JP2013120010A - Cooling device, electronic device equipped with the same, and electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device for efficiently circulating a refrigerant and enhancing cooling performance.SOLUTION: The cooling device 3 is composed of a heat receiving part 4 equipped with a heat receiving plate 11 for transferring heat to a working fluid 12, a radiation part 5 for radiating the heat of the working fluid 12, a radiating path 6, and a return path 7 in which both the paths are used to connect the heat receiving part 4 to the radiation part 5 and the working fluid 12 is circulated to the heat receiving part 4, the radiating path 6, the radiation part 5, the return path 7, and the heat receiving part 4 so as to transfer the heat. In the vicinity of the heat receiving part 4 of the return path 7 or in the heat receiving part 4, a check valve 18 for controlling a flow of the working fluid 12 is arranged and in a box composed of a valve cover 24 with an inlet and a valve holder 27 with a concave part 25 and an introducing port 26, the check valve 18 is equipped with a first valve element 21 moving in the concave part 25 of the valve holder 27 and a pressure balancing means arranged in the box to balance pressures in the front and rear of the check valve 18.

Description

  The present invention relates to a cooling device, an electronic device equipped with the cooling device, and an electric vehicle.

  Conventionally, this type of cooling device is known to be mounted on a power conversion circuit of an electric vehicle. In an electric vehicle, an electric motor serving as a driving power source is switched by an inverter circuit that is a power conversion circuit. A plurality of semiconductor switching elements represented by power transistors are used in the inverter circuit, and a large current of several tens of amperes flows through each element. For this reason, the semiconductor switching element generates a large amount of heat even with a small loss and needs to be cooled.

  Therefore, conventionally, as in Patent Document 1, for example, a boil cooling device having a refrigerant radiator and a refrigerant tank at the top and bottom has cooled an inverter circuit arranged at the bottom.

JP-A-8-126125

  In such a conventional cooling device, the refrigerant tank is disposed in contact with the semiconductor switching element, and the liquefied refrigerant in the refrigerant tank is vaporized by taking heat from the switching element.

  And the cycle which raises the vaporized refrigerant | coolant to the refrigerant | coolant heat radiator arrange | positioned at the upper part, cools, liquefies, and is dripped again at the lower part is repeated. In other words, the refrigerant circulates by natural convection.

  However, in such a natural convection type, simple convection heat transfer can be used for the liquefied refrigerant stored in the refrigerant tank through the wall (heat transfer surface) of the refrigerant tank. Therefore, the heat transfer rate on the heat transfer surface could not be increased, and as a result, the cooling effect of the switching elements and the like could not be increased.

  Then, this invention aims at improving a cooling effect by raising the heat transfer rate in a heat-transfer surface.

  In order to achieve this object, the present invention provides a heat receiving portion including a heat receiving plate that transfers heat from the heating element to the working fluid, a heat radiating portion that releases the heat of the working fluid, the heat receiving portion, and the heat receiving portion. A heat dissipation path connecting the heat dissipation part and a return path are configured, and the working fluid is circulated to the heat receiving part, the heat dissipation path, the heat dissipation part, the return path, and the heat receiving part to transfer heat. A cooling device is provided with a check valve that controls the flow of the working fluid in the vicinity of or in the heat receiving portion of the return path, and the check valve has an inlet connected to the return path. A valve holder having an outlet connected to the heat receiving portion and forming a box by the valve cover, a first valve body movably provided in a recess of the valve holder, The pressure before and after the check valve provided in the box A pressure balance means for lance, and the pressure balance means balances the pressure before and after the check valve when the pressure in the heat receiving portion increases and when the first valve body is inoperative. It achieves the intended purpose.

