JP7430521B2 - Cooling devices and power conversion devices for mobile objects - Google Patents

Description

The present invention relates to a cooling device and a power conversion device for a moving body.

Self-excited vibration heat pipes generally have a narrow flow path with a diameter on the order of millimeters, and the working fluid is sealed in this narrow flow path in a state where liquid columns and air columns alternate due to surface tension. has been done. A plurality of heat receiving parts (high temperature parts) and heat radiation parts (low temperature parts) are provided alternately along the flow path, and the liquid is The column and the air column vibrate self-excited, thereby allowing heat to be transported between the heat receiving section and the heat radiating section.

Unlike general heat pipes, self-excited vibration heat pipes do not require circulation due to gravity, so they have the advantage of having a high degree of freedom in installation orientation. Furthermore, compared to general heat pipes, heat transfer performance can be maintained even if the diameter of the flow path is made smaller, so it has the advantage of being able to be made smaller.

Patent Document 1 includes a self-excited oscillating heat pipe that has a single-stroke meandering flow path inside a multi-hole flat tube and injects a working fluid from a working fluid injection capillary connected to an end of the flow path. A cooling device is disclosed. Further, Patent Document 2 and Patent Document 3 disclose the structure of a cooling device including a self-excited oscillating heat pipe.

Japanese Patent Application Publication No. 9-49692 Patent No. 4363501 Patent No. 4426684

The inventor of the present application has made the following findings as a result of intensive study on the problems encountered when mounting a cooling device equipped with a self-excited vibration heat pipe on a moving object such as a railway vehicle.

When a cooling device equipped with a self-excited vibrating heat pipe is mounted on a moving object such as a railway vehicle, the vibrations generated during running are relatively large, so countermeasures against the vibrations become an issue. For example, in a configuration in which a working fluid injection capillary is connected to an end of a flow path as in the self-excited vibration heat pipe described in Patent Document 1, there is a risk that the relatively weak working fluid injection capillary may be damaged by vibration. If this working fluid injection capillary is damaged, there is a concern that the working fluid in the flow path will leak to the outside and the performance of the self-oscillating heat pipe will deteriorate.

On the other hand, Patent Document 2 and Patent Document 3 do not disclose a hydraulic fluid injection thin tube. However, when installing a cooling device equipped with a self-excited vibration heat pipe on a moving object such as a railway vehicle, a simple structure with good productivity and a structure with excellent vibration resistance is required for the same reasons. .

Furthermore, according to the study results of the inventor of the present invention, in a self-oscillating heat pipe, the pressure of the working fluid sealed inside the flow path increases due to boiling or evaporation in the heat receiving section, and pressure decreases due to condensation in the heat dissipating section. Self-excited vibration occurs due to the pressure difference, but by creating a pressure imbalance in the flow path, creating a location where the amount of heat received or released is unbalanced compared to others, it improves the startability and cooling of the hydraulic fluid. It was found that performance improved.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cooling device and a power conversion device for a moving object, which have a simple structure with good productivity, improve strength reliability against vibration, and have good cooling performance.

In order to solve the above problems, one of the typical cooling devices for a moving body according to the present invention includes a sealed flow path that seals a working fluid inside and extends while turning back and forth alternately along the longitudinal direction. a self-excited oscillating heat pipe, and a heat receiving plate connected to the self-excited oscillating heat pipe and a heat generation source, and the self-exciting oscillating heat pipe has an end rising portion at at least one end. The height of the rising end portion is lower than the maximum height of the self-excited oscillating heat pipe, and the rising end portion of the self-exciting oscillating heat pipe includes an injection pipe for injecting a working fluid. This is achieved by providing a plurality of self-excited oscillating heat pipes, and communicating with each other via the injection pipe .

According to the present invention, it is possible to provide a cooling device and a power conversion device for a moving body that have a simple structure with good productivity, improve strength reliability against vibration, and have good cooling performance.
Problems, configurations, and effects other than those described above will be made clear by the following description of the embodiments.

