WO2021117106A1

WO2021117106A1 - Cooling device and power conversion device

Info

Publication number: WO2021117106A1
Application number: PCT/JP2019/048134
Authority: WO
Inventors: 幸夫中嶋; 裕之牛房
Original assignee: 三菱電機株式会社
Priority date: 2019-12-09
Filing date: 2019-12-09
Publication date: 2021-06-17
Also published as: JPWO2021117106A1; CN114746711A; DE112019007956T5; JP7199574B2

Abstract

A cooling device (1) comprises: a heat-receiving block (11); and at least one heat pipe (12) that has a portion attached to the heat-receiving block (11), extends in a direction away from the heat-receiving block (11), and is filled with a refrigerant (13). The cooling device (1) further comprises: at least one heat-transfer member (15) that is provided inside at least one of the heat pipes (12) and extends in a direction away from the heat-receiving block (11); and a fin (14) that is attached to the outer surface of the heat pipe (12). One end of the heat-transfer member (15) is adjacent to the inner wall of the portion of the heat pipe (12) attached to the heat-receiving block (11), and the other end of the heat transfer member (15) is located farther from the heat-receiving block (11) than the fin (14) is.

Description

Cooling device and power converter

This disclosure relates to a cooling device and a power conversion device.

Some power converters have a cooling device that is thermally connected to the electronic component that is a heating element in order to prevent damage to the electronic component due to heat generated during energization. The cooling device cools the electronic component by dissipating the heat transferred from the electronic component to the surrounding air. An example of this type of power conversion device is disclosed in Patent Document 1. The power conversion device disclosed in Patent Document 1 includes a heat receiving member to which electronic components are fixed, a plurality of heat pipes, and a plurality of heat radiating fins. Each of the plurality of heat pipes is attached to the heat receiving block and extends in a direction away from the heat receiving block.

Refrigerant is sealed in each heat pipe. The refrigerant is vaporized by transferring heat from the electronic components via the heat receiving member. The vaporized refrigerant moves toward the tip inside the heat pipe and transfers heat to the surrounding air through the heat pipe and a plurality of heat radiating fins attached to the heat pipe. By transferring heat to the air, the temperature of the refrigerant drops and the refrigerant liquefies. The liquefied refrigerant flows through the heat pipe toward the heat receiving block. In this way, the refrigerant repeatedly vaporizes and liquefies and circulates inside the heat pipe, thereby cooling the electronic components.

Japanese Patent No. 4929325

If the heat pipe of the power conversion device disclosed in Patent Document 1 is installed in a place where it comes into contact with air below the melting point of the refrigerant, the liquefied refrigerant may freeze after being dissipated through the heat pipe and the heat radiation fins. is there. For example, when pure water is sealed in a heat pipe as a refrigerant and the heat pipe is installed in a place where it comes into contact with air at 0 degrees Celsius or less, the pure water sealed inside the heat pipe is the tip of the heat pipe. May freeze in. If the refrigerant freezes at the tip of the heat pipe, the refrigerant cannot return to the heat receiving block, so that the heat generated by the electronic components cannot be transferred to the refrigerant through the heat receiving block. Therefore, the heat generated in the electronic component cannot be dissipated from the heat pipe and the heat radiation fins via the refrigerant circulating in the heat pipe, and the electronic component cannot be cooled.

The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide a cooling device and a power conversion device capable of cooling a heating element even in a low temperature environment in which a refrigerant can freeze.

In order to achieve the above object, the cooling device of the present disclosure includes a heat receiving block, at least one heat pipe, at least one heat transfer member, and fins. A heating element is attached to the heat receiving block. A part of the at least one heat pipe is attached to the heat receiving block, extends in a direction away from the heat receiving block, and is filled with a refrigerant. The at least one heat transfer member is provided inside at least one of the heat pipes and extends in a direction away from the heat receiving block. The fins are attached to the outer surface of the heat pipe. One end of the heat transfer member is adjacent to a part of the inner wall attached to the heat receiving block of the heat pipe. The other end of the heat transfer member is located farther from the heat receiving block than the fins.

The cooling device according to the present disclosure includes a heat transfer member provided inside the heat pipe. By providing the heat transfer member, the frozen refrigerant inside the heat pipe can be quickly melted. As a result, the heating element can be cooled even in a low temperature environment.

Circuit diagram of the power conversion device according to the first embodiment Sectional drawing of the power conversion apparatus which concerns on Embodiment 1. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 2 of the power conversion device according to the first embodiment. Perspective view of the cooling device according to the first embodiment FIG. 4 is a cross-sectional view taken along the line BB of the cooling device according to the first embodiment. The figure which shows the frozen state of the refrigerant which the cooling device which concerns on Embodiment 1 has. Sectional drawing of the cooling apparatus which concerns on Embodiment 2. Sectional drawing of the cooling apparatus which concerns on Embodiment 3. Top view of the heat transfer member according to the fourth embodiment Sectional drawing of the cooling apparatus which concerns on Embodiment 5. Top view of the heat transfer member according to the fifth embodiment Sectional drawing of the cooling apparatus which concerns on Embodiment 6. Partial view of the cross-sectional view taken along the line CC of FIG. 12 of the heat pipe according to the sixth embodiment. Sectional drawing of the cooling apparatus which concerns on Embodiment 7. Partial view of the cross-sectional view taken along the line DD of FIG. 14 of the heat pipe according to the seventh embodiment. Sectional drawing of the 1st modification of the cooling apparatus which concerns on embodiment Sectional drawing of the 2nd modification of the cooling apparatus which concerns on embodiment Sectional drawing of the first modification of the heat pipe which concerns on embodiment Sectional drawing of the 2nd modification of the heat pipe which concerns on embodiment Perspective view of a third modification of the cooling device according to the embodiment FIG. 20 is a cross-sectional view taken along the line EE of FIG. 20 of a third modification of the cooling device according to the embodiment. Sectional drawing of the 4th modification of the cooling apparatus which concerns on embodiment

Hereinafter, the cooling device and the power conversion device according to the embodiment of the present disclosure will be described in detail with reference to the drawings. In the figure, the same or equivalent parts are designated by the same reference numerals.

