JP2014048002A - Cooling device, electric vehicle equipped with the same, and electronic apparatus equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device which simplifies the structure while maintaining high heat exchange efficiency, and to provide an electric vehicle and an electronic apparatus which are equipped with the cooling device.SOLUTION: A heat receiver 8 includes: a heat receiving plate 12 having a heat absorption part 17 (a semiconductor switching element 6 area part), which is placed in contact with a semiconductor switching element 6 (one example of a heating element) and absorbs heat, on the rear surface side; and a heat receiving plate cover 14 which covers the front surface side of the heat receiving plate 12 through a space. An inclined part 18, which is downwardly inclined toward the heat absorption part 17, is provided at a refrigerant drop part 20 of an inflow port 15 of the heat receiving plate 12.

Description

  The present invention relates to a cooling device for an electric vehicle or an electronic device on which a power semiconductor is mounted, for example.

  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 which is a power conversion circuit.

  A plurality of power semiconductors represented by power transistors are used in the inverter circuit, and a large current of several tens of amperes flows through each power semiconductor.

  For this reason, power semiconductors generate a large amount of heat and need to be cooled.

  Therefore, for example, in the cooling device shown in Patent Document 1, in the lower heat receiver, a cycle in which the heat of the power semiconductor is taken away by the refrigerant to be vaporized, cooled by the radiator disposed at the upper part, liquefied, and dropped again at the lower part. The inverter circuit is cooled by being repeated.

  However, such a cooling device is said to be a boiling type cooling type that evaporates by boiling the refrigerant in the heat receiver, and this type receives heat with the refrigerant remaining in the heat receiver. As a conclusion, it is known that the cooling performance is low.

  On the other hand, since the refrigerant circulation type cooling type shown in Patent Document 2 receives heat in a state where the refrigerant flows in the heat receiver, the heat transfer efficiency to the refrigerant is high, and as a result, the cooling performance is remarkably high. Become.

JP-A-8-126125 JP 2009-88127 A

  In the cooling device shown in Patent Document 2, a heat receiver, a heat radiator connected to the discharge port of the heat receiver via a heat radiation path, a feedback path connecting the heat radiator and the inlet of the heat receiver, and the feedback It is the structure provided with the non-return valve interposed in the path | route.

  Further, the tip of the return path is made to rush into the heat receiver, and the refrigerant is rapidly spread in the heat receiver in a thin film state at this rush portion.

  Specifically, when the refrigerant that has returned from the return path flows into the heat receiver as the check valve is opened, a part of the refrigerant rapidly evaporates in the front end (rushing part) of the return path, and the pressure returns to that temperature. The refrigerant remaining in the path tip spreads rapidly into the heat receiver in a thin film state.

  As a result, extremely effective heat reception is performed on the inner wall surface of the heat receiver (the surface of the heat receiving plate), thereby greatly improving the cooling performance.

  However, even if the cooling performance is remarkably improved as described above, further improvement is required for mounting on various devices.

  As one of them, when the tip of the return path is rushed into the heat receiver, the position of the tip of the return path in the heat receiver cannot be visually observed, so it takes time and effort to adjust this positional relationship. There is a need for simplification.

  Accordingly, the object of the present invention is to simplify the configuration.

  In order to achieve this object, the present invention provides a heat receiver, a radiator connected to the discharge port of the heat receiver via a heat dissipation path, and a feedback connecting the heat sink and the inlet of the heat receiver. A heat-reception plate having a heat-absorbing part that contacts the heat-generating body and absorbs heat on the back side thereof, and a surface side of the heat-receiving plate. And a heat-receiving plate cover that covers the heat-receiving plate, and the refrigerant dropping portion at the inlet of the heat-receiving plate is provided with an inclined portion that is inclined low toward the heat-absorbing portion. Is achieved.

  As described above, the present invention includes a heat receiver, a radiator connected to the discharge port of the heat receiver via a heat dissipation path, a feedback path connecting the radiator and the inlet of the heat receiver, and the feedback path. The heat receiver has a heat receiving plate having a heat absorbing portion that contacts the heating element and absorbs heat on the back surface side, and a surface side of the heat receiving plate via a space. The cover has a heat receiving plate cover, and the refrigerant dripping portion at the inlet of the heat receiving plate is provided with an inclined portion that is inclined lower toward the heat absorbing portion, so that the configuration can be simplified and the productivity is high. It will be a thing.

  That is, the heat receiver of the present invention has, on the back side thereof, a heat receiving plate having a heat absorbing portion that contacts the heating element and absorbs heat, and a heat receiving plate cover that covers the surface side of the heat receiving plate via a space. The refrigerant dropping portion at the inlet of the heat receiving plate is provided with an inclined portion that is inclined downward toward the heat absorbing portion.

