JP4430880B2 - Projection for electrostatic antenna of high-speed traveling vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to the shape of a covering member that covers an external projection member such as an electrostatic antenna or an extra-high cable in a high-speed traveling vehicle such as a Shinkansen (registered trademark) , and more particularly to the static of a high-speed traveling vehicle that reduces aerodynamic noise during traveling. The present invention relates to a projection for an electric antenna.
[0002]
[Prior art]
In the problem of outside noise of a railway vehicle traveling at high speed, reduction of noise generated from around the vehicle, particularly aerodynamic noise such as wind noise generated during traveling is a major issue. This aerodynamic sound is generated when an air flow hits each part of the outer surface of the vehicle, and the cause of the occurrence is a stepped part or corner part and a sharp curved part on the surface of the vehicle body, or the outside of the vehicle. Various parts such as a handle, a step board, an antenna, etc., which are provided in the above.
As a technique for reducing the aerodynamic noise caused by the stepped portion as described above, there is a “step shape on the vehicle body side surface of a high-speed vehicle” described in Japanese Patent Laid-Open No. 2001-58568 (hereinafter referred to as “Patent Document 1”). Also, as a countermeasure technique for reducing aerodynamic noise caused by corners and curved surfaces, “low aerodynamic sound moving body” described in Japanese Patent Laid-Open No. 7-17211 (hereinafter referred to as “Patent Document 2”) is known. .
[0003]
The technique described in Patent Document 1 applies a step shape on the vehicle body side surface to the side doorway 2, and the cross-sectional shape from the vehicle body outer surface 10 to the outer surface 3 a of the side sliding door 3 has a long axis as a side sliding door 3. (Refer to “0017” to “0019” and FIGS. 1 and 5 of Patent Document 1).
In the technique described in Patent Document 2, the surface of a part where air flow separation occurs in the outer surface of a moving body that moves at high speed has a net-like or slightly uneven structure (see “0005” in Patent Document 2). ”,“ 0006 ”and FIG. 1).
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-58568 [Patent Document 2]
Japanese Patent Application Laid-Open No. 7-17211
However, any of the above aerodynamic noise reduction techniques is applied to a stepped portion, a corner portion or a curved surface portion of a vehicle body, and does not correspond to a protruding portion protruding from the outer surface of the vehicle body such as a handle or an antenna. .
For example, the electrostatic antenna cover 930 attached to the outer surface of the roof of the vehicle body as shown in FIGS. 7 and 8 is inclined backward from the front to the top of the base portion 931 having a relatively wide lower end in a side view. The left and right side walls 9355 connecting the front surface portion 9351 and the rear surface portion 9350, and the left and right side walls 9355 connecting the front surface portion 9351 and the rear surface portion 9350. It is a thin plate-like box that is thin in the direction, and its upper part projects further rearward from the rear surface part 9350 by a round pipe-shaped projecting part 9353 so as to ensure a required facing length with respect to the overhead wire.
The horizontal cross section is such that the front face portion 9351 and the rear face portion 9350 are semicircular and the whole is nearly rectangular, and this cross section is gradually reduced toward the top.
[0006]
[Problems to be solved by the invention]
As a result of measuring the aerodynamic sound of the conventional electrostatic antenna cover 930 by a wind tunnel experiment, as shown by a one-dot chain line in FIG. 6, the wind speed corresponding to a traveling speed of 270 km / h has a peak near a frequency of 500 Hz. It was found that a lot of noise was generated. This is presumably because the air current causes large separation at both the front edge portion and the rear edge portion of the electrostatic antenna cover 930.
[0007]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a projection for an electrostatic antenna of a high-speed traveling vehicle that minimizes separation of air flow as much as possible in order to solve such a problem.