(Embodiment 1)
Taking a power conversion device mounted on a railroad vehicle as an example, the power conversion device according to the first embodiment and a cooling device for cooling a heating element included in the power conversion device will be described.
The power conversion device 30 shown in FIG. 1 converts DC power supplied from a power source (not shown) into three-phase AC power for supplying to the motor M1 which is a load, and supplies the three-phase AC power to the motor M1. The electric motor M1 is, for example, a three-phase induction motor.

Specifically, the power conversion device 30 includes a primary terminal 31a connected to a power supply, a grounded primary terminal 31b, a filter capacitor FC1 whose ends are connected to the

primary terminals

31a and 31b, and a direct current supplied from the power supply. It includes a power conversion unit 32 that converts electric power into three-phase AC electric power and supplies it to the electric motor M1. The power conversion unit 32 includes

switching elements

33a and 33b corresponding to the U phase,

switching elements

33c and 33d corresponding to the V phase, and

switching elements

33e and 33f corresponding to the W phase. A switching control unit (not shown) switches the switching elements 33a-33f on and off, so that the power conversion unit 32 converts the DC power supplied from the power source into three-phase AC power and supplies it to the motor M1.

The power conversion device 30 is provided with a cooling device in order to prevent the electronic components from breaking down due to heat generation of the electronic components when the power conversion unit 32 is energized. Specifically, as shown in FIG. 3 which is a cross-sectional view taken along the line AA of FIGS. 2 and 2, the power conversion device 30 has an electronic component 33 which is a heating element and an electronic component 33 inside. It includes a housing 34 that accommodates and has an opening 34a, a cooling device 1 that is attached to the housing 34 while closing the opening 34a of the housing 34, and a cover 35 that covers the cooling device 1.

The electronic component 33 represents an arbitrary heating element such as a switching element 33a-33f, a diode, or a thyristor. Further, the electronic component 33 is attached to the first main surface 11a of the heat receiving block 11 included in the cooling device 1 described later.

The opening 34a of the housing 34 is closed by the first main surface 11a of the heat receiving block 11 of the cooling device 1. By closing the opening 34a with the cooling device 1, it is possible to prevent air, moisture, dust, and the like from flowing into the housing 34.

The cover 35 has intake / exhaust ports 35a on two opposite surfaces. The cooling air flowing in from one intake / exhaust port 35a flows while contacting the cooling device 1, and is discharged from the other intake / exhaust port 35a. The heat generated in the electronic component 33 is transferred to the cooling air via the cooling device 1, so that the electronic component 33 is cooled.

As shown in FIG. 5, which is a cross-sectional view taken along the line BB of FIGS. 2, 3, 4, and 4, the cooling device 1 has a heat receiving block 11 to which the electronic component 33 is attached and a part of the cooling device 1. It includes at least one heat pipe 12 that is attached to the block 11 and extends away from the heat receiving block 11. The refrigerant 13 is sealed inside each heat pipe 12. The cooling device 1 further includes fins 14 attached to the outer surface of the heat pipe 12 and at least one heat transfer member 15 provided inside at least one of the heat pipes 12. In order to avoid complication of the figure, the description of the fin 14 is omitted in FIG. Although the details will be described later, since the cooling device 1 is provided with the heat transfer member 15, even if the cooling device 1 is in a low temperature environment and the refrigerant 13 freezes, the refrigerant 13 is quickly melted and the electronic component 33 is formed. It becomes possible to cool.

Each part of the cooling device 1 having the above configuration will be described by taking as an example a configuration in which the cooling device 1 includes four heat pipes 12. In FIGS. 2 to 5, the Z axis indicates the vertical direction. The X-axis extends in a direction orthogonal to each of the first main surface 11a and the second main surface 11b of the heat receiving block 11. The Y-axis is orthogonal to the X-axis and the Z-axis.

The heat receiving block 11 has a first main surface 11a and a second main surface 11b facing in the extending direction of the X axis. An electronic component 33 is attached to the first main surface 11a. A groove 11c into which the heat pipe 12 is inserted is formed on the second main surface 11b. The heat receiving block 11 is made of a material having high thermal conductivity, for example, a metal such as copper or aluminum.

Each heat pipe 12 has a mother pipe 12a and a plurality of branch pipes 12b communicating with the mother pipe 12a. Specifically, each heat pipe 12 has a mother pipe 12a and four branch pipes 12b. The mother tube 12a is inserted into the groove 11c formed in the heat receiving block 11 and is fixed to the heat receiving block 11 by an arbitrary fixing method such as adhesion with an adhesive or soldering. The mother tube 12a is fixed to the heat receiving block 11 in a partially exposed state. The mother tube 12a is made of a material having high thermal conductivity, for example, a metal such as copper or aluminum.

The branch pipe 12b is fixed to the mother pipe 12a by welding, soldering, etc., and communicates with the mother pipe 12a. Further, the branch pipe 12b extends in a direction away from the heat receiving block 11, specifically, in a direction away from the second main surface 11b. The branch pipe 12b is made of a material having high thermal conductivity, for example, a metal such as copper or aluminum.

