JP2012107491A - Guard fence bolt, manufacturing method thereof, and guard fence - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a guard fence bolt with a head which allows retroreflecting light to have a wide range of incidence angle, with excellent light reflection performance.SOLUTION: A guard fence bolt comprises a chemical conversion treatment layer 2 formed on the surface of a bolt head, a primer layer 3 formed on the chemical conversion treatment layer 2, a retroreflection substrate layer 4 formed on the primer layer 3, and a retroreflective bead layer 5 formed on the retroreflection substrate layer 4.

Description

  The present invention relates to a protective fence bolt, a manufacturing method thereof, and a protective fence, and more particularly to a protective fence bolt capable of obtaining an excellent gaze guidance function at night, a manufacturing method of the bolt, and a protective fence using the bolt. It is.

  Conventionally, protective fences have been installed on roads and bridges for the purpose of preventing the vehicle from deviating outside the road and guiding the driver's line of sight, etc. However, the color and shape must be devised so as not to give a sense of incongruity as part of the landscape. These guidelines are included in the “Guidelines for the maintenance of protective fences in consideration of the landscape” (hereinafter referred to as “the landscape”). "Guidelines") were presented under the supervision of the Ministry of Land, Infrastructure, Transport and Tourism.

  In this “landscape guideline”, four colors of dark brown, gray beige, dark gray, and off-white are designated as basic colors, and it is basically selected as appropriate according to the landscape of the area used. Yes.

  Among these colors that take into account the landscape, dark brown is the color that is now mainstream in place of the conventional white when a protective fence is newly installed.

  However, dark brown, dark gray, and other dark colors are compatible with the surrounding landscape in the daytime, so the objectives of the “landscape guidelines” are achieved, but at night, they are comparable to the white guard fence. There was a problem that the gaze guidance effect of the driver could not be obtained.

  Therefore, as one means for enhancing the gaze guidance effect of the protective fence at night, a known retroreflective plate (gaze guidance mark) or retroreflective tape having a function of efficiently reflecting the headlight light of the vehicle to the driver side is used as the protective fence. It has been installed or applied.

  However, there is a problem that it takes time and labor to apply such a retroreflective plate or tape to the protective fence.

  As a means for solving the above problem, it is conceivable to use a bolt having a reflective coating formed on the head for construction of a protective fence. That is, if a bolt having a reflective coating formed on the head is used, the bolt is attached to the protective fence at predetermined intervals in order to fix the guard rail or the like to the support column, so that a visual line guiding effect is obtained. Moreover, since the bolt for constructing the protective fence also has a visual line guiding effect, the time and labor for separately installing the retroreflective plate or the retroreflective tape can be saved, leading to a reduction in the cost of installing the protective fence.

  It should be noted that the need for a separate retroreflecting plate or tape to be applied to the protective fence is not completely eliminated with only the bolt having a reflective coating on the head, but the installation quantity can be reduced to some extent. It is effective as a means, and accordingly, the time and labor required for forming the retroreflective plate or tape on the protective fence can be reduced.

  A bolt proposed to achieve the above object is disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 7-180121). Hereinafter, this bolt is referred to as a conventional bolt and will be described with reference to the drawings.

  FIG. 5 is a cross-sectional view showing a conventional bolt.

  As shown in FIG. 5, the conventional bolt includes a reflective layer 7 formed on the surface of the hemispherical bolt head 6 and a transparent protective layer 8 that covers the outer surface of the reflective layer 7.

  The reflective layer 7 is made of mirror glass powder obtained by vapor-depositing an aluminum thin film on one or both surfaces of a glass plate having a thickness of several tens of microns. The protective layer 8 protects the reflective layer 7 and is made of a transparent synthetic resin film.

  If the guard fence is constructed using the conventional bolt configured as described above, the headlight light of the vehicle irradiated to the bolt head 6 is reflected by the mirror glass powder, which contributes to the driver's line of sight guidance. .

