US20140290914A1

US20140290914A1 - Heat pipe structure

Info

Publication number: US20140290914A1
Application number: US14/222,676
Authority: US
Inventors: Ing-Jer Chiou; Cheng-Yu Wang
Original assignee: Asustek Computer Inc
Current assignee: Asustek Computer Inc
Priority date: 2013-03-26
Filing date: 2014-03-23
Publication date: 2014-10-02
Also published as: TW201437591A

Abstract

A heat pipe structure includes a hollow tube body and a plurality of capillary structures. A first region and a second region are defined in the hollow tube body. The capillary structure is disposed on the first region. A diameter of the second region is larger than a diameter of the first region.

Description

RELATED APPLICATIONS

This application claims priority to Taiwan Application Serial Number 102110680, filed Mar. 26, 2013, the entirety of which is herein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention
This invention relates to a heat pipe structure.
2. Description of the Related Art
The body of the heat pipe is usually made of copper, and the working fluid of the heat pipe is usually water. When one end of the heat pipe is in a higher temperature and the other end of the heat pipe is in a lower temperature, the working fluid adsorbed by a capillary structure at higher temperature evaporates. The evaporated air is gathered in the pipe, and the fluid flows to the part of the heat pipe in lower temperature because of the pressure. When the gaseous fluid flows to the part in lower temperature, the gaseous fluid is condensed to the liquid fluid, and it is adsorbed by the capillary structure at the lower temperature part. Then, the liquid fluid flows back to the part with higher temperature from the part of the capillary structure with lower temperature by the capillarity. The working fluid is changed between the gaseous state and the liquid state circularly to conduct the heat, which is a principle of the heat transfer in the heat pipe.
However, the capillary structure of the heat pipe usually enclosed inside the heat pipe. The sectional shape of the heat pipe is rectangle or oval. Since the space for the air to flow in the body is narrow and resulting a large resistance of the air flow, the efficiency of the heat transfer is low. Furthermore, the outer surface of a conventional heat pipe contacts the casing of an electronic device, and the heat would conduct to the casing via the outer surface of the heat pipe, which resulting a high temperature of the easing of an electronic device.
Additionally, the space inside the body of the heat pipe that surrounded by the capillary structure is saved for the air to flow through, therefore, the strength of the body of the heat pipe is difficult to improve, and it easily deforms when an external force applied, in the production of heat pipes, the saved space for the air flow affects the yield of the heat pipe, and the yield of the heat pipe is difficult to control which is just about 60% at present. Moreover, the conventional heat pipe is no function in guiding the airflow when cooperating with a cooling fin and a fan.

BRIEF SUMMARY OF THE INVENTION

A heat pipe structure is provided.
The heat pipe structure includes a hollow tube body and a plurality of capillary structures. A first region and a second region are defined. The capillary structure is disposed on the inner wall of the first region. The diameter of the second region is larger than that of the first region.
The capillary structure is disposed in part of the inner wall of the hollow tube body, therefore the hollow tube body is not fulfilled by the capillary structure. To produce the heat pipe structure of the present disclosure, a mold applies to the heat pipe body via a pressure to form a second region and a first region. The inner wall of the second region of the hollow tube body disposes no capillary structure while the inner wall of the first region of the hollow tube body disposes with the capillary structure. Thus, the second region of the hollow tube body forms a channel for the air to flow through, and the efficiency of dissipating the heat is enhanced. Additionally; the first region of the body is disposed with the capillary structure, thus the strength of the heat pipe structure is improved, and the yield of the heat pipe structure is easy to be managed. When the heat pipe structure is pressed by the external force, it is not easily deformed and damaged.
When the casing of the electronic device contacts part of the heat pipe structure, the first region is not contact the casing of the electronic device, thus the heat would not accumulate on the casing of the electronic device, and the user feels more comfortable. Further, when the heat pipe structure is used cooperating with the fan, the second region of the heat pipe forms a channel to guide the airflow, which enhance heat dissipating efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a three dimensional schematic diagram showing a heat pipe structure in a first embodiment;

FIG. 2A is a sectional schematic diagram showing the heat pipe structure in FIG. 1 along the line segment 2-2;

FIG. 2B is a sectional schematic diagram showing the heat pipe structure in a second embodiment;

FIG. 3 is a schematic diagram showing that the heat pipe structure in FIG. 1 is used cooperating with the casing of the electronic device;