The refrigerant 13 is sealed in each heat pipe 12. At room temperature, the refrigerant 13 exists in a gas-liquid two-phase state. The refrigerant 13 is a substance that is vaporized by the heat transmitted from the electronic component 33 and liquefied by radiating heat to the air around the cooling device 1 via the heat pipe 12 and the fins 14, for example, water.

Each fin 14 is attached to the outer surface of the heat pipe 12. Specifically, the fin 14 has a through hole and is fixed to the branch pipe 12b with the support pipe 12b passing through the through hole. The fin 14 is made of a material having high thermal conductivity, for example, a metal such as copper or aluminum. When the power conversion device 30 is mounted on a vehicle, it is preferable to install the power conversion device 30 so that the main surface of the fins 14 faces the traveling direction of the vehicle. By installing the power conversion device 30 as described above, the running wind flows smoothly between the fins 14, and the cooling efficiency of the cooling device 1 becomes high.

The heat transfer member 15 is provided inside at least one of the heat pipes 12. Further, the heat transfer member 15 extends in a direction away from the heat receiving block 11, specifically, in a direction away from the second main surface 11b. The heat transfer member 15 is made of a material having high thermal conductivity, for example, a metal such as copper or aluminum. Further, the value of the thermal conductivity of the heat transfer member 15 is preferably equal to or higher than the value of the thermal conductivity of the heat pipe 12. For example, the heat transfer member 15 may be made of the same material as the heat pipe 12.

One end of the heat transfer member 15 is adjacent to a part of the inner wall attached to the heat receiving block 11 of the heat pipe 12. Specifically, one end of the heat transfer member 15 is adjacent to the inner wall of the mother tube 12a. The other end of the heat transfer member 15 is located farther from the heat receiving block 11 than the fin 14. Then, the heat transfer member 15 transfers heat from one end to the other end. The other end of the heat transfer member 15 is preferably adjacent to the tip far from the heat receiving block 11 of the heat pipe 12. In other words, it is preferable that the other end of the heat transfer member 15 is adjacent to the tip of the support pipe 12b, that is, the inner wall of one end far from the heat receiving block 11 of the support pipe 12b. Specifically, it is preferable that the other end of the heat transfer member 15 is adjacent to the tip of the branch pipe 12b to such an extent that heat can be transferred to the refrigerant 13 frozen at the tip of the branch pipe 12b.

In the first embodiment, a heat transfer member 15 having a rod shape is provided inside each branch pipe 12b, and one end of the heat transfer member 15 is welded and soldered to the inner wall of the mother pipe 12a to which the support pipe 12b is attached. It is fixed by etc. The other end of the heat transfer member 15 is located adjacent to the tip of the branch pipe 12b. The heat transfer member 15 preferably has a shape that does not interfere with the circulation of the refrigerant 13, which will be described later. For example, the inner diameter of the heat transfer member 15 may be 20% or less of the inner diameter of the branch pipe 12b. By providing the heat transfer member 15, it is possible to melt the frozen refrigerant 13 at the tip of the branch pipe 12b and cool the electronic component 33 even in a low temperature environment, as will be described later.

The mechanism by which the cooling device 1 having the above configuration cools the electronic component 33 will be described. When the electronic component 33 generates heat, heat is transferred from the electronic component 33 to the refrigerant 13 via the heat receiving block 11 and the mother pipe 12a. As a result, the temperature of the refrigerant 13 rises, and a part of the refrigerant 13 vaporizes. The vaporized refrigerant 13 flows from the mother pipe 12a into the branch pipe 12b, and further moves inside the branch pipe 12b toward the upper end of the branch pipe 12b in the vertical direction.

While moving inside the branch pipe 12b toward the upper end in the vertical direction of the branch pipe 12b, the refrigerant 13 dissipates heat to the air around the cooling device 1 via the branch pipe 12b and the fins 14. As the refrigerant 13 dissipates heat, the temperature of the refrigerant 13 drops. As a result, the refrigerant 13 is liquefied. The liquefied refrigerant 13 passes through the inner wall of the branch pipe 12b and returns to the mother pipe 12a. When the liquefied refrigerant 13 transfers heat from the electronic component 33 via the heat receiving block 11, it vaporizes again, flows into the branch pipe 12b, and moves toward the upper end of the branch pipe 12b in the vertical direction. As the refrigerant 13 circulates by repeating the above-mentioned vaporization and liquefaction, the heat generated in the electronic component 33 is dissipated to the air around the cooling device 1, specifically, the air around the branch pipe 12b and the fin 14. , The electronic component 33 is cooled.

Further, when the electronic component 33 generates heat and heat is transferred from the electronic component 33 to the refrigerant 13 via the heat receiving block 11 and the mother pipe 12a, the temperature difference between the unvaporized refrigerant 13, that is, the liquid refrigerant 13. And convection occurs. Due to convection, the refrigerant 13 diffuses and transfers the heat transferred from the electronic component 33 in the Y-axis direction, so that the electronic component 33 is efficiently cooled.

When the refrigerant 13 is frozen, the circulation and convection of the refrigerant 13 described above do not occur, so that the cooling device 1 cannot cool the electronic component 33. Specifically, when the air around the cooling device 1 becomes 0 degrees Celsius or less, the refrigerant 13 which is water may freeze. For example, as shown in FIG. 6, the refrigerant 13 may freeze and adhere to the inner wall at the tip of the branch pipe 12b. In order to suppress a decrease in the cooling efficiency of the cooling device 1 due to freezing of the refrigerant 13, it is necessary to melt the refrigerant 13.

The mechanism of the cooling device 1 that melts the frozen refrigerant 13 will be described. When the electronic component 33 generates heat, heat is transferred to one end of the heat transfer member 15 adjacent to the heat receiving block 11 via the heat receiving block 11 and the mother tube 12a. Then, heat is transferred from one end to the other end of the heat transfer member 15, and heat is transferred from the other end of the heat transfer member 15 to the frozen refrigerant 13 adhering to the inner wall of the tip of the branch pipe 12b.

