Patent ID: 12253314

DETAILED DESCRIPTION OF THE INVENTION

The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.

FIG.3Ais a schematic diagram of the appearance of the heat pipe of an embodiment of the invention, andFIG.3Bis a schematic sectional diagram of the heat pipe taken along the line A-A inFIG.3A. As shown inFIGS.3A and3B, in this embodiment, the heat pipe H5includes a pipe1eand at least a wick structure2e. A single wick structure2eis illustrated as an example herein. The pipe1ehas a hollow chamber10e, and the wick structure2eis disposed in the hollow chamber10eand extended along the axial direction D1of the pipe1e. The pipe1eis a flat and cylindrical thin-type hollow tube. The pipe1ecan be made by, for example, copper, silver, aluminum, their alloy or other metal materials with well heat transfer property. In the practical application, in addition to the wick structure2e, a working fluid (not shown) is also disposed in the pipe1eand can be any fluid helping the evaporation and heat dissipation, such as inorganic compounds, alcohols, ketones, liquid metal, refrigerant, organic compounds or their any mixture. Moreover, the pipe1eis not limited here in shape or dimensions, which can be a cylindrical tube or rectangular tube and can be determined according to the surrounding environment, space, heat transfer requirement or temperature.

As shown inFIGS.3A and3B, the wick structure2eof this embodiment is formed outside the pipe1e. In detail, the wick structure2eis formed outside the pipe1efirst, and can be formed by the high sintering and/or injection molding, but this invention is not limited thereto. Besides, before the wick structure2eis disposed to the pipe1e, the porosity and permeability thereof are properly controlled by the forming method so as to enhance the capillarity of the wick structure, and therefore the amount of the working fluid flowing back to the evaporator can be increased and the maximum heat transfer amount (Qmax) of the heat pipe can be effectively increased.

The conventional wick core structure of the heat pipe is made by disposing a core rod in the metal pipe to fix the metal powder and also formed by the high sintering, but the core rod has a high cost and may be damaged during the process of the sintering or removing the core rod, and even the wick structure may be also damaged, so that the performance of the heat pipe is reduced. However, the wick structure2eof this embodiment is formed on the outside firstly, and the form of the wick structure can be designed according to the performance requirement and won't be limited by the core rod required for the conventional process. Besides, favorably, the quality of the wick structure2ecan be examined outside the pipe1efirstly to eliminate the defective products in advance so as to enhance the yield of the heat pipe H5.

As shown inFIGS.3A and3B, in this embodiment, the section P5of the wick structure2ealong the axial direction D1of the pipe1ehas a discontinuous edge and is not a uniform section between the two ends E1, E2of the pipe1e. In other words, the section P5can be divided into the sections P51, P52, P53from one end E1of the pipe1eto the other end E2, and the section P52is located between the sections P51and P53. Besides, the section P52has a greater area than the sections P51and P53. In other words, the middle region of the heat pipe H5can be used as the evaporator of the heat pipe, and in practice, this middle region can be attached to the heat source so as to achieve a better heat-dissipation effect.

In addition to the above-mentioned structure, the discontinuous edge of the section of the wick structure along the axial direction also can be applied to the cases ofFIGS.3C and3D, which are schematic sectional diagrams taken along the line A-A of the heat pipe ofFIG.3Aaccording to different embodiments of the invention. The appearance inFIG.3Awith the line A-A is just for showing the position of the sections inFIGS.3C and3D, andFIGS.3C and3Dactually show the heat pipe structures of different embodiments. As shown inFIGS.3A,3C,3D, particularly, the structures of the heat pipes H6, H7are substantially the same as the heat pipe H5of the above embodiment, wherein each of the sections P6, P7of the wick structures2f,2gof the heat pipes H6, H7along the axial direction D1of the pipes1f,1gis not a uniform section between the two ends of each of the pipes1f,1g, and besides, the sections of the wick structures2f,2galong the axial direction of the pipes both have a discontinuous edge. However, the section P6of the heat pipe H6has a less area at the middle region between the two ends E1, E2of the pipe1fbut has a greater area at the ends E1, E2; and the section P7of the heat pipe H7has a greater area at the end E1of the pipe1gbut has a less area at the end E2. In practice, the region of the section with a greater area can be attached to the heat source so as to achieve a better heat-dissipation effect.

The form of the edge of the section of the wick structure of the above-mentioned heat pipes H5, H6, H7is not meant to be construed in a limiting sense.FIG.4Ais a schematic diagram of the appearance of the heat pipe of another embodiment of the invention, andFIGS.4B,4C,4Dare schematic sectional diagrams of the heat pipe inFIG.4Ataken along the line B-B according to different embodiments. As shown inFIGS.4A to4D, in the heat pipes H8, H9, H10, the sections of the wick structures2h,2i,2jalong the axial directions of the pipes1h,1i,1jall have a continuous edge. In other words, the edge of each of the sections of the wick structures2h,2i,2jhas a smooth form without the sectional difference. In comparison with the above embodiments, since the heat pipes H8, H9, H10of this embodiment have the continuous edges, the less flow resistance can be generated and the maximum thermal design power of the heat pipes H8, H9, H10can be thus enhanced.

