JP6996705B2 - Radio wave type heat generator - Google Patents

Description

The present invention relates to a radio wave type heat generating device.

Conventionally, a radio wave type heat generating device including a leaky waveguide that guides a radio wave and a heat dissipation member that heats up and dissipates heat when the radio wave radiated from the leaky waveguide is incident is known. For example, in the radio wave type heat generating device described in Non-Patent Document 1, a slot for radiating radio waves to the heat radiating member is formed in the leakage waveguide, and this slot is in contact with the heat radiating member.

Yosuke Ito, Shinji Kawabe, Kei Ohba, "Study on Radio Shading Material for Heat-generating Mortar Block for Snowmelt by Semi-Microwave", Architectural Institute of Japan, Structural Papers, January 31, 2017, Vol. 82, No. 731, 1 -10 pages

According to the inventor's study, since the slot is in contact with the heat radiating member, the relative permittivity and / or the relative magnetic permeability of the heat radiating member have a great influence on the characteristics of radio wave radiation by the slot. Therefore, the radiating member is replaced with a radiating member having a different relative permittivity, or is replaced with a radiating member having a different relative permeability, or is replaced with a radiating member having a different relative permittivity and a different relative permittivity. Or, if the relative permittivity, the relative permeability, or both of the heat radiating member changes due to an external factor (for example, water cover), the characteristics of radio wave emission by the slot will change.

In view of the above points, in the present disclosure, in the radio wave type heat generating device, the heat radiating member is replaced with a radiating member having a different relative permittivity, or is replaced with a radiating member having a different relative permeability, or another relative permittivity. When the heat dissipation member is replaced with a rate and another relative permittivity, or when the relative permittivity and / or relative permeability of the heat dissipation member changes due to an external factor, the characteristics of radio wave emission by the slot are changed from the conventional one. Also aims to stabilize.

According to the first aspect of the present disclosure, the radio wave type heating device includes a leaky waveguide that guides a radio wave and a heat dissipation member that raises the temperature and dissipates heat when the radio wave radiated from the leaky waveguide is incident. And. The leakage waveguide is formed with one or more slots for radiating the radio waves to the heat dissipation member. At least a portion of the one or more slots is separated from the heat dissipation member.

In this way, at least a part of one or more slots is separated from the heat dissipation member. Therefore, the radiating member is replaced with a radiating member having a different relative permittivity, or is replaced with a radiating member having a different relative permeability, or is replaced with a radiating member having a different relative permittivity and a different relative permittivity. Or even if the relative permittivity and / or relative permeability of the heat dissipation member changes due to external factors, the change is unlikely to affect the characteristics of the radio radiation of the slot. Therefore, the characteristics of the radio wave radiation of the slot are more stable than before.

Further, according to the second aspect, the shortest distance from the one or more slots to the heat radiating member is 0.4 times or more the wavelength of the radio wave radiated from the one or more slots. If one or more slots are separated from the heat dissipation member by this degree, the stability of the radio wave emission characteristics of the one or more slots is further increased.

Further, according to the third viewpoint, when each of the one or more slots is set as the target slot, the shielding effect of the target slot is obtained by eliminating the heat radiating member from the radio wave type heat generating device. It is equivalent to the shielding effect of the target slot. As described above, if the radio wave shielding effect is the same with and without the heat dissipation member in each slot, the stability of the radio wave radiation characteristics of one or more slots is further increased.

Further, according to the fourth aspect, air is present in the gap between the one or more slots and the heat radiating member and in the internal space of the leak waveguide (12). Since the relative permittivity and the relative permeability of air are relatively stable, further stabilization of the characteristics of radio wave radiation is realized.

Further, according to the fifth aspect, the radio wave type heat generating device includes the leakage waveguide or the support member for supporting the heat radiating member so as to separate the heat radiating member from the one or more slots. By doing so, the leak-guided waveguide or the heat-dissipating member can be supported by the support member, and the distance between the one or more slots and the heating element can be set at an appropriate position.

Further, according to the sixth aspect, the one or more slots are a plurality of slots. The plurality of slots are arranged side by side along the propagation direction of the radio wave in the leakage waveguide. The plurality of slots include one or more first-class slots and one or more second-class slots. The one or more type 2 slots are arranged in the leakage waveguide on the side ahead of the one or more type 1 slots in the propagation direction of the radio wave.

In this way, most of the radio waves that did not leak in one or more type 1 slots are leaked in one or more type 2 slots. Therefore, the amount of reflected waves and standing waves generated in the leakage waveguide can be suppressed. As a result, the variation in the amount of microwave leakage in the direction of the microwave in the leakage waveguide can be suppressed.

Further, according to the seventh aspect, the radio wave type heating device includes a leak-guided tube that guides radio waves, a heat-dissipating member that raises the temperature and dissipates heat when the radio wave is incident, and the leak-guided tube or the heat-dissipating member. A support member for supporting the The leaky waveguide is formed with one or more slots for radiating the radio waves. The support member supports the leakage waveguide or the heat dissipation member so that at least a part of the one or more slots is separated from the heat dissipation member and radio waves are radiated from the slot to the heat dissipation member. It is a member of.

In this way, the support member may support the leak waveguide or the heat dissipation member so that at least a portion of the one or more slots is separated from the heat dissipation member. Therefore, the radiating member is replaced with a radiating member having a different relative permittivity, or is replaced with a radiating member having a different relative permeability, or is replaced with a radiating member having a different relative permittivity and a different relative permittivity. Or even if the relative permittivity and / or relative permeability of the heat dissipation member changes due to external factors, the change is unlikely to affect the characteristics of the radio radiation of the slot. Therefore, the characteristics of the radio wave radiation of the slot are more stable than before.

The reference numerals in parentheses in this column and in the claims indicate the correspondence between the terms described in the claims and the concrete objects described in the embodiments described later and which are examples of the terms. Is.