In a conventional cooling device not provided with the heat transfer member 15, a temperature difference occurs in the heat pipe in a low temperature environment, and the refrigerant may freeze at the tip of the heat pipe. In this case, it is necessary to transfer heat to the refrigerant via the heat pipe to melt the refrigerant, but the heat transferred from the electronic components to the heat pipe is dissipated to the outside air before reaching the tip of the heat pipe. It ends up. Therefore, the conventional cooling device cannot quickly melt the frozen refrigerant. As a result, the refrigerant cannot return to the heat receiving block, and the heat generated in the electronic component may not be transferred to the refrigerant through the heat receiving block. Therefore, the heat generated in the electronic component cannot be dissipated from the heat pipe and the heat radiating fin via the refrigerant, and the electronic component may not be cooled.

On the other hand, since the cooling device 1 according to the first embodiment includes the heat transfer member 15, heat is transferred to the frozen refrigerant 13 more quickly than the conventional cooling device without being affected by the outside air. As a result, the cooling device 1 can quickly melt the frozen refrigerant 13. Further, by providing the heat transfer member 15, the temperature difference of the heat pipe 12 becomes smaller than that of the conventional cooling device. Therefore, the refrigerant 13 of the cooling device 1 can circulate even in a low temperature environment, and the electronic component 33 can be cooled.

As described above, according to the cooling device 1 according to the first embodiment, by providing the heat transfer member 15, the frozen refrigerant 13 can be quickly melted. As a result, the electronic component 33 can be cooled by the cooling device 1 even in a low temperature environment.

(Embodiment 2)
The shape and fixing method of the heat transfer member 15 are arbitrary as long as they have a shape and a fixing method capable of melting the frozen refrigerant 13. In addition to the configuration of the cooling device 1 according to the first embodiment, the cooling device 2 according to the second embodiment shown in FIG. 7 further includes a heat insulating material 16 fixed to the inner wall of the tip of the branch pipe 12b. The mechanism by which the cooling device 2 cools the electronic component 33 and the mechanism by which the cooling device 2 melts the frozen refrigerant 13 are the same as those of the cooling device 1.

The heat insulating material 16 is adhered to the inner wall at the tip of the branch pipe 12b, for example, with an adhesive. Further, the heat insulating material 16 has a fitting hole 16a into which the heat transfer member 15 is fitted. The heat insulating material 16 is made of a material having a low thermal conductivity, for example, resin, rubber, or the like. Since the heat insulating material 16 has a low thermal conductivity, the heat of the air around the cooling device 2 is not easily transferred to the heat transfer member 15 fitted to the heat insulating material 16. Therefore, when melting the frozen refrigerant 13, the heat transfer member 15 is not easily affected by the temperature of the air around the cooling device 2.

One end of the heat transfer member 15 is fixed to the inner wall of the mother tube 12a as in the first embodiment. The other end of the heat transfer member 15 is inserted into the fitting hole 16a of the heat insulating material 16 and fitted. As a result, both ends of the heat transfer member 15 are fixed. Similar to the first embodiment, the heat transfer member 15 transfers heat from one end to the other end.

As described above, according to the cooling device 2 according to the second embodiment, by fixing the heat transfer member 15 at a plurality of places, when the cooling device 1 is installed in a place subject to vibration, it receives vibration. The heat transfer member 15 is prevented from coming into contact with the heat pipe 12 and being damaged.

Further, by fitting the heat transfer member 15 to the heat insulating material 16 and fixing the heat transfer member 15, the frozen refrigerant 13 can be transferred without the heat transfer member 15 being affected by the temperature of the air around the cooling device 2. It becomes possible to melt.

(Embodiment 3)
The shape and fixing method of the heat transfer member 15 are arbitrary as long as they have a shape and a fixing method capable of melting the frozen refrigerant 13. Each of the cooling devices 3 according to the third embodiment shown in FIG. 8 includes at least one heat transfer member 17 provided inside at least one of the heat pipes 12. The mechanism by which the cooling device 3 cools the electronic component 33 and the mechanism by which the cooling device 3 melts the frozen refrigerant 13 are the same as those of the cooling device 1.

The heat transfer member 17 is provided inside at least one of the heat pipes 12 and extends in a direction away from the heat receiving block 11, specifically, in a direction away from the second main surface 11b. The heat transfer member 17 is made of a material having high thermal conductivity, for example, a metal such as copper or aluminum. Further, the value of the thermal conductivity of the heat transfer member 17 is preferably equal to or higher than the value of the thermal conductivity of the heat pipe 12. For example, the heat transfer member 17 may be made of the same material as the heat pipe 12.

One end of the heat transfer member 17 is adjacent to a part of the inner wall attached to the heat receiving block 11 of the heat pipe 12. Specifically, one end of the heat transfer member 17 is adjacent to the inner wall of the mother tube 12a. The other end of the heat transfer member 17 is located farther from the heat receiving block 11 than the fin 14. Then, the heat transfer member 17 transfers heat from one end to the other end. The other end of the heat transfer member 17 is preferably adjacent to the tip far from the heat receiving block 11 of the heat pipe 12, that is, adjacent to the inner wall of the tip of the branch pipe 12b. Specifically, it is preferable that the other end of the heat transfer member 17 is adjacent to the tip of the branch pipe 12b to such an extent that heat can be transferred to the refrigerant 13 frozen at the tip of the branch pipe 12b.