  According to the present invention, a heat receiving portion including a heat receiving plate that transfers heat from the heat generating element to the working fluid, a heat radiating portion that releases the heat of the working fluid, and a heat radiating path that connects the heat receiving portion and the heat radiating portion. And a return path, and the working fluid is circulated to the heat receiving part, the heat dissipation path, the heat dissipation part, the return path, and the heat receiving part to transfer heat, and the heat receiving part of the return path A check valve for controlling the flow of the working fluid is provided in the vicinity of or in the heat receiving part, and the check valve is connected to the heat receiving part and a valve cover having an inlet connected to the return path. A valve holder having a flow outlet and forming a box with the valve cover; a first valve body movably provided in a recess of the valve holder; and a front and rear of the check valve provided in the box Pressure balancing means for balancing pressure, and Since the pressure balance means balances the pressure before and after the check valve when the pressure in the hot part rises and the first valve body is not in operation, the cooling effect can be enhanced. .

  That is, in the present invention, the circulation path of the working fluid serving as a refrigerant is a heat receiving portion, a heat radiating route, a heat radiating portion, a return route, and the heat receiving portion. An inflow pipe that supplies the working fluid into the heat receiving section is connected to the heat receiving section side of the return path, and a check valve that controls the flow of the working fluid is provided at the tip of the inflow pipe.

  The movable part of the valve body of the check valve is opened in the valve holder, and the valve body is opened by the pressure of the working fluid accumulated on the valve body, that is, the movable part of the valve body is movable in the valve holder. Therefore, the opening state is not excessive, and as a result, the working fluid is not supplied excessively into the heat receiving portion, and the supply of the working fluid can be controlled to an appropriate amount. In addition, the working fluid dropped from the introduction pipe to the heat receiving plate is vaporized immediately thereafter, and the vapor moves on the surface of the heat receiving plate as a high-speed air stream from the gap between the introduction pipe and the heat receiving plate due to rapid volume expansion accompanying boiling. Thus, the working fluid is formed as a thin film over the entire surface of the heat receiving plate around the outlet of the introduction pipe. Then, this membrane-like working fluid receives heat from the heat receiving plate and instantly heats and evaporates, whereby heat removal with a high heat transfer rate is possible, and an extremely high cooling effect can be obtained.

  Further, the working fluid in the heat receiving part is all in the liquid phase except for the vaporized part, and if left in the heat receiving part as it is, it becomes an obstacle to vaporization, so it is necessary to move it quickly from the heat receiving part. In contrast, in the present invention, rapid volume expansion due to vaporization can generate not only the gas phase component of the working fluid but also the liquid phase component remaining in the heat receiving portion at the same time to generate a driving force that can move to the heat radiating portion at high speed. As a result, it is possible to realize non-powered conveyance of the working fluid from the heat receiving unit to the condensing unit using only the heat removal energy of the object to be cooled.

  In addition, even when the first valve body is not opened due to an increase in the pressure in the heat receiving portion due to an increase in the input heat amount, excessive pressure on the introduction pipe side is caused to flow in by the second valve body which is a pressure balance means. By escaping to the pipe side and balancing the pressure before and after the check valve, the first valve body is opened, and the working fluid is supplied into the heat receiving portion, so that the working fluid can be circulated stably.

Schematic of the electric vehicle according to the first embodiment of the present invention. Schematic showing the cooling system Exploded perspective view showing the check valve Partially cut perspective view showing the check valve (A) The block diagram which shows the state which the check valve closed, (b) The block diagram which shows the state which the 1st valve body of the check valve opened, (c) The 2nd valve body of the check valve Configuration diagram showing the open state (A) The block diagram which shows the state which the check valve of Embodiment 2 of this invention closed, (b) The block diagram which shows the state which the 1st valve body of the check valve opened, (c) (a) The block diagram which shows the AA cross section of (A) The figure which shows the state of the working fluid near a micropore in a meniscus formation state, (b) The figure which shows the state of the working fluid near a micropore in a meniscus destruction state, (c) Embodiment 2 of this invention The block diagram which shows the state where the non-return valve is closed (A) The block diagram which shows the state which the check valve of Embodiment 3 of this invention closed, (b) The block diagram which shows the state which the 1st valve body of the check valve opened, (c) (a) The block diagram which shows the BB cross section of

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
As shown in FIG. 1, an electric motor (not shown) that drives an axle (not shown) of an electric vehicle 1 is connected to an inverter circuit 2 that is a power conversion device arranged in the electric vehicle 1.