It is a perspective view which shows the whole block diagram of the snowmelting apparatus 1 which concerns on 1st Embodiment. It is a perspective view of the state in which a plurality of heat generation blocks 13 are removed from a snow melting device 1. It is a perspective view of one heat generation block 13. It is sectional drawing of the leakage waveguide 12 and the heat generation block 13. It is a perspective view of the snow melting device in an experimental environment. It is a figure which shows the heat generation state when the separation distance is 0 mm. It is a figure which shows the heat generation state when the separation distance is 50 mm. It is a graph which shows the relationship of the rising temperature with respect to the horizontal distance for each separation distance. It is a graph which shows the relationship of the rising temperature with respect to the separation distance for each horizontal distance. It is sectional drawing of the leakage waveguide 12 and the heat generation block 13 in the snowmelting apparatus which concerns on 2nd Embodiment. It is sectional drawing of the leakage waveguide 12 and the heat generation block 13 in the snowmelting apparatus which concerns on 3rd Embodiment. It is sectional drawing of the leakage waveguide 12 and the heat generation block 13 in the snowmelting apparatus which concerns on 4th Embodiment. It is a perspective view of the leakage waveguide 12 in 5th Embodiment.

(First Embodiment)
Hereinafter, the first embodiment will be described. The radio wave type snowmelting device 1 according to the present embodiment is a device installed on the road surface of a road, the ground of a garden of a private house, or the like, and converts radio waves into heat energy to melt snow in the vicinity of the snowmelting device 1. The snowmelting device 1 corresponds to a heat generating device.

As shown in FIGS. 1 and 2, the snowmelting device 1 has one radio wave oscillator 11, one leak waveguide 12, and a plurality of heat generating blocks 13. The whole of the plurality of heat generating blocks 13 constitutes one heat radiating member.

The radio wave oscillator 11 is a device that generates and outputs a radio wave having a predetermined frequency. As the predetermined frequency, for example, 2.45 GHz in the microwave band may be adopted, or a frequency in another radio band may be adopted.

The leakage waveguide 12 is a metal tube (for example, made of stainless steel, iron, brass, etc.) that guides the radio wave output by the radio wave oscillator 11. The radio wave output by the radio wave oscillator 11 is directed from one end (that is, the start end) in the longitudinal direction of the leakage waveguide 12 toward the other end (that is, the end) in the longitudinal direction of the leakage waveguide 12. Propagate along.

As shown in FIG. 2, on the upper surface of one side of the leaky waveguide 12, a rectangle surrounding a through hole penetrating from the internal space surrounded by the leaky waveguide 12 to the outer space of the leaky waveguide 12. A plurality of frame-shaped slots 121 are formed. Hereinafter, this upper surface is referred to as a slot forming surface 120.

The plurality of slots 121 are formed side by side in a row along the longitudinal direction of the leakage waveguide 12. The longitudinal direction of each slot 121 is orthogonal to the longitudinal direction of the leakage waveguide 12.

Each slot 121 functions as a slot antenna. That is, the radio wave propagating in the leakage waveguide 12 along the longitudinal direction is radiated from each slot 121 to the outside of the leakage waveguide 12.

Each of the plurality of heat generating blocks 13 is a plate-shaped member, and is arranged side by side in a row along the longitudinal direction of the leaked waveguide 12 on the slot forming surface 120 side of the leak waveguide 12. One side of the plate surface of the plurality of heat generating blocks 13 faces any one of the plurality of slots 121. The relative permittivity of each heat generation block 13 is different from the relative permittivity of water. Alternatively, the specific magnetic permeability of each heat generating block 13 is different from the specific magnetic permeability of water. Alternatively, both the relative permittivity and the relative magnetic permeability of each heat generating block 13 are different from the relative permittivity of water and the relative magnetic permeability of water.

Each of the plurality of slots 121 overlaps with any of the plurality of heat generating blocks 13 in a direction perpendicular to the opening surface of the plurality of slots 121 (that is, in the vertical direction). Then, from each slot 121, the radio wave after propagating through the leakage waveguide 12 is radiated toward the heat generation block 13 that vertically overlaps the slot 121. Therefore, most of the radio waves radiated from the plurality of slots 121 are incident on the plurality of heat generating blocks 13.

Air is present in the above-mentioned internal space of the leakage waveguide 12. That is, the above-mentioned internal space of the leakage waveguide 12 is filled with air.

As shown in FIG. 3, each of the plurality of heat generating blocks 13 is an integral body having a base material 131, a radio wave absorbing material 132, and a radio wave shielding material 133. Therefore, each heat generating block 13 is an integral body having at least a radio wave absorber 132. The substances other than the radio wave absorbing material 132 contained in each heat generating block 13 form an integral body together with the radio wave absorbing material 132.

The base material 131 is a member having a radio wave absorbing performance smaller than that of the radio wave absorbing material 132. The base material 131 transmits almost all the radio waves radiated from the slot 121 to the outside of the leakage waveguide 12. The base material may be, for example, hardened ordinary Portland cement mortar, other mortar, or a member other than the mortar (for example, concrete, asphalt, glass, resin plate, cloth, paper, etc.). May be.

The radio wave absorber 132 is a sheet-shaped member. Since the radio wave absorbing material 132 contains an iron oxide compound, the radio wave absorbing performance is much higher than that of the base material 131. The radio wave absorber 132 absorbs radio waves radiated from the slot 121 to the outside of the leakage waveguide 12 and generates heat. The radio wave absorber 132 may be manufactured using, for example, an electric furnace oxide slag having a particle size of 0.3 mm or less as an aggregate. As the radio wave absorber 132, electric furnace oxide slag containing an iron oxide compound, ferrite, carbon or the like may be used.