In the third embodiment, a heat transfer member 17 having a tapered rod shape is provided inside each branch pipe 12b, and one end of the heat transfer member 17 is welded to the inner wall of the mother pipe 12a to which the support pipe 12b is attached. It is fixed by soldering or the like. The other end of the heat transfer member 17 is located adjacent to the tip of the branch pipe 12b. By providing the heat transfer member 17, the refrigerant 13 frozen at the tip of the branch pipe 12b can be melted, and the electronic component 33 can be cooled even in a low temperature environment.

If heat is transferred to the tip of the branch pipe 12b while the refrigerant 13 repeatedly vaporizes and liquefies and circulates inside the branch pipe 12b, the cooling efficiency is lowered because the fin 14 is not attached to the tip of the branch pipe 12b. .. In the third embodiment, the area of the cross section orthogonal to the stretching direction of one end of the heat transfer member 17 is larger than the area of the cross section orthogonal to the stretching direction of the other end of the heat transfer member 17. Therefore, as compared with the cooling device 1, heat is less likely to be transferred from the heat transfer member 17 to the tip of the branch pipe 12b, and the cooling efficiency is lowered while the refrigerant 13 repeatedly vaporizes and liquefies and circulates inside the branch pipe 12b. It is suppressed. The other end of the heat transfer member 17 may have a cross-sectional size sufficient to melt the frozen refrigerant 13.

As described above, according to the cooling device 3 according to the third embodiment, by providing the heat transfer member 17, the cooling efficiency while the refrigerant 13 repeatedly vaporizes and liquefies and circulates inside the branch pipe 12b. The electronic component 33 can be cooled by the cooling device 3 even in a low temperature environment while suppressing the decrease in the cooling device.

(Embodiment 4)
A modified example of the heat transfer member capable of quickly melting the frozen refrigerant 13 will be described in the fourth embodiment. The structure of the cooling device 3 according to the fourth embodiment is different from the cooling device 3 according to the third embodiment in that the heat transfer member 18 shown in FIG. 9 is provided. The mechanism by which the cooling device 3 cools the electronic component 33 and the mechanism by which the cooling device 3 melts the frozen refrigerant 13 are the same as those of the cooling device 1.

The heat transfer member 18 is provided inside at least one of the heat pipes 12 and extends in a direction away from the heat receiving block 11, specifically, in a direction away from the second main surface 11b. The heat transfer member 18 is made of a material having high thermal conductivity, for example, a metal such as copper or aluminum. Further, the value of the thermal conductivity of the heat transfer member 18 is preferably equal to or higher than the value of the thermal conductivity of the heat pipe 12. For example, the heat transfer member 18 may be made of the same material as the heat pipe 12.

One end of the heat transfer member 18 is adjacent to a part of the inner wall attached to the heat receiving block 11 of the heat pipe 12. Specifically, one end of the heat transfer member 18 is adjacent to the inner wall of the mother tube 12a. Further, the heat transfer member 18 has at least one branch and has a plurality of other ends located farther from the heat receiving block 11 than the fin 14. Then, the heat transfer member 18 transfers heat from one end to the plurality of other ends. It is preferable that the other ends of the heat transfer member 18 are adjacent to the tip far from the heat receiving block 11 of the heat pipe 12, that is, the inner wall of the tip of the branch pipe 12b. Specifically, it is preferable that the other ends of the heat transfer member 18 are adjacent to the tip of the branch pipe 12b to such an extent that heat can be transferred to the refrigerant 13 frozen at the tip of the branch pipe 12b.

Since the heat transfer member 18 has at least one branch, the surface area of the heat transfer member 18 is larger than the surface area of the heat transfer member 17. As a result, the frozen refrigerant 13 can be melted more quickly than the heat transfer member 17.

In the fourth embodiment, a heat transfer member 18 having a branch is provided inside each branch pipe 12b, and one end of the heat transfer member 18 is welded, soldered, or the like to the inner wall of the mother pipe 12a to which the support pipe 12b is attached. It is fixed. Further, the other ends of the heat transfer member 18 are located adjacent to the tip of the support pipe 12b. Further, the heat transfer member 18 has a shape that becomes thinner toward each of the plurality of other ends. By providing the heat transfer member 18, the frozen refrigerant 13 at the tip of the branch pipe 12b can be melted, and the electronic component 33 can be cooled even in a low temperature environment.

As described above, according to the cooling device 3 according to the fourth embodiment, by providing the heat transfer member 18 having a branch, the surface area of the heat transfer member 18 is increased, and the frozen refrigerant 13 is quickly melted. Is possible. As a result, the electronic component 33 can be cooled by the cooling device 3 even in a low temperature environment.

(Embodiment 5)
Another modification of the heat transfer member capable of quickly melting the frozen refrigerant 13 will be described in the fifth embodiment. The cooling device 4 according to the fifth embodiment shown in FIG. 10 includes a heat transfer member 19 that extends spirally as shown in FIGS. 10 and 11. The mechanism by which the cooling device 4 cools the electronic component 33 and the mechanism by which the cooling device 4 melts the frozen refrigerant 13 are the same as those of the cooling device 1.

The heat transfer member 19 is provided inside at least one of the heat pipes 12 and extends spirally in a direction away from the heat receiving block 11, specifically, in a direction away from the second main surface 11b. The heat transfer member 19 is made of a material having high thermal conductivity, for example, a metal such as copper or aluminum. Further, the value of the thermal conductivity of the heat transfer member 19 is preferably equal to or higher than the value of the thermal conductivity of the heat pipe 12. For example, the heat transfer member 19 may be made of the same material as the heat pipe 12.

