Abstract:
According to a water pillow for heat radiation for touching a heat generating object, absorbing heat from the heat generating object and radiating heat by cooling liquid that circulates inside the water pillow, said device includes an inflow inlet for flowing the cooling liquid inside the water pillow, a drain outlet for flowing the cooling liquid out of inside the water pillow, a plurality of cooling fins spoke wise disposed on a first plane constituting a cavity inside the water pillow where the cooling liquid circulates and an impeller for circulating in a whirl the cooling liquid disposed on a second plane opposed in parallel or almost parallel with the first plane.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2008-190045, filed on Jul. 23, 2008, the entire contents of which are incorporated herein by reference. 
       FIELD 
       [0002]    The embodiment discussed herein is related to a water pillow for heat radiation for cooling heat generated by a target. 
       BACKGROUND 
       [0003]    Recently, thanks to the improvement of a semiconductor integration technology, the high-density of integrated circuits and the like has been made possible and the improvement of the functions of an integrated circuit used in an operation device and the like has been promoted. However, the amount of generated heat of integrated circuits and the like increased compared with conventional one. A cooling device for cooling this generated heat is widely used. 
         [0004]    Related to the above technology, for example, the cooling device of heat radiating electronic components for receiving heat by a contact type liquid-cooling/heat-receiving pump which can be small-sized, thin and simple-structured while cooling efficiency is improved is known. 
         [0005]    Also, a liquid cooling system for improving cooling performance by increasing heat conductivity by striking cooling liquid against a heat sink, generating collision jet flow and speeding up liquid current is known. 
         [0006]    Patent document 1: Japanese Patent Laid-open Application No. 2004-285888 
         [0007]    Patent document 2: Japanese Patent Laid-open Application No. 2005-317797 
         [0008]    Patent document 3: Japanese Patent Laid-open Application No. 2006-039663 
       SUMMARY 
       [0009]    However, demand for a higher-cooling efficiency cooling device is increasing. In order to improve cooling efficiency, a water-cooling type device is effective. Thus, higher-cooling efficiency water pillow for heat radiation is desired. 
         [0010]    In order to solve the above-described problem, the water pillow of this invention is a water pillow for heat radiation for radiating heat by touching a heat generating object, absorbing heat from the heat generating object and radiating heat by cooling liquid circulating inside the water pillow and the water pillow includes an inflow inlet for flowing the cooling liquid inside the water pillow, a drain outlet for flowing the cooling liquid out of inside the water pillow, a plurality of cooling fins spokewise disposed on a first plane constituting a cavity inside the water pillow where the cooling liquid circulates and an impeller for circulating the cooling liquid in a whirl disposed on a second plane opposed in parallel or almost parallel with the first plane. 
         [0011]    The object and advantages of the embodiment will be realized and attained by means of the elements and combinations particularly pointed out in the claims. 
         [0012]    It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the embodiment, as claimed. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0013]      FIG. 1  is a configuration example of a cooling device according to this preferred embodiment; 
           [0014]      FIG. 2  is a cross-sectional view obtained by cutting along A-A′ of the water pillow illustrated in  FIG. 1  on a plane in parallel with the bottom surface d; 
           [0015]      FIG. 3  is a variation of cooling fins disposed on the bottom surface d of the water pillow illustrated in  FIG. 1 ; 
           [0016]      FIG. 4  is a cross-sectional view obtained by cutting cooling fins by a plane orthogonal to the bottom surface d of the water pillow and cooling fins illustrated in  FIG. 1 ; 
           [0017]      FIG. 5  illustrates variations of cooling fins according to this preferred embodiment (No. 1); 
           [0018]      FIG. 6  illustrates variations of cooling fins according to this preferred embodiment (No. 2); and 
           [0019]      FIG. 7  illustrates a variation of cooling fins according to this preferred embodiment (No. 3). 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0020]    One example of the preferred embodiments of the present invention will be explained with reference to  FIGS. 1 through 7 . 
         [0021]      FIG. 1  is an example of configuration of a cooling device  100  according to this preferred embodiment. 
