JP2022109866A - Railroad vehicle - Google Patents

Abstract

To provide a railroad vehicle capable of facilitating inflow of travel wind into a cooling fin arranged in a concave part at a lower part of a main body of the railroad vehicle.SOLUTION: A railroad vehicle 10 includes: a main body 11 of the railroad vehicle; a power conversion part 13 mounted on the main body 11 of the railroad vehicle; a protruding concave part 15 provided on a lower part of the main body 11 of the railroad vehicle; and a plurality of plate-like cooling fins 16 arranged in the concave part 15 to cool the power conversion part 13 with travel wind of the main body 11 of the railroad vehicle. The railroad vehicle 10 further includes a protrusion part 17 provided on a surface 152a of the concave part 15 and on an upstream side of the travel wind of the cooling fins 16, and protruding downward.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to a railway vehicle, and more particularly to a railway vehicle provided with cooling fins for cooling power converters with running wind.

2. Description of the Related Art Conventionally, a railway vehicle is known that includes cooling fins that cool a power conversion unit with running wind (see, for example, Patent Literature 1).

In the railway vehicle described in Patent Document 1, a power conversion device (power conversion unit) is installed at the bottom of the vehicle. Further, the power conversion device includes a housing and a power conversion device main body provided inside the housing. Further, the power conversion device includes a cooling unit for cooling the power conversion device main body. The cooling unit has cooling fins that are exposed to the outside of the housing. In addition, the bottom of the railroad vehicle is provided with a convex concave portion on which the cooling fins are arranged.

Japanese Patent Application Laid-Open No. 2017-218000

Here, in the railway vehicle described in Patent Literature 1, the cooling fins are arranged in concave portions that are convex upward. In this case, it is thought that the flow path between the ground and the railroad vehicle is rapidly expanded by the concave portion, so that the running wind is less likely to enter the concave portion and flows to pass below the concave portion. . In this case, due to the difference in wind speed between the inner side and the outer side (ground side) of the concave portion, the central axis is formed to extend along the direction of the sleeper, causing air to stagnate (stagnate). vortex is generated in the concave portion. If a vortex is generated in the concave portion, the running wind is prevented from flowing into the cooling fins. Therefore, there is a demand for a railway vehicle that can make it easier for the running wind to flow into the cooling fins arranged in the concave portion at the bottom of the railway vehicle body.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and one object of the present invention is to make it easier to flow running wind into cooling fins arranged in a concave portion at the bottom of a railway vehicle body. It is to provide a railway vehicle that can

In order to achieve the above object, a railway vehicle according to one aspect of the present invention includes a railway vehicle body, a power converter mounted on the railway vehicle body, and an upwardly convex concave shape provided at the bottom of the railway vehicle body. a plurality of plate-like cooling fins extending along the running direction of the railroad vehicle body and arranged at intervals in the crosstie direction in the recessed portion to cool the power conversion unit by running wind of the railroad vehicle body; a projecting portion provided on the surface near the recessed portion and upstream of the cooling fins with respect to the running wind and protruding downward. Note that the vicinity of the recessed portion includes both the recessed portion itself and the portion near the recessed portion.

As described above, the railway vehicle according to one aspect of the present invention is provided with the projecting portion which is provided on the surface in the vicinity of the recessed portion and upstream of the cooling fins with respect to the running wind and protrudes downward. As a result, the direction of the running wind is changed by the projection, and the running wind can be disturbed. As a result, it is possible to reduce the swirl of the air that causes stagnation (stagnation) of the air that occurs in the recessed portion due to the turbulence of the running wind. As a result, it is possible to prevent the running wind from flowing into the cooling fins due to the vortex of air generated in the concave portion. As a result, it is possible to make it easier for the running wind to flow into the cooling fins arranged in the concave portion in the lower portion of the railway vehicle body.

In addition, it is possible to improve the cooling efficiency of the electric power conversion section by the cooling fins by facilitating the inflow of running wind into the cooling fins.

In the railway vehicle according to the above aspect, preferably the projection has a shape that generates a swirling flow downstream of the projection. With this structure, the air in the recess is agitated by the swirling flow generated in the recess, so that the vortex of the air generated in the recess can be effectively reduced. As a result, it is possible to make it easier for the running wind to flow into the cooling fins.

In this case, preferably, the protrusion has a pair of side surfaces and a lower surface, and has a shape that extends along the running direction and tapers downstream in the running wind. With such a configuration, the tapered shape of the protrusion facilitates the running wind flowing along the pair of side surfaces of the protrusion to intersect each other on the tip side of the pair of side surfaces, thereby easily generating a swirling flow. can be done.

In the railway vehicle according to the above aspect, preferably, the protrusions are provided on both sides of the recess in the running direction with respect to the cooling fins. With this configuration, the protrusion can be arranged upstream of the cooling fin regardless of the traveling direction of the railroad vehicle body.