  That is, according to the configuration of the present invention, the refrigerant flowing into the heat receiver from the return path through the check valve is smoothly conveyed to the heat absorbing portion along the inclined portion that is inclined low toward the heat absorbing portion of the heat receiving plate. It becomes a thin film toward the discharge port side of the heat receiving plate and spreads rapidly.

  For this reason, the refrigerant can be rapidly spread in the form of a thin film on the surface of the heat receiving plate in the heat receiving device without causing the tip of the return path to enter the heat receiving device. It will be expensive.

Schematic of the electric vehicle according to the first embodiment of the present invention. Diagram showing the configuration of the cooling device Diagram showing the configuration of the heat receiver A plan view showing the shape of the heat receiving plate in the heat receiving space The perspective view explaining the composition of the radiator

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

(Embodiment 1)
As shown in FIG. 1, an electric motor 3 that drives an axle 2 of an electric vehicle 1 is connected to an inverter circuit 5 that is a power converter disposed in a vehicle interior 4 of the electric vehicle 1.

  The inverter circuit 5 includes a plurality of semiconductor switching elements 6 that supply power to the motor 3 as an example of a power semiconductor.

  Further, the inverter circuit 5 is provided with a cooling device 7 for cooling the semiconductor switching element 6 which becomes a heating element.

  The cooling device 7 includes a heat receiver 8 connected to the upper surface of the semiconductor switching element 6 in a heat transferable state, a heat radiator 9 connected to the discharge port 16 of the heat receiver 8 via a heat dissipation path 11a, and the heat dissipation And a return path 11b connecting the inlet 9 of the heat receiver 8 and the heat receiver 8 and a check valve (19 in FIGS. 2 and 3) interposed in the return path 11b.

  The radiator 9 is provided with a radiator 9a that releases heat to the outside air.

  That is, the inverter circuit 5 is arranged in the middle of the inside of the vehicle 4 close to the driver's seat side, the circulation path 11 is extended, and the radiator 9 is attached to the front grille 4a side through which the outside air easily passes.

  As shown in FIG. 2, in the cooling device 7, the circulation path 11 includes a heat receiver 8, a heat radiation path 11a, a heat radiator 9, and a return path 11b, and the discharge port 16 and the inflow port 15 are heat radiators of the thin chamber 9b. The inlet 23 and the radiator outlet 24 are connected to each other.

  That is, the discharge port 16 and the heat radiation path 11a are connected, and the inlet 15 and the thin chamber 9b are connected by the return path 11b.

  Further, the circulation path 11 formed by the heat receiver 8, the heat radiation path 11a, the heat radiator 9, and the return path 11b is in a sealed state, and the internal atmosphere is in a negative pressure state from the atmospheric pressure.

  For example, about several hundred cc (an amount sufficiently smaller than the volume of the circulation path 11) of water (an example of the refrigerant 10) is injected into the negative pressure path. (Hereinafter, water is referred to as a refrigerant).

  The inlet 15 of the heat receiving space 13 is provided with a check valve 19 that is opened by the pressure of the coolant 10 from the water head.

  In order to easily open the check valve 19 with the pressure of the refrigerant 10 that has been liquefied and stopped, it is best to use the water head pressure. Therefore, the return path 11b is formed with a downward gradient from the thin chamber 9b to the inlet 15 of the heat receiver 8, and a check valve 19 is disposed at the end thereof.

  The check valve 19 is formed, for example, from a thin metal plate (a plate having a thickness of about 100 μm).

  As shown in FIG. 3, the heat receiver 8 contacts the semiconductor switching element 6 with the back surface side thereof to absorb heat, covers the surface side of the heat receiving plate 12, and evaporates the refrigerant 10 that has flowed in. A heat receiving plate cover 14 that forms a heat receiving space 13, an inlet 15 for flowing the liquefied refrigerant 10 into the heat receiving space 13, and an outlet 16 for discharging the refrigerant 10 from the heat receiving space 13 as a gas. .

  In addition, a refrigerant dripping portion 20 is provided below the inlet 15 of the heat receiving plate 12 constituting the heat receiver 8.

  In addition, an inclined portion 18 that is inclined lower toward the heat absorbing portion 17 provided at a substantially central portion of the heat receiving plate 12 is provided in the refrigerant dropping portion 20 of the inlet 15 of the heat receiving plate 12.

  The angle of the inclined portion 18 is desirably in a range of about 3 to 10 ° at which the refrigerant 10 smoothly moves to the heat absorbing portion 17.

