Self-excited vibration heat pipe

Abstract

This self-excited vibration heat pipe (1) comprises: a working fluid flow path (2) which is provided inside a metal heat pipe body (10) and in which a working fluid is sealed; a heating unit (H) for applying heat from the outside of the heat pipe body (10) to the working fluid; and a heat dissipation unit (C) for dissipating the heat of the working fluid to the outside. The working fluid transports heat while moving between the heating unit (H) and the heat dissipation unit (C). The heat pipe body (10) is composed of a laminate including a plurality of metal plates (3), has a groove part (31) constituting the working fluid flow path (2) in a butting part (30) of the plurality of metal plates (3), and has a joint part (5) for hermetically sealing the working fluid flow path (2). The metal plate (3) has a protective coating (4) that covers at least a surface serving as a flow path wall (21) of the working fluid flow path (2).

Description

Self-excited vibration heat pipe Cross-reference to related applications

[0001] This application is based on Patent Application No. 2024-191278 filed on October 31, 2024, the content of which is incorporated herein by reference.

[0002] This disclosure relates to a self-excited vibration heat pipe.

[0003] For example, in various devices for vehicles or industries, a self-excited vibration heat pipe is used to cool heat sources such as electronic devices, motors, and batteries. The self-excited vibration heat pipe arranges a working fluid flow path filled with a working fluid between the high-temperature part and the low-temperature part of the device, so that a gas phase part and a liquid phase part are alternately formed in the working fluid, generating self-excited vibrations to perform heat transport.

[0004] Since a cooling device using a self-excited vibration heat pipe is expected to be small and have high heat transport performance, various proposals have been made regarding the specific channel shape, constituent material of the working fluid flow path, selection of the working fluid, filling method, etc. For example, Patent Document 1 discloses an aluminum heat pipe with a water-repellent treatment on the inner surface of a channel formed by alternately folding back, and the filling rate of the working fluid is 30% by volume or less. At this time, an extremely short and small-volume liquid slug (bridge) is formed in the channel, resulting in a heat transport phenomenon different from the conventional type (self-regenerating bridge type), and it is said that vibrations and flows are likely to occur.

[0005] In the self-regenerating bridge type heat pipe described in Patent Document 1, the working fluid flow path consists of, for example, a flat multi-hole pipe provided in an aluminum block, and is filled with, for example, distilled water as the working fluid. The internal channels of the multi-hole pipe are alternately cut at both end faces to form alternately folded and continuous channels. The openings of the folded parts are sealed with a resin adhesive, for example, after clamping both end faces under pressure.

[0006] International Publication No. 2023 / 157536

[0007] Generally, it is known that the heat transport performance of a heat pipe improves as the number of reversing flow channels increases. As described in Patent Document 1, in a configuration in which a multi-hole tube is provided in a metal block, the smaller the cross-sectional area of ​​the flow channels in the multi-hole tube, the more flow channels can be provided, and the longer the total flow channel length becomes. On the other hand, from a manufacturing perspective, as the number of flow channels increases or each flow channel becomes longer, it becomes more difficult to manufacture molds for extruding the multi-hole tube, for example. Also, when performing surface treatment on the flow channels, it becomes difficult to flow the treatment solution into the tube, making it easier to hinder the formation of a uniform coating. In that case, there is a concern that the corrosion resistance may decrease due to contact between the working fluid and the exposed surface.

[0008] The purpose of this disclosure is to provide a self-excited vibrating heat pipe that can achieve both improved heat transport performance through the working fluid flow path and improved manufacturability.

[0009] One aspect of the present disclosure is a self-excited vibrating heat pipe comprising: a working fluid channel provided inside a metal heat pipe body and containing a working fluid; a heating section for supplying heat from outside the heat pipe body to the working fluid; and a heat dissipation section for releasing heat from the working fluid to the outside, wherein the working fluid transports heat by moving between the heating section and the heat dissipation section in the working fluid channel, the heat pipe body being made of a laminate including a plurality of metal plates, having grooves constituting the working fluid channel at the abutment portions of two adjacent metal plates in the lamination direction, and having joints for sealing the working fluid channel, and the metal plates having a protective coating covering at least the surface that forms the channel wall of the working fluid channel.

[0010] In the self-oscillating heat pipe with the above configuration, the heat pipe body, which is provided with the working fluid passage, is made of a laminate of multiple metal plates stacked on top of each other. For example, by providing grooves corresponding to the shape of the passage on one or both of two adjacent metal plates separated by a joint and stacking them, a working fluid passage of a desired shape can be formed. Alternatively, a laminate of three or more metal plates can be used, and the grooves formed at each joint can be connected to form the working fluid passage. In this case, by performing surface treatment on the plate surfaces that will become the joints beforehand, a uniform protective coating can be formed, and then the plate surfaces excluding the grooves can be joined together. As a result, the working fluid passage is sealed by being surrounded by the joints provided between the plate surfaces of the joints. Therefore, it becomes possible to reduce the cross-sectional area of ​​the working fluid passage or increase the length of the passage while suppressing the reduction in corrosion resistance due to contact with the working fluid.

[0011] As described above, according to the above embodiment, it is possible to provide a self-excited vibrating heat pipe that can achieve both improved heat transport performance through the working fluid flow path and improved manufacturability.

[0012] The above-mentioned objectives and other objectives, features and advantages of this disclosure will become clearer with reference to the attached drawings and the detailed description below. The drawings are as follows: Figure 1 is a perspective view showing the main components of the heat pipe body constituting the self-excited vibrating heat pipe in Embodiment 1, and is a cross-sectional view taken along line I-I in Figure 2; Figure 2 is a perspective view showing the schematic configuration of the self-excited vibrating heat pipe in Embodiment 1; Figure 3 is a diagram showing the main components of the self-excited vibrating heat pipe in Embodiment 1, and is a view taken along arrows A and B in Figure 1; Figure 4 is an enlarged cross-sectional view showing the main components of the self-excited vibrating heat pipe in Embodiment 1; and Figure 5 shows a modified example of the self-excited vibrating heat pipe in Embodiment 1. Figure 6 is an enlarged cross-sectional view showing the main components of the self-excited vibrating heat pipe in Embodiment 2, Figure 7 is a diagram showing the main components of the self-excited vibrating heat pipe in Embodiment 2, and is a view taken along arrows C and D in Figure 6, Figure 8 is an enlarged cross-sectional view showing the main components of the self-excited vibrating heat pipe in Embodiment 3, Figure 9 is a diagram showing the joining process of the metal plates constituting the main part of the self-excited vibrating heat pipe in Embodiment 3, and is an enlarged perspective view of the main part, Figure 10 is a self-excited vibrating heat pipe in Test Example 1 Figure 11 is a plan view showing the configuration of the metal plates forming the heat pipe and the flow path shape; Figure 12 is a schematic diagram illustrating the manufacturing method of the self-excited vibrating heat pipe in Test Example 1; Figure 13 is an enlarged cross-sectional view showing the main components of the self-excited vibrating heat pipe in Embodiment 4; Figure 14 is an enlarged cross-sectional view showing the main components of the self-excited vibrating heat pipe in a modified example of Embodiment 4; Figure 15 is a self-excited vibrating heat pipe in Embodiment 5. Figure 16 is a perspective view showing the schematic configuration of the pipe, Figure 17 is an enlarged cross-section showing the laminated structure of the self-excited vibrating heat pipe in Embodiment 5, and is a cross-sectional view along lines E-E and F-F in Figure 15, Figure 18 is a schematic diagram showing the schematic configuration and main components of the self-excited vibrating heat pipe in Embodiment 6, Figure 19 is a schematic diagram showing the schematic configuration and main components of the self-excited vibrating heat pipe in a modified example of Embodiment 6, and Figure 20 is...Figure 21 is a perspective view showing the schematic configuration of the self-excited vibrating heat pipe in Embodiment 7, and Figure 21 is a perspective view showing the schematic configuration of the self-excited vibrating heat pipe in a modified example of Embodiment 7.

