JP5423625B2 - Cooling device using EHD fluid - Google Patents

Description

  The present invention relates to a cooling device that cools a heating element using an EHD fluid.

  Conventionally, Patent Document 1 discloses a cooling device that cools a heating element using an EHD fluid that flows by an electrohydrodynamic (EHD for short) effect. Specifically, a pipe is provided between a cooling part to which heat of the heating element is transmitted and a heat radiating part that releases the heat to the outside, and the EHD fluid is filled in the cooling part, the heat radiating part, and the pipe. An electrode that causes the EHD fluid to flow by applying a voltage to is used as a pump in a cooling unit, a heat dissipation unit, or a piping unit. The pump cools the heating element by circulating the EHD fluid.

JP 2000-2222072 A JP-A-11-125173

  However, according to the inventors' investigation, it has been found that there is room for more efficient cooling of the heating element by improving the arrangement of the pump as described above.

  In view of the above points, the present invention provides a cooling device that cools a heating element using an EHD fluid, and by devising the arrangement of a pump that flows the EHD fluid by applying a voltage to the EHD fluid, the cooling efficiency of the heating element The purpose is to increase the conventional level.

  The invention according to claim 1 for achieving the first object is to cool a heating element (2 to 4) using an EHD fluid flowing by an electrohydrodynamic (EHD) effect. A cooling device (12) facing the heating element (2-4) and receiving heat generated by the heating element (2-4) by heat conduction; and heat to the outside of the cooling device A heat radiating part (13) to be released, and a connecting part (11) connected to the cooling part (12) and the heat radiating part (13) and for transporting heat from the cooling part (12) to the heat radiating part (13). ), And in the inside of the connecting portion (11), an upstream connecting flow path (111) for flowing an EHD fluid from the heat radiating portion (13) into the cooling portion (12), and an EHD fluid For flowing from the cooling part (12) into the heat radiation part (13) A downstream connection flow path (112), and the EHD fluid is communicated with the upstream connection flow path (111) and the downward connection flow path (112) inside the cooling section (12). It flows from the ascending connection channel (111) to the descending connection channel (112), and has a portion that is thinner than the ascending connection channel (111) than the descending connection channel (112) and has a higher flow rate of EHD fluid. In-cooling section flow paths (121, 122, 123, 124, 125a to 125g, 126) are formed, and in the heat dissipation section (13), the upstream connection flow path (111) and the downstream connection flow path (112). ) In the heat radiation portion (131, 132, 133, 134, 135a to 135g) for allowing the EHD fluid to flow from the downstream connection channel (112) to the upstream connection channel (111) is formed. The upstream connection flow path (111), the cooling section internal flow path (121, 122, 123, 124, 125a to 125g, 126), the downward connection flow path (112), and the heat dissipation section internal flow path (131, 132). , 133, 134, 135 a to 135 g), a pump (20) that causes the EHD fluid to flow by applying a voltage to the EHD fluid is disposed at each of the plurality of positions inside the flow path. 20), the number of pumps (20) per unit volume in the cooling-unit internal flow paths (121, 122, 123, 124, 125a to 125g, 126) is determined by the upstream connecting flow of the connecting portion (11). A cooling device characterized in that the number of pumps (20) per unit volume in the passage (111) and in the downstream connecting flow path (112) is larger. .

  In this way, in the cooling part internal flow paths (121, 122, 123, 124, 125a to 125g, 126), the cross-sectional area of the flow path is made smaller than that of the upstream connection flow path (111) and the downstream connection flow path (112). As a result, the flow rate of the EHD fluid can be increased and more flow paths can be installed in the cooling unit. Therefore, the area of the EHD fluid and the cooling portion where the EHD fluid contacts is increased, and the heat transfer rate is improved by increasing the flow velocity, thereby increasing the cooling efficiency.

  In such a situation, the upstream connection flow path (111), the cooling part internal flow path (121, 122, 123, 124, 125a to 125g, 126), the downward connection flow path (112), and the heat dissipation part internal flow path (131, 132). Among the plurality of pumps (20) in the flow path consisting of 133, 134, 135a to 135g), the pumps per unit volume in the cooling section flow paths (121, 122, 123, 124, 125a to 125g, 126) The number of pumps (20) is set to be larger than the number of pumps (20) per unit volume in the ascending connection channel (111) and the descending connection channel (112) of the connecting part (11), so that the cooling can be performed. The flow rate in the section (12) can be increased to improve the heat transfer coefficient between the EHD fluid and the cooling section in contact with the EHD fluid43. As a result, the cooling efficiency of the heating elements (2 to 4) can be increased as compared with the conventional case.

  The invention according to claim 2 for achieving the first object cools the heating element (2-4) by using an EHD fluid that flows by an electrohydrodynamic (EHD) effect. A cooling unit (12) facing the heating element (2-4) and receiving heat generated by the heating element (2-4) by heat conduction, and outside the cooling apparatus A heat dissipating part (13) for releasing heat and a connecting part connected to the cooling part (12) and the heat dissipating part (13) for transporting heat from the cooling part (12) to the heat dissipating part (13). (11), and an upstream connection flow path (111) for flowing an EHD fluid from the heat radiation part (13) into the cooling part (12) inside the connection part (11), EHD fluid is allowed to flow from the cooling part (12) into the heat dissipation part (13). And a downstream connection flow path (112) for forming an EHD fluid by communicating with the upstream connection flow path (111) and the downward connection flow path (112) in the cooling section (12). In the cooling section (121, 122, 123, 124, 125a to 125g, 126) for flowing the gas from the upstream connecting flow path (111) to the downstream connecting flow path (112) is formed, and the heat radiating section (13 ), The EHD fluid is allowed to flow from the downstream connection channel (112) to the upstream connection channel (111) by communicating with the upstream connection channel (111) and the downstream connection channel (112). In the heat dissipating section (131, 132, 133, 134, 135a to 135g) having a portion that is narrower than the descending connection channel (112) and faster in flow rate of EHD fluid than the ascending connection channel (111). Formed, the upstream connection flow path (111), the cooling section internal flow path (121, 122, 123, 124, 125a to 125g, 126), the downward connection flow path (112), and the heat dissipation section internal flow path (131, 132, 133, 134, 135 a to 135 g), a pump (20) for causing the EHD fluid to flow by applying a voltage to the EHD fluid is disposed at each of a plurality of positions inside the flow path. (20), the number of pumps (20) per unit volume in the heat dissipation section flow paths (131, 132, 133, 134, 135a to 135g) is the ascending connection flow path of the connection section (11). (111) and the number of pumps (20) per unit volume in the downstream connecting flow path (112)

  As described above, in the heat radiating section internal flow passages (131, 132, 133, 134, 135a to 135g), the flow passage cross-sectional area is made smaller than that of the upward connection flow passage (111) and the downward connection flow passage (112). It is possible to increase the flow rate of the EHD fluid and install more flow paths in the cooling unit. For this reason, the area of the EHD fluid and the cooling part in contact with the EHD fluid increases, and the heat transfer efficiency is improved by increasing the flow velocity, thereby increasing the heat dissipation efficiency.

  In such a situation, the upstream connection flow path (111), the cooling part internal flow path (121, 122, 123, 124, 125a to 125g, 126), the downward connection flow path (112), and the heat dissipation part internal flow path (131, 132). Among the plurality of pumps (20) in the flow path composed of 133, 134, 135a to 135g), the pump (20 per unit volume) in the heat dissipation section flow path (131, 132, 133, 134, 135a to 135g) )) More than the number of pumps (20) per unit volume in the upstream connection flow path (111) and the downward connection flow path (112) of the connection portion (11). 13) It is possible to increase the heat flow rate in the interior and improve the heat transfer coefficient between the EHD fluid and the cooling part in contact with the EHD fluid. As a result, the heat radiation efficiency in the heat radiating section (13) can be increased, and as a result, the cooling efficiency of the heating elements (2 to 4) can be increased as compared with the conventional art.