In this case, preferably, the recessed portion includes a flat portion provided in the center where 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 running wind of the flat portion. and the protrusion is provided in the vicinity of the pair of inclined surface portions. According to this structure, the flow of running air can be disturbed by the projecting portion in the vicinity of the pair of inclined surface portions. Note that the vicinity of the inclined surface portion includes both the inclined surface portion itself and the portion near the inclined surface portion.

In the railway vehicle in which the concave portion includes a flat portion and a pair of inclined surface portions, preferably, the protrusion is provided in the vicinity of an end portion of the inclined surface portion on the side opposite to the flat portion. With this configuration, the flow of running air can be disturbed by the projecting portion near the end of the inclined surface portion. Further, since the vicinity of the end portion of the inclined surface portion is a portion where the shape of the railroad vehicle main body changes, the flow of running air tends to change. Accordingly, by arranging the protrusions at the ends where the flow of running air tends to change, the flow of running air can be changed more effectively. As a result, the flow of running wind can be disturbed more effectively. The vicinity of the end portion of the inclined surface portion includes both the end portion of the inclined surface portion itself and the portion near the end portion of the inclined surface portion.

In the railway vehicle in which the concave portion includes a flat portion and a pair of inclined surface portions, preferably, the projection portion is provided on the surface of the inclined surface portion, extends in the running direction, and extends downstream in the running direction. Therefore, it has a shape that increases in height. With this configuration, the downstream portion of the protrusion is arranged at a position close to the lower side of the concave portion, so that the flow of running air flowing below the concave portion can be easily disturbed. .

In this case, preferably, the protrusion is provided on the surface of the inclined surface portion and is provided so as to connect a pair of side surfaces that gradually approach each other toward the downstream of the running wind, and is provided so as to connect the pair of side surfaces, and a flat lower surface extending in a direction. With this configuration, the speed difference between the low-speed running wind flowing along the lower surface and the high-speed running wind flowing along the pair of side surfaces, and the speed difference between the running wind flowing along one of the pair of side surfaces and the pair of A swirling flow can be generated more easily by both the difference in angle between the running wind flowing along the other side surface and the running wind flowing along the lower surface.

In the railway vehicle in which the projection has a shape that generates a swirling flow, the projection preferably has a curved shape without sharp corners. With this configuration, stress is less likely to be concentrated on the curved surface than on a sharp corner, so local concentration of stress on the protrusion can be suppressed.

In this case, the protrusion preferably has a hemispherical shape. With this configuration, the entire protrusion has a curved shape, so that local concentration of stress on the protrusion can be further suppressed.

In the railway vehicle in which the protruding portion has a curved surface shape, preferably, the protruding portion having a curved surface shape is integrally formed with the surface in the vicinity of the concave portion by press working. With this configuration, local concentration of stress in the protrusion is suppressed, so that when the surface and the protrusion are integrally formed, the protrusion is damaged due to the stress. can be suppressed. Moreover, since the surface and the protrusion are integrally formed, it is possible to prevent the protrusion from coming off the surface. In addition, the number of parts of the railway vehicle can be reduced compared to the case where the projection is provided separately from the surface.

In the railway vehicle according to the above aspect, preferably, a plurality of protrusions are arranged side by side along the sleeper direction in a region adjacent to the region where the cooling fins are provided. According to this configuration, it is possible to suppress unevenness in the running air volume flowing into the cooling fins in the sleeper direction, compared to the case where only one protrusion is provided.

According to the present invention, as described above, it is possible to make it easier for the running wind to flow into the cooling fins arranged in the concave portion in the lower portion of the railway vehicle body.

1 is a schematic side view showing a rail vehicle according to a first embodiment; FIG. FIG. 2 is an enlarged view of the vicinity of a concave portion in FIG. 1; 1 is a perspective view of a concave portion according to a first embodiment; FIG. FIG. 4 is a partially enlarged view of the vicinity of the protrusion in FIG. 3; It is the top view which looked at the projection part by 1st Embodiment from the downward side. It is the top view which looked at the recessed part by 1st Embodiment from the downward side. FIG. 7(a) is an example of a simulation result showing the flow (streamline) of running wind in a state (comparative example) in which the protrusion is not arranged in the concave portion. FIG. 7(b) is an example of a simulation result showing the flow (streamline) of running wind in a state where the protrusion is arranged in the concave portion (first embodiment). The wind speed of the running wind at the inlet of the cooling fin in a state where the protrusion is not arranged in the concave portion (comparative example) and the speed of the cooling fin inlet in a state where the protrusion is arranged in the concave portion (first embodiment). It is an example of the simulation result which compared with the wind speed of the running wind. The wind speed of the running wind at the center of the cooling fin in a state where the protrusion is not arranged in the recessed portion (comparative example) and the speed of the running wind at the center of the cooling fin in a state where the protrusion is arranged in the recessed portion (first embodiment) It is an example of the simulation result which compared with the wind speed of the running wind. It is an enlarged view of the vicinity of the concave portion according to the second embodiment. FIG. 11 is a perspective view of a concave portion according to a second embodiment; 11 is an enlarged view of the vicinity of the protrusion in FIG. 10; FIG. It is an example of a simulation result comparing the wind speed of running wind at the entrance of the cooling fins in the comparative example, the first embodiment, and the second embodiment. It is an example of a simulation result comparing the wind speed of running wind in the center of the cooling fins in the comparative example, the first embodiment, and the second embodiment. FIG. 14 is an example of a simulation result showing variations in the wind velocity in the Y direction in each of the comparative example of FIG. 13, the first embodiment, and the second embodiment; FIG.