[0013] (Embodiment 1) Embodiment 1 relating to a self-excited vibrating heat pipe will be described with reference to Figures 1 to 4. As shown in Figures 1 and 2, the self-excited vibrating heat pipe 1 of this embodiment has a metal heat pipe body 10, a heating section H and a heat dissipation section C. The heat pipe body 10 is equipped with a working fluid passage 2 inside which a working fluid is sealed, and is configured as a self-excited vibrating heat pipe in which the working fluid moves between the heating section H and the heat dissipation section C in the working fluid passage 2 to transport heat.

[0014] In the self-excited vibrating heat pipe 1, the heating section H is the part that transfers heat from outside the heat pipe body 10 to the working fluid. The heat dissipation section C is the part that releases heat from the working fluid to the outside of the heat pipe body 10. The heating section H and the heat dissipation section C are, for example, the high-temperature and low-temperature parts of the device in which the self-excited vibrating heat pipe 1 is installed, and can be set appropriately according to the device configuration.

[0015] The heat pipe body 10 consists of a laminate containing a plurality of metal plates 3. The laminate has grooves 31 that constitute the working fluid channel 2 at the abutment portions 30 of two adjacent metal plates 3 in the lamination direction (Y direction shown in Figure 1), and also has joint portions 5 that seal the working fluid channel 2. The metal plates 3 that make up the laminate have a protective coating 4 that covers at least the surface that becomes the channel wall 21 of the working fluid channel 2.

[0016] Specifically, at least one of the two adjacent metal plates 3 is provided with a groove 31. For example, a metal heat pipe body 10 may have two metal plates 3, namely a first metal plate 3A and a second metal plate 3B. In this case, one or both of the first metal plate 3A and the second metal plate 3B are provided with a groove 31 that constitutes the flow path wall 21 of the working fluid flow path 2. The groove 31 can have a meandering flow path shape that folds back and forth between the heating section H and the heat dissipation section C.

[0017] This embodiment shows a configuration in which grooves 31 are present on both of the two metal plates 3. The metal material constituting the heat pipe body 10 is not necessarily limited, but for example, from the viewpoint of processability and thermal conductivity, materials including aluminum, copper, or alloys thereof can be used. The protective coating 4 protects the surface of the metal plate 3 from being exposed to the working fluid passage 2 and coming into contact with the working fluid.

[0018] The working fluid can be any fluid capable of heat transport, which evaporates upon receiving heat in the heating section H, condenses upon releasing heat in the heat dissipation section C, and generates self-excited vibrations due to pressure fluctuations, etc. As such a working fluid, for example, water, alcohol such as ethanol, or solutions containing them can be used.

[0019] In Figure 2, one of the directions along one side of the rectangular metal plate 3, which is the flow direction of the working fluid channel 2 (i.e., the direction indicated by the arrow in Figure 2), will hereafter be referred to as the X direction. The other direction along one side, which is perpendicular to the X direction, will be referred to as the Z direction. The Y direction shown in Figure 1 is perpendicular to the X and Z directions, and is the lamination direction of the laminate, as well as the thickness direction of the first metal plate 3A and the second metal plate 3B.

[0020] The joint 5 includes, for example, a resin bonding layer 51 interposed between the first metal plate 3A and the second metal plate 3B. The resin bonding layer 51 is made of a bonding material containing, for example, a curable resin composition. By using such a bonding material, good bonding performance can be obtained even in a configuration in which protective coatings 4 are present on the surfaces of the first metal plate 3A and the second metal plate 3B, and the sealing performance of the working fluid channel 2 can be ensured.

[0021] In this configuration, two grooves 31 provided in the two metal plates 3 form a working fluid channel 2 at the abutment portion 30 of the two metal plates 3. This makes it easier to process the metal plates 3 to form the grooves 31 and to perform subsequent surface treatment. The working fluid channel 2 can be sealed by joining the plate surfaces with the protective coating 4 formed on them using a resin bonding layer 51. Therefore, it is possible to achieve the desired channel configuration while ensuring the corrosion resistance of the heat pipe body 10, and to achieve both good heat transport performance and manufacturability.

[0022] Next, the configuration of each part of the self-excited vibrating heat pipe 1 will be described in detail. The self-excited vibrating heat pipe 1 can be used in various devices, such as those for vehicles or industrial use, to constitute a cooling device for cooling the heat-generating parts of the device. In that case, for example, as shown in Figure 2, the heat-generating part of the device can be used as the heat source for the heating section H, and the low-temperature part of the device can be used as the cooling source for the heat-dissipating section C, with the heat pipe body 10 placed between them.

[0023] In this configuration, the working fluid passage 2 provided in the heat pipe body 10 consists of parallel straight sections 22 connected alternately via folded sections 23, forming a continuous meandering passage. The heating section H and the heat dissipation section C are located at both ends of the heat pipe body 10 in the X direction, which is the direction of the working fluid passage 2 and the direction in which the straight sections 22 extend. As a result, the working fluid in the working fluid passage 2 flows repeatedly back and forth between the heating section H and the heat dissipation section C via the folded sections 23.

[0024] (Heat pipe body 10) In Figure 1, the heat pipe body 10 consists of a laminate formed by stacking multiple metal plates 3. Specifically, the laminate has a two-layer structure including a first metal plate 3A and a second metal plate 3B, and a working fluid channel 2 is provided inside it. The first metal plate 3A and the second metal plate 3B each have a groove portion 31 on the side that forms the abutment portion 30 of the laminate, which becomes part of the channel wall 21 of the working fluid channel 2. That is, the first metal plate 3A is provided with a first groove portion 31A which becomes the first wall portion 21A, and the second metal plate 3B is provided with a second groove portion 31B which becomes the second wall portion 21B, and they are arranged opposite each other with the abutment portion 30 as the opening side. As a result, the openings of both groove portions 31 are closed, and a channel wall 21 is formed in which the first wall portion 21A and the second wall portion 21B are integrated.

[0025] As schematically shown in Figure 3, the first metal plate 3A and the second metal plate 3B are made of the same rectangular plate material, and the first groove 31A or the second groove 31B, which constitute the first wall portion 21A or the second wall portion 21B of the working fluid passage 2, are provided at the same position on the plate surface. The first groove 31A and the second groove 31B are meandering grooves of the same shape, and the grooves that become the straight portion 22 of the working fluid passage 2 extend in the X direction, and multiple grooves are arranged in parallel in the Z direction. In addition, multiple grooves that become the folded portion 23 of the working fluid passage 2 are provided at both ends in the X direction, connecting adjacent straight grooves in an alternating manner.