  The inverter circuit 2 supplies electric power to the electric motor, and includes a plurality of semiconductor switching elements (10 in FIG. 2). The semiconductor switching elements (10 in FIG. 2) generate heat during operation.

  For this reason, in order to cool this semiconductor switching element (10 in FIG. 2), a cooling device 3 is provided. The cooling device 3 includes a heat receiving portion 4 and a heat radiating portion 5 that radiates heat absorbed by the heat receiving portion 4, and a working fluid (12 in FIG. 2) serving as a heat medium between the heat receiving portion 4 and the heat radiating portion 5. For example, by providing the heat radiation path 6 and the return path 7 for circulating water), the heat receiving section 4, the heat radiation path 6, the heat radiation section 5, the feedback path 7, and the circulation path serving as the heat receiving section 4 are configured.

  That is, in this circulation path, the working fluid (12 in FIG. 2) is a gas (water vapor in the case of water) or a liquid and a mixed state thereof, the heat receiving part 4, the heat radiation path 6, the heat radiation part 5, the return path 7, It circulates in one direction with the heat receiving part 4.

  As shown in FIG. 2, the heat radiating section 5 includes a heat radiating body 8 that releases heat to the outside air.

  The heat dissipating body 8 includes a block body (not shown) in which fins formed by thinly forming aluminum in a strip shape are stacked at a predetermined interval, and a heat dissipating path 6 penetrating the stacked fins.

  Then, heat is radiated by blowing outside air from the blower 9 to the interface of the radiator 8. The heat radiation from the interface of the radiator 8 can also be utilized for heating in the electric vehicle 1.

  Further, as shown in FIG. 2, the heat receiving portion 4 is in contact with the semiconductor switching element 10 to absorb heat and a heat receiving space that covers the interface of the heat receiving plate 11 and evaporates the flowing working fluid 12. And a heat-receiving plate cover 14 that forms 13.

  Furthermore, the heat receiving plate cover 14 is provided with an inlet 15 for flowing the liquefied working fluid 12 into the heat receiving space 13 and an outlet 16 for discharging the working fluid 12 from the heat receiving space 13 as a gas.

  That is, the inlet 15 is provided on the upper surface of the heat receiving plate cover 14, and the outlet 16 is provided on the side surface of the heat receiving plate cover 14. The return path 7 is connected to the inlet 15, and the heat dissipation path 6 is connected to the outlet 16. Connected.

  Further, on the heat receiving part 4 side of the return path 7, an introduction pipe 17 having an inflow pipe 19 for supplying the working fluid 12 into the heat receiving part 4 and a check valve 18 and connected to the check valve 18 is provided. The heat receiving space 13 is plunged.

  The operation of the cooling device 3 having such a configuration will be described.

  In the above configuration, when the semiconductor switching element 10 of the inverter circuit 2 starts to operate, electric power is supplied to the electric motor, and the electric vehicle 1 starts to move.

  At this time, when a large current flows through the semiconductor switching element 10, at least several percent of the total power is lost and a large amount of heat is generated.

  On the other hand, when the heat generated from the semiconductor switching element 10 is transferred from the semiconductor switching element 10 to the liquid working fluid 12 supplied onto the heat receiving plate 11 of the heat receiving space 13, the liquid working fluid is heated. 12 is vaporized in an instant, flows from the discharge port 16 to the heat radiation path 6, and releases heat to the outside air by the heat radiation portion 5.

  The working fluid 12 that has released heat by the action of the heat radiating unit 5 is liquefied and flows to the return path 7 and accumulates on the check valve 18 in the introduction pipe 17.

  While the liquefied working fluid 12 gradually increases in the return path 7, the vaporization amount of the working fluid 12 in the heat receiving space 13 decreases, the pressure in the heat receiving space 13 also decreases, and the pressure on the check valve 18 is increased. When the check valve 18 is pushed down by the water head pressure of the accumulated working fluid 12, it is supplied again onto the heat receiving plate 11 in the heat receiving space 13.

  In this way, the working fluid 12 circulates in the cooling device 3 to cool the semiconductor switching element 10.

