JP5468233B2 - Low noise hinge cover device for high-speed railway pantograph - Google Patents

Description

The present invention Shinkansen, etc., are installed on the roof of an electric railway vehicle traveling at high speed, about noise suppression techniques of pantograph graph device for receiving power from the overhead wire.

  In order to increase the speed of railway vehicles, it is essential to meet environmental standards for noise along the railway. For railway noise, depending on the sound source, rolling noise generated from the interaction between rails and wheels, current aerodynamic noise generated from current collectors such as pantographs, and vehicle upper aerodynamic noise generated from the upper part of the vehicle such as the vehicle spacing, It can be classified into structure noise that causes vibrations of the structure. In particular, since the sound intensity of aerodynamic noise is proportional to the sixth power of the train speed (for example, Non-Patent Document 1), reduction of aerodynamic noise is required in order to further increase the speed of the train.

  A pantograph device installed above the roof of a railway vehicle has a current collecting boat that contacts the overhead line and takes in electric power, and a support mechanism that elastically supports the current collecting boat. Conventionally, there are rhombus, lower frame crossing, etc. as this type of support mechanism. However, in recent years, considering the reduction of airflow noise generated during operation, it is so-called as used for high-speed railway vehicles such as Shinkansen. A single arm structure is used.

  An example of the pantograph for the high-speed train of the single arm structure is shown in FIG. In the figure, 1 is a hull in contact with the overhead wire 10, 2 is an upper frame that supports the hull 1, 3 is a lower frame that is attached to the roof side of the railway vehicle, and 4 is an upper frame 2 and a lower frame 3. A hinge cover 5 for covering the hinge portion is a protective cover for protecting a lever portion and the like below the lower frame 3.

  Pantographs have been studied for noise reduction by various engines, and as a noise source, the boat body 1 in the fluttering direction (the direction going to the right in FIG. 1) and the boat body 1 the anti-fluttering direction (the direction going to the left in FIG. 1) ), It is known that the hinge cover 4 is a main sound source (for example, Patent Documents 1 and 2 and Non-Patent Document 2). Many studies (for example, non-patent document 3) have been made on the hull 1 so far, and a reduction measure has been proposed.

  On the other hand, Patent Document 3 has a base frame that is insulated and supported on a roof surface of a railway vehicle via an insulator, and has a through hole that allows a part of the upper and lower surfaces to communicate with each other, and is provided above the base frame. Furthermore, an intermediate cover made of an insulating material, and a pantograph frame provided on the upper surface of the base frame so as to be able to rise and fall, the upper part of which protrudes above the intermediate cover through a through hole, and the upper end of the pantograph frame are supported The collector boat device is provided at a position where the intermediate cover is sandwiched between the front and rear sides of the railway vehicle on the roof surface, and the front and rear ends of the space where the insulator and the base frame are installed between the lower surface of the intermediate cover and the roof surface. There is described a pantograph apparatus that includes a pair of end covers, each of which is made of an insulating material, and in which the upper surface of both end covers and the upper surface of the intermediate cover are smoothly connected. With this configuration, the wind is not applied to the portions covered by the intermediate cover and the end cover, and the generation of airflow noise during high-speed traveling is suppressed.

  Patent Document 4 discloses a support member attached on the roof surface of a railway vehicle, a horizontal axis provided on the support member in the width direction of the railway vehicle, and a lower end portion by one end portion of the horizontal axis. A pantograph device including a pantograph frame that is supported in a cantilever manner so as to be swingable and displaceable and supports a current collecting boat at an upper end portion, and a tilting mechanism for tilting the pantograph frame is described. . And the raising / lowering mechanism provided in the upper surface of the support member is covered with the cover, and the pantograph frame is formed on the part protruding from the cover through the through hole formed on one side of the cover at one end of the horizontal axis. The lower end is supported. With this configuration, airflow noise generated during high-speed traveling is suppressed.

  Patent Document 5 includes a base frame that is insulated and supported on the roof surface of a railway vehicle, and a through hole that allows the upper and lower surfaces to communicate with each other, and is made of an insulating material provided above the base frame. A cover, a pantograph frame provided on the upper surface of the underframe so that it can be raised and lowered, with its upper portion protruding above the cover in a state of being inserted through a through hole, and a current collector boat supported by the upper end of the pantograph frame And the through hole has a shape that is long in the displacement direction of the pantograph frame so as to allow the displacement of the pantograph frame, and at the opening between the peripheral edge of the through hole and the outer peripheral surface of the pantograph frame facing the peripheral edge, There is described a pantograph device provided with a second cover that closes the opening regardless of the displacement of the pantograph frame during operation of a railway vehicle. By providing this second cover, airflow noise generated in the through hole portion is reduced regardless of the displacement of the pantograph frame.

