JPH0159924B2 - - Google Patents

Description

[Detailed description of the invention]

(a) Technical Field of the Invention The present invention relates to a vehicle sunshade device that is used in the rear window of a vehicle, particularly an automobile, to block sunlight shining through the window while ensuring rearward visibility for passengers. (b) Prior Art and Problems As a conventional sunshade device for a vehicle, there is one described in, for example, Japanese Utility Model Application Publication No. 132123/1983. FIG. 1 is a sectional view thereof. That is, a light reflective grid body 3 having a honeycomb structure is attached to a rear window glass 1, and the grid body 3 is provided with transparent or anti-transparent resin plates on both sides thereof. 3a is a lattice. In a vehicle equipped with such a sunshade device, when an occupant in the vehicle interior B looks at the exterior C from the eyes 2 of the passenger, since the grid 3a is substantially horizontal, the grid 3a hardly enters the field of view and the rear part can be seen. Furthermore, since the sunlight A is reflected by the lattice body, it does not enter the vehicle interior B, thereby preventing the temperature inside the vehicle interior from increasing significantly, especially in the summer. However, in such a conventional sunshade device, since the space formed by the gratings 3a and 3a of the grating body 3 is air, there is a large difference in refractive index between the air and the resin plate 5. , the reflection from the resin plate 5 is large and a double image is formed. Particularly in recent years, passenger cars have had a problem in that the slope of the rear window glass is large, making double images more likely to occur and causing discomfort to passengers. (c) Purpose of the Invention The present invention aims to solve the problems of the conventional sunshade devices and provide a sunshade device that provides a clear rear view. (d) Structure of the Invention In order to achieve the above object, the sunshade device according to the present invention provides a fine light-transmitting device between two glass plates that is approximately horizontal when the glass plate is attached to a vehicle window glass. The gist is that membranes having channels are provided and are bonded together with an adhesive. (e) Examples This invention will be explained below based on the drawings. Second
The figure is a partially sectional explanatory view of the sunshade device of this embodiment. First, to explain the structure, the light shielding body 11, which is a sunshade device, includes, from the outside C side of the vehicle, an inorganic glass 6 with a thickness of 2.0 mm, a polyvinyl butyral adhesive film 7 with a thickness of 0.76 mm, a fine through-hole film 8 with a thickness of 0.25 mm, A 0.38 mm thick polyvinyl butyral adhesive film 9 and a 2.0 mm thick inorganic glass laminate 10 are laminated in this order. To explain the fine through-hole membrane 8 in more detail with reference to FIGS. 3 and 4, the through-hole width d = 0.5 mm, the network constituent membrane thickness l = 0.15, the through-hole membrane thickness h = 0.25, and the pore width ω.
The angle ξ of the fine through holes 12 forming a hexagonal light transmission path is 3.0 mm, and the angle is 37.9° with respect to the film surface. The shape of the through hole 12 is hexagonal. The following describes the procedure for manufacturing such light shielding property 11. A solid photosensitive film (trade name: Orcusta SST, manufactured by Tokyo Ohka Kogyo Co., Ltd.) was used to produce the fine through-hole membrane 8. A photomask film having a pattern having a hexagonal transparent portion shown in FIG. 3 was prepared by a conventional method. The photomask was brought into close contact with the surface of the photosensitive resin, and the sample surface was irradiated with irradiation energy of 16 mw/cm ² for 120 seconds using a mercury-xenon light source while keeping an inclination angle of 37.9° to the light irradiation surface, and then uncured with 2% caustic soda. The resin was washed away to produce a fine through-hole membrane 8 having a predetermined pattern. A 0.38 mm polyvinyl butyral film 9 is placed on the 2.0 mm thick glass 10 surface, and then a 0.25 mm thick fine through-hole film 8 made under the above conditions is placed on top of that, and then a 0.38 mm polyvinyl butyral film 9 is placed on top of the 2.0 mm thick glass 10 surface. The butyral film 7 and the glass 6 having a thickness of 2.0 mm are laminated and degassed in a vacuum as in the case of manufacturing laminated glass for automobiles. Thereafter, the desired light-shielding property 11 was created by heat-pressing in an autoclave at a temperature of 120° C. for 80 minutes and a pressure of 13.0 Kg/cm ² . In the light shielding body 11, the polyvinyl butyral films 7 and 9 melted during manufacturing, and a portion filled the through-hole portions 12 of the micro-through-hole film 8. The light shielding body 11 produced by the above method was arranged as a sunshade device to be mounted on a vehicle as shown in FIG. That is, the surfaces of the glasses 6 and 10 were fixed at an angle of 37.9 degrees with respect to the horizontal plane. In this state,
The transmittance of light from the light source was measured by sequentially changing the angle of incidence of light from the light source onto the light shielding body 11 with respect to the horizontal plane (line). The results are shown in the table below.