The radio wave shielding material 133 is a sheet-shaped member. The radio wave shielding material 133 reflects the radio wave radiated from the slot 121 to the outside of the leaked waveguide 12. As the radio wave shielding material 133, a material made of metal fibers such as a partially defective welded wire mesh or wire mesh, metal short fibers, or a metal plate may be used.

As shown in FIG. 3, the radio wave absorbing material 132 and the radio wave shielding material 133 are embedded in the base material 131. Therefore, the base material 131 functions as a housing that protects the radio wave absorbing material 132 and the radio wave shielding material 133 from the outside. However, the radio wave absorbing material 132 and the radio wave shielding material 133 do not necessarily have to be completely embedded in the base material 131, and a part of the heat generating block 13 is exposed on the side surface orthogonal to the surface of the leakage waveguide 12 side. May be.

Further, the radio wave absorber 132 is embedded in the heat generating block 13 on the side farther from the leakage waveguide 12 than the center in the vertical direction. By doing so, the heat generated by the radio wave absorber 132 is easily transferred to the surface of the heat generation block 13 opposite to the leakage waveguide 12.

Further, the radio wave shielding material 133 is arranged on the opposite side of the leakage waveguide 12 with respect to the radio wave absorbing material 132 together with a part of the base material 131. Most of the base material 131 is arranged between the radio wave absorber 132 and the leakage waveguide 12. Since the heat generation block 13 has such a structure, the temperature rises due to the incident of radio waves and heat is dissipated to the surroundings.

When the radio wave oscillator 11 outputs a radio wave, the radio wave travels in the leaky waveguide 12 along the longitudinal direction of the leaky waveguide 12 and is radiated from the plurality of slots 121 toward the plurality of heat generation blocks 13. The radio wave radiated toward the heat generation block 13 passes through the base material 131, and a part of the radio wave is absorbed by the radio wave absorber 132. The radio wave transmitted through the radio wave absorbing material 132 without being absorbed by the radio wave absorbing material 132 is reflected by the radio wave shielding material 133 and then absorbed by the radio wave absorbing material 132.

When the radio wave absorber 132 absorbs radio waves, it converts the energy of the absorbed radio waves into heat energy and generates heat. The heat generated in this way is transferred from the radio wave absorbing material 132 to the base material 131 and the radio wave shielding material 133 by heat conduction, and as a result, the temperature of the entire surface of the heat generating block 13 rises.

The amount of temperature rise on the upper surface of the heat generation block 13 is larger than the amount of temperature rise on other surfaces. This is because, as described above, the radio wave absorber 132 is located above the center of the heat generating block 13 in the vertical direction. When the temperature of the upper surface of the heat generating block 13 rises, the snow accumulated on the upper surface melts.

FIG. 4 describes a method of installing the leakage waveguide 12 and the heat generation block 13. The leakage waveguide 12 is placed on the upper surface of the base portion 20. The base portion 20 may be, for example, soil, asphalt, or river sand spread in a concrete U-shaped gutter.

Further, at both ends of the leak waveguide 12 in the lateral direction on the slot forming surface 120, the lower ends of the wooden rod-shaped support member 14 are located in the longitudinal direction of the leak waveguide 12. Multiple lines are fixed along the line. The lateral direction of the leak-guided waveguide 12 is a direction orthogonal to both the longitudinal direction and the vertical direction of the leak-guided waveguide 12.

These support members 14 extend in a direction perpendicular to the opening surfaces of the plurality of slots 121 (that is, in the vertical direction). The lower end of the heat generation block 13 is fixed to the upper end of these support members 14. Since each support member 14 is made of wood, that is, a non-conductive dielectric, it is difficult to reflect radio waves leaked from the leak-guided waveguide 12. Further, the support member 14 is arranged at a position on the slot forming surface 120 where the shortest distance to the adjacent slots 121 is the longest so that the radio wave leaked from the leakage waveguide 12 is less likely to be reflected by the support member 14. ing.

Each support member 14 supports the corresponding heat generation block 13 by urging the corresponding heat generation block 13 in a direction away from the slot 121 of the leakage waveguide 12. That is, each support member 14 urges the corresponding heat generation block 13 in the direction in which radio waves are radiated from the slot 121.

At this time, the end portion of each heat generating block 13 in the lateral direction of the leakage waveguide 12 is supported by the corresponding support member 14, but the central portion of each heat generating block 13 in the lateral direction is not supported. Is. Therefore, the heat generation block 13 may bend due to its own weight. In the present embodiment, even if there is such a risk, the slot 121 is intentionally separated from the heat generation block 13. This is because the effect that the slot 121 is separated from the heat generation block 13 is important.

Of the slot forming surfaces 120 of the leakage waveguide 12, the slot forming surface 120 on which the slot 121 is formed and faces the heat generation block 13 is separated from the heat generation block 13 by such a plurality of support members 14. There is. Therefore, all the slots 121 formed on the slot forming surface 120 are separated from the heat generating block 13.

That is, a gap is provided between each slot 121 and the heat generating block 13. It should be noted that the portion of the leakage waveguide 12 other than the slot forming surface 120 is naturally separated from the heat generating block 13 by the same as or more than the slot forming surface 120.

Further, in this case, air and the support member 14 are present in the gap between the slot forming surface 120 and the heat generating block 13. That is, the gap between the slot forming surface 120 and the heat generating block 13 is filled with air and a plurality of support members 14. Further, only air exists in the gap between each slot 121 and the heat generating block 13. That is, the gap between each slot 121 and the heat generating block 13 is filled with air.

More specifically, assuming that each of the plurality of slots 121 is the target slot 121, the shortest distance from the target slot 121 to the plurality of heat generation blocks 13 is obtained by multiplying the wavelength of the radio wave emitted from the target slot 121 by 0.4. Is above the value. Therefore, the shortest distance from the entire leakage waveguide 12 to the heat generation block 13 is also equal to or greater than the value obtained by multiplying the wavelength of the radio wave emitted from the slot 121 by 0.4. Practically, a remarkable effect is produced even if the wavelength of the radio wave is multiplied by 0.4 or more, but if the value is multiplied by 0.5 or more, the effect is still higher.

