JP2000147142A - Apparatus for detecting snowfall - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for detecting snowfall which can always surely grasp the intensity of a snowfall even when the snowfall amount is much. SOLUTION: The number of times of conduction per unit time of each paired electrode 2 set at a plurality of points of a snow-receiving plate 1 is counted, so that the intensity of a snowfall can be surely grasped even when the snowfall amount is much. In this case, the snow-receiving plate 1 is heated from 60 deg.C to 90 deg.C, thereby shortening the time for snow particles to evaporate after adhering to the snow-receiving plate 1. A probability for a next snow particle to adhere before the snow particle of the snow-receiving plate 1 completely evaporates can be reduced and an accuracy for measuring the intensity of the snowfall can be improved.

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 Japanese Utility Model Publication No. Sho 62-37183, a snow receiving plate having a pair of electrodes on its surface and an outside air temperature sensor for detecting an outside air temperature are provided. When the temperature falls below the temperature and it is detected that snow falls on the snow receiving plate and the electrodes are electrically connected to each other due to the water content of snow particles, a snow melting device attached to a road or the like is operated. Have been.

[0003]

By the way, in the snowfall detecting device, the intensity of snowfall can be detected by measuring the evaporation time of the snow particles attached to the snowboard.
In the case of a large amount of snowfall where the next snowdrops attach before the snowdrops on the snowplate completely evaporate, the intensity of the snowfall is detected because each electrode of the snowplate is continuously conducting. Therefore, there has been a problem that the operation of the snow melting apparatus cannot be properly controlled according to the snowfall intensity.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a snowfall detecting device capable of always accurately grasping the snowfall intensity even when the amount of snowfall is large. is there.

[0005]

In order to achieve the above object, according to the present invention, there is provided a snow receiving plate having a surface facing upward and a pair of a snow receiving plate and a predetermined position on a surface of the snow receiving plate. A plurality of electrode pairs each of which has a plurality of electrodes arranged thereon, and the electrical conduction of each electrode pair due to moisture attached to the snow plate is detected, and the number of conductions of each electrode pair per unit time is counted. Intensity measuring means. Thus, the number of conductions per unit time of each electrode pair provided at a plurality of locations on the snow plate is counted, so that it is possible to grasp the snowfall intensity even when the amount of snowfall is large.

According to a second aspect of the present invention, in the snowfall detecting device according to the first aspect, the snowfall intensity measuring means includes a signal switching circuit for sequentially switching a signal of each electrode pair, and each of the electrode pairs switched by the signal switching circuit. And a counting circuit for counting the number of signals per unit time exceeding the reference voltage of the voltage comparing circuit. Thus, in addition to the function of the first aspect, the signal of each electrode pair is sequentially switched by the signal switching circuit of the snowfall intensity measuring means and sent to the voltage comparison circuit.
Here, when each electrode of each electrode pair becomes electrically conductive due to the moisture of the snow particles attached to the snow plate, the voltage of the signal from each electrode pair changes and exceeds the reference voltage of the voltage comparison circuit. The number of times exceeding the reference voltage per unit time is counted by the counting circuit.

According to a third aspect of the present invention, in the snowfall detecting device according to the first or second aspect, a snow plate temperature detecting means for detecting a temperature of the snow plate, a heating means for heating the snow plate, Temperature control means for controlling the heating means so that the temperature of the snowboard becomes an arbitrary set temperature between 60 and 90 degrees Celsius. Thus, in addition to the function of the first or second aspect, the temperature of the snow receiving plate is heated to a temperature between 60 degrees Celsius and 90 degrees Celsius, so that the evaporation time of the moisture attached to the snow receiving plate is reduced. .

According to a fourth aspect of the present invention, in the snowfall detecting device according to the first, second or third aspect, a plurality of through holes corresponding to the respective electrodes of the respective electrode pairs are provided in the snow receiving plate, and the respective electrodes are respectively provided. Through the through-holes to the back surface of the snow plate, and one electrode of each electrode pair is connected to each other on the back surface of the snow plate. Thereby, in addition to the function of the first, second, or third aspect, the wiring to one electrode of each electrode pair is shared.

[0009]

1 to 5 show an embodiment of the present invention. FIG. 1 is a schematic structural view of a snowfall detecting device, FIG. 2 is an exploded perspective view of a main part thereof, and FIG. FIG. 4 is a circuit diagram of an electrode, and FIG. 5 is a flowchart showing the operation of the control unit.

This snowfall detection device includes a snow plate 1 disposed with its surface facing upward, a plurality of electrode pairs 2 provided on the surface of the snow plate 1, and a heater 3 for heating the snow plate 1. And a snow plate temperature sensor 4 for detecting the temperature of the snow plate 1, an outside air temperature sensor 5 for detecting the outside air temperature, and detecting the electrical continuity of each electrode pair 2 due to moisture attached to the snow plate 1. A snowfall intensity measuring unit 6 that measures the snowfall intensity and a control unit 7 that operates based on the measurement result of the snowfall intensity measuring unit 6.