FIG. 1 is a sectional view of a power conversion device mounted on a railway vehicle in Embodiment 1. FIG. 2 is a perspective view showing the cooling device in the first embodiment. FIG. 3 is a perspective view showing the cooling device in the first embodiment. FIG. 4 is a cross-sectional view taken along arrow A in FIG. 3, showing the flow path structure at the end of the self-excited vibrating heat pipe in the first embodiment. FIG. 5 is a sectional view taken along arrow B in FIG. 3, showing a part of the manufacturing process of the self-excited vibrating heat pipe in the first embodiment. FIG. 6 is a sectional view taken along arrow B in FIG. 3, showing the sealing structure of the end of the self-excited vibrating heat pipe in the first embodiment. FIG. 7 is a cross-sectional view taken along arrow B in FIG. 3, showing a sealing structure at the end of the self-excited vibrating heat pipe in Embodiment 2. FIG. 8 is a sectional view taken along arrow B in FIG. 3, showing a sealing structure at the end of the self-excited vibrating heat pipe in Embodiment 3. FIG. 9 is a sectional view taken along arrow B in FIG. 3, showing a sealing structure at the end of the self-excited oscillating heat pipe in Embodiment 4. FIG. 10 is a sectional view taken along arrow B in FIG. 3, showing a sealing structure at the end of the self-excited vibrating heat pipe in Embodiment 5. FIG. 11 is a cross-sectional view taken along arrow B in FIG. 3, showing a sealing structure at the end of the self-excited oscillating heat pipe in Embodiment 6. FIG. 12 is a perspective view showing a cooling device in Embodiment 7. FIG. 13 is a perspective view showing a cooling device in Embodiment 7. FIG. 14 is a cross-sectional view taken along arrow C in FIG. 12, showing a sealing structure at the end of the self-excited vibrating heat pipe in Embodiment 7. FIG. 15 is a cross-sectional view taken along arrow D in FIG. 12, showing a sealing structure at the end of the self-excited vibrating heat pipe in Embodiment 7. FIG. 16 is a cross-sectional view taken along the arrow E in FIG. 13, showing a sealing structure at the end of the self-oscillating heat pipe in Embodiment 7. FIG. 17 is a cross-sectional view taken along arrow F in FIG. 13, showing a sealing structure at the end of the self-oscillating heat pipe in Embodiment 7. FIG. 18 is a cross-sectional view taken along arrow E in FIG. 13, showing a sealing structure at the end of the self-excited oscillating heat pipe in Embodiment 8. FIG. 19 is a cross-sectional view taken along arrow C in FIG. 12, showing a sealing structure at the end of a self-excited vibrating heat pipe in Embodiment 9. FIG. 20 is a sectional view taken along arrow C in FIG. 12, showing a sealing structure at the end of the self-excited vibrating heat pipe in Embodiment 10. FIG. 21 is a perspective view showing the cooling device in the eleventh embodiment with the protective cover disassembled. FIG. 22 is a perspective view showing a cooling device with a protective cover attached in Embodiment 11. FIG. 23 is a sectional view of a power conversion device mounted on a railway vehicle in Embodiment 12. FIG. 24 is a cross-sectional view of a power conversion device mounted on a railway vehicle in Embodiment 13.

Embodiments of the present invention will be described below with reference to the drawings. Note that in this specification, "crushing" refers to pressing and deforming a material with a die or tool, and the deformed state remains. Moreover, "height" refers to the distance along the normal direction from the surface of the heat receiving plate to which the self-excited vibration heat pipe is attached. Moreover, the "maximum height of the self-excited oscillating heat pipe" refers to the height of the longest length from the heat receiving plate to the distal end among the rising parts of the self-excited oscillating heat pipe.

[Embodiment 1]
FIG. 1 is a cross-sectional view of a power conversion device mounted on a railway vehicle as a moving body in this embodiment. The power conversion device 1 is installed under the floor of the railway vehicle 2, and has a function of controlling the rotational speed of the electric motor by changing the frequency of the electric power supplied to the electric motor (not shown) that drives the railway vehicle 2. . Inside the power conversion device 1, a plurality of semiconductor elements 3 and an electrical component group 4 that constitute a power conversion circuit are installed. Heat loss occurs in the semiconductor element 3 during energization and ON/OFF switching, and the heat generated at this time is radiated and becomes a heat generation source. Since the characteristics of the semiconductor element 3 may deteriorate due to overheating or the product life may be shortened, a cooling device 5 is usually attached to cool the semiconductor element 3.

Running wind 8 generated when the railway vehicle 2 runs is supplied to the cooling device 5 in a direction perpendicular to the plane of the paper in FIG. 1, thereby radiating heat generated from the semiconductor element 3 and performing air cooling. Since the railway vehicle 2 moves in either the forward or backward direction, the traveling wind 8 is generated in the direction associated with the movement. The semiconductor element 3 is, for example, an IGBT (Insulated Gate Bipolar Transistor) or a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor).