  In addition, the invention according to claim 3 is the cooling device according to claim 1 or 2, wherein each of the plurality of pumps (20) has a pointed electrode (21) and a slit electrode (22), The pointed electrode (21) is tapered toward the slit electrode (22), and the slit electrode (22) is slit-shaped, so that the position of the pump (20) The flow path is further narrowed.

  Thus, the slit electrode (22) constituting the pump (20) further narrows the flow path at the position of the pump (20), thereby increasing the flow speed of the flow path and the flow speed. Since the pump (20) is driving the EHD fluid at a position where the EHD fluid is raised, the flow rate is further increased, the heat transfer rate of the EHD fluid and the portion contacting the EHD fluid is improved, and a higher heating element (2-4) ) Cooling efficiency can be realized.

  The invention according to claim 4 for achieving the second object cools the heating element (2-4) by using an EHD fluid flowing by an electrohydrodynamic (abbreviated EHD) effect. A cooling unit (12) facing the heating element (2-4) and receiving heat generated by the heating element (2-4) by heat conduction, and outside the cooling apparatus A heat dissipating part (13) for releasing heat and a connecting part connected to the cooling part (12) and the heat dissipating part (13) for transporting heat from the cooling part (12) to the heat dissipating part (13). (11), and an upstream connection flow path (111) for flowing an EHD fluid from the heat radiation part (13) into the cooling part (12) inside the connection part (11), EHD fluid is allowed to flow from the cooling part (12) into the heat dissipation part (13). And a downstream connection flow path (112) for forming an EHD fluid by communicating with the upstream connection flow path (111) and the downward connection flow path (112) in the cooling section (12). In the cooling section (121, 122, 127, 128) for flowing the water from the upstream connecting flow path (111) to the downstream connecting flow path (112), and the internal cooling section flow paths (121, 122, 127, 128). ) And a tank (129) for temporarily storing the EHD fluid, and the heat dissipating section (13) includes the upstream connecting channel (111) and the downstream connecting channel (112). Are connected to each other to form the heat dissipating section internal flow passages (131, 132, 133, 134, 135a to 135g) for flowing the EHD fluid from the downward connection flow passage (112) to the upward connection flow passage (111), The ascending From the connection flow path (111), the cooling section internal flow path (121, 122, 127, 128), the descending connection flow path (112), and the heat dissipation section internal flow path (131, 132, 133, 134, 135a to 135g) A pump (20) for causing the EHD fluid to flow by applying a voltage to the EHD fluid is disposed at each of a plurality of positions inside the flow path, and a plurality of pumps ( 20), and the plurality of pumps (20) in the tank (129) are arranged to circulate the EHD fluid in the tank (129).

  Thus, the tank (129) for temporarily storing the EHD fluid is formed in the cooling section (12), and the pump (20) is arranged so that the EHD fluid circulates in the cooling section (12). Thus, a flow different from the flow (main flow) of the EHD fluid circulating through the cooling unit (12), the coupling unit (11), and the heat radiation unit (13) can be generated in the cooling unit (12), thereby In addition, the flow rate of the EHD fluid in the cooling unit (12) can be increased independently of the main flow, and as a result, the cooling of the heating elements (2 to 4) can be realized with higher efficiency than conventional.

  The invention according to claim 5 for achieving the second object cools the heating elements (2 to 4) by using an EHD fluid flowing by an electrohydrodynamic (abbreviated EHD) effect. A cooling unit (12) facing the heating element (2-4) and receiving heat generated by the heating element (2-4) by heat conduction, and outside the cooling apparatus A heat dissipating part (13) for releasing heat and a connecting part connected to the cooling part (12) and the heat dissipating part (13) for transporting heat from the cooling part (12) to the heat dissipating part (13). (11), and an upstream connection flow path (111) for flowing an EHD fluid from the heat radiation part (13) into the cooling part (12) inside the connection part (11), EHD fluid is allowed to flow from the cooling part (12) into the heat dissipation part (13). And a downstream connection flow path (112) for forming an EHD fluid by communicating with the upstream connection flow path (111) and the downward connection flow path (112) in the cooling section (12). Are formed in the cooling unit flow passages (121, 122, 123, 124, 125a to 125g, 126) to flow the flow from the up connection flow channel (111) to the down connection flow channel (112). 13), the EHD fluid is communicated from the downstream connection channel (112) to the upstream connection channel (111) by communicating with the upstream connection channel (111) and the downstream connection channel (112). A flow path (131, 132, 127, 128) in the heat radiating section for flowing, and a tank (129) that communicates with the flow path (131, 132, 127, 128) in the heat radiating section and temporarily stores the EHD fluid. Formed The ascending connection channel (111), the cooling unit internal channel (121, 122, 123, 124, 125a to 125g, 126), the down connection channel (112), and the heat dissipation unit internal channel (131, 132, 127). 128), a pump (20) for causing the EHD fluid to flow by applying a voltage to the EHD fluid is disposed at each of the plurality of positions inside the flow path consisting of 128), and also in the tank (129), Cooling, wherein a plurality of pumps (20) are arranged, and the plurality of pumps (20) in the tank (129) are arranged to circulate an EHD fluid in the tank (129). Device.

  Thus, the tank (129) for temporarily storing the EHD fluid is formed in the heat radiating section (13), and the pump (20) is arranged so that the EHD fluid circulates in the heat radiating section (13). Thus, a flow different from the flow (main flow) of the EHD fluid circulating through the cooling unit (12), the coupling unit (11), and the heat radiating unit (13) can be generated in the heat radiating unit (13). The flow rate of the EHD fluid in the heat radiating section (13) can be increased independently of the main flow, and as a result, the cooling of the heating elements (2 to 4) can be realized with higher efficiency than conventional.

  In addition, the code | symbol in the bracket | parenthesis in the said and the claim shows the correspondence of the term described in the claim, and the concrete thing etc. which illustrate the said term described in embodiment mentioned later. .

It is a perspective view of the cooling device 1 which concerns on embodiment of this invention, and the related apparatuses 2-7. 2 is a side view of the cooling device 1. FIG. It is III-III sectional drawing of FIG. It is IV-IV sectional drawing of FIG. It is VV sectional drawing of FIG. It is VI-VI sectional drawing of FIG. It is VII-VII sectional drawing of FIG. It is an enlarged view of one pump 20 in FIG. 3, FIG. 4, or FIG. It is IX-IX sectional drawing of FIG. It is XX sectional drawing of FIG. It is sectional drawing of the cooling wall part 12e in 2nd Embodiment of this invention. It is sectional drawing of the cooling wall part 12e in 3rd Embodiment of this invention. It is XIII-XIII sectional drawing of FIG. It is the elements on larger scale of FIG.

(First embodiment)
The first embodiment of the present invention will be described below. FIG. 1 is a perspective view of the cooling device 1 according to the present embodiment and related devices 2 to 7, and FIG. 2 is a side view of the cooling device 1. The cooling device 1 of the present embodiment is a cooling device for cooling the heating elements (2 to 4) using an EHD fluid exhibiting an electrohydrodynamic (abbreviated as EHD) phenomenon as a working fluid (cooling medium). . Such an EHD fluid is a dielectric liquid that does not discharge even when a high voltage of several kV is applied, and flows under application of a voltage due to the well-known EHD effect.

  In the present embodiment, any EHD fluid may be used. For example, among EHD fluids, an electric-conjugate fluid (ECF for short) may be used. Yes.

  As the ECF, for example, as described in Patent Documents 1 and 2, the horizontal axis is the conductivity σ, the vertical axis is the viscosity η, and the graph shows the relationship between the fluid conductivity σ and the viscosity η at the operating temperature. , The point P expressed by the conductivity σ = 4 × 10 −10 S / m, the viscosity η = 1 × 100 Pa · s, the conductivity σ = 4 × 10 −10 S / m, the viscosity η = 1 × 10 −4 Pa · s. The point Q represented by s, the conductivity σ = 5 × 10 −6 S / m, and the conductivity σ located inside the right triangle having the point R represented by the viscosity η = 1 × 10 −4 Pa · s. And a compound having a viscosity η, or a mixture of two or more compounds prepared to have a conductivity σ and a viscosity η located inside the triangle. For example, dibutyldecane-dioate can be used as the ECF. A flame-retardant / non-flammable halogen-containing liquid (fluorine, chlorine, bromine, etc.) can be used as the ECF.