JP 11-178105 A JP 11-178106 A JP 2004-274986 A Japanese Patent Laid-Open No. 2005-65350 JP 2005-130595 A Takehisa Takaishi, Journal of the Gas Turbine Society of Japan, 33-6 (2005-11), p52 Kazuhiko Tezuka, Abstracts of Lecture Meeting, Railway Research Institute, (2005), p55 Mitsuru Ikeda, two others, Railway Research Institute report, Vol. 18, no. 18, (2004-8), p23

  The noise suppression techniques proposed in the above Patent Documents 3 to 5 can be applied to newly manufactured high-speed electric railway vehicles. However, we are trying to increase the speed of a railway vehicle having a pantograph structure with a hinge portion exposed, such as the structure shown in FIG. 1 that is already running (for example, increasing the speed from 300 km / hour to 350 km / hour). In this case, the aerodynamic noise that was within the environmental standard value at the current speed may exceed the environmental standard value due to high speed traveling. As described above, since the sound intensity of aerodynamic noise is proportional to the sixth power of the train speed, measures for reducing aerodynamic noise are required even when the speed of existing vehicles is increased. It is difficult in terms of cost to remodel all the vehicles to be speeded up so that the hinge part is not exposed to the outside.

  Accordingly, the present invention has been conceived based on the results of elucidation of acoustic characteristics and identification of a sound source, focusing on the hinge portion of a high-speed rail pantograph, and a high-speed rail pantograph capable of reducing aerodynamic noise. An object of the present invention is to provide a low noise hinge cover device for use.

In order to solve the above-mentioned problems, a low-noise hinge cover device for a high-speed railway pantograph according to the present invention includes a boat body that contacts an overhead line, an upper frame that supports the boat body, and a lower frame that is attached to the roof side of an electric railway vehicle. A low-noise hinge cover device for a high-speed railway pantograph having a single arm structure, wherein a hollow portion of a hinge cover that covers a hinge portion connecting the upper frame and the lower frame is filled with an elastic material , and A horizontal groove is formed on the side surface of the hinge cover.

  In the present invention, focusing on the hinge portion of the pantograph device for high-speed railways, particularly in the low noise performance, experiments on acoustic characteristics were conducted to obtain the superiority of the present invention. In the prior art, the shape of the hinge serves as a noise generation source, and sounds due to standing waves and sounds due to irregular vortices are generated. In the present invention, however, both standing waves and vortices are suppressed. We propose a shape that can be used simultaneously.

That is, by filling the cavity of the hinge cover with an elastic material , the cavity is eliminated, and the generation of sound due to standing waves inside the hinge cover and the generation of sound due to irregular vortices are suppressed.

According to the present invention, the hollow portion of the hinge cover of the pantograph device is filled with an elastic material , and the horizontal groove is provided on the side surface of the hinge cover, thereby suppressing the occurrence of standing waves and reducing aerodynamic noise. In addition, the generated vortex can be collapsed to reduce the pressure fluctuation of the air pressure.

Hereinafter, embodiments of the present invention will be specifically described based on examples shown in the drawings.
2A and 2B are explanatory diagrams showing the principle of generation of aerodynamic noise by the hinge cover having a conventional configuration when the vehicle travels in the anti-sway direction, where FIG. 2A is a perspective view and FIG. 2B is a transverse cross-sectional view.

As shown in FIG. 2 (a), the hinge cover 4 having a conventional configuration covering the hinge portion that connects the upper frame 2 and the lower frame 3 includes a substantially triangular side wall plate 4a and upper and lower connecting portions 4b. The anti-swing direction is open and the inside is a cavity. In such a structure, as shown in FIG. 2B, the resonance (L = λ / 4, 3λ / 4,...) In the air column of the length L of the hinge cover 4 and the outer wall of the hinge cover 4 There is noise generation based on pressure fluctuations due to vortices generated in the section.
In order to suppress the generation of noise due to this resonance and vortex, the structure shown in FIGS. 3 and 4 was considered.

Figure 3 is a perspective view showing a grooved cavity without hinge cover 10 according to the actual施例of the present invention, FIG. 4 is a perspective view of a V-type hinge cover 11 according to a reference example.
In FIG. 3, the grooveless hollow hinge cover 10 according to the embodiment of the present invention is provided with a groove 10 a along the horizontal direction on the outer periphery of the side wall plate to fill the internal cavity. The material of the hinge cover 10 is preferably made of, for example, FRP in consideration of strength, weather resistance, and the like. In the experiment, the hinge cover 10 was manufactured using wood, and the experiment was performed with a plate thickness of 5 mm, a thickness D = 38 mm, and a length L = 70 mm (about 1/2 of the actual scale).