The cooling device 5 will be explained. 2 and 3 are perspective views showing the cooling device 5 in this embodiment. The cooling device 5 includes a heat receiving plate 6, a self-excited vibration heat pipe 7, and a corrugated fin 9. The heat receiving plate 6, the self-excited vibration heat pipe 7, and the corrugated fin 9 are made of metal such as aluminum alloy or copper. A plurality of semiconductor elements 3 are fixed to one surface of the heat receiving plate 6 by screws or the like (not shown) via a member such as grease (not shown). A plurality of self-excited vibration heat pipes 7 are joined to the other surface of the heat receiving plate 6 by brazing or the like.

The self-excited vibration heat pipe 7 has an elongated multi-hole flat tube (flow path member), and in this embodiment, the multi-hole flat tube and the flow path are periodically bent and extended several times in the longitudinal direction. It is formed into a wave shape. The self-excited vibration heat pipe 7 has opposing surfaces when bent, and the corrugated fins 9 are joined by brazing or the like so as to connect these surfaces. Traveling wind 8 is supplied between the self-excited vibration heat pipe 7 and the corrugated fins 9, heat exchange is performed, and heat is radiated. With such a configuration, the self-excited oscillating heat pipe 7 is alternately provided with a heat receiving part that is a part that comes into contact with the heat receiving plate 6 and a heat radiating part that is a part that is in contact with the corrugated fins 9.
In addition, multiple straight multi-hole flat tubes (flow path members) with the same length are installed in parallel, and the working fluid is alternately supplied to the upper ends of adjacent multi-hole flat tubes via connecting pipes. By movably joining the lower ends of adjacent multi-hole flat tubes and movably joining the working fluid alternately, the pipes meander in a rectangular wave shape (alternately folded back and extended along the longitudinal direction). It is also possible to form a self-oscillating heat pipe with a closed channel. Such a self-excited vibration heat pipe has high production efficiency because it does not require a bending process for a multi-hole flat tube.

The internal structure of the self-excited vibration heat pipe 7 will be explained. FIG. 4 is a cross-sectional view taken along arrow A of a portion surrounded by a dotted line in FIG. 3, showing the flow path structure at the end of the self-excited vibrating heat pipe in this embodiment. Inside the self-excited vibration heat pipe 7, a plurality of channels 10 partitioned by partition walls 11 are arranged in parallel. The cross-sectional shape of each flow path 10 is rectangular or circular, the cross-sectional dimension of each flow path 10 and the thickness of the partition wall 11 are on the order of millimeters, and the length of each flow path 10 is sufficiently longer than the flow path diameter. An end sealing member 12 is joined to the end of the self-excited vibration heat pipe 7 . The end sealing member 12 is provided with a communication channel 13, and the channels 10 inside the self-excited vibration heat pipe 7 are communicated with each other through the communication channel 13.

A predetermined amount of working fluid (not shown) is sealed in the sealed flow path 10 of the multi-hole flat tube of the self-excited vibration heat pipe 7 . As the working fluid, for example, water, alcohols, hydrocarbons such as butane, hydrofluorocarbons, hydrofluoroethers, hydrofluoroolefins, perfluoroketones, etc. are used.

The sealing structure of the end of the self-excited vibration heat pipe 7 will be explained. FIG. 5 is a sectional view showing a part of the manufacturing process of the self-excited oscillating heat pipe in this embodiment, and FIG. 6 is a sectional view showing the sealing structure of the end of the self-exciting oscillating heat pipe. It is a sectional view taken along arrow B of a portion surrounded by a broken line. The end of the self-excited oscillating heat pipe 7 is raised vertically from the surface of the heat receiving plate 6 to a position lower than the maximum height of the self-excited oscillating heat pipe 7 (the rising portion 15 other than the end rising portion 14). In other words, it extends until it is spaced a predetermined distance from the surface of the heat receiving plate 6). Hereinafter, this raised portion will be referred to as an end raised portion 14. Note that the end rising portion 14 is not necessarily perpendicular to the surface of the heat receiving plate 6, and may be inclined.
The end rising portion 14 is connected to the rising portion 15 adjacent to the end rising portion 14 by a fixing member 19 . The fixing member 19, like the heat receiving plate 6, self-excited vibration heat pipe 7, and corrugated fin 9, is made of a thermally conductive metal such as aluminum alloy, copper, or resin. By making the fixing member 19 made of metal, heat dissipation and thermal conductivity are ensured, and heat transportability is enhanced. On the other hand, if the fixing member 19 is made of resin, the end rising portion 14 can be easily fixed.
Further, the end sealing member 12 joined to the end rising portion 14 is provided with an injection pipe 16 used for injecting the hydraulic fluid. The injection tube 16 is arranged to face perpendicularly (ie horizontally) to the end riser 14 .