JP-A-7-180121

  As described above, according to the conventional bolt, since the headlight light of the vehicle irradiated to the bolt head is reflected by the mirror glass powder, it contributes to the driver's line of sight guidance, but the ground mirror glass powder is used. Therefore, there is a problem that the incident angle range of the reflected light is narrow and the reflected light is irregularly reflected, so that the amount of light returning to the driver is small and the reflection efficiency is poor.

  Accordingly, an object of the present invention is to provide a guard fence bolt having a head having a wide light incident angle range and excellent light reflection performance, a method of manufacturing the bolt, and a guard fence using the bolt. There is.

  The present invention has been made to achieve the above object, and is characterized by the following.

  [1] A protective fence bolt comprising a retroreflective foundation layer formed on a surface of a bolt head and a retroreflective bead layer formed on the retroreflective foundation layer.

  [2] The protective fence bolt according to [1], wherein a constant reflection performance is obtained when the incident angle (θ) of light is within a range of 0 <θ ≦ 40 °.

[3] When the observation angle is 1.5 °, the reflection performance (cd / lx · m ² ) is in the range of 1.1 to 1.2, and the observation angle is 0.2 °. Has a reflection performance (cd / lx · m ² ) within a range of 12 to 14, according to [1] or [2].

  [4] The total thickness of the retroreflective foundation layer and the retroreflective bead layer is in the range of 90 to 120 μm, in any one of [1] to [3] The guard fence bolt described.

  [5] Any one of [1] to [4], wherein a primer layer is formed under the retroreflective base layer, and a chemical conversion treatment layer is formed under the primer layer. Bolt for protective fence as described in 1.

  [6] A protective fence using the bolt for a protective fence according to any one of [1] to [5].

  [7] In the method of manufacturing a bolt for a protective fence by forming a retroreflective foundation layer on the surface of the bolt head and then forming a retroreflective bead layer on the retroreflective foundation layer, the bolt head A synthetic resin in which a chemical conversion treatment layer made of zinc phosphate is formed on the part, and then a primer layer is formed by applying an epoxy resin on the chemical conversion treatment layer, and then mica is mixed on the primer layer. To form the retroreflective foundation layer, and when the retroreflective foundation layer is in a wet state, spray retroreflective beads on the retroreflective foundation layer to form the retroreflective bead layer. A method for producing a bolt for a protective fence, characterized by

  According to the present invention, it is possible to provide a guard fence bolt having a wide light incident angle range and a head having excellent light reflection performance. Therefore, if the guard fence is constructed with the bolt of the present invention, An excellent gaze guidance function at night can be obtained. In other words, the bolt of the present invention can cover a wide range of reflected light intensity with respect to the distance movement of the vehicle by the retroreflective function for the headlight light, so it has excellent gaze guidance effect for the driver and a sense of security. can get.

It is sectional drawing which shows the bolt for guard fences of this invention. It is a partial expanded sectional view which shows the bolt for protection fences of this invention. It is explanatory drawing (reprinted from "JIS-Z-9117") of a reflective performance test. It is a graph which shows the relationship between an incident angle and reflection performance, and the same figure (A) is a graph which shows the relationship between the incident angle and reflection performance when an observation angle is 1.5 degrees, and the same figure (B). These are graphs showing the relationship between the incident angle and the reflection performance when the observation angle is 0.2 °. It is sectional drawing which shows the conventional volt | bolt.

  One embodiment of the guard fence bolt of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view showing a protective fence bolt of the present invention, and FIG. 2 is a partially enlarged cross-sectional view showing a protective fence bolt of the present invention.

  1 and 2, 1 is a substantially hemispherical bolt head, 2 is made of zinc phosphate or the like formed on the surface of the bolt head 1 for the purpose of improving the adhesion of the coating film, or the like. The chemical conversion treatment layer 3 is formed on the chemical conversion treatment layer 2 for the purpose of improving the adhesion of a retroreflective foundation layer to be described later. The primer layer 4 is formed on the primer layer 3. The retroreflective foundation layer 5 is a retroreflective bead layer formed on the retroreflective foundation layer 4.

