JP2000069602A - Current collector boat for pantograph - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a collector shoe for a pantograph, wherein noise is low and lift does not change to an ang1e of attack and is stable. SOLUTION: Magnifying trenches 1b for mgnifying an air flow parallel with the travelling direction of a vehicle, and contracting trenches 1a for contracting an air flow parallel with the travelling direction of the vehicle are installed on the lower surface of a collector shoe 1. With this constitution, vortex vibration of a flow which is caused by the contracting trenches 1a and the magnifying trenches 1b and vortex vibration due to a protruding section part are made to interfere with each other, and regularity of vortex vibration can be disturbed, so that the noise level can be lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The aerodynamic noise generated from a hull is increasing along with the speeding up of vehicles. Particularly, in recent years, the speeding up of Shinkansen is planned, and the development of low-noise pantographs complying with noise regulations is also a major object. It has become one of. The present invention relates to a current collector of a pantograph installed on the roof of the high-speed electric vehicle, that is, a current collector boat, and more particularly to a current collector for a pantograph with reduced noise.

[0002]

2. Description of the Related Art FIG. 4 shows a configuration of a pantograph current collector used in a conventional Shinkansen. In FIG.
Is a side view, and (b) is a view of the current collector viewed from below. As shown in the figure, the current collector for the pantograph is a current collector boat 1
And horn 2 attached to both ends, and current collector boat 1
Is constituted by a slide plate 3 attached to the upper surface of the slab.

FIG. 5A is a view showing a cross section of a current collector boat. As shown in FIG. 5, the conventional current collector boat has a uniform angular cross section. This cross-sectional shape is intended to stabilize the lift characteristics generated by the flow of air, and little consideration has been given to dealing with the noise problem. FIG. 5B shows an example of a cross-sectional shape of a current collector boat designed to reduce noise. This shape is one of those in which the cross-sectional shape is streamlined with respect to the flow of air so as not to disturb the flow around the current collector boat, thereby reducing noise. However, the cross-sectional shape shown in FIG. 5B actually has a tendency that lift is easily generated with respect to the flow, and the lift value is sensitive to the angle of attack of the air flow. Further, since the grounding plate is attached to the upper surface of the current collector boat horizontally, there is a problem in the shape of the current collector boat, and practical use is difficult.

[0004]

SUMMARY OF THE INVENTION The characteristics of the current collector hull of a pantograph required for a high-speed vehicle can be described in a nutshell.
Low noise and stable lift with no change with respect to angle of attack. The streamline shape shown in FIG. 5 (b) is a shape that does not easily generate noise in that it does not disturb the flow of air.
However, the results of many studies have shown that this shape is prone to lift, as applied to airplanes, etc., and has the characteristic that lift responds sensitively to the angle of attack of the flow. Therefore, the above request cannot be fully answered. Further, as described above, there is a problem with the shape of the current collector boat, and practical use is difficult. The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a pantograph current collector boat with low noise and a stable lift with no change with respect to the angle of attack. It is.

[0005]

The rectangular cross section generates a vortex with respect to the flow of air, and the vortex acts as a sound source to generate noise.
Before describing the shape, the mechanism of aerodynamic noise will be briefly described. As a general theoretical example, the flow for a cylinder is illustrated in FIG. That is, when a cylinder is placed in a flow, vortices having a constant period determined by the size of the cylinder and a certain flow velocity are regularly generated behind. This vortex is well known as Karman vortex.

According to the same theory, the same can be said for a prism, and this vortex becomes a regular oscillating flow with turbulence, and this regular oscillating flow enhances sound and increases aerodynamic sound. Therefore,
A method for disturbing the regularity and weakening the sound was studied. First, we considered changing the cross-sectional dimension of the prism. However, in practice, the upper surface of the current collector boat is a surface that slides on the overhead wire and needs to be flat. Therefore, further studies were conducted, and as shown in FIGS. 7 and 8, irregularities were formed on the lower surface of the current collector boat, and a prototype having a partially different cross-sectional shape was manufactured. 8A is a perspective view of the current collector boat 1, and FIG. 8B is a diagram of the current collector boat 1 viewed from below (in the direction A in FIG. 8A). The indicated portion is a concave portion. FIG. 7 shows the current collector boat 1 shown in FIG.
7A and 7B show a pantograph current collector in which horns 2 are attached to both ends and a grinding plate 3 is attached to an upper surface, and FIG. 7A is a side view and FIG.

[0007] With the above structure, the vortex vibration of the regular flow in the concave section and the vortex vibration of the regular flow in the convex section interfere with each other to disturb the regularity of the vortex vibration, and the sound volume is increased. Although the sound quality could be reduced to some extent, various techniques for further reducing the sound volume were examined. As a result, as shown in FIG. 9, even if the concaves and convexes have the same irregularities, not only the concaves or convexes are simply arranged in parallel with the flow, but also the groove dimensions of the concaves are enlarged or reduced in the flow direction. It has been clarified that the loudness of the sound can be further reduced by adopting a simple shape (the hatched portion in FIG. 9 is a concave portion). That is, in the configuration shown in FIGS. 7 and 8, two types of vortex interference are generated due to the unevenness, but by making the shape of the uneven portion oblique as shown in FIG. 9, the effect of disturbing the three types of flow is obtained. Was generated (actually, a more complicated air flow was generated), and the noise could be further reduced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a view showing the structure of a pantograph current collector according to an embodiment of the present invention. FIG. 1 (a) is a side view, and FIG. 1 (b) is a view seen from below. is there. In the figure, reference numeral 1 denotes a current collector boat, and a top plate 3 is provided with a sliding plate 3 and horns 2 are provided at both ends. In addition, current collection boat 1
As shown in FIG. 4B, an enlarged groove 1b for expanding the flow of air parallel to the traveling direction of the vehicle and a reducing groove 1a for reducing the flow of air parallel to the traveling direction of the vehicle, as shown in FIG. Is provided.

