JP2024080245A - Railway vehicles and train sets - Google Patents

Abstract

[Problem] To provide a railway vehicle and train set equipped with bogies that can reduce air resistance without having bogie covers or the like that cover and conceal the bogie frame, which is likely to be an indirect cause of hindering maintainability. [Solution] In a railway vehicle having a railway car body and a pair of bogies that support the railway car body, at least one of the bogies is equipped with a resistance reduction member fixed to a center beam, and the resistance reduction member has a surface that faces the width direction of the railway car, extending from one wheel side to the other wheel side along the longitudinal direction of the railway car. As a result, air resistance can be reduced without having a bogie cover that covers and conceals the bogie frame, which is likely to be an indirect cause of hindering maintainability, or a cover that is placed approximately in the same place as the cover that covers the underfloor equipment of the railway car and is provided on the side of the car body. [Selected Figure] Figure 3

Description

The present invention relates to railway vehicles and train formations.

In general, resistance in railway vehicles can be broadly divided into mechanical resistance such as resistance between the bearings and the wheelsets and between the wheels and the rails, and air resistance caused by turbulence in the air around the railway vehicle. Mechanical resistance increases in proportion to the first power of the railway vehicle's speed (i.e., speed), whereas air resistance increases in proportion to the square of the railway vehicle's speed. For this reason, in order to reduce the resistance of railway vehicles traveling at high speeds and thereby reduce power consumption, it is desirable to reduce air resistance as much as possible.

Patent document 1 discloses a railway vehicle in which the bogie is covered with a side cover to reduce the air resistance generated by the bogie and its cavity when traveling at high speeds.

The side cover disclosed in Patent Document 1 differs from conventional bogie side covers in that it is attached to the bogie and can rotate together with the bogie around an axis approximately vertical to the car body. Therefore, even if the gap with the bogie is narrowed so as not to exceed the vehicle limit, the side cover does not interfere with the bogie, and further has the characteristic that it has no contact points with the railway vehicle body and no contact points with the railway vehicle undercarriage except for the bogie itself.

Furthermore, this side cover is a multi-part bogie side cover, i.e., it is made up of multiple cover parts. A side cover made up of multiple cover parts has the characteristic of having cusps located on the front and rear edges to allow relative movement and deformation of the bogie frame, and to allow smooth airflow around the side of the railcar on the side of the cover and inside the cavity under the railcar body that houses the bogie, with minimal interference with the bogie itself.

Patent No. 6473257

However, railway vehicle bogies require various inspection procedures, such as visually checking the level of the lubricating oil in the bearings and the wear condition of the brake shoes of the braking device, and tapping the bolts that secure the main motor to the bogie frame with an inspection hammer to make sure they are not loose. In contrast, the side cover disclosed in Patent Document 1 is made up of many cover parts, so in order to inspect the bogie, the many bolts that attach the cover parts to the bogie must be removed and each cover part must be disassembled, which is time-consuming. Therefore, in order to reduce the labor required for inspection work, it is desirable to eliminate windshield covers that cover the bogie from the outside as much as possible.

The present invention aims to provide a railway vehicle and a train set equipped with bogies that can reduce air resistance without using bogie covers that conceal the bogie frame, which can be an indirect cause of hindering maintainability.

In order to achieve the above object, one representative railway vehicle of the present invention comprises:
A railway vehicle having a railway car body and a pair of bogies supporting the railway car body,
The cart is
A pair of side beams provided along a longitudinal direction of the railcar and spaced apart in a width direction of the railcar;
A center sill that connects center portions of the side sills in a longitudinal direction of the railway vehicle;
A wheel set consisting of a pair of wheels and an axle;
an axle box that rotatably holds both ends of the wheel set and is supported on the side beam via an axle box support device;
At least one of the bogies includes a resistance reducing member fixed to the center beam,
This is achieved by the resistance reduction member having a surface that extends from one wheel side to the other wheel side along the longitudinal direction of the railway vehicle and faces in the width direction of the railway vehicle.

According to the present invention, it is possible to provide a railway vehicle and a train formation equipped with bogies that can reduce air resistance without having to use bogie covers or the like that cover and conceal the bogie frame, which is likely to be an indirect cause of impeding maintainability.
Problems, configurations and effects other than those described above will become apparent from the following description of the embodiments.