         [0022]    The cooling device  100  illustrated in  FIG. 1  includes a water pillow  101  having cavity, inside which cooling water circulates, an impeller  102  for circulating the cooling water in a whirl in the cavity, a motor  103  for driving the impeller  102  and a cooling water circulator  104  for supplying cooling water discharged from a drain outlet b to a feeding inlet a. 
         [0023]    The water pillow  101  is a rectangular parallelepiped made of a material having a high heat conductivity, such as copper or the like. It has rectangular parallelepiped cavity inside and can feed and discharge cooling water from the feeding inlet a and the drain outlet b, respectively. 
         [0024]    The impeller  102  is provided at the center of the top surface c of the cavity inside the water pillow  101 , and when the impeller  102  is rotated by the motor  103 , the cooling water inside the cavity can be circulated in a whirl. 
         [0025]    Furthermore, the cooling fins  105  that are spokewise disposed around the neighborhood of the impeller  102  is provided on the bottom surface d of the cavity inside the water pillow  101 , and heat conducted from a heat generating object  106  via a contact part e is radiated into the cooling water via the cooling fins  105 . 
         [0026]    The cooling water circulator  104  includes, for example, a pump for circulating cooling water in the direction of the feed inlet a, a reserve tank for storing a certain capacity of cooling water and a radiator for cooling cooling water discharged from the drain outlet b. 
         [0027]    Although in this preferred embodiment having the above configuration, the case in which cooling water is used is explained, the invention is not limited to this type of cooling water and various types of cooling liquid can be also used, as requested. Although, in this preferred embodiment, the shapes of the water pillow  101  and the cavity inside the water pillow are rectangular parallelepiped, the invention is not limited to this shape and the shape can be appropriately determined according to the shape of the heat generating object  106 , the disposition environment of the cooling device  100  and the like. 
         [0028]      FIG. 2  is a cross-sectional view obtained by cutting along A-A′ of the water pillow  101  illustrated in  FIG. 1  on a plane in parallel with the bottom surface d. 
         [0029]    As illustrated in  FIG. 2 , a plurality of cooling fins  105  is disposed spokewise (or almost spokewise) on the bottom surface d of the cavity and is fixed on the water pillow  101 . Then, when the impeller  102 , which is not illustrated in  FIG. 2 , is rotated in the direction of an arrow x, cooling water filled in the cavity is circulated in a whirl in the direction of the arrow x. 
         [0030]    Then, the cooling water strikes against the cooling fins  105  at perpendicular or near-perpendicular incident angle. In another words, the cooling water collide with the cooling fins  105  at the maximum speed. As a result, heat can be efficiently conducted by convection. 
         [0031]    Furthermore, the cooling water that has collided with the cooling fins  105  flows in the direction of an arrow y along the cooling fins  105  and when reaching the outer circumference of the spokes, it circulates in a y′ direction and also circulates in a whirl according to the rotation of the impeller  102 . Therefore, the cooling water can smoothly circulate in a whirl. As a result, since cooling liquid can be applied to the cooling fins  105  at higher speed, a high heat radiation effect on the cooling water can be obtained. 
         [0032]    Naturally, the number of the cooling fins  105  is not limited in  FIG. 2  and can be determined according to the size, shape and the like of the cooling device  100 . 
         [0033]    Although linear cooling fins  105  are spokewise disposed on the button surface d in  FIG. 2 , for example, as illustrated in  FIG. 3 , each of the cooling fins  105  spokewise disposed can also form a flexibly curved line along the circulating direction of the cooling water (a circular arc or almost circular arc). 
         [0034]    Thus, since the cooling water that has collided with the cooling fins  105  more smoothly flows along the cooling fins  105  in the direction of an arrow z, the cooling water can more smoothly circulate in a whirl. As a result, since the cooling water can be struck against the cooling fins  105  at higher speed, the high radiation effect of the cooling water can be obtained. 
         [0035]      FIG. 4  is a cross-sectional view obtained by cutting cooling fins  105  along a plane orthogonal to the bottom surface d of the water pillow  101  and the cooling fins  105  (for example, the cross-sectional view at B-B′ illustrated in  FIG. 2 ). 
