JPH0641683B2 - Road reflector - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement of a road reflector that is installed in a place with poor visibility at an intersection or a curve of a road, and in particular, a reflection that occurs during cold weather from night to early morning. The present invention relates to a road reflector having an anti-fog device for preventing the mirror from being fogged.

(Prior Art) A road reflector is a safety device that is installed in a place with poor visibility on the road, but the mirror surface is often clouded in cold weather and loses its function, which poses a danger in road traffic. Is strongly desired.

(Problems to be Solved by the Invention) The main cause of clouding of a road reflector is that the temperature of the mirror surface falls below the ambient temperature due to radiative cooling and falls below the dew point temperature, causing water droplets or ice particles (frost) on the mirror surface. It is to adhere.

To prevent the road reflector from becoming cloudy, it is sufficient to prevent the mirror surface from becoming colder than the surrounding air temperature.A method of heating by electric heat has been manufactured for a long time, but the maintenance cost is high and the power source is high. It has not been used so much since it was restricted by the installation site due to the need for the.

Recently, in order to reduce the temperature drop on the mirror surface due to radiative cooling, a cover provided above the mirror surface and an eave having a large eaves have been made.

In addition, in Japanese Patent Laid-Open No. 62-253808, in addition to the above-mentioned large eaves, a heat insulating material such as glass wool is attached to the back surface of this mirror surface plate, etc. Something that reduces the temperature drop has been proposed.

However, in the above, the anti-fog effect is reduced unless the reflecting mirror is directed downward from the vertical direction, so the installation position and the angle of the mirror surface are restricted, and as a result the viewing angle as a road reflecting mirror becomes small. There's a problem. Further, the effect of preventing fogging is not sufficient in actual use, and according to the experiment of the present inventor, in the experiment of 10 days in a cold region, dew condensation or frost (frost) adheres to the mirror surface of this road reflector for 3 days, It has been found that it does not fully function as a reflector.

In addition, in Japanese Utility Model Publication No. 61-198901, it is proposed to form a latent heat storage layer between the mirror plate and the back plate, but in the case of road reflectors, it is installed all over the country. Depending on the temperature, the surrounding temperature is also different. As described above, in order to exert a sufficient anti-fogging effect even at different temperatures depending on the installation location, it is effective to use a sensible heat storage material having a large heat storage amount at any temperature. Water has the largest amount of sensible heat storage in the same mass. In the case of a reflector, a device that uses a latent heat storage agent that reduces the amount of water to half or less in other temperature regions even if it has a heat storage amount of 3 to 4 times the sensible heat storage amount only at a specific temperature is a road reflector. Is not suitable as an antifogging device.

Forming a heat storage layer between the mirror plate and the back plate is effective in expecting an anti-fog function, but if a heat insulating material is not placed on the back plate side, heat will also be radiated from this back plate direction, The amount of heat radiated as a whole is increased and the antifogging effect is halved.

Further, Japanese Patent Application Laid-Open No. 63-167803 proposes a method in which a space between the mirror plate and the back plate is a closed container and an antifreeze liquid is injected into the container. The problem with this method is from the Japan Road Association
As for the stainless steel mirror plate with a road reflector pointer, round φ600 is 0.8 mm thick, φ800 mm is 0.9 mm thick, φ1000 mm is 1.0 mm
It is said to be thick. Regarding the distortion rate of the mirror surface, the meshes at intervals of 10 mm are made to face the mirror surface 1 m apart, and the degree of distortion of the map is visually checked against the limit sample. The method disclosed in JP-A-63-167803 also has a heat insulating material on the back plate side, like the one in the above-mentioned Japanese Utility Model Application Laid-Open No. 61-198901. The anti-fog effect is considerably reduced, and it is a method of adding antifreeze which is a sensible heat storage material, but if the mirror plate is φ 800 mm and the average distance between the mirror plate and the back plate is 3 cm, about 15 kg of antifreeze liquid As a result of the injection, a force that pushes the mirror surface plate in the bending direction and the lower direction acts, and the mirror surface plate is distorted in a downwardly swollen manner.

The present inventor solves the problems of conventional road reflectors with an anti-fog device, high price, narrow field of view, image distortion, insufficient heat retention, etc., and its anti-fog effect. The present invention, which is an efficient method, was carried out by conducting various experiments for the purpose of obtaining the knowledge that it is necessary to heat only the mirror surface of the road reflecting mirror with respect to the ambient temperature by using the heat storage material. It came to do.

(Means for Solving the Problems) The present invention is to provide a substantially uniform and heat-conductive contact between the mirror surface plate and the back plate of a road reflector on the inside of the mirror surface so that propylene glycol and water A container containing a sensible heat storage material that is a liquid phase at -20 ° C to + 40 ° C and is attached between the backside of the container and the back plate of the reflecting mirror. A road reflector characterized by being filled with material.

