Railway vehicle power converter

A power converter for a railway vehicle includes a power converter body configured to be installed on the railway vehicle; a first radiating fin unit arranged on a front side on the power converter body for dissipating heat from the power converter body; a second radiating fin unit arranged on the power converter body on a rear side for dissipating heat from the power converter body; and an air duct that takes in air from a region other than regions in which the first and second radiating fin units are disposed while the railway vehicle is moving, the air duct extending into a fin separation space that is defined as a space between the first radiating fin unit and the second radiating fin unit so as to guide air that is taken in into the fin separation space.

BACKGROUND OF THE INVENTION

Technical Field

The present invention relates to a railway vehicle power converter, and more particularly to a railway vehicle power converter that includes a plurality of radiating fins for dissipating heat from components of a railway vehicle while the railway vehicle is moving.

Background Art

Railway vehicle power converters that include a plurality of radiating fins for dissipating heat from components of a railway vehicle while the railway vehicle is moving are a well-known technology (see Patent Document 1, for example).

Patent Document 1 discloses a railway vehicle semiconductor heat sink device that includes a plurality of heat sinks (radiating fins) used in a vehicle-driving power converter that is mounted under the floor of a railway vehicle. In the railway vehicle semiconductor heat sink device disclosed in Patent Document 1, in a space under the floor of the vehicle, the heat sinks (radiating fins) are arranged in lines in the horizontal direction on the side faces of the power converter and divided into three groups in the vehicle movement direction. Moreover, the outer sides of these heat sink groups are covered by a protective cover in which a large number of air holes are formed. Inside the protective cover, air-guiding plates are formed slanting towards each side of the heat sinks. In this way, the airflow created while the vehicle is moving is taken in through the air holes in the protective cover and then directly or partially flows along the air-guiding plates and is supplied to the heat sinks (radiating fins).

RELATED ART DOCUMENT

Patent Document

SUMMARY OF THE INVENTION

However, in the railway vehicle semiconductor heat sink device disclosed in Patent Document 1, although the airflow is taken in through the large number of air holes in the protective cover and is then supplied to the individual heat sinks (radiating fins) by the air-guiding plates, the complex flow pattern inside of the protective cover resulting from the relative positioning of the individual heat sinks and the locations at which the air-guiding plates are attached can potentially result in situations in which not all of the airflow that enters the protective cover is supplied to the heat sinks. Moreover, when some of the air that enters the protective cover simply passes through and is exhausted through the large number of air holes in the protective cover to back outside of the protective cover without being used for heat exchange with the heat sinks, the airflow supplied (guided) to the individual heat sinks becomes insufficient, and it is not possible to maximize the heat dissipation performance of the heat sinks. This results in a decrease in the overall heat dissipation performance of the heat sinks.

The present invention was made to solve the abovementioned problems, and one object of the present invention is to provide a railway vehicle power converter that makes it possible to improve the overall heat sink performance (heat dissipation performance) of a heat sink unit that includes a plurality of radiating fins. Accordingly, the present invention is directed to a scheme that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, in one aspect, the present disclosure provides a power converter for a railway vehicle, including: a power converter body configured to be installed on the railway vehicle; a first radiating fin unit arranged on a front side with respect to a movement direction of the railway vehicle on the power converter body, the first radiating fin unit having a plurality of fins each extending in the movement direction and dissipating heat from the power converter body; a second radiating fin unit arranged on the power converter body on a rear side, separated from the first radiating fin unit by a prescribed distance, the second radiating fin unit having a plurality of fins each extending in the movement direction and dissipating heat from the power converter body; and an air duct that takes in air from a region other than regions in which the first and second radiating fin units are disposed while the railway vehicle is moving, the air duct extending into a fin separation space that is defined as a space between the first radiating fin unit and the second radiating fin unit so as to guide air that is taken in into the fin separation space.

As described above, the railway vehicle power converter according to this aspect of the present invention includes the air duct that takes in air from a region outside the first radiating fins and the second radiating fins while the railway vehicle is moving and extends into the fin separation region between the first radiating fins and the second radiating fins so as to guide air that is taken in into the fin separation region. In this way, when the railway vehicle is traveling with the first radiating fins on the forward side (the upstream side), for example, the airflow (fresh outside air) taken in from the region outside the first radiating fins and the second radiating fins can be brought through the air duct and reliably guided into the fin separation region between the first radiating fins and the second radiating fins. Furthermore, the air (airflow) that is guided into the fin separation region can be reliably (and sufficiently) supplied to the rearward (downstream) second radiating fins, thereby making it possible to maintain the heat dissipation performance of the second radiating fins at the same level as the heat dissipation performance of the upstream first radiating fins. This makes it possible to maximize the heat dissipation performance of the individual radiating fins (the first radiating fins and the second radiating fins), thereby making it possible to improve the overall heat sink performance (heat dissipation performance) of a heat sink unit of the railway vehicle.

In the railway vehicle power converter according to the aspect described above, it is preferable that the first radiating fin unit and the second radiating fin unit each include a base fixed to a surface of the power converter body, the base supporting and attaching edges of the respective plurality of fins, and that the air duct include, in the fin separation space, a duct that has an elongated shape with a height lower than or equal to a height of the respective bases, the duct having an opening that creates an outlet in a surface of the duct so as to exhaust air in the duct outwardly into the fin separation space. Here, because the protrusion height of the duct is less than or equal to the protrusion height of the bases, the duct does not protrude out between the plurality of fins of the first radiating fins and the plurality of fins of the second radiating fins in the fin separation region, thereby making it possible to easily allocate a passage (space) for the air in the fin separation region. Therefore, the airflow (fresh outside air) exhausted from the outlet is diffused downwards into the fin separation region and can be effectively supplied to the fins (of the first radiating fins or the second radiating fins) that are currently rearward (downstream) according to the movement direction of the railway vehicle.

In the configuration described above in which the air duct includes the duct and the outlet, it is preferable that the duct be attached to a portion of the surface of the power converter body to which the respective bases are fixed. This makes it possible to easily arrange the duct that has a protrusion height of less than or equal to the protrusion height of the bases so as to extend along the surface of the main power converter unit and into the fin separation region.

In the configuration described above in which the air duct includes the duct and the outlet, it is preferable that, in the fin separation space, the duct extend in a direction that is orthogonal to the movement direction. This makes it possible to guide the airflow (fresh outside air) that is taken in from the region outside the first radiating fins and the second radiating fins through the duct and into the fin separation region across a wide region (range) that extends from the end sides to the center side in the direction that is orthogonal to the movement direction.

In the configuration described above in which the air duct includes the duct and the outlet, it is preferable that the outlet in the duct substantially span from one end of the fin separation space to another end of the fin separation space in a direction that is orthogonal to the movement direction and that is parallel to the surface of the power converter body to which the respective bases are fixed. This makes it possible to exhaust the airflow (fresh outside air) that is taken in from the region outside the first radiating fins and the second radiating fins through the outlet and into the fin separation region across a wide range that spans from near the one side to near the other side in the direction that is orthogonal to the movement direction. Therefore, the airflow that is diffused into the fin separation region can be uniformly supplied along the direction that is orthogonal to the movement direction to the fins (of the first radiating fins or the second radiating fins), depending on which are currently rearward (downstream) according to the movement direction of the railway vehicle.

In the configuration described above in which the air duct includes the duct and the outlet, it is preferable that the outlet be slit-shaped and extend in a direction in which the duct extends. This makes it possible to exhaust the airflow that is taken in from the region outside the first radiating fins and the second radiating fins through the slit-shaped outlet and into the fin separation region in an air curtain-shaped flow pattern. Therefore, this air curtain-shaped airflow can be uniformly supplied along the direction that is orthogonal to the movement direction from near the one side to near the other side of the fins that are currently rearward (downstream) according to the movement direction of the railway vehicle.

In the configuration described above in which the air duct includes the duct and the outlet, it is preferable that the outlet be formed of a plurality of slits that are arranged in a direction in which the duct extends and that are separated from one another by a prescribed interval. This makes it possible to adjust parameters such as the number and positioning of the outlets in accordance with the length of the duct that extends through the fin separation region, thereby making it possible to shape the flow pattern of the airflow that is exhausted into the fin separation region from the outlets to have a desired shape.