  The heating elements 2 to 4 are inverter switching elements (for example, IGBT (Insulated Gate Bipolar Transistor). This inverter is a vehicle driving motor that uses electric power from a running battery mounted on a hybrid vehicle or an electric vehicle. Wirings 2a to 4a and 2b to 4b for connecting to other circuits of the inverter extend from each of the heating elements 2 to 4. The cooling device 1 includes: Power is supplied from the power supply 7 through the conductors 7a and 7b, and cooling of the heating elements 2 to 4 is realized by flowing the EHD fluid using the supplied power.

  As shown in FIGS. 1 and 2, the cooling device 1 includes a metal (for example, aluminum) connecting portion 11, a cooling portion 12, and a heat radiating portion 13 formed by cutting, wet etching, plating, or the like. have. A broken line in FIG. 2 is an imaginary line indicating a boundary between the connecting portion 11, the cooling portion 12, and the heat radiating portion 13.

  The connecting part 11 is connected to the cooling part 12 and the heat radiating part 13 between the cooling part 12 and the heat radiating part 13 and is a member for transporting heat from the cooling part 12 to the heat radiating part 13 using the EHD fluid as a working fluid.

  The cooling unit 12 faces the heating elements 2 to 4 and is in contact with the heating elements 2 to 4 with the heating elements 2 to 4 interposed therebetween. Thereby, the cooling unit 12 can receive the heat generated by the heating elements 2 to 4 by heat conduction.

  The heat dissipating part 13 faces the air cooling fins 5 and 6 and is in contact with the air cooling fins 5 and 6 with the air cooling fins 5 and 6 interposed therebetween. Thus, the heat radiating unit 13 transfers heat transported from the connecting unit 11 via the EHD fluid to the air cooling fins 5 and 6, and further releases heat from the air cooling fins to the outside of the cooling device 1 by heat transfer.

  The cooling unit 12 includes a cooling base portion 12a and a plurality of cooling wall portions 12b to 12e that are integrally formed with each other. The cooling base portion 12 a is connected to the connecting portion 11.

  The plurality of cooling wall portions 12b to 12e are a plurality of rectangular parallelepiped members that rise vertically from the upper surface of the cooling base portion 12a and are arranged in parallel to each other, and sandwich the heating elements 2 to 4 between adjacent cooling wall portions. By making contact with the heating elements 2 to 4, the heat generated by the heating elements 2 to 4 is received by heat conduction. The heat conduction between the cooling wall portions 12b to 12e and the heating elements 2 to 4 may be heat conduction by direct contact, or indirect heat conduction with another material having high heat conductivity in between. It may be.

  Thus, the cooling part 12 has a plurality of cooling wall parts 12b to 12e, and the heating elements 2 to 4 are sandwiched between them, so that the contact between the heating elements 2 to 4 and the cooling part 12 is achieved. The area can be increased. The cooling base 12a is also slightly facing the heating elements 2-4.

  The heat radiating portion 13 includes a heat radiating base portion 13a and heat radiating wall portions 13b to 13d that are integrally formed with each other. The heat radiating base portion 13 a is a rectangular parallelepiped member, and one of the side surfaces is integrally connected to the connecting portion 11.

  The heat radiating wall portions 13b to 13d are a plurality of rectangular parallelepiped members that stand vertically from the upper surface of the heat radiating base portion 13a and are arranged in parallel to each other, and sandwich the air cooling fins 5 and 6 between the adjacent wall portions, respectively. , 6 conducts heat to the air cooling fins 5, 6. The heat conduction between the heat radiating wall portions 13b to 13d and the air-cooling fins 5 and 6 may be heat conduction by direct contact, or indirect heat conduction with another material having high heat conductivity in between. It may be.

  Thus, the heat radiation part 13 has a plurality of heat radiation wall parts 13b to 13d, and the air cooling fins 5 and 6 are sandwiched between them, so that the contact between the air cooling fins 5 and 6 and the heat radiation part 13 is achieved. The area can be increased. Note that the heat radiating base portion 13a also slightly contacts the air cooling fins 5 and 6 and is in contact therewith.

  FIG. 3 is a cross-sectional view taken along the line III-III in FIG. As shown in this figure, an ascending connection flow path 111 for introducing an EHD fluid from the inside of the heat radiating base 13a of the heat radiating part 13 into the cooling base 12a of the cooling part 12, and the inside of the connecting part 11, A downward connecting flow path 112 for introducing the EHD fluid from the cooling base 12 a of the cooling unit 12 and flowing it out into the heat dissipation base 13 a of the heat dissipation unit 13 is formed. The flow paths 111 and 112 are formed by cutting, wet etching, plating, or the like as described above.

  As the size of the flow paths 111 and 112, for example, the length in the vertical direction (the direction along the flow of the EHD fluid) in FIG. 3 may be a distance for connecting an appropriate arrangement of the cooling section and the heat radiating section. If the shape is a square, for example, the height of the square (vertical length in FIG. 2) is 0.05 to 10 mm, and the width of the square of the cross section (length in the horizontal direction in FIG. 3) is 0.05. -10 mm is possible.

  In addition, an ascending cooling base channel 121 and a descending cooling base channel 122 are formed in the cooling base 12a by cutting, wet etching, plating, or the like as described above. The ascending cooling base channel 121 is a channel for introducing the EHD fluid from the ascending connection channel 111 and flowing it into the cooling wall portions 12b to 12e by communicating with the ascending connection channel 111. The downstream cooling base channel 122 is a channel for introducing the EHD fluid from the cooling wall portions 12 b to 12 e and flowing it out to the downstream connection channel 112 by communicating with the downstream connection channel 112.

  The cross-sectional shapes of the flow paths 121 and 122 need not be square, but are, for example, square. Further, if the cross-sectional shape is, for example, a square, the height (length in the vertical direction in FIG. 2) is 0.05 to 10 mm as in the flow paths 111 and 112, and the width of the square in the cross-section (the length in the horizontal direction in FIG. 3). ) Can be 0.05 to 10 mm as in the case of the channels 111 and 112. That is, the flow paths 121 and 122 have the same thickness as the flow paths 111 and 112.

  In addition, the ascending heat dissipating base channel 131 and the descending heat dissipating base channel 132 are formed in the heat dissipating base 13a by cutting, wet etching, plating, or the like as described above. The upstream heat radiating base channel 131 is a channel through which the EHD fluid is introduced from the above-described heat radiating wall portions 13 b to 13 d and flows out to the upstream connection channel 111 by communicating with the upstream connection channel 111. The downstream heat radiating base channel 132 is a channel through which the EHD fluid is introduced from the downstream connection channel 112 and flows out into the above-described heat radiation walls 13b to 13d by communicating with the downstream connection channel 112.

  The cross-sectional shapes of the flow paths 131 and 132 need not be square, but are, for example, square. If the cross-sectional shape is, for example, a quadrangle, the height (length in the vertical direction in FIG. 2) is 0.05 to 10 mm as in the flow paths 111 and 112, and the width of the cross-sectional square (the length in the horizontal direction in FIG. 3). Is 0.05 to 10 mm as in the case of the channels 111 and 112. That is, the flow paths 131 and 132 have the same thickness as the flow paths 111 and 112.

  Next, the internal structure of each of the cooling wall portions 12b to 12e will be described. Hereinafter, the cooling wall portion 12e will be described as an example, but the internal structure of the other cooling wall portions 12b to 12d is the same as that of the cooling wall portion 12e.

