JPH03175291A - Method of burying and fixing heat pipe - Google Patents

Abstract

PURPOSE:To enable a simple and positive filling and fixing of a heat pipe into a hole to be attained by a method wherein a closed end of the hole is placed at a lower side, a filling agent is fed at a bottom part of the hole, the heat pipe is inserted into the hole, thereafter a vacuum drawing device which has a weight of predetermined weight axially movable and will be removed afterwards is fixed to an opening end of the hole through a vacuum seal and after fixing the filling agent is heated while drawing vacuum within the hole for a predetermined period of time and then solidified. CONSTITUTION:A hollow steel shaft 8 having one closed end is placed vertically, a proper amount of solder 3a is fed to a bottom part of a hole and after inserting a heat pipe 4, a vacuum drawing device 6 having a weight 5 freely slidable axially in it is fixed to an upper end opening through a vacuum seal 7. An electrical heater 10 is fixed to an outer part near a lower end of the hollow steel shaft 8 and an entire assembly is covered by a thermal insulating agent 11. A vacuum pump 9 is operated, an input is applied to the electrical heater 10 and kept at a specified temperature higher than a solder melting temperature, resulting in that the solid solder is lifted up in a clearance between the hollow steel shaft 8 and the heat pipe 4 and the solvent fills an entire clearance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for embedding and fixing a heat pipe.

[Prior technology] To reduce the thermal resistance between the heat pipe and the heat transfer body outside it and to fix the heat pipe, fillers such as molten solder or epoxy resin are used as fillers that have temporary fluidity and can be solidified later. A commonly used method is to insert a filler into the bottom of the hole and then insert a heat pipe. An example is shown in FIG.

As shown in the figure, a hole 2 with a closed bottom is formed in the heat transfer body 1, and a filler 3 is placed in the bottom with the open side facing up. By inserting the pipe 4 in the direction of the arrow in the figure, the gap between the heat pipe 4 and the heat transfer body 1 is filled with the filler 3, and later the filler 3 is solidified to complete the filling.

When a low melting point alloy such as solder is used as the filler 3, flux is often used in combination to improve the wettability of the filler 3 to the outer surface of the heat pipe and the inner surface of the hole, and to prevent fluidity from decreasing due to oxidation. (Use of solder containing solder, etc.)

[Problems to be Solved by the Invention] In the above-described conventional technology, it is difficult to remove air bubbles in the filler that fills the gap between the hole and the heat pipe, and it takes considerable effort to remove them sufficiently. When using flux,
Flux may partially remain in the packed bed, impairing the integrity of the packed bed, and may have unfavorable effects on heat transfer and corrosion resistance. Also, flux vapor may be released during the filling process and contaminate the surrounding area. There are also problems. After the implant is complete, excess flux will accumulate on the surface and often needs to be removed.

The present invention has been made in view of the above points, and provides a method for embedding and fixing a heat pipe, which eliminates the drawbacks of the conventional technology and makes it possible to easily and reliably fill and fix a heat pipe into a hole. The purpose is to

[Means for Solving the Problems] The above object is to place the closed end of the hole on the lower side, put a filler in the bottom of the hole, insert the heat pipe into the hole, and then place the heat pipe on the front end side of the hole.
A vacuum suction device, which has a weight of a predetermined weight that is in contact with one end of the heat pipe and is movable in the axial direction, and is removed later, is installed via a vacuum seal, and after installation, the vacuum inside the hole is maintained for a predetermined period of time. This is achieved by heating the filler while drawing and then solidifying it.

[Operation] Since the above means is provided, the weight pushes the heat pipe into the bottom of the hole while heating the filler while vacuuming, and the gap between the heat pipe and the hole is filled with the filler. Then remove the air bubbles and allow it to solidify.

[Example] The present invention will be described below based on the illustrated example. FIG. 1 shows an embodiment of the invention. Note that the same parts as in the past have been given the same arrows, so their explanations will be omitted. In this embodiment, the closed end of the hole 2 is placed at the bottom, the filler is put in the bottom of the hole 2, and the heat pipe 4 is inserted into the hole 2, and then the open end of the hole 2 is brought into contact with one end of the heat pipe 4. , a vacuum device 6 having a weight 5 of a predetermined weight that is movable in the axial direction and which is to be removed later is installed via a vacuum seal 7, and after the installation, while drawing the vacuum inside the hole 2 for a predetermined period of time. The filler was solidified after heating. By doing this, the weight 5 will push the heat pipe 4 into the bottom of the hole 2 while heating the filler while vacuuming, and the filler will fit into the gap between the heat pipe 4 and the hole 2. A method for embedding and fixing a heat pipe 4 that can be filled and solidified by removing air bubbles, eliminates the drawbacks of the conventional technology, and makes it possible to easily and reliably fill and fix a heat pipe 4 into a hole. Obtainable.

That is, the figure shows a method of embedding the heat pipe 4 into the hollow steel shaft 8 using solder 3a as a filler, with (a) showing the initial state after the device has been set up, and (b) showing the completed filling. This is a state in which the second half solder 3a is solidified.