As a method of covering the cavity from the outside , as in the reference example shown in FIG. 5, a rubber plate 12 that covers the opening of the cavity of the hinge cover 10 is provided, and the lower frame 3 from the air cylinder built in the pantograph device. It is possible to pipe the air passage 13 provided in the interior and send air into the cavity, in which case the rubber plate 12 swells like a balloon, but the cavity remains in the interior. Therefore, as an embodiment of the present invention, as shown in FIG. 6, the hollow portion of the hinge cover 10 is filled with a stretchable material 14 such as silicon rubber in advance to prevent the link operation even when folded. Make the structure not to be.
In the experiment example, the groove 10a formed on the outer periphery of the side wall plate of the hinge cover 10 has a groove width of 5 mm, an interval of 10 mm, and a height of 3 mm.

The reason why noise is reduced by providing the groove 10a will be described.
FIG. 7 is an explanatory view showing Reason 1 for noise reduction. When a rectangular parallelepiped having a width D shown in FIG. 7A is placed in the air flow, the vortex is released to generate the vortex. The correlation length, which is an index indicating the degree of two-dimensionality, is required to be 3 to 6 times D. Therefore, as shown in FIG. 7B, if the grooves along the air flow direction are formed at intervals smaller than 3D to 6D, the correlation length is shortened and two-dimensional vortex shedding can be suppressed. , Noise can be reduced.

  FIG. 8 is an explanatory diagram showing Reason 2 for noise reduction. Since the velocity components of the air flowing along each of the upper frame 2 and the lower frame 3 are different, irregular vortices are emitted due to the velocity difference. Therefore, by providing the groove 10a along the air flow direction, the vortex breaks down, so that noise can be reduced.

In FIG. 4 showing a reference example , a V-shaped hinge cover 11 is attached to the hinge portions of the upper frame 2 and the lower frame 3. That is, the side wall is removed so that no cavity is formed inside. The reason why the V-shaped hinge cover 11 can suppress noise is simply that there is no cavity inside the hinge cover 11 and resonance does not occur. The material of the hinge cover 11 is preferably made of, for example, FRP in consideration of strength, weather resistance, and the like.

Experimental example

  The experiment was conducted using a low-noise wind tunnel and a wooden model. A schematic diagram of the experimental apparatus is shown in FIGS. The flow is a circulating type, and the measuring part is installed in an anechoic chamber and is semi-open. In the figure, 20 is a semicircular sound collector, 21 and 22 are microphones, 23 is a nozzle, 24 is an acoustically transparent end plate, 25 is an FFT (Fast Fourier Transform) analyzer, and 26 is a personal computer for analysis.

  In order to eliminate interference between the jet edge and the hinge cover model M, the opening of the outlet of the nozzle 23 is 180 mm × 360 mm and the length is 1200 mm. A sound-transmitting end plate 24 in which 8 mm in diameter) was combined as a reinforcing material was used. The experiment was carried out with air as the working gas and a main flow speed of 30 m / s. As shown in FIGS. 9 and 10, the hinge portion is fixed at a position 480 mm downstream of the nozzle, and noise is measured at the microphones 21 and 22 at the upper surface position (90 ° position) and the side surface position (0 ° position) while circulating the flow. Then, FFT (Fast Fourier Transform) analysis was performed. In order to approximate the sound pressure level to the auditory frequency characteristic, the A characteristic was weighted.

  FIG. 11 shows a schematic diagram of a model used in the experiment. The acoustic characteristics of the generated noise were obtained using a simplified model (FIG. 11A) from which the elements of the hinge portion were extracted. Thereafter, in order to identify the cause of the generated noise, a noise measurement experiment was performed using an inclined two-cylinder model (not shown) in which two cylinders were combined and a model in which the cavity portion was filled (FIG. 11B). From these results, an improved model considered to be effective for noise reduction, a grooved cavity-free model (FIG. 11 (c)) and a V-type hinge cover model (FIG. 11 (d)) were created, and a noise measurement experiment was conducted. .

Experimental Results and Discussion (1) Acoustic Characteristics of Generated Noise FIG. 12 shows the fluttering direction and anti-fluttering direction of the simplified model (FIG. 11 (a)) at the upper surface position (90 ° position) and the side surface position (0 ° position). And a sound pressure spectrum of background noise (BGN) which is a noise level when a flow is made to flow without a model installed. The vertical axis represents the A characteristic sound pressure level [dB (A)], and the horizontal axis represents the frequency [Hz].
From these results, a wind tunnel experiment using a simple model showed that the anti-fluttering direction had higher noise than the fluttering direction. The generated noise has directivity, and it has been found that there are a large peak at 1887 [Hz] in the 90 ° direction and a large number of peak rows in the 0 ° direction.

