JPH0763487A - Plate type heat pipe - Google Patents

Abstract

PURPOSE:To increase maximum number of turns of a plate type heat pipes to be contained by forming a zigzag long net groove on an adhering surface of a unit thin plate of a metal thin plate laminated structure, and sealing operating fluid in a boundary of laminated layers. CONSTITUTION:A plate type heat pipe is a welded laminate of a unit thin plate 1 and a flat thin plate 3 made of metal having excellent thermal conductivity. A series of long zigzag fine grooves 2 are previously formed on a welding surface of the plate 1 before laminating. The groove 2 may be formed by means for cutting, electric discharge processing, press molding, etc. The grooves 2 are formed as an enclosed zigzag small-diameter tunnel 4 by laminating, a predetermined quantity of predetermined operating fluid is sealed in the tunnel 4 to form a zigzag small-diameter tunnel heat pipe. Thus, the number of the pipes of several times as many as that of conventional plate can be contained in the same sectional area.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a plate heat pipe, and more particularly to a structure of a thin and lightweight plate heat pipe in which a layer of a meandering thin tunnel heat pipe is formed in a plate.

[0002]

2. Description of the Related Art In a conventional plate heat pipe, a metal flat plate 3-2 having a concave surface portion and a metal flat plate 3-1 are hermetically laminated and bonded as illustrated in a schematic sectional view 10 and a schematic plan view 11. In general, the concave portion is formed as a sealed plate-shaped container 6 in which a predetermined amount of hydraulic fluid is enclosed to form a plate-shaped heat visor. Reference numeral 7 is a supporting pillar for reinforcement. In practical use, various wicks are often formed on the inner wall surface of the plate-shaped container 6 to give a capillary action.

The conventional plate-type heat pipe constructed as described above has the problems that it cannot be used in the top heat mode and the performance in the horizontal heat mode is deteriorated, like the ordinary heat pipe. Further, the fact that the strength of the hydraulic fluid applied to the flat plate surface against the internal pressure is small has been a serious problem. That is, when the working temperature range of pure water is 80 ° C or less, the saturated vapor pressure of the working solution is small, so it is not a big problem. On the other hand, there is a risk that the plate plane may be deformed due to an increase in saturated vapor pressure. In order to prevent this, it is necessary to make the plate sufficiently thick, which causes problems such as an increase in heat resistance and an increase in weight. If the ambient temperature drops below zero, it is necessary to use a low temperature hydraulic fluid, and the low temperature hydraulic fluid generally has a saturated vapor pressure several times or a dozen times that of pure water. In order to increase the pressure resistance of the plate heat pipe, it is necessary to significantly increase the thickness of the plate, and the increase in weight due to this has been a serious problem in practical use.

In order to solve these various problems, a plate-type heat pipe in which a meandering thin pipe heat pipe is sandwiched and incorporated in a plate has been put into practical use. 12
Is a schematic sectional view showing the structure of an example thereof, and FIG. 13 is a schematic plan view thereof. In the figure, 8 is a loop type or non-loop type meandering thin tube heat pipe, which is a metal flat plate 3-3,
It is sandwiched by 3-4 and is hermetically adhered to the inner surface thereof by the brazing filler material 10. Reference numeral 9 is a spacer for preventing the brazing material from flowing out during brazing. Since this heat pipe container is a thin tube with an outer diameter of 2 mm and an inner diameter of 1.2 mm, it has extremely high pressure resistance, and even in the case of a pure copper thin tube container or an aluminum thin tube container, it is 100 kg / c.
It had a strength capable of easily withstanding an internal pressure of m ² or more, and could sufficiently reduce the thickness of the plate.

The meandering thin tube heat pipe applied to the present invention has the following various structures. That is, JP-A-63
There are three types: −318949 (loop type thin tube heat pipe), Japanese Patent Application No. 2-319461 (loop type thin tube heat pipe), and Japanese Patent Application No. 3-61385 (micro heat pipe). In JP-A-63-318493, both ends of a meandering thin tube heat pipe are rotatably connected to each other to form an endless loop, and check valves are provided at a plurality of predetermined positions in the loop, so that the hydraulic fluid is It excels in top heat mode characteristics because it is a form in which the amount of heat is conveyed by circulating it in a predetermined direction. In Japanese Patent Application No. 2-319461, the check valve in the loop is omitted, and the amount of heat is conveyed by both the axial vibration of the hydraulic fluid and the circulation of the hydraulic fluid in an unspecified direction. Suitable for transportation. Japanese Patent Application 3-61
385 is a non-loop type, the container does not form a loop, and the amount of heat is carried only by the axial vibration of the hydraulic fluid, which is suitable for thinning and downsizing, and has excellent reliability.