Embodiments embodying the present invention will be described below with reference to the drawings.

[First embodiment]
[Rail car configuration]
The configuration of a railway vehicle 10 according to the first embodiment will be described with reference to FIGS. 1 to 6. FIG.

The railway vehicle 10 is a railway vehicle that runs in a state in which a plurality of vehicles are organized. As shown in FIG. 1, the railway vehicle 10 is configured to run on electric power supplied from an overhead wire 1 as an AC power supply or a DC power supply. For example, the railcar 10 is a conventional electric train or a high-speed railcar. In the following description, a high-speed railway vehicle in which the railway vehicle 10 is an AC electric vehicle will be described as an example.

As shown in FIG. 1, the railway vehicle 10 includes a railway vehicle body 11, a pantograph 12, a power converter 13, and electrical equipment 14 such as an induction motor and an air conditioner.

The power converter 13 is mounted on the railroad vehicle main body 11 . The power conversion unit 13 is provided on the bottom portion 11 a of the railroad vehicle main body 11 .

The pantograph 12 has a role of receiving power from the overhead line 1 . The power converter 13 has a role of converting the AC voltage from the pantograph 12 transformed by a transformer (not shown) into a desired three-phase AC voltage and frequency, and outputting the same to the electrical equipment 14 and the like.

The railway vehicle 10 also includes an upwardly convex concave portion 15 provided in the lower portion of the railway vehicle body 11 . The railcar 10 also includes a plurality of plate-like cooling fins 16 arranged in the concave portion 15 . Each of the plurality of cooling fins 16 is provided so as to protrude from the lower portion of the railway vehicle 10 to the outside (atmosphere side) of the railway vehicle body 11 .

The cooling fins 16 cool the power converter 13 with the running wind of the railroad vehicle body 11 . Specifically, the cooling fins 16 are provided so as to protrude downward (Z2 side) from a cooling plate 16a (see FIG. 2) on which the power converting section 13 (semiconductor element or the like, not shown) is arranged. The plurality of cooling fins 16 extend along the running direction (X direction) of the railroad vehicle body 11 and are arranged at intervals in the crosstie direction (Y direction) (see FIG. 6).

As shown in FIG. 2, the concave portion 15 includes a flat portion 151 on which the cooling fins 16 are arranged. The flat portion 151 is provided at the center of the concave portion 15 in the X direction. Further, the concave portion 15 includes a pair of inclined surface portions 152 arranged adjacent to both the upstream side and the downstream side of the flat portion 151 with respect to the running wind.

Here, in the first embodiment, the railcar 10 includes the projecting portion 17 provided on the surface near the concave portion 15 and upstream of the cooling fins 16 with respect to the running wind and protruding downward. Specifically, the protrusion 17 is provided on a surface 152a of the concave portion 15, which will be described later. Moreover, the projecting portion 17 is formed integrally with the railroad vehicle main body 11 (bottom portion 11a). In addition, the protrusion 17 is made of metal.

Further, in the first embodiment, the protrusion 17 is provided on the inclined surface portion 152 . The surface 152 a on which the protrusion 17 is arranged is the surface provided on the inclined surface portion 152 . Moreover, the projecting portion 17 is provided so as not to form a gap with the inclined surface portion 152 .

Further, in the first embodiment, the protrusions 17 are provided on both sides of the recessed portion 15 in the running direction with respect to the cooling fins 16 . Specifically, the protrusion 17 is provided on each surface 152 a of the pair of inclined surface portions 152 . Note that the feature points such as the structure and arrangement position of the protrusions 17 provided on each of the pair of inclined surface portions 152 are the same.

Specifically, the projecting portion 17 is provided in the vicinity of the end portion 152 b of the inclined surface portion 152 opposite to the flat portion 151 . Specifically, the projecting portion 17 is arranged on the inclined surface portion 152 such that the end portion 17 a of the projecting portion 17 opposite to the flat portion 151 is provided at the end portion 152 b of the inclined surface portion 152 . Although the end portion 152b of the inclined surface portion 152 is shown to be angular in FIG. 2, the end portion 152b of the inclined surface portion 152 may have an R shape.