[0026] In the first metal plate 3A or the second metal plate 3B, the surface on which the first groove 31A or the second groove 31B is not formed becomes an abutment surface that is joined via the joint 5 (see, for example, Figure 1) when the abutment portion 30 is formed. Prior to joining, a protective coating 4 (see, for example, Figure 1) is formed on the surface of the first metal plate 3A or the second metal plate 3B.

[0027] As a result, the first metal plate 3A and the second metal plate 3B are configured as a pair of flow path plates, each having a groove 31, and the heat pipe body 10 has a symmetrical mechanism in the Y direction with respect to the abutment portion 30. In this case, for example, the warping that occurs in the high-temperature portion is also symmetrical in the lamination direction, which has the advantage of being able to relieve stress.

[0028] Although the heat pipe body 10 shown in Figures 2 and 3 is shown as having a roughly square shape as an example, it may have other shapes such as a rectangle. For example, since the length of the heat pipe body 10 in the X direction corresponds to the distance between the heating section H and the heat dissipation section C, the shape of the heat pipe body 10 can be appropriately set according to the arrangement of the heating section H and the heat dissipation section C in the device to which the self-excited vibrating heat pipe 1 is applied.

[0029] As shown in an enlarged view in Figure 4, in this embodiment, the working fluid channel 2 has a rectangular cross-sectional shape. Here, for example, it is a rectangular cross-sectional shape that is elongated vertically (Y-direction length > Z-direction length) with respect to the stacking direction of the heat pipe body 10, but it is not limited to this, and may be a horizontally elongated rectangle or a square. The first groove 31A and the second groove 31B consist of rectangular recessed grooves and correspond to the first wall portion 21A and the second wall portion 21B, which are half of the channel wall 21, respectively, forming a horizontally elongated rectangular space (Z-direction length > Y-direction length) that divides the working fluid channel 2 in two.

[0030] The first metal plate 3A and the second metal plate 3B have a protective coating 4 on their entire surfaces on the side that forms the abutting portion 30. That is, the protective coating 4 is formed to cover the inner surfaces of the first groove portion 31A and the second groove portion 31B and the abutting surfaces that continue from their openings. As a result, the entire flow path wall 21 of the working fluid flow path 2 is covered with the protective coating 4. Furthermore, at the abutting portion 30, the protective coatings 4 formed on the abutting surfaces of the first metal plate 3A and the second metal plate 3B are joined together via a joint portion 5.

[0031] The protective coating 4 has the function of protecting the metal surface constituting the heat pipe body 10 from being exposed to the working fluid flow path 2, and can be, for example, a surface treatment film. Specifically, when the heat pipe body 10 is made of an aluminum metal plate 3, it can be an anodized coating film or a boehmite coating film. The anodized coating film consists of anodized aluminum oxide produced by anodic oxidation, and the boehmite coating film consists of boehmite monohydrated aluminum oxide produced by hydration treatment with high-temperature steam.

[0032] Alternatively, the protective coating 4 may be a plated film, specifically a metal plating film such as Zn plating, Ni plating, Cu plating, or Au plating. In either case, the protective coating 4 only needs to cover at least the flow path wall 21 of the working fluid flow path 2, but generally, as shown in Figure 4, the protective coating 4 can be formed over the entire exposed surface.

[0033] Thus, the heat pipe body 10 is constructed by joining a first metal plate 3A and a second metal plate 3B, which facilitates the formation of a protective coating 4 on each metal plate 3. Specifically, when the protective coating 4 is formed by pre-treatment or plating, the treatment solution can be easily flowed into the groove 31 which becomes the working fluid channel 2, enabling the formation of a uniform coating. Subsequently, by joining the two metal plates 3, the working fluid channel 2 is formed, and its surface is uniformly covered with the protective coating 4, thereby suppressing the reduction in corrosion resistance due to contact between the working fluid and the channel wall 21.

[0034] In this embodiment, the resin bonding layer 51 that forms the joint 5 is made of a bonding material including, for example, a curable resin composition. The curable resin composition can be any resin composition that hardens upon exposure to heat or light to form a three-dimensional crosslinked structure and is stable in the usage environment. Specifically, it is desirable that the composition has a glass transition temperature (Tg) of 100°C or higher, does not soften within the usage temperature range, the cured product does not melt at a heated state of about 150°C, and is insoluble in common solvents such as water, alcohol, and acetone.

[0035] Examples of such curable resin compositions include epoxy resins, polyurethane resins, polyacrylic resins, unsaturated polyester resins, phenolic resins, bismaleimide resins, and cyanate resins. Preferably, epoxy resins or polyacrylic resins are used, and more preferably, epoxy resins are used. Epoxy resins, which are liquid at room temperature, have excellent coating workability and, after curing, excellent chemical resistance to water and other solvents, as well as excellent adhesion to various materials such as metals, their oxides, or resins. Therefore, they can be suitably used for joining metals via a protective film 4. Furthermore, epoxy resins have excellent heat resistance, and high-Tg epoxy resins with a higher glass transition temperature (for example, Tg ≥ 125°C) can be used, which can improve the reliability of the joint 5 at high temperatures.

[0036] The bonding material can be a composite resin material obtained by further blending an amorphous thermoplastic resin composition with a curable resin composition such as epoxy resin. Examples of amorphous thermoplastic resin compositions include polyethersulfone (PES) and polyphenylene oxide (PPO), which improve the adhesive strength at the joint 5. When using such a composite resin as the bonding material, the blending ratio (mass ratio) of the curable resin composition to the amorphous thermoplastic resin composition can be, for example, in the range of 97:3 to 30:70. Preferably, the blending ratio of the curable resin composition to the amorphous thermoplastic resin composition should be appropriately selected in the range of 90:10 to 40:60 to obtain the desired adhesion.

[0037] The filling rate of the working fluid in the working fluid channel 2 is not necessarily limited; for example, if the working fluid is water, it can be appropriately set within a range of 80 volume% or less. Preferably, the filling rate of the working fluid is 60 volume% or less to further reduce thermal resistance. More preferably, the filling rate can be selected within a range of 5 volume% to 50 volume% so that the desired effect of reducing thermal resistance is obtained in the combination of the metal material constituting the metal plate 3 and the working fluid.

[0038] Thus, according to this embodiment, the heat pipe body 10 constituting the self-excited vibrating heat pipe 1 consists of a first metal plate 3A and a second metal plate 3B, and the abutting surfaces, each having a protective coating 4 formed on its entire surface, are joined by a resin bonding layer 51 to form a working fluid channel 2. As a result, a channel wall 21 is formed in which the symmetrical first wall portion 21A and the second wall portion 21B are integrated, sealing it airtight and liquidtight, and the surface of the channel wall 21 is protected by the protective coating 4. Therefore, it is possible to miniaturize the heat pipe body 10 while ensuring corrosion resistance, and to realize a self-excited vibrating heat pipe 1 that achieves both good heat transport performance and improved manufacturability.