All of these three types of meandering thin tube heat pipes have the common advantage that they can be actively operated in any holding posture. Therefore, the plate type heat pipe incorporating these meandering thin tube heat pipes has solved all the problems of the conventional plate type heat pipes.

[0007]

The plate type heat pipe having the meandering thin tube heat pipe as described above solves all the problems in the past, but it is still not possible to completely satisfy the demands of the industry. There was a problem like that.

(A) The performance of the meandering thin tube heat pipe is improved as the number of turns of the meandering in the same plane of the plate is increased. Especially, the performance in the top heat mode is the performance in the bottom heat mode. It is experimentally known that 30 turns or more are required in a 100 mm width experimentally in order to operate well without much difference. However, the radius of curvature of the thin tube container is, for example, about 1.5 times the outer diameter of the tube at the center line as the minimum limit in the case of a pure copper thin tube, and it is also known that if the radius of curvature is made smaller than this, it becomes in a buckling state. Eg 1
In order to hold a meandering thin tube having an outer diameter of 3 mm in a 00 mm width, it is necessary to connect the tubes at a pitch of 9 mm, and the maximum number of holding tubes is about 11 turns. That is, in order to exert good performance irrespective of the holding posture, it is necessary to sandwich and embed a three-layer meandering thin tube container. This means that the minimum limit of the plate thickness is about 13 mm, which means that the performance must be sacrificed to construct a plate having a smaller thickness.

(B) The demand for miniaturization and weight saving of equipment in the industry has never stopped, and the weight and the weight of the built-in meandering thin tube heat pipe cannot be ignored, and for further size and weight reduction. Measures are becoming necessary.

(C) In order to further improve the performance, it is desired to reduce the contact thermal resistance between the meandering thin tube heat pipe and the sandwiching metal flat plate. The contact between the metal flat plate and the meandering thin tube container is a line contact or a broken line contact, and the filling adhesion with the brazing material for reducing the contact thermal resistance increases the weight of the plate heat pipe and lowers the thermal response performance. I am busy.

(D) The thin tube container is bent for a large number of turns with a small radius of curvature, and the large number of turns and a large number of layers are accurately and precisely aligned and sandwiched between the metal flat plates, and the brazing work is not easy work. There is no choice but to rely on difficult manual work at high temperatures. In addition, mass production is difficult and cost inevitably increases. Due to these factors, although the plate heat pipe meets the needs of the industry, it is delayed in practical use except for special purposes. Cost reduction by mechanization and automation of plate type heat pipe manufacturing work is becoming an urgent issue. The present invention solves each of the problems (a), (b), (c), and (d).

[0012]

The basic concept of means for solving the problems will be described with reference to the schematic sectional view of FIG. A series of meandering lengths that meander at a predetermined depth, a predetermined width, and a predetermined pitch on a predetermined bonding surface of a predetermined unit thin plate 1 of a plate that is a laminated structure of metal thin plates 1 and 3 having good thermal conductivity. The narrow groove 2 is formed, and the meandering groove is either an endless loop type in which both ends thereof are connected or a non-loop type in which both ends are not connected,
A plurality of the unit thin plates are stacked on top of each other, or a unit thin plate and a flat thin plate on which a narrow groove is not formed are stacked on top of each other. A predetermined number of layers having a long and narrow closed tunnel 4 are formed.

A predetermined amount of a predetermined heat pipe hydraulic fluid is enclosed in the closed tunnel to form a loop type meandering thin tunnel heat pipe having the same internal structure as the loop type meandering thin tube heat pipe or the non-loop type meandering thin tube heat pipe. It is configured as a non-loop type meandering small-diameter tunnel heat pipe, and the circular equivalent diameter of this small-diameter tunnel is that the hydraulic fluid enclosed in the tunnel always closes the inside of the tunnel due to its surface tension, and it can be used in any holding posture. It is configured to have a diameter that is sufficiently thin so as to circulate or vibrate in the axial direction of the tunnel while maintaining this closed state.

