JP4669938B2 - Radio wave reflector for detecting road surface condition and method for forming the same - Google Patents

Description

  The present invention relates to a road surface state detection radio wave reflector and a method of forming the same.

Conventionally, what was disclosed by patent document 1 and patent document 2 as what provided the electromagnetic wave reflector layer in the surface layer of the road and formed another layer on it is known.
Both of them are intended to reduce radiated radio waves that interfere with communication when communicating with vehicles traveling at road toll booths in a short period of time. A radio wave absorbing material is provided to absorb radio waves.
JP 2001-311105 A JP 2002-81011 A

The above-described conventional radio wave reflector is provided to absorb radio waves. For this reason, the upper layer must be provided with a radio wave absorbing material to absorb radio waves to improve the absorption performance, and requires a thickness of at least 30 mm to 50 mm.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a road surface state detection radio wave reflector that improves radio wave reflectivity and reduces radio wave absorption performance as much as possible, and a method of forming the same.

In order to achieve the above object, the invention according to claim 1 is a radio wave reflector that forms a water film and reflects an irradiated radio wave transmitted through the water film, the radio wave reflector layer comprising a carbon fiber cloth, A dielectric layer which is an upper layer of the radio wave reflector layer and transmits the irradiation radio wave and a reflected radio wave reflected by the radio wave reflector layer, and made of a resin having a thickness of 30 mm or less And a plurality of hydrophilic particles attached to the surface of the dielectric layer .

  In the invention according to claim 1 configured as described above, since the thickness of the dielectric layer is 30 mm or less and the radio wave absorptivity is low, radio waves irradiated from above the road pass through the dielectric layer. Then, it is reflected almost 100% by the radio wave reflector layer made of the carbon fiber cloth below.

The dielectric layer made of resin exhibits a predetermined dielectric performance .

The thickness of the dielectric layer is 30mm or less, as a more preferred example, the upper Symbol dielectric layer average thickness may be 15mm or less.
Induced and the average thickness of the collector layer is 15mm or less, eliminates almost wave absorption, it can be reflected efficiently wave.

Further, on the surface of the dielectric layer, hydrophilic particles adhere.
Focusing on the performance of the dielectrics layer but tends to a high water repellency including a resin material material, by depositing a hydrophilic particles to the surface, the surface conformability water, repel rainwater Since it disappears, it is suitable for use as a road. In addition, such a radio wave reflector for detecting the road surface condition is premised on use in a concentration measuring device for an antifreezing agent previously filed by the present applicant, and in order for the device to operate, a water film is formed on the road surface. Need to be formed. Such a water film is formed by water adhering to the surface with hydrophilic particles, and the antifreezing agent concentration measuring device and the like can be operated with high accuracy.

As an example of the hydrophilic particles, the to the hydrophilic particles may be constituted by sand, to the hydrophilic particles may be constituted by gravel, and the hydrophilic particles composed of glass beads Also good .
There deviation have high hydrophilicity, also suitable as a material for road surfaces.
Further, the upper Symbol wave reflector layer may be fixed to a recess formed on the road surface by a resin adhesive.
The radio wave reflector layer in a recess formed on the road surface is secured by a resin adhesive, but because the radio wave reflector layer is a carbon fiber cloth resin adhesive tends soaks between the fibers, it was formed on the road surface It can be fixed with no gap between the inner peripheral surface of the recess. In addition, the same material as the dielectric layer can be used as the resin adhesive, and in this case, it functions as a part of the dielectric layer, and the dielectric constant may change in the dielectric layer. Absent.

As described above, the method of reflecting the irradiated radio wave by forming a relatively thin dielectric layer on the radio wave reflector layer made of carbon fiber cloth is not necessarily limited to the actual radio wave reflector that has been constructed. It can be easily understood that this also functions as a method. For this reason, the invention according to claim 4 is a method of forming a radio wave reflector that forms a water film and reflects an irradiated radio wave transmitted through the water film, wherein a radio wave reflector layer made of carbon fiber cloth is formed. A dielectric layer that is an upper layer of the radio wave reflector layer and transmits the irradiated radio wave and a reflected radio wave reflected by the radio wave reflector layer, and is made of a resin having a thickness of 30 mm or less The layer is formed by drying the paint, and before the paint is dried, a plurality of hydrophilic particles are dispersed on the surface of the paint, and the plurality of hydrophilic particles enter the surface of the paint by their own weight. It is configured to be attached .