It is preferable that the configuration described above in which the air duct includes the duct and the outlet further include an air-guiding plate configured so as to guide air that is exhausted through the outlet into the fin separation space towards a lateral end of the first radiating fin unit or the second radiating fin unit that is adjacent to the outlet. This makes it possible to use the first air-guiding plate to efficiently and reliably guide the airflow (fresh outside air) to the movement direction-side ends of the fins that are currently rearward (downstream) according to the movement direction of the railway vehicle.

In the configuration described above in which the air duct includes the duct and the outlet, it is preferable that the air duct further include an inlet that takes in air from a space that is located outside of the fin separation space, and that air that enters the inlet be guided into the duct, travel through the duct, and then be exhausted through the outlet outwardly into the fin separation space in a direction in which the respective plurality of fins extend from the respective bases. This makes it possible to easily take in, via the inlet, the airflow flowing along the region of the railway vehicle on the outer side of the fins (of the first radiating fins or the second radiating fins) in the direction that is orthogonal to the movement direction and also makes it possible to guide that air through the duct-shaped duct that is connected to the inlet and then collect that air in the fin separation region. Then, that air can be reliably supplied to the rearward (downstream) fins (of the first radiating fins or the second radiating fins) through the outlet that forms an opening into the fin separation region.

In this case, it is preferable that the air duct include two of the inlet that are a first inlet and a second inlet, the first inlet being configured to take in an airflow when the railway vehicle is traveling in the movement direction with the first radiating fin unit placed on the front side relative to the second radiating fin unit, the second inlet being configured to take in an airflow when the railway vehicle is traveling in a reversed direction opposite to the movement direction with the second radiating fin unit placed on a front side relative to the reversed direction, and that the air duct further include an air-guiding plate or plates configured to guide air taken in by the first inlet or the second inlet, depending on a movement direction of the railway vehicle, into the duct. In this way, the airflow that is taken in through the first inlets or the second inlets (depending on the movement direction of the railway vehicle) can be reliably supplied from the fin separation region to the rearward (downstream) fins (of the first radiating fins or the second radiating fins).

In the railway vehicle power converter according to the aspect described above, it is preferable that the air duct be formed spanning from an outer space that is located outside the fin separation space on one side of the fin separation space in a direction orthogonal to the movement direction to another outer space that is outside of the fin separation space on an opposite side. This makes it possible to reliably take in the airflow (fresh outside air) from at least one of the region on one side of the first radiating fins and the second radiating fins or the region on the other side that are positioned further outward than the fin separation region in the direction that is orthogonal to the movement direction and to then reliably guide that air into the fin separation region. Therefore, the overall heat sink performance (heat dissipation performance) of a heat sink unit of the railway vehicle can be maintained at a prescribed level without being significantly affected by the traveling conditions of the railway vehicle or the strength of the resulting airflow.

In this case, it is preferable that the air duct have inlets on respective sides of the fin separation space, respectively opening to the outer space and the another outer space so as to take in air from the outer space and the another outer space, respectively. This makes it possible to reliably prevent air that passes through and is heated by the first radiating fins or the second radiating fins while the railway vehicle is moving from being taken in again via the inlets of the air duct.

In the configuration described above in which the air duct further includes the inlets, it is preferable that the inlets be provided on respective surfaces of the power converter body that are located outside of the fin separation space; that the first radiating fin unit and the second radiating fin unit each include a base fixed to a surface of the power converter body, the base supporting edges of the respective plurality of fins; that air duct include, in the fin separation space, a duct that has an elongated shape with a height lower than or equal to a height of the respective bases; and that air that flows along the respective surfaces of the power converter body while the railway vehicle is moving be taken in via the respective inlets, and air that is taken in via the inlets be guided into the duct. This makes it possible to effectively take in the airflow (fresh outside air) that flows along the surfaces on both sides of the main power converter unit that are positioned further outwards than the fin separation region and to then effectively supply that air to the fins (of the first radiating fins or the second radiating fins) that are currently rearward (downstream) according to the movement direction of the railway vehicle.

In this case, it is preferable that lengths of the inlets along directions parallel to the respective surfaces on which the inlets are provided be greater than the height of the duct. This makes it possible to increase the opening area of the inlets, thereby making it possible to temporarily collect more of the airflow (fresh outside air) that was taken in within the duct and then vigorously exhaust the air collected in the duct into the fin separation region.

In the railway vehicle power converter according to the aspect described above, it is preferable that the air duct have a shape that is line-symmetric about a center line running through the fin separation space in a direction that is orthogonal to the movement direction. This makes it possible to reduce variation between the amounts of heat dissipated by the first radiating fins and the second radiating fins regardless of whether the railway vehicle is traveling with the first radiating fin side or the second radiating fin side in the forward direction. In other words, this makes it possible to sufficiently improve the heat sink performance of the present invention regardless of the movement direction of the railway vehicle.

In the railway vehicle power converter according to the aspect described above, it is preferable that the air duct have a shape that is line-symmetric about a center line parallel to the movement direction. This makes it possible to uniformly take in the airflow (fresh outside air) from the region positioned further outwards than the fin separation region on one side in the direction that is orthogonal to the movement direction and from the region positioned further outwards than the fin separation region on the other side and to then guide that air into the fin separation region. Therefore, the overall heat sink performance (heat dissipation performance) of a heat sink unit of the railway vehicle can be maintained at a prescribed level without being significantly affected by the traveling conditions of the railway vehicle or the strength of the resulting airflow.

In the configuration described above in which the air duct includes the duct and the outlet, it is preferable that, in the fin separation space, the duct be configured to extend in a railway tie direction that is orthogonal to the movement direction. Here, when the plurality of fins of the first radiating fins and the second radiating fins are formed extending in the vertical direction of the railway vehicle, the airflow (fresh outside air) exhausted from the outlet can be diffused into the fin separation region and can then be effectively supplied to the fins (of the first radiating fins or the second radiating fins) that are currently rearward (downstream) according to the movement direction of the railway vehicle.

In this case, it is preferable that the power converter body be configured to be mounted in an underfloor space of the railway vehicle; that the surface of the power converter body to which the first radiating fin unit and the second radiating fin unit are attached be a bottom surface of the power converter body; that the air duct be attached along the bottom surface of the power converter body to which the first radiating fin unit and the second radiating fin unit are fixed; and that the air duct be configured to guide air that is taken in from a position near the bottom surface of the power converter body or from a position further away than the position near the bottom surface while the railway vehicle is moving into the fin separation space and to then exhaust the air towards a lateral end of the first radiating fin unit or the second radiating fin unit. Here, when there is sufficient space to mount the first radiating fins and the second radiating fins beneath the main power converter unit, the first radiating fins and the second radiating fins can easily be mounted in a way that makes it possible to effectively equalize the heat sink performance (heat dissipation performance) of the first radiating fins and the second radiating fins when dissipating heat from the main power converter unit.

In the configuration described above in which the air duct includes the duct and the outlet, it is preferable that, in the fin separation space, the duct be configured to extend in a vertical direction of the railway vehicle that is orthogonal to the movement direction. Here, when the plurality of fins of the first radiating fins and the second radiating fins are formed extending in the side direction of the railway vehicle, the airflow (fresh outside air) exhausted from the outlet can be diffused into the fin separation region and can then be effectively supplied to the fins (of the first radiating fins or the second radiating fins) that are currently rearward (downstream) according to the movement direction of the railway vehicle.

In this case, it is preferable that the power converter body be configured to be mounted in an underfloor space of the railway vehicle; that the surface of the power converter body to which the first radiating fin unit and the second radiating fin unit are attached be a side face of the power converter body; that the air duct be attached along the side face of the power converter body to which the first radiating fin unit and the second radiating fin unit are fixed; and that the air duct be configured to guide air that is taken in from a position near the side face of the power converter body or from a position further away than the position near the side face while the railway vehicle is moving into the fin separation space and to then exhaust the air towards a lateral end of the first radiating fin unit or the second radiating fin unit. Here, when there is sufficient space to mount the first radiating fins and the second radiating fins on the side of the main power converter unit, the first radiating fins and the second radiating fins can easily be mounted in a way that makes it possible to effectively equalize the heat sink performance (heat dissipation performance) of the first radiating fins and the second radiating fins when dissipating heat from the main power converter unit. Moreover, here the first radiating fins and the second radiating fins are mounted on the side of the main power converter unit, and therefore the first radiating fins and the second radiating fins are exposed on the side of the railway vehicle while the railway vehicle is moving. This makes it possible to take in an airflow that is less turbulent than when taking in fresh outside air from beneath the railway vehicle (where other devices or the like may be attached), thereby making it possible for the first radiating fins and the second radiating fins to easily take in fresh outside air from the side of the railway vehicle. This, in turn, makes it possible to further improve the heat sink performance (heat dissipation performance) of a heat sink unit.

