JPH0419341Y2 - - Google Patents

Description

[Detailed explanation of the idea] This invention relates to heat pipes.

As is well known, heat pipes are equipped with a pipe consisting of a metal net or narrow grooves inside the tubular body that forms the exterior body, and after removing non-condensable gases such as air inside the tubular body, water and ammonia are removed. A structure in which a working fluid such as the like is sealed, and the working fluid repeatedly evaporates and condenses to circulate and flow inside the tubular body from one end to the other.
It transports heat as latent heat of the working fluid.
Therefore, the apparent thermal conductivity of the heat pipe is several tens to hundreds of times higher than that of copper, which is the metal with the highest thermal conductivity, and exhibits extremely excellent thermal conductivity.

The distance over which heat can be transported by such a heat pipe is limited by the capillary pressure generated in the heat pipe and the flow resistance of the liquid-phase working fluid within the heat pipe, but the distance between two points at the same height or from a low position to a high When transporting heat towards a location, it can be transported over a fairly long distance. By the way, when heat is transferred from one location to another using a heat pipe, the heat conduction path may have to be bent due to design requirements. If the pipes were to be connected through an appropriate repeater, not only would the overall configuration become complicated, but there would also be a risk of heat transfer loss occurring in the repeater.Therefore, it is desirable to use flexible heat pipes. It can be done. A flexible heat pipe has the advantage that in addition to being able to freely set the heat conduction path, either the heating source or the heat absorption source can be moved freely.

However, conventional heat pipes generally have a structure in which a metal straight pipe is used as an exterior body, which makes it difficult to create a flexible heat pipe. In other words, in order to impart flexibility, it is necessary to reduce the wall thickness of the straight pipe that forms the exterior body, but if the straight pipe is thinned beyond a certain level, local I felt so constricted,
There is a problem that it becomes useless as a heat pipe.

Furthermore, heat pipes in which the exterior body is made of a metal corrugated pipe have been proposed, and this type of heat pipe can be made into a flexible heat pipe. However, since the inner circumferential surface of a heat pipe with a Holgate pipe as an exterior body is also wavy, it is difficult to attach a heat pipe to the inside of the corrugated pipe, especially when the heat pipe is curved. In order to keep it in close contact with the circumferential surface, there were problems such as the need for an appropriate presser to hold down the wick.

On the other hand, when heating or cooling various chemicals through heat pipes, for example, it is desirable to have the heat pipes and chemicals in direct contact in order to improve the heat transfer coefficient, but conventional heat pipes Since the exterior body is made of metal and has poor chemical resistance, there was a problem that it could not be brought into direct contact with chemicals.

In order to solve these problems related to flexibility and chemical resistance, it is conceivable to configure the exterior body with a tubular body made of synthetic resin. However, synthetic resins that are practical in terms of mechanical strength and price have at least a slight gas permeability, and the interior of the heat pipe is set to a high degree of vacuum.
When the exterior body is simply a synthetic resin tubular body,
A problem arises in that non-condensable gas such as air enters the interior and the heat transport properties deteriorate.

This idea was made in view of the above circumstances, and the purpose is to provide a heat pipe with excellent flexibility and chemical resistance. The exterior body for the purpose of
The heat pipe is constructed from a flexible tubular body made of synthetic resin on which a 100 μm thin metal film is formed, thereby making the heat pipe as a whole flexible.

This idea will be explained in more detail below.

As shown in FIG. 1, the heat pipe of this invention includes an exterior body 1, a heat pipe 2 provided inside the exterior body 1, and
It is composed of a working fluid sealed within the exterior body 1. The exterior body 1 is made of a flexible tubular body made of synthetic resin.
Made of ~6mm thick synthetic resin such as polyolefin, polyamide, vinyl chloride resin, fluorine resin, etc.
It is formed of a pipe 3 that is used in a temperature range of 100° C. or lower and has a wall thickness that allows it to easily bend. As shown in FIG. 2, on the inner peripheral surface of the pipe 3,
A metal thin film 4 is formed. The metal thin film 4
Since the pipe 3 is made of synthetic resin,
It is used to reduce gas permeability and moisture permeability to zero, and is made of copper, aluminum, iron, lead, nickel, etc., and has a thickness of 5 to 100 μm.
is set to . In other words, if it is thinner than 5μm,
It is difficult to maintain good gas permeability and moisture permeability over a long period of time, and if the thickness exceeds 100 μm, the resistance to bending of the exterior body 1 increases, and when the exterior body 1 is bent, There is a risk of peeling or cracking. Further, as a method for forming such a metal thin film 4, a vacuum evaporation method is preferable, and other methods such as a sputtering method and an ion plating method can be employed.

On the other hand, the wick 2 is made of a flexible material such as a metal net. Note that the wick 2 may be a narrow groove formed in the inner circumferential surface of the exterior body 1.

As explained above, according to this invention, the entire inner peripheral surface of the flexible tubular body made of synthetic resin has a thickness of 5 to 100 μm.
The exterior body is constructed by forming a thin metal film with a thickness of In addition, by forming a metal thin film on the inner peripheral surface of the tubular body that makes up the exterior body, the gas permeability of the exterior body can be reduced to zero, resulting in a heat pipe that will not crumble over a long period of time and deteriorate its heat transport properties. Obtainable.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional perspective view showing an embodiment of this invention, and FIG. 2 is a partially enlarged sectional view of its exterior body. 1...Exterior body, 2...Wick, 3...(synthetic resin) pipe, 4...Metal thin film.

Claims (1)

[Scope of utility model registration request] A thin metal film with a thickness of 5 to 100 μm is formed on the entire inner peripheral surface of a flexible tubular body made of synthetic resin to form an exterior body, and a wick is provided inside the exterior body, and a A flexible heat pipe characterized by enclosing a working fluid.