         [0036]    As illustrated in  FIG. 4 , the cooling fins  105  are fixed in a state where the cooling fins  105  are slightly inclined from a state perpendicular to the bottom surface d toward the circulating direction of the cooling water. Specifically, the cooling fins  105  are fixed in such a state that the cooling fins  105  on the side where the cooling water directly collides with the cooling fins  105  and the bottom surface d forms an elevation angle α. 
         [0037]    Thus, the cooling water that is circulated in a whirl by the rotation of the impeller  102  provided on the top surface c is applied to the cooling fins  105  at a perpendicular or nearly perpendicular incident angle. In another words, the cooling water collides with the cooling fins  105  at the maximum speed. As a result, since the heat conductivity by convection is improved, the water pillow  101  can obtain a higher radiation effect. 
         [0038]    The above-described elevation angle α can be appropriately determined taking into consideration the size of the cavity of the water pillow  101 , the height of the cooling fins  105  and the like. Although the cooling fins  105  are fixed on its bottom surface d in such a way as illustrated in  FIG. 4  in the water pillow  101  according to this preferred embodiment, it can be fixed in such a way as to be orthogonal to the bottom surface d. 
         [0039]    Although belt-like or plane plate-shaped cooling fins  105  are used in the above explanation, one having the following shapes can be also used. 
         [0040]      FIGS. 5 and 6  illustrate examples of variation of cooling fins according to this preferred embodiment. 
         [0041]      FIG. 5  illustrates the side view of cooling fins  501  fixed on the bottom surface d, the top view in the case where the cooling fins  501  illustrated in this side view is cut along C-C′ the side view in the case where the cooling fins  501  is cut at D-D′ (on the radial center side) and the side view in the case where the cooling fins  501  is cut along E-E′ (on the radial outer circumference side). 
         [0042]    When viewed from the side as illustrated in  FIG. 5 , the cooling fins  501  forms a rectangle. The cross-section obtained by cutting the C-C′ of the cooling fins  501  along a plane in parallel with the bottom surface d forms a straight line having certain thickness. 
         [0043]    The cross-section obtained by cutting the D-D′ and E-E′ of the cooling fins  501  along a plane orthogonal to the bottom surface d forms a circular arc-shaped or almost circular arc-shaped gently curved line and a side forming an elevation angle with the bottom surface d becomes concave. Thus, the water current of the cooling water coming toward the cooling fins  501  can be surely caught and the cooling water can circulate into the root portion of the cooling fins  501 . Therefore, the heat conductivity from the cooling fins  501  to the cooling water can be improved. As a result, the cooling efficiency can be improved. 
         [0044]    Like  FIG. 5 ,  FIG. 6  illustrates the side view of cooling fins  601  fixed on the bottom surface d, the top view in the case where the cooling fins  601  is cut at F-F′, the side view in the case where the cooling fins  601  is cut along G-G′ (on the radial center side) and the side view in the case where the cooling fins  601  is cut along H-H′ (on the radial outer circumference side). 
         [0045]    When viewed from the side as illustrated in  FIG. 6 , the cooling fins  601  forms a rectangle. The cross-section obtained by cutting along the F-F′ of the cooling fins  501  on a plane in parallel with the bottom surface d forms a straight line having certain thickness. 
         [0046]    Like in  FIG. 5 , the cross-section obtained by cutting along the G-G′ of the cooling fins  601  on a plane orthogonal to the bottom surface d forms a surface slightly curved in a form of circular arc or almost circular arc and a side forming an elevation angle with the bottom surface d becomes concave. However, the cross-section obtained by cutting along the H-H′ of the cooling fins  601  on a plane orthogonal to the bottom surface d forms a plane plate forming an elevation angle with the bottom surface d. In another words, it forms a shape gently shifting from a curved surface in a form of circular arc or almost circular arc to a plane plate as the position moves from the center side of the radiated arrangement to its outer circumference side. 