As described above, the present invention makes it possible to improve the overall heat sink performance (heat dissipation performance) of a heat sink unit that includes a plurality of radiating fins.

DETAILED DESCRIPTION OF EMBODIMENTS

Next, specific embodiments of the present invention will be described with reference to figures.

First, the configuration of a power converter100for a railway vehicle10according to Embodiment 1 of the present invention will be described with reference toFIGS. 1 to 5. The power converter100is one example of a “power converter for a railway vehicle” as described in the claims. In the following description, the movement direction of the railway vehicle10is defined to be the X axis direction, the direction of railway ties of a railway1that are orthogonal to the X axis direction is defined to be the Y axis direction, and the vertical direction that is mutually orthogonal to the X axis direction and the Y axis direction is defined to be the Z axis direction.

As illustrated inFIGS. 1 and 2, the power converter100according to Embodiment 1 of the present invention is mounted in an underfloor space11aof a vehicle body11of the railway vehicle10. Here, the overall configuration of the railway vehicle10will be described briefly. As illustrated inFIG. 1, the railway vehicle10includes the vehicle body11, a pantograph12that receives (collects) power supplied to an overhead line2, induction motors14(illustrated by the dashed lines) that use the power from the overhead line2to rotate driving wheels13, and a plurality of various other devices15such as an air conditioner and a controller. Moreover, while the railway vehicle10is moving, the power converter100converts the power from the overhead line2by switching semiconductor elements (not illustrated in the figure) and thereby controls the rotation of the induction motors14.

(Configuration of Power Converter)

The power converter100includes a semiconductor device20for converting power and a heat sink unit30for radiating heat produced by semiconductor elements in the semiconductor device20to the outside air. Moreover, as illustrated inFIG. 2, the power converter100is fixed in a suspended manner to a bottom surface11bof the vehicle body11in the underfloor space11aof the vehicle body11. Here, the semiconductor device20is arranged on the bottom surface11bside (a Z1 side), and the heat sink unit30is arranged on the railway1side (a Z2 side). Furthermore, the heat sink unit30includes radiating fins31(on an X1 side) and radiating fins32(on an X2 side) that are arranged separated from one another by a prescribed distance in the X axis direction in which the vehicle body11extends. The radiating fins31and32have thin plate shapes that extend down vertically (towards the railway1side) from the bottom surface (Z2 side) of the semiconductor device20and run parallel to the X axis direction. Note that here, the semiconductor device20is one example of the “power converter body” as recited in the claims. Moreover, the radiating fins31and32are examples of the “first radiating fin unit” and the “second radiating fin unit” as recited in the claims, respectively.

The radiating fins31include a plurality of thin plate-shaped fins31aand a base35to which roots of the fins31aare connected. The radiating fins32include a plurality of thin plate-shaped fins32aand a base36to which roots of the fins32aare connected. The number of the fins31ais equal to the number of the fins32a, and the radiating fins31and32have the same overall configuration as one another. The radiating fins31and32are attached to a bottom surface21of the semiconductor device20via the bases35and36, respectively. The bases35and36have a prescribed height H1(thickness in the Z axis direction). Moreover, the radiating fins31and32are symmetric on the Y1 and Y2 sides about a center line150that runs in the X axis direction (the movement direction) through the center of the semiconductor device20in the Y axis direction (the railway tie direction). Furthermore, the radiating fins31and32are arranged separated from one another by a space S of a prescribed width in the X axis direction. Note that here, the bottom surface21is one example of a “surface of the power converter body” as recited in the claims. Moreover, the space S is one example of a “fin separation space” as recited in the claims. Similarly, the height H1is one example of the “height” as recited in the claims.

As illustrated inFIG. 1, when the railway vehicle10travels in the X1 direction, air near the railway1flows in the X2 direction relative to the railway vehicle10and blows onto the heat sink unit30in the underfloor space11a. This airflow flows in the X2 direction through gaps between the fins31aand32athat extend in the X axis direction (seeFIG. 2). In this way, heat from the heat sink unit30is exhausted to the outside air. The remainder of this description assumes that the railway vehicle10travels in the X1 direction, that the radiating fins31are arranged on the upstream side (the X1 side) in the movement direction (the direction of travel), and that the radiating fins32are arranged on the downstream side (the X2 side) at a further rearward position.

As illustrated inFIGS. 2 and 3, in Embodiment 1 an air duct40is arranged in the space S between the radiating fins31and the radiating fins32. The air duct40is attached along the bottom surface21of the semiconductor device20to which the bases35and36is fixed. Moreover, the air duct40includes a pair of inlets41, a duct42, and an outlet43. Next, the configuration of the air duct40will be described in more detail.

(Detailed Configuration of Air Duct)

As illustrated inFIG. 3, each of the inlets41of the air duct40includes a first inlet41athat takes in the airflow when the railway vehicle10is traveling with the radiating fins31on the forward side in the movement direction as well as a second inlet41bthat takes in the airflow when the railway vehicle10is traveling with the radiating fins32on the forward side in the movement direction. Moreover, air-guiding plates44(illustrated by the dashed lines) are formed inside of the air duct40to guide the air that is taken in through the first inlets41aor the second inlets41b(depending on the movement direction) into the duct42. Furthermore, the inlets41(the first inlets41aand the second inlets41b) are respectively formed in side regions Q1and Q2that are separated outwards from the space S on both sides (that is, in the Y1 and Y2 directions) in the railway tie direction (the Y axis direction) that is orthogonal to the movement direction (the X axis direction).

The air duct40is formed spanning from the side region Q1on one side (the Y1 side) of the radiating fins31and32to the side region Q2on the other side (the Y2 side) in the railway tie direction. In other words, the duct42extends through the space S in the railway tie direction and is connected to the pair of inlets41that are formed on both sides in the railway tie direction. Moreover, the flow paths from the first inlets41aand the second inlets41bthat are separated from one another by the air-guiding plates44are joined together inside the duct42to form a single passage. Furthermore, the duct42extends through the space S with a height (height H1) that is substantially equal to the height H1of the base35(seeFIG. 2). The duct42has a rectangular cross-sectional shape. In addition, the air duct40that includes the inlets41and the duct42is attached along the bottom surface21of the semiconductor device20to which the base35is fixed.

The outlet43of the air duct40is formed in a bottom surface42a(the Z2 side) of the duct42and spans from near the sides31eand32e(the Y1 sides) of the radiating fins31and32to near the other sides31fand32f(the Y2 sides) in the railway tie direction. Moreover, the outlet43has a slit shape that is formed only at one location in the bottom surface42aand runs parallel to the Y axis direction in which the duct42extends. The outlet43creates an opening in the bottom surface42aof the duct42on the side on which the plurality of fins31a(and32a) are arranged. Therefore, as illustrated inFIGS. 3 and 5, the outlet43exhausts the air in the duct42into the space S on the side on which the plurality of fins31a(and32a) are formed. In addition, the configuration (shape) of the air duct40is symmetric, in the railway tie direction that is orthogonal to the movement direction, about the center line150(the dot-dashed line) that runs in the movement direction.

Forming the air duct40in this manner in Embodiment 1 ensures that the air (fresh outside air) that enters the inlets41in the movement direction when the railway vehicle10is moving is guided into the duct42and then travels through the duct42and the outlet43to be exhausted into the space S on the side on which the plurality of fins31a(and32a) are arranged.

As illustrated inFIG. 5, when the railway vehicle10(seeFIG. 1) is traveling in the X1 direction, for example, the airflow taken in from regions outside the radiating fins31and32(that is, from the side regions Q1and Q2(seeFIG. 3) that are near the bottom surface21of the semiconductor device20) flows through the air duct40and is guided into the space S. The air that is guided into the space S is then guided to movement direction-side ends32cof the radiating fins32. In other words, as illustrated inFIG. 4, the air duct40takes in air (the airflow) via the pair of first inlets41aand then guides that air through the duct42that extends to the space S and out of the slit-shaped outlet43to be exhausted into the space S. Then, the air (fresh outside air) exhausted into the space S is supplied to the movement direction-side ends32cof the radiating fins32.

