JPH11142261A - Snow-ice detection method in relation to thaw-frosting prevention to roof, road, etc. - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent damages, breaks to a sensor and eliminate maintenance by indirectly sensing snowing and frosting from changes of a heat flow density and a temperature. SOLUTION: A heater ground 21 is formed on a road face ground 25, and a sensor part 22 is buried at a position of several cm from a front face of a pave material 21. Snowing, frosting on the front face of the pave material 21 is sensed from changes of a heat flow density and a temperature, thereby controlling the operation of a road heater 23. The sensor part 22 is buried inside the pave material 21 and therefore not directly influenced by a road face load or deteriorated by ultraviolet rays. Without any exposed part, the sensor part is not broken by an external factor. Furthermore, cleaning for a sensor sense face or the like maintenance is eliminated. Many troubles are thus solved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for preventing snow melting and freezing, in which snowfall and icing are determined by a change in heat flow density and a change in temperature.
The present invention relates to a method for sensing snow and ice in which snow and ice are not sensed directly in contact with a sensor but indirectly sensed via a roofing material or a pavement material.

[0002]

2. Description of the Related Art It is known to use a sensor for detecting snow or ice when performing snow melting or freezing prevention. However, the method for detecting such snow or ice is generally as follows. The first type of sensor directly touches the sensing surface of the sensor with snow or ice, melts it with the heat of the heater built into the sensor, converts it to water, measures the electric resistance of the water, and reduces the outside air to 5. If it is below ℃, it is judged as snow or ice. The second type is an infrared transmitter / receiver that is installed at an appropriate interval and detects when the emitted infrared beam is directly blocked by snowfall. The third type receives snow directly in a cup and switches on the weight. The fourth type uses a diffuse reflection type infrared sensor to measure the reflected waves that directly reflect the emitted infrared rays on the falling snow particles, and then turn on the switch. The fifth type emits ultrasonic waves or infrared rays toward the snow surface, measures reflected waves from the snow surface, and turns on the switch. There are a variety of snow and ice sensing methods, but all of them have a structure in which the sensor part is exposed because of the method of directly sensing snow and ice.

[0003]

A sensor for detecting snow and ice is required to be installed in a place where snow melting or freezing is prevented, and the sensor must be mounted with the sensor portion exposed. In order to install the sensor part on the pavement surface in the exposed state, the sensor part is designed to be extremely large to withstand the load of the passing vehicle and the strength of the sensor part is designed and manufactured. For this reason, there were many problems in that the design was uncomfortable and the sensor part was damaged by external factors. Even in the case of snow melting and freezing prevention on the roof surface, in order to attach the sensor part to the upper part of the roof surface and the place where you can catch snowfall directly,
For example, the type that is mounted on the roof surface has problems such as falling damage due to falling snow, UV deterioration and oxidation of the sensing surface, etc. There were many problems that could not be easily solved, such as the problem of aesthetics, the problem of aesthetics, and the damage to birds such as crows.

[0004]

According to the present invention, the problem of the prior art is not to be mounted by exposing a sensor portion for sensing snow or ice, but to be applied to a roofing material 31 as shown in FIGS. It is an object of the present invention to provide a method of sensing snow and ice which can be attached to the lower part of the paving material 21 to solve the problem.

[0005] Rather than sensing snow or ice directly in contact with the sensor portion as in the prior art, the roof material 31 and the pavement material 2 are not detected.
In order to be able to indirectly detect the heat flow through the sensor 1 or the like, a heat flow generating heater 2 for generating a heat flow by itself is built in the sensor portion, and a heat flow density sensor 3 for measuring the density of the generated heat flow on one side below the sensor. And a temperature sensor 4 for measuring a temperature change of the heater for generating heat flow is arranged on another side, and these are housed in a sealed case composed of the upper panel 1, the lower panel 5, and the outer spacers 6a, 6b. Then, the lead cable 7 is taken out from a part of the outer peripheral spacer.

When snow or ice does not exist on the surface of the roof material 31 or the pavement material 21 and the surface is in a dry state, the heat value of the heat flow generating heater 2 and the heat transfer coefficient of the roof material 31 or the pavement material 21 are obtained. 3A and 3B, the output of the heat flow density sensor changes as shown in FIGS. 3A and 3B under the influence of wind and solar heat. Since the surface on which the sensor portion of the roofing material 31 and the pavement material 21 is heated is heated by the heat, the snow and ice that has fallen on that portion melt to become water, and the roofing material 31,
The pavement material 21 is deprived of heat of fusion.

When the heat of fusion is deprived, the heat distribution in that portion changes, and a heat flow occurs toward the portion where the temperature has decreased, and the heat flow largely moves, so the heat load of the heat flow generating heater 2 also changes. The temperature of the heat flow generating heater 2 gradually decreases. At this time, the heat flow density sensor 3 is attached in close contact with the lower surface of the heater 2 for generating heat flow, and as a characteristic of the heat flow density sensor, the change in the output signal is extremely small for a gradual temperature change, but measurement is difficult. As shown in FIGS. 3B to 3C, immediately after the rapid temperature change starts, the output signal of the heat flow density sensor changes at this time because it has the property of outputting a signal output much larger than the actual heat flow density change. Is big.