[0014]

The plate type heat pipe constructed as described above exhibits the following actions. (B) The meandering small-diameter tunnel heat pipe that can be built in can reduce the radius of curvature of the turn portion to the utmost limit. In other words, it becomes possible to connect at a high density with a pitch that is only the width of the narrow groove plus about 1 mm of the width of the groove, and a tunnel heat pipe with many turns can be built in. Therefore, it is possible to construct a plate-type heat pipe with high performance and thin thickness. As an example, outside diameter 3mm inside diameter 2
When a tunnel heat pipe is built in instead of the mm meandering thin tube heat pipe, a tunnel with a diameter of 2 mm can be built in with a pitch of 3 mm, and a plate type with a thickness of 5 mm in which 33 pieces are arranged in a 100 mm width. It becomes possible to configure a heat pipe, and the number of built-in units is three times,
The thickness is greatly improved to 1/2.

(B) Incorporating the meandering small-diameter tunnel heat pipe reduces the weight and wall thickness of the thin tube container as compared with the case where the meandering thin tube heat pipe is incorporated by sandwiching and bonding, and comparing with the sandwiching and bonding plate. Since the lamination plate does not require so much strength, it can be made thin, and the weight of the adhesive and the filler for sandwiching and bonding will be zero. It will be possible.

(C) When a meandering thin tube heat pipe is built in by sandwiching and adhering, a large contact heat resistance is generated, whereas the built-in meandering small diameter tunnel heat pipe has a zero contact heat resistance and therefore has a performance. Greatly improved.

(D) The meandering small-diameter tunnel heat pipe is formed by only two steps, that is, the meandering narrow groove forming step and the laminating step by welding. The meandering fine grooves can be formed by automatic cutting, batch forming by electric discharge machining, batch forming by high pressure press, etc. All of them are easy to automate and do not require machining time, Precision processing is easy. In addition, the stacking process also uses a large-scale heat treatment furnace to perform batch mass stacking,
It can be easily carried out by stacking by semi-automatic heat treatment by a continuous heat treatment furnace. Both processes are easy processes for mass production at low cost. Therefore, in mass production, a significant cost reduction can be achieved.

[0018]

【Example】

First Embodiment FIGS. 1 to 6 are explanatory views of various embodiments of a plate heat pipe configured by carrying out a first embodiment of the present invention. Both are welded laminates of a unit thin plate 1 and a flat thin plate 3 made of a metal having good thermal conductivity. A series of long meandering fine grooves 2 are formed in advance on the welding surface of the unit thin plate 1 prior to lamination. The fine groove 2 may be formed by any means such as cutting, electric discharge machining, and press molding. The long meandering narrow groove 2 is formed as a closed meandering thin diameter tunnel 4 by stacking, and a predetermined amount of a predetermined working liquid is enclosed in the closed tunnel 4 to form a meandering small diameter tunnel heat pipe 4-1. .

FIG. 1 shows an example in which a unit thin plate 1 in which a long meandering narrow groove 2 is formed and a simple flat thin plate 3 in which no narrow groove is formed are laminated. FIG. 2 shows two unit thin plates 1-1 and 1-2 each having a long meandering narrow groove 2 having a semicircular cross section.
In this example, the thin groove surfaces of and are laminated so as to face each other. In this case, the meandering small-diameter tunnel 4 has a circular cross-sectional shape, which is advantageous in that unnecessary resistance is less likely to occur when the working fluid circulates and vibrates. In FIG. 3, two unit thin plates 1-1 and 1-2 and a flat thin plate 3 constitute a two-layer meandering small-diameter tunnel 4. Fig. 4 also shows two unit thin plates 1-
Two layers of the meandering small-diameter tunnel 4 are constituted by three sheets 1 and 1-2 and the flat thin plate 3, and the two-layer meandering small-diameter tunnel 4 is sandwiched around the flat thin plate 3 and the target shape is the thin meandering tunnel 4. It is characterized in that it is arranged and formed in. 5 and 6 are schematic plan views showing the planar shape of the meandering small-diameter tunnel heat pipe. The meandering thin tunnel heat pipe shown by removing a part of the flat thin plate 3 is a loop type meandering thin tunnel heat pipe 4-1 in FIG. 5, and is a non-loop type in FIG. It is a meandering thin tunnel heat pipe 4-2.