Meanwhile, although the flow of air for this case is not illustrated inFIG. 5, when the railway vehicle10is traveling in the X2 direction, the air (airflow) taken in via the pair of second inlets41bis guided into the duct42and then exhausted through the outlet43into the space S. Then, the air (fresh outside air) exhausted into the space S is supplied to movement direction-side ends31cof the radiating fins31.

In this way, when the railway vehicle10is traveling with the radiating fins31on the forward side (the upstream side), the air (airflow) taken in by the air duct40from the regions outside the radiating fins31and32is directly and reliably (and sufficiently) supplied to the movement direction-side ends32cof the radiating fins32in the space S. Moreover, due to this, the air that is heated by the radiating fins31is exhausted diagonally downwards (towards the railway1) from the ends31c. Therefore, using the air duct40, air of the same temperature as the airflow (fresh outside air) supplied to the radiating fins31can be supplied to the ends32cand across the entire radiating fins32, thereby making it possible to maintain the heat dissipation performance of the downstream radiating fins32at the same level as the heat dissipation performance of the upstream radiating fins31.

In addition, as illustrated inFIG. 3, in Embodiment 1 the shape of the air duct40is symmetric in the movement direction about a center line160(the dot-dashed line) that runs through the space S in the railway tie direction (the Y axis direction) that is orthogonal to the movement direction (the X axis direction). Therefore, although above the flow of air in the air duct40was described for a case in which the railway vehicle10(seeFIG. 1) was traveling in the X1 direction, when the railway vehicle10is traveling in the X2 direction, the airflow is taken in through the pair of second inlets41bin the air duct40and then travels through the duct42and out of the outlet43to be supplied to the movement direction-side ends31cof the radiating fins31. In this way, the configuration similarly contributes to preventing a decrease in the heat dissipation performance of the downstream radiating fins31in this case as well. The power converter100according to Embodiment 1 is thus configured as described above.

Embodiment 1 makes it possible to achieve the following effects.

As described above, Embodiment 1 includes the air duct40that takes in air from the regions outside the radiating fins31and32while the railway vehicle10is moving and extends into the space S so as to guide the air that is taken in into that space S between the radiating fins31and32. In this way, when the railway vehicle10is traveling with the radiating fins31on the forward side (the upstream side), the airflow (fresh outside air) taken in from the regions outside the radiating fins31and32can be brought through the air duct40and reliably guided into the space S. Furthermore, the air (airflow) that is guided into the space S can be reliably (and sufficiently) supplied to the rearward (downstream) radiating fins32, thereby making it possible to maintain the heat dissipation performance of the radiating fins32at the same level as the heat dissipation performance of the upstream radiating fins31. This makes it possible to maximize the heat dissipation performance of the individual radiating fins (of the radiating fins31and32), thereby making it possible to improve the overall heat sink performance (heat dissipation performance) of the heat sink unit30of the railway vehicle10.

Moreover, in Embodiment 1, the air duct40includes the duct42that extends through the space S and has the same protrusion height as the protrusion height H1of the bases35and36of the radiating fins31and32as well as the outlet43that creates an opening in the surface (bottom surface)42aof the duct42on the side on which the plurality of fins31a(and32a) are arranged and exhausts the air in the duct42into the space S on the side on which the plurality of fins31a(and32a) are formed. Because the protrusion height of the duct42is equal to the protrusion height H1of the bases35and36, the duct42does not protrude out between the plurality of fins31aof the radiating fins31and the plurality of fins32aof the radiating fins32in the space S, thereby making it possible to easily allocate a passage (space) for the air in the space S. Therefore, the airflow (fresh outside air) exhausted from the outlet43is diffused downwards into the space S and can be effectively supplied to the fins31aof the radiating fins31or to the fins32aof the radiating fins32, depending on which are currently rearward (downstream) according to the movement direction of the railway vehicle10.

Moreover, in Embodiment 1, attaching the duct42along the surface (bottom surface)21of the semiconductor device20to which the base35is fixed makes it possible to easily arrange the duct42that has the same protrusion height as the protrusion height H1of the base35so as to extend along the surface (bottom surface)21of the semiconductor device20and into the space S.

Furthermore, in Embodiment 1 the duct42is configured to extend through the space S in the railway tie direction (the Y axis direction) that is orthogonal to the movement direction. This makes it possible to guide the airflow (fresh outside air) that is taken in from the regions outside the radiating fins31and32through the duct42and into the space S across a wide region (range) that extends from the end sides (the Y1 and Y2 sides) to the center side in the railway tie direction (the Y axis direction).

In addition, in Embodiment 1 the outlet43in the duct42is formed spanning from near the side31e(and32e) of the radiating fins31and32to near the other side31f(and32f) in the railway tie direction (the Y axis direction). This makes it possible to exhaust the airflow (fresh outside air) that is taken in from the regions outside the radiating fins31and32through the outlet43and into the space S across a wide range that spans from near the side31e(and32e) to near the other side31f(and32f) in the railway tie direction (the Y axis direction). Therefore, the airflow that is diffused into the space S can be uniformly supplied along the railway tie direction (the Y axis direction) to the fins31aof the radiating fins31or to the fins32aof the radiating fins32, depending on which are currently rearward (downstream) according to the movement direction of the railway vehicle10.

Moreover, in Embodiment 1 the outlet43is configured to be slit-shaped and to extend along the same direction in which the duct42extends. This makes it possible to exhaust the airflow (fresh outside air) that is taken in from the regions outside the radiating fins31and32through the slit-shaped outlet43and into the space S in an air curtain-shaped flow pattern. Therefore, this air curtain-shaped airflow can be uniformly supplied along the railway tie direction (the Y axis direction) from near the side31e(or32e) to near the other side31f(or32f) of the fins31a(or32a), depending on which are currently rearward (downstream) according to the movement direction of the railway vehicle10.

Furthermore, in Embodiment 1 a single outlet43is formed extending along the same direction in which the duct42extends. This makes it possible to adjust the length of the single outlet43in accordance with the length of the duct42that extends through the space S, thereby making it possible to shape the flow pattern of the airflow that is exhausted into the space S from the outlet43to have a desired shape.

In addition, in Embodiment 1, the air that enters the air duct40in the movement direction via the inlets41is guided into the duct42, and this air travels through the duct42and is exhausted through the outlet43and into the space S on the side on which the plurality of fins31a(and32a) are arranged. This makes it possible to easily take in, via the inlets41, the airflow flowing along the regions of the railway vehicle10on the outer sides (in the side direction) of the fins31aor32a(of the radiating fins31or32) in the railway tie direction (the Y axis direction) and also makes it possible to guide that air through the duct-shaped duct42that is connected to the inlets41and then collect that air in the space S. Then, that air can be reliably supplied to the rearward (downstream) fins31aor32a(of the radiating fins31or32) through the outlet43that forms an opening into the space S.

Moreover, Embodiment 1 includes the first inlets41athat take in the airflow when the railway vehicle10is traveling with the radiating fins31on the forward side in the movement direction as well as the second inlets41bthat take in the airflow when the railway vehicle10is traveling with the radiating fins32on the forward side in the movement direction. Furthermore, the air-guiding plates44are formed in the air duct40to guide the air that is taken in through the first inlets41aor the second inlets41b(depending on the movement direction) into the duct42. In this way, the airflow (fresh outside air) that is taken in through the first inlets41aor the second inlets41b(depending on the movement direction of the railway vehicle10) can be reliably supplied from the space S to the rearward (downstream) fins31aor32a(of the radiating fins31or32).

In addition, in Embodiment 1, the air duct40is formed spanning from the region (side region) Q1positioned further outwards than the space S on one side (the Y1 side) of the radiating fins31and32to the region (side region) Q2positioned further outwards than the space S on the other side (the Y2 side) in the railway tie direction (the Y axis direction) that is orthogonal to the movement direction. This makes it possible to reliably take in the airflow (fresh outside air) from the region (side region) Q1positioned further outwards than the space S on one side (the Y1 side) in the railway tie direction (the Y axis direction) of the railway vehicle10and from the region (side region) Q2positioned further outwards than the space S on the other side (the Y2 side) and to then reliably guide that air into the space S. Therefore, the overall heat sink performance (heat dissipation performance) of the heat sink unit30of the railway vehicle10can be maintained at a prescribed level without being significantly affected by the traveling conditions of the railway vehicle10or the strength of the resulting airflow.

