JP2916759B2 - Windproof cover for current collector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Definition Items] In this specification, "front, rear, left, and right" refer to front, rear, left, and right with respect to the traveling direction of the vehicle, respectively.

[0002]

BACKGROUND OF THE INVENTION The present invention relates to a method for reducing aerodynamic noise generated from a current collector installed on a roof of a railway vehicle.
A windproof cover installed so as to surround a current collector is intended to reduce pressure fluctuations caused by the windproof cover during running of a vehicle.

[0003]

2. Description of the Related Art In order to increase the speed of railway vehicles, various attempts have been made to alleviate adverse effects on the roadside environment, particularly noise, as much as possible. The present applicant has focused on a current collector installed on a vehicle roof as a noise source during running of the vehicle, and to reduce aerodynamic noise generated from the current collector,
We are taking measures from the following two directions. That is, it is an improvement in the shape of the current collector and the form of the windproof cover surrounding the current collector.

With respect to the shape of the current collector, the hull has a wing shape, and the support portion of the hull has a columnar structure or a single-arm type pantograph structure.

[0005] As shown in FIG. 3, the windproof cover has slope portions 11, 11 formed of a gentle inclined plane formed before and after the current collector 20, and side walls provided on both right and left sides of the current collector 20. The one configured with the unit 12 is conventionally employed. In this form, the hull 21 has a wing shape, so that it is easily affected by the wind.
The purpose of this method is to stabilize the flow of the wind hitting the windshield, reduce the adverse effect of the wind on the boat body 21, and reduce the aerodynamic sound level generated from the windbreak cover 10 itself.

[0006]

Since a railway vehicle travels while pushing air away, it causes pressure fluctuations around the vehicle body due to wind pressure. This pressure fluctuation adversely affects the surrounding environment, such as vibration and noise. In addition, when passing the oncoming train, both the own vehicle and the other vehicle may suffer undesired effects such as vibration. Furthermore, when the train enters the tunnel, the pressure fluctuation propagates forward in the traveling direction as a pressure wave due to the surrounding wall being closed by the tunnel wall, and an impulsive sound is generated at the tunnel exit side.

It is natural that the pressure fluctuation is most remarkable at the head of the vehicle, but also occurs at the installation position of the windproof cover. This is because the cross-sectional shape in the direction perpendicular to the vehicle traveling direction changes before and after the windbreak cover.

[0008] The following two conditions are provided for reducing the pressure fluctuation caused by the windbreak cover 10. One of them is to make the area (hereinafter, referred to as “projection area”) of the windproof cover 10 when viewed from the front perpendicular to the vehicle traveling direction as small as possible. The other is that the rate of change of the area from the end of the windbreak cover 10 to the position where the cross-sectional area in the direction perpendicular to the vehicle traveling direction is maximum (usually the position of the central hull 21) is very small. That is, the value is kept as small as possible without fluctuation.

With respect to the projected area of the windproof cover 10, it is necessary to secure an insulating separation between the inner surface of the windproof cover 10 and the horn 23 projecting to the side of the boat 21 and the insulator 22 supporting the current collector 20. Due to the nature and necessity of securing a work space for maintenance and inspection around the current collector 20, there is a limit to the range that can be reduced.

As for the other condition, that is, the rate of change of the cross-sectional area of the windproof cover 10, as a method of keeping the change rate constant and as small as possible, it is conceivable to extend the slope portion 11 back and forth. However, if the overall length of the windproof cover 10 is increased by extending the slope portion 11, the weight of the windproof cover 10 increases, resulting in an increase in vehicle weight and an increase in the position of the center of gravity. An increase in vehicle weight causes an increase in ground vibration, and an increase in the position of the center of gravity causes a problem of deterioration in running stability. In addition, when the windproof cover 10 is enlarged, a new problem that fatigue breakage is likely to occur due to vibration or the like arises. Therefore, the formation length of the slope portion 11 is naturally limited.