  Here, the cooling mechanism in the heat receiving space 13 will be described.

  In the heat receiving space 13, the working fluid 12 from the return path 7 is dropped as droplets from the check valve 18 onto the heat receiving plate 11.

  At this time, the interface of the heat receiving plate 11 has a shape in which the flow path expands radially, and an appropriate amount of the working fluid 12 can be supplied by the action of the check valve 18 described later. Then, the supplied working fluid 12 spreads on the heat receiving plate 11 as a thin film-like refrigerant with a high-speed air flow due to volume expansion at the time of boiling as described above. Since the back surface side of the heat receiving plate 11 is in contact with the semiconductor switching element 10, the working fluid 12 that has become a thin film-like refrigerant on the heat receiving plate is instantly heated and vaporized to produce a high cooling effect. Become.

  Since the atmospheric pressure in the circulation path including the heat receiving space 13 is set lower than the atmospheric pressure, the working fluid 12 is vaporized at a temperature lower than the boiling of water in the atmospheric pressure even if water is used. Can do.

  In the present embodiment, the internal pressure is reduced to -97 KPa and the inside of the circulation path is set to a saturated vapor pressure state, so that the boiling temperature corresponding to the outside air temperature is determined and water can be easily vaporized. Sometimes the semiconductor switching element 10 can be efficiently deprived of heat and cooled.

  Further, when the working fluid 12 is vaporized, the pressure in the heat receiving space 13 increases. However, the working fluid 12 does not flow back to the return path 7 due to the action of the check valve 18, and the discharge port is surely discharged. 16 is discharged to the heat radiation path 6.

  By operating the cooling device 3 in this manner, a regular heat receiving and releasing cycle can be performed, and the working fluid 12 can be continuously vaporized in the heat receiving space 13 to cool the semiconductor switching element 10. A large cooling effect can be obtained.

  Here, the most characteristic part of the present invention will be described.

  As shown in the exploded view of FIG. 3, the check valve 18 is smaller than the first valve body 21 provided to cover the opening 20 on the upper surface of the first valve body 21 and the first valve body 21. The second valve body 22 includes a valve cover 24 having a recess 23 (FIG. 5) and an inflow port 15, and a valve holder 27 having a recess 25 and an inlet 26. The inside of the recess 25 is movable, and the second valve element 22 is configured to move within the recess 23 of the valve cover 24.

  In the present embodiment, the pressure balance means includes an opening 20 provided in the first valve body 21 and a second valve body 22 provided on the upper surface of the first valve body 21 so as to cover the opening. The opening 20 is a circular hole whose size is smaller than the inner diameter of the inflow pipe 19.

  The material of the first valve body 21 and the second valve body 22 is copper, brass, SUS, or the like.

  As shown in the assembly diagram of FIG. 4, the first valve body 21 is fixed by being sandwiched between the valve holder 27 and the valve cover 24 so that the movable portion thereof is accommodated in the concave portion 25 of the valve holder 27. 24 is fixed by screws or the like (not shown).

  As a result, the movable portion of the first valve body 21 is movable only in the recess 25 of the valve holder 27. The depth of the recess 25 is about 1 to 2 mm, and even if the check valve 18 is opened, it enters the heat receiving portion 4. The supply of the working fluid 12 can be controlled to an appropriate amount without excessively supplying the working fluid 12.

  Further, as described above, the working fluid 12 dripped onto the heat receiving plate 11 in FIG. 2 spreads on the heat receiving plate 11 as a thin film so as to diffuse the interface of the heat receiving plate 11 to the surroundings. Upon receiving heat, it is heated and vaporized instantly, the heat transfer rate on the heat transfer surface is improved, and the cooling effect can be enhanced.

  Furthermore, by the volume expansion due to the vaporization, the working fluid inside the heat receiving portion can be moved to the discharge port 16 as a high-speed flow. At this time, surplus working fluid other than the vaporized working fluid is simultaneously removed from the heat receiving plate 11. Since the working fluid film necessary for vaporization is always formed, the heat transfer coefficient on the heat transfer surface is increased as a result, and the cooling effect can be enhanced.