Moreover, in Embodiment 1, the inlets41of the air duct40are formed in regions (the side regions Q1and Q2) positioned on one side (the Y1 side) and on the other side (the Y2 side) of the space S, and these regions are respectively separated outwards from the space S in both directions (that is, in the Y1 direction and in the Y2 direction) in the railway tie direction (the Y axis direction) that is orthogonal to the movement direction. This makes it possible to reliably prevent air that passes through and is heated by the radiating fins31or32while the railway vehicle10is moving from being taken in again via the inlets41of the air duct40.

Furthermore, in Embodiment 1, the air duct40is configured to have a shape that is symmetric in the movement direction about the center line160that runs through the space S in the railway tie direction (the Y axis direction) that is orthogonal to the movement direction of the railway vehicle10. This makes it possible to reduce variation between the amounts of heat dissipated by the radiating fins31and32regardless of whether the railway vehicle10is traveling with the radiating fin31side or the radiating fin32side in the forward direction. In other words, this makes it possible to sufficiently improve the heat sink performance of Embodiment 1 regardless of the movement direction of the railway vehicle10.

In addition, in Embodiment 1, the air duct40is configured to have a shape that is also symmetric, in the railway tie direction (the Y axis direction) that is orthogonal to the movement direction of the railway vehicle10, about the center line150that runs in the movement direction. This makes it possible to uniformly take in the airflow (fresh outside air) from the region (side region) Q1positioned further outwards than the space S on one side (the Y1 side) in the railway tie direction (the Y axis direction) of the railway vehicle10and from the region (side region) Q2positioned further outwards than the space S on the other side (the Y2 side) and to then guide that air into the space S. Therefore, the overall heat sink performance (heat dissipation performance) of the heat sink unit30of the railway vehicle10can be maintained at a prescribed level without being significantly affected by the traveling conditions of the railway vehicle10or the strength of the resulting airflow.

Moreover, in Embodiment 1 the duct42extends through the space S in the railway tie direction (the Y axis direction) that is orthogonal to the movement direction. Therefore, when the plurality of fins31aand32aof the radiating fins31and32are formed extending in the vertical direction (the Z axis direction) of the railway vehicle10, the airflow (fresh outside air) exhausted from the outlet43can be diffused into the space S and can then be effectively supplied to the fins31aor32a(of the radiating fins31or32), depending on which are currently rearward (downstream) according to the movement direction of the railway vehicle10.

Furthermore, in Embodiment 1, the radiating fins31and32are mounted in the underfloor space11aof the railway vehicle10, and the air duct40is attached along the bottom surface21of the semiconductor device20to which the radiating fins31and32are fixed. In addition, the air duct40is configured to guide air (airflow) taken in from positions near the bottom surface21of the semiconductor device20while the railway vehicle10is moving into the space S between the radiating fins31and32and then exhaust that air to the movement direction-side ends32c(or31c) of the radiating fins31or32. Therefore, when there is sufficient space to mount the radiating fins31and32beneath the semiconductor device20(on the Z2 side), the radiating fins31and32can easily be mounted in a way that makes it possible to effectively equalize the heat sink performance (heat dissipation performance) of the radiating fins31and32when dissipating heat from the semiconductor device20.

Next, Embodiment 2 will be described with reference toFIGS. 1, 6, and 7. Embodiment 2 will be described using an example in which the shape and arrangement of inlets241of an air duct240are different from Embodiment 1. Note that in the figures, the same reference characters are used for components that are the same as in Embodiment 1.

As illustrated inFIG. 6, a power converter200(seeFIG. 1) according to Embodiment 2 of the present invention includes a heat sink unit230. Moreover, the air duct240is mounted between radiating fins31and32of the heat sink unit230. Note that here, the power converter200is one example of a “power converter for a railway vehicle” as described in the claims.

As illustrated inFIG. 7, in Embodiment 2 the air duct240includes the inlets241, a duct42, and an outlet43. Moreover, the inlets241are arranged on a side face22a(on the Y1 side) and on a side face22b(on the Y2 side) of a semiconductor device20at positions further outwards than a space S. In other words, the inlets241are arranged on the faces on both sides of the semiconductor device20(that is, on the side faces22aand22b) at positions further outwards than the space S. Furthermore, the height H2(length in the Z axis direction) of the inlets241is greater than the height H1(length in the Z axis direction) of the duct42. In addition, air-guiding plates244aand244b(illustrated by the dashed lines) are formed inside of the inlets241to guide air (airflow) that is taken in through first inlets241aor second inlets241b(depending on the movement direction) into the duct42. In this way, as illustrated inFIG. 6, the air (airflow) that flows along the side faces22aand22bat positions higher (that is, on the Z1 side) than a bottom surface21of the semiconductor device20while a railway vehicle10is moving is taken in through the inlets241, and then the air that is taken in through the inlets241is guided into the duct42. Note that here, the side faces22aand22bare an example of “surfaces on both sides of the power converter body” as described in the claims. Similarly, the air-guiding plates244aand244bare an example of “air-guiding plates” as described in the claims.

When the railway vehicle10(seeFIG. 1) is traveling in the X1 direction, for example, the airflow taken in from along the side faces22aand22bof the semiconductor device20via a pair of first inlets241aflows through the air duct240and is guided into the space S. Then, the air that is guided into the space S is guided to movement direction-side ends32cof the radiating fins32. Moreover, when the railway vehicle10is traveling in the X2 direction, the air (fresh outside air) taken in through a pair of second inlets241btravels through the duct42and is exhausted from the outlet43into the space S to be supplied to movement direction-side ends31cof the radiating fins31. The rest of the configuration of the power converter200according to Embodiment 2 is the same as in Embodiment 1.

As described above, in Embodiment 2 the air duct240is attached to the bottom surface21of the semiconductor device20. Moreover, the inlets241are arranged on the side faces22aand22bthe semiconductor device20at positions further outwards than the space S. In other words, the inlets241are arranged at positions further outwards than the space S so as to sandwich the faces on both sides of the semiconductor device20(that is, the side faces22aand22b). Furthermore, the air duct240is configured to take in, through the inlets241, the air that flows along the faces on both sides of the semiconductor device20(the side faces22aand22b) while the railway vehicle10is moving and to then guide the air taken in through the inlets241into the duct42. This makes it possible to effectively take in the airflow (fresh outside air) that flows along the faces on both sides of the semiconductor device20(the side faces22aand22b) and then effectively supply that air to fins31aor32a(of the radiating fins31or32), depending on which are currently rearward (downstream) according to the movement direction of the railway vehicle10.

Moreover, in Embodiment 2, the length (height) H2of the inlets241is greater than the length (height) H1of the duct42in the direction (the Z axis direction) that is orthogonal to the movement direction. This makes it possible to increase the opening area of the inlets241, thereby making it possible to temporarily collect more of the airflow (fresh outside air) that was taken in within the duct42and then vigorously exhaust the air collected in the duct42into the space S. The rest of the effects of Embodiment 2 are the same as in Embodiment 1.

Next, Embodiment 3 will be described with reference toFIGS. 1, 8, and 9. Embodiment 3 will be described using an example in which an air-guiding member50is attached to the air duct40of Embodiment 1. Note that in the figures, the same reference characters are used for components that are the same as in Embodiment 1.

As illustrated inFIG. 9, a power converter300(seeFIG. 1) according to Embodiment 3 of the present invention includes a heat sink unit330in which the additional air-guiding member50is attached to the air duct40.

More specifically, as illustrated inFIG. 8, the air-guiding member50includes a leg51a(on the Y1 side) and a leg51b(on the Y2 side) that are welded to a bottom surface42aof a duct42at positions slightly outwards from both lengthwise ends of an outlet43. The air-guiding member50also includes an integrated flat plate-shaped air guide52that connects together the pair of legs51aand51bin the Y axis direction (the railway tie direction). The air guide52is arranged separated from the bottom surface42aof the duct42by a prescribed distance in the Z2 direction. Moreover, the air-guiding member50is attached to the duct42with the center position of the air-guiding member50in the X axis direction being aligned with the outlet43. Note that here, the power converter300is one example of a “power converter for a railway vehicle” as described in the claims. Similarly, the air-guiding member50is an example of an “air-guiding plate” as described in the claims.