As shown in Figure (a), a hollow steel shaft 8 with one end closed is placed vertically, a suitable amount of solder 3a is put into the bottom of the hole, and after inserting a heat pipe 4, it is placed on the open side of the upper end. , a vacuum device 6 having a weight 5 that can freely slide in the axial direction inside.
is attached via vacuum seal 7. The evacuation device 6 is connected to a vacuum pump 9. An electric heater 10 with adjustable input is attached to the outside near the lower end of the hollow steel shaft 8,
The whole is covered with an easily removable heat insulating material 11.

After assembling the device, the vacuum pump 9 is activated, and the electric heater 10 is activated.
When the solid solder 3a is maintained at a constant temperature higher than the solder melting temperature by applying an input to the temperature, the solid solder 3a gradually melts, and when it is completely melted, the heat pipe 4 is lowered by the weight 5. During this time, the molten solder flows upward through the gap between the hollow steel shaft 8 and the heat pipe 4 and spreads throughout. Since the heat pipe 4 itself has isothermal properties over its entire length, it is sufficient to heat only one end (lower end side) (see figure (b)).The air bubbles in the solder filling the gap are buoyant. Since the solder is discharged with an upper boundary caused by the solder, a filled solder layer with almost no voids can be obtained by heating while being evacuated for a predetermined period of time.

Furthermore, since the solder 3a forms oxides when heated in the atmosphere, it is necessary to use flux in combination to obtain a healthy packed layer, but the method of the present invention has the great advantage of not requiring flux. (For example, in the case of PB-SNN co-ed soldering, rosin is used as a flux, but it emits smoke during melting and it is difficult to remove anything that gets into the gaps.There are practical problems such as the need to remove excess flux later.) )
After filling the solder, the electric heater input is turned off, the outer heat insulating material 11 is removed, and the hollow steel shaft 8 is cooled from the outside by blowing cold air, etc., and the filled solder 3a is cooled.
Since it solidifies easily, the filling operation is completed by removing the vacuum device 6 afterwards.

As described above, according to this embodiment, the following effects can be achieved.

(1) When embedding a heat pipe in a shaft using a filler such as solder, a uniform filling layer can be easily obtained using the method of this embodiment, and the work is greatly simplified (vacuum is not required). - Can be left unattended during heating, and can be automated including cooling).

(2) Oxidation of solders is prevented and oxides are not entrained in the filled layer.

Furthermore, the same apparatus can also be used to use a curable resin such as a highly thermally conductive epoxy resin instead of solder as the filler. By appropriately raising the temperature using an electric heater, the fluidity of the resin is temporarily increased, making it easier to degas after filling.

By maintaining a predetermined temperature, effects such as accelerating the curing of the resin can be obtained.

The weight was chosen to be heavy enough to overcome the buoyancy caused by the filler and the frictional force caused by viscosity.

[Effect of the invention 1 As described above, the present invention places the closed end of the hole on the lower side, fills the bottom of the hole with a filler, inserts the heat pipe into the hole, and then inserts the filler into the open end of the hole and one end of the heat pipe. A vacuum suction device that has a weight of a predetermined weight that is in contact and can be moved freely in the axial direction, and that can be removed later, is installed via a vacuum seal, and after installation, the vacuum inside the hole is filled while bowing for a predetermined period of time. Since the agent is heated and solidified, the weight pushes the heat pipe into the bottom of the hole while heating the filler while vacuuming, and the filler fills the gap between the heat pipe and the hole. To obtain a method for embedding and fixing a heat pipe, which eliminates the drawbacks of the conventional technology by removing air bubbles and solidifying the heat pipe, and which makes it possible to easily and reliably fill and fix a heat pipe into a hole. I can do it.

[Brief explanation of drawings]

Figures 1 (al) and (b) show the embedding of a heat pipe into a hollow steel shaft according to an embodiment of the embedding/fixing method of the present invention, and (a) shows the initial state after the vacuum evacuation device is set. (b) is a vertical side view showing the state after filling is completed; FIG. 2 is a vertical side view showing embedding of the heat pipe in the heat transfer body by the conventional method of embedding and fixing the heat pipe. 2: Hole, 3a: Solder (filler), 4: Heat pipe, 5: Weight, 6: Vacuum device, : Vacuum seal, : Hollow steel shaft (heat transfer body) Number 2: +L True cloud meter Xia S: Severe eyes

Claims (1)

[Claims] 1. A heat method in which a heat pipe is embedded and fixed in a heat transfer body having a hole whose inner diameter is larger than the outer diameter of the heat pipe and whose one end is closed, using a fluid and solidifiable filler. In the method for embedding and fixing a pipe, the closed end of the hole is placed on the lower side, the filler is put in the bottom of the hole, and after the heat pipe is inserted into the hole, the heat pipe is placed on the open end side of the hole. A vacuum evacuation device that abuts one end and has a weight of a predetermined weight that is movable in the axial direction and is removed later is attached via a vacuum seal, and after attachment, the vacuum is drawn in the hole for a predetermined period of time. A method for embedding and fixing a heat pipe, characterized in that the filler is heated and then solidified.