JP2001020210A - Snow melting pavement utilizing induction heating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a snow melting pavement with a small adverse effect for a living body capable of efficiently melting snow by laying an induction coil between a pavement surface and the roadbed formed by laying a metal plate body comprising a conductive material on a roadbed. SOLUTION: Metal plate bodies 14... comprising a conductive material is laid on roadbeds 16, 16 to form a pavement surface 12. Induction coils 20... formed by burying a flat winding in a flat plate rubber body are laid close to the lower face of the pavement surface 12 between the pavement surface 12 and the roadbed 16. When alternating current is supplied to the induction coil 20, joule heat generated in the inside is much because an object to be heated by electromagnetic induction is the metal plate body 14 of a wide area, and efficient snow melting can be performed. Furthermore, an electromagnetic wave leaked to the outside of the pavement surface 12 lessens, and an adverse effect for a living body can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a snow melting pavement having a function of melting snow accumulated on a pavement surface.

[0002]

2. Description of the Related Art Conventionally, an apparatus for melting snow accumulated on a pavement or the like by using induction heating is disclosed in Japanese Patent Publication No. 61-47.
No. 247 discloses a snow melting apparatus. As shown in FIG. 11, one or several rows of electric heaters 104 covered with a heat insulating insulator 102 are buried at a certain depth from a snow surface 100 as shown in FIG. 100 is mixed with a powder 108 made of a conductive metal to form a heating element. Here, the electric heating element 104 is formed in a coil shape, and an eddy current is generated in the powder 108 by electromagnetic induction by flowing an alternating current through the electric heating element 104. The eddy current generates Joule heat in the powder body 108, and can melt the snow accumulated on the snowfall surface 100. In addition, 110 is a roadbed on which a pavement is installed.

[0003]

However, in the above-described configuration, since the eddy current generated in each of the powders 108 is small, the amount of heat generated by the powders 108 as a whole is also small.
There is a problem that efficient snow melting cannot be performed. In addition, the structure in which the heat insulating layer 106 is interposed between the electric heating element 104 and the snowfall surface 100 requires a lot of time and labor for construction, and the distance between the electric heating element 104 and the snowfall surface 100 is increased.
There is also a problem that an eddy current generated in the powder body 108 is reduced due to a reduction in the amount of the AC magnetic field generated by the electric heating element 104 reaching the powder body 108 included in the zero, and snow melting cannot be performed efficiently. When considering the influence of electromagnetic waves on living organisms such as people and animals passing on the snowfall surface 100, it is important to prevent the lines of magnetic force from leaking upward from the snowfall surface 100. 100 powdery substance 108
In the case of the configuration in which is mixed, it is considered that the magnetic flux leaking above the snowfall surface 100 through the gap between the powdery bodies 108 increases, and there is also a problem that the risk of adversely affecting the living body increases.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to solve the above-mentioned problems, and an object of the present invention is to provide a snow-melting pavement utilizing induction heating which can perform efficient snow-melting and is less affected by electromagnetic waves to a living body. is there.

[0005]

According to the present invention, in order to solve the above-mentioned problems, a snow melting pavement utilizing induction heating according to claim 1 is formed by laying a metal plate made of a conductive material on a roadbed. A pavement surface, and an induction coil formed by burying a flat winding in a flat rubber body, and being laid between the pavement surface and the roadbed near the lower surface of the pavement surface. It is characterized by. According to this, since the object to be induction-heated by electromagnetic induction is not a microscopic substance such as a conventional powdery substance but a metal plate having a larger area, Joule heat generated inside increases, Efficient snow melting can be performed. In addition, the amount of electromagnetic waves leaking to the outside of the pavement surface is reduced, and the adverse effect on the human body can be reduced. Further, since the flat winding is buried in the rubber body, even if the flat winding is disposed close to the lower surface of the pavement surface, the external force received from the pavement surface is less likely to be damaged by the rubber body. And since it can be arrange | positioned close to the lower surface of a pavement surface, the generated alternating magnetic field can be efficiently supplied to a pavement surface, and efficient heating can be performed.

It is preferable that the pavement surface is formed by laying a plurality of the metal plate members, and the joint portions of the metal plate members overlap each other. Normally, a metal plate is formed in a predetermined size that can be handled by a person, and a plurality of the metal plates are laid to form a pavement surface, but even in such a case, the joint portions of the metal plates overlap each other. By doing so, the leakage of electromagnetic waves can be reduced, and a snow melting pavement safe for the human body can be provided.