FIG. 1 is a perspective view showing a conventional configuration of the bogie and its surroundings of a railway vehicle. FIG. 2 is a schematic diagram for explaining the air flow around the bogie of the railway vehicle. FIG. 3 is a perspective view of the railway vehicle according to the first embodiment as viewed from below. FIG. 4 is a bottom view of the railway vehicle according to the first embodiment. FIG. 5 is a perspective view of the railway vehicle according to the second embodiment as viewed from below. FIG. 6 is a side view of a railway vehicle according to the second embodiment. FIG. 7 is a perspective view of a railway vehicle according to the third embodiment as viewed from below. FIG. 8 is a side view and a partially enlarged view of an entire train made up of railway cars according to the fourth embodiment.

Below, an embodiment of a railway vehicle according to the present invention will be described with reference to the drawings. First, in order to explain the configuration of the railway vehicle, each direction will be defined. The longitudinal direction of the railway vehicle is the x-direction, the width direction of the railway vehicle is the y-direction, and the height direction of the railway vehicle is the z-direction. Below, these directions may be simply referred to as the x-direction, y-direction, and z-direction.

Figure 1 is a perspective view showing a conventional configuration of the bogie and its surroundings for a railway vehicle. A railway vehicle is composed of a railway car body 1 having a passenger compartment space for passengers and the like, and a pair of bogies 20 (only one is shown) that support the lower ends of both ends of the railway car body 1 in the x direction. The bogie 20 is composed of a pair of side beams 22 arranged along the x direction and spaced apart in the y direction, a center beam 24 that connects the central parts of the side beams 22 in the x direction, a wheel set consisting of a pair of wheels 26a, 26b and axles 27a, 27b that connect both wheels, and an axle box that rotatably holds both ends of the wheel set and is supported by the side beams 22 via an axle box support device.

The railway car body 1 is elastically supported by air springs 28 provided at the upper center of the side beams 22 of the bogie 20 in the x-direction.

The bogie 20 is installed in a bogie cavity portion 14 provided at the bottom of the railway car body 1 so that it can rotate freely in a substantially horizontal plane relative to the railway car body 1. The bogie cavity portion 14 refers to a recessed space whose upper surface is surrounded by the underside of the underframe 10 that constitutes the floor of the railway car body 1 and end blocking plates 12a, 12b provided on the front and rear (x-direction) end surfaces of the underframe 10. Both sides of the bogie cavity portion 14 in the y direction are side opening portions that are open to the outside.

Next, the flow of air that flows into the bogie cavity from the side while the vehicle is running will be explained using Figure 2. Figure 2 is a schematic diagram for explaining the air flow around the bogie of a railway vehicle.

When a railway vehicle travels in the direction of arrow 90 in Figure 2, the airflow W along the side wall of the railway vehicle body 1 flows from the side opening toward the center of the bogie cavity portion 14 in the y direction, and after colliding with the rear wheel 26b, it branches into an airflow Wa toward the outside of the wheel 26b and an airflow Wb toward the center of the wheel 26b (the center side of the longitudinal direction of the axle 27b). At this time, fluid resistance is generated at the wheel 26b. In addition, the branched airflow Wb is a fast flow with a flow velocity similar to that of the airflow W along the side wall, and when this airflow collides with the axle 27b or the end blocking plate 12b, it leads to the generation of large fluid resistance.

From the above phenomenon, it is presumed that fluid resistance can be reduced if the airflow W from the side opening can be prevented from flowing into the bogie cavity 14. If the side opening of the bogie cavity 14 is covered with a cover extending from the railway car body 1, the airflow W can be prevented from flowing into the bogie cavity 14, but this will cause interference between the bogie 20 and the cover when the bogie 20 rotates. According to the structure of the railway car in the embodiment described below, a thin plate-shaped resistance reducing member (deflector) 50 is installed between the wheels 26a and 26b, so that the flow entering the bogie cavity 14 can be prevented without causing interference with the bogie 20. A specific embodiment will be described below.

First Embodiment
FIG. 3 is a perspective view of the railway vehicle according to the first embodiment as viewed from the bottom, and FIG. 4 is a bottom view of the railway vehicle according to the first embodiment as viewed from the bottom. FIG. 3 shows a pair of resistance reduction members (deflectors) 50 installed below in the z direction between the wheels 26a and 26b. Each resistance reduction member (deflector) 50 is composed of a pair of rectangular column-shaped connection parts 50a connected to the center beam 24 and spaced apart along the x direction, and a rectangular column-shaped horizontal part 50b extending in the x direction. The connection parts 50a are connected to a location other than both ends of the horizontal part 50b, for example, connected to a position spaced apart from the end of the horizontal part 50b by 1/3 of the total length of the horizontal part 50b. The resistance reduction member 50 extends from one wheel 26a side toward the other wheel 26b side in the vehicle travel direction, and its thickness in the y direction is set to be equal to or less than the thickness dimension of the wheel so that it does not become a source of air resistance itself. Also, with respect to the height dimension in the z direction, a limit (a dimensional limit in the z direction) is set so that the lower end of the horizontal portion 50b constituting the resistance reducing member 50 does not come into contact with the top of the rail.

