JP3045491B2 - Heat pipe and this processing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-dissipating heat pipe used for information electronic equipment and the like, and a method for processing the same.

[0002]

2. Description of the Related Art Information electronic devices such as notebook PCs meet the demand for light weight and thinness, and with the integration of functions,
The heat generation density of electronic components such as U has become extremely high. In order to meet this demand, thin-plate heat pipes have been used for heat distribution of the heat-generating components.

In order to make a heat pipe thin,
It is necessary to reduce the steam passage of the working fluid to near the limit of the required heat flow rate, to control the accuracy of the internal area by inserting a core during processing, and to minimize the thickness of the container material.

[0004]

However, in order to withstand the mechanical pressure from the outside to the container and the internal pressure due to the gas-liquid two-phase change even if these operations are performed, the liquid generated due to the starting characteristics of the heat pipe is required. Since pools are generated partially in the axial direction of the heat pipe and cause an increase in thermal resistance, there is naturally a limit to the reduction in thickness, and conventionally the thickness of the material is 1.
Only about 5mm was realized.

In view of the above problems, the present invention has a thickness of 1 mm.
It is an object of the present invention to provide a heat pipe capable of obtaining a good effect and a processing means for the heat pipe, even if

[0006]

According to the present invention, in order to solve the above-mentioned problems, a core which is normally taken in and out for each processing is provided as an optimal structure for a wick to be incorporated into a heat pipe for circulating hydraulic fluid. In addition, it is possible to provide a heat pipe which is extremely thin, having a thickness of 1 mm or less, and which has excellent heat transport capability and heat resistance characteristics, by taking measures to leave each heat pipe.

That is, in the first aspect, a flat container and a heat pipe in which a rod, a plate, or a mesh is fixedly installed between the narrow walls of the container so as to have a space in at least both sides in the width direction inside the container. In claim 2, the amount of the working fluid is set at 2 times the volume of the container space.
Claim 1 is a first heat pipe enclosed by 5% or more. In Claim 3, the first pipe, the second pipe having a relatively small diameter and a shorter length than the first pipe, and A heat pipe in which at least one second pipe is inserted and fixed in a substantially central portion of one pipe, a working fluid is put in the first pipe, and the ends are sealed, and at least both widthwise side surfaces inside the container. Wherein the first and second pipes are configured as flat heat pipes so that the working liquid can freely move not only in the axial direction but also in the width direction of the second pipe. In the above, the second pipe is a heat pipe according to the third aspect using a pipe made of a mesh or a braided wire. In the fifth aspect, the container has a groove processing or a mesh inside the container. The heat pipe according to optimum claim 4, in claim 6, a first pipe, a short relatively small diameter and a length of, in comparison with the first pipe a second pipe,
Using a core rod, insert at least one second pipe at the approximate center of the first pipe and temporarily fix it, and fix the second pipe to the inner wall by flattening the first pipe with a press Then, after removing the core rod, a working fluid is put into the first pipe, the end is sealed, and then a flattening process is performed again. The pipe, the second pipe having a relatively small diameter compared to the first pipe, and a short length, at least one second pipe is inserted into a substantially central portion of the first pipe using a core rod. Temporarily fixed, fix the second pipe to the inner wall by pressing the first pipe into a flat plate with a press, and then pull out the core rod, the second pipe is flat except for at least the injection part Of a heat pipe with a working fluid in the first pipe Modulo.

[0008]

Embodiments of the present invention will be described below. FIG. 1 is an overall perspective view of the first embodiment, in which a dotted line disposed substantially at the center indicates a wick also serving as a core,
FIG. 2 is a cross-sectional view of the AA cross section as viewed in the direction of the arrow.
FIG. 3 is an axial sectional view of the heat pipe shown in FIG.
Shown in The first embodiment will be described with reference to FIGS. 1 to 3. The first pipe 10 is formed by flattening a cylindrical material having a hollow inside, and the axial ends thereof are respectively squeezed. There are a processing unit 11 and a press unit 14, and a container 12 is located between the two ends. The drawing portion 11 serves as a working fluid injection port, and forms a sealing portion 15 in the assembling process to seal the inside of the first pipe 15. As described above, the first pipe 10 is flat, has a groove 13 formed therein as shown in FIG. 2, and has a length less than the effective length of the container 12. The second pipe 20 has a shape in which the internal space is crushed, as shown in FIG. Here, the groove 13 is the first pipe 10
And the second pipe 20 forms a plate-and-bar-shaped wick. At this time, the first pipe
Both sides of the inner wall 10 and the outer wall space of the second pipe 20 mainly serve as a steam passage, and the inside of the second pipe 20 mainly serves as a hydraulic fluid return path.