During manufacturing, after a predetermined amount of working fluid is injected from the injection tube 16, the injection tube 16 is pinched from above and below by the crushing tool 17 and pressurized. As a result, as shown in FIG. 6, the injection tube 16 is crushed and plastically deformed, and a crushed sealing portion 18 is formed and hermetically sealed. At this time, it is desirable that the injection pipe 16 and the crushing sealing part 18 be arranged within a projection plane (referred to as a projection plane of the heat receiving plate 6) when the heat receiving plate 6 is projected along the normal direction.

The effects of the first embodiment will be explained. By raising the end of the self-excited vibration heat pipe 7 vertically to a position lower than the rising portion 15 other than the rising end portion 14, and joining the end sealing member 12 provided with the injection pipe 16, When crushing the injection tube 16, it becomes easier to pinch the injection tube 16 from above and below with the crushing tool 17, thereby improving productivity.

On the other hand, when the end of the self-excited vibrating heat pipe 7 is raised, the self-excited vibrating heat pipe 7, especially the cantilever-shaped end rising portion 14, is vibrated by the vibrations generated when the railway vehicle 2 runs. . According to the first embodiment, by connecting and reinforcing the end rising portion 14 and the adjacent rising portion 15 with the fixing member 19, the vibration of the end rising portion 14 is suppressed, and thereby the heat receiving plate 6 and the self-supporting portion 15 are connected and reinforced. The stress generated at the joint with the exciting vibration heat pipe 7 can be reduced, and the strength reliability against vibrations during running is improved.

Furthermore, by making the fixing member 19 of a thermally conductive material such as metal, heat is radiated from the fixing member 19 in the same way as the corrugated fins 9. Further, the height of the end rising portion 14 of the self-excited vibration heat pipe 7 is lower than the maximum height of the self-excited vibration heat pipe 7, that is, the height of the rising portion 15 other than the end portion, and the fixing member 19 is joined. The difference in surface area between the corrugated fins 9 and the fixing member 19 to be joined at the end portion and the portion other than the end portion causes an imbalance in heat dissipation ability. This makes it easier for pressure imbalance within the flow path 10 to occur, thereby improving the startability and cooling performance of the hydraulic fluid. The height of the end rising portion 14 is preferably 1/2 or less of the maximum height of the self-excited vibration heat pipe 7, and more preferably 1/3 or less.

Furthermore, if the end rising portion 14 is arranged higher than the rising portion 15 other than the end, or if the injection pipe 16 and the crushing sealing portion 18 are arranged so as to protrude outside the projection plane of the heat receiving plate 6. In this case, the outer shape of the cooling device 5 becomes irregular, which deteriorates handling properties, and when it is mounted on the railway vehicle 2, flying objects are likely to collide with the injection pipe 16 and the crush sealing portion 18. On the other hand, as in the first embodiment, by making the end rising portion 14 lower than the other rising portions 15 and arranging the injection pipe 16 and the crushing sealing portion 18 within the projection plane of the heat receiving plate 6, Handling efficiency is improved, and since flying objects that may cause damage are less likely to collide with the injection tube 16 and the crushing sealing portion 18, strength reliability is improved.

Furthermore, when the injection tube 16 is directly connected to the end of the self-excited vibrating heat pipe 7 in the direction along the flow path 10 as described in Patent Document 1, the self-excited vibrating heat pipe 7 Since the thickness is relatively thin, it is difficult to maintain the bonding strength with the injection tube 16 when used in applications where vibrations are relatively large. By joining the injection tube 16 via the end sealing member 12 as in Embodiment 1, the joint strength between the end sealing member 12 and the injection tube 16 can be maintained, and strength reliability is improved. .

Furthermore, the effects of hydraulic fluid will be explained. When applying a self-excited vibration heat pipe to a cooling device of a power conversion device for an electric railway vehicle, it is possible to use a refrigerant number R1336mzz (Z), which is a hydrofluoroolefin (hereinafter referred to as HFO), as the working fluid. desirable. The advantages of using refrigerant number R1336mzz (Z) will be described below.

(a) Since the critical temperature of refrigerant number R1336mzz (Z) is approximately 170°C, the heat transfer performance of the self-oscillating heat pipe 7 is maintained even when the power semiconductor module is used at temperatures up to approximately 170°C. can do.

(b) Since refrigerant number R1336mzz (Z) does not contain chlorine, it is chemically stable with respect to aluminum alloy, and when using aluminum alloy as the material for the self-excited vibration heat pipe 7, Heat transfer performance can be maintained for a long period of time without corroding the self-excited vibration heat pipe 7 from within.

