JPH0585035B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for detecting snow cover conditions for efficiently controlling snow melting equipment and the like.

[Prior art and issues]

Various snow melting devices have been known for melting snow from roads, roofs, etc., and for example, a snow melting/freezing device that efficiently melts snow from the approach from the gate to the entrance has already been published by the applicant in Utility Model Application No. 18507/1983. It is proposed in the official bulletin. This device has the heat collecting part of the heat pipe buried underground at a predetermined depth, and the heat dissipating part is placed in the snow-melting area.The heat collecting part is also equipped with an auxiliary heat source heater, which provides assistance during heavy snowfall. A heat source heater is activated to efficiently melt snow.

By the way, in order to control such auxiliary heat source heaters that do not need to be operated all the time, it is extremely efficient to accurately detect snow conditions and operate them only when necessary, reducing power consumption. be.

Therefore, it is possible to detect snowfall using a snowfall detector such as that disclosed in, for example, Japanese Patent Application Laid-open No. 50-45680, and operate a snow melting device according to the detection result.

However, conventional snowfall detectors melt snow that has fallen onto the board using a heater and detect the presence of melted water by measuring electrical resistance.
The snow melting device operates even when there is a small amount of snowfall that does not result in snowfall, making it unsuitable for a snow melting device that is intended to be used auxiliary only during heavy snowfall, such as the auxiliary heat source heater described above, and the structure of the snow melting device is There was a problem that was complicated and costly.

In addition, this type of snowfall detector usually uses a temperature sensor in combination to determine whether it is raining or snowing, but in reality, it snows even when the temperature is high.
On the other hand, because it rains even when the temperature is low, there was a problem in which accurate snowfall conditions could not be detected.

It is an object of the present invention to provide a snow cover state detection method that eliminates the problems existing in the prior art.

[Means to solve the problem]

In the present invention, a pair of electrodes 3 and 4 are arranged on the snow surface 2 _S of the snow melting area 2, and the electric resistance R _S between the electrodes 3 and 4 is
At the same time, the photometric sensor 11 placed above the snow melting area 2 detects the light reflectance or light reflection intensity of the snow covered surface 2 _S , and the detected electrical resistance R _S
is below a set value and the detected light reflectance (including light reflection intensity) M is above a set value, the snow cover state is detected to be snow melting when the electrode 3, 4 electrode surface 3 _S ,
_4S are exposed at the upper ends of the electrodes 3, 4 and insulated from the snow melting area 2, and the electrode surfaces _3S , _4S are set higher than the snow surface _2S by a predetermined height Ho. It is characterized by the following.

[Effect]

Next, the operation of the present invention will be explained.

According to the snow cover state detection method according to the present invention, the electrode 3 is insulated from the snow melting area 2 _S , and the electrode surfaces 3 _S and 4 _S are set higher than the snow melting area 2 _S by a predetermined height Ho. When the electrical resistance R _S between and 4 becomes less than or equal to the set value, a predetermined amount or more of moisture present on the snow surface 2 _S is detected.

In this case, due to the insulation between the electrode surfaces 3 _S and 4 _S and the snow melting area 2, for example, the electrical resistance of the concrete, etc. that constitutes the snow melting area 2 (usually about several hundred ohms)
The effects of In addition, electrode surfaces 3 _S and 4 _S
By setting H _O higher than the snow surface 2 _S by a predetermined height, the presence of a small amount of moisture, that is, a small amount of snowfall that does not pose a problem will not be detected.

On the other hand, since the presence of moisture may be due to rain, etc., the light reflectance M is detected, and when it exceeds a set value, it is determined that it is snowing.

〔Example〕

Below, preferred embodiments according to the present invention are listed,
This will be explained in detail based on the drawings.

The method of the present invention can be used to detect snow conditions and control the operation of a snow melting device only when there is snow that actually causes a problem.

First, an example of a snow melting device E that can utilize the method of the present invention will be described with reference to FIG. 2.

2 is a snow-melting area and shows the sidewalk W of the approach A from the gate to the entrance. The sidewalk W is made of concrete C, and a plurality of L-shaped heat pipes 7 have their heat collecting parts 7a buried at a predetermined depth underground, and their heat dissipating parts 7b are connected to the sidewalk W. Bury it in concrete C along the line. Further, an auxiliary heat source heater 8 is attached to the heat collecting portion 7a of each heat pipe 7 in contact therewith, and each heater 8 is connected to the controller 31. Each of these heaters 8 constitutes a snow melting device E. The controller 31 has a power supply control function for each heater 8 .

Next, the configuration of the snow melting control device 1 that determines the snowfall state and controls the energization of the auxiliary heat source heaters 8 according to the present invention will be described with reference to FIGS. 1 to 4.