[0007] In addition, a structure is provided on the lower surface of the metal plate to provide a leg for forming a space between the lower surface of the induction coil and the roadbed. Prevents the load of a living body from being directly applied to the induction coil, preventing disconnection of the induction coil, etc., and disposing heat insulating material in this space prevents the heat generated in the metal plate from escaping to the roadbed side. This allows efficient snow melting on the pavement surface.

According to a fourth aspect of the present invention, there is provided a snow melting pavement utilizing induction heating, wherein a pavement surface formed by laying a hollow metal box made of a conductive material on a roadbed and an inner upper surface of the metal box. And an induction coil laid in close proximity. According to this, since the induction coil is surrounded by the conductive material, the leakage magnetic flux is extremely reduced, and a snow melting pavement safer for the human body can be realized. Also,
Because the induction coil is arranged inside the metal box,
Even when the metal box is laid close to the inner top surface, external force from the pavement surface is not directly applied to the induction coil, preventing the induction coil from breaking, etc., and efficiently supplying the alternating magnetic field generated to the pavement surface. And efficient heating can be performed.

A power supply for supplying an alternating current to the induction coil, a temperature sensor for measuring the surface temperature of the pavement surface, the surface temperature is detected via the temperature sensor, and the detected surface temperature is determined in advance. When the temperature becomes equal to or lower than the set first temperature, the supply of the alternating current from the power supply unit to the induction coil is started, and the detected surface temperature becomes the second temperature higher than the preset first temperature. And a control unit for stopping the supply of the alternating current from the power supply unit to the induction coil when the temperature reaches the first temperature. For example, by setting the first temperature to zero degrees and setting the second temperature to about plus several degrees. When snow is likely to accumulate on the pavement surface, the pavement surface is heated in advance to prevent snow accumulation, and the power consumption can be reduced by preventing the pavement surface from being heated more than necessary. In addition, even if the amount of snow is large, even if it becomes snowy, it will be melted,
When the snow disappears, the supply of the alternating current can be stopped.

A power supply for supplying an alternating current to the induction coil, a snow sensor for detecting the snow condition on the pavement surface, and a snow condition on the pavement surface are detected via the snow sensor to detect snow. In such a case, even in a configuration including a control unit that supplies an alternating current from the power supply unit to the induction coil, snow melting with little power consumption can be performed by automatically detecting snow cover.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a snow melting pavement utilizing induction heating according to the present invention will be described below in detail with reference to the accompanying drawings. (First Embodiment) First, the structure of a snow melting pavement 10 using induction heating will be described with reference to FIGS. The pavement surface 12 through which living bodies such as humans and animals actually pass is formed by laying a metal plate 14 made of a conductive material on a roadbed 16. In detail, the formation site of the pavement of the roadbed 16 is slightly dug down, sand for level adjustment 18 is laid, and the metal plate 14 is laid thereon. Then, the thickness of the level adjusting sand 18 is adjusted so that the surface of the metal plate body 14, that is, the pavement surface 12 is adjusted.
Of the surface of the roadbed 16 is usually adjusted to the height of a portion of the roadbed 16 other than the pavement. Here, the material of the metal plate 14 is preferably steel such as ductile cast iron in consideration of strength and toughness, but may be non-ferrous metal such as copper or titanium. In addition, the shape of the surface of the metal plate 14 may be formed into various shapes in consideration of the use conditions, such as forming irregularities so as not to be slippery, or having the same shape as the guide tile for the blind. Can be.

The lower surface of the pavement surface 12 (in other words, the lower surface of the metal plate 14 constituting the pavement surface 12) is located between the pavement surface 12 and the roadbed 16 located below the pavement surface 12. The induction coil 20 is laid. Here, the concept of “close to the lower surface” includes a case where the induction coil 20 is laid directly in close contact with the lower surface of the pavement surface 12. And this induction coil 20
As shown in FIG. 3, a flat winding 24 is embedded in a flat rubber body 22 and formed. Accordingly, even if the induction coil 20 is disposed close to the lower surface of the metal plate 14 constituting the pavement surface 12, even if pressure is applied from the metal plate 14, the pressure received from the pavement surface 12 can be improved. Is alleviated by the rubber body 22, so that the possibility of damaging the flat winding 24 through which current flows is reduced. And since it can be arranged close to the lower surface of the pavement surface 12, the induction coil 2
The alternating magnetic field generated at 0 can be efficiently supplied to the pavement surface 12, and each metal plate 14 can be efficiently heated.