FIG. 4 is a schematic diagram showing the heat pipe structure in FIG. 2A in manufacturing;

FIG. 5 is a sectional schematic diagram showing the heat pipe structure in a third embodiment;

FIG. 6 is a sectional schematic diagram showing the heat pipe structure in FIG. 5 along the line segment 6-6;

FIG. 7 is a schematic diagram showing that the heat pipe structure in FIG. 5 is used with the casing of the electronic device, a heat sink, and a fan;

FIG. 8 is a side view showing the heat pipe structure, the heat source, and the casing of the electronic device viewed from the direction D2;

FIG. 9 is a sectional schematic diagram showing the heat pipe structure m a. fourth embodiment,

FIG. 10 is a sectional schematic diagram showing the heat pipe structure in a filth embodiment;

FIG. 11 is a sectional schematic diagram showing the heat pipe structure in a sixth embodiment;

FIG. 12 is a sectional schematic diagram showing the heat pipe structure in a seventh embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1 is a three dimensional diagram showing a heat pipe structure 100. FIG. 2A is a sectional schematic diagram showing the heat pipe structure in FIG. 1 along the line segment 2-2. Referring to FIG. 1 and FIG. 2A, the heat pipe structure 100 includes a hollow tube body 110 and a capillary structure 130. The heat pipe structure 100 accommodates a working fluid 120 therein. A first region 111 and a second region 113 are defined inside the hollow tube body 110. A capillary structure 130 is disposed on an inner wall of the first region 111. The inner wall is a surface of the hollow tube body 110 contacting the capillary structure 130. such as a first surface 117 and a second surface 119 of the first region 111. Furthermore, a diameter H of the part of the hollow tube body 110 on where the capillary structure 130 is not disposed (that is the hollow tube body 110 outside the second region 113) is larger than a diameter H′ of the other part of the hollow tube body 110 on where the capillary structure 130 is disposed (that is the hollow tube body 110 outside the first region 111). And the part of the hollow tube body 110 which is not attached with the capillary structure 130 is the second region 111, and the other part of the hollow tube body 110 which is attached with the capillary structure 130 is the first region.
In this embodiment, the capillary structure 130 contacts the first surface 117 and the second surface 119 of the hollow tube body 110. The capillary structure 130 may be one or a combination of metal sinters, micro grooves, fibers, mental nets, or any other heat conduction elements, which is not limited herein.
Furthermore, the second region 113 of the hollow tube body 110 is divided into two subspaces 114 and 116, the subspace 114 has a diameter H1, and the subspace 116 has a diameter H2. In this embodiment, the diameter H1 of the subspace 114 is same to the diameter H2 of the subspace 116. The diameter of the second region 113 (that is the diameter H1 and H2) is larger than a diameter H3 of the first region 111. The diameter of the capillary structure 130 is approximately same to the diameter 113 of the first region 111, and thus the diameter H1 and H2 of the subspaces 114 and 116 are all larger than the diameter of the capillary structure 130, respectively. The term “approximately” above means that it allows an error in manufacturing.
The working fluid 120 may be water, which is not limited herein. The liquid working fluid 120 (such as the liquid water) can be absorbed and transmitted by the capillary structure 130, and the gaseous working fluid 120 (such as the water vapor) can flow in the subspaces 114 and 116. Moreover, the accommodating space 112 in the hollow tube body 110 is vacuumized, and the pressure is less than 1 standard atmospheric pressure, and thus the boiling point of the working fluid 120 is reduced.
Since the capillary structure 130 is in the first region 111 and only disposed on the inner wall of the first region 111, the hollow tube body 110 is not fulfilled by the capillary structure 130. The second region of the hollow tube body 110 has enough space (such as the subspace 114 and 116) for the gaseous working fluid 120 to flow, and the efficiency of conducting heat is enhanced. Furthermore, the second region of the hollow tube body 110 is supported by the capillary structure 130, and thus the heat pipe structure 100 is not easily deformed and damaged when an external force applied.
FIG. 2B is a sectional schematic diagram showing the heat pipe structure 100′ in a second embodiment. The heat pipe structure 100′ includes the hollow tube body 110 and the capillary structure 130. The difference between this embodiment and the embodiment in FIG. 2A is that the capillary structure 130 contacts the first surface 117 of the first region 111 but not the second surface 119 of the first region 111. That is, the diameter of the capillary structure 130 is smaller than the diameter H3 of the first region 111.
