JPH0737403A - Reflector made of thermoplastic resin - Google Patents

Abstract

PURPOSE:To make a reflector applicable to a projector used for various transportations facilities and the like, by forming a thin wall part at least at a part of a connection between the top panel of the reflector having a high temperature rise in the lighting, and a paraboloidal surface close to the top panel. CONSTITUTION:A reflector 1 has a flat structure with a top panel 2 and the bottom surface 3 of a plain surface, and a paraboloidal surface 4 in the lateral direction, making the headlamp of an automobile as the object. By forming a thin wall part 5 at the paraboloidal surface side, at the part connecting the top panel 2 which is expanded by exposing a high temperature, and the paraboloidal surface 4, a phenomenon to deform the paraboloidal surface 4 following the expansion of the top panel 2 can be moderated. Such a part 5 can be plurally formed in parallel, and can be expected to function synergetically when the plural parts 5 moderate the deformation of the surface 4. As a result, the moulding process is made easy, as well as the light weight and a low cost can be realized. Consequently, it is applicable to a wide use of a transportation facilities and the like without using an aluminum alloy, a thermoplastic resin with a large specific gravity, and the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflector made of a thermoplastic resin for a lighting fixture, and more particularly to a heat used for a lighting fixture used in a nearly horizontal lighting posture in various transportation organizations such as automobiles, railway vehicles and ships. The present invention relates to a reflector made of a plastic resin.

In a variety of lighting equipment used for transportation such as automobiles, railroads, ships, etc., for example, a reflector of a headlamp, a metal plate is mainly processed into a sheet metal, a molded product of glass or a thermosetting resin, etc. The thing which vapor-deposited the reflective film on is widely used. Although these materials have stable properties,
It has drawbacks such as poor workability, high weight, and high price. For example, when a headlamp reflector made of these materials is adopted in an automobile or the like, it is against the demand for weight reduction and recycling.

In place of these materials, there is a tendency to adopt a thermoplastic resin in order to reduce the weight and reduce the cost.
However, with respect to the light distribution characteristics, it is unavoidable that they are disadvantageous as compared with those of sheet metal processing and BMC products, and it may not be possible depending on the design of the reflector.

Further, a thermoplastic resin having a low specific gravity cannot satisfy all the performance requirements of the reflector because of insufficient heat resistance and rigidity and an unsuitable linear expansion coefficient. In order to solve these drawbacks, an application filed by the same applicant, Japanese Patent Laid-Open No. 5-128903 (thermoplastic resin reflector) and Japanese Patent Laid-Open No. 5-128904 (thermoplastic resin reflector), has been proposed. .

The former discloses that an opening is provided on the top surface of the reflector, which becomes hot during lighting, but there is a drawback that light rays leak from this opening.

The latter discloses that a material having a small coefficient of linear expansion is inserted on the top surface which becomes hot.
Since different materials, for example, aluminum alloy plates are embedded, there is a problem that it becomes a problem at the time of recycling and is expensive.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermoplastic resin reflector in which the drawbacks of the conventional thermoplastic resin reflectors have been solved.

[0008]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a reflector made of a thermoplastic resin for a lighting equipment used in a transportation system, and a top surface of the reflector which becomes high in temperature during lighting.
The problem is solved by a reflector made of a thermoplastic resin, in which a thin portion is formed in at least a part of a joint portion with the parabolic surface which is close to the top surface. This material may be a thermoplastic resin having excellent heat resistance and mechanical properties, or a blend of plural resins. Furthermore, the subject of the present invention can be advantageously solved by integrally forming a rib for improving rigidity on the back of the parabolic surface of the reflector.

The thin portion to be considered here is formed, for example, in at least a part of the joint between the reflector top surface and the parabolic surface on the parabolic surface side within a range that does not significantly affect the formability and rigidity.

[0010]

In the present invention, the thin wall structure formed as described above alleviates the phenomenon that the reflector top surface expands due to the high heat caused by the intense beam, and the parabolic surface near the top surface tends to deform accordingly. To do. This thin portion is intended to prevent the phenomenon in which the optical axis changes by deforming the parabolic surface which is the reflecting surface under the influence of the deformation due to the expansion of the top plate.

Further, the rigidity of the parabolic surface can be enhanced by providing at least one rib integrally formed on the back of the parabolic surface. As a result, the deformation of the top surface due to high heat can be absorbed and alleviated only by the thin portion, the deformation of the parabolic surface can be prevented, and the deformation of the reflecting portion, and thus the change of the optical axis can be prevented.