In this embodiment, when the resistance reduction member 50 is projected in the y direction, the y-direction projection image does not overlap the wheels 26a and 26b, and when the resistance reduction member 50 is projected in the z direction, the z-direction projection image does not overlap the wheels 26a and 26b. In addition, it is preferable that the position of the surface facing outward in the y direction of each resistance reduction member 50 extending from the wheel 26a side to the wheel 26b side along the longitudinal direction of the railway vehicle approximately coincides with the position of the outer side surface of the wheels 26a and 26b. The lower surface of the horizontal portion 50b is located above the tread surfaces of the wheels 26a and 26b in the z direction.

With reference to FIG. 4, the air flow around the bogie cavity portion 14 is shown, and its effect is described. When the railroad vehicle travels in the direction of the arrow 90 in FIG. 4, the air flow W flowing along the side wall of the car body flows from the side opening in the y direction of the bogie cavity portion 14 toward the center in the y direction (i.e., the y-direction component of the air flow increases). However, when the air flow hits the surface facing outward in the y direction of the resistance reduction member (deflector) 50 (particularly the horizontal portion 50b), the flow direction is deflected to a flow along the x direction (meaning that the y-direction component of the air flow is reduced and the x-direction component is increased compared to immediately before hitting the resistance reduction member 50), and then the air flow passes outside the bogie cavity portion 14. This prevents the air flow W from colliding with the axle 27b or the end blocking plate 12b, and reduces the fluid resistance of the railroad vehicle. In addition, if the direction of travel is always one-way, such as in the case of a railway vehicle traveling on a loop line, the resistance reduction member 50 may be provided only on the bogie at the front of the direction of travel, and not on the bogie at the rear.

Furthermore, according to this embodiment, when the resistance reducing member 50 is attached, the wheels 26a and 26b are exposed to the side, so the resistance reducing member 50 does not get in the way during maintenance and inspection of these wheels. Also, compared to the case where the bogie is covered with a windshield cover made up of many parts, it is possible to significantly reduce the number of parts.

Second Embodiment
Fig. 5 is a perspective view seen from below of a railway vehicle according to the second embodiment, and Fig. 6 is a side view of the railway vehicle according to the second embodiment. In the second embodiment, a description of the configuration common to the first embodiment will be omitted, and the configuration unique to the second embodiment will be mainly described.

The second embodiment is characterized in that the resistance reduction member (deflector) 50 extends in the x direction up to the vicinity of the treads (surfaces that abut the rails) of the wheels 26a and 26b. Therefore, when the horizontal portion 50b is projected in the z direction, the z-direction projection image overlaps the wheels 26a and 26b. However, in order to avoid interference between the wheels 26a and 26b and to form a gap, the horizontal portion 50b faces and is spaced from the treads of the wheels 26a and 26b, respectively, and has slopes 50c at its ends that are inclined with respect to the x direction.

According to the second embodiment, by reducing the gap between both ends of the horizontal portion 50b of the resistance reduction member (deflector) 50 in the x direction and the treads of the wheels 26a and 26b, the airflow W along the side of the railway car body 1 can be prevented from flowing near the tread of the wheel 26a, thereby suppressing the generation of fluid resistance caused by the airflow W colliding with the wheel 26.

Third Embodiment
7 is a perspective view of a railway vehicle according to the third embodiment as seen from below. Descriptions of parts common to the above-mentioned embodiments will be omitted, and the description will focus on configurations unique to the third embodiment. In the first and second embodiments, the connection parts 50a of the resistance reduction member (deflector) 50 are spaced apart in the x direction, and a space is provided between the front connection part 50a and the rear connection part 50a.