FIG. 3 is a schematic, diagram showing that the heat pipe structure 100 is used inside the casing of the electronic device 216. A heat source 212 is disposed on a circuit board 214. The heat source 212 is an electronic component which generates heats while operation, such as a central processing, unit (CPU), a video chip, an audio chip, a network chip or a heat sink, which is not limited herein. The heat pipe structure 100 is disposed at the heat source 212 to transfer the heat produced by the heat source 212. When the casing of the electronic device 216 contacts part of the heat pipe structure 100, the first region of the hollow tube body 110 is not contact the casing of the electronic device 216 (that is a distance d1), and thus the casing of the electronic device 216 receives less heat from heat pipe, and the user feels more comfortable while operating.
FIG. 4 is a schematic diagram showing the heat pipe structure 100 in FIG. 2A in manufacturing. Referring to FIG. 2A and FIG. 4, the heat pipe structure 100 is not yet molded. The heat pipe structure 100′ includes the hollow tube body 110′ and the capillary structure 130′. In manufacturing the heat pipe structure 100, the part of the hollow tube body 110′ which is attached with the capillary structure 130′ is pressed by the molds 222 and 224 to form the first region, and the part of the hollow tube body 110′ which is not attached with the capillary structure 130′ forms the second region.
In this embodiment, the mold 222 includes two concaves. When the mold 222 presses the heat pipe structure 100′ along direction D1, the mold 222 can make the hollow tube body 110′ form the second region of the body 110 in FIG. 2A, the pressed central region of the hollow tube body 110′ forms the first region 111 of the hollow tube body 110 in FIG. 2A. Inside the first region 111 of the body 110 is disposed with the capillary structure 130, and thus the hollow tube body 110 would not be excessively squashed by the molds 222 and 224. Consequently, the yield of the heat pipe structure 100 is easy to be managed, the strength of the heat pipe structure 100 is enhanced, and the yield of the heat pipe structure 100 is increased to more than 80%.
FIG. 5 is a sectional schematic diagram showing the heat pipe structure 100 b in a third embodiment. FIG. 6 is a sectional schematic diagram showing the heat pipe structure in FIG. 5 along the line segment 6-6. Referring to FIG. 5 and FIG. 6, the heat pipe structure 100 b includes the hollow tube body 110 and the capillary structure 130. The difference between this embodiment and that in FIG. 1 and FIG. 2A is that: the capillary structure 130 not only contacts the first surface 117 and the second surface 119 of the hollow tube body 110 but also contacts the side 136 of the hollow tube body 110. In this embodiment, the diameter H4 of the second region 113 is larger than the diameter H5 of the first region 111.
FIG. 7 is a schematic diagram showing that the heat pipe structure 100 b in FIG. 5 is used with the casing of the electronic device 216, a heat sink 232, and a fan 234. FIG. 8 is a side view showing the heat pipe structure 100 b, the heat source 212, and the casing of the electronic device looked from the direction D2. Referring to FIG. 7 and FIG. 8, two ends of the heat pipe structure 100 b are disposed at the heat source 212 and the heat sink 232 respectively, and the casing of the electronic device 216 is covering the heat pipe structure 100 b and the fan 234. A distance d2 is formed between the first region of the hollow tube body 110 and the casing of the electronic device 216, where the first region of the hollow tube body 110 disposed with capillary structure 130 (as shown in FIG. 6), and compare to the first region, is the second region disposed with no capillary structure 130 (as shown in FIG. 6). When the fan 234 rotates, the second region of the hollow tube body 110 can be regarded as a baffle of the airflow W to make the airflow W flow along the heat pipe structure 100 b. Thus, the heat pipe structure 100 b guides the airflow W thus enhancing the heat dissipation efficiency for the heat source 212 and heat sink 231.
FIG. 9 is a sectional schematic diagram showing the heat pipe structure 100 c in a fourth embodiment. The heat pipe structure 100 c includes the hollow tube body 110 and the capillary structure 130. The difference between this embodiment and that in FIG. 2A the diameter H6 of the subspace 114 is larger than the diameter 117 of the first region 111, and the diameter H7 of the subspace 116 is approximately same to the diameter H7 of the first region 111. That is, the diameter H6 of the subspace 114 is larger than the diameter H7 of the subspace 116, and the first region 111 and the hollow tube body 110 outside the subspace 116 are at the same plane.
FIG. 10 is a sectional schematic diagram showing the heat pipe structure 100 d in a fifth embodiment. The heat pipe structure 100 d includes the hollow tube body 110 and the capillary structure 130. The difference between this embodiment and that in FIG. 2A are the diameter H8 of the subspace 114 is larger than the diameter 119 of the subspace 116, and the diameter H8 and H9 of the subspace 114 and 116 are all larger than the diameter H10 of the first region 111. In this embodiment, the diameter of the capillary structure 130 is approximately same to the diameter H10 of the first region 111.