  In addition, the refrigerant dropping section 20 is sealed on three sides by the heat receiving plate 12 and the heat receiving plate cover 14, and the dropped refrigerant 10 flows only in the inclined direction.

  Further, in the present embodiment, the heat receiving plate cover 14 that covers the heat receiving plate 12 is provided with an inlet 15 that allows the refrigerant 10 to flow in from the top surface in the vertical direction and guides it to the refrigerant dropping portion 20. Further, the heat receiving plate cover 14 is provided with a discharge port 16 for discharging the refrigerant 10 from the side.

  In the above configuration, in the present embodiment, the return path 11b is simply connected to the inlet 15 of the heat receiver 8 and does not protrude.

  As shown in FIG. 4, an inner groove 21 is provided on the surface of the heat receiving plate 12, and the inner groove 21 extends from the heat absorbing portion 17 provided in the substantially central portion toward the discharge port 16 side from the heat absorbing portion 17. It is provided linearly in a form that spreads out.

  As shown in FIG. 5, the radiator 9 includes a thin chamber 9b and a radiator 9a. Heat transfer fins 22 are provided inside the thin chamber 9b. The thin chamber 9b is provided with a radiator inlet 23 connected to the heat dissipation path 11a and a radiator outlet 24 connected to the return path 11b. The radiator inlet 23 is provided at a position higher than the radiator outlet 24. Further, the thin chamber bottom surface 26 is inclined downward (3 to 10 °) toward the radiator outlet 24. Further, it is desirable that the heat transfer fins 22 be configured so that the contact area with the refrigerant 10 is as large as possible, so that the temperature of the refrigerant 10 passing through the heat transfer fins 22 can easily move to the heat radiator 9a. In this configuration, the connection surface between the radiator inlet 23 and the radiator outlet 24 is the side surface of the thin chamber 9b, and the heat transfer fins 22 are provided at a predetermined interval perpendicular to the connection surface. Further, the thin chamber 9b is provided with heat transfer guide fins 22a that are close to the radiator inlet 23, have end portions in close contact with the side surfaces of the thin chamber 9b, and guide the refrigerant 10 that has flowed in. The heat transfer guide fins 22 a allow the refrigerant 10 to flow up to the highest position of the thin chamber bottom surface 26. Of course, other arrangements that can achieve the same effect may be used.

  Further, the radiator 9a is connected to the lower outer surface of the thin chamber 9b in a heat transferable state. Further, the heat dissipating body 9a is provided with heat dissipating fins 25 formed by thinly forming aluminum or copper in a strip shape at a predetermined interval.

  In the above configuration, when the semiconductor switching element 6 of the inverter circuit 5 starts to operate, electric power is supplied to the electric motor 3 and the electric vehicle 1 starts to move.

  At this time, since a large current flows through the semiconductor switching element 6, at least several percent of the total power is lost and a large amount of heat is generated.

  As shown in FIG. 2, the heat generated from the semiconductor switching element 6 is transferred to the refrigerant 10 in which the liquid is dropped through the heat receiving plate 12. The refrigerant 10 is instantly vaporized by the transferred heat, flows from the discharge port 16 through the heat radiation path 11a, and the heat radiator 9 releases the heat to the outside air. The refrigerant 10 that has released heat by the action of the radiator 9 liquefies and flows through the return path 11 b and accumulates on the check valve 19 of the inlet 15. The liquefied refrigerant 10 gradually increases in the return path 11b, and the check valve 19 is pushed down and opened by the balance between the pressure of the water head and the pressure of the heat receiving space 13, and again enters the heat receiving space 13. And flows in.

  In this way, the refrigerant 10 is repeatedly circulated in the cooling device 7 to cool the semiconductor switching element 6.

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

  As shown in FIG. 3, in the heat receiving space 13, the refrigerant 10 is dropped as droplets from the inlet 15 through the return path 11 b through the check valve 19 into the refrigerant dropping unit 20.

  The refrigerant 10 dropped into the heat receiving space 13 is smoothly conveyed to the heat absorbing portion 17 along the inclined portion 18 that is inclined downward toward the heat absorbing portion 17 of the heat receiving plate 12.

  Next, as shown in FIG. 4, the refrigerant 10 is diffused along an inner groove 21 provided on the surface of the heat receiving plate 12. At this time, since the inner groove 21 has a shape in which the flow path radially expands, the refrigerant 10 can be spread on the heat receiving plate 12 as a thin film. Since the heat receiving plate 12 is in contact with the semiconductor switching element 6, the thin film of the refrigerant 10 is heated and vaporized instantly.