  4 is a sectional view taken along the line IV-IV in FIG. 2 (that is, a sectional view of the cooling wall portion 12e), and FIG. 5 is a sectional view taken along the line VV in FIG. As shown in these drawings, in the cooling wall portion 12e, ascending cooling stem channel 123, descending cooling stem channel 124, and a plurality of cooling branch channels 125a to 125g are cut, wet-etched as described above. It is formed by plating or the like.

  The ascending cooling main channel 123 is a channel for allowing the EHD fluid to flow from the ascending cooling base channel 121 by communicating with the ascending cooling base channel 121 of the cooling base 12 a. The down cooling main channel 124 is a channel for allowing the EHD fluid to flow out to the down cooling base channel 122 by communicating with the down cooling base channel 122 of the cooling base 12a.

  The cooling branch channels 125a to 125g are channels extending from the upstream cooling trunk channel 123 to the downstream cooling trunk channel 124 at equal intervals and in parallel with each other, and are communicated with the upstream cooling trunk channel 123 and the downstream cooling trunk channel 124. An EHD fluid is introduced from the upstream cooling main channel 123 and flows out to the downstream cooling main channel 124.

  The cross-sectional shape of the flow paths 123 and 124 may be a square, for example. As the size of the channels 123 and 124, if the cross section is a quadrangle, the height (length in the left-right direction in FIG. 2) is 0.05 to 10 mm as in the channels 111 and 112, and if the cross section is a quadrangle, The width (the length in the left-right direction in FIG. 4) is 0.05 to 10 mm, similar to the flow paths 111 and 112. That is, the flow paths 123 and 124 have the same thickness as the flow paths 111 and 112.

  Each of the cooling branch channels 125a to 125g may have a square cross section, for example. If the cross section is a quadrangle, the height (the length in the left-right direction in FIG. 2) is 0.05 to 10 mm, which is the same as the flow paths 123 and 124.

  In addition, if the cross-sections of the cooling branch channels 125a to 125g are square, the width (the vertical length in FIG. 4) is shorter than 1/7 of the width of the channels 123 and 124 ((0.05 to 10) / 7) Set to mm. That is, the width of each of the cooling branch channels 125a to 125g is shorter than the length obtained by dividing the width of the channels 123 and 124 by the number of the cooling branch channels 125a to 125g.

  As described above, the sum of the cross-sectional areas of the plurality of cooling branch channels 125 a to 125 g is larger than the cross-sectional area of the ascending cooling main channel 123 than the cross-sectional area of the descending cooling main channel 124 than the cross-sectional area of the ascending cooling main channel 124. Also, the cross-sectional area of the descending cooling flow path 122 is smaller than the cross-sectional area of the descending connection flow path 112 than the cross-sectional area of the ascending connection flow path 111. Therefore, the flow rate of the EHD fluid in the cooling branch channels 125a to 125g is faster than in the other channels 111, 112, 121, 122, 123, and 124. By doing so, the cooling efficiency is increased by increasing the flow rate of the EHD fluid in the cooling unit 12 and improving the heat transfer coefficient between the EHD fluid and the cooling unit in contact with the EHD fluid.

  As described above, the EHD fluid is introduced from the ascending connection channel 111 into the cooling unit 12 by communicating with the ascending connection channel 111 and the descending connection channel 112, and flows out to the descending connection channel 112. Cooling-part internal flow paths (that is, flow paths 121, 122, 123, 124, and 125a to 125g) that have a portion having a smaller cross-sectional area than the connection flow path 111 and the downstream connection flow path 112 and a high flow rate of EHD fluid. To be formed).

  Next, the internal structure of each of the heat radiating wall portions 13b to 13d will be described. Hereinafter, the heat radiating wall portion 13b will be described as an example, but the internal structure of the other heat radiating wall portions 13c and 13d is the same as that of the heat radiating wall portion 13b.

  6 is a cross-sectional view taken along the line VI-VI in FIG. 2 (that is, a cross-sectional view of the heat radiation wall 13b), and FIG. 7 is a cross-sectional view taken along the line VII-VII in FIG. As shown in these drawings, inside the heat radiating wall portion 13b, the upward heat radiating main flow path 133, the downward heat radiating main flow path 134, and the plurality of heat radiating branch flow paths 135a to 135g are cut as described above, wet etching, It is formed by plating or the like.

  The upstream heat dissipation main channel 133 is a channel for allowing the EHD fluid to flow out to the upstream heat dissipation base channel 131 by communicating with the upstream heat dissipation base channel 131 of the heat dissipation base 13a. The descending heat dissipation main channel 134 is a channel for allowing the EHD fluid to flow from the descending heat dissipation base channel 132 by communicating with the descending heat dissipation base channel 132 of the heat dissipation base 13a.

  Further, the heat radiating branch channels 135a to 135g are channels extending from the upstream heat radiating main flow channel 133 to the downstream heat radiating main flow channel 134 at equal intervals and in parallel with each other. The fluid is introduced from the downstream heat radiating main channel 134 and flows out to the upstream heat radiating main channel 133.

  The cross-sectional shape of the flow paths 133 and 134 may be a quadrangle. As for the size of the flow paths 133 and 134, if the cross section is a square, the height (the length in the left-right direction in FIG. 2) is 0.05 to 10 mm as in the flow paths 111 and 112, and the cross section is a square. The width (the length in the left-right direction in FIG. 6) is 0.05 to 10 mm, which is the same as the flow paths 111 and 112. That is, the flow paths 133 and 134 have the same thickness as the flow paths 111 and 112.

  Each of the heat radiating branch channels 135a to 135g may have a square cross-sectional shape. In addition, as the size of the heat radiating branch channels 135a to 135g, if the cross section is a quadrangle, the height (the length in the left-right direction in FIG. 2) is 0.05 to 10 mm, which is the same as the channels 133 and 134.

  Further, if the cross sections of the heat radiation branch channels 135a to 135g are square, the width (length in the vertical direction in FIG. 6) is shorter than 1/7 of the width of the channels 133 and 134 ((0.05 to 10) / 7) Set to mm. That is, the width of each of the heat radiation branch channels 135a to 135g is shorter than the length obtained by dividing the width of the flow channels 133 and 134 by the number of the heat radiation branch channels 135a to 135g.

  As described above, the sum of the cross-sectional areas of the plurality of heat radiating branch channels 135 a to 135 g is larger than the cross-sectional area of the descending heat radiating main channel 134 than the cross-sectional area of the descending heat radiating main channel 133. Also, the cross-sectional area of the descending heat radiation base channel 132 is smaller than the cross-sectional area of the descending connecting channel 111 than the sectional area of the ascending connecting channel 111. Therefore, the flow rate of the EHD fluid in the heat radiating branch channels 135a to 135g is faster than in the other channels 111, 112, 131, 132, 133, and 134. By doing in this way, the heat dissipation efficiency is raised by raising the flow rate of the EHD fluid in the heat radiating part 13 and improving the heat transfer coefficient between the EHD fluid and the heat radiating part in contact with the EHD fluid.

  As described above, the EHD fluid is introduced from the downstream connection flow path 112 and flows out to the upstream connection flow path 111 by communicating with the upstream connection flow path 111 and the downstream connection flow path 112 inside the heat radiating unit 13. By making the cross-sectional area of the flow path smaller than that of the downstream connection flow path 112 than that of the connection flow path 111, the flow path in the heat radiating section having a portion where the flow rate of the EHD fluid is high (that is, flow paths 131, 132, 133, 134, 135a). To 135 g) is formed.

  As described above, the ascending connection channel 111, the ascending cooling base channel 121, the ascending cooling main channel 123, the cooling branch channels 125a to 125g, the descending cooling stem channel 124, the descending cooling base channel 122, the descending connection channel 112, the descending A heat dissipation base flow path 132, a downward heat dissipation main flow path 134, heat dissipation branch flow paths 135a to 135g, an upward heat dissipation main flow path 133, and an upward heat dissipation base flow path 131 are formed, and these flow paths are filled with EHD fluid. The EHD fluid flows in this order.

