JP3709868B2 - Cooling system for electronic equipment - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a cooling system used for an electronic device.
[0002]
[Prior art]
When the amount of heat generated by elements such as CPUs mounted on electronic devices such as workstations and personal computers becomes enormous, forced air cooling using a fan to dissipate heat (JP-A-2-83958) There is a proposed method in which an existing heat pipe is stretched around and fixed to the casing, and heat is radiated from the entire large casing. In addition, a structure in which a heat pipe is integrated in a metal casing has been proposed, but no proposal has been made on a casing structure that is lightweight and maintains high rigidity and can be manufactured.
[0003]
[Problems to be solved by the invention]
By forming a heat pipe flow path inside the case to take heat generated by the high heat generating element, heat is transferred to the entire surface of the case to dissipate heat, and the flow path formed at the same time reduces the thickness and rigidity. Plan.
[0004]
[Means for Solving the Problems]
The object is to provide a cooling system used in an electronic apparatus having a display-side casing that opens and closes with respect to a casing on which a heating element is mounted, and a heat receiving plate that absorbs heat generated by the heating element, and the heat receiving plate. A refrigerant that is vaporized by the absorbed heat, a pipe that forms a flow path through which the vaporized refrigerant passes, a heat radiating member that changes the refrigerant from gas to liquid, and the refrigerant that has become liquid as a heat receiving plate A liquefied flow path pipe to be returned, and the heat dissipating member is formed by a flow path that radiates heat by the surface of the casing by being attached to a predetermined surface of the display side casing, and the heat receiving plate The heat dissipating member, the vaporization channel pipe, and the liquefaction channel pipe are connected to each other to form a heat pipe structure in which the refrigerant circulates. The portion deformed by opening and closing the flexible connector is a flexible connector, and the diameter of the liquefied flow channel pipe that is the inflow side of the refrigerant to the heat receiving plate is the vaporization flow that is the outflow side of the refrigerant from the heat receiving heat plate. This is achieved by making it smaller than the diameter of the road pipe.
[0006]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0007]
FIG. 1 shows an electronic device casing according to the present invention having a heat pipe integrated structure. In other words, the housing is formed by joining combined Ri adhered two plates, by locally deforming the inner plates 1 of the housing to form a space serving as a flow path of refrigerant between the two plates The heat pipe 3 is formed. In this case, the portion of the heat pipe formed in a convex shape also serves as a rib for increasing the strength of the housing, and has both the features of acceleration of heat transfer and rigidity. For this reason, it is possible to make the thickness of the plate 1 and the plate 2 1 mm or less, respectively. Furthermore, it has a structure with screw holes for suspending display devices such as circuit boards and liquid crystal displays inside the housing, realizing a complicated housing shape comparable to conventional plastic molded products and die-cast metal housings. Is possible.
[0008]
FIG. 2 is a sectional view in the longitudinal direction near the center of the housing shown in FIG. The inner plate 1 and the outer plate 2 are joined by a brazing material or an adhesive. A coolant such as water is enclosed in the flow path of the heat pipe 3 for use.
[0009]
Next, an example of the arrangement of the cooling system in the case where the heat pipe integrated structure is used for an electronic device will be described with reference to FIG. That is, the cooling system shown in FIG. 3 includes the heat receiving plate 6, the heat pipes 7 and 10 extending from the heat receiving plate, and the heat pipe 3 and the flexible connectors 9 and 11 formed integrally with the housing on the display 8 side. In FIG. 3, a heat pipe-integrated housing is used as a housing component on the display side. The heat generated by the element 4 on the circuit board attached to the keyboard side is absorbed from the heat receiving plate 6 through the flexible contact. The absorbed heat vaporizes the refrigerant sealed in the heat pipe 7 on the keyboard side, and reaches the heat pipe 3 formed in the housing through the heat pipe 7 and the flexible connector 9. When the vaporized refrigerant passes through the heat pipe 3, it is cooled by heat radiation from the surface of the housing, and the refrigerant changes from gas to liquid. The liquid refrigerant is returned to the heat receiving plate through the flexible connector 11 and the heat pipe 10, and the same cycle is repeated thereafter. Here, in order to facilitate the flow of the vaporized refrigerant in the direction of the heat pipe 7 and to make the direction of circulation of the refrigerant constant, the cross-sectional area of the heat pipe 7 is heated as shown in FIG. What is necessary is just to make it larger than the cross-sectional area of the pipe 10. FIG. In addition, as shown in FIG. 6 (b), a stable circulation of the refrigerant can be obtained by using the flow resistance nozzle 16 so as to easily flow in the direction of the heat pipe 7.