More specifically, the first pipe 10
Is about 0.18 mm thick, about 0.12 mm high grooved outer diameter of about 3 mm to about 15 mm Oxygen-free copper or phosphorous deoxidized copper pipe material was cut to a length of about 180 mm, for example Thereafter, one end is drawn to a small diameter to inject the working fluid. The second pipe 20 is made of oxygen-free copper or phosphorus deoxidized copper having a thickness of about 0.12 mm to 0.25 mm and an outer diameter of about 1.2 mm to 3 mm, and has an effective length of the container 12 as the first pipe 10. It has been cut to a length less than that and the internal space has been crushed.

Next, a method of processing a heat pipe according to the present invention will be described with reference to FIGS. Fig. 4 shows the first pipe
FIG. 6 shows a drawing in which one end of 10 is drawn, and FIG. 6 shows a drawing in which the first pipe 10 of FIG. 4 is temporarily pressed and the second pipe 20 is fixed inside the first pipe 10. 5 shows A- of FIG.
FIG. 7 is a cross-sectional view of the section A as viewed in the direction of the arrow, and FIG. 7 is a view showing a state where the first pipe 10 shown in FIG. 6 is further pressed.

In FIG. 4, one end of the first pipe 10 is drawn to a small diameter in order to inject the working fluid to form a drawn portion 11 and a working fluid inlet 16. . Thereafter, the other end of the first pipe 10 is inserted through the core rod 30 made of a piano wire or phosphor bronze into the container 12 after the drawing process, and set in a press jig.
As shown in FIG.
Is temporarily fixed, and in this state, the outer shape of the second pipe 20 is flat-pressed with dimensional control to be fixed to the inner wall of the first pipe 10, and the shape shown in FIG. 6 having the cross-sectional state shown in FIG. After that, the core rod 30 is pulled out.

Further, after the pressing part 14 is pressed, it is sealed by welding or brazing, and the drawing part 11
12Depressurize the inside, inject a predetermined amount of working fluid such as pure water,
By pressing the vicinity of the root of the drawn portion 11 and cutting and welding unnecessary portions, the heat pipe is completed for the time being and then flattened to the desired final shape.

In the above-mentioned other processing method, the core rod 30 is pulled out, set on a different pressing jig from the above, and re-pressed while leaving the vicinity of the drawn portion 11, and FIG. After having the shape shown in FIG. 7 having the cross-sectional structure shown in FIG. 7, sealing of the press section 14 and injection of the working fluid are performed in the same manner as described above to form a heat pipe, and finally, the drawing section 11 is press-shaped. By doing so, all the steps of the heat pipe processing are completed.

The reason why the processing for forming the final shape is performed separately from the pressing of the whole or the drawing section 11 is that the step of putting the working fluid into the heat pipe is performed in the degassed container 12. Degassed purified water is measured and then injected.However, because the flat space of the thin heat pipe and the cross-sectional area are small, the working fluid injected into the container 12 becomes difficult to enter, and the working fluid amount is reduced from the control limit. A countermeasure against the problem of easy detachment and a countermeasure against the material softening due to the welding heat of the sealing portion 16 are simultaneously solved by thinning the injection portion only after the injection.

That is, the inside of the container 12 is depressurized from the injection port 15 and working fluid (not shown) is injected.
When the volume of the internal space near the drawing portion 11 is relatively large, not only a sufficient pressure reduction inside the container 12 can be obtained, but also the injection speed of the working fluid is not hindered, and the variation of the injection amount can be controlled to be extremely small. Will be. Also, after the working fluid is injected, the inlet 15 is sealed and heated by the welding heat to induce the softening of the material from the inlet 15 to the drawing part 11, but the drawing processing part 11 is flattened in the final step to process the material of the container 12. Hardening is promoted, and the softening of the material due to welding heat returns to almost the hardness before welding.