In addition, in the first embodiment, the protrusion 17 extends in the running direction and has a shape in which the height h increases toward the downstream side in the running direction. Specifically, the height h is 0 at the end 17a of the protrusion 17 and gradually increases toward the downstream side.

Further, as shown in FIG. 3, the protrusion 17 has a pair of side surfaces 17b and a lower surface 17c, and extends along the running direction toward the downstream of the running wind (the central side of the concave portion 15). It has a tapered shape. Specifically, the lower surface 17c has an isosceles triangular shape with the tip 17d of the projection 17 on the downstream side of the traveling wind as the apex when viewed from the bottom (as seen from the Z2 direction). Moreover, the projecting portion 17 has a right-angled triangular shape that tapers toward the upstream of the running wind when viewed from the side.

Specifically, the pair of side surfaces 17 b of the projection 17 are provided on the surface 152 a of the inclined surface portion 152 . A pair of side surfaces 17b are provided so as to cross the surface 152a. The pair of side surfaces 17b are provided so as to gradually approach each other toward the downstream side of the running wind. A lower surface 17c of the projection 17 is provided so as to connect the pair of side surfaces 17b. The lower surface 17c is a flat surface extending in the horizontal direction (a surface extending parallel to the ground).

Specifically, each of the pair of side surfaces 17b of the projecting portion 17 is provided to extend downward (Z2 direction side) from the surface 152a of the inclined surface portion 152. As shown in FIG. That is, each of the pair of side surfaces 17b is provided so as to be perpendicular to the lower surface 17c of the projection 17 extending in the horizontal direction. In the Y direction, the position where the tip 17d of the protrusion 17 is provided and the region S1 (see FIG. 3) where the cooling fins 16 are arranged are separated from each other.

In the first embodiment, as shown in FIG. 3, a plurality of projections 17 (six projections in the first embodiment) extend along the crosstie direction in a region S2 adjacent to the region S1 where the cooling fins 16 are provided. ) are arranged side by side. Specifically, in a bottom view (viewed from the Z2 direction side), the region S1 where the cooling fins 16 are provided is arranged along the X direction with the region S2 where the projections 17 are provided. . Moreover, the plurality of protrusions 17 are arranged side by side at intervals in the region S2. The same number of protrusions 17 are provided in each of the region S2 on the X1 side and the region S2 on the X2 side.

In addition, the railcar 10 is provided with a bottom portion 18 that is provided so as to be adjacent (continuous) to the recessed portion 15 in the X direction. The projecting portion 17 is provided so that the lower surface 17c does not protrude downward (Z2 direction side) with respect to the bottom surface portion 18 of the railway vehicle 10. As shown in FIG. Specifically, the lower surface 17c of the projecting portion 17 is provided so as to be flush with the bottom surface portion 18 of the railroad vehicle 10 . A lower end portion 16b (see FIG. 2) of the cooling fin 16 is provided above the bottom portion 18 of the railway vehicle 10 (Z1 direction side).

4 and 5, the protrusion 17 has a shape that generates a swirl flow F1 downstream of the protrusion 17. As shown in FIGS. Specifically, the running wind f1 flowing along one of the pair of side surfaces 17b, the running wind f2 flowing along the other of the pair of side surfaces 17b, and the running wind f3 flowing along the lower surface 17c all form the protrusion 17. cross each other on the downstream side (front end portion 17d side) of (see FIG. 5), a swirl flow F1 is formed. Note that the swirl flow F1 is a swirl flow in which the rotation axis extends along the X direction.

(simulation result)
Next, referring to FIG. 7, the case where the protrusion 17 is not provided (see FIG. 7A, comparative example) and the case where the protrusion 17 is provided (see FIG. A comparison of the air flow in the concave portion 15 with the first embodiment) will be described. In addition, in each of FIGS. 7(a) and 7(b), the flow lines of the air are indicated by dashed lines and shaded portions.

In the comparative example shown in FIG. 7( a ), the channel between the ground (not shown) and the railroad car main body 11 is suddenly enlarged by the recessed portion 15 , causing separation due to the running wind flow. is occurring. Therefore, it was confirmed that the vortex V caused by the stagnation (stagnation) of the air in the concave portion 15 was formed such that the rotation axis extended along the crosstie direction (Y direction).

In the example shown in FIG. 7B, it was confirmed that the swirling flow F1 was formed by providing the protrusion 17 in the concave portion 15 . Even in this case, while the vortex V is formed in the recessed portion 15, it is confirmed that the area where the vortex V is formed in the first embodiment is smaller than the area where the vortex V is formed in the comparative example. rice field. This is probably because the swirl flow F1 agitates the air in the concave portion 15 and reduces the stagnation of the air in the concave portion 15 .