  In order to realize the flow of the EHD fluid as described above, the flow paths 111, 121, 123, 125a to 125g, 124, 122, 112, 132, 134 are used as shown in FIGS. , 135a to 135g, 133, 131 are provided with pumps 20 that cause the EHD fluid to flow as described above by applying a voltage to the EHD fluid. These pumps 20 are also components of the cooling device 1. 3, 4, and 6, the pump 20 is indicated by a black dot in the flow path, and only a part of the pump 20 is denoted by reference numeral 20 for convenience.

  Here, the number of pumps 20 per unit volume in the flow path in each of the connecting portion 11, the cooling portion 12, and the heat radiating portion 13 will be described. At the time of designing the connecting part 11, the cooling part 12, and the heat radiating part 13, the total volume X of the cooling part internal channels 121, 122, 123, 124, 125 a to 125 g, the volume Y 1 of the upstream connecting channel 111, and the downstream connecting channel The volume Y2 of 112 and the total volume Z of the heat-radiating-port channels 131, 132, 133, 134, and 135a to 135g are known.

Therefore, the number A of the pumps 20 arranged in the cooling-portion flow paths 121, 122, 123, 124, 125 a to 125 g, the number B1 of the pumps 20 arranged in the ascending connection channel 111, and arranged in the descending connection channel 112. The number B2 of the pumps 20 to be performed and the number C of the pumps 20 disposed in the heat radiation unit flow paths 131, 132, 133, 134, 135a to 135g are set so that the following expression is satisfied.
A / X> (B1 + B2) / (Y1 + Y2)
C / Z> (B1 + B2) / (Y1 + Y2)
That is, the number of pumps 20 per unit volume in the cooling-part internal channels 121, 122, 123, 124, 125 a to 125 g is per unit volume in the ascending connection channel 111 and the descending connection channel 112 of the connection unit 11. More than the number of pumps 20 of the above. Further, the number of pumps 20 per unit volume in the heat radiating section flow paths 131, 132, 133, 134, 135 a to 135 g per unit volume in the upstream connection flow path 111 and the downstream connection flow path 112 of the connection section 11. More than the number of pumps 20 of the above. However, the number of pumps 20 per unit volume in the cooling part internal channels 121, 122, 123, 124, 125 a to 125 g and the heat radiating unit internal channels 131, 132, 133, 134, 135 a to 135 g is, for example, 1 The number of pumps 20 per unit volume in the upstream connecting channel 111 and the downstream connecting channel 112 is 0 per cubic millimeter or more.

  In the example of FIG. 3, two pumps 20 are arranged in the connecting portion 11, one in the ascending connection channel 111 and one in the descending connection channel 112. 3 and 4, in the cooling unit 12, four in the ascending cooling base channel 121, four in the descending cooling base channel 122, six in the ascending cooling main channel 123, Six pumps 20 are arranged, six in the downstream cooling main flow path 124 and six in the cooling branch flow paths 125a to 125g, 6 × 7 = 42. In the example shown in FIGS. 3 and 6, in the heat radiating portion 13, four in the upstream heat radiating base channel 131, four in the downstream heat radiating base channel 132, and six in the upstream heat radiating main channel 133. In addition, six pumps 20 are arranged in the descending heat radiating main flow path 134, and six in the heat radiating branch flow paths 135a to 135g, that is, 6 × 7 = 42.

  The number of pumps described above is an example, and is not necessarily such a number of pumps. The number of pumps per unit volume installed in the flow path of the cooling unit and the flow path of the radiator is respectively What is necessary is just to have more than the number of pumps per unit volume installed in the flow path of a connection part.

  Hereinafter, the structure of each pump 20 will be described with reference to FIGS. FIG. 8 is an enlarged view of one pump 20 in FIG. 3, FIG. 4, or FIG. 9 is a cross-sectional view taken along the line IX-IX in FIG. 8, and FIG. 10 is a cross-sectional view taken along the line XX in FIG.

  As shown in these drawings, each of the plurality of pumps 20 has one pointed electrode 21 and one slit electrode 22. The metal pointed electrode 21 and the metal slit electrode 22 are fixed to the inner wall of the flow path apart from each other. At this time, an insulator (not shown) such as a phenol resin is interposed between the inner wall of the flow path and the pump 20, so that the pump 20 and the connecting portion 11, the cooling portion 12, and the heat radiating portion 13 are not electrically connected. It is like that. The fixing between the inner wall of the flow path, the insulator, and the pump 20 is realized using, for example, an adhesive.

  As shown in FIGS. 8 and 10, the pointed electrode 21 is disposed on the upstream side of the EHD fluid flow, and the slit electrode 22 is disposed on the downstream side of the flow.

  The pointed electrode 21 has a shape that tapers toward a portion where the notch of the slit electrode 22 is formed, so that an electric field is concentrated on the tapered tip. More specifically, as shown in FIGS. 8 to 10, the pointed electrode 21 has a wedge shape in which four surfaces (two parallel surfaces and two oblique surfaces) extend from the linear tip. ing. As another example, the pointed electrode 21 may have a conical shape formed from a group of straight lines having a point as a tip and extending radially therefrom.

  The slit electrode 22 has a slit shape with a part cut away. As another example, the slit electrode 22 may be an annular electrode. Since the slit electrode 22 has a slit shape, the flow path at the position where the pump 20 is disposed is further narrowed, and the flow rate of the EHD fluid in that portion is further increased.

Although not shown, in the vicinity of each pump 20 in the connecting portion 11, the cooling portion 12, and the heat radiating portion 13 (hereinafter collectively referred to as the casings 11 to 13), the inside and outside of the casings 11 to 13 communicate with each other. Two conductive holes are formed, and conductive electrodes covered with an insulator such as phenol resin are closely inserted into the holes, and the power supply 7 is connected to the conductive electrodes and the conductive wires 7a and 7b. Is supplied to the pointed electrode 21 and the slit electrode 22. As an example, the case where the pointed electrode 21 is a negative electrode and the slit electrode 22 is a positive electrode is illustrated. (Depending on the EHD used, there is no problem even if the positive and negative electrodes are reversed)
For example, when a voltage is applied to the EHD fluid when the pointed electrode 21 becomes the negative electrode and the slit electrode 22 becomes the positive electrode, the EHD fluid is accelerated in the direction from the pointed electrode 21 to the slit electrode 22 by the EHD effect. As a result, the EHD fluid flows in the flow path, and the upstream connection flow path 111, the upstream cooling base path 121, the upstream cooling main path 123, the cooling branch paths 125a to 125g, the downstream cooling main path 124, and the downstream Cooling base channel 122, descending connection channel 112, descending heat dissipation base channel 132, descending heat dissipation main channel 134, heat dissipation branch channels 135 a to 135 g, ascending heat dissipation main channel 133, ascending heat dissipation base channel 131, ascending connection channel 111 It circulates through the path.

  As described above, in the cooling device 1, the downstream connection flow path is lower than the upstream connection flow path 111 in the flow path in the cooling section (that is, the flow paths 121, 122, 123, 124, 125 a to 125 g in the cooling section 12). By having a portion (cooling branch passages 125a to 125g) that is thinner than 112 and has a high EHD fluid flow rate, the flow rate of the EHD fluid in the cooling unit 12 is increased, and the heat between the EHD fluid and the cooling unit in contact with the EHD fluid is increased. Improves transmission rate and increases cooling efficiency.

  In such a situation, among the plurality of pumps 20, the number of pumps 20 per unit volume (or unit length along the flow of the EHD fluid) in the flow paths 121, 122, 123, 124, 125a to 125g in the cooling unit. The number of pumps 20 per unit) is the number of pumps 20 per unit volume in the upstream connecting channel 111 and the downstream connecting channel 112 of the connecting part 11 (or per unit length along the EHD fluid flow). By increasing the number of pumps 20), the flow rate can be increased, and the heat transfer coefficient between the EHD fluid and the portion where the EHD fluid is in contact can be improved. As a result, the cooling efficiency of the heating elements 2 to 4 can be increased as compared with the conventional case.