Second Embodiment FIG. 7 is an explanatory view of the second embodiment of the present invention, in which the unit thin plate 1 is used.
3 shows a high-density aligned state of meandering fine grooves on the plane of FIG. A group of thin grooves 2-1 having a predetermined depth and a predetermined width are formed in parallel and in parallel on the bonding surface of the unit thin plate 1, and the turn portion in the group of these thin grooves 2-1 is formed. The adjacent narrow grooves that form a pair are formed in pairs, and the pair of narrow grooves 2-1 are formed.
Is always formed up to the same position on the unit thin plate surface, and a groove crest 2-2 formed between a pair of narrow grooves 2-1.
Are notched by a predetermined length at the end portions of the pair of narrow grooves, and the groove mountain notch portion 2-3 allows the end portions of the pair of narrow grooves to freely flow with each other. The thin groove turn portion 2-4 is formed, and thus the entire thin groove group is formed as a long meandering thin groove 2 having a large number of turn portions.

Since the group of the fine grooves 2-1 formed in this manner can be arranged at intervals of the width of the groove crests 2-2, they can be arranged in an extremely high density state. , It becomes possible to incorporate a meandering small-diameter tunnel with a number of turns that is several times that of the conventional meandering thin-tube container in the plate-shaped heat pipe.

Third Embodiment FIG. 8 is a sectional explanatory view of a third embodiment of the present invention. In this embodiment, a plurality of layers of meandering thin tunnel heat pipes 4-1 and 4 are used.
-2, the meandering small diameter tunnel heat pipes 4-1 and 4-2 of the adjacent layers are connected to each other by the connection pores 5 penetrating the layers in the plate-shaped heat pipe configured by laminating layers of -2. It is characterized in that it is constructed as a series of long loop type meandering small diameter tunnel heat pipes or non-loop type meandering small diameter tunnel heat pipes.

In FIG. 8, a plurality of layers of meandering small-diameter tunnel heat pipes 4-1 and 4-2 are formed on the bonding surfaces of unit thin plates 1-1 and 1-2, which are units of lamination, respectively. The adhesive surfaces are laminated on both sides of the flat thin plate 3 with the flat thin plate 3 sandwiched therebetween, and a predetermined amount of a predetermined working fluid is enclosed in the meandering small-diameter tunnel formed thereby. Being meandering thin tunnel heat pipes 4-1 and 4-
It is configured as 2. These small-diameter tunnel heat pipes are connected at their respective ends by connecting pores 5 penetrating the flat thin plate 3 forming a partition wall between them,
It is characterized in that both hydraulic fluids are connected so that they can freely flow, and are configured as a series of long and narrow meandering tunnel heat pipes as a whole.

Like the meandering thin tube heat pipe, the meandering thin tunnel heat pipe has a higher performance as the number of meandering turns is increased in a series of meandering heat pipes.
When the number of turns exceeds a certain number of turns, the same high performance is exhibited regardless of the applied posture mode in any applied posture. As in this example, the connecting pores 5
Due to the meandering thin tunnel heat pipe 4-1 in the adjacent layer,
When 4-2 is connected to be configured as a series of heat pipes, the performance of the plate heat pipe is further improved as compared with the case where each is individually configured. This also has the advantage that the plate-type heat pipe has the same performance on the front and back sides and eliminates the temperature difference between the front and back sides.

This embodiment is not limited to the laminated structure in which the flat thin plate 3 is interposed as shown in FIG. The plate-shaped heat pipe as illustrated in FIG. 2 may be a structure in which a plurality of layers are stacked as a unit layer, or a structure in which a plurality of layers of only the unit thin plate 1 are stacked. By providing the connecting pores 5 in the portions corresponding to the partition walls between the layers, the multilayer structure in which the meandering small-diameter tunnel heat pipes of the respective layers are interconnected to form a series of meandering small-diameter tunnel heat pipes Can be applied to.