  Since the atmospheric pressure in the heat receiving space 13 is set lower than the atmospheric pressure, the refrigerant 10 can be vaporized at a temperature lower than the boiling of water in the atmospheric pressure even if water is used.

  As in the present embodiment, by setting the atmospheric pressure to −97 KPa and keeping the inside of the circulation path 11 (shown in FIG. 2) in a saturated state, the boiling temperature corresponding to the outside air temperature is determined and water is easily vaporized. At this time, the semiconductor switching element 6 can be deprived of heat and cooled. In other words, the heat of the semiconductor switching element 6 is taken away by the latent heat of evaporation of water, and the water is heated and vaporized in an instant, so compared with the one that simply heats the accumulated water and makes it boil, The amount of heat taken away can be increased.

  Further, when the refrigerant 10 is vaporized, the pressure in the heat receiving space 13 increases. However, the refrigerant 10 does not flow backward due to the action of the check valve 19 and returns to the return path 11b side, and heat is reliably radiated from the discharge port 16. It can be discharged to the path 11a.

  Further, the mechanism of heat dissipation in the radiator 9 will be described.

  As shown in FIG. 5, the vaporized refrigerant 10 flows into the thin chamber 9b from the radiator inlet 23 through the heat dissipation path 11a. The refrigerant 10 that has flowed in comes into contact with the heat transfer fins 22 provided in the thin chamber 9b, and condenses (liquefies) due to the difference in outside air temperature. At that time, the heat in the thin chamber 9b is released to the outside air through the heat dissipating fins 25 of the heat dissipating body 9a connected to the lower outer surface in a heat transferable state. The liquefied refrigerant 10 moves toward the radiator outlet 24 along the inclined bottom surface of the thin chamber 9b and moves to the heat receiver 8 from the return path 11b.

  By operating the cooling device 7 in this way, a regular heat receiving and releasing cycle can be performed, and the semiconductor switching element 6 can be cooled by continuously evaporating the refrigerant 10 in the heat receiving space 13. A cooling effect can be obtained.

  Further, since the refrigerant 10 vaporized by the increased pressure in the heat receiving space 13 is caused to flow through the heat radiation path 11a, the moving speed can be increased compared to the liquid, and the heat receiver 8 and the heat radiator 9 are arranged apart from each other. You can also In other words, the inverter circuit 5 that is sensitive to dust and water droplets and the radiator 9 that is to be cooled efficiently by applying outside air can be installed separately such as the front grill 4a of the electric vehicle 1 and the interior 4 of the electric vehicle 1. Driving performance can be ensured.

  Now, the basic part of the present embodiment has been described as above, but a feature that further enhances the effect of the mechanism will be described.

  Although the configuration has already been described in the embodiment, in the present embodiment, the heat receiver 8, the radiator 9 connected to the discharge port 16 of the heat receiver 8 through the heat radiation path 11 a, A return path 11b connected to the inlet 15 of the heat receiver 8 and a check valve 19 interposed in the return path 11b are provided. The heat receiver 8 has a heat receiving plate 12 having a heat absorbing portion 17 that contacts the semiconductor switching element 6 and absorbs heat on the back surface side, and a heat receiving plate cover that covers the surface side of the heat receiving plate 12 via a space. 14 and the refrigerant dropping part 20 of the inlet 15 of the heat receiving plate 12 is provided with an inclined part 18 inclined downward toward the heat absorbing part 17.

  For this reason, in the present embodiment, as shown in FIG. 3, since the return path 11 b is simply connected to the inlet 15 of the heat receiver 8 so that it does not protrude, There is no need to work up to which part the tip of the return path 11b is inserted. That is, the configuration can be simplified and the productivity can be increased.

  Further, even in such a configuration, since the thin layered water can be sufficiently spread on the heat absorbing portion 17 (semiconductor switching element 6 region portion) in the heat receiving space 13, extremely high heat transfer efficiency can be obtained, and as a result. As a result, the cooling efficiency is also high.

  Further, the outlet 16 of the heat receiver 8 is arranged on the side of the heat receiver 8. For this reason, in this Embodiment, as shown in FIG. 2, the height direction of the heat receiver 8 can be made low, and the installation to the limited space of the vehicle interior 4 is attained.

  Further, as shown in FIG. 4, an inner groove 21 is provided on the surface of the heat receiving plate 12, and the inner groove 21 extends from the heat absorbing portion 17 to the entire heat receiving space 13 from the heat absorbing portion 17 toward the discharge port 16. It is provided linearly. Since the thin layered refrigerant 10 can be further expanded in the entire heat receiving space 13, extremely high heat transfer efficiency is obtained, and as a result, the cooling efficiency is also high.