(c) Refrigerant number R1336mzz (Z) is non-flammable and has low toxicity, so even if some of the flow paths are damaged due to a collision with a flying object and the working fluid is released into the atmosphere, safety is maintained. can be secured.

(d) Since the refrigerant number R1336mzz (Z) does not require the degassing step that is required with some other working fluids, the number of steps in manufacturing the self-excited oscillating heat pipe 7 can be reduced.

In addition, as a working fluid, instead of refrigerant number R1336mzz (Z), refrigerant number R1224yd (Z), R1234yf, R1234ze (E), R1123, R1234ze (Z), R1336mzz (E), R1233zd (Z) or R123 3zd(Z ) may also be used. HFOs have a low global warming potential and ozone layer depletion potential, so even if some flow paths are damaged by a collision with a flying object and the hydraulic fluid is released into the atmosphere, the impact on the environment will be reduced. be able to.

[Embodiment 2]
FIG. 7 is a sectional view taken along arrow B of a portion surrounded by a long broken line in FIG. 3, showing a sealing structure at the end of a self-excited oscillating heat pipe in Embodiment 2. As a difference from Embodiment 1, in this embodiment, the end sealing member 12 is connected to the rising portion 15 adjacent to the end rising portion 14 via the fixing member 19. Even in such a configuration, the same effects as in the first embodiment can be obtained. Furthermore, when the end sealing member 12 and the fixing member 19 are made of metal, heat dissipation can be ensured. Both the end sealing member 12 and the end rising portion 14 may be connected to the adjacent rising portion 15 via the fixing member 19.

[Embodiment 3]
FIG. 8 is a cross-sectional view taken along arrow B of a portion surrounded by a long broken line in FIG. 3, showing a sealing structure at the end of a self-excited vibrating heat pipe in Embodiment 3. As a difference from Embodiments 1 and 2, in this embodiment, the end sealing member 12 is directly joined to the rising portion 15 adjacent to the end rising portion 14 without using the fixing member 19 . Even in such a configuration, the same effects as in the first embodiment can be obtained. Further, when the end sealing member 12 is made of metal, heat dissipation can be ensured, and the vibration damping performance of the end rising portion 14 can be improved. Furthermore, since the fixing member 19 is not installed, the number of parts can be reduced and productivity can be improved.

[Embodiment 4]
FIG. 9 is a cross-sectional view taken along arrow B of a portion surrounded by a long broken line in FIG. 3, showing a sealing structure at the end of a self-excited oscillating heat pipe in Embodiment 4. The difference from Embodiments 1 to 3 is that in this embodiment, the injection pipe 16 is arranged to face in the same direction as the end rising portion 14, that is, in a direction perpendicular to the heat receiving plate 6. If the distance between the end rising portion 14 and the adjacent rising portion 15 is large enough to accommodate a crushing tool (not shown in FIG. 9), such a configuration can be realized, and the same configuration as in the first embodiment can be achieved. effect can be obtained. Furthermore, even when the outer dimensions of the heat receiving plate 6 are small, the end sealing member 12 can be easily installed within its projection plane.

[Embodiment 5]
FIG. 10 is a sectional view taken along arrow B of a portion surrounded by a long broken line in FIG. 3, showing a sealing structure at the end of a self-excited oscillating heat pipe in Embodiment 5. As a difference from Embodiments 1 to 4, in this embodiment, the tip of the end rising portion 14 is further bent by 90 degrees, and the end sealing member 12 is bonded to the tip. The end sealing member 12 and the end rising portion 14 in the vicinity thereof are connected to the heat receiving plate 6 via the fixing member 19 . Even in such a configuration, the same effects as in the first embodiment can be obtained. Further, since it is easy to approach the crushing tool 17 that pinches the injection pipe 16 from above and below, productivity is improved.

[Embodiment 6]
FIG. 11 is a cross-sectional view taken along arrow B of a portion surrounded by a long broken line in FIG. 3, showing a sealing structure at the end of a self-excited oscillating heat pipe in Embodiment 6. As a difference from Embodiment 5, in this embodiment, a crushed sealing portion 18 is formed by crushing the end of the self-excited vibration heat pipe 7, and hermetically sealed. The self-excited vibration heat pipe 7 in the vicinity of the crushing sealing part 18 is connected to the heat receiving plate 6 via a fixing member 19. Even in such a configuration, the same effects as in the first embodiment can be obtained. Furthermore, since the end sealing member 12 is not provided, the number of parts can be reduced and productivity can be improved.
In addition, if the tip of the crushing sealing part 18 is welded to form a welded part WD as shown by the dotted line, or by providing a resin cap CP to cover the crushing sealing part 18 as shown by the dashed line, etc. , the sealing performance of the crush sealing portion 18 is improved. The welding portion WD and the cap CP can be provided to cover the crushing sealing portion in embodiments other than this embodiment.

