JPH0571871B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a heat pipe that can be used for cooling electrical equipment.

BACKGROUND TECHNOLOGY It is well known that in various electrical devices, temperature rises due to energization lead to capacity limitations and deterioration of characteristics. Air cooling is performed via heat pipes. FIG. 5 shows an example of a conventional cooling structure, in which a plurality of thyristors 1 are clamped with a heat receiving block 2 sandwiched between them, applying a load from both sides, and each heat receiving block 2 has a heat dissipating block. One end (generally the lower end) of the heat pipe 4 with the fin 3 attached is inserted, and an insulating plate 5 is inserted between the thyristor 1 and the heat receiving block 2 because the heat pipe 4 uses a metal tube as a container.
is mediated. Therefore, the heat generated in the thyristor 1 is transported by the heat pipe 4 as the latent heat of its working fluid, and then transferred from the radiation fins 3 to the surrounding air, and as a result, the thyristor 1 is indirectly cooled by air. .

However, although the purpose of the insulating plate 5 is electrical insulation, the thyristor 1 is clamped by applying a load from both sides, so in order to increase the compressive strength of the insulating plate 5, the insulating plate 5 is expensive. There is a problem that a material must be used, otherwise the insulating plate 5 must be thick. Furthermore, in order to perform efficient cooling, it is desirable to reduce the heat transfer resistance from the thyristor 1 to the air as much as possible. This impedes heat exchange between the plates, and if the thickness of the plate is increased, there is a problem that heat transfer will further deteriorate.

Conventionally, in order to eliminate such inconveniences, heat pipes with electrical insulation properties have been developed, examples of which are described in Japanese Patent Application Laid-open No. 56-108098 and Japanese Utility Model Application No. 57-19778. has been done. As shown in FIG. 6, the heat pipe described in the former publication has an insulator made of an insulating material such as ceramic between the metal tube 6 inserted into the heat receiving block 2 and the metal tube 7 to which the heat dissipation fin 3 is attached. The structure is such that a pipe 8 is interposed, and the pipe and working fluid are insulated. The latter heat pipe uses glass fiber in the middle part and metal fibers in both ends as a wick inside a container with an insulating tube interposed in the middle part, and these fibers are connected by spiral springs. It has a fixed configuration.

Problems to be Solved by the Invention However, the heat pipes described in the above-mentioned publications have an insulating tube made of ceramic or the like, so they have excellent electrical insulation as a whole. Since tubes are made of highly brittle materials, insulating tubes are easily damaged when subjected to vibrations or shocks, and thermal expansion coefficients are significantly different between insulating tubes and metal tubes, resulting in thermal stress. There were problems such as reduced durability of the joint between the two due to thermal shock.

It is an object of the present invention to solve the above-mentioned problems and provide an electrically insulated heat pipe that can absorb external force and thermal stress and therefore has good durability.

Means for Solving the Problems In order to achieve the above object, the present invention provides a sleeve made of an insulating material interposed in an intermediate portion to impart insulation to a sealed tube, and at least one metal pipe adjacent to the sleeve. and the sleeve are in a non-adhered state, and the sleeve and the metal pipe are connected by a connecting pipe made of a metal material having a coefficient of thermal expansion approximately equal to that of the sleeve and configured to be elastically deformable. be. More specifically, the present invention constructs a closed container by interposing a sleeve made of an insulating material between a first metal tube serving as a heating section and a second metal tube serving as a heat radiating section; In the heat pipe, the sleeve and at least one of the metal pipes are in a non-adhesive state, and the sleeve and the metal pipe are heated to approximately the same temperature as the sleeve. It is characterized in that it is connected by a connecting tube that is elastically deformable and made of a metal material with a high coefficient of expansion.

Further, in the present invention, the connecting pipe is configured as an annular body having a U-shaped cross section at the peripheral portion and having an inner circumferential lip portion and an outer circumferential lip portion, one of the lip portions is joined to the metal tube, and The other lip portion may be joined to the sleeve.

Function In the heat pipe of the present invention, the internal working fluid is evaporated by the heat applied to the metal pipe that is the heating section, and the vapor flows to the second metal pipe that is the heat radiating section, and then the heat is radiated. This is similar to the conventional insulated heat pipe described above, in that each metal pipe is electrically insulated by a sleeve, but the first metal pipe or If an external force or vibration is applied to the metal pipe No. 2, or if there is a difference in the amount of thermal expansion between the sleeve and each metal pipe, the sleeve and the metal pipes may not be in a fixed state. Since the connecting tube is elastically deformable, the connecting tube deforms to absorb external forces and differences in the amount of thermal expansion, and as a result, damage to the sleeve made of an insulating material is prevented.