And easy if, as this can be efficiently formed a road surface state detection wave reflector.
Na us, it is of course possible to apply the invention of the dependent claims in the road surface state detection wave reflector to the formation method.

The present invention described above, to provide a thin dielectric layer or a carbon fiber cloth capable you to nearly 100 percent reflected radio waves radiated from above the road by a road surface state detection wave reflector thick Can do.

Further, it is possible to exert a predetermined dielectric performance by a resin material forming the induction conductor layer. According to a resin material, that Do and suitable as a road surface without being peeled or cracked even thinner.

Et al is, without not repel rainwater familiar water on the front surface, is less likely caused slip. Further, it becomes easier to form and maintain a water film for operating the anti-freezing agent concentration measuring apparatus previously filed by the present applicant, and the apparatus can be operated with high accuracy.

Et al is, according to the invention according to claim 4, it is possible to construction of such useful road surface condition detecting wave reflector efficiently road surface.

  First, an embodiment of a concentration measuring device for an antifreezing agent using the radio wave reflector for road surface condition detection of the present invention will be described with reference to FIG. Reference numeral 1 denotes a radio wave transmission means, an oscillator 11 for generating an electric field having an oscillation frequency of several GHz or less (in this embodiment, 1.5 GHz to 3.5 GHz as will be described later), and an input signal is amplified. The transmission antenna 12 is configured to radiate as radio waves of several GHz or less.

  Reference numeral 2 denotes radio wave receiving means, which includes a receiving antenna 22 that receives radio waves reflected from the road surface R and a detector 21 that detects the received radio waves. The transmitting antenna 12 and the receiving antenna 22 are arranged side by side so that radio waves are irradiated onto the road surface substantially vertically by a supporting means such as a beam post.

  Reference numeral 3 denotes a transmission / reception change amount calculation unit that calculates the ratio of the reception intensity of the radio wave reception means 2 to the transmission intensity of the radio wave transmission means 1 as an attenuation amount (reflectance) of the radio wave. A frequency film thickness relationship storage unit that stores in advance a frequency film thickness relationship that associates the frequency at which the trend changes with the film thickness of the cryoprotectant, and 5 indicates the road surface condition from the change in the attenuation of the radio wave and the frequency film thickness relationship. It is a road surface state discriminating part which discriminates.

  6 includes a communication means, and outputs an antifreeze dissolved water determined by the road surface state determination unit 5 to a central observation device (not shown), and 7 stores a program for detecting the concentration of the antifreeze. The control program storage unit 8 controls the above 1 to 6 according to the set value of the sampling cycle and oscillation frequency set by the program of the control program storage unit 7 and a key switch (not shown) to measure the concentration of the antifreezing agent. CPU. Reference numeral 9 denotes a radio wave reflector made of carbon fiber cloth embedded in the road surface R such as asphalt, which is used when obtaining a more accurate detection result, and is embedded in the road surface.

Regarding the change in the ratio of the intensity of the irradiation radio wave and the reflected radio wave when a water film made of dissolved antifreeze is present on the road surface, Japanese Patent Application No. 2003-297672, which is a prior application of the present applicant. Details are described. The contents of this application are cited here.
FIG. 2 shows the radio wave reflector formed on the road surface R by its cross-sectional state.
The road surface R is made of asphalt or concrete, and a concave portion having a predetermined square and a predetermined depth is formed on the upper surface of the road surface R, and a carbon fiber cloth 91 and a dielectric 92 are laid. The carbon fiber cloth 91 is a woven fabric made of carbon fiber, and the weaving method and the like are not particularly problematic. However, since the reflected wave is used for measurement, it is preferable that the backside is less leaked. Since it is in a woven state, the thickness is 1 mm or less. The carbon fiber cloth 91 is disposed on the bottom surface of the recess, and an organic resin paint (for example, acrylic resin paint) is poured thereon to form a dielectric 92. The dielectric 92 is required to have a sufficiently low radio wave attenuation, a predetermined dielectric constant, and sufficient durability and weather resistance as a road surface even with a thickness of about 10 mm. . Looking for materials from such a viewpoint, the resin materials described above, particularly organic resin paints, are the most easily available and have good workability. Of course, other materials having similar properties can be substituted. In addition, although silica sand which is hydrophilic particles is dispersed and fixed on the surface of the dielectric 92, such hydrophilic particles may be mixed in the dielectric 92.