  Further, since the second valve body 22 is smaller than the first valve body 21, the size and depth of the recess 23 provided in the valve cover 24 is equal to or less than the recess 25 of the valve holder 27, and the second valve body 22 is movable. And what is necessary is just to be able to release the pressure in the heat receiving part 4. FIG.

  Next, the operation of the pressure balance means will be described with reference to FIG.

  FIG. 5A shows a state in which the first valve body 21 is closed when the working fluid 12 receives heat from the heat receiving plate 11 and vaporization starts and the pressure in the heat receiving space 13 increases. FIG. 5B shows that the amount of the working fluid 12 in the heat receiving portion 4 decreases with vaporization, and the pressure in the heat receiving space 13 decreases, so that the first valve body 21 is opened and the working fluid 12 is moved to the heat receiving portion. 4 is supplied to the inside. 5 (c) is a state in which the pressure balance around the check valve 18 is lost, the pressure in the heat receiving space 13 is excessively increased, and the second valve body 22 is opened.

  That is, in the normal circulation of the working fluid 12, the states shown in FIGS. 5A and 5B are repeated. However, when the heat generated from the semiconductor switching element 10 fluctuates and generates more heat than usual, When the first valve body 21 and the second valve body 22 of 5 (a) are closed, the amount of the working fluid 12 to be vaporized in the heat receiving section 4 is increased than usual, and the pressure in the heat receiving space 13 is rapidly increased than usual. There is a case.

  At this time, as shown in FIG. 5 (c), the first valve body 21 is closed due to the pressure increase in the heat receiving space 13, but when the pressure reaches a certain pressure, the second valve body 22 is opened and the check valve is opened. The pressure balance around 18 will be returned to the normal state. As a result, the first valve body 21 opens at the next moment, and the state shown in FIG. 5B is resumed, so that the supply of the working fluid 12 to the heat receiving plate 11 is resumed. ), The state of FIG. 5B is repeated.

  As described above, by providing the opening 20 in the first valve body 21 and the second valve body 22 on the upper surface of the first valve body 21 so as to cover the opening 20 as pressure balancing means, Even if the first valve body 21 is not opened due to a rise in pressure, the second valve body 22 moves upward to release the pressure, so that the pressure imbalance is reduced at the next moment. Then, the working fluid 12 is supplied from the opening 20 into the heat receiving portion 4, and the working fluid 12 can be continuously circulated.

  In the present embodiment, the check valve 18, that is, the first valve body 21 is installed substantially horizontally. However, if the first valve body 21 can be moved by the pressure of the hydraulic head of the working fluid 12, the installation direction is oblique or substantially vertical. But you can. However, considering the responsiveness (relationship between the amount of the working fluid 12 and the pressure due to the water head), substantially horizontal is preferable.

(Embodiment 2)
FIG. 6 shows a configuration in which fine holes 32 are provided in the first valve body 31 as pressure balance means. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 6A corresponds to FIG. 5A of the first embodiment, and the working fluid 12 receives the heat of the heat receiving plate 11 to start vaporization, the pressure in the heat receiving space 13 rises, and the first valve The body 21 is in a closed state. FIG. 6B corresponds to FIG. 5B of the first embodiment, and the amount of the working fluid 12 to be vaporized in the heat receiving portion 4 is reduced, the pressure in the heat receiving space 13 is lowered, and the first valve In this state, the working fluid 12 is supplied into the heat receiving part 4 with the body 21 opened.

  FIG. 6C is a cross-sectional view taken along the line AA in FIG. 6A, and a fine hole 32 is provided at a substantially central portion of the movable portion of the first valve body 31.

  The valve cover 33 is not provided with the recess 23 provided in the valve cover 24 of the first embodiment, and only the inlet 15 is provided.

  Next, the pressure balance action of the fine holes 32 provided in the first valve body 31 will be described with reference to FIG.

  FIG. 7A shows the state of the working fluid 12 in the vicinity of the fine hole 32 when the first valve body 21 of FIG. 6A is closed. FIG. 7C shows a state in which the same first valve body 21 as that in FIG. 6A is closed.

