JP2007092500A - Road reflecting mirror - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reflecting mirror having a function of preventing dew condensation, freeze and snow accretion from a mirror plane of the road reflecting mirror which is easily generated in cold season or early morning and is structured with substances having no harm for environmental conservation. <P>SOLUTION: A heat insulating material 18 is charged into a mirror plane 1A and a gelatinized heat accumulating agent is charged and adhered in a container 4 at the back of the heat insulating material. The reflecting mirror is incorporated by adhering heat insulating materials 6A, 6B at the back side of the container 4 and a back plate 2. And when disposing a reflecting mirror, there is no problem for environmental conservation by utilizing an alga such as an agar as a powder for gelation. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

    The present invention relates to a road reflector used by being installed on an outdoor road.

  Road reflectors are installed in places with poor visibility, such as road corners and intersections, to improve visibility through mirror surfaces and are used to prevent traffic accidents. However, when the temperature drops in the early morning, the mirror surface becomes cloudy and does not serve as a mirror surface.

  The reason why the mirror surface becomes cloudy in the early morning is that the surface temperature of the mirror surface falls below the ambient temperature and falls below the dew point. To prevent this, the mirror surface temperature should be higher than the ambient temperature.

  As a conventional anti-fogging measure, there is generally known a method for preventing fogging by energizing an electric heater built in the back side of the mirror surface when the temperature drops. In this method, the electric consumption is increased because the electric heater is energized at low temperatures regardless of cloudiness.

Japanese Utility Model Laid-Open No. 61-98901 Japanese Patent Laid-Open No. 4-97004 Japanese Patent Laid-Open No. 2-16207 Japanese Patent Laid-Open No. 2-204508

  As conventional known examples, Japanese Utility Model Laid-Open No. 61-98901 and Japanese Patent Application Laid-Open No. 4-97004 propose to form a latent heat storage layer between the mirror surface of the reflector and the back plate. Since it occurs in a wide temperature range from + 25 ° C. to −25 ° C., the anti-fogging function in the entire temperature range is not useful unless latent heat is generated only at a specific temperature.

  As another known example, in JP-A-2-16207 and JP-A-2-204508, an antifreeze liquid is put in a container between a mirror surface of a reflecting mirror and a back plate, and a heat insulating material is provided on the back side. A reflecting mirror with anti-fogging function that is integrated with the back plate and mirror surface has been proposed. Since the antifreeze liquid is put in the film container, there is a problem that the upper part of the mirror surface is clouded due to the drooping of the liquid and liquid leakage occurs due to a decrease in the sealing property of the film container.

  Other anti-fogging road reflectors that have been coated with titanium oxide on the mirror surface have been announced, but raindrops are less likely to adhere, and the mirror surface on rainy days is easier to see, but small condensation is attached. In addition, it was found that titanium oxide was not durable for more than a year and was not popularized.

As another known example, in JP-A-6-70832 and JP-A-7-3731, a heat buffer material is placed between the mirror surface of the reflector and the back plate, and then an aqueous solution of ethylene glycol is used as a heat storage agent. Gels by absorbing water into a water-absorbent resin, adds a cross-linking material with a synthetic polymer, gels it, puts it in a container, puts a heat insulating material on the back, mixes far-infrared radiation material, and installs a reflector It has been proposed to do. In the method of gelling by absorbing into a superabsorbent resin, the superabsorbent powder absorbs and swells more than 100 times and gels. Therefore, when it is put in a container, it hangs down to the lower part, and the upper part of the container becomes a cavity and causes fogging.
In the method of dissolving a synthetic polymer gel material in an aqueous solution and then adding a cross-linking material to gel, the gelation time varies greatly depending on the amount of the synthetic polymer material dissolved and the amount of cross-linking material added. Also, the gelation time varies greatly depending on the ambient temperature at that time, so that it is difficult to handle. Moreover, once gelled, there is a problem that it is impossible to dispose of the reflector by draining it into the drainage channel because of the irreversible gel that is insolubilized.

The present invention aims to solve these problems, and water, propylene glycol, ethylene glycol, so as not to freeze to −40 ° C. in a container in which a plastic film is bonded to the back surface of the mirror. Gelling powder made of red algae as a raw material is dissolved in an aqueous solution of sodium chloride, calcium chloride or the like in a weight ratio of 0.15 to 5.0%. This gel is composed of a substance that does not cause environmental problems as an edible or antifreeze agent.
A predetermined amount of the dissolved solution is filled in a container that matches the size of the mirror surface. The container containing the aqueous solution is heated to 85 ° C to 95 ° C. In order to raise the whole temperature uniformly, it puts in a warm water tank for a fixed time (5-10 minutes), and heats it. Thereafter, the heat storage agent-containing container is taken out of the hot water tank, placed on a horizontal table, and left to stand at a room temperature of 35 ° C. or lower for 2 to 4 hours for gelation. Place a container with a heat storage agent on the back side of the mirror surface of the reflecting mirror, and place a plastic or rubber foam on the back side to prevent water absorption. Use the back side as the back plate and the mirror surface and back plate with screws. Tighten or weld by spot welding.

  The anti-fogging function in this method is that the gelled heat storage agent is arranged up to the uppermost part of the mirror surface, so that the anti-fogging function acts over the entire reflecting mirror. In the manufacturing process of the heat storage agent, leveling can be performed without being affected by the ratio of the gelled material and the ambient temperature. Since the heat storage agent gel is reversible, it dissolves when heated to 60 ° C. or higher, so it dissolves and becomes an aqueous solution when added 2 to 3 times, so that water can be discharged into the drainage channel and environmental conservation can be improved. Regarding the cost of gelation, the heat storage agent can be reduced in cost by 2.5 to 1/3 compared with the method using the polymer gelling material.