The noise generated by the wind tunnel test was compared and evaluated for the pantograph current collector shown in FIG. 1 and the pantograph current collector shown in FIG. FIG. 2 shows a configuration of a pantograph in which the above-mentioned current collector was attached and tested.
FIG. 2 shows a single-arm type pantograph for a Shinkansen bullet train, 1 is a current collector boat, 2 is a horn, 3 is a slide plate,
Reference numeral 4 denotes a boat support, and the current collector boat 1 is supported by the framework 5 via the boat support 4. The single arm type pantograph is asymmetric with respect to the traveling direction and the air flow differs depending on the traveling direction. Normally, the flow of air to the pantograph is indicated by the arrow A in the figure as the "fluttering direction",
The opposite direction is called "anti-fluttering direction".

[0010] In the present invention, a wind tunnel test was performed using a test pantograph of one fifth of the actual machine to perform comparative evaluation.
A wind tunnel test was conducted at a wind speed of 300 km / h using a test pantograph equipped with the current collector boat of the present invention and the current collector boat of the present invention. As a result, compared with the case of using the conventional current collector boat,
When the current collecting boat body of the present invention is used, about 0.
The noise level decreased by 9 dB and 0.8 dB in the anti-fluttering direction. The noise data of the current collecting boat body having the parallel grooves shown in FIGS. 7 and 8 is omitted because it is located between the conventional product and the present invention.

FIG. 3 is a diagram showing the results of frequency spectrum analysis of noise generated from a conventional pantograph equipped with a current collecting boat body and the current collecting boat body of the present invention. FIG. 3A shows the noise level for each frequency when air flows in the pantograph fluttering direction of the current collector boats of the conventional product and the invention, and FIG. The horizontal axis indicates the frequency (Hz), the vertical axis indicates the noise level, and one graduation on the vertical axis is 5 dB. As shown in FIG. 3, the noise level of the product of the present invention is generally lower than that of the conventional current collector boat, and in particular, the narrow-band sound noise around the frequency of 200 Hz is significantly reduced. This shows the effect of providing the groove as in the present invention on the lower surface of the current collector boat, whereby the regularity of vortex generation was lost and noise was reduced.

[0012]

As described above, in the present invention, a plurality of grooves penetrating from the front surface to the rear surface in the traveling direction of the vehicle are provided on the lower surface of the current collector boat, and the grooves are formed with respect to the traveling direction of the vehicle. Groove shaped to expand parallel air flow (enlarged groove)
And a groove having a shape to be reduced (reduced groove), and the enlarged groove and the reduced groove are arranged repeatedly next to each other, so that the noise generated by the pantograph can be reduced by a relatively simple configuration change. Can be

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a pantograph current collector according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration of a pantograph in which a current collector according to an example of the present invention is attached and tested.

FIG. 3 is a diagram showing a frequency spectrum analysis result of noise generated from a test pantograph equipped with a current collector boat of a conventional product and a product of the present invention.

FIG. 4 is a diagram showing a configuration of a pantograph current collector used for a conventional Shinkansen.

FIG. 5 is a diagram schematically showing a cross section of a current collector boat.

FIG. 6 is a diagram illustrating a vortex generated when a cylinder is placed in a flow.

FIG. 7 is a diagram showing a configuration of a pantograph current collector in which grooves are provided in parallel on a lower surface.

8 is a diagram showing a current collector boat of the pantograph current collector shown in FIG.

FIG. 9 is a diagram showing a current collector boat having a shape such that a groove dimension expands and contracts in a flow direction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Current collecting boat body 1a Reduction groove 1b Enlargement groove 2 Horn 3 Slip board 4 Boat support 5 Frame

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yuichi Sasaki 2-2-2 Yoyogi Shibuya-ku, Tokyo East Japan Railway Company (72) Inventor Masayuki Onodera 2-11-3 Hayakawa, Odawara City, Kanagawa Prefecture (72) Inventor Hiroyuki Arai 3-8-8 Fukuura, Kanazawa-ku, Yokohama-shi, Kanagawa F-term (reference) 5H105 AA14 BA02 BB01 CC02 CC12 DD04 EE02 EE03 EE13

Claims (1)

[Claims] 1. A pantograph current collector installed on a roof of an electric vehicle, wherein a plurality of grooves penetrating from a front surface to a rear surface in a traveling direction of the vehicle are provided on a lower surface of the current collector boat, The groove is formed of a groove shaped to expand the flow of air parallel to the traveling direction of the vehicle, and a groove shaped to reduce the flow of the air. Are arranged repeatedly adjacent to each other.