The air-guiding member50guides air that is exhausted through the outlet43into a space S on a side on which fins31a(and32a) are formed towards movement direction-side ends32c(or31c) of radiating fins31or32. In this way, both the air duct40and the air-guiding member50can be used to efficiently and reliably guide the airflow (fresh outside air) to the movement direction-side ends31c(or32c) of the fins31a(or32a), depending on which are currently rearward (downstream) according to the movement direction of a railway vehicle10.

As illustrated inFIG. 9, when the railway vehicle10is traveling with the radiating fins31on the forward side (upstream side), for example, the air exhausted downwards (in the Z2 direction) from the outlet43hits a rear surface52aof the air guide52and is redirected into the X2 direction. Then, the air (fresh outside air) that was redirected into the X2 direction is reliably supplied to the movement direction-side ends32cof the radiating fins32. Furthermore, although the flow of air for this case is not illustrated inFIG. 9, when the railway vehicle10is traveling in the X2 direction, the air exhausted downwards (in the Z2 direction) from the outlet43hits the rear surface52aof the air guide52and is redirected into the X1 direction, and then this redirected air is reliably supplied to the movement direction-side ends31cof the radiating fins31. The rest of the configuration of the power converter300according to Embodiment 3 is the same as in Embodiment 1.

As described above, in Embodiment 3 the heat sink unit330includes the air-guiding member50, which guides air that is exhausted through the outlet43into the space S on the side on which the fins31a(and32a) are formed towards the movement direction-side ends31c(or32c) of the radiating fins31or32. This makes it possible to use the air-guiding member50to efficiently and reliably guide the airflow (fresh outside air) to the movement direction-side ends31c(or32c) of the fins31a(or32a), depending on which are currently rearward (downstream) according to the movement direction of a railway vehicle10. The rest of the effects of Embodiment 3 are the same as in Embodiment 1.

Next, Embodiment 4 will be described with reference toFIGS. 10 to 12. Embodiment 4 will be described using an example in which radiating fins431and432and an air duct440that are configured similar to the radiating fins31and32and the air duct40of Embodiment 1 are arranged along a side of a semiconductor device420. Note that in the figures, the same reference characters are used for components that are the same as in Embodiment 1.

As illustrated inFIGS. 10 and 11, a power converter400according to Embodiment 4 of the present invention includes the semiconductor device420and a heat sink unit430. Moreover, the heat sink unit430is arranged on a side face (the face on the Y2 side) of the semiconductor device420, which is fixed to a bottom surface11bof a vehicle body11. Furthermore, the heat sink unit430includes radiating fins431(on the X1 side) and radiating fins432(on the X2 side) that are arranged separated from one another by a prescribed distance in the X axis direction in which the vehicle body11extends. The radiating fins431and432have thin plate shapes that extend outwards (in the Y2 direction) from the side face on the Y2 side of the semiconductor device420and run parallel to the X axis direction. Note that here, the semiconductor device420is one example of a “power converter body” as described in the claims. Moreover, the radiating fins431and432are examples of “first radiating fin unit” and “second radiating fin unit” as recited in the claims, respectively.

The radiating fins431include a plurality of thin plate-shaped fins431aand a base435to which roots are connected. The radiating fins432include a plurality of thin plate-shaped fins432aand a base436to which roots are connected. The radiating fins431and432are attached to a side face421of the semiconductor device420via the bases435and436, respectively. The bases435and436have a prescribed protrusion height H41(thickness in the Y axis direction). Furthermore, the radiating fins431and432are arranged separated from one another by a space S4of a prescribed width in the X axis direction. Note that here, the side face421is one example of a “surface of the power converter body” as recited in the claims. Similarly, the space S4is one example of a “fin separation space” as recited in the claims. Moreover, the side face421is one example of a “surface of the power converter body” as recited in the claims.

As illustrated inFIG. 10, when a railway vehicle410travels in the X1 direction, air near a railway1flows in the X2 direction relative to the railway vehicle410and blows onto the heat sink unit430in an underfloor space11a. This airflow flows in the X2 direction through gaps between the fins431aand432athat extend in the X axis direction (seeFIG. 11). In this way, heat from the heat sink unit430is exhausted to the outside air. The remainder of this description assumes that the railway vehicle410travels in the X1 direction, that the radiating fins431are arranged on the upstream side (the X1 side) in the movement direction (the direction of travel), and that the radiating fins432are arranged on the downstream side (the X2 side) at a further rearward position.

As illustrated inFIGS. 11 and 12, in Embodiment 4 the air duct440is arranged in the space S4between the radiating fins431and the radiating fins432. The air duct440is attached along the side face421of the semiconductor device420to which the base435is fixed. Moreover, the air duct440includes a pair of inlets441, a duct442, and an outlet443.

As illustrated inFIG. 12, each of the inlets441of the air duct440includes a first inlet441athat takes in the airflow when the railway vehicle410is traveling with the radiating fins431on the forward side in the movement direction as well as a second inlet441bthat takes in the airflow when the railway vehicle410is traveling with the radiating fins432on the forward side in the movement direction. Moreover, air-guiding plates444(illustrated by the dashed lines inFIG. 12) are formed inside of the air duct440to guide the air that is taken in through the first inlets441aor the second inlets441b(depending on the movement direction) into the duct442. Furthermore, the inlets441(the first inlets441aand the second inlets441b) are respectively formed in regions Q41and Q42that are separated outwards from the space S4on both sides (that is, in the Z1 and Z2 directions) in the vertical direction of the railway vehicle410(the Z axis direction) that is orthogonal to the movement direction (the X axis direction). Note that here, the air-guiding plates444are an example of “air-guiding plates” as recited in the claims.

The air duct440is formed spanning from the region Q41on one side (the Z2 side) of the radiating fins431and432to the region Q42on the other side (the Z1 side) in the Z axis direction. Moreover, the flow paths from the first inlets441aand the second inlets441bthat are separated from one another by the air-guiding plates444are joined together inside the duct442to form a single passage. Furthermore, the duct442extends through the space S4with a height (height H41) in the Y axis direction that is substantially equal to the length H41of the base435in the Y axis direction (seeFIG. 11). The duct442has a rectangular cross-sectional shape. In addition, the air duct440that includes the inlets441and the duct442is attached along the side face421of the semiconductor device420to which the base435is fixed.

The outlet443of the air duct440is formed in a side face442a(the Y2 side) of the duct442and spans from near the sides431eand432e(the Z2 sides) of the radiating fins431and432to near the other sides431fand432f(the Z1 sides) in the Z axis direction. Moreover, the outlet443has a slit shape that is formed only at one location in the side face442aand runs parallel to the Z axis direction in which the duct442extends. The outlet443creates an opening in the side face442aof the duct442on the side on which the plurality of fins431a(and432a) are arranged.

Forming the air duct440in this manner in Embodiment 4 ensures that the air (fresh outside air) that enters the inlets441in the movement direction when the railway vehicle410is moving is guided into the duct442and then travels through the duct442and the outlet443to be exhausted into the space S4on the side on which the plurality of fins431a(and432a) are arranged.

As illustrated inFIG. 12, when the railway vehicle410(seeFIG. 10) is traveling in the X1 direction, for example, the airflow taken in from regions outside the radiating fins431and432(that is, from the regions Q41and Q42that are near the side face421of the semiconductor device420) flows through the air duct440and is guided into the space S4. The air that is guided into the space S4is then guided to movement direction-side ends432cof the radiating fins432. In other words, the air duct440takes in air (the airflow) via the pair of first inlets441aand then guides that air through the duct442that extends to the space S4and out of the slit-shaped outlet443to be exhausted into the space S4. Then, the air (fresh outside air) exhausted into the space S4is supplied to the movement direction-side ends432cof the radiating fins432.

Meanwhile, although the flow of air for this case is not illustrated inFIG. 12, when the railway vehicle410is traveling in the X2 direction, the air (airflow) taken in via the pair of second inlets441bis guided into the duct442and then exhausted through the outlet443into the space S4. Then, the air (fresh outside air) exhausted into the space S4is supplied to movement direction-side ends431cof the radiating fins431.

In this way, when the railway vehicle410is traveling with the radiating fins431on the forward side (the upstream side), the air (airflow) taken in by the air duct440from the regions outside the radiating fins431and432is directly and reliably (and sufficiently) supplied to the movement direction-side ends432cof the radiating fins432in the space S4. Moreover, due to this, the air that is heated by the radiating fins431is exhausted diagonally outwards (towards the Y2 side) from the ends431c. Therefore, using the air duct440, air of the same temperature as the airflow (fresh outside air) supplied to the radiating fins431can be supplied to the ends432cand across the entire radiating fins432, thereby making it possible to maintain the heat dissipation performance of the downstream radiating fins432at the same level as the heat dissipation performance of the upstream radiating fins431.

