JPH112681A - Snowfall detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a snowfall detector wherein wiring for a temperature detection means can be simplified. SOLUTION: Rectifying elements 4, 6 regulating an energizing direction to only one direction are provided on one end side of each temperature sensor 3, 5 respectively so that the energization regulation direction of each temperature sensor 3, 5 is a mutually reverse direction. Since the detection signal of each temperature sensor 3, 5 is alternately detected, total two pieces of wiring need not be provided on each temperature sensor 3, 5 by alternately switching the polarity of voltage applied on each temperature sensor 3, 5 by a switching circuit 8a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a snowfall detecting device for a snowmelting device used on a road in a snowfall zone.

[0002]

2. Description of the Related Art Conventionally, as this type of snowfall detection device,
For example, as described in JP-A-7-151865, a snow plate having a pair of electrodes on the surface, a moisture detector that detects moisture attached to the snow plate with each electrode,
2. Description of the Related Art There is known an outdoor air temperature sensor that detects an outdoor air temperature, a snow plate temperature sensor that detects a temperature of a snow plate, and a heater that heats the snow plate. In this snowfall detection device, when it is detected that the temperature detected by the outside air temperature sensor becomes equal to or lower than the temperature at which snowfall is possible and the snow falls on the snow receiving plate and the respective electrodes are connected to each other by the moisture of the snow, a predetermined snowmelting device is used. Is activated. In addition, in order to melt the snow falling on the snow receiving plate as moisture for electrode conduction, the snow receiving plate is heated by a heater, and the temperature of the snow receiving plate is detected by a snow receiving plate temperature sensor. Is controlled so as to have a substantially constant temperature.

[0003]

The outside air temperature sensor and the snow plate temperature sensor each comprise a temperature detecting element such as a thermistor for detecting the temperature as an electric signal. It is connected. However, when wiring is performed for each of the outside air temperature sensor and the snow plate temperature sensor, there is a problem that the number of wirings increases, and problems such as an increase in cost and connection failure occur due to complicated wiring.

[0004] The present invention has been made in view of the above problems, and an object of the present invention is to provide a snowfall detection device capable of simplifying wiring to temperature detection means.

[0005]

In order to achieve the above object, according to the present invention, there is provided a snow plate for detecting moisture adhering to a surface, an outside air temperature detecting means for detecting an outside air temperature, and a receiving plate. A snow receiving plate temperature detecting means for detecting the temperature of the snow receiving plate, and a heating means for heating the snow receiving plate, and detects snowfall based on the moisture detection of the snow receiving plate and the detected temperature of the outside air temperature detecting means, In a snowfall detecting device which controls the heating means based on the temperature detected by the snow plate temperature detecting means, a temperature detecting element for detecting the temperature of each of the outside air temperature detecting means and the snow plate temperature detecting means as an electric signal. One end side and the other end side of each temperature detecting element are connected to the apparatus main body side by common wiring, respectively, and one end side of each temperature detecting element is regulated to restrict the energizing direction to only one direction. A means to energization restricting direction of the temperature detecting element is in opposite directions, and a switching means for switching the polarity of the voltage applied to each of the temperature detecting element alternately. Thus, by alternately switching the polarity of the voltage applied to each temperature sensor, the detection signal of each temperature sensor is alternately detected, so that it is not necessary to provide a plurality of wires for each temperature sensor.

According to a second aspect of the present invention, in the snowfall detecting device according to the first aspect, a temperature detecting element as a snow receiving plate temperature detecting means and a temperature detecting element as an outside air temperature detecting means are provided on a back surface of the snow receiving plate. And a rectifying element as rectifying means. Thus, in addition to the effect of the first aspect, since the temperature detecting elements and the rectifying elements are connected to the conductive pattern of the snow plate, there is no need for a separate board or the like for connecting these elements.

[0007]

1 to 4 show one embodiment of the present invention. FIG. 1 is a schematic configuration diagram of a snowfall detection device, FIG. 2 is an exploded perspective view of a main part thereof, and FIG. FIG. 4 is a perspective view showing the back surface of the board, and FIG.