First, a pair of electrodes 3 and 4 are attached to the sidewalk W. The electrodes 3 and 4 shown specifically in FIGS. 3 and 4 are formed of rectangular conductive plates having a predetermined thickness, and are buried in concrete C with a predetermined width apart and parallel to each other. be done. At this time, the conductor plate is covered with a water-repellent insulating material 20 to electrically insulate it from the concrete C. On the other hand, the conductor plates of electrodes 3 and 4 are on the snowy surface (concrete surface) _2S
The electrode surfaces 3 _S and 4 _S are made to protrude upward from the upper end.
is exposed, and the electrode surfaces 3 _S and 4 _S are made higher than the snow covered surface 2 _S by a predetermined height H ₀ . Note that the shapes of the protruding portions of the electrodes 3 and 4 relative to the sidewalk W are selected so as not to impede walking. On the other hand, the electrodes 3 and 4 are connected to the controller 31 via wires 23 and 24, respectively. The controller 31 includes an electrical resistance measuring circuit 32 to measure the electrical resistance R _S between the electrodes 3 and 4. This constitutes the electrical resistance detection section 5. And the measured electrical resistance
R _S is compared with a preset value in the judgment circuit 33, and when the measured value is less than the set value, it is "1",
When the set value is exceeded, "0" is output, and this signal is applied to the input side of the AND gate 34 via the connection switch 35.

Further, a reflective photometric sensor 11 using a light emitting element (light emitting section) and a light receiving element (light receiving section) is arranged above the sidewalk W, and this photometric sensor 11 is connected to the controller 31. The controller 31 includes a light reflectance measuring circuit 35 and measures the light reflectance M from the signal obtained from the photometric sensor 11. This constitutes a light reflectance detection section 9 that detects the snow cover state on the snow surface 2 _S using the light reflectance M. Then, the measured light reflectance M is compared with a preset value in the judgment circuit 36, and when the measured value is greater than or equal to the set value, it outputs "1", and when it is less than the set value, it outputs "0", and this signal is is applied to the input side of the AND gate 34.

On the other hand, a thermistor 26 is installed at a predetermined location outside, and this thermistor 26 is connected to the controller 31. The controller 31 includes a temperature measurement circuit 3.
8 to measure the outside air temperature To. This constitutes the temperature detection section 6. Then, the measured outside temperature To is compared with a preset value in the judgment circuit 39, and when the measured value is less than or equal to the set value, it outputs "1", and when it exceeds the set value, it outputs "0", and the signal is It is applied to the input side of the AND gate 34 via the connection switch 37.

The controller 31 also includes a connection switch 41.
The timer section 10 is connected via the. Timer section 10
has a built-in clock function, and the operating time t (operation start time and operation end time) can be set. Then, set "1" at the set operation start time and "0" at the operation end time.
This signal is applied to the input side of the AND gate 34.

On the other hand, the AND gate 34 connects the output side to the output circuit 4.
2. The auxiliary heat source heater 8 via the relay 43
Connect to...

In the above configuration, each connection switch 37 and 4
1 is such that the temperature detecting section 6 and the timer section 10 are selectively connected to the AND gate 34, so that they can be used depending on the climate, construction site, etc., if necessary.

Next, a snow cover state detection method according to the present invention will be explained.

First, when there is no snowfall, the electrical resistance R _S is in an insulated state, and the output of the determination circuit 33 is "0".
Therefore, the output of AND gate 35 also becomes "0",
The auxiliary heat source heater 8... is not energized. That is,
Snow conditions are not detected.

On the other hand, in the case of snowfall, the snow covered surface 2 _S of the sidewalk W gets wet, and when the snow accumulates to a certain extent, the amount of water increases due to the snow melting action of the heat pipe 7, and the electrical resistance between the electrodes 3 and 4 increases.
R _S decreases and the output of the determination circuit 33 becomes "1".

In this case, since the sidewalk W is always warmed by the snow melting action of the heat pipe 7 itself, there is no need to use the auxiliary heat source heater 8 when it snows a little, and it is necessary to increase the heating capacity only when it snows heavily. However, since the electrode surfaces 3 _S and 4 _S are set higher than the snow surface 2 _S by a predetermined height H _O , it is possible to reduce the amount of snow that does not accumulate, and even if the snow accumulates, it does not cause problems in real life. Snowfall is not detected. That is, as the snow accumulation progresses, the snow covered area becomes like a shear bed due to the snow melting action of the heat pipe 7..., and in order to form a water film of a predetermined height H, the height H _O of the electrode surfaces 3 _S and 4 _S is selected. In this way, a small amount of snowmelt water is not detected, and detection can be performed according to the desired snowfall amount.

