JPS6126194B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an open-type high-frequency irradiation device used to irradiate radio waves in a high-frequency range onto an irradiated object to, for example, heat, sterilize, or kill insects. be.

[Conventional technology]

Conventionally, heating, sterilization, insecticide, etc. by irradiating radio waves in the high frequency range to an irradiated object has been used, for example, to heat and melt asphalt pavement, to kill plants, insects, bacteria, etc. in the soil, to kill insects, etc. There are examples where it has been used for sterilization, etc., and it is already known that irradiation with a high-frequency irradiation device is effective in that case.

The advantage of high-frequency irradiation equipment over other methods such as infrared rays, hot air, and steam is that it can heat, sterilize, and kill insects not only on the surface of asphalt-paved roads and soil slabs, but also on the inside of them in a short time. For example, if you want to raise the temperature of an asphalt pavement 10cm deep by 50℃ without burning out the surface using infrared rays, etc., it will take several hours, but 2450MHZ;
When microwaves of 10 W/cm ² are used, the temperature can be raised within a few minutes, and thus microwave irradiation shortens the processing time to 1/100 or less.

[Problem that the invention seeks to solve]

When irradiating radio waves in the high frequency range to an irradiated object, an applicator such as a waveguide open end, a horn, or a cone is used, but the radio waves radiated from such an applicator are It usually undergoes exponential attenuation due to the spread of the beam and loss of the irradiated object. For example, if the object to be irradiated is a transparent material with low loss for high-frequency radio waves, it is difficult to concentrate the high-frequency radio waves only on the areas of the object where effects such as heating, sterilization, or insecticidal effects are expected. However, the high-frequency radio waves dissipate and the leakage power becomes essentially ineffective, resulting in a large amount of leakage power, and the irradiation efficiency, even heating, sterilization, and insecticidal efficiency, decreases. For example, in asphalt-paved roads and soils with low moisture content, the imaginary part of the complex permittivity that determines the loss of high-frequency radio waves is less than 0.1, and the penetration depth of the high-frequency radio waves is 1 m or more, meaning that they are simply exposed to high-frequency radio waves. It is not possible to efficiently heat, sterilize, or kill insects in the base layer of an asphalt pavement or the surface layer of soil simply by applying the irradiator vertically.

Furthermore, in devices where high-frequency radio waves are simply incident perpendicularly onto the irradiated object, the high-frequency radio waves are highly reflected on the surface of the irradiated object, which is the interface between different materials, making it difficult to efficiently irradiate high-frequency radio waves into the irradiated object. There was also a drawback that an alignment device had to be installed in the irradiation section or at a stage before the irradiation section. For example, according to the actual measurement results of the present inventors, when using an open waveguide applicator (waveguide WRJ-3), when high-frequency radio waves are vertically incident, the surface of the irradiated object is 17% , wood 10% reflection occurs.

This invention was made to eliminate the drawbacks of the conventional devices as described above, and an object thereof is to provide a high-frequency irradiation device with high irradiation efficiency.

FIG. 1 is a characteristic diagram showing the relationship between the angle of incidence of radio waves in the high frequency range on the irradiated object, the standing wave ratio, and the reflected power, which was obtained through research by the inventors of the present invention. If the angle of incidence of radio waves on the irradiated object is perpendicular (90 degrees), the reflection will be extremely large, but if the angle of incidence is less than 70 degrees for concrete and 60 degrees or less for wood, the reflection will be reduced. I understand. Note that in the figure, curve A indicates concrete blocks, and curve B indicates wood.

[Means for solving problems]

Accordingly, the present invention is an open-type high-frequency irradiation device configured so that the irradiation angle of radio waves in the high-frequency region to the object to be irradiated can be oriented at an angle of 70° or less.

[Effect]

In this invention, since the irradiation angle of the radio waves in the high frequency range can be oriented at an angle of 70 degrees or less, there is little reflection of the radio waves in the high frequency range on the surface of the irradiated object, and the high frequency power is efficiently applied to the irradiated object. Powered by

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. Fig. 2A shows the configuration of a high-frequency irradiation device that irradiates radio waves in a high-frequency range while oriented obliquely to the irradiated object, and Fig. 2B and C show a rotational introduction mechanism that arbitrarily varies the irradiation angle of high-frequency waves. This figure shows the configuration of a high-frequency irradiation device equipped with.