The capillary structures 130 in the embodiments of FIG. 1 to FIG. 10 are single structures. Various of the capillary structures 130 are illustrated, hereinafter.
FIG. 11 is a sectional schematic diagram showing the heat pipe structure in a sixth embodiment. The heat pipe structure 100 e includes the hollow tube body 110 and the capillary structure 130. The difference between this embodiment and that in FIG. 2A is that the capillary structure 130 is divided into the first part 130 a and the second part 130 b. Where the first part 130 a of the capillary structure 130 contacts the first surface 117, and the second. part 130 b of the capillary structure 130 contacts the second surface 119. Furthermore, the first part 130 a is connected to the second part 130 b.
In this embodiment, the diameter H11 of the subspace 114 is larger than a sum diameter H13 (that is the diameter of the first region 111) of the first part 130 a and the second part 130 b. The diameter H12 of the subspace 116 is also larger than a sum diameter H3 of the first part 130 a and the second part 130 b of the capillary structure 130.
FIG. 12 is a sectional schematic diagram showing the heat pipe structure in a seventh embodiment. The heat pipe structure 100 f includes the hollow tube body 110 and the capillary structure 130. The difference between this embodiment and that in FIG. 11 are: the diameter H14 of the subspace 114 is larger than the diameter H15 of the subspace 116, and the diameter H15 of the subspace 116 is approximately same to the sum of diameter of the first part 130 a and diameter of the second part 130 b of the capillary structure 110 (that is the diameter of the first region 111).
The heat pipe structure in embodiments includes following advantages.
The capillary structure is disposed on part of the hollow tube body, and thus the hollow tube body is not fulfilled by the capillary structure. In manufacturing the heat pipe structure, the mold presses the part of the hollow tube body which is not attached with the capillary structure to make a second region. Thus, the second region of the hollow tube body has enough space for the air to flow, and the heat dissipation efficiency is enhanced. Furthermore, the first region of the hollow tube body is supported by the capillary structure, the yield of the heat pipe structure is easy to be managed, and the strength of the heat pipe structure is enhanced. When an external force is applied on the heat pipe structure, the heat pipe structure is not easily deformed and damaged.
When the casino of the electronic device contacts part of the heat pipe structure, the first region of the hollow tube body which is attached with the capillary structure is not contact the casing, of the electronic device, thus the heat would not accumulate on the casing of the electronic device, and it is more comfortable for the user while operating.
When the heat pipe structure is cooperated with the fan, the convex part of the hollow tube body on where the capillary structure 130 (that is the second part) is not disposed forms a channel to guide the airflow, and thus the efficiency of the heat pipe structure is increased.
Although the disclosure has been described in considerable detail with reference to certain preferred embodiments thereof, the disclosure is not for limiting the scope. Persons having ordinary skill in the art may make various modifications and changes without departing from the scope. Therefore, the scope of the appended claims should not he limited to the description of the preferred embodiments described above.

Claims

What is claimed is:

1. A heat pipe structure, comprising

a hollow tube body, defining a first region and a second region; and

a plurality of capillary structures disposed on the first region, wherein the diameter of the second region is larger than the diameter of the first region.

2. The heat pipe structure according to claim 1, wherein the first region includes a first surface and a second surface, and the capillary structure is divided into a first part and a second part.

3. The heat pipe structure according to claim 2, wherein the first part contacts the first surface.

4. The heat pipe structure according to claim 3, wherein the first part is connected to the second part.

5. The heat pipe structure according to claim 1, wherein the second region is divided into at least two subspaces.

6. The heat pipe structure according to claim 5, wherein the diameter of each of the subspaces is equal or not equal to that of the first region.

7. The heat pipe structure according to claim 5, wherein the diameters of the subspaces are equal or not equal.

8. The heat pipe structure according to claim 1, wherein the capillary structure is metal sinters, micro grooves, fibers, mental nets or the combinations thereof.