Since the purpose of the flat type winding 24 is to generate an induced magnetic field by a flowing alternating current, it is not preferable that the flat type winding 24 itself generates heat as a resistance. Therefore,
As shown in FIG. 4, it is formed by collecting a plurality of wires having a small cross-sectional area and winding a wire having an increased surface area so as to reduce the resistance value to the alternating current. In this case, in order to make the flat windings 24 thin, it is desirable to use wires having a small cross-sectional area in a flat arrangement. Note that, depending on the frequency of the alternating current, the flat wire 24 can be formed using a single wire as shown in FIG. 5 as a wire, and if the current can be small, it is not shown, The flat winding 24 can also be formed by printed wiring.

Further, the pavement surface 12 of the present embodiment is formed by laying a plurality of metal plate bodies 14 having a square planar shape in a grid pattern as shown in FIG. As shown in FIG. 6, the shape of each metal plate 14 is formed on the lower surface of a pair of opposed edges (upper and lower edges in FIG. 6B) along the legs 26 along the edges. Is formed, as shown in FIG. 6C, the front shape is formed in a U-shape, and the end face shapes of the other pair of edges are such that the joint portions of the adjacent metal plate bodies 14 overlap each other. It has a structure. The structure of a specific joint portion will be described. An end surface of one of the other pair of edges (the right edge in FIG. 6B) of the metal plate body 14 has an inner surface. A fitting projection 28 extending from one leg 26 to the other leg 26 is formed along the other edge (see FIG. 6).
A fitting recess 30 into which the fitting projection 28 fits is formed on the end surface of the left edge portion ((b) in the middle) so as to extend from one leg 26 to the other leg 26 along the inner surface. Have been. The leg 26 is formed not only on the lower surface of the pair of opposing edges of the metal plate 14 but also in a central region of the metal plate 14 as shown in FIG. As described above, various modifications can be made such as a structure having strength against pressure from above.

When the metal plate 14 is laid,
As shown in FIG. 2, the legs 26 formed on a pair of edges of the adjacent metal plate members 14 are connected to each other by a connector 32 having a U-shaped cross section so as not to be separated from each other. As shown in FIG. 8, the other pair of edges is connected to one metal plate 14.
Is inserted into the fitting concave portion 30 of the other metal plate body 14 and the joints between the adjacent metal plate bodies 14 are connected so as to overlap each other. Due to the structure of the metal plate 14 (the structure in which the leg portions 26 are formed) and the connection structure of the metal plates 14, the joints are arranged below the metal plates 14 laid along the direction in which the joints overlap each other. The space A surrounded by the lower surface of each metal plate 14, the pair of legs 26 of each metal plate 14, and the upper surface of the roadbed 16 is
It is formed so as to penetrate. Therefore, the induction coil 20 is extended over the plurality of metal plates 14 using the space A.
Can be arranged close to the lower surface of the metal plate 14.

Further, in the present embodiment, the space A
Is greater than the thickness D of the induction coil 20, the heat insulating material 34 is disposed in a region below the space A formed between the lower surface of the induction coil 20 and the roadbed 16. Thereby, the heat generated in the metal plate 14 can be prevented from escaping to the roadbed 16 side, and the snow melting on the pavement surface 12 can be performed more efficiently. A leg 26 extends downward from the lower surface of the pair of edges of the metal plate 14, and the other pair of edges of the metal plate 14 It overlaps the edge of the body 14. With this structure, the conventional powdery material 108
The leakage of the magnetic field generated by the induction coil 20 above the pavement surface 12 is remarkably reduced as compared with the case where is heated by electromagnetic induction. Therefore, the influence of the magnetic field on the living body such as a human or an animal passing on the pavement is reduced, and the risk of adversely affecting the living body is extremely reduced.

Further, as shown in FIG. 1, the supply of the alternating current to the induction coil 20 is performed from a power supply section (constituted by an inverter or the like) 36 for generating an alternating current having a predetermined frequency. The power supply from the power supply unit 36 to the induction coil 20 can be turned on and off manually by an operator, but in the present embodiment, the snow condition on the pavement surface can be automatically detected and performed. It has a structure. Therefore, pavement surface 12
The control unit 40 detects the surface temperature of the pavement surface 12 via the temperature sensor 38, and the detected surface temperature is set to a preset first temperature.
When the temperature becomes lower than the temperature, the power supply unit 36 supplies the induction coil 2
0, and then the melting of snow proceeds, and the detected surface temperature of the pavement surface 12 is set to a first preset value.
When the temperature reaches the second temperature higher than the temperature, the supply of the alternating current from the power supply unit 36 to the induction coil 20 is stopped. Control unit 40
Can be realized using, for example, a computer or a sequencer.

