiple top pins (502) are located on the outer wall of the cathode core rod (3), so that the cathode core rod (3) is coaxial with the cover plate body (201) and the flywheel gear ring (403).

4. The method for preparing capillary structures on the inner wall of a heat pipe copper tube according to claim 3, characterized in that, The transmission assembly (4) also includes: An annular top cover (402) is rotatably mounted on the top of the annular box (401).

5. The method for preparing capillary structures on the inner wall of a heat pipe copper tube according to claim 4, characterized in that, The positioning component (5) further includes: Contact (503), said contact (503) is fixedly installed on one end of the top pin (502) near the cathode core rod (3); Spring (504) is located in the inner cavity of the rectangular frame (501) and is sleeved on the outer wall of the top pin (502).

6. The method for preparing capillary structures on the inner wall of a heat pipe copper tube according to claim 5, characterized in that, The positioning component (5) further includes: A rotating shaft (505) has its top end movably passing through an annular box (401) and movably mounted on an annular upper cover (402) via a bearing. The bottom end of the rotating shaft (505) is movably mounted on the bottom end of the inner cavity of a rectangular frame (501) via a bearing. The first gear (506) is fixedly installed on the outer wall of the rotating shaft (505), and the first gear (506) meshes with the flywheel ring gear (403) for transmission; The second gear (507) is fixedly installed on the outer wall of the rotating shaft (505) and is located in the inner cavity of the rectangular frame (501).

7. The method for preparing capillary structures on the inner wall of a heat pipe copper tube according to claim 5, characterized in that, The positioning component (5) further includes: T-shaped push plate (508), the T-shaped push plate (508) is located in the inner cavity of the rectangular frame (501), and the T-shaped push plate (508) is fixedly connected to one end of the top pin (502) located in the inner cavity of the rectangular frame (501); A rack (509) is fixedly connected at one end to a T-shaped push plate (508), and the other end of the rack (509) is movably inserted through a through hole opened on one side of a rectangular frame (501). The rack (509) meshes with a second gear (507) for transmission. The guide groove (510) is located at the bottom of the inner cavity of the rectangular frame (501), and the bottom end of the T-shaped push plate (508) is movably engaged in the guide groove (510).

8. The method for preparing capillary structures on the inner wall of a heat pipe copper tube according to claim 7, characterized in that, Also includes: Adjustment assembly (6), the adjustment assembly (6) includes adjustment rod (601), handwheel (602) and adjustment gear (603). The adjustment rod (601) passes vertically through the annular cover (402) and a small bearing is provided between the two. The handwheel (602) is provided at the upper end of the adjustment rod (601), and the adjustment gear (603) is sleeved and fixed at the lower end of the adjustment rod (601). The adjustment gear (603) meshes with the flywheel pool ring (403).

9. The method for preparing capillary structures on the inner wall of a heat pipe copper tube according to claim 8, characterized in that, In S3, when placing the cathode core rod in the positioning device, the following steps are included: a. The operator rotates the annular top cover and the flywheel gear ring by using the handwheel; When the flywheel ring gear rotates, it meshes with the first gear in multiple positioning components, causing each first gear to rotate synchronously. The first gear drives the second gear located in the inner cavity of the rectangular frame to rotate through the rotating shaft. The second gear then meshes with the rack, converting the rotational motion into the linear motion of the rack. The rack pushes the T-shaped push plate to slide along the guide groove away from the cathode core rod. The T-shaped push plate simultaneously pushes the top pin and the contact fixed at its end to move outward, causing multiple contacts to move away from the center from the outside. b. Then, pass the cathode core rod through the central hole of the cover plate body and place it downwards, so that the cathode core rod is located in the heat pipe cavity and placed on the insulating support base, with the upper end of the cathode core rod extending out from the central hole of the cover plate assembly. Then release the handwheel. Under the action of the spring, the top pins of multiple positioning components move towards the center, so that the ends of multiple top pins abut against the outer cylindrical surface of the upper end of the cathode core rod, thereby pushing the cathode core rod to the center position and achieving strict coaxial centering of the cathode core rod, the cover plate body, and the flywheel gear ring. c. Then, the cover plate assembly is engaged and fixed with the heat pipe by multiple clips, so that the cover plate body and the heat pipe are coaxial. At this time, the cathode core is located in the inner cavity of the heat pipe and placed on the insulating support base.

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