In contrast, the resistance reducing member (deflector) 50 of the third embodiment is characterized in that it has a planar shape along the x direction, eliminating the gaps that existed between the connecting parts 50a of the above-mentioned embodiment. Specifically, the resistance reducing member 50 has a shape in which a single connecting part 50a in the shape of a square tube extending in the x direction is superimposed on a horizontal part 50b in the shape of a square tube extending in the x direction, and the outer surfaces in the y direction of the connecting part 50a and the horizontal part 50b are flush with each other. In this case, it is preferable that the yz-direction cross section of the connecting part 50a is equal to the yz-direction cross section of the horizontal part 50b, and the x-direction length (first length) of the connecting part 50a is shorter than the x-direction length (second length) of the horizontal part 50b, for example, 1/3.

The configuration of this embodiment can prevent the airflow W along the side of the railway car body 1 from flowing between the center beam 24 and the horizontal portion 50b, thereby suppressing the generation of fluid resistance caused by the airflow W colliding with the wheels 26. The resistance reducing member 50 can also be trapezoidal when viewed in the y direction. In this case, the upper portion of the resistance reducing member 50 including the upper edge can be the connection portion 50a, and the lower portion including the lower edge can be the horizontal portion 50b.

Fourth Embodiment
8 is a side view of the entire train made up of railway vehicles according to the fourth embodiment. The entire train is made up of cars 30a, 30b, 30c, 30d, and 30e, which are coupled via coupling parts in the following order. Each car includes a railway car body 1 having a passenger compartment for passengers and the like, and a pair of bogies 20 supporting the lower portions of both ends of the railway car body 1 in the x direction (see FIG. 3).

It is possible to provide resistance reduction members 50 on all of the bogies of each of the individual railway cars that make up such a train, but this would result in an increase in the weight of the car and in costs. On the other hand, the air flow W along the side of the railway car body 1 is affected by shear friction forces and its flow speed decreases from the leading car in the direction of travel (one of the railway cars at either end of the train) to the cars further back, so the effect of the aforementioned resistance reduction members (deflectors) 50 in suppressing the generation of fluid resistance also decreases.

Therefore, in the fourth embodiment, the resistance reduction member (deflector) 50 is placed on the bogie in front of the leading car 30a in the traveling direction, where the influence of the shear friction force in the airflow is the smallest. Furthermore, assuming that the train cars travel in the opposite direction, the resistance reduction member (deflector) 50 is also placed on the bogie in the rear of the trailing car 30e in the traveling direction. In other words, the resistance reduction member 50 is placed on the bogie closest to the uncoupled part in the railway cars (generally cars with a driver's cab) at both ends of the train cars. The resistance reduction member 50 is not provided on the cars 30b, 30c, and 30d that do not have an uncoupled part. In this way, by arranging the resistance reduction member 50 only on the bogie that can maximize the air resistance reduction effect, it is possible to achieve a high level of both the air resistance reduction effect, the reduction in total weight, and the improvement in manufacturability while ensuring the bidirectional mobility of the train cars. It is also possible to provide the resistance reduction member 50 on all the bogies of the leading car 30a and the trailing car 30e.

The airflow control resistance reduction member (deflector) 50 used in the above-described embodiment is made of a lightweight material such as fiber reinforced plastic (FRP) or carbon fiber reinforced plastic (CFRP). By making the resistance reduction member (deflector) 50 from a lightweight reinforced plastic, the total weight of the railway vehicle due to its installation can be reduced, and reduction in strength due to fatigue, etc. can be mitigated.

By using a railway vehicle with the above configuration, it is possible to provide a railway vehicle equipped with a bogie that can reduce air resistance without the need for a bogie cover that conceals the bogie frame, which can be an indirect cause of hindering maintainability, or a cover that is placed approximately in the same place as the cover that covers the underfloor equipment of the railway vehicle and is installed on the side of the car body.

This specification includes the disclosure of the following inventions.
(First aspect)
A railway vehicle having a railway car body and a pair of bogies supporting the railway car body,
The cart is
A pair of side beams provided along a longitudinal direction of the railcar and spaced apart in a width direction of the railcar;
A center sill that connects center portions of the side sills in a longitudinal direction of the railway vehicle;
A wheel set consisting of a pair of wheels and an axle;
an axle box that rotatably holds both ends of the wheel set and is supported on the side beam via an axle box support device;
At least one of the bogies includes a resistance reducing member fixed to the center beam,
A railway vehicle, characterized in that the resistance reduction member extends from one wheel side to the other wheel side along the longitudinal direction of the railway vehicle and has a surface facing in the width direction of the railway vehicle.

(Second embodiment)
In the railway vehicle of the first aspect,
The resistance reducing member is
a connection portion connected to the center beam and spaced apart in a longitudinal direction of the railcar;
a horizontal portion connected to a lower end of the connection portion and provided along the longitudinal direction of the railway vehicle.

