JPS60179648A - Snow detector - Google Patents

Abstract

PURPOSE:To detect snow accurately independently of the snowfall, the ambient temperature, air speed conditions, and difference of snow quality by controlling a device so that the temperature of a snow receiving plate is kept at a preliminarily set prescribed value. CONSTITUTION:The surface temperature of the snow receiving plate is monitored by a thermometer 13 attached to the snow receiving plate, and a difference between this temperature and a preliminarily set optimum temperature Ts of the snow receiving plate is operated by an operating circuit 15, and the temperature error signal is outputted to a current control circuit 16. The circuit 16 controls the supply current to a sheathed heater 3 of the snow receiving plate in accordance with the temperature error signal to set the surface temperature of the snow receiving plate to the preliminarily set optimum value, and a snowfall detection signal S is used for stopping the current to the heater in case of no snowfall. An ambient temperature TE is used for controlling the heater to set the surface temperature of the snow receiving plate to a certain required minimum temperature so that rain or water condensed as dews is not frozen in case of <=+2 deg.C and no snowfall.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a snowfall detection device for accurately detecting the start and end of snowfall in order to effectively operate a snow melting device or the like.

A conventional device of this type is shown in FIG. In the figure, (1) is the case, (2) is the electrode, (3) is the sheathed heater attached to the back of the electrode surface, (4) is the thermometer,
(5) is a lead wire that transmits the electrode signal to the control system, (6)
(7) is a lead wire that transmits temperature data to the control system, and (7) is a lead wire that supplies power to the heater. FIG. 2 is a schematic diagram of the control system of this device. In the figure, (8) is the electrode (2
), the switch (9) is activated by the signal from the thermometer (
4), αO is the relay operated by (8) (
9) is a relay that is activated when it is activated, and (11) is the main power supply circuit for a snow melting device, etc. Vs is the power supply of relay oO, V
H is a power source for the snow board heater (3).

Next, the operation will be explained. The sheathed heater (3) built into the snowfall detection device main body (1) is always in an ON state. When it snows, the snow accumulated on the main body (1) of the snowfall detection device is warmed and immediately turns into water droplets and flows, and at this time, the two electrodes (2) are short-circuited by the water droplets. This short circuit signal is transmitted through the lead wire (5) and the control system switch (8) is turned on.

In order to distinguish between snowfall and rain, a separate thermometer (4) is installed and sends temperature data to the control system via a lead wire (6). The outside temperature during snowfall is below +2°C, and when the outside temperature falls below +2°C, the control system relay (9) turns ON.
becomes. When the relays (8) and (9) are turned on, it means that snow has started to fall, and the relay switch Q1 is activated to turn on the main power supply circuit Qυ and operate the snow melting device and the like. When the snow stops falling, since the electrode (2) is tilted, all the water droplets will flow down and the short-circuited state of both electrodes (2) will return to the disconnected state. For this reason, the control system relay (8) is turned OFF.
Accordingly, relay 00 is also turned off, disconnecting the main power supply circuit αυ and stopping the operation of the snow melting device and the like.

As described above, in the conventional snowfall detection device, since the amount of heat generated by the sheathed heater of the detection device is constant, the detection sensitivity is greatly inferior when the outside temperature changes significantly.

For example, if snow falls with a load smaller than the snow melting load of the heater, the water will evaporate before the electrodes are short-circuited.

In addition, if snow falls with a load greater than the snow melting load of the heater, there is a drawback that even if the snow stops falling, a short circuit occurs and the main power source of the snow melting device remains on until the snow melts. Additionally, the snow melting ability of the heater in the detection device changes depending on the ambient temperature and wind speed, making it impossible to accurately detect snowfall.

Furthermore, depending on the size of the snowflake, water droplets may evaporate before short-circuiting, making accurate detection impossible.