(2) Causes of noise generation Fig. 13 shows the simplified model, the tilted two-cylinder model, the model with the cavity part filled, and the sound pressure of the background noise at the top surface position (90 ° position) and side surface position (0 ° position). The spectrum is shown. From these results, it was found that the inclined 2-cylinder hardly generates noise. A large number of peak lines generated in the 0 ° direction exist regardless of the presence or absence of cavities. From this, it is considered that the flow separated at the front edge of the hinge cover generated irregular vortices, resulting in a large number of peaks. The peak generated in the 90 ° direction is 1887 [Hz], and a quarter length of the sound wavelength coincides with the depth of the cavity. Therefore, the difference in the peak sound pressure level depending on the presence or absence of the cavity is considered to be due to resonance in the cavity due to the flow separation at the front edge of the hinge cover as a sound source in the simple model.

(3) Improved model FIG. 14 shows a simplified model, a grooveless cavity model, a V-type hinge cover model, and a sound pressure spectrum of background noise at the top surface position (90 ° position) and the side surface position (0 ° position). Indicates. Table 1 shows a list of overall values for each model.
From these results, it was found that both the grooved cavityless model and the V-type hinge cover model had a noise reduction effect. It is thought that the sound pressure level of many peaks seen in the side direction could be reduced by suppressing the generation of vortices by providing a groove smaller than the vortex scale on the side of the hinge cover. Further, in the V-type hinge cover model, it is considered that noise was reduced by eliminating the cavity and suppressing the flow separation occurring at the hinge cover front edge.

From the above experiments, the following was found.
(1) From a noise measurement experiment using a simple model, it was found that the sound pressure level in the anti-swing direction is larger than the direction of the swing, and the generated noise has directivity.
(2) It was found that the peak sound in the 90 ° direction was caused by the presence or absence of a cavity, and the large number of peak sounds in the 0 ° direction were caused by flow separation occurring at the front edge of the hinge cover.
(3) It was found that noise can be reduced by taking measures.

  The present invention is a pantograph device that can suppress the occurrence of standing waves and reduce aerodynamic noise. In addition to a newly installed high-speed railway vehicle, the pantograph can be used to suppress pantograph noise in existing vehicles. It is possible to cope with higher speed of the vehicle.

It is a perspective view which shows an example of the pantograph for high-speed trains of a single arm structure. It is explanatory drawing which shows the generation | occurrence | production principle of the aerodynamic noise by the hinge cover of the conventional structure when a vehicle drive | works in the anti-swing direction, (a) is a perspective view, (b) is a cross-sectional view. It is a perspective view which shows the grooved hollow no hinge cover which concerns on the Example of this invention. It is a perspective view which shows the V-type hinge cover which concerns on a reference example. It is explanatory drawing which shows the reference example of the method of covering a cavity part from the outside . It is explanatory drawing which shows the example of the method of filling a cavity part in the Example of this invention. It is explanatory drawing which shows the reason 1 of noise reduction in the Example of this invention. It is explanatory drawing which shows the reason 2 of noise reduction in the Example of this invention. It is a sectional side view showing an experimental device. It is a front view which shows an experimental apparatus. (A)-(d) is a perspective view which shows the schematic of the model used in experiment. It is a graph which shows the sound pressure spectrum of the background noise which is a noise level at the time of flowing a flow in the state where the fluttering direction and the anti-fluttering direction of the simplified model and the model are not installed. It is a graph which shows the sound pressure spectrum of a simple model, an inclined 2 cylinder model, a model which filled the cavity part, and background noise. It is a graph which shows the sound pressure spectrum of a simple model, a grooveless cavity model, a V-type hinge cover model, and background noise.

DESCRIPTION OF SYMBOLS 1 Ship body 2 Upper frame 3 Lower frame 4 Hinge cover 5 Protective cover 6 Overhead wire 10 Non-cavity hinge cover 10a Groove 11 V-type hinge cover 12 Rubber plate 13 Air passage 14 Stretch material 20 Semicircular sound collectors 21 and 22 Microphone 23 Nozzle 24 Sound transmitting end plate 25 FFT analyzer 26 PC for analysis

Claims (1)

A low-noise hinge cover device for a high-speed railway pantograph having a single-arm structure having a boat body in contact with an overhead line, an upper frame supporting the boat body, and a lower frame attached to the roof side of an electric railway vehicle, A high-speed railway pantograph characterized in that a hollow portion of a hinge cover that covers a hinge portion connecting the upper frame and the lower frame is filled with a stretchable material , and a horizontal groove is formed on a side surface of the hinge cover. Low noise hinge cover device.

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