Fourth Embodiment FIG. 9 is a plan view showing a fourth embodiment of the present invention. The present embodiment is characterized in that in a plate-type heat pipe having a plurality of layers of a serpentine small-diameter tunnel structure, the serpentine small-diameter tunnel groups of adjacent layers are arranged so that their ring directions are orthogonal to each other. In FIG. 9, reference numeral 3 indicates a flat thin plate 3 in a plate heat pipe having a laminated structure of a plurality of unit thin plates 1 and a flat thin plate 3. Reference numerals 4-1 and 4-2 respectively denote a meandering small-diameter tunnel heat pipe which is formed in a predetermined adjacent layer among the plurality of layers. In the figures, the non-loop type is shown, but this may be the loop type. As is apparent from the figure, the straight tube portions of both meandering small-diameter tunnel heat pipes are arranged so as to be orthogonal to each other.

Similar to the meandering thin tube heat pipe, the meandering thin tunnel heat pipe is a heat transporting method in which the heat quantity is transported by circulating the working fluid or axial vibration, and the heat quantity is transported only in the length direction of the tunnel. Be seen. Therefore, in the layer containing the meandering small-diameter tunnel heat pipe, the heat carrying capacity in the direction orthogonal to the length direction of the tunnels arranged in parallel and parallel is extremely poor, and a large temperature gradient is generated in this direction. Occurs.

When the straight pipe groups of adjacent layers are arranged so as to be orthogonal to each other as in the present embodiment, the directions of the heat transporting capacities of the respective layers complement each other and the plate type heat pipe is used. Is improved to provide uniform heat transfer capacity in all directions. As a result of the experiment, it was proved that in such a plate heat pipe, the surface of the plate was heated to the same temperature regardless of the amount of heat applied to any position of the plate, and the temperature unevenness was extremely small. As shown in FIG. 9, when the meandering small-diameter tunnel heat pipes between adjacent layers are connected to each other by the connecting pores 5 to constitute a series of meandering small-diameter tunnel heat pipes, the surface temperature equalizing characteristic of the plate-type heat pipe is As the temperature is further improved, the temperature difference between the layers is made uniform.

[0029]

According to the plate type heat pipe as described above, the tunnel structure is formed in the thin plate of the plate, and the thin tube container is abolished. Since it is possible to build in, it is possible to reduce the thickness of the plate to one half or less of the conventional thickness, the thermal resistance value is also reduced to a few times, and it is possible to achieve large size and weight reduction and high performance. become. The application range of the plate heat pipe thus improved is greatly expanded. As an application example, the point that the whole plate is cooled by cooling a part is as follows: (a) A cold plate of a large computer, a cold plate that is inserted between printed circuit board groups to cool them, and a large number of heating elements collectively cooled There are cold plates, heat transport ribbons that take out heat from the narrow gaps between mounted parts and cool it,
As an application example of the point where the temperature of the entire plate rises due to some heating, (b) there is a heat diffusion plate for cooling the heating element, which is powerful and compact and difficult to dissipate heat. There is also a heat treatment plate, and by applying elastic properties to the material of the plate, it is possible to apply (d) as a detachable thermal connection ribbon, (e) as a detachable cold plate, etc. Another advantage of the present invention is that it is expected to achieve epoch-making cost reduction as compared with a plate-type heat pipe with a meandering thin tube heat pipe. This is because the process can be constituted by only two steps, and any of the steps is a step in which mass production is easy and automation is easy.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of the configuration of a first embodiment of a plate heat pipe of the present invention.

FIG. 2 is a sectional view showing a second example of the configuration of the first embodiment of the plate heat pipe of the present invention.

FIG. 3 is a sectional view showing a third example of the configuration of the first embodiment of the plate heat pipe of the present invention.

FIG. 4 is a sectional view showing a fourth example of the configuration of the first embodiment of the plate heat pipe of the present invention.

FIG. 5 is an explanatory view showing an example of a planar internal structure of the first embodiment of the plate heat pipe of the present invention.

