JPH09331203A - System for preventing snow accretion onto antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an antenna from being coated with snow even when the inclined angle of the antenna against the ground surface is low and the snow is wet by applying vibrations to the antenna in a fixed direction between the direction perpendicular to the surface of the snow accretion and a snow carrying direction in which the snow is moved on the surface of the snow accretion. SOLUTION: A plate spring 13 fitted to a plane 11 parallel to a radome 12 is inclined by an angle θ and a steel piece 21 attached to the spring 13 is opposed to an electromagnet 14. When the electromagnet 14 is energized, the piece 21 is attracted to the electromagnet 14 and the spring 13 and the radome 12 fixed to the spring 13 move in a direction V(+) which is deflected from the surface of the radome 12 by an angle α(≈θ). When the current supplied to the electromagnet 14 is broken, the attracting force of the electromagnet 14 disappears and the radome 12 is moved in the direction V(-) by the elasticity of the spring 13. When the current supply to the electromagnet 14 is repeatedly turned on an off, the radome 12 vibrates in the directions V(+) and V(-). Since the vibrating direction has a vertical component, the frictional force between a snow piece 22 adhering to the radome 12 and the surface of the radome 12 decreases and, as a result, the snow piece 22 moves in the snow carrying direction when acceleration is applied to the snow piece 22 in the direction V(-).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna, and more particularly to a snow accretion prevention system for an antenna having a planar spread.

[0002]

2. Description of the Related Art Conventionally, in a snow accretion preventing system for an antenna having a two-dimensional spread, even when utilizing mechanical vibration, consideration is not given to controlling the vibration direction, and vibration is applied. The aim was to simply shake off the snow or help it slide off under its own weight.

[0003]

As the angle of the antenna increases and the inclination of the antenna reflector with respect to the ground decreases, especially in the case of satellite communication, it is difficult to use gravity, and wet snow is used. In the case of, it becomes especially difficult.

An object of the present invention is to provide a snow accretion prevention system which can sufficiently exhibit the effect even when the antenna reflector has a gentle inclination or when the snow is wet.

[0005]

According to the snow accretion prevention system for an antenna of the present invention, the snow accretion surface to be covered with snow is moved in a direction perpendicular to the snow accretion surface and on the snow accretion surface. It has a snow landing surface vibrating means for vibrating in a certain direction in the middle of the snow landing transport direction to be made, and the snow on the snow landing surface is provided in a direction perpendicular to the snow landing plane and in a snow landing transport direction. The acting force is applied intermittently and continuously.

The above-mentioned snow surface vibration means directly touches the snow surface,
Alternatively, it is indirectly vibrated via a snow surface support structure.

When the snow landing surface is a radome attached to the parabolic reflector, the snow landing surface vibrating means may drive the snow landing surface via the radome supporting structure for the parabolic reflector.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a conceptual diagram showing an example of a parabolic antenna provided with the snow accretion preventing system of the present invention, and FIG. 2 is an explanatory view of snow accretion preventing operation in the parabolic antenna of FIG.

In FIG. 1, a flat radome 12 is attached to the front surface of the parabolic reflector 11 with respect to the feed horn 10. To support the radome 12, an iron piece inclined by a certain angle from the antenna pointing direction is provided. The leaf spring 13 is used, and when the electromagnet 14 is energized, the leaf spring 13 vibrates.
Vibrates in a certain direction.

Next, the operation of preventing snow accretion on the radome 12 in the parabolic antenna of FIG. 1 will be described in detail with reference to FIG.

In FIG. 2 (a), a plane 11 (that is, radome 1) perpendicular to the antenna pointing direction of the parabolic reflector is shown.
The leaf spring 13 attached to the plane parallel to 2) is inclined by an angle θ from the direction of the antenna orientation.
The iron piece 21 attached to 3 faces the electromagnet 14.

The carrying direction is the direction on the surface of the radome 12 on which the snowflakes 22 on the radome 12 are to be moved (not necessarily the maximum tilt direction), and the iron piece 21 and the electromagnet 1 are used.
4 corresponds to the opposite direction.

When the electromagnet 14 is energized, the iron piece 21 is attracted, and as a result, the leaf spring 13 and further the radome 12 move. As for the moving direction, since the angle of θ is provided for the attachment of the leaf spring 13, the angle V (α) is formed from the surface of the radome 12 on a plane perpendicular to the surface of the radome 12 and parallel to the transport direction. +) Direction. That is,
The V (+) direction is midway between the transport direction on the radome surface and the direction perpendicular to the radome surface, and α is approximately equal to θ. Then, when the electric current of the electromagnet 14 is cut off, the attractive force is lost, and the elasticity of the leaf spring 13 causes the radome 12 to move to V (−).
Move in the direction. If the above operation is repeated continuously, the radome 12 vibrates in the V (+) direction and the V (-) direction. At this time, the efficiency can be improved by matching the ON / OFF cycle of the electromagnet with the resonance frequency of the vibration system including the radome 12 and the leaf spring 13.

2 (b) and 2 (c) show the effect of the above-mentioned vibration on the snow flakes 22 on the radome 12.

When the acceleration 31 is applied in the V (+) direction due to the vibration as described above, the snowflakes 2 attached to the radome 12
An inertial force 32 is generated in 2 as a reaction thereof. This inertial force 32 is a horizontal component 33 that is horizontal to the radome 12.
And a vertical vertical component 34. in this way,
Due to the presence of the vertical component 34, the snowflakes 22 are pressed against the radome 12, and the frictional force is increased to suppress the sliding in the direction of the horizontal component 33.

On the other hand, when an acceleration 35 is applied in the V (-) direction, an inertial force 36 composed of a horizontal component 37 and a vertical component 38 is generated on the snowflakes 22. Since the vertical component 38 is away from the radome 12, the frictional force is reduced, and the horizontal component 37 slips.

As a result, the snowflakes 22 move in the horizontal component 37 direction, that is, in the carrying direction.

[0019]

[Effects of the Invention] Even when the parabona antenna has a slight inclination with respect to the ground surface or when the snow is wet, by deciding the direction so as to exert a force for effectively transporting snow on the radome and applying vibration. There is an effect that can prevent snow accretion sufficiently.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing an example of a parabona antenna provided with a snow accretion prevention system of the present invention.

FIG. 2 is a diagram for explaining the operation of the snow accretion prevention system of the present invention.

[Explanation of symbols]

 10 feeding horn 11 parabolic reflector 12 radome 13 leaf spring 14 electromagnet 21 iron piece 22 snowflake 31 acceleration 32 inertial force 33 horizontal component 34 vertical component 35 acceleration 36 inertial force 37 horizontal component 38 vertical component

Claims (3)

[Claims] 1. In a snow accretion prevention system for an antenna having a planar spread, a snow accretion surface to be covered with snow is moved in a direction perpendicular to the snow accretion surface and on the snow accretion surface. And a snow landing surface vibrating means for vibrating the snow landing surface in a certain direction midway between the snow landing direction and the snow landing direction. A snow accretion prevention system for an antenna, characterized by intermittently and continuously applying a force acting on the direction. 2. The snow accretion prevention system for an antenna according to claim 1, wherein the snow accretion surface vibrating means vibrates the snow accretion surface directly or indirectly through the snow accretion surface support structure. 3. The snow landing surface is a radome attached to a parabolic reflector, and the snow landing surface vibrating means drives the snow landing surface via a support structure of the radome with respect to the parabolic reflector. Item 2. A snow accumulation prevention system for an antenna according to Item 2.