Besides, the thickness variation along the axial direction of the heat pipes H8, H9, H10is shown asFIG.4E, which is a schematic sectional diagram of the heat pipe inFIG.4Ataken along the line B′-B′. The wick structures2h,2i,2jof the heat pipes H8, H9, H10have the thickness variation along the axial direction, but this thickness variation is not meant to be construed in a limiting sense and can be adjusted according to the change of the heat source position.

In addition to the above embodiments, this invention further includes the wick structures of other types.FIG.5Ais a schematic diagram of the appearance of the heat pipe of another embodiment of the invention,FIGS.5B and5Dare schematic perspective sectional diagrams of the heat pipe inFIG.5Ataken along the line C-C according to different embodiments, andFIGS.5C and5Eare schematic sectional diagrams of the heat pipes ofFIGS.5B and5Drespectively. The appearance inFIG.5Awith the line C-C is just for showing the position of the sections inFIGS.5B and5D, andFIGS.5B and5Dactually show the heat pipe structures of different embodiments. Particularly, like the heat pipe H5of the above embodiment, each of the sections of the wick structures2k,2mof the heat pipes H11, H12along the axial direction D1of the pipes1k,1mis not a uniform section between the two ends of each of the pipes1k,1m. In detail, the wick structures2k,2mboth have a varied thickness in the view of the heat pipes H11, H12along the radial direction. The thicker region (such as the region R1) can be used to be attached to the portion of the heat source T having a higher temperature, and the thinner region (such as the region R2) can be used to be attached to the portion of the heat source T having a lower temperature. In other words, the wick structures2k,2mof the heat pipes H11, H12of this embodiment both have the thickness variation along the redial direction. However, the distribution and variation of the thickness of the wick structure is not meant to be construed in a limiting sense, and the wick structures2k,2mcan be adjusted according to the space and performance of the pipes1k,1mor the heat-dissipation requirement. The related application will be illustrated hereinafter.

In other embodiments, the embodiments of the heat pipes H8, H9, H10also can be combined with the embodiments of the heat pipes H11, H12. For example, the wick structure of the heat pipe can be adjusted in both of the axial and radial directions so as to meet the actual heat-dissipation requirement, but this invention is not limited thereto.

FIG.6Ais a schematic diagram of a part of the appearance of the heat pipe of an embodiment of the invention, andFIG.6Bis a schematic sectional diagram of the heat pipe inFIG.6Ataken along the line D-D. As shown inFIGS.6A and6B, in comparison with the above embodiments, the heat pipe H13includes a larger pipe1n. In other words, the pipe1nincludes a larger hollow chamber10n. The heat pipe H13includes a plurality of wick structures2ndisposed adjacent to each other in the pipe1n. Through the disposition of a plurality of wick structures2n, a flat heat pipe H13with a larger area can be formed. Besides, the wick structure2nof this embodiment further includes at least a support portion21n(herein for example, each of the wick structures2nincludes a support portion21n), and the support portion21nhas the same material as the wick structure2n. The support portion21npresses the inner wall of the pipe1nto act as a support structure so as to prevent the depression and deformation of the heat pipe H13.

In practice, the above different heat pipe structures can be combined together to enhance the applicability of the heat pipe. As shown inFIG.7where two heat pipes H11disposed side by side to form the heat pipe H14for the illustrative purpose, when the heat pipe H14is viewed in the radial direction, the wick structure2phas a varied thickness. The thicker region (such as the region R3) can act as the evaporator of the heat pipe H14and the thinner region (such as the region R4) can act as the condenser of the heat pipe H14. In detail, the region R3of the heat pipe H14can be disposed closer to the heat source T and the region R4can be disposed away from the heat source T. Since the thicker region of the wick structure2phas stronger capillarity, the working fluid will be provided with a better capability of flowing back and the thicker region can bear larger heat flux and temporary heat impact, and therefore the heat pipe H14can operate stably to avoid the idle heating condition. In practice, a thin metal plate M (such as a copper plate) can be disposed on the heat source T so as to evenly disperse the heat of the heat source T and make an evener heating surface.

Summarily, the wick structure of the heat pipe of this invention can be varied in form along the axial direction of the pipe so as to meet the structure requirement of the evaporator, heat insulator and condenser of the heat pipe and can be adjusted according to the space and performance of the pipe of the heat pipe or according to the actual heat-dissipation requirement.

The conventional wick core structure of the heat pipe is made by disposing a core rod in the metal pipe to fix the metal powder and also formed by the high sintering, but the core rod has a high cost and may be damaged during the process of the sintering or removing the core rod, and even the wick structure may be also damaged, so that the performance of the heat pipe is reduced. However, the wick structure of this embodiment is formed on the outside firstly, and the form of the wick structure can be designed according to the performance requirement and won't be limited by the core rod required for the conventional process. Besides, favorably, the quality of the wick structure can be examined outside the pipe firstly to eliminate the defective products in advance so as to enhance the yield of the heat pipe.

Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments, will be apparent to persons skilled in the art. It is, therefore, contemplated that the appended claims will cover all modifications that fall within the true scope of the invention.