[0039] (Embodiment 2) Embodiment 2 relating to a self-excited vibrating heat pipe will be described with reference to Figures 5 to 7. In Embodiment 1 described above, the first metal plate 3A and the second metal plate 3B constituting the heat pipe body 10 were a pair of flow path plates, both of which were provided with grooves 31 that serve as working fluid flow paths 2. In this embodiment, however, one of the first metal plate 3A and the second metal plate 3B is a flow path plate, and the other is a cover plate. The basic configuration of the self-excited vibrating heat pipe 1 is the same as in Embodiment 1, and the differences will be described below. Note that, among the reference numerals used in Embodiment 2 and later, those that are the same as those used in the previously described embodiments represent the same components as in the previously described embodiments unless otherwise specified.

[0040] As shown in Figure 5, in this embodiment as well, the heat pipe body 10 is configured as a laminated body with a two-layer structure including a first metal plate 3A and a second metal plate 3B. As shown in Figure 6, the laminated bodies are joined via a joint 5, and inside it, a working fluid passage 2 is formed by a groove 31 provided in the second metal plate 3B and a part of the surface of the first metal plate 3A that closes the opening of the groove 31. That is, a part of the surface of the first metal plate 3A that becomes the first wall 21A and the groove 31 that becomes the second wall 21B form the passage wall 21 of the working fluid passage 2, and a protective coating 4 is provided over its entire surface.

[0041] As schematically shown in Figures 6 and 7, in this embodiment, the groove 31 is not provided on the side of the first metal plate 3A that will become the abutting surface, and the plate surface of the second metal plate 3B in the portion corresponding to the groove 31 becomes the first wall portion 21A. The cross-sectional shape of the working fluid flow path 2 is a horizontally elongated rectangular shape (Z direction length > Y direction length) corresponding to the groove 31 of the second metal plate 3B. In this case as well, on the side of the abutting portion 30, after a protective coating 4 is formed on the entire exposed surface of the first metal plate 3A and the second metal plate 3B, the abutting surfaces can be joined together via the resin bonding layer 51.

[0042] Thus, the heat pipe body 10 may be constructed in a laminated structure in which one of the first metal plate 3A and the second metal plate 3B has a groove 31. This simplifies manufacturing as the groove 31 is only processed on one side, and the same effects as in Embodiment 1 can be obtained with a relatively simple configuration.

[0043] In that case, the first metal plate 3A and the second metal plate 3B can be made of different materials, or a surface texture can be formed on one of the surfaces. For example, from the viewpoints of improving the workability of the groove portion 31, the joining property of the joining portion 5, further imparting capillary force, and improving corrosion resistance, the first metal plate 3A and the second metal plate 3B can be selected respectively. Examples of the surface texture include alumina nanowires or copper nanowires, etc. For example, it can be integrally provided on the outer surface of the first metal plate 3A (the plate surface on the opposite side of the joining portion 5 in the Y direction) to improve the thermal conductivity.

[0044] Also, by changing the plate thicknesses of the first metal plate 3A and the second metal plate 3B, the plate thickness of the second metal plate 3B in which the groove portion 31 is formed can be made thicker, or the plate thickness of the first metal plate 3A in which the groove portion 31 is not formed can be made thinner so as to ensure a desired flow path cross-sectional area and flow path length. In this embodiment, the groove portion 31 is provided in the second metal plate 3B, but this is for convenience, and a configuration in which the groove portion 31 is provided in the first metal plate 3A may also be used. The arrangement and shape of the groove portion 31 are not limited to those shown, and can be appropriately changed so as to obtain desired performance.

[0045] (Embodiment 3) An embodiment 3 related to a self-excited vibration heat pipe will be described with reference to FIGS. 8 to 9. In the above embodiment, the joining portion 5 of the heat pipe body 10 is a resin joining layer 51 and is joined through the protective film 4, but in this embodiment, the first metal plate 3A and the second metal plate 3B are joined at the joining portion 5 by a metal joining layer 52 or direct joining without passing through the protective film 4. The basic configuration of the other self-excited vibration heat pipe 1 is the same as that of the above embodiment 1, and hereinafter, the differences will be mainly described.

[0046] As shown in FIG. 8, also in this embodiment, at the butting portion 30 of the heat pipe body 10, the configuration in which the flow path wall 21 of the working fluid flow path 2 has the protective film 4 is the same, and the first metal plate 3A and the second metal plate 3B are pre-treated with surface treatment or the like to form the protective film 4. Then, the first metal plate 3A and the second metal plate 3B can be joined by adopting a method of removing or removing the protective film 4 on the surface that becomes the butting surface while joining.

[0047] The metal bonding layer 52 can be, for example, an ultrasonic solder layer formed by ultrasonic soldering. Ultrasonic soldering is a method of removing the oxide film on the metal surface by cavitation generated by ultrasonic waves and forming an alloy layer as the ultrasonic solder layer through diffusion bonding between the activated metal surface and the solder. According to this method, bonding can be achieved at a lower temperature compared to general brazing that requires high-temperature treatment, and since there is no need to remove the protective film 4, the number of processes required for bonding can be reduced.

[0048] Also, as shown in FIG. 9, a method of removing the protective film 4 in advance before bonding can be adopted. In that case, as shown in FIG. 9 (upper figure), for the second metal plate 3B having the protective film 4 on its surface, the uppermost protective film 4 at the butting portion 30 is removed by polishing or the like, and as shown in FIG. 9 (lower figure), the surface serving as the butting surface can be exposed. For the first metal plate 3A not shown, the same treatment of removing the protective film 4 at the corresponding part is performed, and then the exposed surfaces can be bonded by pressure bonding or diffusion bonding at a temperature below the melting point to form the bonding portion 5.

[0049] In FIG. 9 (upper figure), the uppermost protective film 4 to be removed is indicated by dot-shaped hatching. Also, for simplicity, in the cross-section of the second metal plate 3B shown in FIG. 9 (upper and lower figures), the illustration of the protective film 4 formed on the exposed surface other than the second groove portion 31B is omitted.

[0050] According to this embodiment, when the heat pipe body 10 is composed of the metal plate 3 on which the protective film 4 is formed, the bonding portion 5 can be formed by a metal bonding layer 52 or direct bonding instead of the resin bonding layer 51. Therefore, it is possible to miniaturize while ensuring the corrosion resistance of the heat pipe body 10, and it is possible to realize the self-excited vibration heat pipe 1 that achieves both good heat transport performance and improved manufacturability.

[0051] (Test Example 1) Next, a self-excited vibrating heat pipe 1 for testing, having the configuration of Embodiment 2 described above, was fabricated and its performance was evaluated. As shown in Figure 10, the self-excited vibrating heat pipe 1 for testing consists of two metal plates 3 of the same size, one of which is a first metal plate 3A that serves as a cover plate, and the other is a second metal plate 3B that serves as a flow path plate. On the side of the second metal plate 3B that forms the abutment portion 30, a groove portion 31 that serves as a working fluid flow path 2 is provided in a predetermined range, and the heat pipe body 10 is formed by laminating it with the first metal plate 3A.