[0008]
[Means for Solving the Problems]
The projection for the electrostatic antenna of the high-speed traveling vehicle according to the present invention is formed integrally with the electrostatic antenna and protrudes upward from the roof of the railway vehicle, and has a thin plate shape in the vehicle width direction of the railway vehicle. Thus, the shape seen from the side of the vehicle is a trapezoid with a symmetrical inclination in the longitudinal direction of the vehicle body, the width gradually decreases from the bottom to the top surface, and the outer shape of the horizontal section extends the longitudinal direction of the vehicle. It is characterized by having an elliptical arc shape as an axis.
[0009]
Therefore, even if one train of vehicles travels at a high speed in both the upward and downward directions, the air flow acting on the covering member is substantially the same, so that substantially the same aerodynamic sound can be obtained. In addition, since the air abutting the front edge in the vehicle traveling direction flows along the elliptical arc-shaped side wall, separation of the air flow is minimized at both the front edge and the rear edge. Can be reduced.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of a projection for an electrostatic antenna of a high-speed traveling vehicle according to the present invention will be described below with reference to the drawings. The electrostatic antenna protrusion of the vehicle outer protrusion member in the high-speed traveling vehicle of the present embodiment is applied to the covering member of the electrostatic antenna provided on the leading and trailing vehicles of the Shinkansen.
Here, FIG. 1 is a side view of the leading vehicle of the high-speed traveling vehicle. 2 is a side view of the covering member, FIG. 3 is a plan view thereof, and FIG. 4 is a front view thereof.
[0011]
(Structure) The structure of the covering member of the electrostatic antenna according to one embodiment of the present invention will be described. As shown in FIG. 1, the covering member 30 of the electrostatic antenna (not shown) is an end portion (hereinafter referred to as “rear end portion”) near the next vehicle of the vehicle body 10 of the leading vehicle and the last vehicle of the high-speed traveling vehicle 1. .) Is attached to the outer surface 101 of the ceiling.
As shown in FIG. 2, the covering member 30 has a mountain shape that is symmetrical with respect to the center line p in the longitudinal direction of the vehicle in a side view, is formed at the lower end thereof, and has a flange portion 311 that expands left and right in a bowl shape. A hollow box body made of FRP comprising a pedestal 31 and an electrostatic antenna projection 35 standing upward from the center of the pedestal 31.
[0012]
The projection 35 for the electrostatic antenna has a trapezoidal shape that gradually decreases in length in the front-rear direction from the bottom 352 continuous to the pedestal portion 31 and reaches the top 353 in a side view. As shown in FIG. 5, an elliptical arc shape having the longitudinal direction of the vehicle as the major axis is continuous from the bottom 352 to the top 353.
Then, the electrostatic antenna projection 35 reaches the top 353 while the width (thickness) gradually decreases from the bottom 352 in the front view. The minor axis of the ellipses 351 and 351 becomes smaller toward the upper part, and the major axis forming the side wall 355 is also made smaller toward the upper part.
The length of the top portion 353 in the front-rear direction is substantially the same as the length from the upper end of the front edge portion 9351 of the conventional covering member 930 to the rear end of the pipe portion 9353 protruding rearward.
The pedestal 31 is provided with a number of attachment holes 314 for attaching the covering member 30 to the ceiling by the outer surface 101 of the vehicle body 10.
[0013]
(Operation) Next, the operation of the electrostatic antenna projection 35 of the vehicle outer projection member in the high-speed traveling vehicle of the present embodiment will be described.
As the vehicle travels at high speed, air comes into contact with the front edge 351 of the covering member 30, and air flows along the side walls 355 on both sides from the front edge 351 having an elliptical short diameter so as to cut the air. To do.
Since the front edge portion 351 has an elliptical short diameter, the air flow smoothly flows along the side walls 355 on both sides at the front edge portion 351, and separation hardly occurs. The air flow that has flown without separation at the front edge portion 351 symmetrical to the front edge portion 351 is merged again without being largely separated, and flows backward.
[0014]
Therefore, vortices due to separation of the air flow causing aerodynamic noise hardly occur, and as a result, aerodynamic noise can be reduced. The result of noise measurement for demonstrating this effect will be described.