  As the pressure balance before and after the check valve 18, the pressure on the heat receiving portion 4 side is high, and the fine hole 32 is a meniscus of the working fluid 12 shown in FIG. 7A (a convex shape created by the liquid interface in the narrow tube by the interfacial tension). Or a concave curved surface), which is liquid-sealed and holds the pressure difference across the check valve 18.

  FIG. 7B shows a meniscus state when the heat generated from the semiconductor switching element 10 fluctuates and generates a larger amount of heat than usual. That is, when the heating amount increases, the state does not shift from FIG. 6A to FIG. 6B, and the first valve body 21 continues to be closed, and the heat receiving space accompanying the increase in the amount of vaporization in the heat receiving unit 4. 13 shows a state in which the meniscus of the fine hole 32 is broken due to the pressure increase in the inside 13, and the steam in the heat receiving part 4 moves from the fine hole 32 to the inflow pipe 19 (in front of the check valve 18) as a bubble. This movement reduces the pressure in the heat receiving space 13 (after the check valve 18) and increases the pressure on the inflow pipe 19 (before the check valve 18), so that the pressure balance before and after the check valve 18 is returned to the normal state. Can be returned.

  Here, the size of the fine hole 32 is determined by whether or not a meniscus can be formed by the interfacial tension of the working fluid 12, and when the working fluid 12 is water, for example, about 1 mm is preferable.

  Thus, as a pressure balance means, by providing the fine hole 32 in the first valve body 31, even if the first valve body 31 is not opened due to excessive pressure rise in the heat receiving portion 4, Since the pressure is relieved from the fine holes 32, the pressure balance before and after the check valve 18 can be returned to the normal state, so that the opening and closing of the first valve body 31 is resumed and the working fluid 12 is stably circulated into the heat receiving portion. Will be able to.

(Embodiment 3)
FIG. 8 shows a configuration in which a pressure correction slit 35 is provided in the valve cover 34 as pressure balancing means. The same components as those in the first and second embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

  8 (a) corresponds to FIG. 6 (a), FIG. 8 (b) corresponds to FIG. 6 (b), FIG. 8 (c) is a cross-sectional view taken along the line BB in FIG. The cover 34 is provided with a plurality (seven in FIG. 8) of pressure correction slits 35 having a triangular cross section.

  The pressure correction slit 35 is filled with the working fluid 12 in the state of FIG. 8A, and similarly to FIG. 7A, the working fluid 12 is provided in the slit opening on the heat receiving portion 4 side. A meniscus due to the interfacial tension is formed and sealed.

  The difference from the microscopic hole 32 of the second embodiment is that the slit section has a triangular shape, and the steam in the heat receiving portion 4 moves from the slit opening to the inside of the slit as bubbles, so that the resistance is large.

  Therefore, as shown in FIG. 8C, seven pressure correction slits 35 are provided.

  The action as the pressure balance means is the same as that of the fine hole 32 of the second embodiment, and detailed description thereof is omitted.

  As described above, by providing the pressure correction slit 35 in the valve cover 34 as the pressure balance means, the first valve body 31 is not opened due to excessive pressure rise in the heat receiving portion 4 as in the second embodiment. Even if it falls, the pressure can be released from the pressure correction slit 35, and the pressure balance before and after the check valve 18 can be returned to the normal state. Therefore, the first valve body 31 is opened and the working fluid 12 is moved into the heat receiving portion. The working fluid 12 can be circulated stably.

  In the above embodiment, the cooling device 3 applied to the electric vehicle 1 has been described. However, the inverter circuit 2 that is a power conversion device is also an electronic device, and the cooling device 3 can be applied to the electronic device. .