[0010]
In addition, although the example showed the effect when the function as a heat pipe was considered, it is also possible to use the heat pipe integrated in the housing as a refrigerant flow path for circulating it by a pump or the like. .
[0011]
Next, an example of a process for processing the case in which the heat pipes shown in FIG. 1 are integrated will be described with reference to FIGS. That is, using two plates 1 and 2 as shown in FIG. 4A, a projection for inserting a rod 13 with a screw hole for fastening a display is formed on the plate 1 by press working. A mold release agent 21 such as ceramic powder is selectively applied or printed so as to correspond to the shape of the heat pipe (FIG. 4B). Next, as shown in FIG. 4C, an adhesive such as a brazing material is inserted between the two plates, and after superposition, they are heat treated and bonded. At this time, the two plates are not joined to the portion to which the release agent is applied. In addition, the rod 13 with a screw hole for fixing a circuit board and a display can be simultaneously inserted and fixed to a burring protrusion hole. Next, as shown in FIGS. 4D and 4E, the outer peripheral skirt portion of the joined plate is composed of a mold (an upper punch 30, a wrinkle holding punch 31, a die 32, and a lower punch 33 attached to a press device. Molded). Thereafter, high pressure air is introduced into the unjoined portion, and the inner plate 2 is stretched and formed. In this case, the amount of overhang is defined by the size of the recess 34 formed on the lower surface of the upper punch 30.
[0012]
In the process, the two plates are joined using a brazing material, but joining with an adhesive is also possible. Further, in the embodiment, the flow path of the refrigerant of the heat pipe is formed by introducing high-pressure gas at the final stage, but the flow path is pressed at the stage of forming the screw holed rod 13 and then brazed. It is also possible.
[0013]
Next, the connection relationship between the heat pipe formed on the display cover and each heat pipe that conducts heat from the element will be described in detail. Fig.5 (a) is a side view of a cooling system, FIG.5 (b) shows a top view. Wide and thin heat pipes 7 and 10, a flexible connector 9 and a heat receiving plate 6 are employed so as to reduce the thickness of the electronic device and not lower the cooling performance. That is, the cross section of each part is rectangular. The flexible connector 9 has a bellows structure rich in elasticity, and can be easily deformed following the opening / closing operation of the display. In the heating element 4 attached to the circuit board in FIG. 5A, heat is transferred to the heat receiving plate 6 through the flexible contact 15 having good thermal conductivity such as silicon resin. The heat receiving plate 6 and the heat pipes 7 and 10 can be joined by welding or brazing. Moreover, joining of the heat pipe 7, the flexible connector 9, and the housing with the heat pipe can also be performed by welding or brazing. In addition, the material of the heat pipes 7 and 10, the flexible connector 9, the heat receiving plate 6, and the heat pipe 3 can be made of stainless steel, aluminum, or copper metal. However, a polymer-based flexible tube can also be adopted as the flexible connector, and a commercially available joint can be used for connection to the heat pipe.
[0014]
FIG. 7 shows another example of a housing structure in which heat pipes are integrated. Although a circulation type heat pipe flow path is formed in the housing shown in FIG. 1, in FIG. 7, there is only one place where the flexible connector is attached to connect to the heat receiving plate. That is, FIG. 8 shows the arrangement of the cooling system when the housing shown in FIG. 7 is used. In this case, the refrigerant vaporized by the heat of the element moves to the heat pipe 3 in the heat pipe 7 and the refrigerant cooled and liquefied by the housing coexists. The connection state of the heat pipes in the heat receiving plate in this case is shown in FIG. The refrigerant vaporized by the heat receiving plate 6 moves to the housing side along the upper portion of the heat pipe 7, but the refrigerant cooled and liquefied by the housing returns to the heat receiving plate along the lower portion of the heat pipe 7, and performs the same cycle. repeat.
[0015]
In the embodiment, the heat pipe is formed only for the housing on the display side, but it is also possible to form the heat pipe on the housing on the side where the high heat generating element is mounted. The configuration of the cooling system when a heat pipe is formed in the keyboard-side casing will be described. That is, in FIG. 10, the heat generated by the high heat generating element 4 is transferred from the heat pipe 7 to the heat pipe formed in the keyboard side housing via the flexible connector 9. When the cooling system in FIG. 3 or FIG. 8 is employed, the flexible connector is subjected to bending deformation each time the display is opened and closed, so that the flexible connector is required to have high strength reliability. As shown in FIG. 10, this problem can be solved by adopting a housing with a heat pipe on the side where the heat generating element exists. FIG. 11 shows the keyboard-side casing structure shown in FIG. 10, and a rod 13 with screw holes for fixing a circuit board, a hard disk or the like using the process shown in FIG. 4 as with the display casing. Can be formed. In FIG. 11, the windows 60, 61, 62 on the side wall of the housing for inserting an IC card or a floppy disk device can be formed by press punching or the like.