(Third Form)
In the railway vehicle of the second aspect,
a thickness of the horizontal portion in a width direction of the railway vehicle is equal to or smaller than a thickness dimension of the wheel,
A railway vehicle, characterized in that a lower end of the horizontal portion does not contact a top of the rail.

(Fourth Form)
In the railway vehicle of the second or third aspect,
a horizontal portion having a width extending from the wheel tread to the vicinity of the wheel tread, the horizontal portion having a slope that faces the wheel tread and is spaced from the wheel tread and inclined with respect to the longitudinal direction of the railway vehicle;

(Fifth Form)
In the railway vehicle of the first aspect,
The resistance reducing member is
a connection portion extending a first length along a longitudinal direction of the railcar and connected to the center beam;
a horizontal portion extending along a longitudinal direction of the railcar by a second length longer than the first length; and
The railway vehicle, wherein the outer surfaces of the connection portion and the horizontal portion in the width direction of the railway vehicle are flush with each other.

(Sixth Form)
A train made up of a plurality of railway cars, the at least one of which is a railway car according to any one of the first to fifth embodiments.

(Seventh Form)
In the sixth embodiment of the train,
The rail cars at both ends of the train are
a bogie provided with the resistance reducing member at both ends of the train;
and a bogie located at a center side of the train body and not including the resistance reduction member.

(Eighth embodiment)
In the sixth or seventh embodiment of the train,
A train of vehicles, characterized in that the railway cars other than those at both ends of the train of vehicles have only bogies that are not equipped with the resistance reduction member.

1... railway car body, 10... frame,
12a, 12b... end closing plate, 14... bogie cavity portion,
20... bogie, 22... side beam,
24... center beam, 26a, 26b... wheels,
27a, 27b... axles; 28... air spring;
30a, 30b, 30c, 30d, 30e...vehicles (railroad vehicles),
50: resistance reducing member (deflector); 50a: connection portion;
50b... horizontal portion; 90... arrow indicating the direction of travel of the railway vehicle;
x...rail (longitudinal) direction, y...sleeper (width) direction,
z: height direction; W: airflow from the side;
Wa, Wb: Air flows branching from air flow W

Claims (8)

A railway vehicle having a railway car body and a pair of bogies supporting the railway car body,
The cart is
A pair of side beams provided along a longitudinal direction of the railcar and spaced apart in a width direction of the railcar;
A center sill that connects center portions of the side sills in a longitudinal direction of the railway vehicle;
A wheel set consisting of a pair of wheels and an axle;
an axle box that rotatably holds both ends of the wheel set and is supported on the side beam via an axle box support device;
At least one of the bogies includes a resistance reducing member fixed to the center beam,
A railway vehicle, characterized in that the resistance reduction member extends from one wheel side to the other wheel side along the longitudinal direction of the railway vehicle and has a surface facing in the width direction of the railway vehicle. 2. The railway vehicle according to claim 1,
The resistance reducing member is
a connection portion connected to the center beam and spaced apart in a longitudinal direction of the railcar;
a horizontal portion connected to a lower end of the connection portion and provided along the longitudinal direction of the railway vehicle. The railway vehicle according to claim 2,
a thickness of the horizontal portion in a width direction of the railway vehicle is equal to or smaller than a thickness dimension of the wheel,
A railway vehicle, characterized in that a lower end of the horizontal portion does not contact a top of the rail. 3. The railway vehicle according to claim 2,
a horizontal portion having a width extending from the wheel tread to the vicinity of the wheel tread, the horizontal portion having a slope that faces the wheel tread and is spaced from the wheel tread and inclined with respect to the longitudinal direction of the railway vehicle; 2. The railway vehicle according to claim 1,
The resistance reducing member is
a connection portion extending a first length along a longitudinal direction of the railcar and connected to the center beam;
a horizontal portion extending along a longitudinal direction of the railcar by a second length longer than the first length; and
The railway vehicle, wherein the outer surfaces of the connection portion and the horizontal portion in the width direction of the railway vehicle are flush with each other. A train made up of a plurality of railcars, including at least one railcar according to any one of claims 1 to 5. In the train of claim 6,
The rail cars at both ends of the train are
a bogie provided with the resistance reducing member at both ends of the train;
and a bogie located at a center side of the train body and not including the resistance reduction member. In the train of claim 7,
A train of vehicles, characterized in that the railway cars other than those at both ends of the train of vehicles have only bogies that are not equipped with the resistance reduction member.

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