Power conversion equipment for railway vehicles

Abstract

To provide a power conversion device for a railway vehicle capable of making traveling wind easily flow into a cooling fin arranged in a recessed part of a housing for the power conversion device.SOLUTION: A power conversion device 100 includes: a housing 10, which is mounted on a lower part 101b of a railway vehicle main body 101a, storing a power conversion part 1 in its inside, and provided with a recessed part 2 recessed inward; and a plurality of plate-like cooling fins 3, which are provided in the recessed part 2 so as to extend along a traveling direction (a direction of the flow of cooling air) of a railway vehicle main body 101a with intervals, and cool the power conversion part 1 by the traveling wind of the railway vehicle main body 101a. The power conversion device 100 includes a protrusion part 4 which is provided on an upstream side of the traveling wind of the cooling fins 3 on a surface 21a of the housing 10 in the vicinity of the recessed part 2 and protrudes toward the side opposite to the recessed direction of the recessed part 2.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a power converter for a railway vehicle, and more particularly to a power converter for a railway vehicle that is provided with cooling fins that cool a power converter unit by airflow caused by running the vehicle. [Background technology]

[0002] BACKGROUND ART Conventionally, a power conversion device for a railway vehicle is known that is provided with cooling fins that cool a power conversion unit by wind generated by running the vehicle (see, for example, Patent Document 1).

[0003] The power conversion device for railway vehicles described in Patent Document 1 above includes a heat dissipation portion of a cooler that is provided so as to protrude downward and outward from the outer circumferential surface of the power conversion device main body. The cooler is attached to a recessed portion of the power conversion device main body. The heat dissipation portion includes a plurality of heat dissipation fins that extend approximately parallel to the direction of travel of the railway vehicle. The recessed portion is provided so as to be recessed upward in the bottom surface of the power conversion device main body. The wind generated by the movement of the railway vehicle flows into the cooling fins arranged in the recessed portion as cooling wind, thereby dissipating heat generated in the power conversion device to the atmosphere. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-48533 Summary of the Invention [Problem to be solved by the invention]

[0005] In the power converter for railway vehicles described in Patent Document 1, heat dissipation fins (cooling fins) are attached to a recessed portion recessed upward on the bottom surface of the power converter main body (power converter housing). In this case, the upward recession of the recessed portion rapidly expands the flow path through which the running wind flows between the ground and the railway vehicle. This makes it difficult for the running wind to enter the recessed portion and instead flows below the recessed portion (heat dissipation fins). In this case, a difference in wind speed occurs between the inside and outside (the ground side) of the recessed portion, causing the central axis to extend along the sleeper direction, resulting in the formation of an air vortex in the recessed portion, which can cause air stagnation (retention). When a vortex occurs in the recessed portion, the running wind is prevented from flowing into the heat dissipation fins. Therefore, there is a need for a power converter for railway vehicles that can easily allow the running wind to flow into the heat dissipation fins (cooling fins) arranged in the recessed portion of the power converter housing.

[0006] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a power conversion device for a railway vehicle that can make it easier for running wind to flow into cooling fins arranged in a recessed portion of the power conversion device housing. [Means for solving the problem]

[0007] In order to achieve the above object, a railway vehicle power conversion device according to a first aspect of the present invention includes a power conversion unit casing that is attached to a lower part of a railway vehicle body, that houses a power conversion unit therein, and that is provided with a recessed portion that is recessed on the inside, a plurality of plate-shaped cooling fins that extend in the direction of travel of the railway vehicle body and are arranged at intervals from one another in the recessed portion, and that cool the power conversion unit with airflow from the railway vehicle body as it travels, and a plurality of cooling fins that are arranged on a surface of the power conversion unit casing near the recessed portion, upstream of the airflow from the airflow, and that overlap with the cooling fins when viewed from the direction of travel. Near the end of the recess in the direction of travel and a protrusion provided on the recessed portion and protruding in the opposite direction to the recessed direction of the recessed portion. Note that the term "vicinity of the recessed portion" means both the recessed portion itself and the area near the recessed portion.

[0008] This invention No. 1 In the power converter for a railway vehicle according to the above aspect, as described above, a protrusion is provided on the surface of the power converter housing near the recessed portion, upstream of the cooling fin in the flow of airflow caused by the running of the vehicle, and protruding in the opposite direction to the recessed portion. This allows the protrusion to change the flow direction of the running airflow, thereby causing turbulence in the flow of the running airflow. As a result, the turbulence in the flow of the running airflow can reduce air vortices that cause air stagnation (retention) in the recessed portion. This prevents air vortices generated in the recessed portion from hindering the running airflow from flowing into the cooling fin. As a result, the running airflow can be more easily guided into the cooling fins arranged in the recessed portion at the bottom of the railway vehicle body. Furthermore, by making it easier for the running airflow to flow into the cooling fins, the cooling efficiency of the power converter by the cooling fins can be improved.

[0009] Furthermore, by providing the protrusions on the power conversion unit housing, the power conversion unit housing can be removed from the railcar body to perform maintenance on the protrusions, which makes maintenance of the protrusions easier than when the power conversion unit housing is attached to the railcar body.

[0010] the above No. 1 In the power converter for a railway vehicle according to the above aspect, preferably, the protrusion has a shape that generates a swirling flow downstream of the protrusion. With this configuration, by generating a swirling flow in the recessed portion, it is possible to generate turbulence in the flow so that the air in the recessed portion is stirred by the swirling flow, thereby effectively reducing the air vortex generated in the recessed portion. As a result, it is possible to more easily allow the airflow generated by the running of the vehicle to flow into the cooling fins. This further improves the cooling efficiency of the power converter by the cooling fins.

[0011] In this case, the protruding portion preferably includes a first protrusion having a pair of first surfaces extending so as to intersect with the surface of the power conversion unit housing near the recessed portion, and a second surface provided so as to connect the pair of first surfaces, and extending along the traveling direction and having a shape tapering toward the downstream of the traveling wind. With this configuration, the tapered shape of the first protrusion makes it easier for the traveling wind flowing along the pair of first surfaces of the first protrusion to intersect with each other at the tip ends of the pair of first surfaces, thereby easily generating a swirling flow.

[0012] In the power converter for a railway vehicle in which the protrusion has a pair of first and second surfaces, preferably, the pair of first surfaces are provided so as to gradually approach each other downstream of the running wind, and the second surface connects the pair of first surfaces and has a flat surface shape. With this configuration, a swirling flow can be more easily generated by both the speed difference between the running wind flowing along the second surface and the pair of first surfaces, and the angle difference between the running wind flowing along one of the pair of first surfaces and the other of the pair of first surfaces and the running wind flowing along the second surface.

[0013] the above No. 1 In the power converter for a railway vehicle according to the above aspect, preferably, the recessed portion is provided on the bottom surface of the power converter housing, and the protrusion is provided so as to protrude downward from the bottom surface of the power converter housing near the recessed portion when the power converter housing is attached to the bottom of the railway vehicle body. With this configuration, the protrusion can make it easier for the running wind flowing along the bottom side of the power converter housing to flow into the cooling fins arranged in the recessed portion.

