JPH10261908A - Snow melting device for parabolic antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive snow melting device that saves energy and melts snow efficiently. SOLUTION: This device is provided with a thermal insulator 3 adhered to a parabolic antenna 1, a heater 5 made of copper, aluminum, nickel, copper alloy, aluminum alloy or nickel alloy foil that is adhered on the insulator 3 and a surface protection material 6 adhered on the heater. Heat generated in the heater 5 melts snow adhered on the parabolic antenna 1. The calorific value per a unit area of a lower part of the heater 5 is more than 1.5 times of a calorific value per a unit area of an upper part of the heater 5 or the heater 5 may be constituted by the lower part only. Furthermore, a thermostat is adhered to a position of the lower part where snow is easy to be left and the thermostat is inserted in series between a power supply and the heater 5. The heater 5 is energized when snow is adhered on the parabolic antenna 1 and temperature decreases and when the snow adhered on the parabolic antenna 1 melts and the temperature rises, the emerging is interrupted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a snow melting device provided on a reflector of a parabolic antenna or an offset parabolic antenna.
In particular, the present invention relates to a snow melting apparatus including a thermostat and having different heating values in upper and lower portions.

[0002]

2. Description of the Related Art Snow adheres to a parabolic antenna and hinders its function as a parabolic antenna. Most of the snow has a gentle slope under the reflector of the parabolic antenna,
The snow that hit the reflector is attached so that it can be collected, and once attached, it is difficult to melt. Melting snow once attached requires a lot of energy, and a little energy requires a long time. In addition, the partially melted water may freeze and damage the surface of the reflector.
In particular, when used in an area with a lot of snowfall, a snow melting device for melting snow attached to the parabolic antenna is indispensable.

[0003] There has been a need for a device that can effectively melt snow attached to a parabolic antenna.

Conventionally, in order to melt snow attached to a parabolic antenna, the reflecting mirror is heated by a snow melting apparatus in which a heating element is directly attached to the back surface of the reflecting mirror. However, the wind hits both the back and front surfaces of the reflector, and the heat escapes, so that the thermal efficiency of the snow melting device is reduced by half.

According to Japanese Patent Application Laid-Open No. 3-267802,
He pointed out the problem of installing a heating element on the back of the reflector of the parabolic antenna and offset parabolic antenna as a snow melting device, and applying snow-resistant paint to the surface of the reflector.
As an efficient and inexpensive snow melting device, a heating element is provided at a part of the outer edge of the reflecting mirror.

According to Japanese Patent Application Laid-Open No. 2-174401,
It points out the problems of providing a heating element on the back side of the reflector (reflecting mirror), using hot water circulation, and providing a heating element between the reflector and the backup layer or in the backup layer as a snow melting device. In addition, a linear heating element is provided in contact with the reflector in the protective member on the outer edge of the reflector.

JP-A-2-44803 and JP-A-2-44803
According to -44804, a first layer having low thermal conductivity, a heating element made of nichrome wire or carbon powder, and a second layer of a member having a small friction coefficient are arranged on the surface of the reflecting mirror. . In addition, the interval between the heating elements made of nichrome wire or carbon powder is arranged to be narrower in a lower portion where snow tends to adhere.

[0008]

FIG. 2 is a partially broken perspective view of a conventional parabolic antenna in which a heating element is attached to the back surface of a reflecting mirror.

In a snow melting apparatus in which the heating element 5 is attached to the back surface of the metal reflecting mirror 2 and the surface of the reflecting mirror 2 is heated by heat conduction, the heat generated by the heating element 5 is dispersed between the reflecting mirror and the back surface.
Not effective. In addition, both the heating element 5 attached to the back surface of the reflecting mirror 2 and the surface of the reflecting mirror 2 are cooled by the wind, so that the thermal efficiency is further reduced.

When the reflecting mirror 2 is made of a resin, it is not suitable because the thermal conductivity of the resin is low. Further, the back surface is not suitable because it requires structural reinforcing ribs.

[0011] Further, the heating element 5 cannot be uniformly attached to the back surface of the reflecting mirror 2 of both metal and resin because the back surface of the reflecting mirror 2 has a mount for adjusting and fixing the direction of the parabolic antenna 1. However, there is a problem that the snow melting apparatus is not suitable.

To solve these problems, the following snow melting apparatus has been proposed.

In Japanese Unexamined Patent Publication No. Hei 3-267802, in a snow melting device of a heating element attached to an outer edge, heat conduction is used between a portion to be heated and a portion to generate heat, and heat is efficiently released by wind. There was a problem that was not.

In Japanese Unexamined Patent Publication No. Hei 2-174401, in a snow melting apparatus in which a heating element is disposed in a protective member at an outer edge, the heating element is not cooled by wind, but utilizes heat conduction to release heat by wind. There was a problem that it was not effective.