[Embodiment 7]
12 and 13 are perspective views showing a cooling device in Embodiment 7. The present embodiment has a configuration in which the number of self-excited vibration heat pipes 7 installed is reduced compared to the first to sixth embodiments.

Differences from Embodiments 1 to 6 will be explained. FIG. 14 is a sectional view taken along arrow C of a portion surrounded by a long broken line in FIG. 12, showing a sealing structure of one end of a self-excited vibrating heat pipe in Embodiment 7. Moreover, FIG. 15 is a cross-sectional view taken along arrow D of a portion surrounded by a dotted line in FIG. 12, showing the sealing structure of one end of the self-excited vibration heat pipe in Embodiment 7. In this embodiment, the injection pipe 16 is directly joined to the end rising portion 14 of the self-excited vibration heat pipe 7 in the direction along the end surface. The injection pipe 16 is joined to connect the two self-excited oscillating heat pipes 7 as shown in FIG. 15, and forms a communication channel 13 that connects the two self-excited oscillating heat pipes 7 to each other. The injection pipe 16 faces in a direction perpendicular to the direction in which the flow channels 10 are lined up, that is, the rising direction. After a predetermined amount of hydraulic fluid is injected into the injection tube 16, it is crushed to form a crushed sealing portion 18 and hermetically sealed. In applications where vibration is relatively small, the injection tube 16 can be directly joined to the end rising portion 14 without providing the end sealing member 12 as in the above embodiment.

The structure of the other end of the self-excited vibration heat pipe 7 of Embodiment 7 will be explained. FIG. 16 is a cross-sectional view taken along arrow E of a portion surrounded by a long broken line in FIG. 13, showing the sealing structure of the other end of the self-excited vibration heat pipe in Embodiment 7. Further, FIG. 17 is a cross-sectional view taken along arrow F of a portion surrounded by a dotted line in FIG. 13, showing the sealing structure of the other end of the self-excited vibration heat pipe in Embodiment 7. An end sealing structure 12' having no injection tube is joined to the tip of the end rising portion 14 at the other end of the self-excited vibration heat pipe 7. A communication passage 13 is provided in the end sealing structure 12 ′, and the passage 10 inside each self-excited vibration heat pipe 7 is communicated with the communication passage 13 . Here, a partition is provided in the communication flow path 13 of the single end sealing structure 12', and the flow path 10 of one self-excited oscillating heat pipe 7 and the flow path 10 of the other self-excited oscillating heat pipe 7 are separated. are made so that they do not communicate with each other. However, the partition of the communication channel 13 may be omitted.

Even with the configuration of this embodiment, the same effects as in Embodiment 1 can be obtained. Furthermore, in the case where the partition of the communication flow path 13 is omitted in the end sealing structure 12' and the communication flow path 13 that communicates the self-excited vibration heat pipes 7 with each other is formed, a plurality of self-excitation vibration heat pipes can be connected from the opposite end side. Since the working fluid can be injected into the vibrating heat pipe 7 at once, productivity is improved. Note that end sealing members 12 having injection pipes may be provided at both ends of the self-excited vibration heat pipe 7.

[Embodiment 8]
FIG. 18 is a sectional view taken along arrow D of a portion surrounded by a dotted line in FIG. 12, showing a sealing structure for the end of a self-excited vibrating heat pipe in Embodiment 8. As a difference from Embodiment 7, in this embodiment, one injection tube 16 is joined to each self-excited vibration heat pipe 7, and each injection tube 16 is individually sealed by crushing. When a plurality of self-excited vibrating heat pipes 7 are connected so as to be able to communicate with each other by injection pipes 16 or the like, if a flying object or the like collides with one self-excited vibrating heat pipe 7 and the flow path is damaged, other self-excited vibrating heat pipes 7 Since the working fluid also leaks from the excitation vibration heat pipe 7, the cooling performance deteriorates significantly. On the other hand, by configuring one injection pipe 16 to be joined to each self-excited vibration heat pipe 7 and each to be sealed independently, it is possible to suppress deterioration of cooling performance in the event of breakage.
Note that even in the configuration in which the end sealing member described above is provided, the configuration can be similar to that shown in FIGS. 15, 17, and 18.

