HEAT PIPE

Abstract

A heat pipe includes a casing and a supporting member. The casing is made of titanium and has a first end and a second end at two opposite sides thereof. The first end defines a receiving space therein. The supporting member is made of a material selected from one of copper, aluminum, stainless steel, low-carbon steel, iron, nickel, tungsten, tantalum, molybdenum, rhenium and columbium. The supporting member is received in the receiving space of the first end of the casing. The first end of the casing and the supporting member are integrally cramped and sealed.

Description

BACKGROUND

1. Technical Field

The present invention relates generally to a heat pipe, and particularly to a heat pipe which has a pipe body made of titanium and a sealed end made of at least a ductile metal.

2. Description of Related Art

Heat pipes have excellent heat transfer performance due to their low thermal resistance, and are therefore an effective means for transfer or dissipation of heat from heat sources. Currently, heat pipes are widely used for removing heat from heat-generating components such as central processing units (CPUs) of computers. A heat pipe is usually a vacuum casing containing therein a working medium, which is employed to carry, under phase transitions between liquid state and vapor state, thermal energy from one section of the heat pipe (typically referring to as the “evaporator section”) to another section thereof (typically referring to as the “condenser section”).

Presently, titanium is preferred for use as a material to make heat pipes than copper due to its light weight, high strength and high resistance to corrosion. However, titanium has a greater rigidity than copper, whereby cracks would be incurred on a sealed end of the titanium heat pipe when an open end of the heat pipe is cramped to form the sealed end. Thus, a vacuum degree of the heat pipe would be gradually decreased due to the cracks of the heat pipe.

Therefore, it is desirable to provide a heat pipe which can overcome the above described shortcoming.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the present embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

FIG. 1 is an isometric view of a heat pipe in accordance with an exemplary embodiment of the present invention.

FIG. 2 is a longitudinally cross-sectional view of the heat pipe of FIG. 1, taken along line II-II thereof.

FIG. 3 is an enlarged view of a circle portion III of FIG. 2.

DETAILED DESCRIPTION

Referring to FIGS. 1-2, a heat pipe 1 includes a sealed casing 10 containing a working fluid (not shown) therein, a wick structure 12 disposed on an inner surface of the casing 10 and a supporting member 16 received in the casing 10.

The casing 10 is made of titanium. The casing 10 has a first end 13, a second end 14 opposite to the first end 13 of the casing 10, and a middle main portion 15 between the second end 14 and the first end 13. The first end 13 defines a receiving space 136 therein. The first end 13 includes a shrinkage portion 131 connecting with the middle main portion 15 of the casing 10, a connecting portion 132 connecting with the shrinkage portion 131 and a sealing portion 133 connecting with the connecting portion 132. The shrinkage portion 131 has a tapered configuration and an outer diameter of the shrinkage portion 131 gradually decreases along an axial direction from the second end 14 of the casing 10 toward the first end 13 of the casing 10. The connecting portion 132 has a tube-shaped configuration and extends longitudinally outwardly from the shrinkage portion 131. The sealing portion 133 is flat and has a top wall 134 and a bottom wall 135 spaced from each other.

The supporting member 16 is made of a material with low rigidity and good ductility such as copper, aluminum, stainless steel, low-carbon steel, iron, nickel, tungsten, tantalum, molybdenum, rhenium and columbium. In the preferred embodiment, the supporting member 16 is made of copper.

The supporting member 16 is received in the receiving space 136 of the first end 13 of the casing 10. An outer circumferential surface of the supporting member 16 is tightly attached to an inner circumferential surface of the first end 13 of the casing 10. The supporting member 16 includes a positioning portion 161 corresponding to the shrinkage portion 131 of the casing 10, a tube-shaped connecting portion 162 corresponding to the connecting portion 132 of the casing 10 and a flat sealing portion 163 corresponding to the sealing portion 133 of the casing 10. The positioning portion 161 and the sealing portion 163 are disposed at two opposite ends of the supporting member 16. The connecting portion 162 is disposed between the positioning portion 161 and the sealing portion 163 of the supporting member 16.

The positioning portion 161 has a tapered configuration and an outer diameter of the positioning portion 161 gradually decreases along an axial direction from the second end 14 of the casing 10 toward the first end 13 of the casing 10. An outer circumferential surface of the positioning portion 161 of the supporting member 16 is tightly attached to an inner circumferential surface of the shrinkage portion 131 of the casing 10. The connecting portion 162 of the supporting member 16 has an outer diameter the same as an inner diameter of the connecting portion 132 of the casing 10. An outer circumferential surface of the connecting portion 162 of the supporting member 16 is tightly attached to an inner circumferential surface of the connecting portion 132 of the casing 10. An outer circumferential surface of the sealing portion 163 of the supporting member 16 is tightly attached to an inner circumferential surface of the sealing portion 133 of the casing 10.

