Heat Sink Structure

Description

FIELD OF THE INVENTION

The present invention relates to a heat sink structure, and more particularly to a heat sink structure consisting of a heat dissipating body made of a heat-conducting plastic material and a heat pipe made of a metal material to thereby have reduce weight and material cost while providing good heat dissipating effect.

BACKGROUND OF THE INVENTION

Various kinds of electronic information products, such as computers, have become very popular among consumers and been widely applied in many different fields. Consumers' demands bring prosperous development in the electronic information industry, and all the currently commercially available electronic information products have increasingly upgraded computing speed and expanded access capacity. As a result, a high amount of heat is also produced by the electronic elements in the electronic information products when they operate at high speed.

A light emitting diode (LED) emits cold light, and has the advantages of low power consumption, energy-saving, long service life, low pollution, no idling time, fast response speed, and high efficiency. Therefore, street lights or other lighting fixture related thereto that are usually required to provide higher illuminance will adopt high-power LEDs as their light source. By supplying higher current to the LED, a relatively high illuminance can be obtained.

However, while the high-current LED provides increased illuminance, the heat produced by the LED is inevitably increased, too. The produced high amount of heat must be timely removed, lest the heat should accumulate around the LED to cause lowered lighting efficiency and even shortened LED service life. There are many electronic apparatuses that use LEDs as a main light source thereof. However, all these electronic apparatuses have the same problem of having relatively poor heat dissipation efficiency, which adversely results in burned-out apparatus due to overheating, increased light wane and shortened service life.

FIGS. 1 and 2 are perspective and sectional views, respectively, of a conventional heat sink structure 1, which has a heat dissipating body 11 made of aluminum or other single type of metal material. The heat dissipating body 11 is configured as a hollow cylindrical member with a plurality of radiating fins 12 radially extended from an inner and an outer wall surface thereof. The radiating fins 12 are also formed with one single type of metal material the same as the heat dissipating body 11 and are integrally formed with the heat dissipating body 11. Since both of the heat dissipating body 11 and the radiating fins 12 are made of a metal material, the heat sink structure 1 requires relatively high material cost and is relatively heavy, which form limitations in the applicability of the heat sink structure 1.

When the heat sink structure 1 is used to remove the heat produced by an LED module, the LED module is assembled to one end of the heat dissipating body 11, so that heat produced by the LED module is absorbed by the heat dissipating body 11 and dissipated into ambient air via the heat dissipating body 11 and the radiating fins 12. With the heat dissipating body 11 and the radiating fins 12 being made of the same single type of metal material, the heat sink structure 1 provides relatively low heat conductivity and fails to effectively transfer the heat produced by the LED module from the end of the heat dissipating body 11 with the LED module to the other end of the heat dissipating body 11 that has a relatively low temperature.

In brief, the conventional heat sink structure 1 has the following disadvantages: (1) low heat conductivity; (2) high material cost; and (3) heavy in weight.

It is therefore tried by the inventor to develop an improved heat sink structure to overcome the above disadvantages.

SUMMARY OF THE INVENTION

A primary object of the present invention is to provide a heat sink structure that has a plastic heat dissipating body with a heat pipe: embedded therein to provide high thermal conductivity and good heat dissipating efficiency.

Another object of the present invention is to provide a heat sink structure that has reduced overall weight compared to conventional heat sink structures of similar types.

A further object of the present invention is to provide a heat sink structure that can be manufactured with reduced material cost compared to conventional heat sink structures of similar types.

To achieve the above and other objects, the heat sink structure according to a preferred embodiment of the present invention includes a heat dissipating body and at least one heat pipe. The heat dissipating body includes a main body having two opposite first and second end faces, and a plurality of radiating fins formed on two opposite wall surfaces of the main body to axially extend between the first and the second end face. The heat dissipating body is made of a heat-conducting plastic material through injection molding, and the heat pipe is embedded in the heat dissipating body during the process of injection molding the heat dissipating body. The heat pipe has a first and a second end respectively exposed from the first and second end faces of the heat dissipating body for directly contacting with a heat source, and a pipe body helically extended between the first and the second end and embedded in the heat dissipating body.

With the heat dissipating body made of a heat-conducting plastic material through injection molding and the heat pipe helically embedded in the plastic heat dissipating body, the heat sink structure of the present invention not only provides high thermal conductivity and good heat dissipating effect, but also has reduced weight and material cost.