By doing so, even if the relative permittivity and / or the relative permeability of the heat generation block 13 change significantly due to the adhesion of water (that is, the water cover), the radiation characteristics of the leakage waveguide 12 are almost affected. Does not appear. Further, air has a more stable relative permittivity and relative magnetic permeability than the heat generating block 13. Therefore, even if there is air near the slot 121, it is unlikely that the radiation characteristics of the leakage waveguide 12 will be adversely affected. Further, when a gap is interposed between the slot forming surface 120 and the heat generation block 13, it is easy to insert a radio wave measuring device into the gap and test the radiation characteristics of the leak waveguide 12.

Hereinafter, the results of heat generation experiments conducted by the inventor on a plurality of types of snowmelting devices 1 satisfying the above characteristics will be shown.

The details of the snowmelting device 1 used in the experiment will be described below. The radio wave oscillator 11 is a magnetron, the output is 1100 W or more and 1200 W or less, and the frequency of the radio wave to be output is 2.45 GHz. Further, the terminal portion of the leakage waveguide 12 in the longitudinal direction is short-circuited by the reflector.

Further, the width of each of the plurality of slots 121 is uniformly 3 mm. Further, the length of each of the plurality of slots 121 is uniformly 30 mm. The distance between two adjacent slots 121 is uniformly 10 mm. The leakage waveguide 12 is made of stainless steel metal. Here, the width of each slot 121 is the width of the slot 121 along the longitudinal direction of the leakage waveguide 12. The length of each slot 121 is the length of the slot 121 along the lateral direction of the leakage waveguide 12.

Further, each of the plurality of heat generating blocks 13 is a square plate having a length of 300 mm, a width of 300 m, and a thickness of 45 mm. The thickness of the radio wave absorber 132 is 8 mm. Further, the thickness of the base material 131 on the side closer to the leakage waveguide 12 than the radio wave absorber 132 is 29 mm. Further, the thickness of the portion made of the base material 131 and the radio wave shielding material 133 on the side farther from the leakage waveguide 12 than the radio wave absorbing material 132 is 8 mm. The number of the plurality of heat generating blocks 13 is eight, and the total length is 2.4 m by arranging them in a line along the longitudinal direction of the leakage waveguide 12.

Here, in the experiment, the shortest distance (hereinafter referred to as a separation distance) from each of the plurality of slots 121 to the plurality of heat generation blocks 13 is changed to 0 mm, 5 mm, ..., 70 mm, and from 0 mm to 70 mm in 5 mm increments, for a total of 15. Kind of experiment was done. In each experiment, the distance from each of the plurality of slots 121 to the heat generation block 13 is the same in all the slots 121.

FIG. 5 shows a photograph of the snowmelting device 1 used in the experiment. 6 and 7 show thermography when the radio wave oscillator 11 continuously outputs radio waves for 30 minutes in an experiment with a separation distance of 0 mm and 50 mm, respectively. When the separation distance is 0 mm, the plurality of heat generating blocks 13 that are closer to the radio wave oscillator 11 have a larger amount of heat generation. On the other hand, when the separation distance is 50 mm, the plurality of heat generating blocks 13 are warmed almost uniformly regardless of the distance from the radio wave oscillator 11.

FIG. 8 shows the rising temperature in the central portion of each heat generating block 13 when the radio wave oscillator 11 continuously outputs radio waves for 30 minutes, and the leaked waveguide 12 from the start end of the leaky waveguide 12 to the rising temperature measurement position. The relationship with the distance along the longitudinal direction (that is, the horizontal distance) is shown every 10 mm from the separation distance of 0 mm to 70 mm.

When the separation distance is 0 mm, there is a difference of about 60 ° C. between the high temperature portion and the low temperature portion. It is considered that this is because the relative permittivity and / or the relative permeability of the heat generation block 13 affect the amount of radio waves leaked (that is, the amount of radio waves radiated) in the slot of the leaked waveguide 12.

In such a radio wave leakage state, if the length of the leakage waveguide 12 and the heat dissipation member in the longitudinal direction is extended (for example, up to 10 m) from the snow melting device 1 used in the experiment, the starting end portion of the leakage waveguide 12 is obtained. At a portion closer to the termination portion than the center of the termination portion, almost no radio wave is output from the slot 121. Therefore, it is desirable that the amount of radio waves leaked in the leaked waveguide 12 is as uniform as possible regardless of the distance from the starting end.

On the other hand, when the separation distance is 20 mm or more, the variation in the rising temperature among the plurality of heat generating blocks 13 is reduced as compared with the case where the separation distance is 0 mm. That is, if a gap is provided between the heat generation block 13 and each slot 121, each slot 121 is less likely to be affected by the relative permittivity, the relative magnetic permeability, or both of the heat generation block 13. Within the range of this measurement, when the separation distance is 20 mm or more, the amount of radio wave leakage can be made substantially uniform over the length direction of the leakage waveguide 12.

FIG. 9 shows the relationship of the separation distance with respect to the rising temperature in the central portion of each heat generating block 13 when the radio wave oscillator 11 continuously outputs radio waves for 30 minutes. When the separation distance is 50 mm or more, there is almost no change in the rising temperature even if the separation distance is further increased. That is, if a gap of 0.4 × λ or more is provided between the heat generation block 13 and each slot 121, each slot 121 is hardly affected by the relative permittivity of the heat generation block 13 or the relative magnetic permeability of the heat generation block 13. It is hardly affected by the above, or it is hardly affected by the relative permittivity and the relative permeability of the heat generation block 13. Here, λ is the wavelength of the radio wave radiated from each slot 121.