[Table] As can be seen from this experimental example, when the light shielding body 11 formed by enclosing such a micro-through-hole film 8 between the glasses 6 and 9 is used as a sunshade device, the sun's rays during the day and day can be clearly reduced. I know what to do. For the same reason, this prototype light shield also has the property of ensuring sufficient visibility from a predetermined viewpoint. That is, the light transmittance from the viewpoint horizontal to the fine through-hole 8 is 88%, which indicates that sufficient visibility is ensured and it can be sufficiently used as a rear window for a vehicle. The shape of the fine through-hole 8 of the sunshade device of the present invention, particularly the shape and dimensions of the through-hole 12, are determined by how the sunshade device is arranged. To specifically determine the shape of the through hole, use the following formula. FIG. 5 is a diagram showing a case where the light shielding body 11 of the present invention is attached to the rear window of a passenger car 13 to serve as a sunshade device. In this figure and FIG. 4, H: horizontal line, L: sunlight, 2: Viewpoint, T: Upper edge of the light shield 11, B: Lower edge of the light shield 11, ξ: Inclination angle of the light shield 11,: Elevation angle from viewpoint 2, φ:
Assuming that the angle between the horizontal line H and the light source, T: the transparency of the light shield 11 in the direction, γ ₁ : the angle between the sunlight and the horizontal plane H, and Tφ: the transmittance of parallel light from the light source, T={1-sgn/d /hsin/sin
ξsin (ξ+)}・100/1+l/d(%)……(1) Tφ={1-1/d/hsinφ/sinξs
in(ξ+φ)}・100/1+l/d(%)……(2) holds, and tanγ ₁ = d/h sinξ/1/sinξd/h cosξ…
...Since the relationship (3) holds true, these relationships are illustrated in Figure 6. For example, when it is perpendicular to the horizontal plane, that is, γ ₁ =90, d/h=2.06. In order to completely block the sun's rays from almost directly overhead, the condition of d/h = 2.06 needs to be met. If the relationship with T shown above is calculated based on this condition as a parameter of l/d, the result will be shown in FIG. That is, the elevation angle and depression angle of the glass end are generally within ±6 to 8 degrees, and within these ranges, it is basically desirable that T≧70%. Then, l/d=0.3 to 0.1 is a practical value. Next, the relationship between Tφ and φ is ξ=37.89°, d/h=
2.06, and the result calculated based on l/d=0.3 is shown in FIG. 8. Transmittance is 0% when φ=90°. In other words, if the sun is in the south and shining directly above the vehicle, the light can be virtually completely blocked from entering the vehicle interior. If the average transmittance at this time is Tφ, then φ=∫ ₀ n/2Tφdφ/n/2=35%. In this way, if the angle (inclination angle) ξ, transparency, transmittance φ, etc. of the light shield 11 with respect to the horizontal line H are determined,
l/d and d/h are determined by equations (1), (2), and (3),
By appropriately determining the value of any one of d, l, and h, other values can be determined, and a desirable fine through-hole membrane 8 can be created. In addition, in the above-mentioned embodiment, the fine through-hole membrane 8
Although the shape of the through hole 11 is shown to be a laterally long hexagonal shape, the shape may be round, round, square, or triangular, but a laterally long hole is preferable if possible. Regarding the glass plate, not only inorganic glass but also organic glass such as acrylic or polycarbonate may be used.The thickness should be 1.5 to 3.0 mm, taking into consideration strength and weight. It is preferable to use Of course, if one of the two glass plates is sufficiently thick, the other may be thinner than the above thickness. For adhesives, a film with fine light transmission paths is used.
When the light transmitting portion is formed of a through hole, the material and amount of the adhesive are preferably selected so that the through hole is sufficiently filled with the adhesive.
Regarding the material, it is preferable to use polyvinyl butyral. Although the through holes are preferably filled with adhesive when bonding the membrane and the glass plate, they may be filled with resin in advance. (F) Effects of the Invention As described above, the sunshade device of the present invention has a film disposed between two glass plates, which has a fine light transmission path that is approximately horizontal when the glass plate is attached to the vehicle window glass. Since it is installed and bonded together with adhesive, it reduces the amount of sunlight that enters while ensuring visibility, and since there is no air layer inside, there is no problem such as double vision. can get.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a conventional sunshade device, FIG. 2 is a cross-section of a light shield used in the sunshade device of the present invention, and FIG.
The figure is a partial plan view of the fine through-hole film of the light shielding body of the present invention, FIG. 4 is a cross-sectional view taken from FIG. 3, and FIG. Fig. 6 is a graph showing the relationship between the angle γ ₁ at which sunlight rays form a horizontal plane and the through hole size d/h; Fig. 7 is a graph showing the relationship between the angle formed by the horizontal plane of the line of sight and the transparency of the light shield; FIG. 8 is a graph showing the relationship between the sunlight angle φ and the transmittance. 6... Glass plate, 7... Adhesive, 8... Fine through-hole membrane, 9... Adhesive, 10... Glass plate, 11
... Light shielding body, 12 ... Light transmission path.

Claims (1)

[Claims] 1. A membrane having a fine light transmission path that is approximately horizontal when the glass plate is attached to a vehicle window glass is disposed between two glass plates, and is integrally bonded to the glass plate with an adhesive. A vehicle sunshade device featuring: