JPS585326Y2 - Reflector of square shield beam light bulb - Google Patents

Description

[Detailed description of the invention] The present invention relates to a reflector for a novel rectangular sealed beam light bulb, which has excellent strength, saves resources, and is light in weight, and also has an improved light distribution quality and does not generate sharp stray light. The purpose of this invention is to provide a reflector for a rectangular sealed beam light bulb that can completely eliminate this problem.

In the automobile industry of various countries, great efforts have been put into the development of rectangular sealed beam light bulbs due to their novel design.

In Japan as well, its development is being promoted in this industry.

The reflector a of the rectangular sealed beam light bulb currently being developed is basically a round sealed beam light bulb with its opening side (front ) The shape is determined by cutting off the top and bottom, left and right sides, and adding portions (flat surface portions) C2c, d, and d that are approximately parallel to the optical axis so that it has a horizontally long rectangle when viewed from ).

The reflecting mirror a of the rectangular sealed beam light bulb thus formed has an aluminum vapor deposited film f applied to its inner surface e to form a reflecting surface.

Formation of this aluminum vapor deposition film f is performed, for example, as follows.

That is, as shown in FIGS. 3 and 4, a filament coil i serving as an evaporation source is installed inside a box body with an opening g on one side, and an aluminum evaporation head is provided with an exhaust pipe j. The opening end 1 of the reflector a to which the aluminum vapor deposition film f is to be applied is brought into contact with the opening g of the reflector, and the exhaust pipe m formed on the reflector is closed using a closing tool n. The inside of the space 0 formed by the reflector a and the reflector a is sealed, and in order to improve the vapor deposition of aluminum onto the inner surface of the reflector a, an exhaust pipe j formed in the aluminum vapor deposition head k is passed through the space 0. to high vacuum.

Electricity is then applied to the filament coil i of the aluminum evaporation head to evaporate the aluminum foil p loaded in the filament coil i and adhere it to the inner surface of the reflecting mirror a to form an aluminum evaporation film f.

Most of the methods described above are used to apply the aluminum vapor deposition film f to the inner surface of the reflecting mirror a, but this method has the following various problems.

That is, in the step before applying the aluminum evaporation film f to the inner surface e of the reflecting mirror a, it is possible to improve the aluminum evaporation efficiency, to avoid discoloration of the aluminum evaporation film f due to combination of aluminum and impurity gas, Furthermore, in order to prevent the impure gas and the filament coil i from combining to form tungsten oxide and thereby burning the filament coil, the interior of the space 0 formed by the reflector a and the aluminum evaporation head is Although the vacuum is kept high, if the inside of the space 0 becomes high vacuum, the upper and lower flat surfaces c, c, which have a larger area than the left and right flat surfaces d, d, and the boundary between the flat surface C and the paraboloid of revolution q Tensile strain (stress) concentrates on part r, and fracture (implosion) may occur from the flat surface part C or boundary part r (occurs at a fairly high rate of about 1 in 1000 to 2000 pieces). .

). Once destruction occurs, the destructive force is so great that not only is it dangerous as fragments of the reflector a are scattered, but the vapor deposition equipment is also easily damaged, and the process will stop, even if only temporarily. It turns out.

Therefore, in the past, it has been considered to make the wall thicknesses of the flat surface parts c and d of the reflecting mirror a substantially equal to that of the paraboloid of revolution part q to strengthen the flat surface parts, especially the upper and lower flat surface parts C, against the above-mentioned tensile strain. However, if this is done, the mass of the reflector a increases, resulting in additional material costs and weight, which goes against the desire of automobile manufacturers to reduce the weight of automobiles.

In addition, if the wall thickness of the flat surface portion C is uniform, the magnitude of the stress remaining in that portion after the glass is thermally processed is proportional to the square of the glass wall thickness, so when forming the reflecting mirror itself, There is a problem that stress tends to remain in the flat surface portion C, and the strength of the reflecting mirror a decreases.