  The retroreflective foundation layer 4 is made of acrylic urethane resin or the like mixed with mica, and ensures the adhesion and color of the beads forming the retroreflective bead layer 5 to, for example, silver. The beads forming the retroreflective bead layer 5 are made of, for example, titanium barium-based glass, having a refractive index of 1.93, a specific gravity of 4.2, and a particle size of 90 to 106 μm. The thickness of the retroreflective bead layer 5 including the retroreflective foundation layer 4 is 90 to 120 μm.

  The effect of this retroreflection is caused by the retroreflection performance of beads and the reflection of the retroreflection base layer 4 with mica.

  Next, a reflection performance test for evaluating the retroreflection performance of the protective fence bolt of the present invention will be described with reference to FIG.

  In FIG. 3, the definitions of the irradiation axis, the observation axis, the observation angle, and the incident angle are as follows.

Irradiation axis: Axis connecting the projector to the center of the specimen surface.
Observation axis: Axis connecting the receiver to the center of the specimen surface.
Observation angle: The angle between the irradiation axis and the observation axis.
Incident angle: Angle between the irradiation axis and the normal of the specimen surface center.

  In this invention, the retroreflective performance is the performance of reflecting light in the direction of the projector. Therefore, the smaller the observation angle, the larger the retroreflection performance value.

  In the present invention, the retroreflective performance was evaluated with two observation angles of 0.2 ° and 1.5 °. This is because the observation angle between the light from the automobile headlight (irradiation axis in FIG. 3) and the driver's line of sight (observation axis in FIG. 3) is reflected by the driver's eyes (light receiver in FIG. 3) and reflection. Since it varies depending on the distance to the body (the surface of the test piece in FIG. 3), the smallest angle of 0.2 ° used in the “Guide to guide mark installation standard and explanation (published by the Japan Road Association)” Evaluation was made at both large angles of 1.5 °.

According to the guard fence bolt of the present invention described above, as shown in FIG. 4 (A), the incident angle (θ) of light is in the range of 0 <θ ≦ 40 ° and the observation angle is 1.5 °. In some cases, it was found that a constant retroreflection performance of 1.1 to 1.2 (cd / lx · m ² ) was obtained. Similarly, as shown in FIG. 4B, it was found that a constant retroreflection performance of 12 to 14 (cd / lx · m ² ) can be obtained when the observation angle is 0.2 °. In addition, when the observation angle is 1.5 °, the “measurement method 1” in “Retroreflection luminance coefficient measurement method” described later is used. When the observation angle is 0.2 °, the method of “measurement method 2” is used. Is the value obtained in.

  According to the bolt for a protective fence of the present invention, a bolt for a protective fence having a wide light incident angle range and a head having an excellent light reflection performance can be provided. It can be seen that an excellent gaze guidance function at night can be obtained by constructing protective fences for buildings or bridges.

  Although the above is a guard fence bolt having a hemispherical bolt head, it is needless to say that the shape of the bolt head is not limited to this.

  Next, the guard fence bolt of the present invention will be further described with reference to examples.

  First, a galvanized bolt having a hemispherical bolt head 1 as shown in FIG. 1 was prepared. This bolt is a normal bolt used when fixing a guardrail to a support | pillar.

  A chemical conversion treatment made of zinc phosphate was performed on the bolt head 1 to form a chemical conversion treatment layer 2. Next, an epoxy resin was applied on the chemical conversion treatment layer 2 to form a primer layer 3 having a thickness of 15 μm. Next, a silver acrylic urethane resin mixed with mica was applied onto the primer layer 3 to form a retroreflective foundation layer 4. Then, when the retroreflective base layer 4 was in a wet state, beads were sprayed onto the retroreflective base layer 4 by electrostatic spraying to form a retroreflective bead layer 5 on the retroreflective base layer 4. The beads used at this time are made of tambarium-based glass and have a refractive index of 1.93, a specific gravity of 4.2, and a particle size of 90 to 106 μm. The thickness of the retroreflective bead layer 5 including the retroreflective foundation layer 4 was 90 to 120 μm.

