JP2002127899A - Low noise louver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce noise of a louver of an air conditioner for a conventional railway rolling stock, the outer frame of which is formed square and on the outer frame of which a plural number of fins are mounted to be orthogonal with an air current. SOLUTION: The fins provided on the louver are set in the air current direction by making an outer frame shape of the louver of a suction port or an exhaust port parallelogram on an air conditioning system for the railway rolling stock. Additionally, a deflecting surface of the fin provided on the outer frame of a bar is provided along the traveling direction. Additionally, this is the low noise louver making an interval between the fin and the fin 5 mm-30 mm and making roundness of an outer frame edge part of the louver 10 mm-50 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioning system for a railway vehicle, and more particularly to a low noise louver for reducing aerodynamic noise generated at a louver at an intake or an exhaust of a railway vehicle running at high speed.

[0002]

2. Description of the Related Art As a structure of a conventional air conditioner for a railway vehicle, for example, Japanese Patent Application Laid-Open No. 11-321644 discloses an air conditioner for a railway vehicle. According to this,
An exhaust port is provided on a side surface of the vehicle, and an intake port is provided on a roof surface of the vehicle body. A plurality of fins are mounted in the intake port so as to be orthogonal to the traveling direction of the vehicle. In addition, the rim of the intake port and the fins attached to the intake port and perpendicular to the traveling wind are both processed so as to have the same curvature as the vehicle body surface, and are attached to the intake port rim so as to have the same surface as the vehicle body roof surface Have been. In addition, the cross section of the inner periphery of the louver outer frame edge has a rounded shape.

[0003]

Consideration of noise is indispensable from the viewpoint of environmental preservation in railway vehicles running at high speeds, especially in the case of Shinkansen bullet trains. When the speed exceeds about 250 km / h, the rolling noise generated between the wheels and the rails is reduced. Aerodynamic noise is more prominent. The largest cause of aerodynamic noise is due to the vortex from the pantograph, but this problem is being reduced in noise by improving the shape. The next problem is aerodynamic noise generated when the louver of the air conditioner is exposed to high-speed airflow. This generates aerodynamic noise due to a vortex generated when the high-speed air stream collides with the downstream portion of the louver.

Therefore, Japanese Patent Application Laid-Open No. 11-321644 discloses an air conditioner for a railway vehicle capable of reducing noise. According to this, an exhaust port is provided on the side of the vehicle, and an intake port is provided on the roof surface of the vehicle body, and a plurality of fins are mounted in the intake port so as to be orthogonal to the vehicle traveling direction. I have. The edge of the intake port and the fins attached to the intake port and orthogonal to the traveling wind,
Both are machined so as to have the same curvature as the vehicle body surface, and are attached to the edge of the intake port so as to have the same surface as the vehicle body roof surface. In addition, the end section of the inner periphery of the louver outer frame edge has a rounded shape.

However, when the aerodynamic noise from the louver was examined for the relationship between the positional relationship between the airflow direction and the direction of the fins provided on the louver and the aerodynamic noise level, it was found that the configuration disclosed in Japanese Patent Application Laid-Open No. 11-321644 reduced noise. Is difficult, and the result is that the noise level can be reduced by installing the fins provided on the louvers in the airflow direction. SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a low-noise louver that reduces aerodynamic noise generated from a louver.

[0006]

In order to achieve the above object, according to the present invention, in the air conditioning system for railway vehicles, the aerodynamic noise is proportional to the sixth power of the flow velocity (sixth power law). The shape of the outer frame of the louver of the intake port or the exhaust port is a parallelogram, and the flow velocity in the direction perpendicular to the outer frame is reduced to reduce aerodynamic noise.

Further, since the noise level can be reduced by installing the fins provided on the louvers in the direction of the air flow, the deflection surfaces of the fins provided on the outer frame of the louvers at the intake or exhaust ports extend along the running direction. Low noise louvers are provided.

Further, since the aerodynamic noise can be reduced by reducing the distance between the fins and smoothing the flow, the distance between the fins provided on the outer frame of the louver of the intake port or the exhaust port can be reduced. 5 mm to 30 mm. Furthermore, by making the edge of the outer frame of the louver round, the flow can be smoothed and aerodynamic noise can be reduced, so that the cross-sectional shape of the inner peripheral edge of the outer frame of the louver at the intake or exhaust port is: The low noise louver has a roundness of 10 mm to 50 mm.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments, and can be implemented with appropriate modifications.

FIG. 1 shows a low-noise louver according to a first embodiment of the present invention. FIG. 1A is a perspective view showing a louver installed on a vehicle body roof, and FIG. It is a perspective view showing an object. FIG. 2 is a sectional view of only the low-noise louver along the line AA in FIG. In FIG. 1, an outer frame 2 of the low noise louver 1 is formed in a parallelogram shape, and a plurality of fins 3 are mounted in the inside surrounded by the outer frame 2 along a flow direction. Although the fins 3 are mounted parallel to the flow direction, they may be mounted at a slight angle. Further, as shown in FIG. 2, the inner edge 4 of the outer frame 2 which is orthogonal to the flow direction is rounded.