The first temperature is set to, for example, near zero degree (for example, a temperature in the range of −several degrees C. to + several degrees C., for example, + 4 ° C.), and the second temperature is higher than the first temperature. By setting the temperature (for example, + several degrees Celsius, for example, +5 degrees Celsius as one specific example), the alternating current is automatically supplied to the induction coil 20 when the temperature at which the possibility of snow accumulation on the pavement surface 12 is reached. The control unit 40 controls the power supply unit 36 so that the pavement surface 12 is heated in advance to prevent snow accumulation, and that the pavement surface 12 is not heated more than necessary to reduce power consumption. In addition, when the snow amount is large and the pavement surface 12 is heated despite the heating of the pavement surface 12, the temperature of the pavement surface 12 detected via the temperature sensor 38 does not rise, so that the induction coil 20 is continuously turned on. , An alternating current can be supplied to maintain a state in which snow can be melted, and when the snow melts and disappears, the temperature of the pavement surface 12 detected increases, and the supply of the alternating current is stopped.

As a method for judging whether or not the pavement surface 12 needs to be heated by supplying an alternating current to the induction coil 20, the temperature sensor 38 described above is used.
In addition to the detection of the surface temperature of the pavement surface 12 by using, for example, as shown in FIG. 1, a snow sensor 42 for detecting the snow accumulation state of the pavement surface 12 is arranged at a position where the pavement surface 12 can be seen. The state of snow on the pavement surface 12 is set via the sensor 42 to information such as, for example, the color of the pavement surface 12 (by setting the ground color of the metal plate 14 to a color other than white, white when snow is accumulated). The power supply unit 36 supplies an alternating current from the power supply unit 36 to the induction coil 20 when there is snowfall, and the induction coil from the power supply unit 36 when no snowfall is detected. The supply of 20 alternating currents can be stopped. As the snow sensor 42, for example, a sensor using an infrared diffuse reflection type photoelectric element is known, but a configuration for detecting snow by another method (such as a method using a CCD camera) may be used. Further, a method of controlling the supply of the alternating current to the induction coil 20 using a snowfall sensor instead of the snowfall sensor 42 may be used.

In order to more efficiently supply the alternating magnetic field generated by the induction coil 20 to the metal plate 14, as shown in FIG. It is preferable to adopt a structure in which a core (for example, a core having an E-shaped or U-shaped cross section) 44 made of a magnetic material is put on the induction coil 20 thus formed. This makes it possible to reduce the magnetic flux leaking to the lower surface side of the metal plate 14 and increase the magnetic flux to the metal plate 14, thereby improving the heating efficiency of the metal plate 14 by the alternating magnetic field.

(Second Embodiment) The configuration of a snow melting pavement using induction heating according to the present embodiment is substantially the same as the configuration of the above-described first embodiment, and the different component is a metal plate. Instead of the body 14, a hollow metal box 46 made of a conductive material as shown in FIG. Then, the induction coil 20 has a structure to be laid close to the inner upper surface of the metal box 46. According to this,
Since the induction coil 20 is surrounded by the conductive material, the leakage magnetic flux is extremely reduced, and a snow melting pavement safer for the human body can be realized. In addition, since the induction coil 20 is configured to be disposed in the metal box 46, even if the induction coil 20 is laid close to the inner upper surface of the metal box 46, an external force from the pavement surface is not directly applied to the induction coil 20. Therefore, unlike the first embodiment, the induction coil 20 is not provided in the structure in which the flat winding 24 is embedded in the flat rubber body 22, that is, the induction coil 20 is formed only by the flat winding 24. Even if the structure becomes
The alternating magnetic field generated can be efficiently supplied to the pavement surface while preventing the induction coil 20 from being disconnected.

In FIG. 10, the two metal plates 14 described in the first embodiment are opposed to each other so that their legs 26 overlap each other, so that the opposite ends are opened. Although the metal box 46 is formed, the present invention is not limited to this.