[0052] As shown in Figure 11, first, two aluminum metal plates 3, which will serve as the cover plate or flow channel plate, were prepared, and a groove 31 was formed in the second metal plate 3B, which will serve as the flow channel plate, by cutting (step S1). The sizes of the two metal plates 3 and the area in which the groove 31 was formed on the second metal plate 3B were as follows: Metal plate 3 (length 200 mm x width 48 mm x thickness 2 mm) Groove 31 (length 194 mm x width 38.75 mm)

[0053] Next, the first metal plate 3A and the second metal plate 3B were each subjected to surface treatment to form a protective coating 4 covering the surface that would become the abutting portion 30 (step S2). The surface treatment was performed by anodizing, which is an electrolytic treatment using the metal plate 3 as the anode, and an anodized coating made of aluminum oxide was formed as the protective coating 4. Furthermore, after pre-treatment with superheated steam was performed on the abutting surfaces of the first metal plate 3A and the second metal plate 3B on which the protective coating 4 was formed (step S3), a bonding material containing epoxy resin was applied (step S4).

[0054] As the bonding material, a high-Tg epoxy resin prepared as follows was used as the curable resin composition (Example 1). Specifically, 100 parts by mass of a mixture of bisphenol A type epoxy resin (jER828; manufactured by Mitsubishi Chemical Corporation, trade name) and trifunctional epoxy resin (jER630; manufactured by Mitsubishi Chemical Corporation, trade name) in a mass ratio of 8:2 was mixed, to which 8 parts by mass of dicyandiamide (DICY7; manufactured by Mitsubishi Chemical Corporation, trade name) was added as a curing agent, and 0.1 parts by mass of imidazole manufactured by Shikoku Chemicals, Inc. as a catalyst were weighed and added, and the mixture was stirred at room temperature to obtain a high-Tg epoxy resin.

[0055] Furthermore, water, which will serve as the working fluid, was injected into the working fluid channel 2 using a hypodermic needle so that the filling rate of the working fluid channel 2 was 20% by volume (step S5). Then, with the first metal plate 3A and the second metal plate 3B in abutted position, the bonding material was heated and cured (step S6). In this way, a joint 5 made of a resin bonding layer 51 was provided at the abutment portion 30, the first metal plate 3A and the second metal plate 3B were joined via the joint 5, and a heat pipe body 10 with the working fluid channel 2 sealed was manufactured and its performance was evaluated (step S7).

[0056] In this instance, as shown in Table 1, in addition to Example 1, which used a bonding material of 100% by mass of high-Tg epoxy resin, heat pipe bodies 10 were also fabricated in the same manner using a bonding material containing polyethersulfone (PES), an amorphous thermoplastic resin composition, in an amount ranging from 10% by mass to 60% by mass (Examples 2-5). As the PES used, Sumika Excel PES5003PS (manufactured by Sumitomo Chemical Co., Ltd., trade name) was used.

[0057] Furthermore, a heat pipe body 10 was prepared in the same manner using a material in which the amorphous thermoplastic resin composition was replaced with polyphenylene oxide (PPO) instead of PES, and the blending ratio of high-Tg epoxy resin to PPO was set to 80:20 (mass ratio) (Example 6). SA90-100 (product name, manufactured by SHPP Japan LLC) was used as the PPO. The results of the evaluation of adhesive strength, heat resistance, thermal resistance, and corrosion resistance for the heat pipe bodies 10 of Examples 1 to 6 are shown in Table 1.

[0058] As schematically shown in Figure 12, the thermal resistance was calculated using the following formula based on Fourier's law, by measuring the temperature difference (T1-T2) and heat flow rate (Q) of the heating section H and heat dissipation section C located at both ends in the flow direction. Formula: Thermal resistance = (T1-T2) / Q The adhesive strength was the load per unit area at which the joint 5 broke when a load was applied to the heat pipe body 10, and the heat resistance (leak temperature) was the temperature at which leakage of the working fluid occurred when the heat pipe body 10 was placed in a constant temperature bath and its temperature was raised. Corrosion resistance was determined from the observation results of the protective coating 4 in the groove 31 which becomes the working fluid flow path 2, with good coating being judged as acceptable and insufficient as unacceptable.

[0059] Furthermore, similar to Example 3, a heat pipe body 10 was fabricated in the same manner, with a mixing ratio of high-Tg epoxy resin to PES set to 80:20 (mass ratio), and the filling rate of the working fluid varied in the range of 10 to 80 volume percent (Examples 7 to 10).

[0060] Furthermore, in a case where the protective coating 4 formed on the metal plate 3 was replaced with a boehmite coating instead of an anodized coating, a heat pipe body 10 was manufactured in the same manner using a bonding material with the same composition ratio as in Example 3 (Example 11). The boehmite treatment was carried out by treating with an oxidizing agent in high-temperature saturated steam to produce a protective coating 4 made of monohydrated aluminum oxide.

[0061] Next, the curable resin composition used as the bonding material was changed to a low-Tg epoxy resin prepared as follows, and the heat pipe body 10 was manufactured in the same manner (Examples 12-14). Specifically, 100 parts by mass of bisphenol A type epoxy resin (jER828; manufactured by Mitsubishi Chemical Corporation, trade name) was mixed with 8 parts by mass of dicyandiamide (DICY7; manufactured by Mitsubishi Chemical Corporation, trade name) as a curing agent and 0.1 parts by mass of imidazole manufactured by Shikoku Chemicals, Inc. as a catalyst, and the mixture was stirred at room temperature to obtain a low-Tg epoxy resin.

[0062] At this time, as shown in Table 1, in addition to using a bonding material with 100% by mass of low-Tg epoxy resin (Example 12), a heat pipe body 10 was manufactured in the same manner using a bonding material to which PES was added in a blending ratio of 20% by mass and 40% by mass (Examples 13-14).

[0063] The adhesive strength, heat resistance, thermal resistance, and corrosion resistance of the heat pipe bodies 10 of Examples 7 to 14 were evaluated in the same manner, and the results are shown in Table 1.

[0064]

[0065] As shown in Table 1, in Examples 1 to 11, which used bonding materials containing a high-epoxy resin, a curable resin composition, an adhesive strength of 30 MPa or higher was obtained in all cases. Furthermore, in Examples 2 to 5, in which PES was blended with the high-epoxy resin, the adhesive strength was higher than in Example 1, which did not contain PES, with the highest strength observed in Example 3, where the blending ratio was 20% by mass. In Example 6, where PPO was used instead of PES, a similar adhesive strength was obtained, confirming that blending an amorphous thermoplastic resin composition with a curable resin composition improves adhesive strength.

[0066] The heat resistance (leak temperature) of all of these Examples 1 to 11 exceeded 125°C, and the thermal resistance was also low, corresponding to the filling density of the working fluid. The leak temperature indicates that the effective glass transition temperature (Tg) of the bonding material is 125°C or higher. Furthermore, corrosion resistance is ensured by the formation of a protective coating 4 made of an anodized film. In this way, a high-performance self-oscillating heat pipe 1 can be obtained with good manufacturability.