Embodiments Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a partial sectional view showing one embodiment of the present invention, and the heat pipe 10 shown here is a first embodiment of the present invention.
An insulating sleeve 13 is interposed between the first metal pipe 11 and the second metal pipe 12, and these metal pipes 11, 12 and the sleeve 13 are connected by a metal connecting pipe 14. A sealed pipe is used as a container. A working fluid is sealed inside, and a wick is provided as necessary. That is, the first
The metal pipe 11 is used as a heating part that receives heat from the outside, and the second metal pipe 12 is used as a heat radiating part that releases heat to the outside.These pipes 11 and 12 are made of copper. It is constructed as a pipe with one end sealed with metal such as. In addition, the sleeve 13 is connected to each metal pipe 11, 12.
It is made of an insulating material such as a ceramic material such as alumina, and its shape is such that the inner diameter of the intermediate part in the axial direction is approximately equal to the inner diameter of each metal pipe 11, 12. Set the inner diameter of both ends of the metal pipe 11,1
2 (hereinafter, this portion will be temporarily referred to as large diameter portion 13a). Each of the metal pipes 11 and 12 has its open end inserted into the inner peripheral side of the large diameter portion 13a of the sleeve 13 in a non-fixed state, and is connected to the sleeve 13 in an airtight state by a connecting pipe 14. This connecting pipe 14
The sleeve 13 is made of a metal material having a coefficient of thermal expansion approximately equal to that of the material of the sleeve 13, such as Kovar or 42Ni-Fe alloy, and is elastically deformable. like,
It is formed into an annular shape with an inner circumferential lip 14a and an outer circumferential lip 14b with a circumferential edge having a U-shaped cross section. The connecting pipe 14 has an inner circumferential lip 14.
By brazing the inner circumferential surface of a to the outer circumferential surface of the metal pipes 11 and 12, and brazing the inner circumferential surface of the outer circumferential lip 14b to the outer circumferential surface of the sleeve 13, each of the metal pipes 11 and 12 and the sleeve 13 are connected. The two are movable relative to each other and connected in an airtight manner. In addition, in the example shown in FIGS. 1 and 2, each metal pipe 1
A gap is set between the sleeve 13 and the ends and outer peripheral surfaces of the sleeves 1 and 12.

Figures 3 and 4 show the heat pipe 10 described above.
This shows an example in which the thyristor 1 is used in a cooling device for a thyristor 1. The thyristor 1 is tightly sandwiched between a pair of heat receiving blocks 2 which are tightened by a clamp fitting 15, and each heat receiving block 2 has a plurality of heat receiving blocks 2. A first metal pipe 11 of each heat pipe 10 is inserted, and a heat radiation fin 16 is attached to a second metal pipe 12 of each heat pipe 10. Therefore, the heat generated by the thyristor 1 is transferred from the heat receiving block 2 to the heat pipe 10, so by flowing cooling air to the second metal pipe 12 side of the heat pipe 10, the heat pipe 10 is transferred to the first metal pipe 12. The metal pipe 11 side of the thyristor 1 becomes a heating section, and the second metal pipe 12 side becomes a heat dissipation section, and heat is transferred between the two.In the end, the heat generated in the thyristor 1 is transferred to the cooling air via the heat pipe 10. Thus, the thyristor 1 is air-cooled. When an external force is applied to the second metal pipe 12 side or vibration acts on the whole, in the heat pipe 10 described above, the connecting pipe 1
4 is bent, for example, as shown by the chain line in FIG. 2, external forces and vibrations are absorbed as deformation of the connecting pipe 14, and as a result, the highly brittle sleeve 13 can be prevented from being damaged. Further, when a difference in thermal expansion occurs between the sleeve 13 and the metal pipes 11 and 12, the connecting pipe 14 is bent in accordance with the difference, so that no excessive thermal stress is applied to the sleeve 13.
Therefore, even in this case, damage to the sleeve 13 can be prevented.

In the above embodiment, the case where the connecting pipe 14 is formed as an annular body having a U-shaped cross section at the peripheral part is explained as an example, but the connecting pipe in this invention is essentially shaped to be elastically deformable. Any configuration is sufficient, and the configuration is not limited to the configuration shown in the above embodiment. Further, in the above embodiment, the first metal pipe 11 and the second metal pipe 12 and the sleeve 1
3, but this invention is not limited to the above embodiment, and if only external force needs to be taken into consideration, connecting pipes between the sleeve and either A connecting pipe 14 may be interposed between the metal pipe and the metal pipe.

Effects of the Invention As is clear from the above description, according to the heat pipe of the present invention, the electrically insulating sleeve and the metal pipe are made of a metal material having approximately the same coefficient of thermal expansion as the sleeve and are elastically deformable. Because they are connected by a connecting pipe, external forces, vibrations, or thermal stress can be absorbed as deformation of the connecting pipe, so excessive stress is not generated in the sleeve or the connection between the sleeve and the metal pipe. Therefore, according to this invention, there is less risk of damage;
Moreover, an electrically insulated heat pipe with excellent durability can be obtained. Furthermore, if the heat pipe of the present invention is used as a heat dissipation means for high-voltage electrical equipment, there is no need to interpose an insulating material between the heat pipe and the high-voltage electrical equipment, so it is possible to obtain a heat radiator that is inexpensive and has good heat dissipation efficiency. .

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing an embodiment of the present invention, FIG. 2 is an enlarged sectional view of the vicinity of the sleeve,
Fig. 3 is a front view of an example in which the heat pipe is used as a thyristor heatsink, Fig. 4 is a side view thereof, Fig. 5 is a schematic diagram showing an example of a conventional heat pipe type thyristor heatsink, and Fig. 6 1 is a schematic diagram showing a thyristor heat sink using a conventional electrically insulated heat pipe. DESCRIPTION OF SYMBOLS 10...Heat pipe, 11, 12...Metal pipe, 13...Sleeve, 14...Connecting pipe, 14a...Inner circumference lip, 14b...Outer circumference lip.

Claims (1)

[Claims] 1. A hermetic container is constructed by interposing a sleeve made of an insulating material between a first metal tube serving as a heating section and a second metal tube serving as a heat radiating section, and In a heat pipe in which a working fluid is sealed inside a container, the sleeve and at least one of the metal pipes are in a non-adhesive state, and the sleeve and the metal pipe have a coefficient of thermal expansion that is approximately equal to that of the sleeve. An electrically insulated heat pipe characterized in that it is connected by a connecting pipe made of a metal material and configured to be elastically deformable. 2. The connecting pipe is configured as an annular body with a U-shaped cross section having an inner peripheral lip portion and an outer peripheral lip portion at the peripheral portion, one lip portion of which is joined to the metal tube, and the other lip portion is connected to the metal tube. 2. The electrically insulated heat pipe according to claim 1, wherein said heat pipe is connected to said sleeve.