         [0047]    Each of the cooling fins  105  illustrated in  FIGS. 5 and 6  can also form a shape as illustrated in  FIG. 3 , that is, each of the C-C′ and F-F′ sections forms a circular arc or almost circular arc. In the side view illustrated in  FIGS. 5 and 6 , height h can also increase from the center toward the outer circumference. The H-H′ cross-section can also form a circular arc or almost circular arc having a large radius. 
         [0048]    In the above explanation, all the heights (for example, h illustrated in  FIGS. 5 and 6 ) (hereinafter simply called “height” from the bottom surface d of the cooling fins  105  provided for the cooling device  100  are constant, however, their heights can also differ based on a certain rule. 
         [0049]      FIG. 7  illustrates a variation of the cooling fins  105  according to this preferred embodiment. 
         [0050]    The cooling fins  701  illustrated in  FIG. 7  are composed of three types of cooling fins having different height. In the cooling fins  701 , a cooling fin  701   a  whose height is low, a cooling fin  701   b  whose height is middle and a cooling fin  701   c  whose height is high are alternately disposed in this order in the whirly circulation direction of the cooling water repeatedly. 
         [0051]    Thus, variation in the water pressure and the amount of water when the cooling water is applied to each cooling fin  105  can be suppressed. 
         [0052]    Also, even when the cooling fins  701  are somewhat crowded, the heat conductivity from the cooling fins  701  to the cooling water can be improved since the cooling water circulating in a whirl is directly applied to each cooling fin  701 . As a result, the cooling efficiency can be improved. 
         [0053]    Although three types of cooling fins  701  each having different height are used in  FIG. 7 , the number of types is not limited to this. Although three types of cooling fins  701  having different heights of “low”, “middle” and “high” are disposed in the whirly circulating direction of the cooling water in this order, the invention is not limited to this order. The cooling fins  701  having appropriate heights can be disposed in an appropriate order, as requested. 
         [0054]    As illustrated in  FIGS. 2 and 3 , when the cooling fins  105  are spokewise (or almost spokewise) disposed on the bottom surface d of the cavity and the cooling water is circulated in a whirl by the impeller  102  on the top surface c, the cooling water can be applied to all the cooling fins  105  at a perpendicular or nearly perpendicular angle at all the positions. Specifically, since the cooling water collides with the cooling fins  105  at the maximum speed, the heat conductivity by convection can be improved and a high cooling efficiency can be obtained. 
         [0055]    As illustrated in  FIG. 3 , by forming the cooling fins  105  spokewise disposed in a form of gentle curvature (a circular arc or a nearly circular arc) along the circulating direction of the cooling water, the cooling water is smoothly led along the radial outer circumference fins after colliding with the cooling fins  105 . Therefore, the cooling water inside the cavity can be smoothly circulated in a whirl. As a result, the speed of the cooling water at the time of colliding with the cooling fins  105  can be improved. Therefore the cooling efficiency can be improved. 
         [0056]    Furthermore, as illustrated in  FIG. 4 , by fixing the cooling fins  105  in such a state that the cooling fins  105  on the side where the cooling water directly collides with the cooling fins  105  and the bottom surface d forms an elevation angle α, the cooling water is applied to the cooling fins  105  perpendicularly to the cooling fins  105 . Therefore, the cooling water collides with the cooling fins  105  at the maximum speed at all the positions. As a result, the heat conductivity by convection can be improved and a higher cooling efficiency can be obtained. 
         [0057]    According to this preferred embodiment, since cooling fins are spokewise disposed on a first plane constituting a cavity inside for circulating cooling water and an impeller disposed on a second plane opposed in parallel or almost parallel with the first plane circulates the cooling water filled in the cavity in a whirl, the cooling water circulating in a whirl is applied to the cooling fins at an incident angle perpendicular or nearly perpendicular to the cooling fins. Therefore, the cooling water can be applied to the cooling fins at higher speed. Therefore, heat conductivity by convection can be improved and cooling efficiency can be improved. 
         [0058]    As explained above, by the disclosed water pillow for heat radiation, the cooling efficiency of a device to which the water pillow is applied can be improved. 
         [0059]    All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a depicting of the superiority and inferiority of the invention. Although the embodiments of the present inventions have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.