The snow receiving plate 1 is formed of an insulating material, and is attached to the opening on the upper surface of the box-shaped case 1a with the surface facing outward. The case 1a has an electric wiring 1b.
Is inserted at one end.

Each electrode pair 2 has a pair of electrodes 2a.
The electrodes 2a are formed in a comb shape so as to be close to each other. Each of the electrodes 2a is connected to the snow receiving plate 1 through a plurality of through holes 1c provided in the snow receiving plate 1 as shown in FIG.
From the front surface to the back surface, and its surface is covered with nickel or gold plating 2b and carbon coating 2c. In this case, one electrode 2a of each electrode pair 2 is formed in an integrated pattern on the back surface of the snow plate 1, and is connected to one end of a power supply 2d via a common wiring. The other electrode 2a of each electrode pair 2 is connected to each rectifying and smoothing circuit 6a of the snowfall intensity measuring unit 6 by an individual wiring.
Connected to each other.

The heater 3 is composed of a plurality of heating elements that generate heat by electric power from a power source (not shown). The heater 3 is attached to a heat transfer plate 3a that is in surface contact with the back surface of the snow receiving plate 1 and the inner side surface of the case 1a. , The snow plate 1 is heated.

The snow plate temperature sensor 4 comprises a temperature detecting element for detecting the temperature as an electric signal.
a.

The outside air temperature sensor 5 is composed of a temperature detecting element for detecting the temperature as an electric signal, and is arranged at a place where the outside temperature is not affected by the heater 3. The outside air temperature sensor 5
Is connected to the gate circuit 6d of the snowfall intensity measuring unit 6.

The snowfall intensity measuring section 6 comprises a plurality of rectifying / smoothing circuits 6a for rectifying / smoothing the signals from the respective electrode pairs 2.
And a signal switching circuit 6b for sequentially switching the signal of each electrode pair 2 rectified and smoothed by each rectifying and smoothing circuit 6a, and comparing the signal of each electrode pair 2 switched by the signal switching circuit 6b with a predetermined reference voltage. A voltage comparison circuit 6c, a gate circuit 6d for transmitting a signal from the voltage comparison circuit 6c only when the detected temperature of the outside air temperature sensor 5 is lower than a predetermined temperature, and a unit time of a signal exceeding a reference voltage of the voltage comparison circuit 6c. It comprises a counting circuit 6e for counting the number of hits, and a timing circuit 6f for sending a pulse signal of a predetermined frequency to the signal switching circuit 6b and the counting circuit 6e.

The control unit 7 is constituted by a microcomputer, and includes a heater 3, a snow plate temperature sensor 4, and a counting circuit 6.
e and the boiler 8 of the snow melting apparatus. Control unit 7
In this example, the temperature of the snow plate 1 is set between 60 ° C. and 90 ° C., and the heater 3 is controlled so as to maintain the set temperature.

In the snowfall detecting device configured as described above, first, the signal of each electrode pair 2 is input to each rectifying / smoothing circuit 6a of the snowfall intensity measuring unit 6 and rectified and smoothed. Input to the circuit 6b. Next, the signal switching circuit 6b sequentially switches the input signal of each electrode pair 2 in synchronization with the pulse signal of the timing circuit 6f, and sends the signal to the voltage comparison circuit 6c. Here, each electrode 2a of each electrode pair 2 is electrically conducted by the moisture of the snow particles attached to the snow receiving plate 1,
As a result, when the voltage of the input signal changes and exceeds the reference voltage of the voltage comparison circuit 6c, the number of times the reference voltage per unit time has been exceeded is counted by the counting circuit 6e, and the counting result is used as the snowfall intensity as the control unit 7. Is output to At this time, the counting circuit 6e counts the time by the pulse signal of the timing circuit 6f, and repeats the process of resetting the count data to zero when the unit time has elapsed. If the temperature detected by the outside air temperature sensor 5 is not lower than the snowfall allowable temperature (for example, 0 ° C.), it is not sent out from the gate circuit 6d.
The signal of the voltage comparison circuit 6c is not input to the counting circuit 6e. That is, the control unit 7 controls the operation of the boiler 8 based on the snowfall intensity input from the snowfall intensity measurement unit 6.