One end of the heat transfer member 19 is adjacent to a part of the inner wall attached to the heat receiving block 11 of the heat pipe 12. Specifically, one end of the heat transfer member 19 is adjacent to the inner wall of the mother tube 12a. The other end of the heat transfer member 19 is located farther from the heat receiving block 11 than the fin 14. Then, the heat transfer member 19 transfers heat from one end to the other end. The other end of the heat transfer member 19 is preferably adjacent to the tip far from the heat receiving block 11 of the heat pipe 12, that is, adjacent to the inner wall of the tip of the branch pipe 12b. Specifically, it is preferable that the other end of the heat transfer member 19 is adjacent to the tip of the branch pipe 12b to such an extent that heat can be transferred to the refrigerant 13 frozen at the tip of the branch pipe 12b.

Further, it is preferable that the heat transfer member 19 is adjacent to the inner wall of the side surface of the branch pipe 12b. Specifically, the heat transfer member 19 is preferably adjacent to the inner wall of the side surface of the branch pipe 12b to such an extent that heat can be transferred to the frozen refrigerant 13 adhering to the inner wall of the side surface of the branch pipe 12b.

In the fifth embodiment, a heat transfer member 19 extending spirally is provided inside each branch pipe 12b, and one end of the heat transfer member 19 is welded and soldered to the inner wall of the mother pipe 12a to which the support pipe 12b is attached. It is fixed by etc. The other end of the heat transfer member 19 is located adjacent to the tip of the branch pipe 12b. By providing the heat transfer member 19, the refrigerant 13 frozen at the tip of the branch pipe 12b can be melted, and the electronic component 33 can be cooled even in a low temperature environment.

As described above, according to the cooling device 4 according to the fifth embodiment, by providing the heat transfer member 19 extending in a spiral shape, the frozen refrigerant 13 can be quickly melted. Further, as compared with the cooling device according to the first embodiment, since the heat transfer member 19 is located closer to the inner wall of the side surface of the branch pipe 12b, the frozen refrigerant 13 adhering to the inner wall of the side surface of the branch pipe 12b can be quickly melted. It will be possible. As a result, the electronic component 33 can be cooled by the cooling device 4 even in a low temperature environment.

(Embodiment 6)
Another modification of the heat transfer member capable of quickly melting the frozen refrigerant 13 will be described in the sixth embodiment. The cooling device 5 according to the sixth embodiment shown in FIG. 12 includes a heat transfer member 20 formed of a plate-shaped member having a curved surface. The mechanism by which the cooling device 5 cools the electronic component 33 and the mechanism by which the cooling device 5 melts the frozen refrigerant 13 are the same as those of the cooling device 1.

The heat transfer member 20 is provided inside at least one of the heat pipes 12 and extends in a direction away from the heat receiving block 11, specifically, in a direction away from the second main surface 11b. Specifically, the heat transfer member 20 has a curved surface along the inner wall of the heat pipe 12 at intervals, as shown in FIG. 13, which is a partial view of a cross-sectional view taken along the line CC in FIG. It is formed of a plate-shaped member. Specifically, the heat transfer member 20 has a shape obtained by dividing the cylinder into two by a surface including the central axis. The heat transfer member 20 is made of a material having high thermal conductivity, for example, a metal such as copper or aluminum. Further, the value of the thermal conductivity of the heat transfer member 20 is preferably equal to or higher than the value of the thermal conductivity of the heat pipe 12. For example, the heat transfer member 20 may be made of the same material as the heat pipe 12.

One end of the heat transfer member 20 is adjacent to a part of the inner wall attached to the heat receiving block 11 of the heat pipe 12. Specifically, one end of the heat transfer member 20 is adjacent to the inner wall of the mother tube 12a. The other end of the heat transfer member 20 is located farther from the heat receiving block 11 than the fin 14. Then, the heat transfer member 20 transfers heat from one end to the other end. The other end of the heat transfer member 20 is preferably adjacent to the tip far from the heat receiving block 11 of the heat pipe 12, that is, adjacent to the inner wall of the tip of the branch pipe 12b. Specifically, it is preferable that the other end of the heat transfer member 20 is adjacent to the tip of the branch pipe 12b to such an extent that heat can be transferred to the refrigerant 13 frozen at the tip of the branch pipe 12b.

Further, it is preferable that the curved surface of the heat transfer member 20 is adjacent to the inner wall of the side surface of the branch pipe 12b. Specifically, it is preferable that the curved surface of the heat transfer member 20 is adjacent to the inner wall of the side surface of the branch pipe 12b to such an extent that heat can be transferred to the frozen refrigerant 13 adhering to the inner wall of the side surface of the branch pipe 12b.

In the sixth embodiment, two heat transfer members 20 are provided inside each branch pipe 12b. The outer surface of each heat transfer member 20 is a curved surface, and is spaced along the inner wall of the side surface of the branch pipe 12b. One end of the heat transfer member 20 is fixed to the inner wall of the mother pipe 12a to which the support pipe 12b is attached by welding, soldering, or the like. The other end of the heat transfer member 20 is located adjacent to the tip of the branch pipe 12b. By providing the heat transfer member 20, the frozen refrigerant 13 at the tip of the branch pipe 12b can be melted, and the electronic component 33 can be cooled even in a low temperature environment.

As described above, according to the cooling device 5 according to the sixth embodiment, it is possible to quickly melt the frozen refrigerant 13 by providing the heat transfer member 20 formed of the plate-shaped member having a curved surface. Become. Further, since the heat transfer member 20 is located closer to the inner wall of the side surface of the branch pipe 12b as compared with the cooling device according to the first embodiment, the frozen refrigerant 13 adhering to the inner wall of the side surface of the branch pipe 12b can be quickly melted. It will be possible. As a result, the electronic component 33 can be cooled by the cooling device 5 even in a low temperature environment.