  Similarly, in the flow path in the heat radiating section (that is, in the flow paths 131, 132, 133, 134, 135 a to 135 g in the heat radiating section 13), it is narrower than the upstream connection flow path 111 and smaller than the downstream connection flow path 112. By having a portion with a fast fluid flow rate (heat radiation branch channels 135a to 135g), the flow rate of the EHD fluid in the cooling unit 12 is increased, and the heat transfer coefficient between the EHD fluid and the heat radiation unit in contact with the EHD fluid is improved, Increases heat dissipation efficiency.

  In such a situation, among the plurality of pumps 20, the pump 20 per unit volume (or per unit length along the flow of the EHD fluid) in the heat radiating section flow paths 131, 132, 133, 134, 135 a to 135 g. The number of pumps 20) is equal to the number of pumps 20 per unit volume in the upstream connecting flow path 111 and the downstream connecting flow path 112 of the connecting portion 11 (or the pump per unit length along the flow of the EHD fluid). 20), the heat dissipation efficiency in the heat dissipating section 13 is increased, which increases the flow rate and improves the heat transfer coefficient between the EHD fluid and the part in contact with the EHD fluid. The cooling efficiency of ˜4 can be increased as compared with the conventional case.

Further, in each of the plurality of pumps 20, the slit electrode 22 constituting the pump 20 further narrows the flow path at the position of the pump 20, thereby increasing the flow rate of the flow path and Since the pump 20 is driven by applying a voltage to the EHD fluid at the raised position, the flow rate is further increased to improve the heat transfer coefficient between the EHD fluid and the portion where the EHD fluid is in contact. As a result, higher cooling efficiency of the heating elements 2 to 4 can be realized.
(Second Embodiment)
Next, a second embodiment of the present invention will be described with a focus on differences from the first embodiment. The cooling device 1 of the present embodiment is different from the first embodiment only in the configuration of the pipelines in the cooling wall portions 12b to 12e.

  FIG. 11 shows the configuration of the pipeline in the cooling wall portion 12e of the present embodiment in the same format as that in FIG. 4 (that is, the format of the IV-IV sectional view in FIG. 2). The configuration of the pipe lines in the other cooling wall portions 12b to 12d is the same as that of the cooling wall portion 12e.

  As shown in FIG. 11, inside the cooling wall portion 12e of the present embodiment, one meandering cooling wall portion inner pipe 126 is formed by cutting, wet etching, plating, or the like.

  The cooling wall inner pipe 126 communicates with the upstream cooling base channel 121 at one end, extends so as to meander in the cooling wall 12e, and communicates with the downstream cooling base channel 122 at the other end. In this way, the cooling wall inner pipe 126 can flow the EHD fluid from the ascending cooling base channel 121 to the descending cooling base channel 122.

  The cross-sectional shape of the cooling wall portion inner pipe 126 may be, for example, a quadrangle. Further, as the size of the cooling wall inner pipe 126, for example, if the cross section is a square, its height (length in the left-right direction in FIG.

  Further, if the cross section of the cooling branch flow paths 125a to 125g is a quadrangle, the width (in the plane in FIG. 11 and the direction perpendicular to the flow of the EHD fluid) is shorter than the width of the flow paths 121 and 122 (for example, 1 mm). .

  As described above, the cross-sectional area (thickness) of the plurality of cooling wall inner pipe lines 126 is larger than the cross-sectional area of the ascending cooling base channel 121 than the cross-sectional area of the descending cooling base channel 122. It is smaller than the cross-sectional area of the downstream connecting flow path 112 than the area. Therefore, the flow rate of the EHD fluid in the cooling wall inner pipe 126 is faster than in the other flow paths 111, 112, 121, 122. By doing so, the flow rate of the EHD fluid in the cooling unit 12 is increased, the heat transfer coefficient between the EHD fluid and the cooling unit in contact with the EHD fluid is improved, and the cooling efficiency is increased.

  As described above, the EHD fluid is introduced from the ascending connection channel 111 into the cooling unit 12 by communicating with the ascending connection channel 111 and the descending connection channel 112, and flows out to the descending connection channel 112. A cooling-part internal flow path (that is, a flow path composed of flow paths 121, 122, and 126) having a portion that is narrower than the connection flow path 111 and smaller than the downstream connection flow path 112 and has a high EHD fluid flow rate is formed.

  As shown in FIG. 11, the same pump 20 as in the first embodiment is also provided at each of a plurality of positions inside the cooling wall inner pipe 126 (positions of black spots in the cooling wall inner pipe 126). The mounting method is the same as that in the first embodiment, and when a voltage is applied to these pumps 20, the EHD from the upstream connection flow path 111 side to the downstream connection flow path 112 side in the cooling wall inner conduit 126. The fluid flows.

Here too, at the time of designing the cooling unit 12, the total volume X ′ of the cooling-unit flow paths 121, 122, and 126 is known. Therefore, the number A ′ of the pumps 20 disposed in the cooling-portion flow paths 121, 122, 126, the number B 1 of the pumps 20 disposed in the upstream connection flow path 111, and the number of the pumps 20 disposed in the downstream connection flow path 112. B2 is set so that the following equation is satisfied.
A ′ / X> (B1 + B2) / (Y1 + Y2)
That is, the number of pumps 20 per unit volume in the cooling unit internal channels 121, 122, 126 is greater than the number of pumps 20 per unit volume in the upstream connection channel 111 and the downstream connection channel 112 of the connection unit 11. To do more. However, the number of pumps 20 per unit volume in the cooling unit internal channels 121, 122, 126 is, for example, 1 unit / cubic millimeter or more, and the units in the ascending connection channel 111 and the descending connection channel 112. The number of pumps 20 per volume is 0/1 cubic millimeter or more.

  In the example of FIGS. 3 and 11, in the cooling unit 12, four in the ascending cooling base channel 121, four in the descending cooling base channel 122, and 24 in the cooling wall inner pipe 126 total 32. That is, the pump 20 is arranged.

  Thus, similarly to the first embodiment, in the cooling device 1, in the cooling unit flow path (that is, the flow paths 121, 122, and 126 in the cooling unit 12), the downstream connection flow is lower than the upstream connection flow path 111. By having a part (cooling wall inner pipe 126) that is narrower than the path 112 and has a high EHD fluid flow rate, the flow rate of the EHD fluid in the cooling unit 12 is increased, and between the EHD fluid and the cooling unit that the EHD fluid is in contact with. The heat transfer rate is improved and the cooling efficiency is increased.

  In such a situation, among the plurality of pumps 20, the number of pumps 20 per unit volume (or the number of pumps 20 per unit length along the flow of the EHD fluid) in the cooling unit flow paths 121, 122, and 126. The number of pumps 20 per unit volume in the upstream connecting flow path 111 and the downstream connecting flow path 112 of the connecting portion 11 (or the number of pumps 20 per unit length along the flow of the EHD fluid). By increasing the flow rate, the flow rate can be increased, and the heat transfer rate between the EHD fluid and the portion where the EHD fluid is in contact can be improved. As a result, the cooling efficiency of the heating elements 2 to 4 can be increased as compared with the conventional case.

Similarly, in each of the plurality of pumps 20, the slit electrode 22 constituting the pump 20 further narrows the flow path at the position of the pump 20, thereby increasing the flow rate of the flow path, Since the pump 20 is driven by applying a voltage to the EHD fluid at a position where the flow velocity is increased, the flow velocity is further increased to improve the heat transfer rate between the EHD fluid and the portion where the EHD fluid is in contact. As a result, higher cooling efficiency of the heating elements 2 to 4 can be realized.
(Third embodiment)
Next, a second embodiment of the present invention will be described with a focus on differences from the first embodiment. The cooling device 1 of the present embodiment is different from the first embodiment only in the configuration of the pipelines in the cooling wall portions 12b to 12e.