Next, the operation of the control unit 7 will be described with reference to the flowchart of FIG. First, if the set temperature Ts is set within the range of 60 ° C. to 90 ° C. (S
1) The heater 3 is activated (S2). If the set temperature Ts is not set in the range of 60 ° C. to 90 ° C. in step S1, a predetermined error display is performed (S3).
It returns to step S1. Next, after the heater 3 is operated, if the detected temperature T of the snow plate temperature sensor 4 is lower than the set temperature Ts (S4), the driving power of the heater 3 is increased (S4).
5) Return to step S4. If the detected temperature T is not lower than the set temperature Ts and the detected temperature T is higher than the set temperature Ts in step S4 (S6), the driving power of the heater 3 is reduced (S7), and the process returns to step S4.

As described above, according to the snowfall detecting device of the present embodiment, the number of conductions per unit time of each electrode pair 2 provided at a plurality of locations on the snow receiving plate 1 is counted. Even in the case of a large amount, the snowfall intensity can be accurately grasped, and the operation of the boiler 8 can be appropriately controlled according to the amount of snowfall. In this case, by heating the snow receiving plate 1 to a temperature of 60 ° C. to 90 ° C., the time from when the snow particles adhere to the snow receiving plate 1 to when the snow particles evaporate is reduced. The probability that the next snow particle will adhere before the snow particle completely evaporates can be reduced, and the accuracy of snowfall intensity measurement can be improved. Further, since each electrode of each electrode pair 2 is extended to the back surface of the snow receiving plate 1 through the through hole 1c provided in the snow receiving plate 1, one electrode 2a is connected to a common wiring. The number of wirings to each electrode pair 2 can be reduced, which is advantageous in cost.

In the above embodiment, the hardware configuration of the snowfall intensity measuring unit 6 has been described. However, a part of the snowfall intensity measuring unit 6 may be configured by software using a microcomputer. For example, the signal switching circuit 6
b, voltage comparing circuit 6c, gate circuit 6d, counting circuit 6e
And a program having the function of the timing circuit 6f is stored in the control unit 7, and the signals of the rectifying / smoothing circuits 6a are A / A
The data may be D-converted, taken into the control unit 7, and processed by the control unit 7.

[0022]

As described above, according to the snowfall detecting device of the first aspect, even when the amount of snowfall is large, the snowfall intensity can be accurately grasped. Can be properly controlled.

Further, according to the snowfall detecting device of the second aspect,
In addition to the effect of the first aspect, the snowfall intensity measuring means can be realized by a hardware configuration, which is extremely advantageous for practical use.

According to a third aspect of the present invention, there is provided a snowfall detecting device.
In addition to the effect of the first or second aspect, the time from the attachment of the snow particles to the snow plate to the evaporation can be shortened, so that the next snow particles can be removed before the snow particles on the snow plate completely evaporate. The probability that the particles adhere can be reduced, and the accuracy of snowfall intensity measurement can be improved.

According to the snowfall detecting device of the fourth aspect,
In addition to the effects of the first, second, or third aspect, since the wiring to one electrode of each electrode pair can be shared, the number of wirings to each electrode pair can be reduced, which is advantageous in cost. is there.

[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 side sectional view of a main part of a snow plate.

FIG. 4 is a circuit diagram of an electrode.

FIG. 5 is a flowchart showing the operation of the control unit.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Snow plate, 2 ... Electrode pair, 2a ... Electrode, 3 ... Heater, 4
... Snow plate temperature sensor, 6 ... Snowfall intensity measuring unit, 6b ... Signal switching circuit, 6c ... Voltage comparison circuit, 6e ... Counter circuit, 7 ...
Control unit.

Claims (4)

[Claims] 1. A snow plate arranged with its surface facing upward, a plurality of electrode pairs each having a pair of electrodes arranged at predetermined positions on the surface of the snow plate, and a plurality of electrode pairs attached to the snow plate. A snowfall detecting device comprising: a snowfall intensity measuring means for detecting electrical conduction of each electrode pair due to moisture and counting the number of conductions of each electrode pair per unit time. A signal switching circuit for sequentially switching signals of each electrode pair; a voltage comparing circuit for comparing a signal of each electrode pair switched by the signal switching circuit with a predetermined reference voltage; 2. The snowfall detection device according to claim 1, further comprising: a counting circuit for counting the number of signals per unit time exceeding the reference voltage of the voltage comparison circuit. 3. A snow plate temperature detecting means for detecting the temperature of the snow plate, a heating means for heating the snow plate, and an optional setting wherein the temperature of the snow plate is between 60 and 90 degrees Celsius. 3. The snowfall detecting device according to claim 1, further comprising a temperature control unit that controls the heating unit so as to reach a temperature. 4. A plurality of through holes corresponding to each electrode of each electrode pair are provided in the snow receiving plate, and each electrode is extended to the back surface of the snow receiving plate through each through hole, and each electrode pair is provided. 4. The snowfall detecting device according to claim 1, wherein one of the electrodes is connected to each other on a back surface of the snow plate.