Next, the operation of the heat pipe having the above configuration will be described. Inside the container 12 having the groove wick on the inner wall, a plate-shaped wick made of the second pipe 20 whose inside is crushed is formed, and when the heat pipe is operated, it comes into contact with the inner wall of the container 12 on the outer periphery of the plate-shaped wick. The part that works acts as a valid wick. Further, since the loop-shaped heat pipe is formed over the entire circumference in the container, the influence of the capillary pressure limit and the scattering limit is small.

Further, by having the above-mentioned loop-shaped heat pipe structure, when the steam passage must be set to be extremely small, the amount of the working fluid is reduced to two times the container space volume.
By making it relatively large, such as 5% or more, generation of a pressure-fluctuation oscillating flow of vapor bubbles due to nucleate boiling of the working fluid is promoted, and heat transfer can be performed effectively.

FIG. 3 is a view for modeling and explaining the operation when the flat thickness of the heat pipe of the above embodiment is set to be small. The inner wall of the container 12 has grooves, meshes, etc. There is no wick. This figure 3
In, the space shown inside the container 12 is a gas phase, the dotted line part is a liquid phase, and by heating the heat receiving part, the working fluid becomes nucleate boiling and becomes a vapor bubble, and at the same time a pressure vibration wave is generated,
The heat transport is performed by a phenomenon in which all the vapor bubbles that have taken the latent heat expand and contract and move to the radiator side.

As described above, since the heat transport by the slag flow is performed, it is governed by the surface tension of the working fluid. However, there is no capillary pressure or scattering limit due to the vapor flow pressure in the ordinary heat pipe, and the container is narrow. It is possible to make the wall interval as thin as possible.

In FIG. 3, which is the model diagram, the role when a wick such as a group or a mesh is provided is unclear, but the wick is installed when it is not necessary to narrow the container narrow wall interval to the limit. In addition, it is mainly responsible for the auxiliary role of the pumping action of the hydraulic fluid reflux in the axial direction and the heat transfer in the cross-sectional direction.

In the above embodiment, a groove wick material is used inside the first pipe 10. However, it is needless to say that a material having a small cross-sectional area or a material having a relatively short length can be used. The groove wick is not always necessary, and in some cases, it is better not to have a groove wick in order to reduce the thickness. In addition, it is sometimes convenient to use the pipe wick material after deforming it into an elliptical shape or an eyeglass shape in advance, and the pipe wick material is not necessarily limited to the pipe cross section. A wire or the like can be appropriately inserted. Further, the respective pipes and working fluid are not limited to copper or pure water, and similar thin heat pipes can be obtained by using other well-known materials. The number of pipe wicks used as the second pipe 20 is not limited to one, and a plurality of pipe wicks may be prepared.

The work hardening method in the first embodiment can be similarly applied to the press section 14 if necessary. Also,
In the first embodiment described above, the wick made of the groove 13 is provided on the inner wall of the container 12, but this may be installed with a mesh or the like, or as shown in FIG. It may not have a wick. FIG. 8 shows a second embodiment, which is the same as or equivalent to the first embodiment except that it does not have a groove 13 inside the container 12, and a description thereof will be omitted. Such a heat pipe of the second embodiment is effective for thinning.

The first and second rods are also cores and are used as partition plates for forming a loop-shaped heat pipe.
In the embodiment, the second pipe 20 is used. However, it is needless to say that the pipe such as a mesh or a braided wire as shown in FIG. A similar effect can be obtained by using a partition bar 28 in a shape of a bar, or by using a bar or plate instead of a pipe as the partition bar 28 as shown in FIG. The third and fourth embodiments are the same as or equivalent to the first embodiment except that another partition plate bar 28 is provided instead of the second pipe 20, and the description is omitted. I do. In the third and third embodiments, the groove 13 may be eliminated as shown in the second embodiment.

In some cases, it is more convenient to use the second pipe 20 after deforming it into an elliptical shape or an eyeglass shape.
Needless to say, the shape is not necessarily limited to the pipe cross section, and a wire or the like can be appropriately inserted into the second pipe 20 as a wick auxiliary material. In addition, each of the above embodiments
In, the second pipe 20 is an effective
Although the length is less than the length, the second pie
The length of the pipe 20 is such that the second pipe 20 is relatively coarse
Wicks or narrow wicks,
Pipe 20 and the container 12 have the same length,
Only at least in the width direction on both sides inside the container 12
It is good also as a structure which has space.