  FIG. 12 shows the configuration of the pipeline in the cooling wall portion 12e of the present embodiment in the same format as that in FIG. 4 (that is, the format of the IV-IV sectional view in FIG. 2). XIII-XIII sectional drawing is shown, and the enlarged view of the part enclosed with the dashed-two dotted line 40 of FIG. 12 is shown in FIG. The configuration of the pipe lines in the other cooling wall portions 12b to 12d is the same as that of the cooling wall portion 12e.

  As shown in these drawings, a tank inflow conduit 127, a tank outflow conduit 128, and a tank 129 are provided inside the plurality of cooling walls 12e of the present embodiment, such as cutting, wet etching, and plating. Is formed by.

  The tank inflow conduit 127 is a channel for allowing the EHD fluid to flow from the upstream cooling base channel 121 by communicating with the upstream cooling base channel 121 of the cooling base 12a. The tank outflow pipe 128 is a flow path for allowing the EHD fluid to flow out to the down cooling base flow path 122 by communicating with the down cooling base flow path 122 of the cooling base 12a.

  The cross-sectional shape of the flow paths 127 and 128 may be a quadrangle. As the size of the channels 127 and 128, for example, if the cross section is a square, the height (the length in the left-right direction in FIG. 2) is 0.05 to 10 mm as in the channels 121 and 122, and the cross section is a square. Then, the width (the length in the left-right direction in FIG. 6) is set to 0.05 to 10 mm as in the flow paths 121 and 122. That is, the flow paths 127 and 128 have the same thickness as the flow paths 121 and 122.

  The tank 129 is partly formed in a disk shape, and communicates with the tank inflow channel 127 and the tank outflow channel 128, whereby the EHD fluid is introduced from the tank inflow channel 127 and the descending tank outflow channel It is designed to flow out to 128.

  The tank 129 is much larger in volume than the tank inflow conduit 127 and the tank outflow conduit 128, and occupies most of the cooling wall portion 12e. Further, a part of the tank 129 is in the cooling base portion 12a. It extends to. In this way, a large amount of EHD fluid can be temporarily stored in the tank 129. For example, as the size of the tank 129, the thickness (length in the left-right direction in FIG. 2) is 0.05 to 10 mm, which is the same as the flow paths 127 and 128, and the volume is 30% or more of the external volume of the cooling wall portion 12e. .

  As described above, inside the cooling unit 12, the EHD fluid is introduced from the upstream connection channel 111 and flows out to the downstream connection channel 112 by communicating with the upstream connection channel 111 and the downstream connection channel 112. A flow path 121, 122, 127, 128 and a disk-shaped tank 129 that communicates with the flow path 121, 122, 127, 128 in the cooling section and temporarily stores the EHD fluid are formed.

  In addition, the same pump 20 as that in the first embodiment is arranged at a plurality of locations in the tank 129 (positions of black spots in the cooling wall portion inner pipe 126) by the same mounting method as in the first embodiment. By applying a voltage to these pumps 20, the EHD fluid flows in the cooling wall inner pipe 126.

  Specifically, as shown in FIGS. 12 and 14, the pumps 20 are arranged at equal intervals at four positions on the periphery of the tank 129, and the EHD fluid is driven in the clockwise direction in FIG. Thus, the pointed electrode 21 and the slit electrode 22 of the pump 20 are arranged.

  By arranging the pump 20 in this manner, the EHD fluid to which a voltage is applied by the pump 20 in the tank 129 circulates clockwise in the tank 129 as indicated by an arrow, and a part of the tank outflow pipe line. The EHD fluid flows out from 128 to the downstream cooling base channel 122, and accordingly, the EHD fluid flows in through the upstream cooling base channel 121 and the tank inflow conduit 127.

  By this circulation, the main flow of the EHD fluid circulating through the cooling unit 12, the coupling unit 11, and the heat radiation unit 13 (tank outflow pipe 128, down cooling base channel 122, down coupling channel 112, down heat radiation base channel 132, down In addition to the heat dissipation main flow path 134, the heat dissipation branch flow paths 135a to 135g, the upward heat dissipation main flow path 133, the upward heat dissipation base flow path 131, the upward connection flow path 111, the upward cooling base flow path 121, and the flow of the tank inflow conduit 127) The flow rate of the EHD fluid in the tank 129 can be increased.

  Further, in the tank 129, a plurality of plate-like heat radiation fins 30 and 31 for increasing the contact area between the EHD fluid and the cooling unit 12 are integrated with the cooling unit 12 along the flow of the EHD fluid. Is formed. The cooling effect of the heat generating elements 2 to 4 is further enhanced by the radiation fins 30 and 31.

  As described above, the tank 129 for temporarily storing the EHD fluid is formed in the cooling unit 12, and the pump 20 is arranged so that the EHD fluid circulates in the cooling unit 12. A flow different from the flow (main flow) of the EHD fluid circulating in the part 11 and the heat radiating unit 13 can be generated in the cooling unit 12, whereby the flow rate of the EHD fluid in the cooling unit 12 is independent of the main flow. As a result, it is possible to achieve cooling of the heating elements 2 to 4 with higher efficiency than conventional.

(Other embodiments)
As mentioned above, although embodiment of this invention was described, the scope of the present invention is not limited only to the said embodiment, The various form which can implement | achieve the function of each invention specific matter of this invention is included. It is.

  For example, in each of the embodiments described above, the structure of the flow paths in the heat radiating wall portions 13b to 13d is as shown in FIGS. 4 and 5, but the structure of the heat radiating wall portions 13b to 13d is the same as that in FIG. May be. Specifically, in FIG. 11, the cooling wall portion 12e is replaced with each of the heat radiating wall portions 13b to 13d, the cooling base portion 12a is replaced with the heat radiating base portion 13a, and the ascending cooling base channel 121 is replaced with the descending heat radiating base channel 132. The downstream cooling base channel 122 may be replaced with the upstream heat dissipation base channel 131.

  Moreover, you may make the structure of the thermal radiation wall part 13b-13d the same thing as FIGS. Specifically, in FIG. 12, the cooling wall portion 12e is replaced with each of the heat radiating wall portions 13b to 13d, the cooling base portion 12a is replaced with the heat radiating base portion 13a, and the ascending cooling base channel 121 is replaced with the descending heat radiating base channel 132. The downstream cooling base channel 122 may be replaced with the upstream heat dissipation base channel 131.

  Further, the pointed electrode 21 and the slit electrode 22 of each pump 20 may not be the shape as in the above embodiment, but may be a planar conductor pattern affixed to the inner wall of the flow path (via an insulator). .

  Moreover, the inverter provided with the switching element to be cooled by the cooling device 1 is not limited to a hybrid vehicle, and may be used for driving a motor such as a train (bullet train, train, etc.), an elevator, and the like.

  The cooling target of the cooling device 1 is not limited to the switching element, and any heating element that generates heat at a temperature higher than the surrounding environmental temperature may be used, for example, a CPU.