Further, as a means for achieving another object of the present invention, the sensible heat storage material-containing container is an aluminum foil which is entirely covered with a plastic film and hermetically sealed, and by configuring a road reflector with this, The heat storage material for keeping the road mirror warm, which is used for a long period of about 10 years, loses its anti-fogging effect gradually when the reduction (leakage) occurs during this long period. In addition to preventing loss (leakage), this container is made of a soft material such as aluminum foil so as to be substantially uniformly adhered to the entire inside of the mirror surface.

(Example) The present invention will be described with reference to the drawings, but this is an example for explaining the present invention, and the present invention is not limited to this example. .

FIG. 1 is a partially cutaway sectional view schematically showing the structure of a road reflector of the present invention.

FIG. 2 is a partially cutaway perspective view of a container containing a heat storage material.

In FIG. 1, 1 is a metal mirror plate having a mirror surface 1A having an appropriate curvature, 2 is a back plate integrally joined with a space for containing an appropriate content, and 3 is a projection above the mirror plate. It is an eave attached.

In the present invention, a container 4 which is in contact with the inside of the mirror surface of the mirror surface plate 1 and which is made of a mixed liquid of propylene glycol and water and contains a sensible heat storage material which forms a liquid phase at -20 ° C to + 40 ° C is stored. The container is filled with the sensible heat storage material 5, and the heat insulating material 6A is provided in close contact with the back surface of the container 4 in which the sensible heat storage material is placed.
A heat insulating material 6B is further provided between the heat insulating material 6A and the back plate 2 to prevent fogging due to dew condensation (frost) on the surface of the mirror surface plate 1. These heat insulating materials are preferably elastic so that they can also serve as a cushioning material.

Reference numeral 7 is a mirror surface back plate fastening portion that integrally connects the mirror surface 1 and the back plate 2, 8 is a support plate attached to the back surface of the back plate 2, and 9 is a connecting piece.
Reference numeral 10 is a pivot for pivotally supporting the connecting piece 9 on the mounting plate 8, 11 is a positioning clasp between the support plate 8 and the coupling piece 9, and 12 is a circle for fitting and fixing the positioning clasp 11. The arc-shaped long groove, 13 is a pillar for supporting the connecting piece 9, and 14 is a fastener for fixing to the pillar.

As a sensible heat storage material, it forms a liquid phase in a wide temperature range from about -20 ° C to + 40 ° C, has a large amount of heat storage per unit area, does not freeze even at low temperatures, and has no toxicity. A sensible heat storage material that exhibits stable performance over a long period of time is preferable. It is also necessary to fully consider the compatibility between this sensible heat storage material and the container in which it is placed.

In the examples of the present invention, considering the above conditions, for example, when a mirror surface having a diameter (φ) of 800 is used, the sensible heat storage material 5 composed of a mixed liquid of propylene glycol and water as an anti-fog additive is Put it in the container 4 and the mirror plate 1 and the back plate 2
Install between and.

In the case of a road reflector of φ800 (mm), it is suitable that the radius of curvature of the mirror surface is 3,000 (mm). It is desirable that the container 4 containing the sensible heat storage material 5 is closely attached to the inside 1B of the mirror surface with respect to this curved surface of the mirror surface. Further, it is desirable that the volume of the heat storage material per unit area of the central portion and the outer peripheral portion of the mirror plate 1 be substantially equal. When the temperature of the sensible heat storage material 5 is thin, the temperature of the sensible heat storage material 5 quickly rises when the temperature rises, but the sensible heat storage material 5 radiates heat quickly when the temperature drops, so that the antifogging effect is small. At a place where the sensible heat storage material 5 is thick, the mirror surface becomes cloudy during the temperature rise of the sensible heat storage material because the temperature rise of the sensible heat storage material is delayed. Further, as described above, the operating temperature is in a very wide range from -20 ° C to + 40 ° C, so that the container 4 for containing the sensible heat storage material 5 may be damaged even when the sensible heat storage material 5 expands in volume, or the sensible heat storage material 5 may be damaged. It is necessary that 5 does not dissipate to the outside. Considering these conditions, in this embodiment, the container 4 for containing the sensible heat storage material is used as a round container using a three-layer film in which both the front and back surfaces of the aluminum foil are bonded with a polyethylene film. , But is not limited to this.

Further, the film used for suppressing the long-term loss of the sensible heat storage material in the container 4 is configured so as to suppress the loss of the two surfaces together with the uniform liquid amount seal 15 and the outer peripheral seal 16 at regular intervals. To do. Container 4 for storing sensible heat storage material
An inlet 17 for inserting the sensible heat storage material 5 is attached to this.
Insulating materials 6A and 6B are placed between the container 4 containing the sensible heat storage material and the back plate 2. The heat insulating materials 6A and 6B are, for example, 40
Install two pieces, one with a thickness of mm x φ800 mm and the other with a thickness of 20 mm x φ400 mm.