[0067] In Examples 7 to 10, where the working fluid filling rate was 10% to 80% by volume, the thermal resistance was in the range of 0.03 K / W to 1.9 K / W, and the thermal resistance was lower at filling rates of 50% by volume or less. Similar results were obtained in Example 11, which had the same configuration as Example 7 but used a boehmite-treated protective coating 4. It has also been found that, for example, when the working fluid is water, the thermal resistance is equivalent to or lower than that at filling rates of 10% by volume or less (e.g., 5% by volume).

[0068] In Example 12, where the curable resin composition of Example 1 was replaced with a low-Tg epoxy resin, good results were obtained, with an adhesive strength of 28 MPa and heat resistance (leak temperature) of 100°C. Furthermore, in Examples 13-14, where PES was incorporated into the bonding material, the adhesive strength and heat resistance were improved.

[0069] (Test Example 2) Next, as shown in Table 2, heat pipe bodies 10 were manufactured and evaluated in the same manner for examples in which the joining method or joining material was changed (Examples 15 to 17). In Example 15, the joining portion 5 of the metal plate 3 was replaced with a metal joining layer 52 made by ultrasonic soldering, instead of the resin joining layer 51 used in Test Example 1. Otherwise, the heat pipe body 10 was obtained in the same manner as in Example 1.

[0070] Furthermore, similar to Examples 2 to 5 in Test Example 1 above, a bonding material containing high-Tg epoxy resin and PES was used, and the heat pipe body 10 was obtained in the same manner except that the mixing ratio was changed to 95:5 (mass ratio) or 33:67 (mass ratio) (Examples 16 to 17).

[0071] The adhesive strength, heat resistance, thermal resistance, and corrosion resistance of the heat pipe bodies 10 of these Examples 15 to 17 were evaluated in the same manner, and the results are shown in Table 2.

[0072] For comparison, a heat pipe body 10 was manufactured in the same manner as in Example 15, except that the method of joining the metal plates 3 on which the protective coating 4 was formed was changed to brazing (Comparative Example 1). Furthermore, a heat pipe body 10 was manufactured in the same manner in which the anodizing treatment for forming the protective coating 4 was omitted and joining was performed by brazing (Comparative Example 2).

[0073] Furthermore, in a conventional configuration in which a multi-hole tube is formed through a metal block without using a laminate of metal plates 3, the heat pipe body 10 was manufactured by anodizing and then closing the opening of the flow path (Comparative Example 3). The opening was closed by using epoxy resin adhesive to join the metal members that would become the closed ends, thereby sealing the internal flow path.

[0074] The adhesive strength, heat resistance, thermal resistance, and corrosion resistance of the heat pipe bodies 10 of these comparative examples 1 to 3 were evaluated in the same manner, and the results are shown in Table 2.

[0075] As shown in Table 2, in Example 15, where the joint 5 was a metal joint layer 52 formed by ultrasonic soldering, good results were obtained in terms of adhesive strength, heat resistance, thermal resistance, and corrosion resistance. On the other hand, in Comparative Example 1, which used brazing, although the adhesive strength improved, the heat resistance was insufficient and the corrosion resistance decreased. In Comparative Example 2, where brazing was performed without surface treatment, although the heat resistance and thermal resistance improved, it was not possible to use an aqueous working fluid, resulting in decreased corrosion resistance. In Comparative Example 3, which has a conventional configuration, surface treatment inside the flow path is difficult, resulting in decreased corrosion resistance. Alternatively, surface treatment is time-consuming, reducing manufacturability.

[0076] Furthermore, in Examples 16-17, where the resin bonding layer 51 was used and the PES blending ratio was lower or higher than that of Examples 2-14, an effect of increasing adhesive strength was also observed. Thus, when using the resin bonding layer 51, it is possible to achieve the desired adhesive strength by appropriately combining the curable resin composition and the amorphous thermoplastic resin composition and adjusting the blending ratio.

[0077]

[0078] (Embodiment 4) Embodiment 4 relating to a self-excited vibrating heat pipe will be described with reference to Figures 13 to 14. In the above embodiment, the working fluid passage 2 of the heat pipe body 10 has a rectangular cross-sectional shape, and the groove portion 31 constituting the passage wall 21 has a square concave groove shape. In this embodiment, however, the shape of the working fluid passage 2 and the groove portion 31 are changed. The basic configuration of the self-excited vibrating heat pipe 1 is the same as that of Embodiment 1 above, and the differences will be described below.

[0079] As shown in Figure 13, the heat pipe body 10 is constructed by laminating a first metal plate 3A and a second metal plate 3B, each having a first groove 31A and a second groove 31B, respectively. The working fluid passage 2 has a circular cross-sectional shape, and the first groove 31A and the second groove 31B are configured as semi-circular concave grooves corresponding to half of the passage wall 21. In this case as well, the symmetrical structure in the lamination direction provides a stress-relieving effect, and since there are no corners on the passage wall 21 of the working fluid passage 2, it becomes easier to uniformly form the protective coating 4.

[0080] Alternatively, as shown in Figure 14, the working fluid passage 2 of the heat pipe body 10 can have a square cross-sectional shape, with the two diagonally opposite vertices aligned in the Y or Z direction. The working fluid passage 2 is not limited to a square cross-section; it may also have a rhombus cross-sectional shape. The first groove 31A and the second groove 31B are configured as V-shaped recessed grooves corresponding to half of the passage wall 21. In this case as well, the symmetrical structure in the stacking direction provides a stress-relieving effect. Furthermore, since the corners of the passage wall 21 are located at the bottom of the V-shaped first groove 31A and the second groove 31B, treatment solutions such as surface treatments can easily flow through the corners, enabling the formation of a uniform coating.

[0081] Thus, the cross-sectional shape of the working fluid channel 2 and the shape of the grooves 31 that constitute the channel wall 21 are arbitrary and can be changed as appropriate depending on the ease of forming and processing the channel wall 21. With such a configuration, it is possible to miniaturize the heat pipe body 10 while ensuring corrosion resistance, and a self-excited vibrating heat pipe 1 that achieves both good heat transport performance and improved manufacturability can be realized.

[0082] (Embodiment 5) Embodiment 5 relating to a self-excited vibrating heat pipe will be described with reference to Figures 15 to 16. In the above embodiment, the heat pipe body 10 was a two-layer laminated structure, but in this embodiment, it is a three-layer laminated structure and has multiple pairs of adjacent metal plates 3. The basic configuration of the self-excited vibrating heat pipe 1 is the same as in Embodiment 2 above, and the differences will be described below.

[0083] As shown in Figure 15, the heat pipe body 10 has a third metal plate 3C between the first metal plate 3A and the second metal plate 3B. The third metal plate 3C and the first metal plate 3A or the second metal plate 3B each constitute two adjacent metal plates 3 separated by different abutment portions 30. Of these metal plates 3, the second metal plate 3B and the third metal plate 3C have groove portions 31 formed at the same locations, which serve as working fluid passages 2. That is, the grooves that become the straight portions 22 of the working fluid passages 2 extend in the X direction, and the folded portions 23 are arranged side by side in the Z direction. Furthermore, the groove portions 31 of the second metal plate 3B and the groove portions 31 of the third metal plate 3C are connected at both ends by communication holes 24 that penetrate the third metal plate 3C.