[Embodiment 9]
FIG. 19 is a cross-sectional view taken along arrow C of a portion surrounded by a long broken line in FIG. 12, showing a sealing structure at the end of a self-excited oscillating heat pipe in Embodiment 9. As a difference from the seventh embodiment, the rising height of the end rising portion 14 of the self-excited oscillating heat pipe 7 is made as small as possible, and the fixing member 19 is not provided, and the end portion 14 of the self-excited oscillating heat pipe 7 is Injection tube 16 is directly joined. Because the rising height of the end rising portion 14 is low, it is difficult to be vibrated, and therefore, if the stress generated at the joint between the heat receiving plate 6 and the self-excited vibration heat pipe 7 does not become large enough to damage the joint, it is fixed. By not installing any parts, the number of parts can be reduced, which improves productivity.

[Embodiment 10]
FIG. 20 is a cross-sectional view taken along arrow C of a portion surrounded by a long broken line in FIG. 12, showing the sealing structure of the end of the self-excited oscillating heat pipe in Embodiment 10. In this embodiment, as in Embodiment 5, the tip of the end rising portion 14 of the self-excited vibration heat pipe 7 is further bent by 90 degrees, and the injection pipe 16 is directly joined in the direction along the end surface of the self-excited vibration heat pipe 7. The end rising portion 14 and the heat receiving plate 6 are connected via the end portion 19 . Even in such a configuration, the same effects as in the first embodiment can be obtained. The injection pipe 16 and the heat receiving plate 6 may be connected via the fixing member 19.

[Embodiment 11]
FIG. 21 is a perspective view showing the cooling device in the eleventh embodiment with the protective cover disassembled. Further, FIG. 22 is a perspective view showing a cooling device with a protective cover attached in Embodiment 11. The cooling device 5 of this embodiment includes a housing-shaped protective cover 20 that covers the entire self-excited vibration heat pipe 7 and is attached to the heat receiving plate 6. The protective cover 20 is provided with a plurality of ventilation holes 21 having a predetermined size so as to face the self-excited vibration heat pipe 7 in the direction of flow of running wind (the direction in which the railway vehicle travels). Running wind 8 generated when the railway vehicle 2 runs passes through the ventilation holes 21 and is supplied to the self-excited vibration heat pipe 7 and the corrugated fins 9.

By providing the protective cover 20 in this way, it is possible to suppress the collision of flying objects to the self-excited vibrating heat pipe 7, and the reliability of the self-excited vibrating heat pipe 7 is improved. Furthermore, by providing the ventilation holes 21 with appropriate dimensions, it is possible to achieve both the strength of the protective cover 20 against flying objects and the ventilation of the running wind 8.

Further, the protective cover 20 shown in FIG. 22 is provided with ventilation holes 21 facing also in the vertical direction (direction perpendicular to the traveling wind). With such a configuration, when the railway vehicle 2 runs and the temperature of the cooling device 5 rises, and then stops, natural convection moves from the ventilation hole 21 on the bottom surface of the protective cover 20 to the ventilation hole 21 on the top surface. Air flow is promoted. Due to this effect, the temperature of the cooling device 5 becomes lower before the railway vehicle 2 resumes running, so that the maximum temperature reached during running can be lowered.

On the other hand, in the protective cover 20 shown in FIG. 22, the ventilation holes 21 are not provided on the surface 22 on the opposite side (opposing side) to the side in contact with the heat receiving plate 6. Since this surface 22 is perpendicular to the flow direction of the traveling wind 8 and natural convection, it is preferable to prioritize strength against flying objects over the intake amount of cooling air when mounted on the railway vehicle 2. Reliability can be improved without compromising cooling performance. Further, by not providing an opening such as a ventilation hole 21 on this surface 22, it is possible to prevent sunlight from directly irradiating the cooling device 5 and to reduce the temperature rise of the cooling device 5 during clear weather.

[Embodiment 12]
FIG. 23 is a sectional view of a power conversion device mounted on a railway vehicle in Embodiment 12. In the first embodiment, the cooling device 5 is arranged horizontally with respect to the semiconductor element 3 which is a heat generation source, whereas in this embodiment, the cooling device 5 is arranged vertically downward with respect to the semiconductor element 3 which is a heat generation source. A self-excited vibration heat pipe 7 is arranged to protrude from the bottom surface of the power conversion device 1, and heat is radiated by the running wind 8. Since the working fluid in the self-excited vibration heat pipe 7 operates due to the pressure difference in the flow path, unlike general heat pipes, it does not require return flow due to gravity, so the cooling performance is less affected by the installation orientation. . If there are severe dimensional constraints on the side surface of the power converter 1 and there is no space to install the cooling device 5, cooling performance can be maintained even if the cooling device 5 is placed on the bottom of the power converter 1 as in this embodiment. can do.