Next, referring to FIGS. 8 and 9, comparison of the wind speed between the case where the protrusion 17 is not provided (comparative example) and the case where the protrusion 17 is provided (first embodiment). explain. Assuming that the length of the cooling fin 16 in the Z direction is H, "above" in FIGS. 8 and 9 means a position 0.75H from the end 16b (see FIG. 2) of the cooling fin 16. As shown in FIG. 8 and 9 means a position 0.5H from the end 16b of the cooling fin 16. In FIG. "Lower" in FIGS. 8 and 9 means a position 0.25H from the end 16b of the cooling fin 16. As shown in FIG. The wind speed in FIGS. 8 and 9 means the average value of the wind speed at each position in the sleeper direction.

The simulation results shown in FIG. 8 are the results at the inlet of the cooling fins 16 (position P1 in FIG. 2). As shown in FIG. 8, the wind speed of the running wind in the first embodiment is higher than the wind speed of the running wind in the comparative example for all of "upper", "middle", and "lower". rice field. Also, as can be seen from FIG. 8, it was confirmed that the effect of the first embodiment with respect to the comparative example is remarkable in the order of "upper", "middle", and "lower". In particular, it was confirmed that the wind speed of the running wind in the first embodiment was more than double the wind speed of the running wind in the comparative example at "upper" and "middle".

Also, the simulation results shown in FIG. 9 are the results at the center of the cooling fins 16 (position P2 in FIG. 2). As shown in FIG. 9, the wind speed of the running wind in the first embodiment is higher than the wind speed of the running wind in the comparative example for all of the "upper", "middle", and "lower" conditions. rice field. Also, as can be seen from FIG. 9, it was confirmed that the effect of the first embodiment relative to the comparative example is remarkable in the order of "upper", "middle", and "lower". In particular, it was confirmed that, in the case of "upper", the wind speed of the running wind in the first embodiment was about twice the wind speed of the running wind in the comparative example.

From the simulation results shown in FIGS. 7 to 9, it was confirmed that the provision of the projections 17 in the recesses 15 effectively allowed the running wind to flow into the cooling fins 16. As shown in FIG.

(Effect of the first embodiment)
The following effects can be obtained in the first embodiment.

In the first embodiment, as described above, the railway vehicle 10 is provided with the projecting portion 17 provided on the surface 152a near the recessed portion 15 and upstream of the cooling fin 16 on the upstream side of the running wind, and projecting downward. configure. As a result, the projection 17 changes the direction of the flow of the running wind, thereby making it possible to cause turbulence in the flow of the running wind. As a result, it is possible to reduce the air vortex V that causes stagnation (stagnation) of the air generated in the concave portion 15 due to the turbulence of the running wind. As a result, it is possible to prevent the air vortex V generated in the concave portion 15 from hindering the running wind from flowing into the cooling fins 16 . As a result, it is possible to make it easier for the running wind to flow into the cooling fins 16 arranged in the concave portion 15 in the lower portion of the railroad vehicle main body 11 .

In addition, the cooling efficiency of the cooling fins 16 can be improved by facilitating the inflow of running wind into the cooling fins 16 .

Further, in the first embodiment, as described above, the railcar 10 is configured such that the protrusion 17 has a shape that generates the swirl flow F1 downstream of the protrusion 17 . As a result, the air in the recessed portion 15 is stirred by the swirling flow F1 by generating the swirling flow F1 in the recessed portion 15, so that the vortex V of the air generated in the recessed portion 15 can be effectively reduced. . As a result, it is possible to make it easier for the running wind to flow into the cooling fins 16 .

Further, in the first embodiment, as described above, the protrusion 17 has a pair of side surfaces 17b and a lower surface 17c, and has a shape that extends along the running direction and tapers toward the downstream side of the running wind. The railcar 10 is configured to have. As a result, the tapered shape of the protrusion 17 makes it easier for the running wind flowing along the pair of side surfaces 17b of the protrusion 17 to cross each other on the tip side of the pair of side surfaces 17b, thereby easily generating the swirling flow F1. be able to.

Further, in the first embodiment, as described above, the railcar 10 is configured such that the protrusions 17 are provided on both sides of the recesses 15 in the running direction with respect to the cooling fins 16 . As a result, the projecting portion 17 can be arranged on the upstream side of the cooling fins 16 regardless of the traveling direction of the railroad car body 11 .

Further, in the first embodiment, as described above, the railcar 10 is configured such that the protrusions 17 are provided in the vicinity of the pair of inclined surface portions 152 . As a result, the protrusion 17 can disturb the flow of the traveling air in the vicinity of the pair of inclined surface portions 152 .