BRIEF DESCRIPTION OF THE DRAWINGS

The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein

FIG. 1 is a perspective view of a conventional heat sink structure;

FIG. 2 is a perspective sectional view of the heat sink structure of FIG. 1;

FIG. 3 is a perspective view of a heat sink structure according to the present invention;

FIG. 4 is a perspective sectional view of the heat sink structure of FIG. 3;

FIG. 5 shows the heat sink structure of the present invention in use;

FIG. 6 is a perspective sectional view of FIG. 5; and

FIG. 7 is a side view of FIG. 5.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Please refer to FIGS. 3 and 4. A heat sink structure according to a preferred embodiment of the present invention includes a heat dissipating body 2 and a heat pipe 3. The heat dissipating body 2 is made of a plastic material through injection molding, and can be molded into various shapes depending on actual need. The plastic material for molding the heat dissipating body 2 is a heat-conducting material selected from the group consisting of Ethylon (UPE), polyoxymethylene (POM), polyethylene terephthalate (PETP), nylon, polypropylene (PP), polyethylene (PE), polyvinylidene fluoride (PVDF), Teflon (polytetrafluoroethylene or PTFE), polyvinyl chloride (PVC), Acrylonitrile Butadiene Styrene (ABS), tempered glass, polyether polyols (PES), acrylic (polymethylmethacrylate or PMMA), poly(ether-ether-ketone) (PEEK), and poly(amide-imide) (PAI).

In the illustrated embodiment of the present invention, the heat dissipating body 2 is injection molded into a hollow cylinder including a main body 21 and a plurality of radiating fins 24. The main body 21 has a first end face 22 and a second end face 23 opposite to the first, end face 22, both of which are a plane surface. The radiating fins 24 are formed on an inner and an outer wall surface of the main body 21 to axially extend between the first and the second end face 22, 23. The radiating fins 24 are also formed of a plastic material through injection molding. The heat pipe 3 is embedded in the heat dissipating body 2 during the process of injection molding the heat dissipating body 2, and includes a first end 31, a second end 33, and a pipe body 32 extended between the first and the second end 31, 33.

In the illustrated embodiment, the pipe body 32 of the heat pipe 3 is helically extended between the first and the second end 31, 33. The first and the second end 31, 33 of the heat pipe 3 are located at and exposed from the first and the second end face 22, 23 of the heat dissipating body 2, respectively. While the heat dissipating body 2 is made of a plastic material through injection molding, the heat pipe 3 is made of a metal material, such as copper. In other words, for the heat pipe 3 to be embedded in the heat dissipating body 2, the material selected for the heat dissipating body 2 should have a melting point lower than that of the material for the heat pipe 3. In the illustrated preferred embodiment, the heat dissipating body 2 is made of a plastic material. However, it is understood, in practical implementation of the present invention, the heat dissipating body 2 is not necessarily made of a plastic material but can be made of other suitable materials.

Please refer to FIGS. 5, 6 and 7 at the same time. The heat dissipating body 2 can be associated with an LED module 4. The LED module 4 can be attached to either the first end face 22 or the second end face 23 of the heat dissipating body 2. In the illustrated embodiment, the LED module 4 is attached to the second end face 23 of the heat dissipating body 2 and accordingly contacts with the second end 33 of the heat pipe 3 exposed from the second end face 23. When the LED module 4 produces heat during the operation thereof, the produced heat is directly absorbed by the second end 33 of the heat pipe 3 and then transferred via the pipe body 32 to the first end 31. Since the first end 31, the pipe body 32, and the second end 33 of the heat pipe 3 are embedded in the heat dissipating body 2, the heat absorbed by the second end 33 and transferred to the pipe body 32 and the first end 31 of the heat pipe 3 can also be quickly transferred to the heat dissipating body 2 to dissipate into ambient environment. That is, the heat sink structure of the present invention can advantageously provide high efficient thermal conduction. With the heat pipe 3 made of a metal material embedded in the heat dissipating body 2 made of a heat-conducting plastic material, heat absorbed by the heat pipe 3 can be more effectively guided away from the LED module 4 and dissipated into air, and the heat sink structure can have reduced overall weight and be manufactured at reduced material cost.

In brief, the heat sink structure of the present invention has the following advantages: (1) having high thermal conductivity; (2) requiring only reduced material cost; and (3) being light in weight.

The present invention has been described with a preferred embodiment thereof and it is understood that many changes and modifications in the described embodiment can be carried out without departing from the scope and the spirit of the invention that is intended to be limited only by the appended claims.