(Embodiment 7)
Another modification of the heat transfer member capable of quickly melting the frozen refrigerant 13 will be described in the seventh embodiment. The cooling device 6 according to the seventh embodiment shown in FIG. 14 includes a heat transfer member 21 formed of a flat plate-shaped member. The mechanism by which the cooling device 6 cools the electronic component 33 and the mechanism by which the cooling device 6 melts the frozen refrigerant 13 are the same as those of the cooling device 1.

The heat transfer member 21 is provided inside at least one of the heat pipes 12 and extends in a direction away from the heat receiving block 11, specifically, in a direction away from the second main surface 11b. Specifically, the heat transfer member 21 is formed of flat plate-shaped members located at intervals on the inner wall of the heat pipe 12. The heat transfer member 21 is made of a material having high thermal conductivity, for example, a metal such as copper or aluminum. Further, the value of the thermal conductivity of the heat transfer member 21 is preferably equal to or higher than the value of the thermal conductivity of the heat pipe 12. For example, the heat transfer member 21 may be made of the same material as the heat pipe 12.

One end of the heat transfer member 21 is adjacent to a part of the inner wall attached to the heat receiving block 11 of the heat pipe 12. Specifically, one end of the heat transfer member 21 is adjacent to the inner wall of the mother tube 12a. The other end of the heat transfer member 21 is located farther from the heat receiving block 11 than the fin 14. Then, the heat transfer member 21 transfers heat from one end to the other end. The other end of the heat transfer member 21 is preferably adjacent to the tip far from the heat receiving block 11 of the heat pipe 12, that is, the inner wall of the tip of the branch pipe 12b. Specifically, it is preferable that the other end of the heat transfer member 21 is adjacent to the tip of the support pipe 12b to such an extent that heat can be transferred to the refrigerant 13 frozen at the tip of the support pipe 12b.

In the seventh embodiment, the heat transfer member 21 is provided inside each branch pipe 12b. Each heat transfer member 21 includes two flat plate-shaped members extending in the extending direction and the Z-axis direction of the branch pipe 12b, and a flat plate-shaped member sandwiched between the two flat plate-shaped members and extending in the extending direction and the Y-axis direction of the branch pipe 12b. Have. As shown in FIG. 15, which is a partial view of a cross-sectional view taken along the line DD in FIG. 14, the shape of the heat transfer member 21 on the YZ plane has an H-shape. One end of the heat transfer member 21 is fixed to the inner wall of the mother pipe 12a to which the support pipe 12b is attached by welding, soldering, or the like. The other end of the heat transfer member 21 is located adjacent to the tip of the branch pipe 12b. By providing the heat transfer member 21 as described above, the refrigerant 13 frozen at the tip of the branch pipe 12b can be melted, and the electronic component 33 can be cooled even in a low temperature environment.

As described above, according to the cooling device 6 according to the seventh embodiment, by providing the heat transfer member 21 formed of the flat plate-shaped member, the frozen refrigerant 13 can be quickly melted. Further, as compared with the cooling device 1 according to the first embodiment, since the heat transfer member 21 is located closer to the inner wall of the side surface of the branch pipe 12b, the frozen refrigerant 13 adhering to the inner wall of the side surface of the branch pipe 12b is quickly melted. Is possible. As a result, the electronic component 33 can be cooled by the cooling device 6 even in a low temperature environment.

It is possible to combine each embodiment, and to appropriately modify or omit each embodiment.
As an example, a heat transfer member 15 may be provided in a part of the heat pipe 12 included in the cooling device 1, and at least one of the

heat transfer members

17, 18, 19, 20, and 21 may be provided in the other part. Further, it is not necessary to provide

heat transfer members

15, 17, 18, 19, 20, 21 in each heat pipe 12, and

heat transfer members

15, 17, 18, 19, 20, 21 are provided only in some heat pipes 12. Just do it.

The fixed positions and methods of the

heat transfer members

15, 17, 18, 19, 20, and 21 are not limited to the above examples, and any method can be used at a position where the heat-frozen refrigerant 13 transferred from the electronic component 33 can be melted. It can be fixed with. As an example, one end of the heat transfer member 22 included in the cooling device 7 shown in FIG. 16 is fixed to the lower end of the inner wall of the mother pipe 12a in the vertical direction. As another example, one end of the heat transfer member 23 included in the cooling device 8 shown in FIG. 17 is fixed to the inner wall of the mother pipe 12a, and the other end is fixed to the inner wall of the tip of the support pipe 12b. As another example, the

heat transfer members

15, 17, 18, 19, 20, 21, 22, 23 may be fixed to a heat insulating material having an arbitrary shape fixed to the branch pipe 12b.

The number and shape of the

heat transfer members

15, 17, 18, 19, 20, 21, 22, and 23 in each heat pipe 12 are the number and shape of the heat transferred from the electronic component 33 that can be transferred to the frozen refrigerant 13. Any shape is acceptable. As an example, as shown in FIG. 18, four heat transfer members 20 may be provided in the heat pipe 12. The heat transfer member 20 has a shape obtained by dividing a cylinder into four by two planes orthogonal to each other including the central axis of the cylinder. As another example, as shown in FIG. 19, the heat transfer member 21 may have flat plate-shaped

members

21a and 21b located at intervals from each other. The flat plate-shaped member 21a extends in the extending direction and the Y-axis direction of the branch pipe 12b. The two flat plate-shaped members 21b are located so as to sandwich the flat plate-shaped member 21a.

The shape of the heat receiving block 11 is not limited to the plate shape, and is arbitrary as long as the electronic component 33 can be fixed to the first main surface 11a and the heat pipe 12 can be fixed.