Further, in the first embodiment, as described above, the railcar 10 is configured such that the projecting portion 17 is provided in the vicinity of the end portion 152b of the inclined surface portion 152 opposite to the flat portion 151 . As a result, in the vicinity of the end portion 152b of the inclined surface portion 152, the projection portion 17 can disturb the flow of the running air. Further, since the vicinity of the end portion 152b of the inclined surface portion 152 is a portion where the shape of the railroad vehicle main body 11 changes, the flow of running air tends to change. Accordingly, by arranging the protrusion 17 at the end portion 152b where the flow of the running wind tends to change, the flow of the running wind can be changed more effectively. As a result, the flow of running wind can be disturbed more effectively.

Further, in the first embodiment, as described above, the protrusion 17 is provided on the surface 152a of the inclined surface portion 152, extends in the running direction, and increases in height h as it goes downstream in the running direction. The railcar 10 is constructed so as to have a shape in which . As a result, the downstream portion of the protrusion 17 is arranged at a position close to the lower side of the concave portion 15, so that the flow of running air flowing below the concave portion 15 can be easily disturbed.

Further, in the first embodiment, as described above, the protrusion 17 is provided on the surface 152a of the inclined surface portion 152 and forms a pair of side surfaces 17b that gradually approach each other downstream of the running wind. and a flat lower surface 17c provided to connect and extending in a direction along the horizontal direction. As a result, the speed difference between the low-velocity running wind f3 flowing along the lower surface 17c and the high-velocity running wind (f1, f2) flowing along the pair of side surfaces 17b, and The swirling flow F1 can be more easily generated by both the traveling wind f1 flowing along the other of the pair of side surfaces 17b and the angular difference between the traveling wind f3 flowing along the lower surface 17c.

Further, in the first embodiment, as described above, in the area S2 adjacent to the area S1 in which the cooling fins 16 are provided, the protrusions 17 are arranged side by side along the sleeper direction. A vehicle 10 is configured. As a result, compared to the case where only one protrusion 17 is provided, it is possible to suppress the unevenness in the running air volume flowing into the cooling fins 16 in the sleeper direction.

[Second embodiment]
A second embodiment will be described with reference to FIGS. 10 to 15. FIG. In this second embodiment, unlike the first embodiment in which the protrusion 17 including a pair of side surfaces 17b and a lower surface 17c is provided, a protrusion 117 having a curved shape is provided. In the figure, the same reference numerals are given to the same configurations as those of the first embodiment, and the description thereof will be omitted.

[Rail car configuration]
The configuration of the railcar 110 according to the second embodiment will be described with reference to FIGS. 10 to 12. FIG.

As shown in FIG. 10 , the railcar 110 includes a railcar body 111 . The railcar 110 also includes a protrusion 117 . The projecting portion 117 is provided on the railway vehicle main body 111 . Specifically, the projecting portion 117 is arranged on the inclined surface portion 152 of the railway vehicle body 111 . An end portion 117 a of the projection portion 117 opposite to the flat portion 151 is provided at an end portion 152 b of the inclined surface portion 152 .

Here, in the second embodiment, as shown in FIG. 11, the protrusion 117 has a curved shape without sharp corners. Specifically, the surface of the protrusion 117 is curved as a whole without including a flat portion or a corner portion.

Specifically, protrusion 117 includes a hemispherical shape. The term "hemispherical shape" does not mean only a shape obtained by cutting 1/2 of a sphere, but has a broader meaning including shapes obtained by cutting other than 1/2 of a sphere (for example, 2/3 of a sphere). .

Moreover, the protrusion 117 has a shape that generates a swirl flow F2 downstream of the protrusion 117 . Specifically, the traveling winds f11 flowing along the surface of the protrusion 117 cross each other on the downstream side of the protrusion 117, thereby forming the swirling flow F2. Note that the swirl flow F2 is a swirl flow in which the rotation axis extends along the X direction.

Further, in the second embodiment, the protrusion 117 having a curved surface shape is integrally formed with the surface 152a of the inclined surface portion 152 by press working. Specifically, as shown in FIG. 12, the protrusion 117 includes an outer peripheral edge 117b formed during press working of the protrusion 117 . The outer peripheral edge 117b has an R shape.

A lower end 117c of the projecting portion 117 is provided below the bottom portion 18 (Z2 side). In other words, the protrusion 117 is provided so as to protrude from the concave portion 15 . A lower end 117c of the projecting portion 117 is provided on the upper side (Z1 side) of the outfitting limit L of the railway vehicle body 11 (see FIG. 10).

(simulation result)
Next, FIGS. 13 to 15 show the case where no protrusion is provided (comparative example), the case where the protrusion 17 is provided (first embodiment), and the case where the protrusion 117 is provided. (2nd Embodiment) and the simulation result about the comparison of the wind speed are shown.