FIG. 3 is a flowchart showing the process of forming such a road surface state detection radio wave reflector.
Step S1 determines the measurement area. Here, the cutter is inserted into the outer frame portion of the measurement area to the depth to be cut. That is, a predetermined radio wave is transmitted by the transmitting antenna 12 and the reflected wave reflected by the carbon fiber cloth 91 is received by the receiving antenna 22 and used for measurement, but the intensity that can be received by the receiving antenna 22 In order to obtain a reflected wave, a substantially square area corresponding to the area to be calculated is determined, and the radio wave transmitted from the transmission antenna 12 is irradiated in consideration of the installation location of the transmission antenna 12 and the reception antenna 22. The position where the reflected wave is irradiated to the receiving antenna 22 is specified. Once this position is specified, insert the cutter along the four sides of the square. From the viewpoint of radio wave propagation characteristics, it is efficient to use a circular shape, but it is a square shape for ease of construction. Of course, it is possible to change the shape of the measurement region according to the road condition.

Next, in step S2, cutting in the measurement region is performed. Here, the inside of the measurement area in which the cutter is put in the outer frame is roughly cut by a large cutting machine. In general, cut vertically and horizontally in a grid, or cut diagonally and cut roughly.
In subsequent step S3, the cutting is finished. Since the measurement area is roughly cut in step S2, the cutting is performed to a specified depth by a small cutting machine or polishing machine. In this embodiment, it is about 11 mm (average thickness 11 mm). In the anti-freezing agent concentration measuring apparatus to which the present invention is applied, the concentration is measured using the ratio of the intensity of the irradiated radio wave and the reflected radio wave. At this time, the amount of attenuation based on the water film W formed on the road surface R is measured. Is used. For this reason, it is preferable that the radio wave attenuated by the radio wave reflector 9 is as small as possible, and it is necessary to be at least 30 mm, preferably within 15 mm, and more preferably within a few mm to a few dozen mm. In order to construct the dielectric 92 about 10 mm while the carbon fiber cloth 91 is about 1 mm, the depth of the recess is about 11 mm.

In step S4, the road surface cutting is completed. Completion of the road surface cutting is to confirm that the entire depth has become the specified depth, and the depth is confirmed at a plurality of points in the measurement region.
When the road surface cutting is completed, in step S5, a ground treatment with paint is performed. Here, an adhesive with asphalt or concrete and a paint are applied to the measurement region as a base treatment. The same acrylic resin paint as that of the dielectric 92 is used as the paint.
In step S6, carbon cloth is embedded. Here, before the previous paint dries, a carbon fiber cloth 91 of a specified size (which has been cut in advance according to the shape of the recess) is placed on the base paint.
In subsequent step S7, the carbon fiber cloth is processed. Since the carbon fiber cloth 91 is placed on the paint before drying in step ST6, the carbon fiber cloth 91 is pushed onto the paint so that the base paint soaks into the joints of the carbon fiber cloth 91. As a result, the paint oozes out through the joint, and can be adhered to the dielectric layer described later. As described above, the construction until the carbon fiber cloth 91 is embedded is completed.

In step S8, an overcoating process with paint is performed. The paint is poured onto the carbon fiber cloth 91 so that it is the same as the road surface.
In step S9, a final finishing process is performed. Here, finishing is performed so that the surface of the paint is flush with the road surface and the surface is uniform. In steps S8 and S9, hydrophilic particles such as silicon, gravel and glass beads may be mixed in the paint. Of course, it becomes acrylic mortar by mixing silicon and glass beads into acrylic paint.