[0014] the above No. 1In the power converter for a railway vehicle according to this aspect, preferably, the recessed portion is provided on a side surface of the power converter housing, and the protrusion is provided so as to protrude laterally from the side surface of the power converter housing near the recessed portion when the power converter housing is attached to the lower part of the railway vehicle body. This configuration makes it easier for running wind flowing along the side surface of the power converter housing to flow into the cooling fins arranged in the recessed portion. Furthermore, since it is easier for workers to perform maintenance work on the side surface of the power converter housing than on the bottom surface of the power converter housing, it is possible to facilitate maintenance of the protrusion by workers.

[0015] the above No. 1 In the power conversion device for a railway vehicle according to the above aspect, the protrusions are preferably provided on both sides of the cooling fin in the running direction of the recessed portion. With this configuration, the protrusions can be disposed upstream of the cooling fin regardless of the running direction of the railway vehicle body.

[0016] In this case, preferably, the recessed portion includes a flat portion provided at the center of the recessed portion in the running direction of the railway vehicle body, on which the cooling fins are arranged, and a pair of inclined surface portions provided adjacent to both the upstream and downstream sides of the flat portion in the running wind, and the protrusions are provided near each of the pair of inclined surface portions. With this configuration, the protrusions can disrupt the flow of the running wind near each of the pair of inclined surface portions. Note that the term "near the inclined surface portions" means both the inclined surface portions themselves and the areas near the inclined surface portions.

[0017] In the power converter for a railway vehicle, in which the recessed portion includes a flat portion and a pair of inclined surface portions, preferably, at least a portion of the protrusion is provided near the end of the inclined surface portion opposite the flat portion. With this configuration, the flow of the running wind can be disturbed by at least a portion of the protrusion near the end of the inclined surface portion. Furthermore, the vicinity of the end of the inclined surface portion is a portion where the shape of the power converter housing changes, and therefore the flow of the running wind is likely to change. Thus, by providing at least a portion of the protrusion at the end where the flow of the running wind is likely to change, the flow of the running wind can be more effectively changed. As a result, the flow of the running wind can be more effectively disturbed. Note that the vicinity of the end of the inclined surface portion includes both the end of the inclined surface portion itself and the portion near the end of the inclined surface portion.

[0018] In the power converter for a railway vehicle, wherein the recessed portion includes a flat portion and a pair of inclined surface portions, preferably, the protrusion is at least partially provided on the surface of the inclined surface portion, extends in the running direction, and Driving wind The protrusions on the surface of the inclined surface portion have a shape in which the height of the protrusions increases toward the downstream side of the inclined surface portion. With this configuration, the downstream portion of the protrusions is positioned closer to the lower side of the recessed portion, so that the flow of the running wind flowing below the recessed portion can be easily disrupted.

[0019] In the power converter for a railway vehicle according to the above aspect, preferably, the protrusions are arranged in a row in the direction in which the cooling fins are arranged in a second region adjacent to the first region in which the cooling fins are arranged. With this configuration, it is possible to suppress unevenness in the amount of airflow flowing into the cooling fins in the direction in which the cooling fins are arranged, compared to when only one protrusion is provided.

[0020] In this case, preferably, the protrusion includes a second protrusion that is provided at an end of the second region in the direction in which the protrusions are arranged, extends along the traveling direction, and has a shape that tapers toward the downstream of the traveling wind. With this configuration, the second protrusion can change the flow of the traveling wind at the end side of the second region in the direction in which the protrusions are arranged.

[0021] In the power converter for a railway vehicle, the protrusions have a shape that generates a swirling flow, and preferably the protrusions have a curved shape that does not have any sharp corners. With this configuration, stress is less likely to concentrate on a curved shape than on a sharp corner, so that localized concentration of stress on the protrusions can be suppressed.

[0022] In this case, the protrusion preferably has a semi-spherical shape. With this configuration, the entire protrusion has a curved shape, which can further prevent stress from concentrating locally on the protrusion.

[0023] In the power converter for railway vehicles in which the protrusion has a curved shape, the protrusion having a curved shape is preferably formed integrally with the surface of the power converter housing near the recess by press working. This configuration prevents stress from concentrating locally on the protrusion, thereby preventing stress-induced damage to the protrusion when the surface and the protrusion are integrally formed. Furthermore, since the surface and the protrusion are integrally formed, the protrusion can be prevented from falling off the surface. Furthermore, the number of parts in the power converter for railway vehicles can be reduced compared to when the protrusion is provided separately from the surface. In addition, in order to achieve the above object, a power conversion device for a railway vehicle according to a second aspect of the present invention comprises a power conversion unit casing that is attached to the bottom of the railway vehicle body, houses the power conversion unit inside, and has a recessed portion that is recessed on the inside; a plurality of plate-shaped cooling fins that extend in the recessed portion along the running direction of the railway vehicle body and are arranged at intervals from each other, and cool the power conversion unit with the wind from the running of the railway vehicle body; and a protrusion that is provided on the surface of the power conversion unit casing near the recessed portion and on the upstream side of the running wind from the cooling fins, and protrudes on the opposite side to the recessed direction of the concave portion, and the protrusion has a shape that generates a swirling flow downstream of the running wind from the protrusion and upstream of the running wind from the cooling fins. [Effects of the Invention]

[0024] According to the present invention, as described above, it is possible to make it easier for the airflow from traveling to flow into the cooling fins arranged in the recessed portion of the power converter housing. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a schematic side view showing a railway vehicle according to a first embodiment. [Figure 2] 1 is a cross-sectional view taken along the traveling direction of a power conversion device according to a first embodiment. [Figure 3] 1 is a perspective view of a power conversion device according to a first embodiment, viewed from below. [Figure 4] FIG. 2 is a bottom view of the power conversion device according to the first embodiment. [Figure 5] FIG. 3 is an enlarged perspective view of the protrusion according to the first embodiment, as viewed from below. [Figure 6] FIG. 4 is an enlarged bottom view of a first projection according to the first embodiment. [Figure 7] FIG. 4 is an enlarged bottom view of a second projection according to the first embodiment. [Figure 8] FIG. 3 is a cross-sectional view taken along line 900-900 in FIG. 2. [Figure 9] FIG. 10 is a cross-sectional view of a power converter according to a second embodiment taken along the direction of a sleeper. [Figure 10] FIG. 10 is a cross-sectional view taken along line 910-910 in FIG. 9. [Figure 11] FIG. 10 is a side view of a recessed portion according to a second embodiment. [Figure 12] FIG. 11 is a cross-sectional view of a power converter according to a third embodiment taken along the sleeper direction. [Figure 13] FIG. 10 is an enlarged view of the vicinity of a recessed portion according to a fourth embodiment. [Figure 14] FIG. 11 is an enlarged perspective view of a protrusion according to a fourth embodiment, as viewed from below. [Figure 15] FIG. 14 is an enlarged view of the vicinity of the protrusion in FIG. 13. [Figure 16] FIG. 10 is a cross-sectional view taken along the sleeper direction of the power converter according to the first modified example of the second embodiment. [Figure 17] FIG. 10 is a cross-sectional view taken along the sleeper direction of a power converter according to a second modification of the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0026] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

[0027] [First embodiment] The configuration of a power converter 100 according to a first embodiment will be described with reference to Figures 1 to 8. The power converter 100 is an example of the "power converter for railway vehicles" in the claims.