JP-A-2-44803 and JP-A-2-44803
No. 44804 discloses a snow melting apparatus that effectively melts snow by attaching a thread-like heating wire made of nichrome wire or carbon powder to a main reflecting mirror densely at a lower portion and sparsely at an upper portion. ing. However, thickly covering the main reflecting mirror surface leads to deterioration of the characteristics of the main reflecting mirror. In order to make the snow melting apparatus thinner, a thin nichrome wire or a heating wire is required, and in order to obtain a required heating value, the total length is increased, and material costs and processing costs are increased. there were.

In view of the above problems, it is an object of the present invention to provide a low-cost snow melting device for a parabolic antenna that efficiently melts snow while saving energy.

[0017]

In a snow melting apparatus for a parabolic antenna, a heat insulating material provided on a surface of a reflecting mirror of the parabolic antenna which reflects radio waves, and copper, aluminum, nickel provided on the heat insulating material are provided. , A heating element made of a foil of a copper alloy, an aluminum alloy or a nickel alloy, and a surface protection material provided on the heating element. The heat generated by the heating element melts snow attached to the parabolic antenna.

The calorific value per unit area of the lower part of the heating element (the part to which snow easily adheres) is at least 1.5 times the calorific value per unit area of the upper part of the heating element (the upper part of the lower part). It is preferred that The heating element may be constituted only by the lower part.

Further, a thermostat is provided at a position where snow tends to remain under the reflector above the heat insulating material, and the thermostat is inserted in series between a power source and the heating element. The heating element is energized when snow adheres to the parabola antenna and the temperature decreases, and the energization is interrupted when the snow adhering to the parabola antenna melts and the temperature rises.

Further, it is preferable that the snow melting device for a parabolic antenna is made to be an attachment type so that it can be easily attached at home.

[0021]

FIG. 1 is a partially cutaway perspective view of a snow melting apparatus for a parabolic antenna according to the present invention.

The back surface of the heating element 5 is made of a heat insulating material 3 and does not transmit heat to the reflecting mirror 2, so that even if the back surface of the reflecting mirror 2 is cooled by wind, heat dissipation is small.

The thicker the sheet-like heat insulating material 3, the better the heat retention. However, the radio wave reflected on the surface of the reflecting mirror 2 and the radio wave reflected on the surface of the heating element 5 have a phase difference, and the phase difference depends on the thickness of the heat insulating material 3 and the heating element 5. When the thickness of the layer is large, the radio wave reflection characteristics deteriorate. In consideration of both, the thickness of the heat insulating material 3 is preferably 0.5 mm to 1.5 mm.

The material of the heat insulating material may be any known material.
The heating element 5 is a foil of copper, aluminum, nickel, a copper alloy, an aluminum alloy or a nickel alloy and has a thickness of 0.1.
mm. The surface protection material 6 may be a sheet of vinyl chloride having excellent heat resistance, cold resistance and weather resistance, or any of known materials. The surface protection material 6 protects the surface of the heating element and enables long-term outdoor use.

FIG. 3 is a perspective view showing a state of snow attached to the parabolic antenna. FIG. 4 is a circuit diagram of a snow melting device for a parabolic antenna.

The snow 8 easily adheres to the lower part of the reflecting mirror 2,
Also easy to remain.

The heating element 5 includes an upper surface heater 18a.
And the lower surface heater 18b and the thermostat 14
It consists of.

The calorific value per unit area of the lower surface heater 18b is at least 1.5 times the calorific value per unit area of the upper surface heater 18a. 14 is attached.
Since the calorific value is determined by the shape of the foil of copper, aluminum, nickel, a copper alloy, an aluminum alloy or a nickel alloy, the surface heater 18b whose width is reduced to half or less of the surface heater 18a has a calorific value of 2 or less. More than double.

The terminal of the thermostat 14 is connected to the surface heater 1
8b, and the thermostat 14 may be attached to a heat insulating material with an insulating double-sided adhesive.

The thermostat 14 is inserted in series between the power source and the surface heaters 18a and 18b. The temperature of the thermostat 14 is reduced by the snow 8 attached to the parabolic antenna 1, and the thermostat 14 operates, and the surface heaters 18 a and 1.
8b is energized. Due to the heat generated by the surface heaters 18a and 18b, the upper part melts first because there is little snow. Then, when the snow 8 attached to the lower part melts, the temperature rises and the energization is cut off. Therefore, the surface heaters 18a and 18b can be energized and all the snow 8 can be melted until the snow 8 at a position that is likely to remain melts.

The surface heaters 18a and 18b are foils of copper, aluminum, nickel, a copper alloy, an aluminum alloy or a nickel alloy and have a thickness of about 0.1 mm. The width, length, shape, and gap between the heating elements may be determined according to the required total heating capacity. The operating temperature of the thermostat 14,
The optimal cut-off temperature is selected according to the shape, size, and material of the parabolic antenna, heat insulating material, and surface protective material.

Although the thermostat 14 operates even at a low temperature, it is preferable to activate the snow melting apparatus by preparing a power supply only when snow falls. Also, by adding a snow sensor to the circuit in series with the thermostat 14, the trouble of turning on and off the power supply is eliminated. Any known device may be used for the snow sensor.