Further, there is almost no attenuation of radio waves in the gap between the heat generation block 13 and the leakage waveguide 12. This is because if there is attenuation in the gap between the heat generation block 13 and the leakage waveguide 12, the rising temperature drops endlessly as the gap is increased.

From the above, if the snow melting device 1 is constructed with a gap of 0.4 × λ or more provided between the plurality of heat generation blocks 13 and the leakage waveguide, each slot 121 of the leakage waveguide 12 will have a plurality of slots 121. It is hardly affected by the relative permittivity of the heat generating block 13, is hardly affected by the relative magnetic permeability of the heat generating block 13, or is hardly affected by the relative permittivity and the relative magnetic permeability of the heat generating block 13.

When the separation distance is 0.4 × λ or more, the influence of the plurality of heat generation blocks 13 on the shielding effect of each slot 121 is almost eliminated. That is, when each of the plurality of slots 121 is set as the target slot, the shielding effect of the target slot is the shielding effect of the target slot in the product obtained by eliminating all the heat generating blocks 13 from the snowmelting device 1 as shown in FIG. Is equivalent to. Here, "equivalent" means that the difference is 1 dB or less. As described above, if the radio wave shielding effect is the same with and without the heat dissipation member in each slot 121, the stability of the radio wave radiation characteristics of the slot 121 is further increased.

By doing so, it is possible to uniformly heat the plurality of heat generating blocks 13 over the longitudinal direction of the leakage waveguide 12.

The relationship between the influence of the plurality of heat generation blocks 13 on each slot 121 and the separation distance depends on the shape of the leakage waveguide 12 and the size of the leakage waveguide 12 of the heat generation block 13. It hardly depends on the shape or the size of the heat generating block 13. Further, it is presumed that the degree of influence of the relative permittivity of each heat generation block 13 on the relationship between the influence of the plurality of heat generation blocks 13 on each slot 121 and the separation distance is small. Alternatively, it is presumed that the degree of influence of the relative magnetic permeability of each heat generation block 13 on the relationship between the influence of the plurality of heat generation blocks 13 on each slot 121 and the separation distance is small. Alternatively, it is presumed that the degree of influence of both the relative permittivity and the relative magnetic permeability of each heat generation block 13 on the relationship between the influence of the plurality of heat generation blocks 13 on each slot 121 and the separation distance is small. To.

The experimental results shown in FIGS. 8 and 9 show that when the plurality of heat generating blocks 13 are separated from the plurality of slots 121, the amount of radio wave leakage can be substantially uniform in the longitudinal direction of the leaked waveguide 12. It is shown that.

However, this experiment does not show that when a plurality of heat generating blocks 13 come into contact with a plurality of slots 121, the amount of radio wave leakage cannot be substantially uniform in the longitudinal direction of the leaked waveguide 12. do not have. If the length and width of the plurality of slots 121 are appropriately adjusted, even if each slot 121 is in contact with any of the plurality of heat generation blocks 13, the amount of radio wave leakage is approximately one in the longitudinal direction of the leakage waveguide 12. Can be like.

However, since the relative permittivity, the relative magnetic permeability, or both of the heat generation block 13 greatly changes depending on the water cover or the like, the uniformity of the amount of radio wave leakage is greatly impaired by the water cover or the like of the heat generation block 13. There is a fear.

On the other hand, if each slot 121 is separated from the plurality of heat generation blocks 13, the influence of the plurality of heat generation blocks 13 on each slot 121 of the relative permittivity, the relative magnetic permeability, or both of them can be suppressed. Therefore, even if the relative permittivity, the relative magnetic permeability, or both of the heat generation block 13 changes due to water exposure or the like, the possibility that the uniformity of the amount of radio wave leakage is impaired is reduced.

Therefore, even if the relative permittivity, the relative magnetic permeability, or both of the heat radiating member changes due to the water exposure of the heat radiating member, the change is unlikely to affect the radio wave radiation characteristics of each slot 121. Therefore, the characteristics of the radio wave radiation of each slot 121 are more stable than before with respect to the water covered by the heat radiating member.

Here, the influence of the relative permittivity, the relative magnetic permeability, or both of the plurality of heat generating blocks 13 on each slot 121 will be described. When the length of each slot 121 is close to the half wavelength of the radio wave, a large amount of radio waves are leaked, but when each slot 121 leaks too much radio waves, a sufficient amount is reached near the end of the leaked waveguide 12. Radio waves will not reach.

Therefore, in the present embodiment, the length of the slot 121 is set so that the radio wave is evenly leaked to the vicinity of the terminal portion. However, the length of the half wavelength of the radio wave is "wavelength in air / (ε ^1/2 x μ ^1/2 )" when the relative permittivity and relative permeability of the environment around the slot 121 are ε and μ, respectively. )"become. Since the ε around the slot 121 is increased by bringing the heat generation block 13 closer to the slot 121, the wavelength of the radio wave is changed by bringing the heat generation block 13 closer to the slot 121. In this case, if the design does not take such a change into consideration, uniform radio waves cannot be emitted in the longitudinal direction of the leakage waveguide 12. Further, in this case, since there is no gap between the heat generation block 13 and the leakage waveguide 12, it is difficult to directly measure the amount of radio wave leakage from the leakage waveguide 12 with a measuring device, and it is difficult to design in consideration of the above changes. Is.

In this way, since one or more slots are separated from the heat radiating member, the radiating member is replaced with a radiating member having a different relative permittivity, or is replaced with a radiating member having a different relative permeability, or another. Even if the relative permittivity and / or relative permittivity of the heat dissipation member change due to external factors, the change is the radio wave of the slot. It does not easily affect the characteristics of radiation. Therefore, the characteristics of the radio wave radiation of the slot are more stable than before.