For the reasons described above, the conventional windproof cover 10 cannot be said to be satisfactory with respect to the mitigation of pressure fluctuations. The development of is desired.

[0012]

SUMMARY OF THE INVENTION The present invention is directed to a windproof cover created in view of the above-mentioned conventional problems, and is characterized by having the following form. That is, substantially the entire outer surface is formed into a continuous curved surface, and the cross-sectional area of the windproof cover in the direction perpendicular to the vehicle traveling direction is continuous from the front end and the rear end toward the hull position. to an increase, it is set to be maximum in the collector head position, and changes the graph along the vehicle traveling direction of the cross-sectional area of the third straight line region
It is formed to include about one.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One of the features of the windproof cover according to the present invention is that substantially the entire outer surface is formed into a continuous curved surface. Here, “substantially the whole” refers to FIGS. 1 and 2
As shown in (2), since the region where the current collector 20 is installed is the concave portion 2, it means that the concave portion 2 and a limited portion around the concave portion 2 do not necessarily have to be curved.

The "continuous curved surface" is generally a convex curved surface, and does not include, in principle, flat surfaces, corners, ridges and the like.
However, as long as there is no possibility of adversely affecting the noise reduction function and the pressure fluctuation, such as the periphery of the concave portion 2, if necessary, a flat portion or a concave curved surface may be locally included. Do not hinder.

Another feature of the present invention is that the windproof cover 1
The cross-sectional area in the direction perpendicular to the vehicle traveling direction at
That it is set to increase continuously from the front end and the rear end toward the hull position, and that the cross-sectional area is set to be maximum at the hull position, and that the change graph of the cross-sectional area is a straight line That is, the area is set to include about one third .

The windproof cover of the present invention constructed as described above is substantially entirely formed of a curved surface, the cross-sectional area of which gradually increases from the end toward the center hull position, and the rate of change of the cross-sectional area is very small. The shape is changed so that it does not fluctuate greatly and the change graph of the cross-sectional area includes about one third of the linear region.
As a result, it is possible to suppress the pressure fluctuation during traveling of the vehicle as compared with the related art without reducing the projection area as compared with the related art.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the drawings showing embodiments. FIG. 1 shows a windproof cover 1 according to the present invention.
FIG. 2A and FIG. 2B are perspective views showing one embodiment of the present invention.
It is the top view and side view of the windbreak cover 1, respectively.

The current collector 20 is based on the premise that the boat 21 has a wing shape and the boat support 24 has a columnar structure or a single arm structure.

The illustrated windbreak cover 1 has a substantially curved outer surface except a periphery of a concave portion 2 formed in a central region for installation of the current collector 20, and has a curved surface in the vehicle traveling direction. The cross-sectional area in the vertical direction is set so as to gradually increase toward the center hull position, and that the rate of change does not change much. Therefore, the overall shape of the windproof cover 1 according to the present embodiment can be said to be a shape as if the bottom of the ship were inverted and the concave portion 2 was formed in the central region.

Since the windproof cover 1 is required to be strong and durable, its materials include aluminum alloys such as aluminum and duralumin, titanium alloys and other light alloys, stainless steel, FRP, GRP, and plastics. Aluminum or aluminum alloys are considered to be suitable in terms of properties and price.

The windproof cover 1 may be made entirely of a single member, or may be formed by combining a plurality of parts on a vehicle roof.

The notches 3 formed on the left and right sides in the vicinity of the center of the windproof cover 1 are provided with horns that project to the left and right of the boat body 20 when the columnar support portion 24 of the current collector 20 is folded on the vehicle roof. This is for securing insulation separation between the portion 23 and the windproof cover 1.

In this embodiment, as shown in FIG.
In the regions R1 and R3 from the front end and the rear end to the vicinity of the concave portion 2, the side surface shape has a rising gradient of the angle α, and the height dimension is constant in the central region R2 where the concave portion 2 is formed. Is formed. Further, as shown in FIG. 2B, the planar shape is formed such that the width W continuously increases from the front end and the rear end to the center hull position.