The structure and shape of the heat pipe 12 is arbitrary as long as it has a structure and shape capable of dissipating heat transferred from the electronic component 33. As an example, the cooling device 9 shown in FIG. 20 includes a heat pipe 24 having the shape of a bent pipe. As shown in FIG. 21, which is a cross-sectional view taken along the line EE of FIG. 20, a heat transfer member 25 having a bent rod-like shape is provided inside the heat pipe 24.

As another example, the cooling device 10 shown in FIG. 22 includes a heat pipe 26 communicating with a groove 11d formed in the heat receiving block 11. One end of the heat pipe 26 is fixed to the heat receiving block 11. One end of the heat transfer member 15 is fixed to the inner wall of the groove 11d, and the other end is adjacent to the tip far from the heat receiving block 11 of the heat pipe 26.

The shape of the cross section orthogonal to the stretching direction of the heat pipe 12 is not limited to a circular shape, but may be a flat shape. Specifically, the shape of the cross section of the mother pipe 12a and the branch pipe 12b orthogonal to the extending direction is not limited to a circular shape, but may be a flat shape. The flat shape is a shape obtained by deforming a part of the width of the circle to be narrower than the original circle, and includes an ellipse, a streamlined shape, an oval, and the like. The oval means a shape in which the outer edges of circles having the same diameter are connected by a straight line.

The number of heat pipes 12 attached to the heat receiving block 11 is arbitrary. Similarly, the number of mother pipes 12a and the number of branch pipes 12b attached to each mother pipe 12a are arbitrary.
The number of fins 14 is not limited to the above example and is arbitrary.

As the electronic component 33, a switching element formed of a wide bandgap semiconductor may be attached to the heat receiving block 11. Wide bandgap semiconductors include, for example, silicon carbide, gallium nitride based materials, or diamond.

The present disclosure allows for various embodiments and modifications without departing from the broad spirit and scope of the present disclosure. Moreover, the above-described embodiment is for explaining this disclosure, and does not limit the scope of the present disclosure. That is, the scope of the present disclosure is indicated by the scope of claims, not by the embodiment. And various modifications made within the scope of the claims and within the equivalent meaning of disclosure are considered to be within the scope of this disclosure.

1,2,3,4,5,6,7,8,9,10 Cooling device, 11 Heat receiving block, 11a 1st main surface, 11b 2nd main surface, 11c, 11d groove, 12, 24, 26 heat pipe , 12a mother pipe, 12b branch pipe, 13 refrigerant, 14 fins, 15, 17, 18, 19, 20, 21, 22, 23, 25 heat transfer member, 16 heat insulating material, 16a fitting hole, 21a, 21b flat plate member , 30 power converter, 31a, 31b primary terminal, 32 power converter, 33 electronic parts, 33a, 33b, 33c, 33d, 33e, 33f switching element, 34 housing, 34a opening, 35 cover, 35a intake / exhaust port, FC1 filter capacitor, M1 electric motor.

Claims

The heat receiving block to which the heating element is attached and
At least one heat pipe that is partially attached to the heat receiving block, extends away from the heat receiving block, and is filled with a refrigerant.
At least one heat transfer member provided inside at least one of the heat pipes and extending in a direction away from the heat receiving block.
The fins attached to the outer surface of the heat pipe and
With
One end of the heat transfer member is adjacent to a part of the inner wall attached to the heat receiving block of the heat pipe.
The other end of the heat transfer member is located farther from the heat receiving block than the fins.
Cooling system.
The heat transfer member transfers heat from one end to the other end.
The cooling device according to claim 1.
The one end of the heat transfer member is fixed to a part of the inner wall attached to the heat receiving block of the heat pipe.
The cooling device according to claim 1 or 2.
The other end of the heat transfer member is adjacent to the inner wall of the tip far from the heat receiving block of the heat pipe.
The cooling device according to any one of claims 1 to 3.
The other end of the heat transfer member is attached to the inner wall of the tip of the heat pipe.
The cooling device according to claim 4.
Further provided with a heat insulating material fixed to the inner wall of the tip of the heat pipe,
The other end of the heat transfer member is attached to the heat insulating material.
The cooling device according to claim 4.
The area of the cross section of the heat transfer member orthogonal to the stretching direction of one end is larger than the area of the cross section of the other end of the heat transfer member orthogonal to the stretching direction.
The cooling device according to any one of claims 1 to 6.
The heat transfer member has at least one branch and has a plurality of other ends located farther from the heat receiving block than the fins.
The cooling device according to any one of claims 1 to 7.
The heat transfer member has a rod-like shape.
The cooling device according to any one of claims 1 to 8.
The heat transfer member spirally extends in a direction away from the heat receiving block.
The cooling device according to any one of claims 1 to 8.
The heat transfer member is formed of a plate-shaped member having a curved surface along the inner wall of the heat pipe at intervals.
The cooling device according to any one of claims 1 to 8.
The heat transfer member is formed of flat plate-shaped members located at intervals on the inner wall of the heat pipe.
The cooling device according to any one of claims 1 to 8.
The heat transfer member is provided.
The cooling device according to any one of claims 1 to 12.
The value of the thermal conductivity of the heat transfer member is equal to or higher than the value of the thermal conductivity of the heat pipe.
The cooling device according to any one of claims 1 to 13.
Each of the at least one heat pipe
The mother tube fixed to the heat receiving block and
It has a plurality of branch pipes that are attached to the mother pipe, communicate with the mother pipe, and extend in a direction away from the heat receiving block.
The cooling device according to any one of claims 1 to 14.
A power conversion unit that converts the supplied electric power into electric power for supplying the load and supplies the converted electric power to the load.
The cooling device according to any one of claims 1 to 15 and the like.
The electronic component included in the power conversion unit is the heating element, which is attached to the heat receiving block included in the cooling device.
Power converter.