[0028] As shown in FIG. 1, the power conversion device 100 includes a power conversion unit 1 such as an inverter. The power conversion device 100 also includes a housing 10 that is attached to a lower portion 101b of a railway vehicle body 101a of a railway vehicle 101, houses the power conversion unit 1 therein, and has a recessed portion 2 (see FIG. 2) recessed inward. The housing 10 is attached to the lower portion 101b of the railway vehicle body 101a with a plurality of metal fittings 102 (see FIG. 2). The recessed portion 2 is also provided on a bottom surface 11 of the housing 10. The housing 10 is an example of a "housing for a power conversion unit" as defined in the claims.

[0029] The railway vehicle 101 is a railway vehicle that runs in a formation of multiple cars. As shown in FIG. 1, the railway vehicle 101 is configured to run on power supplied from an overhead line 103 as an AC or DC power source. For example, the railway vehicle 101 is a conventional train or a high-speed railway vehicle. In the following, the railway vehicle 101 will be described using a high-speed railway vehicle as an AC electric vehicle as an example. The railway vehicle 101 is also provided with a pantograph 101c and electrical equipment (not shown) such as a transformer, an induction motor, and air conditioning equipment. The pantograph 101c receives power from the overhead line 103. The power conversion unit 1 converts the AC voltage from the pantograph 101c, which has been transformed by the transformer, into a desired three-phase AC voltage and frequency, and outputs the voltage to the induction motor, air conditioning equipment, etc.

[0030] The housing 10 is provided so as to extend from near an end 101e (see FIG. 8) on one side in the Y direction (sleeper direction) of the railway vehicle body 101a to near an end 101f (see FIG. 8) on the other side.

[0031] As shown in FIG. 2, the power conversion device 100 includes a plurality of plate-shaped cooling fins 3 arranged in the recessed portion 2. Arranging the cooling fins 3 in the recessed portion 2 can prevent the cooling fins 3 from exceeding the installation limit of the railway vehicle 101. The plurality of cooling fins 3 extend along the running direction (X direction) of the railway vehicle body 101a and are arranged at intervals from one another in the sleeper direction (Y direction). The plurality of cooling fins 3 cool the power conversion unit 1 by wind generated by the running of the railway vehicle body 101a. Each of the plurality of cooling fins 3 is arranged to protrude from the lower portion 101b of the railway vehicle body 101a to the outside (atmosphere side) of the railway vehicle body 101a. The sleeper direction (Y direction) is perpendicular to the running direction (X direction).

[0032] The recessed portion 2 includes a flat portion 20 on which the cooling fins 3 are arranged. The flat portion 20 is provided in the center of the recessed portion 2 (and the housing 10) in the running direction (X direction) of the railway vehicle body 101a. The recessed portion 2 also includes a pair of inclined surface portions 21 that are arranged adjacent to both the upstream side and downstream side of the flat portion 20 in the running wind. In other words, the bottom surface 11 (see FIG. 1) of the housing 10 includes the flat portion 20 and the pair of inclined surface portions 21.

[0033] Here, in the first embodiment, the power conversion device 100 includes a protrusion 4 that is provided on the surface of the housing 10 near the recessed portion 2 and on the upstream side of the cooling fin 3 in the direction of the running wind, and that protrudes in the opposite direction to the recessed direction of the recessed portion 2. Specifically, the recessed portion 2 is recessed upward (toward the Z1 side). That is, the protrusion 4 is provided so as to protrude downward (toward the Z2 side) from the bottom surface 11 of the housing 10 near the recessed portion 2 when the housing 10 is attached to the lower part 101b of the railway vehicle body 101a. Furthermore, the protrusion 4 is provided so as not to protrude outside the recessed portion 2, but so that the entire protrusion 4 is housed inside the recessed portion 2. Furthermore, the protrusion 4 is formed integrally with the housing 10. The protrusion 4 is made of metal.

[0034] In the first embodiment, as shown in Fig. 3, the protrusions 4 are arranged in a row in a region S2 adjacent to the region S1 where the cooling fins 3 are provided, along the direction in which the cooling fins 3 are arranged (the Y direction). Specifically, the region S1 where the cooling fins 3 are provided is arranged so as to be aligned with the region S2 where the protrusions 4 are provided in the X direction. The direction in which the cooling fins 3 are arranged is the sleeper direction. The region S1 and the region S2 are examples of the "first region" and the "second region" in the claims, respectively.

[0035] Specifically, two regions S1, each having a plurality of cooling fins 3, are arranged side by side along the Y direction (sleeper direction). Each of the two regions S1 is arranged so as to be sandwiched between regions S2 in the X direction (traveling direction). The plurality of protrusions 4 are arranged side by side at intervals in the region S2.

[0036] Two regions S1 aligned in the Y direction are separated by a first protrusion 50 provided between the regions S1. Two regions S2 aligned in the Y direction on both sides of the region S1 in the X direction are separated by a second protrusion 51 provided between the regions S2.

[0037] The protrusion portion 4 includes a first protrusion 40 and a second protrusion 41. A plurality of first protrusions 40 and a plurality of second protrusions 41 are provided in each of the plurality of regions S2. Specifically, a plurality of first protrusions 40 are provided in each of the plurality of regions S2, and two second protrusions 41 are provided so as to sandwich the plurality of first protrusions 40 provided in the Y direction from both sides in the Y direction. Note that in the following description, when the protrusion portion 4 is referred to, it is assumed that this is a feature common to the first protrusions 40 and the second protrusions 41.

[0038] In the first embodiment, the protrusions 4 are provided on each of the pair of inclined surface portions 21. That is, the surface of the housing 10 on which the protrusions 4 are arranged is the surface 21a provided on the inclined surface portion 21. Specifically, the entire first protrusion 40 is provided on the surface 21a of the inclined surface portion 21. The second protrusion 41 is provided so as to straddle the inclined surface portion 21 and the flat portion 20 (see FIG. 4). The protrusions 4 are provided directly on the inclined surface portion 21.

[0039] In the first embodiment, at least a portion of the protrusion 4 is provided near the end 21b of the inclined surface portion 21 opposite the flat portion 20. Specifically, the first protrusion 40 includes an end 40a of the first protrusion 40 opposite the flat portion 20, and is disposed on the inclined surface portion 21 so that the end 40a is provided on the end 21b of the inclined surface portion 21. The second protrusion 41 includes an end 41a of the second protrusion 41 opposite the flat portion 20, and is disposed so as to straddle the inclined surface portion 21 and the flat portion 20 so that the end 41a is provided on the end 21b of the inclined surface portion 21. Although FIG. 2 illustrates the end 21b of the inclined surface portion 21 as being angular, the end 21b of the inclined surface portion 21 may have an R-shape.

[0040] In the first embodiment, the protrusions 4 are provided on both sides of the cooling fin 3 in the running direction of the recessed portion 2. In other words, the protrusions 4 are provided on both the upstream and downstream sides of the running wind with respect to the cooling fin 3. The arrangement and configuration (number, etc.) of the protrusions 4 are symmetrical on the X1 side and the X2 side with respect to the cooling fin 3 (region S1) as the center when viewed from below (Z2 side).