[Embodiment 13]
FIG. 24 is a cross-sectional view of a power conversion device mounted on a railway vehicle in Embodiment 13. In this embodiment, the cooling device 5 is installed inside the power conversion device 1, and the cooling device 5 is arranged vertically upward with respect to the semiconductor element 3, which is a heat generation source. Cooling air 24 is supplied by the blower 23 to the self-excited vibration heat pipe 7 to radiate heat, and the cooling air 24 that has received the heat is exhausted from the side of the power converter 1 . If there are severe dimensional constraints on the side and bottom surfaces of the power converter 1 and there is no space in which to install the cooling device 5, the cooling performance may be reduced even if the cooling device 5 is placed inside the power converter 1 as in this embodiment. can be maintained.

Note that the present invention is not limited to the embodiments described above, and includes various modifications. For example, the embodiments described above are described in detail to explain the present invention in an easy-to-understand manner, and the present invention is not necessarily limited to having all the configurations described. Further, it is possible to replace a part of the configuration in one embodiment with the configuration in another embodiment, and it is also possible to add the configuration in another embodiment to the configuration in one embodiment. . Furthermore, it is also possible to add, delete, or replace some of the configurations in each embodiment with other configurations. For example, the present invention is applicable not only to railway vehicles but also to cooling devices for moving bodies such as automobiles, aircraft, and ships.

1: Power conversion device 2: Railway vehicle 3: Semiconductor element 4: Electrical component group 5: Cooling device 6: Heat receiving plate 7: Self-excited vibration heat pipe 8: Traveling wind 9: Corrugate fin 10: Channel 11: Partition wall 12: End sealing member 13: Communication channel 14: End rising portion 15 of self-excited vibration heat pipe 7: Standing portion 16 adjacent to end rising portion 14: Injection pipe 17: Crushing tool 18: Crushing sealing portion 19 : Fixed member 20: Protective cover 21: Ventilation hole 22: Surface of the protective cover opposite to the side that is in contact with the heat receiving plate 6 (opposite side) 23: Blower 24: Cooling air

Claims (12)

A self-excited oscillating heat pipe having a sealed flow path that encloses a working fluid inside and extends while turning back and forth alternately along the longitudinal direction, and a heat receiving plate connected to the self-excited oscillating heat pipe and a heat generation source. death,
The self-excited oscillating heat pipe has an end rising portion at at least one end, and the height of the end rising portion is lower than the maximum height of the self-exciting oscillating heat pipe,
An injection pipe for injecting a working fluid is connected to a rising end portion of the self-excited vibration heat pipe,
A plurality of the self-excited oscillating heat pipes are provided, and the plurality of self-exciting oscillating heat pipes communicate with each other via the injection pipe.
A cooling device for a moving object, which is characterized by: The cooling device for a moving body according to claim 1,
A cooling device for a moving body, wherein the end rising portion is fixed to the rising portion of the self-excited oscillating heat pipe or the heat receiving plate via a fixing member. The cooling device for a moving body according to claim 2,
A cooling device for a moving object, wherein the fixing member is made of metal or resin. The cooling device for a moving body according to any one of claims 1 to 3 ,
A cooling device for a moving body, characterized in that the injection pipe is installed so as to face perpendicularly to the rising direction of the self-excited vibration heat pipe. The cooling device for a moving body according to any one of claims 1 to 4 ,
A cooling device for a moving body, characterized in that the injection pipe is sealed by crushing. The cooling device for a moving body according to claim 5 ,
A cooling device for a moving body, characterized in that after the injection pipe is sealed by crushing, the crushing sealing part is covered by welding or resin. The cooling device for a moving body according to any one of claims 1 to 6 ,
A cooling device for a moving body, characterized in that the injection pipe is arranged within a projection plane of the heat receiving plate. The cooling device for a moving body according to any one of claims 1 to 7 ,
A cooling device for a moving body, comprising a protective cover provided with ventilation holes in the direction of flow of cooling air for the self-excited oscillating heat pipe. The cooling device for a moving body according to claim 8 ,
A cooling device for a moving body, characterized in that the protective cover is provided with ventilation holes on an upper surface and a lower surface in a vertical direction relative to the self-excited vibration heat pipe. The cooling device for a moving body according to any one of claims 1 to 9 ,
A cooling device for a mobile object, wherein the working fluid is a hydrofluoroolefin. A cooling device for a moving body according to any one of claims 1 to 10 ,
A power conversion device comprising: a power conversion circuit including a semiconductor element that is the heat generation source. The power conversion device according to claim 11 ,
A power conversion device comprising: a blower device that supplies cooling air to the self-excited oscillating heat pipe of the cooling device.

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