  In subsequent step S10, a road surface hydrophilic treatment is performed. That is, the final finishing process is performed, and in a state where the surface of the paint is not yet dried, the silica sand is uniformly spread on the surface. Then, the silica sand enters the surface by its own weight and is simultaneously bonded to the surface. If it is also mixed inside the paint, even if the surface is scraped with a tire or the like, silica sand or the like is always present on the surface. By mixing sand such as silica sand, the organic resin coating becomes acrylic mortar, which is a suitable road surface material that is more difficult to break and peel.

In the final step S11, the paint surface is dried to complete the measurement road surface.
When rain water or the like is applied to the road surface R after drying, a substantially uniform water film W is formed by hydrophilic particles on the surface without repelling water on the upper surface of the dielectric layer 92 made of organic resin paint. Is done. FIG. 4 shows a state in which the surface is enlarged, and it can be seen that although the water film W is thinner than the particle size of the hydrophilic particles, a substantially uniform water film W is formed at the time of measurement by adapting to the particle surface.

  In this way, a thin recess of 30 mm or less is formed on the road surface, and after applying the adhesive and paint, the carbon fiber cloth 91 is placed thereon, and an organic resin paint is poured thereon to form the dielectric layer 92. By spreading and fixing hydrophilic particles on the surface, a radio wave reflector 9 for detecting the road surface condition suitable for measuring the water film W on the road surface by reflecting the irradiated radio wave is formed. It becomes possible.

1 is a block diagram of a concentration measuring device for an antifreezing agent that uses a radio wave reflector for detecting road surface conditions according to an embodiment of the present invention. 3 is a cross-sectional view of a radio wave reflector formed on a road surface R. FIG. It is a flowchart of the formation process of the radio wave reflector for a road surface state detection. It is an enlarged view of the water film of the upper surface of a dielectric material layer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Radio wave transmission means 11 ... Oscillator 12 ... Transmission antenna 2 ... Radio wave reception means 21 ... Detector 22 ... Reception antenna 3 ... Transmission / reception change amount calculation part 4 ... Frequency film thickness relation storage part 5 ... Road surface state determination part 6 ... Output part 7 ... Control program storage unit 8 ... CPU
9 ... Radio wave reflector 91 ... Carbon fiber cloth 92 ... Dielectric layer

Claims (4)

A radio wave reflector that forms a water film and reflects an irradiation radio wave transmitted through the water film ,
A radio wave reflector layer made of carbon fiber cloth,
A dielectric layer which is an upper layer of the radio wave reflector layer and transmits the irradiation radio wave and a reflected radio wave reflected by the radio wave reflector layer, and made of a resin having a thickness of 30 mm or less When,
A plurality of hydrophilic particles attached to the surface of the dielectric layer;
Road surface condition detecting wave reflector, characterized in that it comprises a. The road surface condition detecting radio wave reflector according to claim 1, wherein the plurality of hydrophilic particles adhere to each other with a gap on the surface of the dielectric layer . The dielectric layer is a dried paint.
The plurality of hydrophilic particles are dispersed on the surface of the paint before the paint dries, and enter and adhere to the surface of the paint due to their own weight.
The radio wave reflector for detecting a road surface state according to claim 1 . A method of forming a radio wave reflector that forms a water film and reflects an irradiated radio wave transmitted through the water film ,
Form a radio wave reflector layer consisting of carbon fiber cloth,
A dielectric layer which is an upper layer of the radio wave reflector layer and transmits the irradiation radio wave and a reflected radio wave reflected by the radio wave reflector layer, and made of a resin having a thickness of 30 mm or less Is formed by drying the paint,
A plurality of hydrophilic particles are dispersed on the surface of the paint before the paint dries, and a plurality of the hydrophilic particles enter and adhere to the surface of the paint by their own weight. Of forming a radio wave reflector for an automobile.

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