DESCRIPTION OF SYMBOLS 1 Cooling device 2-4 Heat generating body 11 Connecting part 12 Cooling part 12a Cooling base part 12b-12e Cooling wall part 13 Radiating part 13a Radiating base part 13b-13d Radiating wall part 20 Pump 21 Pointed electrode 22 Slit electrode 30, 31 Radiating fin 111 112, 122 Connection flow path 121, 122 Cooling base flow path 123, 124 Cooling main flow path 125a-125g Cooling branch flow path 126 Cooling wall inner pipe 127 Tank inflow pipe 128 Tank outflow pipe 129 Tank 131, 132 Radiation base flow path 133 , 134 Radiation trunk channel 135a-135g Radiation branch channel

Claims (5)

A cooling device for cooling a heating element (2-4) using an EHD fluid flowing by an electrohydrodynamic (EHD for short) effect,
A cooling unit (12) facing the heating element (2-4) and receiving heat generated by the heating element (2-4) by heat conduction;
A heat dissipating part (13) for releasing heat to the outside of the cooling device;
A connection part (11) connected to the cooling part (12) and the heat dissipation part (13), for transporting heat from the cooling part (12) to the heat dissipation part (13),
Inside the connecting part (11), an upstream connecting flow path (111) for allowing EHD fluid to flow from inside the heat dissipating part (13) into the cooling part (12), and EHD fluid flowing into the cooling part (12) ) And a downstream connecting flow path (112) for flowing into the heat radiating portion (13) from inside,
In the cooling part (12), the EHD fluid is communicated from the upstream connection channel (111) to the downstream connection channel by communicating with the upstream connection channel (111) and the downstream connection channel (112). (112), and the flow path in the cooling section (121, 122, 123, 124, which has a portion that is narrower than the downstream connection flow path (112) and faster in flow rate of the EHD fluid than the upstream connection flow path (111). 125a-125g, 126) are formed,
Inside the heat radiating part (13), the EHD fluid is communicated from the down connecting channel (112) to the up connecting channel by communicating with the up connecting channel (111) and the down connecting channel (112). (111) is formed in the heat dissipating section flow channel (131, 132, 133, 134, 135a-135g),
The upstream connection channel (111), the cooling unit internal channel (121, 122, 123, 124, 125a to 125g, 126), the downward connection channel (112), and the heat dissipation unit internal channel (131, 132, 133). , 134, 135a to 135g), a pump (20) for causing the EHD fluid to flow by applying a voltage to the EHD fluid is disposed at each of a plurality of positions inside the flow path.
Among the plurality of pumps (20), the number of pumps (20) per unit volume in the flow passages in the cooling section (121, 122, 123, 124, 125a to 125g, 126) is the connection section (11). The number of pumps (20) per unit volume in the ascending connection channel (111) and the descending connection channel (112) is larger than the number of pumps (20). A cooling device for cooling a heating element (2-4) using an EHD fluid flowing by an electrohydrodynamic (EHD for short) effect,
A cooling unit (12) facing the heating element (2-4) and receiving heat generated by the heating element (2-4) by heat conduction;
A heat dissipating part (13) for releasing heat to the outside of the cooling device;
A connection part (11) connected to the cooling part (12) and the heat dissipation part (13), for transporting heat from the cooling part (12) to the heat dissipation part (13),
Inside the connecting part (11), an upstream connecting flow path (111) for allowing EHD fluid to flow from inside the heat dissipating part (13) into the cooling part (12), and EHD fluid flowing into the cooling part (12) ) And a downstream connecting flow path (112) for flowing into the heat radiating portion (13) from inside,
In the cooling part (12), the EHD fluid is communicated from the upstream connection channel (111) to the downstream connection channel by communicating with the upstream connection channel (111) and the downstream connection channel (112). (112), the flow path in the cooling part (121, 122, 123, 124, 125a to 125g, 126) is formed,
Inside the heat radiating part (13), the EHD fluid is communicated from the down connecting channel (112) to the up connecting channel by communicating with the up connecting channel (111) and the down connecting channel (112). (111), and the flow path in the heat radiating section (131, 132, 133, 134, which has a portion that is narrower than the downstream connection flow path (112) and faster in flow rate of the EHD fluid than the upstream connection flow path (111). 135a-135g) are formed,
The upstream connection channel (111), the cooling unit internal channel (121, 122, 123, 124, 125a to 125g, 126), the downward connection channel (112), and the heat dissipation unit internal channel (131, 132, 133). , 134, 135a to 135g), a pump (20) for causing the EHD fluid to flow by applying a voltage to the EHD fluid is disposed at each of a plurality of positions inside the flow path.
Among the plurality of pumps (20), the number of pumps (20) per unit volume in the flow passages (131, 132, 133, 134, 135a to 135g) in the heat radiating portion is the number of the pumps (20) in the connecting portion (11). The cooling device, wherein the number of pumps (20) per unit volume in the upstream connecting channel (111) and the downstream connecting channel (112) is larger.   Each of the plurality of pumps (20) has a pointed electrode (21) and a slit electrode (22), and the pointed electrode (21) is tapered toward the slit electrode (22). The slit electrode (22) has a slit shape so that the flow path at the position of the pump (20) is further narrowed. Cooling system. A cooling device for cooling a heating element (2-4) using an EHD fluid flowing by an electrohydrodynamic (EHD for short) effect,
A cooling unit (12) facing the heating element (2-4) and receiving heat generated by the heating element (2-4) by heat conduction;
A heat dissipating part (13) for releasing heat to the outside of the cooling device;
A connection part (11) connected to the cooling part (12) and the heat dissipation part (13), for transporting heat from the cooling part (12) to the heat dissipation part (13),
Inside the connecting part (11), an upstream connecting flow path (111) for allowing EHD fluid to flow from inside the heat dissipating part (13) into the cooling part (12), and EHD fluid flowing into the cooling part (12) ) And a downstream connecting flow path (112) for flowing into the heat radiating portion (13) from inside,
In the cooling part (12), the EHD fluid is communicated from the upstream connection channel (111) to the downstream connection channel by communicating with the upstream connection channel (111) and the downstream connection channel (112). (112) The flow path (121, 122, 127, 128) in the cooling section for flowing to the tank and the flow path (121, 122, 127, 128) in the cooling section, and a tank for temporarily storing the EHD fluid ( 129), and
Inside the heat radiating part (13), the EHD fluid is communicated from the down connecting channel (112) to the up connecting channel by communicating with the up connecting channel (111) and the down connecting channel (112). (111) is formed in the heat dissipating section flow channel (131, 132, 133, 134, 135a-135g),
The upstream connection flow path (111), the cooling part internal flow path (121, 122, 127, 128), the downward connection flow path (112), and the heat dissipation part internal flow path (131, 132, 133, 134, 135a to 135g). ), A pump (20) for causing the EHD fluid to flow by applying a voltage to the EHD fluid is disposed at each of a plurality of positions inside the flow path.
A plurality of pumps (20) are also disposed in the tank (129), and the plurality of pumps (20) in the tank (129) circulate EHD fluid in the tank (129). The cooling device characterized by being arranged in. A cooling device for cooling a heating element (2-4) using an EHD fluid flowing by an electrohydrodynamic (EHD for short) effect,
A cooling unit (12) facing the heating element (2-4) and receiving heat generated by the heating element (2-4) by heat conduction;
A heat dissipating part (13) for releasing heat to the outside of the cooling device;
A connection part (11) connected to the cooling part (12) and the heat dissipation part (13), for transporting heat from the cooling part (12) to the heat dissipation part (13),
Inside the connecting part (11), an upstream connecting flow path (111) for allowing EHD fluid to flow from inside the heat dissipating part (13) into the cooling part (12), and EHD fluid flowing into the cooling part (12) ) And a downstream connecting flow path (112) for flowing into the heat radiating portion (13) from inside,
In the cooling part (12), the EHD fluid is communicated from the upstream connection channel (111) to the downstream connection channel by communicating with the upstream connection channel (111) and the downstream connection channel (112). (112) are formed in the cooling section flow passages (121, 122, 123, 124, 125a to 125g, 126),
Inside the heat radiating part (13), the EHD fluid is communicated from the down connecting channel (112) to the up connecting channel by communicating with the up connecting channel (111) and the down connecting channel (112). (111) A flow path (131, 132, 127, 128) in the heat radiating section and a tank (T, 131, 132, 127, 128) communicating with the heat radiating section internal flow path (131, 132, 127, 128) for temporarily storing EHD fluid ( 129), and
The ascending connection channel (111), the cooling unit internal channel (121, 122, 123, 124, 125a to 125g, 126), the down connection channel (112), and the heat dissipation unit internal channel (131, 132, 127). 128), a pump (20) for causing the EHD fluid to flow by applying a voltage to the EHD fluid is disposed at each of a plurality of positions inside the flow path consisting of 128).
A plurality of pumps (20) are also disposed in the tank (129), and the plurality of pumps (20) in the tank (129) circulate EHD fluid in the tank (129). The cooling device characterized by being arranged in.

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