Based on such a configuration, the windproof cover 1 of the present embodiment moves from the front end or the rear end toward the center hull position.
In the regions R1 and R3 on both end sides, the cross-sectional area increases at a relatively large rate of increase, but the cross-sectional area also increases in the central region R2 due to the increase in the width dimension W.
2, the rate of change of the cross-sectional area can be suppressed lower than before.

The rate of change of the projected area can be reduced as the ratio of the regions R1 and R3 having the gradient α to the windproof cover 1 increases, but it is necessary based on the size of the current collector 20. Since the minimum formation range of the concave portion 2 is defined, the ranges of the front and rear regions R1 and R3 are determined accordingly.

An example of the outer dimensions of the windproof cover 1 is shown in FIG.
m, height 650 mm from the vehicle roof at the center position,
Maximum width dimension at center position 1900 mm, R1 and R
2, the formation length of each is 3200 mm, and the inclination α of the front and rear ends when viewed from the side is about 10 to 15 °.

The windproof cover 1 of the present invention shown in FIG.
Compared with the conventional windproof cover 10 shown in FIG. 1, the windproof cover 1 of the present invention has substantially the entire outer surface formed of a curved surface, whereas the conventional windproof cover 10 has a slope portion 11 and a side surface 12. Both are different in that they are formed from a plane. Looking at the change of the cross-sectional area ,
As shown in the graph , the cross-sectional area (shown by a broken line) of the windproof cover 1 of the present invention gradually and continuously increases from both ends toward the center hull position , and From the front and rear ends
The area of about 2 m of about 1.3 to 3.3 m respectively is actual.
It is a qualitative straight line. That is, the windproof cover 1 of the present invention.
Is the area where the change graph of the cross-sectional area is about 1/3 of the total length
Is a straight line. In contrast, conventional windbreak
The cross-sectional area of the bar 10 (shown by a solid line) increases at a large change rate only in a range corresponding to the slope portion 11, and does not change after reaching the maximum value. Based on these differences
In the windproof cover 1 according to the present invention, the total length and the maximum cross-sectional area are equal to those of the related art, and the change rate of the projected area can be suppressed smaller than that of the related art.

Based on the above-mentioned difference, the windbreak cover 1 according to the present invention has less pressure fluctuation than the conventional one. FIG. 5 is a graph showing a general waveform of the pressure fluctuation observed on the exit side of the tunnel when the train enters the tunnel. As shown in the graph, after the pressure fluctuation P ₀ larger by the vehicle front part at the tunnel inrush occurs, then a small pressure variation ΔP by wind cover (= P ₁ -P ₂₎ was observed, the pressure of the last vehicle tail Fluctuation is a general pattern of pressure fluctuation. When a windbreak cover was mounted on the vehicle and a pressure fluctuation measurement test was performed, the pressure fluctuation value ΔP = P ₁ -P ₂ generated at the tunnel exit side when the vehicle entered the tunnel at about 300 km / h was calculated as
It was about 19 Pa in the conventional windproof cover. On the other hand, in the windproof cover of the present invention, ΔP could be reduced to about 11 Pa.

By the way, even if the windproof cover according to the present invention is excellent in the effect of suppressing pressure fluctuations, practicality is lost if the aerodynamic noise generated from the windproof cover itself is much larger than the conventional windproof cover. Therefore, when a wind tunnel test was performed, the result was obtained that the windproof cover according to the present invention did not have a great difference in aerodynamic sound level as compared with the conventional windproof cover, but rather reduced.

The procedure of the wind tunnel test is as follows. The windproof cover 20 according to the present invention shown in FIGS.
1 / M model (length 600 mm x width 95 mm x height 3
2.5 mm) and a 1/20 model N (600 mm long × 80 mm wide × 32.5 mm high) of the conventional windproof cover shown in FIG. Attach to

The measurement of the aerodynamic noise is performed at a speed of 40 m / sec from the wind tunnel F.
(144 km / h) is sent by a microphone installed at a position approximately 500 mm laterally from the center of the windbreak cover and corresponding to the height of the hull, as shown in FIG.