  The cooling device according to the present invention has a circulation path of the working fluid as one direction by setting a circulation path of the working fluid serving as a refrigerant as a heat receiving section, a heat radiation path, a heat radiation section, a return path, and the heat receiving section. A check valve for controlling the flow of the working fluid is provided in the vicinity of the heat receiving portion of the return path or in the heat receiving section, and the check valve includes a valve cover having an inlet connected to the return path; A valve holder having an outlet connected to a heat receiving portion and forming a box with the valve cover; a first valve body movably provided in a recess of the valve holder; and provided in the box. Pressure balance means for balancing the pressure before and after the check valve, and when the pressure in the heat receiving portion rises and when the first valve body is inactive, the pressure balance means causes the pressure before and after the check valve. By balancing Since an appropriate amount of working fluid can be supplied to the heat receiving section, the supplied working fluid can be rapidly vaporized, and the working fluid can be moved as a high-speed flow in the heat receiving plate portion, resulting in a heat transfer coefficient on the heat transfer surface. The cooling effect can be enhanced.

  Furthermore, even if the first valve body is not opened due to an excessive pressure rise in the heat receiving portion, the pressure balance means releases the excessive pressure in the heat receiving portion and balances the pressure before and after the check valve. The working fluid is supplied into the heat receiving portion from the heat receiving portion so that the working fluid can be circulated stably.

  For this reason, as described above, the working fluid can be rapidly vaporized in the heat receiving portion, and the working fluid can be moved as a high-speed flow in the heat receiving plate portion. As a result, the heat transfer rate on the heat transfer surface is increased, and the cooling effect In addition, the working fluid can be circulated stably.

  For this reason, it is useful for cooling power semiconductors used in power conversion devices as drive devices for electric vehicles, CPUs with high heat generation, and the like.

DESCRIPTION OF SYMBOLS 1 Electric vehicle 2 Inverter circuit 3 Cooling device 4 Heat receiving part 5 Heat radiating part 6 Heat radiating path 7 Return path 8 Heat radiating body 9 Blower 10 Semiconductor switching element 11 Heat receiving plate 12 Working fluid 13 Heat receiving space 14 Heat receiving plate cover 15 Inlet 16 Outlet 17 Introduction pipe 18 Check valve 19 Inflow pipe 20 Opening 21, 31 First valve body 22 Second valve body 23, 25 Recess 24, 33, 34 Valve cover 26 Introduction port 27 Valve holder 32 Fine hole 35 Pressure correction slit

Claims (9)

A heat receiving section having a heat receiving plate for transferring heat from the heating element to the working fluid;
A heat dissipating part for releasing the heat of the working fluid;
Consists of a heat dissipation path and a return path connecting the heat receiving section and the heat dissipation section,
A cooling device that circulates the working fluid to the heat receiving portion, the heat radiating path, the heat radiating portion, the return path, and the heat receiving portion to move heat;
A check valve for controlling the flow of the working fluid is provided in the vicinity of the heat receiving portion of the return path or in the heat receiving portion,
This check valve
A valve cover having an inlet connected to the return path; a valve holder having an outlet connected to the heat receiving portion and forming a box with the valve cover;
A first valve body provided movably in the recess of the valve holder; and a pressure balance means provided in the box for balancing the pressure before and after the check valve;
The cooling device according to claim 1, wherein the pressure balance means balances the pressure before and after the check valve when the pressure in the heat receiving portion increases and when the first valve body is not in operation. Pressure balance means
An opening provided in the first valve body, a second valve body provided on the valve cover side of the first valve body so as to cover the opening, and a recess provided in the valve cover, The cooling device according to 1. The cooling device according to claim 1 or 2, wherein the opening provided in the first valve body is a circular hole, and the size thereof is smaller than that of the inflow port connected to the return path. Pressure balance means
The cooling device according to claim 1, wherein the cooling device is a fine hole provided in the first valve body and closed by an interfacial tension of the working fluid. Pressure balance means
The cooling device according to claim 1, wherein the cooling device is a pressure correction slit provided in the valve cover. The cooling device according to any one of claims 1 to 5, wherein the first valve body is installed substantially horizontally. The cooling device according to any one of claims 1 to 6, wherein the first valve body is opened by the pressure of the hydraulic head of the working fluid accumulated on the return path side. An electronic apparatus comprising the cooling device according to claim 1. An electric vehicle comprising the cooling device according to claim 1.

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