FIG. 5 shows another embodiment of the present invention. In this embodiment, a surface heater 18 is provided below the reflector.
To make a snow melting device. In this case, when the snow in the lower part melts, the snow in the upper part without the heating element falls at once by its own weight or is melted in the lower part. If the snow melting device is constituted only by the lower portion, a lower cost snow melting device can be obtained.

The power supply is stepped down from a household voltage of AC 100 V by a transformer to a low voltage of AC 30 V or less. The lower the voltage, the higher the energizing current. To suppress the voltage drop in the line, there is a problem that the connecting wire becomes thicker and the transformer is required. However, since the parabolic antenna is used outdoors, the snow-melting device may be exposed to rain and cause an electric shock accident. However, adopting a low voltage eliminates danger and facilitates wiring work.

The wiring from the power source is once received at the terminal,
It is preferable to control the NB heater simultaneously. The terminal is preferably fixed to the vicinity of the thermostat or the back surface of the reflector with an insulating double-sided adhesive.

If the shape of the heating element 5 is a flat surface having a cut, when the heating element 5 is attached to a reflecting mirror of a parabolic antenna having a hyperboloid of revolution, it can be attached without overlapping and wrinkling. In addition, copper, aluminum,
When the surface is covered by reciprocating a short line in consideration of expansion and contraction of nickel, copper alloy, aluminum alloy or nickel alloy due to heat, disconnection and separation from the reflection surface do not occur.

[0037]

The snow melting apparatus according to the present invention has a structure in which most of the heat is generated for melting the snow, thereby saving energy. In addition, by arranging a thermostat for controlling the energization of the snow melting device in the lower part where snow tends to remain, the energization is performed until the attached snow melts, and thereafter the energization is automatically cut off, so that the efficiency is high. In addition, since the foil of copper, aluminum, nickel, copper alloy, aluminum alloy, or nickel alloy is processed into a shape that can obtain the required heat value and used as the surface heater of the heating element, a low-cost snow melting device for a parabolic antenna is used. Becomes

[Brief description of the drawings]

FIG. 1 is a partially broken perspective view of a snow melting device for a parabolic antenna according to the present invention.

FIG. 2 is a partially broken perspective view of a conventional snow melting device for a parabolic antenna.

FIG. 3 is a perspective view of a state of snow attached to a parabolic antenna.

FIG. 4 is a circuit diagram of a snow melting device for a parabolic antenna.

FIG. 5 is a circuit diagram of a snow melting device for a parabolic antenna.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Parabolic antenna 2 Reflector 3 Heat insulating material 5 Heating element 6 Surface protection material 8 Snow 10 Mount 11 Feed horn 12 Converter support arm 13 Converter 14 Thermostat 18 Surface heater

Claims (9)

[Claims] 1. A heat insulating material, a foil-shaped heating element on the heat insulating material, and a surface protection material on the heating element are provided on a surface of the reflecting mirror of the parabolic antenna on the side of reflecting a radio wave, A snow melting apparatus for a parabolic antenna, wherein the heat generated by the heating element melts the snow attached to the parabolic antenna. 2. The snow melting device for a parabolic antenna according to claim 1, wherein the heating element is made of copper, aluminum, nickel, a copper alloy, an aluminum alloy, or a nickel alloy foil. 3. The heating element is installed on the entire surface of the reflecting mirror of the parabolic antenna on the side of reflecting the radio wave, and the heating value per unit area of the lower part is equal to the heating value per unit area of the upper part. The snow melting device for a parabolic antenna according to claim 1, wherein the snow melting device is 1.5 times or more. 4. The parabolic antenna according to claim 1, wherein the heating element is provided partially on a surface of the reflector of the parabolic antenna on the side of reflecting a radio wave, and heats a lower portion of the reflector. A snow melting device for a parabolic antenna according to claim 1. 5. The heating element is provided on the entire surface of the reflecting mirror of the parabolic antenna on the side of reflecting the radio wave, and the amount of heat generated per unit area is increased stepwise or downward from the upper end to the lower end of the reflecting mirror. 3. The snow melting device for a parabolic antenna according to claim 1, wherein the snow melting device increases continuously. 6. The heating element includes a thermostat, the thermostat being located below the reflector above the insulation,
The thermostat is provided at a position where snow tends to remain, and the thermostat is inserted in series between the power supply and the heating element. The snow melting device for a parabolic antenna according to any one of claims 1 to 5, wherein the energization is interrupted by increasing the melting temperature of the attached snow. 7. The heat insulating material having a thickness of 0.5 mm to 1.
The snow melting device for a parabolic antenna according to any one of claims 1 to 6, which is 5 mm. 8. A parabolic antenna snow melting device formed by combining the heat insulating material, the heating element, and the surface protective material together with the heat insulating material serving as an adhesive material, and attaching the snow melting device to the reflector of the parabolic antenna. 8. The method according to claim 1, wherein:
The snow melting device for a parabolic antenna according to any one of the above. 9. The heat insulating material, the heating element, and the surface protection material may be stuck on a parabolic antenna rotating hyperboloid without overlapping or wrinkling in a plane having a cut. The snow melting device for a parabolic antenna according to claim 1.