The snowfall detecting device includes a snow plate 1 for detecting moisture attached to the surface, and a heater 2 for heating the snow plate 1.
A snow plate temperature sensor 3 for detecting the temperature of the snow plate 1;
A first rectifying element 4 for regulating the direction of current flow of the snow plate temperature sensor 3, an outside temperature sensor 5 for detecting the outside temperature, and a second rectifying element 6 for regulating the direction of current flow of the outside temperature sensor 5.
A moisture detecting circuit 7 for detecting that moisture has adhered to the snow receiving plate 1; a temperature detecting circuit 8 for detecting the temperatures of the snow receiving plate temperature sensor 3 and the outside air temperature sensor 5; And a discrimination circuit 10 for detecting snowfall based on the detection result of the moisture detection circuit 7 and the temperature detected by the temperature detection circuit 8.

The snow plate 1 has a pair of electrodes 1a and 1b on the surface, and the electrodes 1a and 1b are formed in a comb shape so as to be close to each other. As shown in FIG. 3, a conductive pattern 1f having a connection 1c to each of the electrodes 1a and 1b, a connection 1d to the temperature detection circuit 8, and a connection 1e to the outside air temperature sensor 5 is formed on the back surface of the snow plate 1. Are provided, and the snow plate temperature sensor 3 and the rectifying elements 4 and 6 are attached so as to contact the conductive pattern 1f. The snow receiving plate 1 includes a box-shaped case 1g, and is assembled so that the surfaces of the electrodes 1a and 1b are outside and covers the upper opening of the case 1g.

The heater 2 comprises a plurality of heating elements, and is mounted on a heat transfer plate 2a which is in surface contact with the back surface of the snow plate 1 and the inner side surface of the case 1g.

The snow plate temperature sensor 3 comprises a temperature detecting element such as a thermistor for detecting the temperature as an electric signal. One end of the snow receiving plate temperature sensor 3 is connected to the temperature detecting circuit 8 as shown in FIG. One rectifying element 4 is connected to one end side.

The first rectifying element 4 comprises a diode,
The other end is connected to the temperature detection circuit 8 so as to restrict the direction of current flow of the snow plate temperature sensor 3 from one end to only the other end.

The outside air temperature sensor 5 comprises a temperature detecting element such as a thermistor for detecting the temperature as an electric signal.
As shown in FIG. 4, one end is connected to the temperature detection circuit 8,
The other end is connected to one end of the second rectifier 6.
In this case, one end of the outside air temperature sensor 5 is connected to the temperature detection circuit 8 by a common wiring with the snow plate temperature sensor 3.

The second rectifying element 6 comprises a diode,
The other end is connected to the temperature detection circuit 8, and the direction of energization of the outside air temperature sensor 5 is restricted from the other end to only one end. In this case, the other end of the second rectifying element 6 is connected to the first rectifying element 4 by a common wiring so that the temperature detecting circuit 8
It is connected to the.

The moisture detecting circuit 7 includes the electrodes 1a,
1b, and detects that each of the electrodes 1a, 1b is short-circuited by moisture attached to the snow plate 1. The temperature detection circuit 8 is connected to the snow plate temperature sensor 3 and the outside air temperature sensor 5, and detects the temperatures of the snow plate temperature sensor 3 and the outside air temperature sensor 5 based on detection signals from the temperature sensors 3 and 5. I have. In this case, the temperature detection circuit 8 is connected to one end of the snow plate temperature sensor 3 and one end of the outside air temperature sensor 5 and the other end of each of the rectifying elements 4 and 6 via a switching circuit 8a as switching means. The polarity of the voltage applied to each of the temperature sensors 3 and 5 is alternately switched, thereby restricting the energization of each of the rectifying elements 4 and 6, so that the snow plate temperature sensor 3 and the outside air temperature sensor 5
Are detected alternately.

The heater control circuit 9 is connected to the heater 2 and the temperature detecting circuit 8, and drives the heater 2 when the temperature of the snow plate temperature sensor 3 detected by the temperature detecting circuit 8 becomes lower than a predetermined temperature. ing.

The discriminating circuit 10 is connected to the moisture detecting circuit 7 and the temperature detecting circuit 8, and the moisture detecting circuit 7
When the moisture adhering to the sensor is detected and the temperature detected by the outside air temperature sensor 5 detected by the temperature detection circuit 8 falls below a predetermined temperature, a snowfall detection signal is output to a snow melting device (not shown). .