During the daytime, more heat is collected from the mirror surface 1A and transferred to the sensible heat storage material 5 to store the heat during the time when the outside air temperature is high. In the present invention, when the outside air temperature decreases from night to early, heat is radiated only from the side of the mirror plate 1 to warm the mirror surface 1A from the inside and keep the temperature higher than the ambient temperature of the outside air.

Further, it is preferable that the sponge used as the sensible heat storage material is configured so that the container 4 containing the heat storage material is brought into close contact with the mirror surface inner side 1B by using elasticity so as to also serve as a buffer material.

FIG. 3 shows the results of a comparative test between the road reflector A of the present invention and a conventional road reflector B with an anti-fog device in which only the heat insulating material is used on the back surface of the mirror plate and the eaves above the mirror surface are increased. .

As shown in FIG. 3, the observation for 10 days in the cold district is a graph in which the temperature of the mirror surface and the temperature around it are recorded every morning at 6:30, and the temperature of the mirror surface of the road reflector of the present invention ( A) shows a temperature higher than the mirror surface temperature (B) of the conventional road reflector over the entire observation period and higher than the surrounding temperature (C). Conventional road reflector (B)
Indicates almost the same temperature as the ambient temperature (C).

Next, FIG. 4 shows a situation in which the road reflector of the present invention and a road reflector with a fog-preventing device disclosed in JP-A-63-167803 (hereinafter referred to as conventional product (D)) are compared and tested. Shown in.

FIG. 4 is a graph in which the temperatures of the mirror surface and its surrounding area are memorized and graphed for both of the above 24 hours. The mirror surface temperature of the road reflector of the present invention is higher than that of the conventional product (D) from night to early morning. It shows a high temperature. This is because the heat storage temperature energy released from the heat storage material after the ambient temperature starts to drop from the evening is radiated only from the mirror surface 1A side in the road reflector of the present invention, whereas the conventional product (D) Shows that the heat is radiated from both the mirror surface and the back plate side.

As is clear from the above comparative test results, the road reflector of the present invention exhibits a very effective anti-fog effect.

(Effects of the Invention) The present invention relates to an improvement of a road reflector provided at a road intersection or a place with poor visibility, in which cloudiness of the reflector that occurs from nighttime to early morning in cold weather or high humidity can be maintained for a long period of time. Therefore, there is a remarkable effect that the safety of road traffic can be enhanced by preventing the above-mentioned problems and always fulfilling the function of the road reflector.

Conventionally, various methods have been proposed for preventing fogging of road reflectors, but none of them have sufficient anti-fogging effect, causing problems during cold weather or high humidity.
In the present invention, this problem is solved by a simple configuration in which a soft thin metal container containing a sensible heat storage material is closely attached to the inside of the mirror surface of the reflecting mirror, and a heat insulating material is placed on the back surface of the container to insulate the back plate. did. That is, when a latent heat storage material is used as the heat storage material as in the conventional example, it is effective in a specific temperature range, but is less effective in other temperature ranges. In the present invention, the latent heat storage material is replaced with a sensible heat storage material composed of a mixed liquid of propylene glycol and water, so that the operating temperature is effectively in a very wide range from -20 ° C to + 40 ° C. It is an extremely excellent effect in industry that it can be used.

[Brief description of drawings]

FIG. 1 is a partially cutaway sectional view schematically showing the structure of a road reflector of the present invention, FIG. 2 is a partially cutaway perspective view of a container for containing a heat storage material, and FIGS. 3 and 4 are It is a characteristic view which shows the behavior of the temperature change measured by comparing the performances of the road reflector (A) of the present invention and the conventional products (B) and (D). 1 ... Mirror surface plate 1A ... Mirror surface 1B ... Mirror surface inside 2 ... Back plate 3 ... Eaves plate 4 ... Container for storing heat storage material 5 ... Heat storage material 6A, 6B ... Thermal insulation material 7 ... Mirror back plate tightening part 8 ... Support plate 9 … Coupling piece 10… Axis 11… Positioning clasp 12… Circular long groove 13… Column 14… Clamp 15… Equivalent liquid level seal 16… Outer peripheral seal 17… Injection port

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuo Nanjo 400-8 Fukui, Kurashiki-shi, Okayama Prefecture (72) Inventor Katsumi Tamura 590-1, Takao, Tsuyama-shi, Okayama (56) Bibliography 61-198901 (JP) , U) Showa 60-50210 (JP, U)

Claims (2)

[Claims] Claim: What is claimed is: 1. A road reflector is provided with a mirror plate and a back plate, which are substantially uniformly adhered to the inside of the mirror surface so as to be capable of heat conduction,
A container containing a sensible heat storage material, which consists of a liquid mixture of propylene glycol and water and forms a liquid phase at -20 ° C to + 40 ° C, is attached.
Moreover, a road reflector, wherein a heat insulating material is filled between the back side of the container containing the sensible heat storage material and the back plate of the reflector. 2. The road reflecting mirror according to claim 1, wherein the sensible heat storage material-containing container is an amyl foil which is entirely covered with a plastic film and hermetically sealed.