This invention was made in order to eliminate the drawbacks of conventional ones such as 1 gloss, and by controlling the amount of current supplied to the snow plate heater so as to keep the temperature of the detection plate at a predetermined value, it is possible to control the amount of snowfall. Reduce the amount of power supplied to the heater to prevent evaporation when the ambient temperature is relatively high or when the ambient temperature is relatively high; To provide a snowfall detector capable of accurately detecting the start and end of snowfall regardless of the amount of snowfall, ambient temperature, and wind speed by increasing power supply and snow melting ability to prevent snow from remaining. The purpose is to

An embodiment of this invention will be described below. In FIG. 8, α is a thermometer that detects the surface temperature of the snow receiving board, and α is a lead wire that sends temperature data from the thermometer to the outside. The other parts have the same structure as the conventional device (FIG. 1). FIG. 4 is a schematic diagram of the control system of the device according to the invention. α葎 is the above-mentioned thermometer, aQ is the snow board temperature and the set temperature T
aQ is an arithmetic circuit that determines the amount of current to be supplied to the snow board heater (3) according to s, and aQ is an arithmetic circuit (a current control circuit that controls the current supplied to the heater (3) in response to the Ryuko command signal from ll'9). TE is the ambient temperature measured by the thermometer (4), S
indicates a snowfall detection signal from relay 01.

The snow melting operation is the same as the conventional device. Here, the control operation of the sheathed heater (3) of the snow board will be explained. In the conventional device, the calorific value of the sheathed heater (3) of the snow catch plate was constant, but in the present invention, the temperature of the snow catch plate surface is monitored with a thermometer 03 attached to the snow catch plate, and the temperature is set in advance. A calculation circuit αG calculates the difference from the optimum snow plate temperature Ts, and outputs the temperature error signal to the current control circuit α. The current control circuit at3 controls the current supplied to the sheathed heater (3) of the snow board in response to the temperature error signal. In other words, the snow board surface temperature is always kept at a preset optimal value (for example, +
Heater (3) so that the temperature is 10℃~+20℃)
Controls the current supplied to the The snowfall detection signal S is used to stop the current to the sheathed heater (3) of the snow plate in order to avoid wasting power when there is no snow falling.

In addition, the ambient temperature TE requires the surface temperature of the snow catcher to prevent rain (the snowfall detector does not detect rain) or condensed water from freezing on the snow catcher when the temperature is below +2°C and there is no snowfall. It is used to control the sheathed heater (3) to maintain a minimum constant temperature (eg +2°C to 8°C).

As described above, according to the present invention, by controlling the calorific value of the sheathed heater for snow catchers and appropriately setting the maximum calorific value of the heater, it is possible to detect the end of snowfall and the beginning of snowfall depending on the amount of snowfall and the surrounding temperature. This method has the advantage of being able to accurately detect wind speeds and snow quality regardless of differences in wind speed and snow quality, and therefore being able to respond to various geographic conditions with different weather conditions. It also has the effect of energy saving by reducing power consumption under conditions without snowfall. Figure 2 is a schematic circuit diagram of the control system, Figure 8 is a schematic perspective view of a snowfall detection device according to an embodiment of the present invention, and Figure 4. is a schematic circuit diagram of the control system.

(1)...Box, (2)...Electrode, (3)...Snow board heater, (4) Wheel...Thermometer, (5) (6) (
7) α→...Lead wire, (8) (9)...Relay contact, 00...Relay, (B)...Snow melting device main circuit, (6)...Snow plate heater, 0Q... Arithmetic circuit,
αQ...Current control circuit, Ts...Set temperature, TE・
...Ambient temperature, S...Snowfall detection signal, Vs...Relay power supply, vH...Heater power supply.

Note that the same reference numerals in the figures indicate the same or equivalent parts.

Agent Masao Oiwa Figure 1 Figure 2

Claims (2)

[Claims] (1) In a snowfall detection device that detects snowfall by heating a snow catch plate, melting the snow on the snow catch plate, and detecting its moisture, the temperature of the snow catch plate is set to a predetermined temperature. 1. A snowfall detection device characterized by comprising a control device that maintains the snowfall at a certain value. (2) The control device includes a temperature detection means that detects the temperature of the snow catcher, and a calculation that calculates the amount of electricity to be supplied to the heater that heats the snow catcher from the temperature detected by the temperature detector and a set value. 2. The snowfall detection device according to claim 1, comprising: a circuit; and a control circuit that controls the amount of electricity supplied to the heater in accordance with the output of the arithmetic circuit.