[0041] In the first embodiment, the protrusions 4 are at least partially provided on the surface 21a of the inclined surface portion 21, extend in the running direction, and have a shape in which the height (h1, h2) of the portion of the protrusions 4 provided on the surface 21a of the inclined surface portion 21 increases downstream in the running direction. Specifically, the height h1 of the first protrusions 40 is zero at the end 40a of the first protrusions 40 and gradually increases downstream. The height h2 of the second protrusions 41 is zero at the end 41a of the second protrusions 41. The height h2 of the portion 410 (see FIG. 4) of the second protrusions 41 provided on the inclined surface portion 21 gradually increases downstream. The height h2 of the portion 411 (see FIG. 4) of the second protrusions 41 provided on the flat portion 20 is constant.

[0042] In the first embodiment, the first projection 40 has a pair of surfaces 40b and 40c, and extends in the traveling direction and tapers toward the downstream side of the traveling wind. The pair of surfaces 40b extend so as to intersect with the surface 21a of the housing 10 near the recessed portion 2. The surface 40c is provided so as to connect the pair of surfaces 40b to each other. Specifically, as shown in FIG. 4, the surface 40c has a substantially isosceles triangular shape in a bottom view (viewed from the Z2 direction) with the tip 40d of the first projection 40 on the downstream side of the traveling wind as its vertex. The surface 40b has a right-angled triangular shape tapering toward the upstream side of the traveling wind when viewed from the side (see FIG. 5). The surfaces 40b and 40c are the side surface and the bottom surface of the first projection 40, respectively. The surfaces 40b and 40c are examples of the "first surface" and the "second surface" in the claims.

[0043] Specifically, the pair of surfaces 40b are provided so as to gradually approach each other toward the downstream of the running wind. Furthermore, surface 40c connects the pair of surfaces 40b and has a flat surface shape. Specifically, the pair of surfaces 40b are connected to each other by tip portions 40d of the first projections 40. Tip portions 40d are not formed in a pin-angle shape, but are formed in a flat shape having a predetermined area. In other words, tip portions 40d are chamfered. Furthermore, corner portions 40e (see FIG. 5) between surfaces 40b and 40c are also not formed in a pin-angle shape, but are formed in a flat shape having a predetermined area (chamfered). Furthermore, surface 40c is a flat surface extending in a horizontal direction (a surface extending parallel to the ground).

[0044] 3, each of the pair of surfaces 40b of the first projection 40 is provided so as to extend downward (toward the Z2 direction) from the surface 21a of the inclined surface portion 21. That is, each of the pair of surfaces 40b is provided so as to be perpendicular to the surface 40c of the first projection 40 that extends in the horizontal direction. Note that in the X direction, the position where the tip portion 40d of the first projection 40 is provided and the flat portion 20 where the cooling fin 3 is arranged are spaced apart from each other.

[0045] In the first embodiment, the second projections 41 are provided at the ends of the region S2 in the direction in which the protrusions 4 are arranged (Y direction), and extend along the traveling direction and have a shape that tapers toward the downstream of the traveling wind. Specifically, the second projections 41 are provided at both ends of the region S2 in the Y direction.

[0046] The second projection 41 has a surface 41b and a surface 41c. The surface 41b extends so as to intersect with the surface 21a of the inclined surface portion 21. The surface 41c is connected to the surface 41b and is a flat surface extending in a horizontal direction (a surface extending parallel to the ground). Specifically, as shown in FIG. 4, the surface 41c has a substantially right-angled triangular shape in a bottom view (seen from the Z2 direction), with the tip 41d of the projection 4 on the downstream side of the running wind as its vertex. The tip 41d is not formed in a pin-angle shape, but is formed in a flat shape (chamfered) having a predetermined area. Furthermore, the corner 41e (see FIG. 3) between the surfaces 41b and 41c is also not formed in a pin-angle shape, but is formed in a flat shape (chamfered) having a predetermined area.

[0047] Furthermore, surface 41b has a right-angled triangular shape (see FIG. 3) that tapers toward the upstream of the running wind when viewed from the side. Surfaces 41b and 41c are the side surface and bottom surface of second projection 41, respectively.

[0048] 4, the length L11 in the X direction of the first protrusion 40 is smaller than the length L12 in the X direction of the second protrusion 41. That is, the tip 41d of the second protrusion 41 is located closer to the cooling fin 3 than the tip 40d of the first protrusion 40. The position of the tip 41d of the second protrusion 41 in the Y direction is shifted from the position of the cooling fin 3 in the Y direction.

[0049] 5 and 6, the protrusion 4 has a shape that generates a swirling flow downstream of the protrusion 4. Specifically, in the first protrusion 40, a traveling wind f1 flowing along one of the pair of surfaces 40b, a traveling wind f2 flowing along the other of the pair of surfaces 40b, and a traveling wind f3 flowing along the surface 40c intersect with each other on the downstream side (the tip end 40d side) of the first protrusion 40 (see FIG. 6), thereby forming a swirling flow F1. The swirling flow F1 is a swirling flow whose rotation axis extends along the X direction.

[0050] 7, a swirling flow F2 is formed by a traveling wind f4 flowing along the surface 41b and a traveling wind f5 flowing along the surface 41c intersecting each other on the downstream side (the tip end 41d side) of the second protrusion 41. The swirling flow F2 is a swirling flow whose rotation axis extends along the X direction.

[0051] (Effects of the first embodiment) In the first embodiment, the following effects can be obtained.

[0052] In the first embodiment, as described above, the power conversion device 100 is configured such that the protrusion 4 is provided on the surface 21a of the housing 10 near the recessed portion 2 and upstream of the cooling fin 3 in the direction of the running wind, protruding in the opposite direction to the recessed direction of the recessed portion 2. This allows the protrusion 4 to change the flow direction of the running wind, thereby causing turbulence in the flow of the running wind. As a result, the turbulence in the flow of the running wind can reduce air vortices that cause air stagnation (retention) in the recessed portion 2. This prevents air vortices that occur in the recessed portion 2 from preventing the running wind from flowing into the cooling fin 3. As a result, the running wind can be more easily guided into the cooling fin 3 that is disposed in the recessed portion 2 in the lower portion 101b of the railcar body 101a. Furthermore, the ease with which the running wind can flow into the cooling fin 3 can improve the cooling efficiency of the power conversion unit 1 by the cooling fin 3.

[0053] Furthermore, since the housing 10 is provided with the protrusions 4, the housing 10 can be removed from the railway vehicle body 101a to perform maintenance on the protrusions 4. This makes maintenance of the protrusions 4 easier than when maintenance is performed on the protrusions 4 while the housing 10 is attached to the railway vehicle body 101a.

[0054] Furthermore, in the first embodiment, as described above, the power conversion device 100 is configured so that the protrusions 4 have a shape that generates swirling flows (F1, F2) downstream of the protrusions 4. This generates swirling flows (F1, F2) in the recessed portions 2, which causes turbulence in the flow so that the air in the recessed portions 2 is stirred by the swirling flows (F1, F2), thereby effectively reducing the size of the air vortexes generated in the recessed portions 2. As a result, it becomes easier for the wind generated by running to flow into the cooling fins 3. This further improves the cooling efficiency of the power conversion unit 1 by the cooling fins 3.