Further, each pipe and working fluid is not limited to copper or pure water, and a similar thin heat pipe can be obtained by using a known material.

[0026]

As described above in detail, according to the first to fourth embodiments, the first pipe having the outer shape selected by the required container width and the wick material selected by the required container thickness are used. By optimally combining one or more rods, plates, or meshes, or the second pipe, the core to be taken in and out for each processing required for precision control, which is indispensable especially for thin sheet processing during flat processing In addition to eliminating the need for heat shaping to correct dent deformation after completion of the heat pipe, it is possible to obtain a loop-shaped heat pipe that exhibits excellent characteristics of hydraulic fluid recirculation, enabling the maximum possible reduction in thickness. A heat pipe and a heat pipe processing method can be obtained.

Further, since the heat pipe itself is not easily deformed, variations in individual characteristics are small, and the heat pipe has many excellent characteristics, such as being capable of being used after bending after completion of the heat pipe.

[Brief description of the drawings]

FIG. 1 shows a perspective view of a heat pipe of the present invention.

FIG. 2 is a cross-sectional view of the AA cross section of FIG.

3 shows an axial sectional view of FIG. 1;

FIG. 4 shows a perspective view of the heat sink of the present invention during manufacture.

FIG. 5 is a cross-sectional view of the AA cross section of FIG.

FIG. 6 shows a perspective view after the heat pipe of the present invention is temporarily pressed.

FIG. 7 shows a perspective view of the heat pipe container of the present invention after pressing.

FIG. 8 is a sectional view of a heat pipe according to a second embodiment of the present invention.

FIG. 9 is a sectional view of a heat pipe according to a third embodiment of the present invention.

FIG. 10 is a sectional view of a heat pipe according to a fourth embodiment of the present invention.

[Explanation of symbols]

 In the drawings, the same reference numerals indicate the same or corresponding parts. DESCRIPTION OF SYMBOLS 10 First pipe 11 Drawing part 12 Container 13 Groove (groove wick) 14 Press part 15 Sealing part 16 Inlet 20 Second pipe (Pipe wick) 28 Partition plate rod 30 Core rod

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-8-303972 (JP, A) JP-A-4-43290 (JP, A) JP-A-48-1001639 (JP, A) JP-A-55-1983 25781 (JP, A) JP-A-8-327261 (JP, A) JP-A-8-303971 (JP, A) JP-A-11-173777 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F28D 15/02 102 F28D 15/02 101 F28D 15/02 106

Claims (7)

(57) [Claims] 1. A flat container and a small container inside the container.
So that there is space in both sides in the width direction ,
A heat pipe with a rod, plate or mesh fixed between the narrow walls of the container. 2. The heat pipe according to claim 1, wherein the amount of the working fluid is enclosed by 25% or more of the volume in the container space. 3. A first pipe, a second pipe having a relatively small diameter and a shorter length than the first pipe, and at least one second pipe substantially at the center of the first pipe. This is a heat pipe which is inserted and fixed, the working fluid is put in the first pipe and the end is sealed, and at least both widthwise side surfaces inside the container are mainly steam passages, and the second pipe is of course in the axial direction. A heat pipe in which the first and second pipes are configured so that the working liquid can move freely also in the width direction. " 4. The heat pipe according to claim 3, wherein the second pipe is a pipe made of a mesh or a braided wire. 5. The heat pipe according to claim 1 , wherein a groove or mesh is provided inside the container. 6. A first pipe, a second pipe having a relatively small diameter and a short length as compared with the first pipe, and a second pipe substantially at the center of the first pipe using a core rod. At least one is inserted and temporarily fixed, the second pipe is fixed to the inner wall by flattening the first pipe with a press, and then the core rod is removed, and then the first pipe is actuated A method of processing a heat pipe in which a flattening process is performed again after the end is sealed by filling a liquid. 7. A first pipe, a second pipe having a relatively small diameter and a short length as compared with the first pipe, and a second pipe substantially at the center of the first pipe using a core rod. And temporarily fix it by inserting at least one, fix the second pipe to the inner wall by pressing the first pipe into a flat plate with a press, and then pull out the core rod, leaving at least the injection part A method of processing a heat pipe in which a second pipe is flattened and a working fluid is poured into the first pipe to seal an end.