Further, the data designed by directly measuring the radio wave leakage amount of the leakage waveguide 12 in the state where the heat generation block 13 is not installed is used as the radio wave leakage amount of the leakage waveguide 12 after the heat generation block 13 is installed. It can be utilized.

Further, since the relative permittivity and the relative magnetic permeability of the air interposed between each slot 121 and the plurality of heat generating blocks 13 are relatively stable, the uniformity of the amount of radio wave leakage may be further impaired. It will be reduced. That is, further stabilization of the radio wave radiation characteristics of each slot 121 is realized.

(Second Embodiment)
Next, the second embodiment will be described with reference to FIG. The snowmelt device 1 of the present embodiment has a different support structure between the leakage waveguide 12 and the heat generation block 13 as compared with the snowmelt device 1 of the first embodiment.

Specifically, the snowmelting device 1 of the present embodiment has a plurality of support members 15a and a plurality of support members 15b instead of the plurality of support members 14. The plurality of support members 15a and the plurality of support members 15b are deformable string-shaped members.

The upper end of each of the plurality of support members 15a is fixed to the lower end and the side end of the heat generation block 13, and the lower end is fixed to the upper end and the side end of the leakage waveguide 12. The upper end of each of the plurality of support members 15b is fixed to the lower end and the side end of the heat generation block 13, and the lower end is fixed to the lower end and the side end of the leakage waveguide 12. The side end is the end of the leakage waveguide 12 in the lateral direction.

The plurality of heat generating blocks 13 are supported by an upper end portion of a U-shaped gutter (not shown) and arranged so as to close the U-shaped gutter. The U-shaped gutter supports the heat generation block 13 by urging the heat generation block 13 in a direction away from the slot 121 of the leakage waveguide 12. That is, the U-shaped gutter urges the heat generation block 13 in the direction in which radio waves are radiated from the slot 121. At this time, the end portion of each heat generating block 13 in the lateral direction of the leakage waveguide 12 is supported by the U-shaped gutter, but the central portion of each heat generating block 13 in the lateral direction is not supported. ..

The leakage waveguide 12 is suspended inside the U-shaped gutter by the support members 15a and 15b. That is, the leakage waveguide 12 is supported by these support members 15a and 15b.

The plurality of support members 15a and 15b are tilted with respect to the vertical direction in a stable state in which the leakage waveguide 12 is suspended. In this way, the support member 14 is stably supported.

Each of the support members 15a and 15b is a non-conductive dielectric such as cloth. Therefore, the degree of influence of the support members 15a and 15b on the electrical characteristics of the leakage waveguide 12 is low. In the state where the leakage waveguide 12 is supported in a form suspended from above, for example, even if the U-shaped gutter is too deep, the separation distance between the leakage waveguide 12 and the plurality of heat generation blocks 13 Can be kept properly.

Then, by appropriately adjusting the lengths of the support members 15a and 15b, the distances from each slot 121 to the plurality of heat generating blocks 13 can be appropriately adjusted. The separation distance from each slot 121 to the plurality of heat generating blocks 13 is the same as in the first embodiment.

(Third Embodiment)
Next, the third embodiment will be described with reference to FIG. The snowmelt device 1 of the present embodiment has a different support structure between the leakage waveguide 12 and the heat generation block 13 as compared with the snowmelt device 1 of the first embodiment.

Specifically, the snowmelting device 1 of the present embodiment has a plurality of support members 16 instead of the plurality of support members 14. These plurality of support members 16 are deformable string-shaped members.

The upper end of each of the plurality of support members 16 is fixed to the lower end and the side end of the heat generation block 13, and the lower end is fixed to the upper end and the side end of the leakage waveguide 12. The side end is the end of the leakage waveguide 12 in the lateral direction.

The plurality of heat generating blocks 13 are supported by an upper end portion of a U-shaped gutter (not shown). The U-shaped gutter supports the heat generation block 13 by urging the heat generation block 13 in a direction away from the slot 121 of the leakage waveguide 12. That is, the U-shaped gutter urges the heat generation block 13 in the direction in which radio waves are radiated from the slot 121. At this time, the end portion of each heat generating block 13 in the lateral direction of the leakage waveguide 12 is supported by the U-shaped gutter, but the central portion of each heat generating block 13 in the lateral direction is not supported. ..

The leakage waveguide 12 is suspended inside a U-shaped gutter by a support member 16. That is, the leakage waveguide 12 is supported by these support members 16. These plurality of support members 16 extend in parallel in the vertical direction in a stable state in which the leakage waveguide 12 is suspended.

Each of the support members 16 is a non-conductive dielectric such as cloth. Therefore, the degree of influence of the support member 16 on the electrical characteristics of the leakage waveguide 12 is low. In the state where the leakage waveguide 12 is supported in a form suspended from above, for example, even if the U-shaped gutter is too deep, the separation distance between the leakage waveguide 12 and the plurality of heat generation blocks 13 Can be kept properly.

Then, by appropriately adjusting the lengths of these support members 16, the separation distance from each slot 121 to the plurality of heat generating blocks 13 can be appropriately adjusted. The separation distance from each slot 121 to the plurality of heat generating blocks 13 is the same as in the first embodiment.

(Fourth Embodiment)
Next, the fourth embodiment will be described with reference to FIG. The snowmelt device 1 of the present embodiment has a different support structure between the leakage waveguide 12 and the heat generation block 13 as compared with the snowmelt device 1 of the first embodiment.

In the present embodiment, the base 17 for height adjustment is placed on the bottom of the U-shaped gutter 21. Then, the leakage waveguide 12 is placed on the upper surface of the base 17. As a result, the leakage waveguide 12 is arranged in the U-shaped gutter 21. The heat generating block 13 is placed on the upper end of the U-shaped gutter 21 and is arranged so as to close the U-shaped gutter 21. The U-shaped gutter 21 supports the heat generation block 13 by urging the heat generation block 13 in a direction away from the slot 121 of the leakage waveguide 12. That is, the U-shaped gutter 21 urges the heat generating block 13 in the direction in which radio waves are radiated from the slot 121. At this time, the end of each heat generating block 13 in the lateral direction of the leakage waveguide 12 is supported by the U-shaped gutter 21, but the central portion of each heat generating block 13 in the lateral direction is not supported. be.