In the power converter400according to Embodiment 4, the configuration of the power converter100of Embodiment 1, in which the heat sink unit30is arranged beneath the semiconductor device20, is replaced by a configuration in which the heat sink unit430is arranged on the side of the semiconductor device420. Therefore, the rest of the configuration of the power converter400according to Embodiment 4 is the same as the configuration of the power converter100according to Embodiment 1 except in that the Y axis direction and the Z axis direction are respectively switched with the Z axis direction and the Y axis direction.

Embodiment 4 makes it possible to achieve the following effects.

As described above, Embodiment 4 includes the air duct440that takes in air from the regions outside the radiating fins431and432while the railway vehicle410is moving and extends into the space S4so as to guide the air that is taken in into that space S4between the radiating fins431and432. In this way, when the railway vehicle410is traveling with the radiating fins431on the forward side (the upstream side), the airflow (fresh outside air) taken in from the regions outside the radiating fins431and432can be brought through the air duct440and reliably guided into the space S4. Furthermore, the air (airflow) that is guided into the space S4can be reliably (and sufficiently) supplied to the rearward (downstream) radiating fins432, thereby making it possible to maintain the heat dissipation performance of the radiating fins432at the same level as the heat dissipation performance of the upstream radiating fins431. This makes it possible to maximize the heat dissipation performance of the individual radiating fins (of the radiating fins431and432), thereby making it possible to improve the overall heat sink performance (heat dissipation performance) of the heat sink unit430of the railway vehicle410.

Moreover, in Embodiment 4, the air duct440includes the duct442that extends through the space S4and has the same protrusion height as the protrusion height H41of the bases435and436of the radiating fins431and432as well as the outlet443that creates an opening in the surface (side face)442aof the duct442on the side on which the plurality of fins431a(and432a) are arranged and exhausts the air in the duct442into the space S4on the side on which the plurality of fins431a(and432a) are formed. Because the protrusion height of the duct442is equal to the protrusion height H41of the base435, the duct442does not protrude out between the plurality of fins431aof the radiating fins431and the plurality of fins432aof the radiating fins432in the space S4, thereby making it possible to easily allocate a passage (space) for the air in the space S4. Therefore, the airflow (fresh outside air) exhausted from the outlet443is diffused outwards into the space S4and can be effectively supplied to the fins431aof the radiating fins431or to the fins432aof the radiating fins432, depending on which are currently rearward (downstream) according to the movement direction of the railway vehicle410.

Moreover, in Embodiment 4 the duct442extends through the space S4in the vertical direction of the railway vehicle410(the Z axis direction) that is orthogonal to the movement direction. Therefore, when the plurality of fins431aand432aof the radiating fins431and432are formed extending in the railway tie direction (in the Y axis direction) of the railway vehicle410, the airflow (fresh outside air) exhausted from the outlet443can be diffused into the space S4and can then be effectively supplied to the fins431aor432a(of the radiating fins431or432), depending on which are currently rearward (downstream) according to the movement direction of the railway vehicle410.

Furthermore, in Embodiment 4, the radiating fins431and432are mounted in the underfloor space11aof the railway vehicle410, and the air duct440is attached along the side face421of the semiconductor device420to which the radiating fins431and432are fixed. In addition, the air duct440is configured to guide air (airflow) taken in from positions near the side face421of the semiconductor device420while the railway vehicle410is moving into the space S4between the radiating fins431and432and then exhaust that air to the movement direction-side ends432c(or431c) of the radiating fins431or432. Therefore, when there is sufficient space to mount the radiating fins431and432on the side of the semiconductor device420(on the Y1 side or on the Y2 side), the radiating fins431and432can easily be mounted in a way that makes it possible to effectively equalize the heat sink performance (heat dissipation performance) of the radiating fins431and432when dissipating heat from the semiconductor device420. Moreover, in Embodiment 4, the radiating fins431and432are mounted on the side (the Y2 side) of the semiconductor device420, and therefore the radiating fins431and432are exposed on the side (the Y2 side) of the railway vehicle410while the railway vehicle410is moving. This makes it possible to take in an airflow that is less turbulent than when taking in fresh outside air from beneath the railway vehicle410(where other devices or the like may be attached), thereby making it possible for the radiating fins431and432to easily take in fresh outside air from the side (the Y2 side) of the railway vehicle410. This, in turn, makes it possible to further improve the heat sink performance (heat dissipation performance) of the heat sink unit430. The rest of the effects of Embodiment 4 are the same as in Embodiment 1.

Next, Embodiment 5 will be described with reference toFIGS. 10, 13, and 14.

Embodiment 5 will be described using an example in which the shape and arrangement of inlets541of an air duct540are different from Embodiment 4. Note that in the figures, the same reference characters are used for components that are the same as in Embodiment 4.

As illustrated inFIG. 13, a power converter500(seeFIG. 10) according to Embodiment 5 of the present invention includes a heat sink unit530. Moreover, the air duct540is mounted between radiating fins431and432of the heat sink unit530. Note that here, the power converter500is one example of a “power converter for a railway vehicle” as described in the claims.

As illustrated inFIG. 13, in Embodiment 5 the air duct540includes the inlets541, a duct442, and an outlet443. Moreover, the inlets541are arranged on a bottom surface422a(on the Z2 side) and on a top surface422b(on the Z1 side) of a semiconductor device420at positions further outwards than a space S4. In other words, the inlets541are arranged at positions further outwards than the space S4so as to sandwich the surfaces on both sides of the semiconductor device420(that is, the bottom surface422aand the top surface422b). Furthermore, the length H52of the inlets541in the Y axis direction is greater than the length H41of the duct442. Therefore, as illustrated inFIG. 14, the air (airflow) that flows along the bottom surface422aand the top surface422bat positions further outwards (on the Y2 side) than a side face421of the semiconductor device420while a railway vehicle410is moving is taken in through the inlets541, and then the air that is taken in through the inlets541is guided into the duct442. Note that here, the bottom surface422aand the top surface422bare an example of “surfaces on both sides of the power converter body.”

In this way, when the railway vehicle410(seeFIG. 11) is traveling in the X1 direction, the airflow taken in from along the bottom surface422aand the top surface422bof the semiconductor device420via a pair of first inlets541aflows through the air duct540and is guided into the space S4. Then, the air that is guided into the space S4is guided to movement direction-side ends432cof the radiating fins432. Moreover, when the railway vehicle410is traveling in the X2 direction, the air (fresh outside air) taken in through a pair of second inlets541btravels through the duct442and is exhausted from the outlet443into the space S4to be supplied to movement direction-side ends431cof the radiating fins431.

In the power converter500according to Embodiment 5, the configuration of the power converter200of Embodiment 2, in which the heat sink unit230is arranged beneath the semiconductor device20, is replaced by a configuration in which the heat sink unit530is arranged on the side of the semiconductor device420. Therefore, the rest of the configuration of the power converter500according to Embodiment 5 is the same as the configuration of the power converter200according to Embodiment 2 except in that the Y axis direction and the Z axis direction are respectively switched with the Z axis direction and the Y axis direction.

As described above, in Embodiment 5 the air duct540is attached to the side face421of the semiconductor device420. Moreover, the inlets541are arranged on the bottom surface422aand the top surface422bof the semiconductor device420at positions further outwards than the space S4. In other words, the inlets541are arranged at positions further outwards than the space S4so as to sandwich the surfaces on both sides of the semiconductor device420(that is, the bottom surface422aand the top surface422b). Furthermore, the air duct540is configured to take in, through the inlets541, the air that flows along the surfaces on both sides of the semiconductor device420(the bottom surface422aand the top surface422b) while the railway vehicle410is moving and to then guide the air taken in through the inlets541into the duct442. This makes it possible to effectively take in the airflow (fresh outside air) that flows along the surfaces on both sides of the semiconductor device420(the bottom surface422aand the top surface422b) and then effectively supply that air to fins431aor432a(of the radiating fins431or432), depending on which are currently rearward (downstream) according to the movement direction of the railway vehicle410.