[0011]

The present invention will be disclosed below with reference to the accompanying drawings showing the embodiments. FIG. 1 is a perspective view showing the structure of an embodiment of a reflector according to the present invention. The reflector 1 according to this embodiment is intended for a headlight of an automobile, and has a top surface 2
And the bottom surface 3 is a flat surface, and the left and right sides are parabolic surfaces 4 having a flat structure. A light source lamp such as a halogen lamp, an iodine lamp or the like, which generates high heat due to strong light emission, is attached to the light source attachment portion L. In the reflector having such a structure, the top surface 2 is closer to the light source (not shown) than the bowl type or the elliptic bowl type, so that the reflector is exposed to a high temperature and causes a large thermal expansion. .

In the embodiment of FIG. 1, a thin portion 5 is formed on the side of the parabolic surface where the top surface 2 and the parabolic surface 4 which are exposed to high temperature and expand are in contact with each other. With such a thin portion 5, it is possible to mitigate the phenomenon in which the top surface 2 expands and the parabolic surface 4 is deformed and deformed. A plurality of such thin portions 5 can be formed in parallel.
It can be expected that the plurality of thin portions 5 function synergistically in relieving the deformation of the parabolic portion 4.

FIG. 2 shows a second embodiment. In addition to the first embodiment shown in FIG. 1, ribs 6 are provided on the lower side of the thin portion 5 of the parabolic surface 4, that is, on the upper end of the parabolic surface 4. It is provided. By increasing the rigidity of the parabolic surface by such ribs 6, the deformation of the parabolic surface 4 is intended to be further reduced. Such rib 6
Is effective, but a larger effect can be expected by forming a plurality of them. Due to the configuration in which the thin portion 5 and the rib 6 are combined, the deformation that affects the parabolic surface 4 due to the deformation of the top plate 2 due to thermal expansion is blocked by the increased rigidity.

FIG. 3 shows a structure in which vertical ribs 7 are formed on the back surface of the parabolic surface in place of the horizontal ribs 6 shown in FIG. The ribs 7 increase the rigidity of the parabolic surface 4 and, at the same time, function as heat radiation blades. In this case, the ribs 7 can be provided so as to be evenly distributed over the entire back surface, or can be formed so as to be concentrated on the main part. Deformation can also be prevented by increasing the rigidity of the parabolic surface 4 with such a configuration.

In the first and second examples shown here, polyetherimide was used as the thermoplastic resin having high heat resistance. Polyetherimide is an engineering plastic with high heat resistance and high rigidity.
It is commercially available as EM (trademark; manufactured by Japan GE Plastics Co., Ltd.).

In order to confirm the effects of each of the embodiments shown in FIGS. 1 to 3, a reflector according to the prior art having a similar shape and having no thin portion or reinforcing ribs and a reflector according to each embodiment are used. After forming the respective reflective coatings, a light source was attached to the light source mounting portion L and a lighting test was conducted.

Irradiation was performed on the screen 7 m in front of these reflectors, and the angular displacement of the light cut surface was confirmed 3 minutes after lighting and 1 hour after lighting. In the reflector according to the prior art in which the thin portion and / or the rib structure is not provided, the value is 0.06 degrees, whereas it is 0.02 degrees in the first embodiment. In addition, it was confirmed that each of the second and third embodiments had an effect of 0.01 degree, which is obviously effective.

[0020]

According to the present invention, a reflector made of a thermoplastic resin can be realized as a reflector for a lighting fixture using a high power light source. Such a reflector is lightweight and inexpensive, can be easily molded, and can be recycled. Therefore, it is possible to obtain a reflector for a lighting fixture made of a thermoplastic resin suitable for a wide range of uses such as a transportation engine without using an aluminum alloy or other metal, a thermosetting resin, or a thermoplastic resin having a large specific gravity.

[Brief description of drawings]

FIG. 1 is a rear perspective view showing a first embodiment of a thermoplastic resin reflector according to the present invention.

FIG. 2 is a rear perspective view showing a second embodiment of the thermoplastic resin reflector according to the present invention.

FIG. 3 is a rear perspective view showing a third embodiment of the thermoplastic resin reflector according to the present invention.

[Explanation of symbols]

 1 Reflector 2 Top surface 3 Bottom surface 4 Parabolic surface 5 Thin portion 6 Horizontal rib 7 Vertical rib

Claims (3)

[Claims] 1. A reflector made of a thermoplastic resin for a lighting fixture used in a transportation system, wherein a top surface (2) of the reflector becomes high in temperature when turned on, and a parabola surface (4) close to the top surface. ), A reflector made of a thermoplastic resin, characterized in that a thin portion (5) is formed on at least a part of a joint portion with the reflector. 2. The thermoplastic resin reflector according to claim 1, wherein a plurality of the thin portions (5) are formed in parallel. 3. At least one rib (6, 6) for improving rigidity in a part of the back of the parabolic surface (4).
7) The thermoplastic resin reflector according to claim 1, wherein the reflector is formed.