By appropriately adjusting the height of the base 17 in the vertical direction, the separation distance from each slot 121 to the plurality of heat generating blocks 13 can be appropriately adjusted. The separation distance from each slot 121 to the plurality of heat generating blocks 13 is the same as in the first embodiment.

(Fifth Embodiment)
Next, the fifth embodiment will be described with reference to FIG. In the first to fourth embodiments, the plurality of slots 121 formed on the slot forming surface 120 and overlapping with any of the plurality of heat generating blocks 13 in the vertical direction have the same width and length.

On the other hand, in the present embodiment, a plurality of the plurality of slots 121 are replaced with the plurality of slots 122 as shown in FIG. The replacement is done on a one-to-one basis. Each of the plurality of slots 122, like each slot 121, is a rectangular frame-shaped slot surrounding a through hole penetrating from the internal space surrounded by the leak waveguide 12 to the external space of the leak waveguide 12.

Further, the shortest distance (that is, the separation distance) from each of the plurality of slots 122 to the plurality of heat generation blocks 13 is also the same as the shortest distance from each of the two or more slots 121 to the plurality of heat generation blocks 13.

Each of the plurality of slots 122 has a larger length in the lateral direction in the leakage waveguide 12 than any of the plurality of slots 121. For example, each of the plurality of slots 122 may have a length in the lateral direction of the leakage waveguide 12 that is twice or more that of each of the plurality of slots 121. Further, in each of the plurality of slots 122, the length of the leaky waveguide 12 in the lateral direction is 0.9 times or more and 1.1 times or less the half wavelength of the radio wave propagating through the leakage waveguide 12. You may.

By doing so, each of the plurality of slots 122 has a larger amount of radio wave leakage than any of the remaining two or more slots 121.

Further, in this way, the two or more slots 121 and the plurality of slots 122 are arranged in a continuous line along the propagation direction of the radio wave in the leakage waveguide 12 as a whole. ..

Each of the plurality of slots 121 corresponds to a type 1 slot, and each of the plurality of slots 122 corresponds to a type 2 slot.

Then, these two or more slots 121 are arranged side by side continuously (that is, without sandwiching the slot 122 between them) along the propagation direction of the radio wave in the leakage waveguide 12. Further, the plurality of slots 122 are arranged side by side continuously (that is, without sandwiching the slot 121 between them) in the leakage waveguide 12 on the side ahead of the two or more slots 121 in the propagation direction of the radio wave. Has been done. The front side is the terminal side of the leakage waveguide 12.

In this way, most of the radio waves that did not leak in the two or more slots 121 are leaked in the plurality of slots 122. Therefore, the amount of the reflected wave generated by the reflection of the radio wave at the terminal portion of the leakage waveguide 12 is suppressed, and the standing wave is less likely to be generated. As a result, the variation in the amount of radio wave leakage in the longitudinal direction of the leakage waveguide 12 (that is, the radio wave propagation direction) is further suppressed.

It should be noted that each of the two or more slots 121 and the plurality of slots 122 is formed on the slot forming surface 120 and overlaps with any of the plurality of heat generating blocks 13 in the vertical direction. By doing so, the leakage of unnecessary radio waves that do not contribute to the generation of heat in the heat radiating member is reduced.

The width of each of the plurality of slots 122 may be the same as or different from the width of the two or more slots 121.

(Other embodiments)
The present invention is not limited to the above-described embodiment, and can be appropriately modified. Further, the above embodiments are not unrelated to each other, and can be appropriately combined unless the combination is clearly impossible. Further, in each of the above embodiments, the elements constituting the embodiment are not necessarily essential except when it is clearly stated that they are essential or when they are clearly considered to be essential in principle. Further, in each of the above embodiments, when numerical values such as the number, numerical values, quantities, and ranges of the constituent elements of the embodiment are mentioned, when it is clearly stated that they are particularly essential, and when it is clearly limited to a specific number in principle. It is not limited to the specific number except when it is done. In particular, when a plurality of values are exemplified for a certain amount, it is also possible to adopt a value between the plurality of values unless otherwise specified or when it is clearly impossible in principle. .. Further, in each of the above embodiments, when the shape, positional relationship, etc. of the constituent elements are referred to, the shape, unless otherwise specified or limited in principle to a specific shape, positional relationship, etc. It is not limited to the positional relationship. Further, the present invention also allows the following modifications and equal range modifications for each of the above embodiments. It should be noted that the following modifications can be independently selected to be applied or not applied to the above embodiment. That is, any combination of the following modifications can be applied to the above embodiment.

(Modification 1)
In each of the above embodiments, the space between each slot 121 and the heat generating block 13 vertically above the slot 121 is filled with air. However, this does not necessarily have to be the case. For example, the space between each slot 121 and the heat radiating member may be filled with a vacuum. In that case, the internal space of the leakage waveguide 12 may also be filled with a vacuum.

Alternatively, a dielectric having a predetermined relative permittivity and relative permeability may be arranged between each slot 121 and the heat radiating member instead of air. In that case, the same dielectric may be arranged in the internal space of the leakage waveguide 12.

(Modification 2)
In each of the above embodiments, the radio wave output from the radio wave oscillator 11 and absorbed by the radio wave absorber 132 through the leakage waveguide 12 is a radio wave. However, the radio wave output from the radio wave oscillator 11 and absorbed by the radio wave absorber 132 through the leakage waveguide 12 may be a radio wave other than the radio wave.