When this change is detected, the beginning of snowfall or icing can be caught, so that the snowmelt / freeze prevention heater is operated to perform snowmelt / freeze prevention. After that, when snowfall and icing are completed, the temperature of the heat flow generation heater gradually recovers, but the level change of the output signal of the heat flow density sensor is extremely small, so it is difficult to know the completion time of snow melting and freezing prevention. The temperature change of the heater for heat flow generation is measured by the temperature sensor 4, and the temperature of the heater for heat flow generation after completion of snow melting and freezing increases by adding the heat generated by the roof heater and road heater provided for preventing snow melting and freezing. By setting this temperature and FIG. 3D, the completion point is grasped and the heater is stopped.

[0009]

In this manner, the change in the density of the heat flow emitted from the sensor portion mounted in a non-exposed manner under the roof material 31 or the pavement material 21 is reversed by the characteristic of the heat flow density sensor, which should be considered as a defect. In addition, the start of melting of snow and ice is caught from the movement of heat flow, and the end point of snowfall and icing, which is difficult to detect with a heat flow density sensor, can be correctly measured by measuring the temperature rise of the heater for heat flow generation. This is a snow and ice sensing method that senses and controls the heater, and suppresses deterioration of the sensor part by concealing or burying the sensor part, does not adversely affect the aesthetics of buildings, etc., and does not require maintenance. .

[0010]

FIG. 4 shows an embodiment in a road or a parking lot. The heater base 25 is formed on the road base 25, and the sensor unit 22 is buried and installed at a position about several centimeters from the surface of the paving material 21. Thereby, it is detected that snowfall and icing have occurred on the surface of the pavement material 21, and the operation of the road heater 23 is controlled. Sensor part is paving material 2
Since it is buried inside 1, there is no direct load on the road surface, no UV deterioration, and there is no exposed part in the sensor part, so there is no damage due to external factors.

FIG. 5 shows an embodiment on a roof surface. A waterproof paper (roofing) 34 is laid on a base plate 35 of the building, a roof heater 33 and a sensor unit 32 are arranged thereon, and the roof material 31 is laid. The time when snowfall and icing has occurred on the roofing material 31 and when the snowfall and frosting have ended is caught, and the operation of the roof heater 33 is controlled to prevent snowmelt and freezing. Since the sensor part is installed under the roof material 31 as in FIG.
It does not affect the aesthetics of the roof and the sensor does not get damaged by falling snow on the roof.

[0012]

According to the present invention, the method of sensing snow and ice can be indirectly sensed through a building material such as a pavement material or a roofing material, instead of directly sensing snow and ice in the conventional manner. As a result, there is no restriction on the mounting location of the sensor part, the design is not broken, damage to the sensor part due to impact etc., damage accidents can be prevented, and maintenance such as cleaning of the sensing surface is unnecessary It can solve many troubles.

[0013]

[Brief description of the drawings]

FIG. 1 is a top view of a snow and ice sensor of the present invention. The left and right sides of the figure show a state in which a part of the upper panel 1 is broken.

FIG. 2 is a side sectional view of the snow and ice sensor of the present invention. The drawing is greatly enlarged in the thickness direction.

FIG. 3 is a diagram showing a change in temperature of a heat flow generating heater;
It is the figure which expressed the relationship with the signal output of a heat flow density sensor simply.

FIG. 4 is a cross-sectional view of an embodiment for preventing snow melting and freezing on a road.

FIG. 5 is a sectional view of an embodiment for preventing snow melting and freezing at a roof eave.

[Explanation of symbols]

 1: Upper panel 2: Heat flow generator heater 3: Heat flow density sensor 4: Temperature sensor 5: Lower panel 6a: Outer peripheral spacer 6b: Outer peripheral spacer 7: Lead cable 21: Pavement material 22: Sensor part 23: Road heater 24: Heater Base 25: Road surface 31: Roof material 32: Sensor 33: Roof heater 34: Waterproof paper (roofing) 35: Field board

Claims (1)

[Claims] (1) A method in which a heater is installed on the roof of a building or a road to detect snowfall or icing, and the heater is operated to prevent snow melting and freezing on the roof or the road. (C) The lower part of the roof material on the roof surface and the lower part of the pavement material such as roads, incorporating a sensor that measures the change in heat flow density, a temperature sensor, and a flat heater for generating heat flow. To measure the density of the heat flow generated by the heater for heat flow generation, which greatly changes when snowfall or icing starts, and measures it together with the temperature change to provide the sensor with (d) Roofs for preventing snow melting and freezing on roofs and roads, characterized by sensing snowfall and icing indirectly through roofing materials and paving materials without directly contacting snow and ice. How to detect snow and ice for prevention of snow melting and freezing on roads Law.