[0016]
FIG. 12 shows a schematic mounting structure when a heating element is inserted and fixed in a display-side casing in which a heat pipe is formed. That is, the circuit board 40 in which the high heat generating element 4 is incorporated in addition to the display 8 is fixed to the casing, and then covered with the casing cover 17 on the display side. A connector 18 for electrically connecting the circuit board to the circuit board on the keyboard side is formed. In addition, the refrigerant can be completely sealed by means such as welding after filling the refrigerant in the internal space of the heat pipe and then crimping and sealing the base part 19. Although only one base part is shown in the figure, the refrigerant sealing operation is facilitated by providing two base parts.
[0017]
Next, means for transferring heat from the heating element to the heat pipe will be described with reference to the cross-sectional view of FIG. That is, the heat from the element 4 is transmitted to the heat pipe through the flexible contact 15. By adopting the flexible contact 15, it is possible to make the element less susceptible to external impacts and to improve the heat transfer characteristics by improving the adhesion with the element.
[0018]
In addition, although description was abbreviate | omitted in the Example, it is possible to form the fine groove | channel (wick) which makes it easy for a refrigerant | coolant to return to a heat receiving part using the capillary phenomenon on the inner surface of a heat pipe. In the embodiment, the cooling system transmits heat from the element only to the case with the heat pipe of the present invention. However, a part of the heat generation amount is given to the conventional case on which the high heating element is mounted. If the heat is transferred and dispersed, it is possible to cool the element having a higher calorific value.
[0019]
As is clear from the above embodiments, the present invention can reduce the thickness while maintaining the rigidity of the casing, and can cool the high heat generating element by the integrated heat pipe.
[0020]
【The invention's effect】
According to the present invention, it is possible to obtain a heat pipe having an inexpensive structure for efficiently transferring heat from a high heating element such as a CPU to a narrow space of a notebook type workstation or a personal computer.
[Brief description of the drawings]
FIG. 1 is a perspective view of a housing integrated with a heat pipe.
FIG. 2 is a cross-sectional view of the housing of FIG.
FIG. 3 is a perspective view of an electronic apparatus in which a cooling system is incorporated using the housing of the present invention.
FIG. 4 is an explanatory diagram of a heat pipe processing process.
FIG. 5 is an explanatory diagram of a cooling system.
FIG. 6 is an explanatory diagram of an element heat receiving unit.
FIG. 7 is a perspective view of a housing according to a second embodiment of the present invention.
FIG. 8 is a perspective view of an electronic device in which a heat pipe housing is mounted and a cooling system is incorporated.
FIG. 9 is an explanatory diagram of connection of heat pipes in a heat receiving unit.
FIG. 10 shows a personal computer when a cooling system is configured only on the keyboard side.
FIG. 11 is a perspective view of a keyboard-side housing with an integrated heat pipe.
FIG. 12 is an explanatory diagram of component assembly when a heat pipe is integrated with the display-side casing.
FIG. 13 is a cross-sectional view of a means for transferring heat from the element to a display-side housing integrated with a heat pipe.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Inner plate, 2 ... Outer plate, 3 ... Heat pipe flow path, 13 ... Rod with screw hole.

Claims (2)

In a cooling system used for an electronic device having a display-side casing that opens and closes with respect to a casing on which a heating element is mounted,
  A heat receiving plate that absorbs heat generated by the heat generating element, a refrigerant that is vaporized by the heat absorbed by the heat receiving plate, a pipe that forms a flow path through which the vaporized refrigerant passes, and the refrigerant is a gas A heat dissipating member that changes from a liquid to a liquid, and a liquefying flow path pipe that returns the liquid refrigerant to a heat receiving plate, and the heat dissipating member is attached to a predetermined surface of the display-side casing. Is constituted by a flow path that radiates heat by the surface of the housing,
  The heat receiving plate, the heat radiating member, the vaporization passage pipe, and the liquefaction passage pipe are connected to each other to form a heat pipe structure in which the refrigerant circulates. The deformable part is a flexible connector,
  An electronic apparatus characterized in that a diameter of a liquefied flow path pipe on the refrigerant inflow side to the heat receiving plate is smaller than a diameter of a vaporization flow path pipe on the refrigerant outflow side from the heat receiving heat plate. Cooling system used. In the cooling system used for the electronic device of Claim 1 ,
A nozzle is provided that makes the inlet of the liquefied flow path pipe, which is the inflow side of the refrigerant, into the heat receiving plate smaller than the outlet of the vaporization flow path pipe, which is the outflow side of the refrigerant, from the heat receiving heat plate. Cooling system used for electronic equipment.

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