[0084] As shown in Figure 16 (upper and lower figures), adjacent second metal plate 3B and third metal plate 3C are provided with grooves 31 that form meandering flow channels of the same shape. The third metal plate 3C, which separates the two grooves 31, has a communication hole 24 that penetrates the bottom of the groove 31 at a position that will be the end of the meandering flow channel, and communicates with the end of the groove 31 of the second metal plate 3B, which is located opposite in the Y direction. At the other end of the meandering flow channel (not shown), the grooves 31 are also connected to each other via the communication hole 24. As a result, the working fluid flow channel 2 is a continuous two-layer meandering flow channel.

[0085] In this way, the heat pipe body 10 is constructed by stacking multiple metal plates 3 that serve as flow path plates, with a first metal plate 3A that serves as a cover plate stacked on top, thereby increasing the flow path length according to the number of stacks. At this time, the groove portion 31 of the second metal plate 3B, which is the bottom layer, is closed when a third metal plate 3C is stacked on top, and the groove portion 31 of the third metal plate 3C is closed by the first metal plate 3A that serves as a cover plate.

[0086] According to this embodiment, the heat pipe body 10 is constructed of a laminated structure with three or more layers. For example, even when installation space is limited, the flow path length of the working fluid flow path 2 can be secured by adjusting the outer shape and number of layers of the heat pipe body 10. Furthermore, by configuring the flow path three-dimensionally, the direction of heat transport can be controlled and the number of flow paths can be increased, which is expected to improve performance. Therefore, it becomes possible to miniaturize the heat pipe body 10 while ensuring corrosion resistance, and a self-excited vibrating heat pipe 1 that achieves both good heat transport performance and improved manufacturability can be realized.

[0087] (Embodiment 6) Embodiment 6 relating to a self-excited vibrating heat pipe will be described with reference to Figures 17 to 19. In the above embodiment, a heating section H and a heat dissipation section C were arranged at both ends of the heat pipe body 10 in the flow direction. In this embodiment, the arrangement of the heating section H or the heat dissipation section C is changed, and the shape of the working fluid flow path 2 is changed accordingly. The basic configuration of the self-excited vibrating heat pipe 1 is the same as that of Embodiment 1 above, and the differences will be described below.

[0088] As shown in Figure 17 (left), the self-excited vibrating heat pipe 1 may be configured such that a heating section H is positioned in the X direction, corresponding to the middle section of the heat pipe body 10, and heat dissipation sections C are positioned on both sides of the heating section H. In this case, as shown in Figure 17 (right), in addition to the folded sections 23 at both ends in the X direction, a folded section 231 is also provided in the middle section. That is, the working fluid flow path 2 has multiple straight sections 22 arranged in the Z direction, corresponding to each of the two heating sections H, and is connected to the folded sections 23 at the ends in the X direction and the folded sections 231 in the middle section.

[0089] In this configuration, the intermediate folded portion 231 is not provided at both ends in the Z direction, and the straight portion 22 extending to both ends in the X direction forms a continuous working fluid flow path 2. As a result, the working fluid flow path 2 becomes a meandering flow path in which the fluid flows back and forth between the heating portion H and the heat dissipation portion C on one side of the two heating portions H, and then flows back and forth similarly on the other side.

[0090] Thus, the arrangement of the heating section H and the heat dissipation section C can be arbitrarily changed, and by changing the flow path configuration of the working fluid flow path 2 accordingly, the same effects as in the embodiment 1 can be obtained.

[0091] Figure 18 shows a modified example of this embodiment. As shown in Figure 18 (left), a heating section H is arranged in the central part of the heat pipe body 10, and a heat dissipation section C is arranged to surround the heating section H. In this case, as shown in Figure 18 (right), a plurality of straight sections 22 can be arranged radially, and arc-shaped folded sections 232 and 233 can be provided to connect the straight sections 22. That is, the working fluid flow path 2 is configured as a meandering flow path in which the fluid folds back towards the inner circumference at the folded section 232 on the outer circumference corresponding to the heat dissipation section C, and then folds back towards the outer circumference at the folded section 233 on the inner circumference corresponding to the heating section H.

[0092] Furthermore, in the modified form shown in Figure 19, the shape of the heat pipe body 10 is modified to bend in an arc shape. In this case, a heating section H and a heat dissipation section C are arranged at both ends in the direction in which the arc extends, and a plurality of arc-shaped straight sections 22 and folded sections 23 are arranged to reciprocate between them. The same effects as in the first embodiment can be obtained with these modified forms as well.

[0093] (Embodiment 7) Embodiment 7 relating to a self-excited vibrating heat pipe will be described with reference to Figures 20 to 21. In this embodiment, as shown in Embodiment 6 above, the heating section H is located in the center of the heat pipe body 10 (see Figure 15), and the metal plate 3 that serves as the flow path plate has a laminated structure. In this case, the configuration shown in Embodiment 5 above (see Figure 15) can be adopted. The differences will be described below.

[0094] In Figure 20, the self-excited vibrating heat pipe 1 is constructed as a three-layer laminate formed by stacking a first metal plate 3A which serves as a cover plate and two metal plates 3 which serve as flow path plates. The second metal plate 3B and the third metal plate 3C, which serve as flow path plates, have grooves 31 of the same shape that serve as working fluid flow paths 2, and are stacked so that the flow directions are perpendicular to each other. Specifically, the grooves 31 of the third metal plate 3C have multiple straight sections 22 extending in the X direction, while the grooves 31 of the second metal plate 3B have multiple straight sections 22 extending in the Z direction and are connected by folded sections 23 aligned in the X direction.

[0095] Furthermore, both ends of the groove 31 of the third metal plate 3C are positioned diagonally opposite each other on the rectangular metal plate 3, and both ends of the groove 31 of the second metal plate 3B are positioned at equivalent locations in the Y direction. Communication holes 24 corresponding to the positions of both ends of the groove 31 are formed through the third metal plate 3C and are connected to both ends of the groove 31 of the second metal plate 3B.

[0096] By configuring the flow path in this way, the direction of the working fluid flow, i.e., the direction of heat transport, is 90 degrees different between the second metal plate 3B and the third metal plate 3C. This allows grooves 31, which serve as flow paths, to be formed across the entire surface of the multiple metal plates 3 that serve as flow path plates. By stacking them with their orientations changed, the flow paths can be efficiently utilized to spread heat in the in-plane direction (X direction and Z direction) of each metal plate 3.

[0097] As shown in the modified example in Figure 21, the heat pipe body 10, which has a laminated structure, can also be configured with a number of heat dissipation fins F arranged on its outer surface. Furthermore, a flow path that serves as the working fluid flow path 2 can be formed inside the fins F. The fins F, which form the heat dissipation section C, and the heating section H are located on opposite sides of the heat pipe body 10 in the Y direction, and the configuration allows for heat transfer from one side to the other in the Y direction.