(Modification 3)
In each of the above embodiments, the longitudinal direction of the slots 121 and 122 is parallel to the lateral direction of the leakage waveguide 12. However, the longitudinal direction of the slots 121 and 122 may be parallel to the longitudinal direction of the leaky waveguide 12, or parallel to the direction intersecting both the longitudinal direction and the lateral direction of the leakage waveguide 12. May be.

(Modification example 4)
In the above embodiment, the separation distance of each slot is equal to or greater than the value obtained by multiplying the wavelength of the radio wave mainly emitted from the slot by 0.4. However, the separation distance of each slot may be less than the value obtained by multiplying the wavelength of the radio wave mainly emitted from the slot by 0.4 and greater than zero. Even if this is the case, it is less likely to be affected by changes in the relative permittivity, changes in the relative permeability, or both due to water exposure of the plurality of heat generating blocks 13 as compared with the case where the separation distance is zero.

(Modification 5)
In the above embodiment, the separation distances of all the slots 121 and 122 are the same, but this is not always the case. The separation distances may be different from each other in the plurality of slots 121.

(Modification 6)
In each of the above embodiments, all of the slots 121 are separated from the heat generation block 13. However, this does not necessarily have to be the case. Of the plurality of slots 121, only a part of the slots 121 may be separated from the plurality of heat generation blocks 13, and the other slots 121 may be in contact with any of the heat generation blocks 13. The number of slots separated from the plurality of heat generation blocks 13 may be only one or may be plural.

(Modification 7)
In the fifth embodiment, the leakage waveguide 12 is formed with a plurality of slots 121 and a plurality of slots 122. However, only a plurality of slots 121 and one slot 122 may be formed in the leakage waveguide 12.

(Modification 8)
Further, in the fifth embodiment, the slot 122 is the slot closest to the terminal portion in the leakage waveguide 12. However, a slot having the same length as the slot 121 may be further arranged on the front side (that is, the terminal side of the leakage waveguide 12) with respect to the slot 122.

(Modification 9)
Further, in the fifth embodiment, the entire slot 122 overlaps with any of the plurality of heat generating blocks 13 in the vertical direction. However, only a part of the slot 122 may vertically overlap with any of the plurality of heat generating blocks 13. Alternatively, all the slots 122 may be arranged so as not to vertically overlap any of the plurality of heat generating blocks 13.

(Modification 10)
In each of the above embodiments, the snow melting device 1 is disclosed as an example of the radio wave type heat generating device. However, the application of the radio wave type heat generating device is not limited to snow melting. The radio wave type heat generating device may be used for any purpose as long as the heat generating block 13 may be exposed to water.

1 ... Snow melting device, 11 ... Radio oscillator, 12 ... Leakage waveguide, 13 ... Heat generation block, 14, 15a, 15b, 16, 17 ... Support member, 20 ... Base part, 21 ... U-shaped gutter, 121, 122 ... Slot, 131 ... base material, 132 ... radio wave absorber, 133 ... radio wave shielding material

Claims (7)

Leakage waveguide (12) that guides radio waves,
A heat radiating member (13) that raises the temperature and dissipates heat when the radio wave radiated from the leaking waveguide is incident is provided.
The leak-guided tube (12) is formed with one or more slots (121, 122) that radiate the radio waves to the heat dissipation member.
At least a part of the one or more slots (121) is separated from the heat radiating member (13) , and the gap provided between the one or more slots and the heat radiating member is the heat radiating member (13). A radio wave type heat generating device characterized in that the relative permittivity or the relative magnetic permeability is stable as compared with the above . The shortest distance from the one or more slots (121, 122) to the heat radiating member (13) is 0.4 times or more the wavelength of the radio wave radiated from the one or more slots (121, 122). The radio wave type heat generating device according to claim 1. When each of the one or more slots is a target slot, the shielding effect of the target slot is the shielding effect of the target slot in the product obtained by eliminating the heat radiating member (13) from the radio wave type heat generating device. , The radio wave type heat generating device according to claim 1 or 2, characterized in that they are equivalent. 1. The radio wave type heating device according to any one of 3. A support member (14, 15a, 15b, 16, 17) for supporting the leakage waveguide (12) or the heat radiating member (13) is provided so as to separate the heat radiating member (13) from the one or more slots. The radio wave type heat generating device according to any one of claims 1 to 4, characterized in that. The one or more slots are a plurality of slots (121, 122).
The plurality of slots (121, 122) are arranged side by side along the propagation direction of the radio wave in the leakage waveguide (12).
The plurality of slots include one or more first-class slots (121) and one or more second-class slots (122) .
Each of the one or more Type 2 slots (122) has a greater length in the lateral direction in the leak waveguide (12) than any of the one or more Type 1 slots. The lateral direction is a direction orthogonal to both the propagation direction and the vertical direction.
The one or more type 2 slots (122) are arranged in the leakage waveguide (12) ahead of the one or more type 1 slots in the propagation direction of the radio wave. The radio wave type heat generating device according to any one of claims 1 to 4, wherein the radio wave type heating device is characterized. Leakage waveguide (12) that guides radio waves,
A heat radiating member (13) that absorbs radio waves and generates heat,
The leaky waveguide (12) is provided with a support member (14, 15a, 15b, 16, 17) for supporting the leaky waveguide (12) or the heat dissipation member ( 13 ), and the radio wave is provided in the leaky waveguide (12). One or more slots (121) are formed to radiate
In the support member (14, 15a, 15b, 16, 17), at least a part of the one or more slots (121) is separated from the heat radiating member (13), and radio waves are transmitted from the slot to the heat radiating member (13). Is a member for supporting the leakage waveguide (12) or the heat dissipation member (13) so that the radiation may be emitted .
A radio wave type heat generating device characterized in that a gap provided between the one or more slots and the heat radiating member has a stable relative permittivity or relative magnetic permeability as compared with the heat radiating member (13) .

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