In addition, since the electrode surfaces 3 _S and 4 _S are exposed at the upper ends of the electrodes 3 and 4, and the electrode surfaces 3 _S and 4 _S are insulated from the snow melting area 2, the concrete constituting the snow melting area 2 is The influence of the electrical resistance of C itself (usually on the order of several hundred ohms) is prevented.

By the way, when judged by electrical resistance R _S ,
The electrical resistance R _S will drop below the set value not only due to snowmelt water but also when there is a large amount of rainwater. Therefore, the light reflectance M is detected and the electrical resistance
Snow conditions can be detected by combining with R _S.
In other words, if snowfall occurs, the snowfall surface 2 of concrete C
_S becomes white and the light reflectance M also becomes large. At the same time, the electrical resistance R _S also decreases, making it possible to clearly detect snow accumulation. In this case, the outputs of the determination circuits 33 and 36 are both "1", which causes the above-mentioned
The output of the AND gate 34 becomes "1". Then,
Electricity can be applied to the auxiliary heat source heater 8. Note that even when the surface of the concrete C is dry and white, the output of the determination circuit 36 is "1", but in this case, the output of the determination circuit 33 in the electric resistance R _S detection system is "0". Therefore, snowfall is not detected. Further, in the case of rainwater, the surface of the concrete C becomes wet and becomes black, and the output of the determination circuit 36 in the light reflectance detection system becomes "0".

By the way, when detecting the snowfall state by the above method, the connection switch 37 or 4 may be
1 may be selectively turned on, and each determination element connected to each switch 37, 41 may be added. in this case,
The temperature detection unit 6 using the thermistor 26 gives "1" when the outside air temperature T _O falls below the set value, and for example, the judgment result based on the electrical resistance R _S and the light reflectance M detects the snow cover state. This can be used when you want to check the judgment result.

Moreover, the timer section 10 can also be connected and controlled. In general, it has been statistically clarified that the time of day when snowfall is most likely to occur is from around midnight to early morning, except during times of heavy snowfall. On the other hand, early snowfall is a problem in real life. Therefore, by energizing the auxiliary heat source heater 8 only during this time period, snow melting can be carried out efficiently without causing problems in real life. Therefore,
The AND gate 34 sets "1" to the operation start time set by the timer section 10 and "0" to the operation end time.
, the auxiliary heat source heater 8 can be energized only during the set predetermined operating time t.

In addition, electric resistance R _S , outside temperature T _O , light reflectance M,
The determination may be made by combining all the operating times t, or
Furthermore, determination may be made by combining other determining factors, and by combining them, reliability and certainty can be further improved.

Although the embodiments have been described in detail above, the present invention is not limited to these embodiments. For example, it can be widely applied to snow melting devices for any other applications. Other details such as composition, shape,
Arbitrary changes can be made in the arrangement, materials, etc. without departing from the gist of the present invention.

[Effects of the Invention] As described above, the present invention detects the electrical resistance between the electrodes by disposing a pair of electrodes on the snow surface of the area to be melted, and detects the light reflectance with a photometric sensor. In a snow condition detection method for detecting a snow condition that requires snow melting in response to a detection result, the electrode surface of an electrode is exposed at the upper end of the electrode, and is insulated from the snow melting area;
Since the electrode surface is set higher than the snow surface by a predetermined height, the following effects are achieved.

The electrode surface is exposed at the upper end of the electrode, and the electrode surface is insulated from the area to be melted, which prevents the influence of electrical resistance of the concrete, etc. that makes up the area to be melted, allowing accurate and reliable detection. It can be carried out.

By setting the electrode surface at a predetermined height above the snow surface, the snow melting device can be activated only when snow accumulation poses a problem in real life, enabling accurate and efficient snow melting control and reducing power consumption. , can contribute to energy saving. Further, detection can be performed according to the target amount of snowfall.

[Brief explanation of drawings]

Fig. 1: Block system diagram showing a snow melting control device capable of implementing the snow cover state detection method according to the present invention, Fig. 2
Figure: Overall configuration diagram of the snow melting control device, Figure 3: Plan view of the electrode in the snow melting control device, Figure 4: Vertical sectional view of the electrode. In the drawing, 2: Snow melting area, 2 _S : Snow covered surface, 3,
4: electrode, 11: photometric sensor.

Claims (1)

[Claims] 1 A pair of electrodes are placed on the snow surface of the snow melting area to detect the electrical resistance between the electrodes, and a photometric sensor placed above the snow melting area measures the light reflectance or light reflection intensity of the snow surface. In a snow cover state detection method that detects a snow cover state that requires snow melting when the detected electrical resistance is below a set value and the detected light reflectance or light reflection intensity is above a set value, the electrode of the electrode A method for detecting a snow cover state, characterized in that a surface is exposed at the upper end of the electrode, insulated from a snow melting area, and the electrode surface is set a predetermined height higher than the snow surface.