JPS60251390A - Manufacture of heat pipe - Google Patents

Abstract

PURPOSE:To bond wick to an envelope strongly without changing the porosity of the wick by a method wherein the powder, which becomes the material of the wick, and binding powder are loaded into the envelope and the envelope is heated locally under being rotated. CONSTITUTION:The material powder 2, consisting of copper pieces having the grain size of 200 mesh or less, and the fine binding powder 3 of low melting solder having the grain size of 500 mesh substantially are mixed in the envelope 1 consisting of a copper tube. The envelope is rotated under being kept in horizontal. Then, a heater 4, located at the outside of the envelope 1, is moved from one end to the other end of the envelope 1 sequentially to heat and bond the powders. Thus, the outer peripheral portion of the material powder 2 is bonded to the inner wall of the envelope 1 by welding strongly through the fine bonding powder 3 under keeping uniform porosity of the wick.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a method for manufacturing a heat pipe.

Conventional structure and its problems A heat pipe consists of a porous wick arranged along the inner wall of a metal envelope with high thermal conductivity, a working liquid serving as a heat medium sealed inside, and a heat pipe at both ends of the pipe. It is common that the tank is closed and the internal pressure is reduced.

When heat is applied to one end of the pipe, the working liquid evaporates due to the heat of vaporization, moves to the other end, dissipates the heat and condenses, moves through the wick through capillary action, returns to its original state, and evaporates again. heat transfer.

In the above process, vaporization heat absorption during evaporation of the working liquid and latent heat release during condensation are performed via the envelope and the wick. Therefore, the heat transfer efficiency is greatly influenced by the degree of bonding between the envelope and the wick.

Conventionally, the envelope and the wick have been bonded by a diffusion bonding method by heating in a heating furnace to mJ at which diffusion starts. However, this method has the problem that it takes time to heat the entire pipe to complete joining, and that it is a batch method, which is poor in productivity.

In addition, when metal powder is used as the wick material, heating to the bonding temperature may cause sintering of the metal powder, change in porosity due to shrinkage, and peeling from the envelope. Therefore, it is difficult to obtain a stable bond.

Purpose of the Invention The object of the present invention is to eliminate the above-mentioned drawbacks of the conventional method and to use continuous partial heating to ensure that fine bonding powder has a uniform porosity and is bonded to the inner wall of the envelope. It is.

Structure of the Invention In order to achieve the above-mentioned object, the present invention comprises mixing a material powder serving as a wick material and a fine bonding powder for bonding in a predetermined ratio in advance, and then placing the mixture in an envelope. It heats the outside in sequence while rotating.

DESCRIPTION OF EMBODIMENTS Next, an embodiment of the present invention will be described with reference to FIGS. 1 to 3. 1 is an envelope made of steel pipe, inside which
Material powder 2 consisting of copper pieces of 200 meshes or less, and
Fine powder bonding powder of low fusion solder of about 500 mesosh 3
As such, they are mixed at the same time. Then, the material powder 2 and the fine bonded powder 3 enclosed in the envelope 1 are
Rotate the envelope 1 in the circumferential direction while keeping it horizontal to the extent that it does not spill. Then, the heater 4 located outside the envelope 1 is sequentially moved from one end of the envelope 1 to the other to heat and weld the envelope 1.

Therefore, the inner wall of the envelope 1 and the outer periphery of the material powder 2 are strongly welded and joined by the fine bonding powder 3.

Furthermore, the welding depth depends on the surface roughness and cleanliness of the envelope 1 and material powder 2, but can be easily adjusted as necessary by adjusting the heat capacity and moving speed of the heater 4. can.

Effects of the Invention As is clear from the above embodiments, the present invention produces fine powder by simultaneously mixing a fine powder bonded body to become a wick and material powder into an envelope, rotating the envelope, and performing partial heating. The fine bonded powder can be strongly bonded to the envelope without changing the porosity of the bonded powder, and the bonding work can be done not only instantaneously but also continuously, resulting in high productivity. Improving dramatically.

Moreover, the obtained heat pipe can have very high heat transfer efficiency.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a heat pipe according to an embodiment of the present invention, FIG. 2 is a partial sectional view of the inside of an envelope during heating, and FIG. 3 is a partially enlarged sectional view of FIG. 1. 1... Envelope, 2... Fine bonded powder, 3... Bonded powder, 4... Heater, 6... Melting Part/Name of agent Patent attorney Toshio Nakao and 1 other person 1st
Figure 3

Claims (1)

[Claims] In a predetermined space within an envelope, a material powder and a fine bonded powder that is made by welding the material powder into the envelope and become a wick are mixed, and the material is mixed in a predetermined space while rotating the envelope. A method for forming a heat pipe, which is characterized in that an envelope and a fine bonded powder are brought into bath contact by heating.