From the wind speed (see FIG. 13) at the inlet (position P1 in FIG. 10) of the cooling fin 16 and the wind speed (see FIG. 14) at the center (position P2 in FIG. 10) of the cooling fin 16, the projection 117 in the second embodiment It was confirmed that the effect is substantially the same as the effect of the protrusion 17 in the first embodiment.

FIG. 15 also shows variations in wind speed at position P1. A solid line, a dashed line, and a dashed line indicate the results of the second embodiment, the first embodiment, and the comparative example, respectively. As shown in FIG. 15, it was confirmed that the second embodiment has smaller variations in wind speed in the Y direction than the first embodiment. Although not shown, similar results were obtained at the position P2.

Other configurations of the second embodiment are the same as those of the first embodiment.

(Effect of Second Embodiment)
The following effects can be obtained in the second embodiment.

In the second embodiment, as described above, the railcar 110 is configured such that the protrusion 117 has a curved shape without sharp corners. As a result, stress is less likely to be concentrated on the curved surface than on a sharp corner, so local concentration of stress on the protrusion 117 can be suppressed.

In the second embodiment, as described above, the railcar 110 is configured such that the protrusion 117 has a hemispherical shape. As a result, the projection 117 as a whole has a curved shape, so that local concentration of stress on the projection 117 can be further suppressed.

In the second embodiment, as described above, the railway vehicle 110 is configured such that the projection 117 having a curved surface shape is integrally formed with the surface 152a near the concave portion 15 by press working. As a result, the local concentration of stress in the protrusion 117 is suppressed, so that the protrusion 117 is damaged due to the stress when the surface 152a and the protrusion 117 are integrally formed. can be suppressed. Moreover, since the surface 152a and the protrusion 117 are integrally formed, it is possible to prevent the protrusion 117 from coming off the surface 152a. In addition, the number of parts of railcar 110 can be reduced compared to the case where projecting portion 117 is provided separately from surface 152a.

Other effects of the second embodiment are the same as those of the first embodiment.

(Modification)
It should be noted that the embodiments disclosed this time should be considered as examples and not restrictive in all respects. The scope of the present invention is indicated by the scope of the claims rather than the description of the above-described embodiments, and includes all modifications (modifications) within the scope and meaning equivalent to the scope of the claims.

For example, in the above-described first and second embodiments, the projecting portion 17 (117) is provided in the recessed portion 15, but the present invention is not limited to this. For example, the protrusion 17 (117) may be provided in the vicinity of the end 152b of the concave portion 15 (inclined surface portion 152) and on the bottom surface portion 18 of the railway vehicle body 11 (111). Moreover, the protrusion 17 (117) may be arranged so as to straddle the bottom surface 18 and the concave portion 15 .

Further, in the above-described first and second embodiments, an example in which the protrusion 17 (117) has a shape that generates the swirl flow F1 (F2) is shown, but the present invention is not limited to this. The projecting portion 17 (117) may not have a shape that generates the swirl flow F1 (F2) as long as it has a shape that disturbs the running wind flow.

Further, in the first embodiment described above, an example is shown in which the shape extends along the running direction and tapers downstream of the running wind, but the present invention is not limited to this. For example, a pair of side surfaces of the protrusion may have a curved shape.

Further, in the first embodiment, the lower surface 17c is a flat surface extending in the horizontal direction (a surface extending parallel to the ground), but the present invention is not limited to this. For example, the lower surface 17c may be a surface that extends upward with respect to the ground.

Further, in the first embodiment, the lower surface 17c has an isosceles triangular shape when viewed from the bottom (as seen from the Z2 direction), with the tip 17d of the projection 17 on the downstream side of the running wind as the apex. Although an example is shown, the present invention is not limited to this. For example, the lower surface 17c may have a triangular shape other than an isosceles triangle, or may have a trapezoidal shape without the tip portion 17d.

Further, in the first embodiment, each of the pair of side surfaces 17b is provided so as to be perpendicular to the lower surface 17c of the projection 17 extending in the horizontal direction, but the present invention is not limited to this. For example, the angle formed by each of the pair of side surfaces 17b and the lower surface 17c of the horizontally extending protrusion 17 may be an acute angle or an obtuse angle.

Further, in the first and second embodiments, an example was shown in which the protrusion 17 (117) is provided so as not to form a gap with the inclined surface portion 152, but the present invention is not limited to this. The railway vehicle may be provided with a protrusion that is provided so as to form a gap with respect to the inclined surface portion 152 .

Further, in the above-described first and second embodiments, an example in which the protrusions 17 (117) are provided on both sides of the cooling fins 16 in the traveling direction has been described, but the present invention is not limited to this. The protrusion 17 (117) may be provided on one side of the cooling fin 16 in the running direction.

Further, in the first and second embodiments, an example in which the projections 17 (117) are provided in the vicinity of the end portions 152b of the pair of inclined surface portions 152 is shown, but the present invention is not limited to this. For example, protrusion 17 (117) may be provided to extend from end 152b to the vicinity of cooling fin 16. FIG.