[0055] Furthermore, in the first embodiment, as described above, the power converter 100 is configured to include the first protrusion 40, which has a pair of faces 40b extending so as to intersect with the surface 21a of the housing 10 near the recessed portion 2 and a face 40c provided so as to connect the pair of faces 40b, and which extends along the traveling direction and has a shape that tapers toward the downstream of the traveling wind, due to the tapered shape of the first protrusion 40. As a result, the traveling winds (f1, f2) flowing along the pair of faces 40b of the first protrusion 40 tend to intersect with each other at the tip ends of the pair of faces 40b, and therefore, a swirling flow F1 can be easily generated.

[0056] Furthermore, in the first embodiment, as described above, the pair of surfaces 40b are provided so as to gradually approach each other downstream of the running wind, and surface 40c connects the pair of surfaces 40b and has a flat surface shape, configuring power conversion device 100. This makes it possible to more easily generate swirling flow F1 due to both the speed difference between running wind f3 flowing along surface 40c and running wind (f1, f2) flowing along the pair of surfaces 40b, and the angle difference between running wind f1 flowing along one of the pair of surfaces 40b, running wind f2 flowing along the other of the pair of surfaces 40b, and running wind f3 flowing along surface 40c.

[0057] Furthermore, in the first embodiment, as described above, the power conversion device 100 is configured so that the protrusions 4 protrude downward from the bottom surface 11 of the housing 10 near the recessed portion 2 when the housing 10 is attached to the lower portion 101b of the railway vehicle body 101a. This makes it easier for the protrusions 4 to direct the running wind flowing along the bottom surface 11 side of the housing 10 into the cooling fins 3 arranged in the recessed portion 2.

[0058] Furthermore, in the first embodiment, as described above, the power conversion device 100 is configured so that the protrusions 4 are provided on both sides of the cooling fins 3 in the running direction of the recessed portions 2. This allows the protrusions 4 to be located upstream of the cooling fins 3 regardless of the running direction of the railway vehicle body 101a.

[0059] Furthermore, in the first embodiment, as described above, the power conversion device 100 is configured so that the protrusions 4 are provided on each of the pair of inclined surface portions 21. This allows the protrusions 4 to disrupt the flow of running wind on each of the pair of inclined surface portions 21.

[0060] Furthermore, in the first embodiment, as described above, the power converter 100 is configured so that at least a portion of the protrusion 4 is provided on the end 21b of the inclined surface portion 21 opposite the flat portion 20. This allows at least a portion of the protrusion 4 to disrupt the flow of the running wind at the end 21b of the inclined surface portion 21. Furthermore, the end 21b of the inclined surface portion 21 is a portion where the shape of the housing 10 changes, and therefore the flow of the running wind is likely to change. Thus, by providing at least a portion of the protrusion 4 on the end 21b where the flow of the running wind is likely to change, the flow of the running wind can be changed more effectively. As a result, the flow of the running wind can be disrupted more effectively.

[0061] Furthermore, in the first embodiment, as described above, the power conversion device 100 is configured so that the protrusions 4 extend in the traveling direction and have a shape in which the heights (h1, h2) of the portions of the protrusions 4 provided on the surface 21a of the inclined surface portion 21 increase toward the downstream side in the traveling direction. This positions the downstream portions of the protrusions 4 close to the lower side of the recessed portion 2, so that the flow of the traveling wind flowing below the recessed portion 2 can be easily disrupted.

[0062] Furthermore, in the first embodiment, as described above, the power conversion device 100 is configured so that a plurality of protrusions 4 are arranged in a row along the direction in which the plurality of cooling fins 3 are arranged in the region S2 adjacent to the region S1 in which the plurality of cooling fins 3 are arranged. This makes it possible to suppress bias in the amount of traveling airflow flowing into the cooling fin 3 in the direction in which the plurality of cooling fins 3 are arranged, compared to when only one protrusion 4 is provided.

[0063] Furthermore, in the first embodiment, as described above, the power conversion device 100 is configured so that the protrusion 4 is provided at the end of the region S2 in the direction in which the multiple protrusions 4 are arranged, and includes the second protrusion 41 that extends along the traveling direction and has a shape that tapers toward the downstream of the traveling wind. This allows the second protrusion 41 to change the flow of the traveling wind at the end side of the region S2 in the direction in which the multiple protrusions 4 are arranged.

[0064] [Second embodiment] A second embodiment will be described with reference to Figures 9 to 11. In this second embodiment, unlike the first embodiment in which the recessed portion 2 is provided on the bottom surface 11 of the housing 10, a recessed portion 12 is provided on the side surface 111 of the housing 110. Note that the same components as those in the first embodiment are denoted by the same reference numerals in the drawings, and their description will be omitted.

[0065] As shown in Fig. 9, the power conversion device 200 includes a housing 110 having a recessed portion 12 recessed inward. The recessed portion 12 is provided on a side surface 111 of the housing 110. The housing 110 is an example of a "housing for a power conversion unit" in the claims. The power conversion device 200 is also an example of a "power conversion device for a railway vehicle" in the claims.

[0066] The housing 110 is provided near an end 101e on one side (for example, the Y2 side) in the Y direction (sleeper direction) of the railway vehicle body 101a. The side surface 111 of the housing 110 is the side surface on the Y2 side of the housing 110. That is, when the railway vehicle body 101a is viewed from the outside (the Y2 side), the recessed portion 12 is exposed.

[0067] As shown in FIG. 10 , the recessed portion 12 includes a flat portion 120 on which the cooling fins 3 are arranged. The recessed portion 12 also includes a pair of inclined surface portions 121 arranged adjacent to both the upstream side and downstream side of the flat portion 120 in the direction of the running wind. That is, the side surface 111 of the housing 110 includes the flat portion 120 and the pair of inclined surface portions 121. The side surface 111 (the flat portion 120 and the inclined surface portions 121) is also provided so as to extend along the vertical direction. That is, the side surface 111 is provided so as to extend perpendicular to the ground. The cooling fins 3 are provided so as to extend horizontally.

[0068] The power conversion device 200 includes a protrusion 14. The protrusion 14 is provided on the surface 121a of the inclined surface portion 121. The protrusion 14 includes a first protrusion 140 and a second protrusion 141. The first protrusion 140 and the second protrusion 141 have the same configuration as the first protrusion 40 and the second protrusion 41 of the first embodiment, respectively, and therefore detailed description thereof will be omitted. Note that in the following description, when the protrusion 14 is mentioned, it is assumed to be a feature common to the first protrusion 140 and the second protrusion 141.

[0069] Here, in the second embodiment, protrusion 14 is provided so as to protrude laterally from side surface 111 of housing 110 near recessed portion 12 when housing 110 is attached to lower portion 101b (see FIG. 9) of railway vehicle body 101a. In other words, protrusion 14 is provided so as to protrude toward the outside (Y2 side) of railway vehicle body 101a in the sleeper direction (Y direction).