In addition, in the past, apart from this, the flat surface C of the reflecting mirror a is inclined so that it approaches the optical axis X-X as it goes to the rear of the reflecting mirror a, and the inclination angle θ is made relatively large. It was considered to disperse the tensile strain applied to the flat surface part C toward the paraboloid of revolution part q, thereby increasing the strength against the above tensile strain, but since the area of the opening of the reflecting mirror a is fixed, There is a drawback that the larger the inclination angle θ, the smaller the area of the paraboloid of revolution q, which is an effective reflecting mirror.

In addition, in this type of rectangular headlight, a shield plate is installed around the light source S except for the front part and the rear part in order to block so-called harmful rays that dazzle drivers of other vehicles and pedestrians. However, as the inclination angle θ of the flat surface portion C increases, the flat surface portion will come around to the rear of the light source S, so the shield plate t is provided accordingly.
must be brought close to the light source S.

However, if the shield plate t is brought too close to the light source S, impurity gas will be released from the shield plate t due to the temperature rise of the shield plate t, and this gas will combine with the light source S, which is a tungsten filament coil, and become tungsten oxide. There is a drawback that it has a negative effect on the life characteristics of the filament coil.

Furthermore, since the conventional reflecting mirror a is designed and manufactured so that the boundary part r between the flat surface part and the paraboloid of revolution part is angular, the light reflected by that part has sharp directivity, and moreover, varies depending on the product and cannot be controlled by the lens alone.Therefore, the shield plate t blocks the light source from the light source S to prevent the light beam from being irradiated to the boundary part r, but the inclination angle θ of the flat surface part C As becomes larger, the position of the boundary r moves backward and approaches the optical axis XX, so the shield plate t must be brought closer to the light source S.
Therefore, there is still a drawback that it adversely affects the life characteristics of the filament coil.

Therefore, the present invention aims to provide a reflector for a new rectangular sealed beam light bulb that is superior in strength, saves resources and is lightweight, and can eliminate the generation of sharp stray light in terms of light distribution quality. The paraboloid of revolution is cut out at the top, bottom, left and right so that it forms a substantially rectangular shape when viewed from the front direction, and a flat surface section extending substantially along the optical axis direction is provided at each edge. In a reflector made of hard glass having such a shape, the thickness of the flat surface portion is formed so as to gradually become thinner toward the open end of the reflector, and the paraboloid of revolution portion and the flat surface portion are further formed at their inner boundary portions. Hereinafter, specific embodiments shown in the accompanying drawings will be described in detail.

FIG. 5 shows the reflector 1 of the rectangular sealed beam light bulb of the present invention, and as shown in FIG. 1, the reflector 1 has a horizontally elongated substantially rectangular shape when the paraboloid of revolution is viewed from the direction of its opening. It is formed in such a shape that the top and bottom and left and right sides are cut out and flat surface portions 2, 2 and 3, 3 are connected to the top and bottom and left and right edges, respectively.

The flat surface portions 2, 2 and 3, 3 move toward the rear force, that is, the optical axis X/-
An angle θ' with respect to the optical axis X/-X/ is formed so as to approach / (this angle θ' is smaller than that of the conventional reflecting mirror a described above).

).

Further, the wall thickness t1 of the paraboloid of revolution portion 4 is formed to be approximately uniform over the entire surface, and the wall thickness t2 of each of the flat surface portions 2, 2 and 3, 3 is formed between the flat surface portion and the paraboloid of revolution. It is formed to be approximately equal to the wall thickness t1 of the paraboloid of revolution 4 near the boundary 5 with the surface and gradually become thinner toward the opening end 6, and furthermore, the inner surface of the boundary 5 has a radius of curvature 3, for example.
7IL is preferably a concave curved surface of about 2.8 to 3.5 mm.

That is, the paraboloid of revolution portion 4 and the flat surface portions 2, 2, 3, 3 are continuous by such a concave curved surface 5.

The reflecting mirror 1 thus formed is mounted on the aluminum vapor deposition head k shown in FIG.
An aluminum vapor-deposited film 8 is applied to the surface.