Moreover, in Embodiment 5, the length H52of the inlets541is greater than the length H41of the duct442in the direction (the Y axis direction) that is orthogonal to the movement direction. This makes it possible to increase the opening area of the inlets541, thereby making it possible to temporarily collect more of the airflow (fresh outside air) that was taken in within the duct442and then vigorously exhaust the air collected in the duct442into the space S4. Moreover, in Embodiment 5, the radiating fins431and432are mounted on the side (the Y2 side) of the semiconductor device420, and therefore the radiating fins431and432are exposed on the side (the Y2 side) of the railway vehicle410while the railway vehicle410is moving. This makes it possible to take in an airflow that is less turbulent than when taking in fresh outside air from beneath the railway vehicle410(where other devices or the like may be attached), thereby making it possible for the radiating fins431and432to easily take in fresh outside air from the side (the Y2 side) of the railway vehicle410. This, in turn, makes it possible to further improve the heat sink performance (heat dissipation performance) of the heat sink unit530. The rest of the effects of Embodiment 5 are the same as in Embodiment 2.

Next, Embodiment 6 will be described with reference toFIGS. 10 and 15. Embodiment 6 will be described using an example in which an air-guiding member650is attached to the air duct440of Embodiment 4. Note that in the figures, the same reference characters are used for components that are the same as in Embodiment 4.

As illustrated inFIG. 15, a power converter600(seeFIG. 10) according to Embodiment 6 of the present invention includes a heat sink unit630in which the additional air-guiding member650is attached to the air duct440. Note that here, the air-guiding member650is an example of an “air-guiding plate” as recited in the claims.

The air-guiding member650guides air that is exhausted through an outlet443into a space S4on a side on which fins431a(and432a) are formed towards movement direction-side ends432c(or431c) of radiating fins431or432. In this way, both the air duct440and the air-guiding member650can be used to efficiently and reliably guide the airflow (fresh outside air) to the movement direction-side ends431c(or432c) of the fins431a(or432a), depending on which are currently rearward (downstream) according to the movement direction of a railway vehicle410.

As illustrated inFIG. 15, when the railway vehicle410is traveling with the radiating fins431on the forward side (upstream side), for example, the air exhausted outwards (in the Y2 direction) from the outlet443is redirected into the X2 direction. Then, the air (fresh outside air) that was redirected into the X2 direction is reliably supplied to the movement direction-side ends432cof the radiating fins432. Furthermore, although the flow of air for this case is not illustrated inFIG. 15, when the railway vehicle410is traveling in the X2 direction, the air exhausted outwards (in the Y2 direction) from the outlet443is redirected into the X1 direction, and then this redirected air is reliably supplied to the movement direction-side ends431cof the radiating fins431.

In the power converter600according to Embodiment 6, the configuration of the power converter300of Embodiment 3, in which the heat sink unit330is arranged beneath the semiconductor device20, is replaced by a configuration in which the heat sink unit630is arranged on the side of a semiconductor device420. Therefore, the rest of the configuration of the power converter600according to Embodiment 6 is the same as the configuration of the power converter300according to Embodiment 3 except in that the Y axis direction and the Z axis direction are respectively switched with the Z axis direction and the Y axis direction.

As described above, in Embodiment 6 the heat sink unit630includes the air-guiding member650, which guides air that is exhausted through the outlet443into the space S4on the side on which the fins431a(and432a) are formed towards the movement direction-side ends431c(or432c) of the radiating fins431or432. This makes it possible to use the air-guiding member650to efficiently and reliably guide the airflow (fresh outside air) to the movement direction-side ends431c(or432c) of the fins431a(or432a), depending on which are currently rearward (downstream) according to the movement direction of a railway vehicle410. Moreover, in Embodiment 6, the radiating fins431and432are mounted on the side (the Y2 side) of the semiconductor device420, and therefore the radiating fins431and432are exposed on the side (the Y2 side) of the railway vehicle410while the railway vehicle410is moving. This makes it possible to take in an airflow that is less turbulent than when taking in fresh outside air from beneath the railway vehicle410(where other devices or the like may be attached), thereby making it possible for the radiating fins431and432to easily take in fresh outside air from the side (the Y2 side) of the railway vehicle410. This, in turn, makes it possible to further improve the heat sink performance (heat dissipation performance) of the heat sink unit630. The rest of the effects of Embodiment 6 are the same as in Embodiment 3.

Modification Examples

The embodiments described above are only examples in all respects and do not limit the present invention in any way. The scope of the present invention is defined by the claims, not by the descriptions of the embodiments above. Furthermore, the scope of the present invention also includes all changes (modification examples) included within the scope of the claims or their equivalents.

For example, in Embodiments 1 to 6 as described above, the present invention was applied to the power converters100,200,300,400,500, and600that were mounted in the underfloor space11aof the vehicle body11. However, the present invention is not limited to this example. The present invention may also be applied to power converters that are mounted on the roof of the vehicle body11, for example.

Moreover, although a single slit-shaped outlet43was formed in the bottom surface42aof the duct42in Embodiment 1, the present invention is not limited to this example. In other words, a plurality of shorter outlets43may be formed separately from one another at a prescribed interval. In this case, the plurality of outlets43may be round holes or polygonal holes (such as rectangular holes). This makes it possible to adjust parameters such as the number and positioning of the outlets43in accordance with the length of the duct42that extends through the space S, thereby making it possible to shape the flow pattern of the airflow (fresh outside air) that is exhausted into the space S from the outlets43to have a desired shape.

Moreover, although a single slit-shaped outlet443was formed in the side face442aof the duct442in Embodiments 4 to 6, the present invention is not limited to this example. In other words, a plurality of shorter outlets443may be formed separately from one another at a prescribed interval. In this case, the plurality of outlets443may be round holes or polygonal holes (such as rectangular holes). This makes it possible to adjust parameters such as the number and positioning of the outlets443in accordance with the length of the duct442that extends through the space S4, thereby making it possible to shape the flow pattern of the airflow (fresh outside air) that is exhausted into the space S4from the outlets443to have a desired shape.

Furthermore, although the duct42(and442) was configured to have a rectangular cross-sectional shape in Embodiments 1 to 6 as described above, the present invention is not limited to this example. The “air duct” of the present invention may instead be configured using a duct42(or442) that has a circular cross-sectional shape, for example.

In addition, although the height of the duct42was configured to be equal to the height H1of the bases35and36in Embodiments 1 to 3, the present invention is not limited to this example. The height of the duct42may instead be slightly less than the height H1, for example.

Moreover, although the length of the duct442was configured to be equal to the length H41of the bases435and436in the Y axis direction in Embodiments 4 to 6, the present invention is not limited to this example. The length of the duct442may instead be slightly less than the length H41in the Y axis direction, for example.

Furthermore, although the radiating fins431and432and the air duct440(or540) were arranged on the side face on one side (the Y2 side) of the semiconductor device420in Embodiments 4 to 6 as described above, the present invention is not limited to this example. The radiating fins431and432and the air duct440(or540) may instead be arranged on the side face on the other side (the Y1 side) of the semiconductor device420. Alternatively, the radiating fins431and432and the air duct440(or540) may be arranged on the side faces on both sides of the semiconductor device420.

In addition, although the radiating fins31and32and the air duct40(or240) were arranged on the bottom surface of the semiconductor device20in Embodiments 1 to 3 as described above, and the radiating fins431and432and the air duct440(540) were arranged on the side face of the semiconductor device420in Embodiments 4 to 6, the present invention is not limited to these examples. The plurality of radiating fins may be arranged both on the bottom surface and on the side faces of the main power converter unit.

Moreover, in Embodiments 1 to 6 as described above, the present invention was applied to the power converters100,200,300,400,500, and600for the overhead line-type electric railway vehicle10(or410) that is driven using power from the overhead line2. However, the present invention is not limited to this example. The present invention may also be applied to a power converter for a third rail-type railway vehicle10(or410) in which a third rail for supplying power is arranged separately but parallel to the running rails and a collector shoe arranged on the vehicle body11side contacts the third rail and collects power therefrom.

Moreover, in Embodiments 1 to 6 as described above, the present invention was applied to the power converters100,200,300,400,500, and600for the overhead line-type electric railway vehicle10(or410) that is driven using power from the overhead line2. However, the present invention is not limited to this example. In other words, the present invention may also be applied to heat sink equipment in a diesel railcar in which a diesel engine is used as a direct source of driving power or to dissipate heat from a power converter for a railway vehicle10(or410) in a diesel-electric railcar or the like in which a diesel engine is used to generate power for rotating the induction motors14.