By putting a heat insulating material directly behind the mirror surface, it is possible to release heat slowly over the morning without releasing the heat energy stored in the daytime heat storage agent in a short time.
Further, even when the outside air temperature rises in the early morning, it can be suppressed that the thermal energy of the heat storage agent remains and the temperature of the mirror surface temporarily falls below the outside air temperature to cause clouding.

According to the present invention, the effects of condensation, freezing, and snow accretion on the road reflector can be greatly improved compared to the conventional product (D). In addition, the heat storage agent can be reduced to 2.5 to 1/3 of the conventional product (D), helping to spread and contributing to prevention of traffic accidents in the early morning.
From the viewpoint of environmental conservation, when disposing of the reflector, the heat storage agent can be returned to an aqueous solution and diluted with water to be discharged into the drainage channel.

  An embodiment of a road reflector according to the present invention will be described in detail with reference to the drawings.

  The present invention will be described in more detail with reference to examples. FIG. 1 is a cross-sectional view of a road reflector according to the present invention. FIG. 2 is a perspective view in which a part of a container for storing a heat storage agent is cut out.

There are three types of road reflectors, round, 600φ, 800φ, and 1000φ, and two types, 450 × 600 and 600 × 800, are standardized as square shapes.
There are four types of mirror surface materials: stainless steel, acrylic, polycarbonate, and tempered glass. The heat storage type anti-fogging road reflector uses a stainless steel mirror to collect the outside air temperature. In the embodiment, an example of 800φ that is often used as a standard is shown.

In the case of 800φ, a heat insulating material 18 (polyethylene foam) of 5.0 t is put on the inner surface 1B of the mirror surface 1A. On the back, 6 g of powder agar is dissolved in 3.0 l of an aqueous solution in which propylene glycol and water are mixed at a ratio of 1: 4 and filled into a film container 4 having a diameter of 800φ. The aqueous solution placed in this container is placed in 90-95 ° C. hot water for 5 minutes, warmed, then water-equalized, and allowed to gel for 3 hours or longer at a temperature of 35 ° C. or lower.
The film container performs a uniform liquid amount seal 15 at a predetermined interval between two surfaces in order to make the heat storage agent uniform on the entire surface.

  On the back of the gelled container, heat insulating materials 6A and 6B (soft urethane foam) with a thermal conductivity of 0.03 (kcal / mh ° C.) having a thickness of 40 t at the center of the mirror surface are placed in a polyethylene bag. Then, the fastening portions 7 of the mirror plate 1 and the back plate 2 are spot welded. The outer periphery is wound by the outer peripheral band 19.

  Next, FIG. 3 shows a comparison result between the 800φ road reflector according to the present invention and the Wansei road reflector with anti-fogging device proposed in Japanese Patent Laid-Open No. 7-3731, hereinafter referred to as the conventional product (D).

  FIG. 3 is a graph in which the temperatures of the mirror surface and its surroundings are recorded and graphed for 24 hours. The reflector (A) according to the present invention has a higher temperature from night to 11:00 in the morning than the conventional product (D). Is shown. This is because when the amount of the heat storage agent is 800φ, the amount of 3.0 l is the optimum amount of heat collection and heat dissipation and the heat conduction amount of the heat insulating material just behind the mirror surface matches. is there. The heat energy is efficiently taken into the heat storage agent during the daytime when the temperature is high, and the heat energy stored in the heat storage agent is slowly released from the night to the morning. For that reason, the mirror surface temperature of the present invention is higher than that of the conventional product (D).

FIG. 1 is a partially cutaway cross-sectional view with a main portion showing an example of an embodiment of the present invention. FIG. 2 is a partially cutaway perspective view showing an example of a container for storing a heat storage agent. FIG. 3 is a graph showing the behavior of temperature change measured by comparing the performance of the road reflector (A) of the present invention and the conventional product (D).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mirror surface plate 1 Mirror surface plate 1A Mirror surface 1B Mirror surface inner surface 2 Back plate 3 Saddle plate 4 Container which puts gel-like heat storage agent 5 Gel-like heat storage agent 6A Heat insulating material 6B Heat insulating material 7 Mirror surface back plate fastening part 8 Support plate 9 Connection piece DESCRIPTION OF SYMBOLS 10 Pivot 11 Positioning stopper 12 Long groove 13 Column 14 Fastener 15 Equivalent liquid quantity seal 16 Outer seal 17 Inlet 18 Heat insulating material 19 Outer band

Claims (2)

  A water-soluble natural polymer gel is placed between the metallic mirror surface and the back plate in the mirror surface and back plate made of metal for traffic safety. The amount of the water is 0.3g / square cm to 1.2g / square cm per mirror surface area. The heat insulating material having a thermal conductivity of 0.02 to 0.05 (kcal / mh ° C.) is inserted on the back side with a thickness of 10 mm to 60 mm and integrated with the mirror surface and the back plate. Road reflector.   A heat insulating material with a thermal conductivity of 0.02 to 0.05 (kcal / mh ° C.) is placed in the thickness of 1.0 mm to 10.0 mmt immediately behind the mirror surface inside the mirror surface and back plate of the reflector. A road reflecting mirror characterized in that a water-soluble polymer gel is placed in a container on the back, and a heat insulating material is inserted on the back in a thickness of 10.0 mm to 60 mm and integrated with a mirror surface and a back plate. .

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