The sealing portion 133 of the casing 10 is cramped to form the top wall 134 and the bottom wall 135, whereby the sealing portion 163 of the supporting member 16 is cramped to form a top wall 164 and a bottom wall 165 intimately connected to the top wall 164. A free end 137 of the sealing portion 133 of the casing 10 and a free end 167 of the sealing portion 163 of the supporting member 16 are connected and sealed together by welding.

In manufacturing the heat pipe 1, the casing 10 is provided, with the second end 14 of the heat pipe 1 being integrally sealed and the first end 13 being open. Then, the supporting member 16 is provided and inserted into the receiving space 136 of the first end 13 of the casing 10. The first end 13 is shrunk to form the shrinkage portion 131 and the connecting portion 132. The positioning portion 161 and the connecting portion 162 of the supporting member 16 are accordingly formed. The shrinkage portion 131 of the casing 10 prevents the supporting member 16 from moving longitudinally outwardly. The sealing portion 133 of the casing 10 is cramped to cause the sealing portion 133 of the casing 10 and the sealing portion 163 of the supporting member 16 to be flattened, whereby the top wall 163 and the bottom wall 164 of the sealing portion 163 of the supporting member 16 are intimately connected together. Finally, the free end 137 of the sealing portion 133 of the casing 10 and the free end 167 of the sealing portion 163 of the supporting member 16 are welded, so that the heat pipe 1 is hermetically sealed. When the sealing portion 133 of the casing 10 is cramped, the sealing portion 133 is prevented from cracking since the supporting member 16, which is made of a material having a low rigidity and good ductility in comparison with titanium supports the sealing portion 133 of the casing 10. Thus, the heat pipe 1 can have a better hermetically sealing effectiveness, in comparison with that attainable by a heat pipe purely made of titanium. It is well known by those skilled in the art that before the cramping of the sealing portions 133, 163 of the casing 10 and the supporting member 16, the working fluid is injected into the casing 10 and the air in the casing 10 is vacuumed via a hole in the sealing portion 163.

It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.

Claims

1. A heat pipe comprising:

a casing made of titanium and having a first end and a second end at two opposite sides thereof, the first end defining a receiving space therein; and

a supporting member being made of a material selected from one of copper, aluminum, stainless steel, low-carbon steel, iron, nickel, tungsten, tantalum, molybdenum, rhenium and columbium, the supporting member being received in the receiving space of the first end of the casing, the first end of the casing and the supporting member being integrally cramped and sealed.

2. The heat pipe as claimed in claim 1, wherein an inner peripheral surface of the first end is tightly attached to an outer peripheral surface of the supporting member.

3. The heat pipe as claimed in claim 1, wherein the first end comprises a shrinkage portion and a sealing portion at two opposite ends thereof, the shrinkage portion has a tapered configuration and an outer diameter of the shrinkage portion gradually decreases along an axial direction from the second end of the casing toward the first end of the casing.

4. The heat pipe as claimed in claim 3, wherein the supporting member comprises a positioning member corresponding to the shrinkage portion of the casing and a sealing portion corresponding to the sealing portion of the first end of the casing, the sealing portion of the supporting member is flat and has a top wall and a bottom wall intimately connected to the top wall.

5. The heat pipe as claimed in claim 4, wherein a free end of the sealing portion of the first end of the casing and a free end of the sealing portion of the supporting member are connected and sealed together by welding.

6. The heat pipe as claimed in claim 1 further comprising a wick structure disposed in the heat pipe and working fluid contained in the heat pipe.

7. A heat pipe, comprising:

a casing made of titanium and having a first end and a second end at two opposite sides thereof, the first end defining a receiving space therein; and

a supporting member made of a material different from titanium, the supporting member being received in the receiving space of the first end of the casing, the first end of the casing and the supporting member being integrally cramped and sealed.

8. The heat pipe as claimed in claim 7, wherein the supporting member is made of a material selected from the group consisting of copper, aluminum, stainless steel, low-carbon steel, iron, nickel, tungsten, tantalum, molybdenum, rhenium and columbium.

9. The heat pipe as claimed in claim 8, wherein an outer peripheral surface of the supporting member is tightly attached to an inner peripheral surface of the first end of the casing.

10. The heat pipe as claimed in claim 9, wherein the first end of the casing comprises a shrinkage portion and a sealing portion at two opposite ends thereof, the shrinkage portion has a tapered configuration and an outer diameter of the shrinkage portion gradually decreases along an axial direction from the second end of the casing toward the first end of the casing.

11. The heat pipe as claimed in claim 10, wherein a free end of the sealing portion of the casing and a free end of the sealing portion of the supporting member are connected and sealed together by welding.

12. The heat pipe as claimed in claim 7 further comprising a wick structure disposed in the heat pipe and working fluid contained in the heat pipe.

13. The heat pipe as claimed in claim 12, wherein the supporting member is made of copper.