In other words, this noise measurement gives a wind speed equivalent to 270 km / h, the running speed of the Shinkansen “ Nozomi (registered trademark) ”, in a low-noise wind tunnel installed in the Railway Technical Research Institute located in Yonehara-cho, Shiga Prefecture. This is a result of measurement performed at 3.5 m on the side of the covering member.
As a result, as shown by the thick solid line in the graph of FIG. 6, it was found that the noise during traveling at 270 km / h can be reduced by about 12 dBA compared to the conventional covering member 930.
[0015]
As described above, the electrostatic antenna protrusion 35 of the high-speed traveling vehicle 1 of the present embodiment has a planar cross-sectional shape that is symmetric with respect to the center line p in the vehicle front-rear direction, and is an elliptical arc that is long in the vehicle front-rear direction. As a result, the flow of air during high-speed traveling is not separated, and therefore aerodynamic noise can be reduced, and this effect can be exhibited when traveling either before or after the high-speed traveling vehicle 1. .
[0016]
In addition, this invention is not limited to the thing of the said embodiment, A various change is possible in the range which does not deviate from the meaning.
For example, in the above-described embodiment, the example in which the shape of the covering member is applied to the covering member of the electrostatic antenna has been described. However, the present invention is not limited to this, and it faces the outer surface of the ceiling portion such as the fourth and fifth cars of the Shinkansen vehicle. It is also possible to apply to a covering member that covers the cable head of the extra high cable provided in the cable.
Further, it is also possible to make the horizontal cross-sectional shape of a relatively low projection member such as a direct joint of a special cable or a communication antenna provided at both ends of the vehicle other than the cable head into an elliptical arc shape.
[0017]
【The invention's effect】
The present invention provides a projection for an electrostatic antenna of a high-speed traveling vehicle that is integrally formed with an electrostatic antenna and protrudes upward from the roof of the railway vehicle, and has a thin plate shape in the vehicle width direction of the railway vehicle, The shape seen from the side is a trapezoid with a symmetrical inclination in the longitudinal direction of the car body, the width gradually decreases from the bottom to the top, and the outer shape of the horizontal section is an elliptical arc shape with the longitudinal direction of the vehicle as the major axis Therefore, it is possible to minimize the separation of the air from the covering member due to the air flow generated when the high-speed vehicle is traveling at high speed, and as a result, it is possible to reduce aerodynamic noise.
[Brief description of the drawings]
FIG. 1 is a side view of a high-speed traveling vehicle according to an embodiment of the present invention.
FIG. 2 is a side view of a covering member applied to a high-speed traveling vehicle according to an embodiment of the present invention.
FIG. 3 is a plan view of a covering member applied to a high-speed traveling vehicle according to an embodiment of the present invention.
FIG. 4 is a front view of a covering member applied to a high-speed traveling vehicle according to an embodiment of the present invention.
5 is a cross-sectional view taken along line VV in FIG.
FIG. 6 is a graph showing the results of a noise test in a low-noise wind tunnel of a covering member according to an embodiment of the present invention and a conventional covering member.
FIG. 7 is a side view of a conventional covering member.
FIG. 8 is a plan view of a conventional covering member.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 High speed traveling vehicle 10 Car body 20 Protrusion member 30 Cover member 31 Base part 35 Electrostatic antenna protrusion 351 Front edge part 355 Side wall

Claims (1)

In the projection for the electrostatic antenna of the high-speed traveling vehicle formed integrally with the electrostatic antenna and protruding upward from the roof of the railway vehicle,
It is a thin plate shape in the vehicle width direction of the railway vehicle, and the shape seen from the side surface of the vehicle is a trapezoid whose symmetry in the longitudinal direction of the vehicle body is symmetrical, and the thickness gradually decreases from the bottom to the top surface. A projection for an electrostatic antenna of a high-speed traveling vehicle, wherein the outer shape of the horizontal section is an elliptical arc having a longitudinal axis of the vehicle as a major axis.

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