FIG. 6 is an explanatory view showing another example of the planar internal structure of the first embodiment of the plate heat pipe of the present invention.

FIG. 7 is an explanatory view showing a second embodiment of the plate heat pipe of the present invention.

FIG. 8 is an explanatory view showing a third embodiment of the plate heat pipe of the present invention.

FIG. 9 is an explanatory view showing a fourth embodiment of the plate heat pipe of the present invention.

FIG. 10 is an explanatory sectional view showing an example of the structure of a plate-type heat pipe having a conventional structure.

11 is an explanatory plan view showing a planar structure of the plate heat pipe of FIG.

FIG. 12 is a cross-sectional explanatory view showing another example of the structure of the plate-type heat pipe having the conventional structure.

13 is an explanatory plan view showing a planar structure of the plate heat pipe of FIG.

[Explanation of symbols]

 1 unit thin plate 2 long meandering narrow groove 2-1 narrow groove 2-2 groove mountain 2-3 groove groove removing part 2-4 turn part 3 flat thin plate 3-1 metal flat plate 3-2 metal flat plate 3-3 metal flat plate 3-4 Metal flat plate 4 Meandering small-diameter tunnel 4-1 Loop type meandering small-diameter tunnel heat pipe 4-2 Non-loop type meandering small-diameter tunnel heat pipe 5 Connecting pores 6 Plate type container 7 Support column 8 Meandering thin tube heat pipe 9 Spacer 10 Brazing filler

Claims (4)

[Claims] 1. A plate type heat pipe in which a heat pipe is embedded in a laminated structure of unit thin plates made of a metal material having good thermal conductivity, and a predetermined unit thin plate has a predetermined bonding surface. Is formed with a series of meandering long narrow grooves that meander at a predetermined depth, a predetermined width, and a predetermined pitch.The meandering narrow grooves form an endless loop shape in which both ends are connected or both ends are formed. Either it is a non-loop type that is not connected, and whether multiple unit thin plates are stacked on top of each other, or unit thin plates and flat thin plates on which no thin grooves are formed are stacked on top of each other. By any of the above, a predetermined number of layers having a long and narrow closed tunnel meandering on the stacking boundary surface in the plate is formed, and a predetermined amount of a predetermined heat pipe hydraulic fluid is enclosed in the closed tunnel, Loop type meandering capillary tube heat pie Or a non-loop type meandering thin tube heat pipe with the same internal structure as a loop type meandering small diameter tunnel heat pipe or a non-loop type meandering small diameter tunnel heat pipe, and the circular equivalent diameter of this small diameter tunnel is a tunnel. The hydraulic fluid enclosed in the inside always closes the inside of the tunnel due to its surface tension, and the diameter is sufficiently thin so that it circulates or vibrates in the axial direction of the tunnel while maintaining this closed state in any holding posture. A plate-type heat pipe characterized by this. 2. A group of thin grooves having a predetermined depth and a predetermined width are closely formed in parallel and in parallel on a bonding surface of a predetermined unit thin plate, and a turn portion is formed in the narrow groove group. Adjacent narrow grooves are formed in pairs, and the ends of the pair of narrow grooves are always formed to reach the same position on the unit thin plate surface.
The groove crests formed between the pair of narrow grooves are notched by a predetermined length at the ends of the pair of narrow grooves, whereby the ends of the pair of narrow grooves are mutually separated. 2. It can be freely flown into a groove and is formed as a turn portion of a narrow groove, and the whole thin groove group is formed as a long meandering pore having a large number of turn portions. Plate type heat pipe. 3. A plate type heat pipe constructed by laminating a plurality of layers of meandering thin tunnel heat pipe layers, wherein the meandering small diameter tunnel heat pipes of each layer are connected to each other by connecting pores penetrating the layers. 2. The plate heat pipe according to claim 1, wherein the plate heat pipe is configured as a series of long loop type meandering small diameter tunnel heat pipes or non-loop type meandering small diameter tunnel heat pipes. 4. A plate-type heat pipe having a plurality of layers of meandering small-diameter tunnel structures, wherein the meandering small-diameter tunnel groups of adjacent layers are arranged so that their axial directions are orthogonal to each other. The plate-type heat pipe according to item 1. G-shaped heat pipe.