The retroreflection performance was evaluated by measuring the retroreflection luminance coefficient (cd / lx · m ² ) by the following ^two methods according to JIS-Z-9117.

Measurement method 1: A 250 W halogen light bulb is used as a light source, this light source is installed at a distance of 4 m from the object to be measured, and a Minolta luminance meter “CS-100” (trade name of the company) is measured as the light receiver. The retroreflective luminance coefficient (cd / lx · m ² ) was measured at a distance of 3.5 m from the distance of 1. The observation angle of the reflected light was set to 1.5 °. Was 800 Lux.

Measurement method 2: Using a retroreflective performance measuring instrument “NS-1 (trade name of the company)” manufactured by Suga Test Instruments Co., Ltd., measuring the retroreflective luminance coefficient (cd / lx · m ² ) at an observation angle of 0.2 °. did.

As a result of irradiating light to the bolt head portion of the protective fence bolt thus manufactured and examining the incident angle and reflection performance of the light, as shown in FIGS. When the angle (θ) is in the range of 0 <θ ≦ 40 ° and the observation angle by the measuring method 1 is 1.5 °, the reflection performance is 1.1 to 1.2 (cd / lx · m ² ). As a result, it was found that when the observation angle by the measuring method 1 is 0.2 °, the reflection performance of 12 to 14 (cd / lx · m ² ) can be obtained.

In addition to the above examples, the material and refractive index of the beads may be different (for example, 1.8 to 2.2) as long as they have retroreflective performance, and are not limited to the examples. Absent. Further, the photocatalyst coating (TiO ₂ ) having hydrophilicity and antifouling action may be applied to the outer surface of the beads.

1: Bolt head 2: Chemical conversion treatment layer 3: Primer layer 4: Retroreflective foundation layer 5: Retroreflective bead layer 6: Bolt head 7: Reflective layer 8: Protective layer

Claims (7)

  A bolt for a protective fence, comprising a retroreflective foundation layer formed on a surface of a bolt head and a retroreflective bead layer formed on the retroreflective foundation layer.   The bolt for a protective fence according to claim 1, wherein a constant reflection performance is obtained when the incident angle (θ) of light is within a range of 0 <θ ≦ 40 °. When the observation angle is 1.5 °, the reflection performance (cd / lx · m ² ) is within the range of 1.1 to 1.2, and when the observation angle is 0.2 °, 12 3. The protective fence bolt according to claim 1, wherein the bolt has a reflection performance (cd / lx · m ² ) within a range from 1 to 14. 4.   4. The protective fence bolt according to claim 1, wherein a total thickness of the retroreflective base layer and the retroreflective bead layer is in a range of 90 to 120 μm. 5. .   The protective fence according to any one of claims 1 to 4, wherein a primer layer is formed under the retroreflective underlayer, and a chemical conversion treatment layer is formed under the primer layer. bolt.   A protective fence using the protective fence bolt according to any one of claims 1 to 5.   In a method of manufacturing a bolt for a protective fence by forming a retroreflective bead layer on the retroreflective foundation layer after forming a retroreflective foundation layer on the surface of the bolt head, Form a chemical conversion treatment layer made of zinc acid, then apply an epoxy resin on the chemical conversion treatment layer to form a primer layer, and then apply a synthetic resin mixed with mica on the primer layer. Forming the retroreflective foundation layer, and spraying retroreflective beads on the retroreflective foundation layer when the retroreflective foundation layer is wet to form the retroreflective bead layer. A method for manufacturing a bolt for a protective fence.

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