Further, in the above-described embodiment, an example is shown in which the protrusion 17 has a shape in which the height h increases as it goes downstream in the running direction, but the present invention is not limited to this. For example, the height of the protrusion may decrease as it goes downstream, or may be the same size at any position in the running direction.

Further, in the above-described first and second embodiments, in the region S2 adjacent to the region S1 where the cooling fins 16 are provided, a plurality of projections 17 (117) are arranged side by side along the crosstie direction. Although shown, the invention is not so limited. Only one protrusion 17 (117) may be arranged in the region S2.

Further, in the above-described first and second embodiments, an example in which the railroad vehicle 10 is an electric train on a conventional line or a high-speed railroad vehicle has been described, but the present invention is not limited to this. For example, the railcar may be a diesel car (a train with an engine).

Further, in the above-described first and second embodiments, an example in which the concave portion 15 is provided with the pair of inclined surface portions 152 is shown, but the present invention is not limited to this. The concave portion may not be provided with the inclined surface portion.

Further, in the second embodiment, an example in which the projection 117 has a hemispherical shape is shown, but the present invention is not limited to this. The protrusion may have a shape other than a hemispherical shape (for example, a semi-ellipsoidal shape) as long as it has a curved shape without sharp corners.

Further, in the first and second embodiments, an example in which a plurality of protrusions 17 (117) are arranged in a line along the crosstie direction was shown, but the present invention is not limited to this. A plurality of protrusions 17 (117) may be arranged in a zigzag (staggered) pattern along the sleeper direction.

Further, in the first and second embodiments, an example in which the protrusion 17 (117) is formed integrally with the railway vehicle main body 11 (111) (inclined surface portion 152) was shown, but the present invention is not limited to this. Not limited. The projecting portion 17 (117) may be formed separately from the railway vehicle main body 11 (111). That is, the projecting portion 17 (117) may be fastened to the railway vehicle main body 11 (111) (inclined surface portion 152) by a fastening member or the like.

REFERENCE SIGNS LIST 10, 110 railcar 11, 111 railcar main body 13 power converter 15 concave portion 16 cooling fin 17, 117 protrusion 17b side surface 17c lower surface 151 flat portion 152 inclined surface portion 152a surface (surface of concave portion, surface of inclined surface portion)
152b end F1, F2 swirling flow h height S1 region (region provided with cooling fins)
S2 area (area where the protrusion is arranged)

Claims (12)

a railway vehicle body;
a power conversion unit mounted on the railway vehicle body;
an upwardly convex concave portion provided in the lower portion of the railway vehicle body;
a plurality of plate-shaped cooling fins extending along the running direction of the railroad vehicle main body and arranged at intervals in the crosstie direction in the recessed portion for cooling the power conversion unit by running wind of the railroad vehicle main body; ,
a projecting portion provided on a surface in the vicinity of the recessed portion and on an upstream side of the cooling fins with respect to the running wind, and protruding downward. 2. The railway vehicle according to claim 1, wherein said projection has a shape that generates a swirling flow downstream of said projection. 3. The railway vehicle according to claim 2, wherein said projecting portion has a pair of side surfaces and a lower surface, and has a shape that extends along said running direction and tapers downstream in the running wind. The railway vehicle according to any one of claims 1 to 3, wherein the protrusions are provided on both sides of the concave portion in the running direction with respect to the cooling fins. The recessed portion is provided in the center and includes a flat portion on which the cooling fins are arranged, and a pair of inclined surface portions arranged adjacent to both upstream and downstream sides of the running wind of the flat portion,
5. The railway vehicle according to claim 4, wherein said projecting portion is provided in the vicinity of said pair of inclined surface portions. 6. The railway vehicle according to claim 5, wherein said projecting portion is provided in the vicinity of an end portion of said inclined surface portion opposite to said flat portion. 6. The protrusion is provided on the surface of the inclined surface portion, and has a shape extending in the running direction and increasing in height as it goes downstream in the running direction. Or the rail vehicle according to 6. The projecting portion is provided on the surface of the inclined surface portion and is provided so as to connect a pair of side surfaces that gradually approach each other toward the downstream side of the traveling wind, and the pair of side surfaces, and extends in a horizontal direction. 8. The railcar of claim 7, comprising a flat lower surface. 3. The railway vehicle according to claim 2, wherein said projecting portion has a curved shape without sharp corners. The railway vehicle according to claim 9, wherein the protrusion has a hemispherical shape. 11. The railway vehicle according to claim 9, wherein said protrusion having a curved surface shape is integrally formed with said surface near said concave portion by press working. The railway vehicle according to any one of claims 1 to 11, wherein a plurality of said protrusions are arranged side by side along said sleeper direction in a region adjacent to said region where said cooling fins are provided.

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