In addition, 9 is a light source arranged at approximately the focal point position of the reflecting mirror 1, and 10
covers the part of the light source 9 except for the front part and the rear part, that is, the light beam emitted from the light source 9 covers each flat surface part 2, 2 and 3,
It is a shield plate to prevent irradiation from 3.
A window 11 is formed on the front surface of the shield plate 10 below the optical axis X/-X/ for irradiating direct light from the light source 9 to the front of the reflecting mirror 1.

A part of the light beam emitted from the light source 9 passes through the window 11 of the shield plate 10 and is emitted in front of the reflecting mirror 1.
A portion of the other light beams travel toward the paraboloid of revolution portion 4, which is the effective reflecting surface of the reflecting mirror 1, and are reflected there and emitted to the front of the reflecting mirror 1.

Then, some of the other light rays are irradiated onto the boundary part 5 of the reflecting mirror 1, but since this boundary part 5 is a concave curved surface, it is not a sharp reflected light with directionality or directivity. Instead, it is reflected diffusely.

As mentioned above, the reflector of the rectangular sealed beam light bulb of the present invention is formed so that the wall thickness of each flat surface portion becomes gradually thinner toward the opening end of the reflector, and furthermore, the thickness of each flat surface portion is formed to be gradually thinner as it goes toward the opening end of the reflector, and the thickness of each flat surface portion is formed to be gradually thinner as it goes toward the opening end of the reflector. Since the boundary part is a concave curved surface, when the interior of the reflector is made into a high vacuum and an aluminum vapor deposited film is applied to the inner surface, the tensile stress generated on each flat surface part is dispersed in the direction of the paraboloid of revolution, and therefore the flat surface is There is an advantage that there is less destruction from the surfaces or boundaries, and the danger caused by it can be avoided, damage to the equipment can be reduced, and there is no need to stop the process, even if only temporarily.

In addition, in the present invention, the thickness of the flat surface portion is made to gradually become thinner toward the opening end of the reflecting mirror.
The material cost of the external reflector can be reduced, and the weight can be reduced to meet the needs of automobile manufacturers.

Furthermore, since the flat surface portion of the present invention is formed as described above, stress remaining in the flat surface portion during molding of the reflecting mirror itself is reduced, and there is an advantage that the strength of the flat surface portion does not decrease.

In addition, unlike conventional reflecting mirrors, the present invention prevents the tensile strain from being concentrated in one part without increasing the inclination angle of the flat surface, so the area of the paraboloid of revolution, which is the effective reflecting surface, is reduced. will not become less.

Furthermore, since the boundary part of the present invention is made into a concave curved surface, the generation of sharp stray light due to that part is eliminated, and there is no need to bring the shield plate close to the light source to forcefully eliminate irradiation to the boundary part. There is an advantage that the life characteristics of the light source, that is, the filament coil, will not be impaired due to the fact that they are too close to each other.

[Brief explanation of the drawing]

Figure 1 is a perspective view for explaining the method of forming the reflector of a square sealed beam light bulb, Figure 2 is a vertical side view showing an example of the reflector of a conventional square sealed beam light bulb, and Figure 3 is an aluminum vapor deposition head. FIG. 4 is a perspective view showing a state in which a reflector is attached to an aluminum vapor deposition head, and FIG. 5 is a vertical sectional side view showing a reflector of the rectangular sealed beam light bulb of the present invention. Explanation of symbols: 1: Reflector, 2, 2, 3, 3...Flat surface part, 4... Paraboloid of rotation part, 5... Inner boundary part, t.
・Thickness.

Claims (1)

[Scope of utility model registration request] Made of hard glass with a shape similar to that of a paraboloid of revolution, whose top and bottom, left and right sides are cut out so that it forms a substantially rectangular shape when viewed from the front direction, and a flat surface portion extending approximately along the optical axis direction is provided at each edge of the paraboloid of revolution. In the reflecting mirror, the thickness of the flat surface portion is formed to gradually become thinner toward the opening end of the reflecting mirror, and the paraboloid of revolution portion and the flat surface portion are further formed with a concave curved surface at an inner boundary thereof. A reflector for a rectangular sealed beam light bulb characterized by a series of continuous beams.