As a result of the wind tunnel test, the windproof cover of the present invention
When converted to an actual vehicle, the peak of the aerodynamic sound level near 300 Hz was reduced by about 6 dB from that of the conventional windbreak cover, and was suppressed to the same level in other frequency bands.

Further, in a state where the hull of the current collector surrounded by the windproof cover is at the standard working height (5000 mm), it is assumed that the hull is placed in the air flow having the main flow velocity v ₀ , the flow velocity of the wind and v ₁ falls, the flow velocity v ₁ /
When the value of the main flow velocity v ₀ was obtained by simulation calculation, the windproof cover of the present invention showed that v ₁ / v ₀ = about 1.04
While there was a, the conventional wind cover becomes v ₁ / v ₀ = about 1.06. From this simulation result, the form of the windbreak cover according to the present invention does not increase the wind speed hitting the hull as compared with the conventional case, and therefore, there is little possibility that the fluctuation of the lift of the hull will be adversely affected. It is understood that it does not cause the level to rise.

[0034]

As is apparent from the above description, the windproof cover according to the present invention can alleviate the pressure fluctuation that occurs when the vehicle is running, and impair the aerodynamic noise reduction effect as compared with the conventional one. Never. Therefore, the present invention can minimize the influence on the roadside environment, and greatly contributes to the realization of high-speed running of railway vehicles exceeding 300 km / h.

Further, the windproof cover according to the present invention does not reduce the projection area as compared with the conventional case, although the rate of change of the cross-sectional area can be reduced, so that a concave area necessary for installing the current collector is secured. can do.

[Brief description of the drawings]

FIG. 1, showing an embodiment of the present invention, is a perspective view of a windproof cover installed on a vehicle roof.

FIG. 2 shows one embodiment of the present invention, and (A)
2 is a side view of the windproof cover, and FIG. 2B is a plan view of the windproof cover.

FIG. 3 is a perspective view showing a conventional windbreak cover.

A wind cover and a graph showing a change situation along the vehicle traveling direction of the cross-sectional area of the conventional wind cover according to the present invention; FIG.

FIG. 5 is a graph showing pressure fluctuations observed at a tunnel exit side when a vehicle enters a tunnel.

6A and 6B show a procedure for conducting a wind tunnel test using a 1/20 model, wherein FIG. 6A is a plan view showing a state in which a windproof cover model according to the present invention is installed in a wind tunnel, and FIG. FIG. 2C is a plan view showing a conventional windproof cover model, and FIG. 2C is a side view showing a situation where the windproof cover model according to the present invention is installed in a wind tunnel.

FIG. 7 is a front view showing a measurement position of aerodynamic noise in a wind tunnel test using a 1/20 model.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Windproof cover 2 Concave part 3 Notch 20 Current collector 21 Boat body 22 Insulator 23 Horn part 24 Support part

────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Fujio Horie 3-9-60 Inada Shinmachi, Higashiosaka City Kinki Vehicle Co., Ltd. (56) References Japanese Utility Model 6-60201 (JP, U) (58) Survey Field (Int.Cl. ⁶ , DB name) B60L 5/00-5/42

Claims (1)

(57) [Claims] 1. A windproof cover surrounding a current collector installed on a roof of a railway vehicle, wherein substantially the entire outer surface of the windproof cover is formed as a continuous curved surface, and sectional area in the direction perpendicular to the vehicle traveling direction of the cover,
It increases continuously from the front end and the rear end toward the hull position.
Te is set to be the largest in the collector head position,
In addition, the change graph of the cross-sectional area along the vehicle traveling direction is straightforward.
A windshield cover for a current collector, wherein the windshield cover is formed so as to include about one third of a line region .