[0070] 11, in the second embodiment, the protrusions 14 are arranged in a row in a region S12 adjacent to the region S11 where the plurality of cooling fins 3 are provided, along the direction in which the plurality of cooling fins 3 are arranged (Z direction). Specifically, the region S11 where the cooling fins 3 are provided is arranged so as to be aligned with the region S12 where the protrusions 14 are provided in the X direction. The region S11 and the region S12 are examples of the "first region" and the "second region" in the claims, respectively.

[0071] Furthermore, in each of the plurality of regions S12, a plurality of first protrusions 140 are provided in a row, and two second protrusions 141 are provided so as to sandwich the plurality of first protrusions 140 in a row in the Z direction.

[0072] The first protrusion 140 also has a pair of surfaces 140b and 140c. The pair of surfaces 140b extend so as to intersect with the surface 121a of the housing 110 near the recessed portion 12. One of the pair of surfaces 140b is provided so as to face upward (Z1 side). The other of the pair of surfaces 140b is provided so as to face downward (Z2 side). The surface 140c is provided so as to face the outside (Y2 side) of the railway vehicle body 101a in the sleeper direction (Y direction). The surfaces 140b and 140c are examples of the "first surface" and "second surface" in the claims, respectively.

[0073] Second projection 141 has surface 141b and surface 141c. Surface 141b extends so as to intersect with surface 121a of inclined surface portion 121. Surface 141b is provided so as to face upward (Z1 side) or downward (Z2 side). Surface 141c is provided so as to face the outside (Y2 side) of railway vehicle body 101a in the sleeper direction (Y direction).

[0074] The other configurations of the second embodiment are the same as those of the first embodiment.

[0075] (Effects of the second embodiment) In the second embodiment, the following effects can be obtained.

[0076] In the second embodiment, the power conversion device 200 is configured so that the protrusions 14 protrude laterally from the side surface 111 of the housing 110 near the recessed portion 12 when the housing 110 is attached to the lower portion 101b of the railway vehicle body 101a. This makes it easier for the running wind flowing along the side surface 111 of the housing 110 to flow into the cooling fins 3 arranged in the recessed portion 12. Furthermore, since it is easier for workers to perform maintenance work on the side surface 111 of the housing 110 than on the bottom surface side of the housing 110, it is possible to facilitate the workers' maintenance of the protrusions 14.

[0077] The other effects of the second embodiment are the same as those of the first embodiment.

[0078] [Third embodiment] A third embodiment will be described with reference to Fig. 12. In this third embodiment, unlike the second embodiment in which the cooling fins 3 themselves are directly attached to the recessed portions 12, the cooling fins 13 are attached to the heat pipes 30. Note that the same components as those in the second embodiment are denoted by the same reference numerals in the drawings, and their description will be omitted.

[0079] 12, the power converter 300 includes cooling fins 13 and a heat pipe 30. The power converter 300 is an example of the "power converter for railway vehicles" in the claims.

[0080] The heat pipe 30 is provided so as to protrude from the side surface 111 of the recessed portion 12 (the surface corresponding to the flat portion 120 of the recessed portion 12; see FIG. 10 of the second embodiment) toward the outside (Y2 side) of the railway vehicle 101. The heat pipe 30 is also provided so as to incline upward relative to the horizontal direction. This allows the refrigerant vaporized within the heat pipe 30 to move to the tip side (Y2 side) of the heat pipe 30, then liquefy and return to the base side (Y1 side). As a result, the refrigerant is circulated within the heat pipe 30. The refrigerant has the role of transporting heat generated in the power conversion unit 1 into the heat pipe 30.

[0081] The plurality of cooling fins 13 are attached to the heat pipes 30. Specifically, the heat pipes 30 are provided so as to penetrate the plate-shaped cooling fins 13, thereby fixing the cooling fins 13 to the heat pipes 30. Each of the plurality of cooling fins 13 is provided so as to extend along the running direction (X direction) and the up-down direction (Z direction) of the railway vehicle body 101a. The plurality of cooling fins 13 are also arranged at intervals from one another in the sleeper direction (Y direction).

[0082] This makes it easier for the protrusion 14 (see Figure 10 of the second embodiment, etc.) to allow the wind from traveling to flow into the cooling fins 3 arranged in the recessed portions 12, thereby making it possible to efficiently cool the heat pipes 30.

[0083] The other configurations of the third embodiment are the same as those of the second embodiment, and the other effects of the third embodiment are the same as those of the second embodiment.

[0084] [Fourth embodiment] A fourth embodiment will be described with reference to Figures 13 to 15. Unlike the first embodiment in which the tapered protrusions 4 are provided, the fourth embodiment is provided with protrusions 34 having curved surfaces. Note that the same components as those in the first embodiment are denoted by the same reference numerals in the drawings, and their description will be omitted.

[0085] The configuration of a power converter 600 according to the fourth embodiment will be described with reference to Figures 13 to 15. The power converter 600 is an example of the "power converter for railway vehicles" in the claims.

[0086] 13, the power converter 600 includes a housing 610 having a recessed portion 2 recessed inward. The housing 610 is an example of the "housing for the power converter" in the claims.

[0087] The power converter 600 includes a protrusion 34. Specifically, the protrusion 34 is disposed on the inclined surface portion 21. An end 34a of the protrusion 34 opposite to the flat portion 20 is provided on an end 21b of the inclined surface portion 21.

[0088] In the fourth embodiment, the protrusion 34 has a curved surface shape without any sharp corners, as shown in Fig. 11. Specifically, the surface of the protrusion 34 does not include any flat portions or corners, and is curved overall.

[0089] Specifically, the protrusion 34 has a hemispherical shape. Note that the hemispherical shape does not only mean a shape obtained by cutting half of a sphere, but also has a broader meaning including a shape obtained by cutting other than half of a sphere (for example, two-thirds of a sphere).

[0090] Furthermore, the protrusions 34 have a shape that generates a swirling flow F3 downstream of the protrusions 34. Specifically, the swirling flow F3 is formed when the flowing winds f11 flowing along the surfaces of the protrusions 34 intersect with each other downstream of the protrusions 34. The swirling flow F3 is a swirling flow whose rotation axis extends along the X direction.

[0091] In the fourth embodiment, the curved protrusion 34 is formed integrally with the surface 21a of the inclined surface portion 21 by press working. Specifically, as shown in Fig. 15, the protrusion 34 includes an outer peripheral edge 34b formed during press working of the protrusion 34. The outer peripheral edge 34b has an R-shape.

[0092] The protrusion 34 is provided such that its lower end 34c protrudes from the recessed portion 2. The lower end 34c of the protrusion 34 is provided above (on the Z1 side of) the outfitting limit P1.

[0093] In addition, when a device other than the power conversion device 600 is adjacent to the housing 610 in the X direction, it is preferable that the lower end of the device be located closer to the railway vehicle main body 101a (to the Z1 side in the fourth embodiment) than position P2 in the Z direction of the end 34a of the protrusion 34.

[0094] The other configurations of the fourth embodiment are the same as those of the first embodiment.

[0095] (Effects of the fourth embodiment) In the fourth embodiment, the following effects can be obtained.

[0096] In the fourth embodiment, as described above, the power conversion device 600 is configured so that the protrusions 34 have a curved shape without any sharp corners. This makes it possible to prevent stress from concentrating locally on the protrusions 34, since stress is less likely to concentrate on a curved shape than on sharp corners.