In Figure 2A, the irradiation angle of the irradiation part is as shown in Figure 1, for example, in the case of concrete blocks, it is 70 degrees or less, particularly preferably at an arbitrary angle between 20 degrees and 50 degrees, and in the case of wood If high-frequency radio waves are irradiated at an arbitrary angle of 60 degrees or less, preferably between 30 degrees and 50 degrees, the power efficiency increases by about 17% for concrete blocks and by about 9% for wood.

In Figure 2B, by applying a coaxial cable to the power transmission line, the irradiation angle of the oblique applicator can be made arbitrarily variable, so even if the physical properties of the object to be irradiated change, the surface Even when the shape changes, high-frequency power can be efficiently supplied to the irradiated object by making the irradiation angle follow the change.

In Fig. 2C, an example of a configuration in which a cylindrical waveguide with a rotationally symmetrical structure is applied to the power transmission path, the irradiation angle can be changed by a rotation introduction mechanism, and multiple irradiation ports are provided. It is.

As is clear from Figure 1, by orienting the irradiation part in the diagonal direction, efficiency is achieved over a wide range of irradiation angles, such as 20° to 50° for concrete and 30° to 50° for wood. Since it becomes possible to supply high-frequency radio waves to the irradiated object with good power, the physical properties of the irradiated object are non-uniform. High-frequency radio waves are always transmitted to all parts of the irradiation aperture, even when there are changes in physical properties such as variations, or when the surface shape of the irradiated object is uneven or sloped. There is no reflection, and high frequency power can be efficiently supplied to the irradiated object.

FIG. 3 shows an embodiment in which a plurality of irradiation ports are provided. FIG. 3A shows an example in which a single irradiation section 1 is provided with a plurality of irradiation ports 2, and FIG. 3B shows an irradiation unit in which a single irradiation section 1 is provided with a single irradiation port 2. This is an example of a high frequency irradiation device including a plurality of cylindrical waveguide lines 5 via a rotation introduction mechanism 4. In addition,
In the figure, 3 indicates the object to be irradiated, and arrow S indicates the direction of the high-frequency oscillation section. By providing multiple irradiation ports 2,
It is now possible to irradiate a wide area at the same time, and due to the nature of superposition of electromagnetic waves, Figure 3A,
By performing irradiation as shown in B, the high frequency electric field inside the irradiated object 3 can be increased, and the effect of deep heating, sterilization, insecticidal, etc. can be increased. Also,
The high-frequency irradiation device shown in FIG. 3A has the advantage that by combining it with a high-frequency phase shifter, the phases of the plurality of irradiation ports 2 can be adjusted and a desired directivity can be given to the high-frequency radio waves.

In addition, in the above example, the case where the object to be irradiated was a concrete block or wood was explained.
Needless to say, it is not limited to these.

〔Effect of the invention〕

As described above, according to the present invention, the irradiation angle of the open high-frequency irradiation device can be oriented at an angle of 70° or less with respect to the object to be irradiated, so that the deep part of the object to be irradiated can be efficiently heated and It can provide sterilizing, insecticidal, etc. effects.

[Brief explanation of the drawing]

Fig. 1 is a characteristic diagram showing the relationship between the irradiation angle and standing wave ratio of high-frequency radio waves measured using an aperture waveguide (WRJ-3), and Fig. 2 A, B, and C are each of the characteristics of the present invention. A configuration diagram showing a high-frequency irradiation device according to an embodiment, and FIGS. 3A and 3B are schematic diagrams each showing an embodiment in which a plurality of irradiation ports are provided. In the figure, 2 indicates an irradiation port, and 3 indicates an irradiated object.

Claims (1)

[Scope of Claims] 1. In an open high-frequency irradiation device capable of heating, sterilizing, killing insects, etc. by irradiating radio waves in a high-frequency range emitted from an irradiation port onto an irradiated object, A high-frequency irradiation device characterized by being configured so that the irradiation angle can be oriented at an angle of 70° or less. 2. The high frequency irradiation device according to claim 1, characterized in that a plurality of irradiation ports are provided. 3. The high-frequency irradiation device according to claim 1 or 2, wherein the irradiation angle can be arbitrarily varied. 4. The high-frequency irradiation device according to any one of claims 1 to 3, wherein the end surface of the irradiation port can be arranged parallel to the surface of the object to be irradiated.