  The radiator 9 includes a thin chamber 9b and a radiator 9a, and heat transfer fins 22 are provided inside the thin chamber 9b. Further, the connection port of the radiator inlet 23 is provided at a position higher than the connection port of the radiator outlet 24. Further, the thin chamber bottom surface 26 is inclined downward (3 to 10 °) toward the radiator outlet 24. For this reason, in the present embodiment, the refrigerant 10 that has flowed from the radiator inlet 23 passes through the flow path surrounded by the heat transfer guide fins 22a and the outer shape of the thin chamber 9b at the top of the thin chamber bottom surface 26. After that, it is condensed (liquefied) due to the outside air temperature difference while contacting many heat transfer fins 22 provided in the thin chamber 9b, and the radiator outlet 24 along the inclined thin chamber bottom surface 26. Can go smoothly. At that time, the heat in the thin chamber 9b is released to the outside air through the heat dissipating fins 25 of the heat dissipating body 9a connected to the lower outer surface in a heat transferable state. By setting it as such a structure, even if the dimension of the height direction of the thin chamber 9b is made low, heat dissipation performance can be maintained. Therefore, the dimension in the height direction of the entire cooling device 7 can be reduced, and installation in a limited space inside the vehicle 4 is possible.

  Further, since the radiator 9 is provided with the radiator 9a on the lower and outer surfaces of the thin chamber 9b, the liquefied refrigerant 10 flows on the bottom surface of the thin chamber 9b, so that the heat dissipation efficiency is further improved. As a result, the cooling efficiency is also high. In addition, this cooling system (refrigerant circulation type cooling type) has a characteristic that the radiator 9 must be disposed at the highest position in the cooling device 7, so that the radiator 9a is positioned below the thin chamber 9b. By doing so, the dimension of the whole cooling device 7 in the height direction can be further reduced, and installation in a limited space in the vehicle interior 4 becomes possible.

  In the present embodiment, the heat receiving plate cover 14 that covers the heat receiving plate 12 is provided with the inlet 15 that allows the refrigerant 10 to flow in the vertical direction from the top surface and leads to the refrigerant dripping portion 20. You may provide in the side of the heat-receiving plate cover 14, and the same effect is obtained.

  Therefore, it is useful also for electronic devices, such as a power converter as a drive device of an electric vehicle, and a high-speed arithmetic processing unit.

DESCRIPTION OF SYMBOLS 1 Electric vehicle 2 Axle 3 Electric motor 4 Car interior 4a Front grille 5 Inverter circuit 6 Semiconductor switching element 7 Cooling device 8 Heat receiver 9 Heat radiator 9a Heat radiator 9b Thin chamber 10 Refrigerant 11 Circulation path 11a Heat radiation path 11b Return path 12 Heat receiving plate 13 Heat receiving space 14 Heat receiving plate cover 15 Inflow port 16 Discharge port 17 Heat absorbing part 18 Inclined part 19 Check valve 20 Refrigerant dripping part 21 Inner groove 22 Heat transfer fin 22a Heat transfer guide fin 23 Radiator inlet 24 Radiator outlet 25 Radiation fin 26 Thin chamber bottom

Claims (7)

A heat receiver, a radiator connected to the outlet of the heat receiver via a heat dissipation path, a feedback path connecting the heat sink and the inlet of the heat receiver, and a check valve interposed in the feedback path. The heat receiver has a heat receiving plate having a heat absorbing portion that contacts the heating element and absorbs heat on the back side thereof, and a heat receiving plate cover that covers the surface side of the heat receiving plate with a space interposed therebetween. And the cooling device which provided the inclination part inclined low toward the said heat absorption part in the refrigerant | coolant dripping part of the said inflow port of the said heat receiving plate. The cooling device according to claim 1, wherein at least one of the outlet and the inlet of the heat receiver is disposed on a side of the heat receiver. The cooling device according to claim 1 or 2, wherein a groove is formed on the surface of the heat receiving plate from the heat absorbing portion toward the discharge port side. The radiator is composed of a thin chamber and a radiator, heat transfer fins are provided inside the thin chamber, and a connection port between the thin chamber and the heat dissipation path is provided at a position higher than a connection port of the return path. The cooling device according to any one of 1 to 3. The cooling device according to any one of claims 1 to 4, wherein the radiator is provided with a radiator on a lower outer surface of the thin chamber. An electric vehicle that mounts the cooling device according to any one of claims 1 to 5 and that cools a power change device that drives an electric motor that drives an axle. An electronic device that mounts the cooling device according to claim 1 and cools a heating element.

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