In the snowfall detecting device configured as described above, when the temperature detected by the outside air temperature sensor 5 becomes equal to or lower than a preset snowfall allowable temperature and moisture adheres to the snow receiving plate 1, snowfall is detected. In this case, the water cannot be detected unless the snow falling on the snow receiving plate 1 melts. Therefore, when the temperature detected by the snow receiving plate temperature sensor 3 becomes lower than a predetermined temperature,
The heater 2 operates to prevent the temperature of the snow receiving plate 1 from lowering.

In the snowfall detection device, the temperature sensor 3 and the outside air temperature sensor 5 are arranged remotely from the main body 11 including the temperature detection circuit 8, and the temperature sensors 3, 5 One end and the other end are connected by a total of two common wires. That is, each of the temperature sensors 3, 5
Rectifying elements 4 and 6 are provided at one end of each of them so as to regulate the energization direction to only one direction so that the energization regulation directions of the temperature sensors 3 and 5 are opposite to each other. Since the detection signals of the temperature sensors 3 and 5 are alternately detected by alternately switching the polarity of the applied voltage, it is not necessary to provide a total of two wires for each of the temperature sensors 3 and 5.

As described above, according to the snowfall detection device of the present embodiment, one end and the other end of the snow plate temperature sensor 3 and the outside air temperature sensor 5 are connected to the device body 11 by common wiring. At the same time, rectifying elements 4 and 6 are provided at one end of each of the temperature sensors 3 and 5, and the polarity of the voltage applied to each of the temperature sensors 3 and 5 is alternately switched, so that the detection signal of each of the temperature sensors 3 and 5 is detected. Are alternately detected, there is no need to provide a total of two wires for each of the temperature sensors 3 and 5, and the wires for each of the temperature sensors 3 and 5 can be simplified. Further, since the temperature sensors 3 and 5 and the rectifying elements 4 and 6 are connected to the conductive pattern 1f provided on the back surface of the snow receiving plate 1, a board and the like for connecting these are separately required. Therefore, the efficiency of the parts assembling work can be improved.

[0021]

As described above, according to the snowfall detecting device of the first aspect, since it is not necessary to connect a plurality of wires for each temperature detecting element, the wiring to each temperature detecting means is simplified. Such as increased costs and poor connection
Problems associated with complicated wiring can be eliminated.

According to a second aspect of the present invention, there is provided a snowfall detecting device.
In addition to the effect of the first aspect, since there is no need to separately provide a board or the like for connecting each temperature detecting element and the rectifying element, it is possible to increase the efficiency of assembling parts.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a snowfall detection device according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of a main part of the snowfall detection device.

FIG. 3 is a perspective view showing a back surface of a snow plate.

FIG. 4 is a circuit diagram of a main part of the snowfall detection device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Snow plate, 2 ... Heater, 3 ... Snow plate temperature sensor, 4 ...
1st rectifying element, 5 ... outdoor temperature sensor, 6 ... second rectifying element, 8a ... switching circuit, 11 ... device body.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Mutsumi Murakami, Sanden Stock Company, 20 Kotobukicho, Isesaki-shi, Gunma

Claims (2)

[Claims] 1. A snow plate for detecting moisture attached to a surface, an outside air temperature detecting unit for detecting an outside air temperature, a snow plate temperature detecting unit for detecting a temperature of the snow plate, and heating the snow plate. And heating means to detect snowfall based on the detection temperature of the moisture detection of the snow plate and the outside air temperature detection means,
In a snowfall detecting device which controls the heating means based on the temperature detected by the snow plate temperature detecting means, a temperature detecting element for detecting the temperature of each of the outside air temperature detecting means and the snow plate temperature detecting means as an electric signal. Rectifying means for connecting one end side and the other end side of each temperature detecting element to the apparatus main body side by common wiring, and restricting the energizing direction to only one direction at one end side of each temperature detecting element. Wherein the temperature control elements are provided such that the directions of energization thereof are opposite to each other, and switching means for alternately switching the polarity of the voltage applied to each temperature detection element is provided. 2. A conductive member capable of mutually connecting a temperature detecting element as a snow receiving plate temperature detecting means, a temperature detecting element as an outside air temperature detecting means, and a rectifying element as a rectifying means on a back surface of the snow receiving plate. The snowfall detection device according to claim 1, wherein a pattern is provided.