[0097] In the fourth embodiment, as described above, the power converter 600 is configured so that the protrusions 34 have a hemispherical shape. This makes the entire protrusions 34 have a curved shape, which can further prevent stress from concentrating locally on the protrusions 34.

[0098] In the fourth embodiment, as described above, the power converter 600 is configured so that the curved protrusions 34 are formed integrally with the surface 21a near the recessed portion 2 by press working. This prevents stress from concentrating locally on the protrusions 34, thereby preventing the protrusions 34 from being damaged due to stress when the surface 21a and the protrusions 34 are integrally formed. Furthermore, because the surface 21a and the protrusions 34 are integrally formed, the protrusions 34 are prevented from falling off the surface 21a. Furthermore, the number of parts of the power converter 600 can be reduced compared to when the protrusions 34 are provided separately from the surface 21a.

[0099] The other effects of the fourth embodiment are the same as those of the first embodiment.

[0100] (Variation) The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than the description of the above embodiments, and further includes all modifications (variations) within the meaning and scope of the claims.

[0101] For example, in the second embodiment, the side surface 111 of the housing 110 on which the recessed portion 12 is provided is provided so as to extend along the vertical direction, but the present invention is not limited to this. The side surface of the housing on which the recessed portion is provided may be inclined with respect to the vertical direction.

[0102] Specifically, as shown in FIG. 16 , the housing 210 of the power converter 400 includes a side surface 211 that is inclined and curved relative to the vertical direction. The side surface 211 is provided with a recessed portion 22. The recessed portion 22 includes a flat portion 220 on which the cooling fins 23 are disposed, and a pair of inclined surface portions 221 disposed adjacent to both the upstream side and the downstream side of the flat portion 220 in the direction of the running wind. The flat portion 220 is provided so as to extend perpendicular to the ground. The side surface 211 of the housing 210 includes the flat portion 220 and the pair of inclined surface portions 221. The power converter 400 is an example of a "power converter for a railway vehicle" as claimed. The housing 210 is also an example of a "housing for a power converter" as claimed.

[0103] Furthermore, the length L1 in the Y direction of the cooling fins 23 increases toward the upper side (Z1 side) of the cooling fins 23. That is, the cooling fins 23 located toward the upper side (Z1 side) protrude further toward the Y2 side. Note that, in the second embodiment, the length of each of the cooling fins 23 may be the same as that shown in FIG. 16.

[0104] Furthermore, protrusions 24 including a first protrusion 240 and a second protrusion 241 are provided on both ends of the recessed portion 22 in the X direction.

[0105] Although FIG. 16 illustrates an example in which the flat portion 220 extends vertically, this is not limiting. Specifically, as illustrated in FIG. 17 , the housing 310 of the power converter 500 includes a flat portion 320 that is inclined relative to the vertical direction. The flat portion 320 is provided in a recessed portion 32 disposed on a side surface 311 of the housing 310. The recessed portion 32 includes a pair of inclined surface portions 321 disposed adjacent to both the upstream and downstream sides of the flat portion 320 in the direction of the running wind. That is, the side surface 311 of the housing 310 includes the flat portion 320 and the pair of inclined surface portions 321. The flat portion 320 is inclined upward toward the Y2 side. While FIG. 17 illustrates an example in which the lengths L2 of the multiple cooling fins 33 are equal to each other, the lengths L2 of the multiple cooling fins 33 may be different from each other. The power converter 500 is an example of a "railroad vehicle power converter" as defined in the claims. The housing 310 is an example of the "housing for a power converter" in the claims.

[0106] In addition, in the first to fourth embodiments, the protrusions 4 (14, 34) have a shape that generates a swirling flow (F1, F2, F3), but the present invention is not limited to this. The protrusions do not have to have a shape that generates a swirling flow as long as they have a shape that disturbs the flow of the wind generated by running.

[0107] In addition, in the first to fourth embodiments, the protrusions 4 (14, 34) extend in the traveling direction and taper downstream of the traveling wind, but the present invention is not limited to this. For example, the protrusions may have a semicircular shape when viewed from below. Furthermore, a pair of side surfaces of the protrusions may have a curved shape.

[0108] In the first embodiment, the surface 40c (second surface) of the first projection 40 is a flat surface extending in a horizontal direction (a surface extending parallel to the ground), but the present invention is not limited to this. For example, the surface 40c may be a surface that is inclined upward with respect to the ground.

[0109] In the first embodiment, the surface 40c (second surface) has a substantially isosceles triangular shape when viewed from below (from the Z2 direction), but the present invention is not limited to this. For example, the surface 40c may have a triangular shape other than an isosceles triangle. This may also be the case in the second and third embodiments.

[0110] In the first embodiment, each of the pair of surfaces 40b (first surfaces) is provided so as to be perpendicular to the surface 40c (second surface) of the first projection 40 extending in the horizontal direction, but the present invention is not limited to this. For example, the angle formed between each of the pair of surfaces 40b and surface 40c may be an acute angle or an obtuse angle. Furthermore, the angle formed between surface 41b and surface 41c of the second projection 41 may be an acute angle or an obtuse angle. This may also be the case in the second and third embodiments.

[0111] In addition, in the first to fourth embodiments, examples have been shown in which the protrusions 4 (14, 34) are provided directly on the inclined surface portion 21 (121), but the present invention is not limited to this. Protrusions may be provided indirectly on the inclined surface portion via a connecting portion.

[0112] In the first to fourth embodiments, the protrusions 4 (14, 34) are provided on both sides of the cooling fin 3 (13) in the running direction, but the present invention is not limited to this. The protrusions 4 (14, 34) may be provided on one side of the cooling fin in the running direction.

[0113] In addition, in the above first to third embodiments, an example was shown in which the portion of the protrusion 4 (14) provided on the inclined surface portion 21 has a shape in which the height (h1, h2) increases toward the downstream side in the traveling direction, but the present invention is not limited to this. For example, the height of the protrusion may decrease toward the downstream side, or may be the same at any position in the traveling direction. Furthermore, the height of the portion of the second protrusion 41 (141) provided on the flat portion 20 (120) may increase toward the downstream side of the traveling wind.

[0114] In the first embodiment, a plurality of protrusions 4 are arranged in the region S2 (second region) along the sleeper direction, but the present invention is not limited to this. Only one of the first protrusion 40 or the second protrusion 41 may be arranged in the region S2. This may also be the case in the second and third embodiments.

[0115] Furthermore, in the first to fourth embodiments, examples have been shown in which the railway vehicle 101 is a conventional train or a high-speed railway vehicle, but the present invention is not limited to this. For example, the railway vehicle may be a diesel railcar (a train equipped with an engine).

[0116] In addition, in the first to fourth embodiments, an example was shown in which the recessed portion 2 (12) was provided with a pair of inclined surface portions 21 (121), but the present invention is not limited to this. The recessed portion does not necessarily have to be provided with inclined surface portions.

[0117] In the first to fourth embodiments, the protrusions 4 (14, 34) are provided on the surface 21a (121a) of the recessed portion 2 (12), but the present invention is not limited to this. The protrusions 4 (14, 34) may be provided near the recessed portion 2 (12) and on the outside of the recessed portion 2 (12). The protrusions 4 (14, 34) may be provided so as to straddle both the outside and inside of the recessed portion 2 (12).