FIG. 3 is a plan view of a low-noise louver showing another embodiment. In FIG.
Is formed to 5 mm to 30 mm. When a noise grasping experiment was performed using a low-noise wind tunnel, it was confirmed that the noise decreased as the interval X between the fins 3 was reduced. If the interval X is less than 5 mm, the air intake / exhaust efficiency decreases, and if the interval X exceeds 30 mm, the same level of noise as the conventional louver is generated.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to confirm the effect of the low noise louver 1 according to the present invention, a low noise louver 1 and a conventional louver were installed using a low noise wind tunnel so that the louver surface was exposed to an air flow, and the noise level was reduced. The overall value was measured.

FIG. 4 shows the relationship between the inclination angle of the outer frame 2 of the louver and the noise level. In the figure, the vertical axis is the overall noise level dB (A), and the horizontal axis is the wind speed m / s. In the figure, a shows a conventional rectangular louver, b shows a 60 ° parallelogram louver, and c shows a 45 ° parallelogram louver, and the noise level increases as the wind speed increases. However, as the inclination of the outer frame 2 of the louver is increased, the noise level decreases, and the noise level decreases.
When it was tilted, a noise reduction effect of 4 dB was obtained as compared with the conventional rectangular louver. This is because when the airflow collides with the outer frame 2 on the downstream side of the louver, the flow velocity in the direction perpendicular to the outer frame 2 is reduced, and aerodynamic noise is reduced. The noise reduction effect refers to a reduction amount of the overall noise level dB (A) as compared with a conventional rectangular louver.

FIG. 5 shows the relationship between the fin spacing and the noise level. In the figure, the vertical axis represents the overall noise level dB (A), and the horizontal axis represents the wind speed m / s.
It is. In the figure, a shows a parallelogram louver with a fin interval of 50 mm, b shows a fin interval of 30 mm, and c shows a fin interval of 15 mm, and the noise level increases as the wind speed increases. As shown in the figure, it was confirmed that the noise level was reduced as the interval X between the fins 3 was reduced. Although not shown, the interval X between the fins 3 is 5 mm.
At ~ 30 mm, a remarkable noise reduction effect was obtained. This is because the smaller the distance X between the fins 3, the smaller the turbulence of the flow. If the interval X is less than 5 mm, the air intake / exhaust efficiency is reduced, and if the interval X is more than 30 mm, the same noise as a conventional bar is generated.

FIG. 6 shows the relationship between the roundness of the inner edge of the outer frame and the noise level. In the figure, the vertical axis is the overall noise level dB (A), and the horizontal axis is the wind speed m / s. In the figure, a is a right-angled edge, b is a radius 1
0 mm edge, c indicates a 20 mm radius edge,
The noise level increases as the wind speed increases. As shown in the figure, it was confirmed that the noise level was reduced as the round shape of the outer frame inner edge 4 was increased. Although not shown, a remarkable noise reduction effect was obtained at 10 mm to 50 mm. This is because the larger the radius, the smoother the flow, and the generation of vortices is suppressed. If the radius is less than 10 mm, the same noise as the conventional louver is generated, and if it exceeds 50 mm, it is difficult to form the same due to the structure.

[0016]

Since the present invention is configured as described above, the following effects can be obtained. By changing the shape of the outer frame of the louver of the intake port or the exhaust port provided in the vehicle body from a conventional rectangle to a parallelogram, when the airflow collides with the outer frame on the downstream side of the louver, the outer frame in a direction perpendicular to the outer frame. Aerodynamic noise is reduced by reducing the flow velocity.

The distance X between the fins 3 is 5 mm to 30 m.
By setting m, the turbulence of the flow is reduced, so that the aerodynamic noise is reduced. Furthermore, since the radius of the inner edge of the louver outer frame is set to 10 mm to 50 mm, the flow becomes smooth, and as a result, the strength of the vortex is suppressed and aerodynamic noise is reduced.

[Brief description of the drawings]

1A and 1B show a low noise louver according to a first embodiment of the present invention, in which FIG. 1A is a perspective view showing a louver installed on a vehicle body roof, and FIG. FIG.

FIG. 2 is a cross-sectional view of only the low noise louver along the line AA in FIG.

FIG. 3 is a plan view of a low-noise louver showing another embodiment.

FIG. 4 is a diagram showing the relationship between the inclination angle of the outer frame of the louver and the noise level.

FIG. 5 is a diagram illustrating a relationship between a fin interval and a noise level.

FIG. 6 is a diagram showing the relationship between the size of the rounded shape of the inner edge of the outer frame and the noise level.

[Explanation of symbols]

 1,11 Low noise louver 2 Outer frame 3 Fin 4 Inner edge X interval

Claims (3)

[Claims] 1. An air conditioning system for a railway vehicle,
A low-noise louver characterized in that the outer frame shape of the louver of the intake port or the exhaust port is a parallelogram. 2. The low noise device according to claim 1, wherein the fins provided on the outer frame of the louver at the intake port or the exhaust port have deflecting surfaces provided along the traveling direction. louver. 3. An interval (X) between fins (3) provided on an outer frame (2) of a louver of an intake port or an exhaust port is 5 mm.
The low-noise louver according to claim 1 or 2, wherein the cross-sectional shape of the inner peripheral edge portion (4) of the louver has a roundness of 10 to 50 mm.