When the snow melting pavement using induction heating according to the present invention is used, the object to be induction-heated by electromagnetic induction is not a fine powder like a conventional powder, but a metal plate having a larger area. Because it is a body, Joule heat generated inside increases, and efficient snow melting can be performed. Also,
Since it is not a structure in which a gap is formed between powder bodies as in the case of a powdery body, electromagnetic waves leaking to the outside of the pavement surface are reduced, and adverse effects on the living body can be reduced. Further, since the flat winding is buried in the rubber body, even if the flat winding is disposed close to the lower surface of the pavement surface, the external force received from the pavement surface is less likely to be damaged by the rubber body. And since it can be arrange | positioned close to the lower surface of a pavement surface, the alternating magnetic field which generate | occur | produces can be efficiently supplied to a pavement surface, and there exists an effect that efficient heating can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the structure of a snow melting pavement using induction heating according to the present invention.

FIG. 2 is a sectional view of the snow melting pavement using induction heating according to the first embodiment, taken along line WW in FIG. 1;

FIG. 3 is a perspective view for explaining a configuration of an induction coil.

FIG. 4 is a cross-sectional view for explaining a configuration of a flat winding constituting an induction coil.

FIG. 5 is a front view for explaining the configuration of another embodiment of the flat winding constituting the induction coil.

6A and 6B are diagrams for explaining the structure of the metal plate according to the first embodiment, wherein FIG. 6A is a side view, FIG.
(C) is a front view.

FIG. 7 is a front view showing the structure of another embodiment of the metal plate.

FIG. 8 is an explanatory diagram for explaining a method of fitting a fitting projection and a fitting recess when laying metal plate bodies side by side.

FIG. 9 is a perspective view for explaining an embodiment in which a core is placed on an induction coil in which a metal plate is arranged.

FIG. 10 is a perspective view illustrating a structure of a metal box used in the second embodiment.

FIG. 11 is an explanatory diagram for explaining a structure of a snow melting pavement using conventional induction heating.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Snow melting pavement 12 Pavement surface 14 Metal plate 16 Subgrade 20 Induction coil 22 Rubber body 24 Flat type winding

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tadashi Takahata 2-2-2, Yoyogi, Shibuya-ku, Tokyo East Japan Railway Company (72) Inventor Akira Sato 2-2-2, Yoyogi, Shibuya-ku, Tokyo No. Tohoku Nippon Passenger Railway Co., Ltd. (72) Inventor Tetsuzo Nichinada 168, Minami-Nagaike, Murano, Ono, Nagano City, Nagano Prefecture Inside Nichinada Electric Co., Ltd. 168 Muramae, Nichinada Electric Co., Ltd. (72) Inventor Masaaki Yanagisawa 168, Muranoe, Nagano, Nagano City, Nagano Prefecture F-term in Nichinada Electric Co., Ltd. 2D051 GA02 GB02 GB09 GC04

Claims (6)

[Claims] 1. A pavement surface formed by laying a metal plate made of a conductive material on a roadbed, and a flat coil formed by burying a flat winding in a flat rubber body. And an induction coil laid in close proximity to the lower surface of the pavement surface. 2. The induction heating according to claim 1, wherein the pavement surface is formed by laying a plurality of the metal plate members, and a joint portion between the metal plate members overlaps each other. Snow melting pavement used. 3. A lower portion of the metal plate body is provided with a leg portion for forming a space between a lower surface of the induction coil and the roadbed, and a heat insulating material is disposed in the space portion. The snow melting pavement using induction heating according to claim 1 or 2, wherein the snow melting pavement uses induction heating. 4. A pavement surface formed by laying a hollow metal box made of a conductive material on a roadbed, and an induction coil laid in close proximity to an inner upper surface of the metal box. Snow melting pavement using induction heating. A power supply unit for supplying an alternating current to the induction coil; a temperature sensor for measuring a surface temperature of the pavement surface; detecting the surface temperature via the temperature sensor; When the temperature becomes equal to or lower than the set first temperature, the supply of the alternating current from the power supply unit to the induction coil is started, and the detected surface temperature becomes the second temperature higher than the preset first temperature. 5. A snow melting pavement utilizing induction heating according to claim 1, further comprising a control unit for stopping supply of an alternating current from the power supply unit to the induction coil when the snow melting pavement reaches. 6. A power supply unit for supplying an alternating current to the induction coil; a snow sensor for detecting a snow condition on the pavement surface; and a snow condition on the pavement surface via the snow sensor.
5. A snow melting pavement using induction heating according to claim 1, further comprising: a control unit for supplying an alternating current from the power supply unit to the induction coil when snow is present.