[0118] In addition, in the first to fourth embodiments, examples have been shown in which the protrusions 4 (14, 34) are formed integrally with the housing 10 (110, 610), but the present invention is not limited to this. The protrusions 4 (14, 34) may be provided separately from the housing 10 (110, 610) and connected to each other by bolting or welding.

[0119] In the first to third embodiments, the second protrusion 41 (141) is provided so as to straddle the inclined surface portion 21 (121) and the flat portion 20 (120), but the present invention is not limited to this. The second protrusion may be provided only on the inclined surface portion 21 (121).

[0120] In the third embodiment, the heat pipe 30 is disposed in the recess 12 provided in the side surface 111 of the housing 110 (housing for a power converter), but the present invention is not limited to this. For example, the heat pipe may be disposed in the recess 2 provided in the bottom surface 11 of the housing 10 in the first embodiment.

[0121] In the fourth embodiment, the protrusion 34 has a semispherical shape, but the present invention is not limited to this. The protrusion may have a shape other than a semispherical shape (for example, a semi-ellipsoidal shape) as long as it has a curved shape without any sharp corners.

[0122] In the first to fourth embodiments, the plurality of protrusions 4 (14, 34) are arranged in a row along the sleeper direction, but the present invention is not limited to this. The plurality of protrusions 4 (14, 34) may be arranged in a zigzag (staggered) pattern along the sleeper direction.

[0123] In the fourth embodiment, the protrusion 34 having a semispherical shape is disposed in the recess 2 provided in the bottom surface 11 of the housing 10, but the present invention is not limited to this. The protrusion 34 may be disposed in the recess 12 provided in the side surface 111 of the housing 110, as in the second and third embodiments. [Explanation of symbols]

[0124] 1 Power conversion section 2 Concave part 3 Cooling fins 4, 14, 24, 34 protrusion 10, 110, 210, 310, 610 enclosure (enclosure for power conversion equipment) 11 Bottom 20, 120, 220, 320 flat part 21, 121, 221, 321 Slope section 21a, 121a surface 21b, 121b end (end of inclined surface part) 40, 140, 240 1st protrusion 41, 141, 241 2nd protrusion 40b and 140b (side 1) 40°C, 140°C (Second Side) 100, 200, 300, 400, 500, 600 power conversion devices (power conversion devices for both railway vehicles) 101a Railway car body 101b Lower Part 111 Side View Part 411 F1, F2, F3 swirling flow h1, h2 high S1 and S11 domains (domain 1) S2 and S12 domains (second domain)

Claims

1. a housing for the power conversion unit, the housing being attached to a lower portion of the railway vehicle body, housing the power conversion unit therein, and having a recessed portion recessed inward; a plurality of plate-shaped cooling fins that extend along a traveling direction of the railway vehicle body, are arranged at intervals from one another, and are disposed in the recessed portion to cool the power conversion unit by wind generated by the traveling of the railway vehicle body; a protrusion provided on the surface of the power conversion unit housing near the recessed portion, upstream of the cooling fin in the direction of travel wind, and near the end of the recessed portion in the direction of travel so as to overlap with the cooling fin when viewed from the direction of travel, the protrusion protruding in the opposite direction to the direction in which the recessed portion is recessed.

2. The power converter for a railway vehicle according to claim 1 , wherein the protrusion has a shape that generates a swirling flow downstream of the protrusion.

3. 3. The power conversion device for a railway vehicle as described in claim 2, wherein the protrusion portion has a pair of first surfaces extending so as to intersect with the surface of the power conversion unit housing near the recessed portion, and a second surface provided so as to connect the pair of first surfaces, and includes a first protrusion that extends along the running direction and has a shape that tapers downstream of the running wind.

4. The pair of first surfaces are provided so as to gradually approach each other downstream of a running wind, The power converter for a railway vehicle according to claim 3 , wherein the second surface connects the pair of first surfaces together and has a flat surface shape.

5. the recessed portion is provided on a bottom surface of the power conversion unit housing, A power conversion device for a railway vehicle as described in any one of claims 1 to 4, wherein the protrusion portion is arranged to protrude downward from the bottom surface of the power conversion unit housing near the recessed portion when the power conversion unit housing is attached to the lower part of the railway vehicle body.

6. the recessed portion is provided on a side surface of the power conversion unit housing, A power conversion device for a railway vehicle as described in any one of claims 1 to 4, wherein the protrusion portion is arranged to protrude laterally from the side surface of the power conversion unit housing near the recessed portion when the power conversion unit housing is attached to the lower part of the railway vehicle body.

7. 7. The power conversion device for a railway vehicle according to claim 1, wherein the protrusions are provided on both sides of the recessed portion in the running direction with respect to the cooling fin.

8. the recessed portion includes a flat portion provided at the center of the recessed portion in the running direction of the railway vehicle body, on which the cooling fins are arranged, and a pair of inclined surface portions arranged adjacent to both the upstream side and the downstream side of the flat portion in a running wind direction, The power converter for a railway vehicle according to claim 7 , wherein the protrusions are provided near each of the pair of inclined surface portions.

9. The power converter for a railway vehicle according to claim 8 , wherein at least a part of the protrusion is provided near an end of the inclined surface portion opposite to the flat portion.

10. 10. The power conversion device for a railway vehicle according to claim 8 or 9, wherein at least a portion of the protrusion is provided on the surface of the inclined surface portion, the protrusion extends in the running direction, and has a shape such that the height of the portion of the protrusion provided on the surface of the inclined surface portion increases downstream in the direction of running wind.

11. The power conversion device for a railway vehicle according to any one of claims 1 to 10, wherein the protrusions are arranged in a second region adjacent to the first region in which the plurality of cooling fins are provided, in a row along the direction in which the plurality of cooling fins are arranged.

12. 12. The power conversion device for a railway vehicle according to claim 11, wherein the protrusion includes a second protrusion that is provided at an end of the second region in a direction in which the plurality of protrusions are arranged, and that extends along the running direction and has a shape that tapers downstream of a running wind.

13. The power converter for a railway vehicle according to claim 2 , wherein the protrusion has a curved surface shape that is free of any sharp corners.

14. The power converter for a railway vehicle according to claim 13 , wherein the protrusion has a hemispherical shape.

15. 15. The power converter for a railway vehicle according to claim 13, wherein the protrusion having a curved surface is formed integrally with the surface of the power converter housing near the recess by press working.

16. a housing for the power conversion unit, the housing being attached to a lower portion of the railway vehicle body, housing the power conversion unit therein, and having a recessed portion recessed inward; a plurality of plate-shaped cooling fins that extend along a traveling direction of the railway vehicle body, are arranged at intervals from one another, and are disposed in the recessed portion to cool the power conversion unit by wind generated by the traveling of the railway vehicle body; a protrusion provided on a surface of the power conversion unit casing near the recessed portion and upstream of the cooling fin in the direction of a running wind, the protrusion protruding in a direction opposite to a direction in which the recessed portion is recessed, a projection having a shape that generates a swirling flow downstream of the projection in the direction of the running wind and upstream of the cooling fin in the direction of the running wind;

Images