[0098] In this case, a working fluid channel 2 is provided inside the heat pipe body 10, formed by grooves 31 in multiple metal plates 3, and is connected to a channel formed inside the fin F. The grooves 31 in the multiple metal plates 3 allow the working fluid to flow in a folded manner from the central part where the heating section H is provided outwards, for example, and are connected by communication holes 24. Furthermore, they are connected to the folded channel F1 formed in the fin F, forming a continuous working fluid channel 2. The ends of the folded channel F1 and the grooves 31 can be connected, for example, by through holes that serve as communication holes 25. This increases the length of the working fluid channel 2, enabling efficient heat transport by utilizing the inside of the heat pipe body 10 and the fin.

[0099] Thus, this configuration also makes it possible to miniaturize the heat pipe body 10 while ensuring its corrosion resistance. Furthermore, it is possible to realize a self-excited vibrating heat pipe 1 that achieves both good heat transport performance and improved manufacturability.

[0100] This disclosure is described in accordance with embodiments, but it is understood that this disclosure is not limited to such embodiments or structures. This disclosure also includes various modifications and variations within the scope of equivalents. In addition, various combinations and forms, as well as other combinations and forms that include only one, more, or fewer of those elements, fall within the scope and idea of ​​this disclosure.

[0101] This disclosure is not limited to the uses shown in the embodiments described above, and can be applied to various embodiments in uses that do not depart from its essence. Furthermore, the configurations shown in the embodiments described above can be combined. Examples of the embodiments of this disclosure are shown below. [Item 1] A self-excited vibrating heat pipe (1) comprising: a metal heat pipe body (10) with a working fluid passage (2) inside which a working fluid is sealed; a heating section (H) for supplying heat from outside the heat pipe body to the working fluid; and a heat dissipation section (C) for releasing heat from the working fluid to the outside, wherein the working fluid transports heat by moving between the heating section and the heat dissipation section in the working fluid passage; the heat pipe body is made of a laminate including a plurality of metal plates (3), and the abutting section (30) of two adjacent metal plates in the lamination direction (Y) has grooves (31) that constitute the working fluid passage, and a joint (5) that seals the working fluid passage; and the metal plates have a protective coating (4) that covers at least the surface that becomes the passage wall (21) of the working fluid passage. [Clause 2] The self-excited vibrating heat pipe according to Claim 1, wherein at least one of the two adjacent metal plates is provided with the groove, and the groove has a meandering flow path shape that folds back and forth between the heating portion and the heat dissipation portion. [Clause 3] The self-excited vibrating heat pipe according to Claim 1, wherein the joint comprises a resin bonding layer (51) interposed between the two adjacent metal plates, and the resin bonding layer is made of a bonding material containing a curable resin composition. [Clause 4] The self-excited vibrating heat pipe according to Claim 3, wherein the bonding material comprises the curable resin composition and an amorphous thermoplastic resin. [Clause 5] The self-excited vibrating heat pipe according to Claim 4, wherein the bonding material has a mixing ratio of the curable resin composition and the amorphous thermoplastic resin of 97:3 to 30:70 by mass. [Clause 6] The self-excited vibrating heat pipe according to Claim 4 or Claim 5, wherein the curable resin composition comprises an epoxy resin, and the amorphous thermoplastic resin comprises a polyethersulfone or a polyphenylene oxide. [Item 7] The bonding material is a self-excited vibrating heat pipe according to any one of items 3 to 6, wherein the glass transition temperature is 100°C or higher.[Clause 8] The self-excited vibrating heat pipe according to Clause 1, wherein at the joint, two adjacent metal plates are joined via a metal bonding layer (52) or directly. [Clause 9] The self-excited vibrating heat pipe according to any one of Clauses 1 to 8, wherein the metal plates are made of aluminum or an aluminum alloy, and the protective coating is an anodized film or a boehmite film. [Clause 10] The self-excited vibrating heat pipe according to any one of Clauses 1 to 9, wherein the filling rate of the working fluid in the working fluid passage is 80 volume percent or less. [Clause 11] The self-excited vibrating heat pipe according to any one of Clauses 1 to 10, wherein the grooves are provided on both of the two adjacent metal plates, and the two grooves provided on the two metal plates are arranged opposite each other with the abutting portion facing the opening side. [Item 12] The self-excited vibrating heat pipe according to any one of items 1 to 10, wherein the grooves are provided on both of the two adjacent metal plates, and the two grooves provided on the two metal plates are arranged to correspond to different abutting portions, and are in communication with each other through a communication hole (24) provided in the metal plate separating the two grooves.

Claims

1. A self-excited vibrating heat pipe (1) comprising: a metal heat pipe body (10) with a working fluid passage (2) inside which a working fluid is sealed; a heating section (H) for supplying heat from outside the heat pipe body to the working fluid; and a heat dissipation section (C) for releasing heat from the working fluid to the outside; wherein the working fluid transports heat by moving between the heating section and the heat dissipation section in the working fluid passage; the heat pipe body is made of a laminate including a plurality of metal plates (3), and the abutting section (30) of two adjacent metal plates in the lamination direction (Y) has grooves (31) that constitute the working fluid passage, and a joint (5) that seals the working fluid passage; and the metal plates have a protective coating (4) that covers at least the surface that becomes the passage wall (21) of the working fluid passage.

2. The self-excited vibrating heat pipe according to claim 1, wherein at least one of the two adjacent metal plates is provided with the groove, and the groove has a meandering flow path shape that folds back and forth between the heating portion and the heat dissipation portion.

3. The self-excited vibrating heat pipe according to claim 1, wherein the joint portion comprises a resin bonding layer (51) interposed between two adjacent metal plates, and the resin bonding layer is made of a bonding material containing a curable resin composition.

4. The self-excited vibrating heat pipe according to claim 3, wherein the bonding material comprises the curable resin composition and an amorphous thermoplastic resin.

5. The self-excited vibrating heat pipe according to claim 4, wherein the blending ratio of the curable resin composition to the amorphous thermoplastic resin in the bonding material is 97:3 to 30:70 by mass ratio.

6. The self-excited vibrating heat pipe according to claim 4, wherein the curable resin composition comprises an epoxy resin, and the amorphous thermoplastic resin comprises a polyethersulfone or a polyphenylene oxide.

7. The self-excited vibrating heat pipe according to claim 3, wherein the bonding material has a glass transition temperature of 100°C or higher.

8. The self-excited vibrating heat pipe according to claim 1, wherein at the joint, two adjacent metal plates are joined via a metal bonding layer (52) or directly.

9. The self-excited vibrating heat pipe according to any one of claims 1 to 8, wherein the metal plate is made of aluminum or an aluminum alloy, and the protective coating is an anodized film or a boehmite film.

10. The self-excited vibrating heat pipe according to any one of claims 1 to 8, wherein the filling rate of the working fluid in the working fluid passage is 80 volume percent or less.

11. The self-excited vibrating heat pipe according to any one of claims 1 to 8, wherein the grooves are provided on both of the two adjacent metal plates, and the two grooves provided on the two metal plates are arranged facing each other with the abutting portion facing outwards.

12. The self-excited vibrating heat pipe according to any one of claims 1 to 8, wherein the grooves are provided on both of the two adjacent metal plates, and the two grooves provided on the two metal plates are arranged to correspond to different abutting portions, and are in communication with each other through a communication hole (24) provided in the metal plate separating the two grooves.

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