JP2007234449A - Vehicle lighting - Google Patents

Abstract

There is provided a vehicular lamp that can prevent discoloration deterioration of a reflecting surface and a reflector due to generation of a local heat accumulating unit without increasing the man-hour and cost required for assembly.
In a vehicular lamp having a reflector made of a synthetic resin and a reflecting surface integrally provided on the inner surface of the reflector, the synthetic resin for forming the reflector on the entire outer surface of the reflector or on some regions of the outer surface A member made of a different material is integrally formed. At this time, the integrally molded member is preferably made of a material having a higher thermal conductivity than the synthetic resin forming the reflector, such as metal, ceramics, and synthetic resin.
[Selection] Figure 1

Description

  The present invention relates to a novel vehicle lamp and a method for forming a reflector for a vehicle lamp. Specifically, the reflection surface and the reflector are deformed by heat generated by the light source bulb disposed in the lamp chamber of the reflector that constitutes the vehicular lamp, particularly on the reflector upper surface where the temperature is likely to rise due to convective heat transfer of air. In particular, the present invention relates to a vehicular lamp that can be prevented without using other components.

  An example of this type of conventional vehicular lamp will be described with reference to FIG. In FIG. 4, reference numeral 1 denotes a reflector that is integrated with a lamp chamber having an open front surface, and is made of, for example, a thermoplastic resin such as PPS, and has a reflective surface 2 integrally provided on the inner surface. The reflecting surface 2 is formed by providing, for example, an aluminum vapor deposition film with a thickness of 1000 angstroms, for example. The light from the light source bulb 3 mounted on the socket 4 is reflected by the reflective film 2 and is irradiated to the outside with a predetermined light distribution pattern. From the viewpoint of running safety, the amount of light of the vehicular lamp increases year by year, and the amount of heat generated from the light source bulb 3 increases accordingly. However, the thermoplastic resin forming the reflector 1 has a low thermal conductivity, Problems such as the occurrence of a predetermined light distribution pattern due to deformation of the reflecting surface 2 and the reflector 1 due to the occurrence of a local high-temperature heat storage section due to convective heat transfer of air in the lamp chamber and radiant heat from the light source bulb 3 There is.

  In order to solve these problems, Patent Document 1 discloses that a thermal conductive paint containing aluminum (Al) or carbon (C) is applied by robot spraying to a thickness of about 30 to 50 μm, or aluminum ( A layer having high thermal conductivity is provided on the outer surface of the reflector 1 by applying a sprayed film containing Al) or zinc (Zn) -aluminum (Al) alloy or the like to a thickness of about 100 to 300 μm by spraying. A method is disclosed.

Patent Document 2 discloses a method of providing a flat plate heat-resistant protector having a shape that does not contribute to the appearance and the distribution of light distribution in the lamp chamber.
JP 2000-195307 A JP-A-6-60703

  In Patent Document 2, it is possible to prevent discoloration deterioration of the reflecting surface 2 and the reflector 1 without contributing to the appearance and light distribution by installing a heat-resistant protector in the lamp chamber. There is a problem that the number of steps and cost required for assembly increase.

  In Patent Document 1, a reflective surface can be formed without using other components such as a heat shielding plate by providing a layer of high thermal conductivity by applying a thermal conductive paint or a thermal spray coating containing an alloy on the outer surface of the reflector 1. 2 and the reflector 1 can be prevented from being discolored. However, when the amount of heat generated from the light source bulb 3 is larger than the amount of heat diffused to the outside, there is a problem that a local high-temperature heat storage section is generated. is there.

  In order to solve the above-mentioned problems, the present invention provides a vehicular lamp having a reflector 1 made of a synthetic resin and a reflecting surface 2 integrally provided on the inner surface of the reflector 1, and the entire outer surface of the reflector 1 or the outer surface of the reflector 1. There is provided a vehicular lamp characterized in that a member 6 made of a material different from a synthetic resin forming the reflector 1 is integrally formed in some regions.

That is, the present invention
(1) In a vehicular lamp having a reflector made of a synthetic resin and a reflecting surface integrally provided on the inner surface of the reflector, the synthetic resin that forms the reflector on the entire outer surface of the reflector or in some areas of the outer surface A vehicular lamp characterized by integrally molding members made of different materials;
(2) The vehicular lamp according to (1), wherein the member is made of a material having a higher thermal conductivity than the synthetic resin forming the reflector.
(3) The vehicle lamp according to (1) or (2), wherein the member is at least one selected from metals, ceramics, and synthetic resins.
(4) The vehicular lamp according to any one of (1) to (3), wherein the member is integrally formed on the entire upper surface of the reflector or in some regions of the upper surface in a state of being attached to the vehicle body. (5) The vehicle lamp according to any one of (1) to (4), wherein the method of integrally molding the member on the outer surface of the reflector is insert molding.

  The vehicular lamp according to the present invention inserts a member 6 having a high thermal conductivity into the outer surface of the reflector 1 so that the convection heat transfer of air in the lamp chamber and the heat transmitted to the reflector 1 by the radiant heat from the light source bulb 3 are performed. Can be dissipated outside. As a result, it is possible to prevent the occurrence of local high-temperature heat storage portions of the reflecting surface 2 and the reflector 1. Therefore, discoloration deterioration of the reflecting surface 2 and the reflector 1 can be prevented without increasing the man-hours and cost for assembling parts such as a heat shielding plate and without requiring a process of applying a heat conductive paint or the like. it can. As the high thermal conductivity material, for example, high elastic modulus carbon fiber, metal such as copper, aluminum, iron, ceramics, carbon black, synthetic resin, or a composite thereof can be used.

  Furthermore, since a member having a high thermal conductivity is used, the heat dissipation effect can be increased as compared with a sprayed film containing a thermally conductive paint or alloy. Further, since the air heated by the light source bulb 3 rises by convection and collides with the upper surface of the reflector 1, heat is most easily stored in this portion. In the present invention, by inserting a member 6 having a high thermal conductivity on the upper surface of the reflector 1 where heat storage is most likely to occur, the reflective surface can be obtained without greatly affecting the formation of light distribution, the design and manufacturing costs of the reflector 1, and the like. 2 and the discoloration deterioration of the reflector 1 can be prevented.

  The best mode for carrying out the invention will be described below with reference to embodiments shown in the accompanying drawings.

  In FIG. 1, the reflector 1 has a hemispherical shape that can form a predetermined light distribution pattern by reflecting light emitted from the light source bulb 3. Examples of the thermoplastic resin used as the material of the reflector 1 include polyamide resin, polyolefin resin, polyester resin, polycarbonate resin, acrylic resin, polysulfone resin, polyphenylene ether resin, polyurethane resin, polyether resin, polyacetal resin, and the like. Alternatively, two or more types of thermoplastic resins may be used in combination. In addition, an antioxidant, a thermal stabilizer, a photodegradation inhibitor, a plasticizer, a lubricant, a release agent, a nucleating agent, which are added to a normal thermoplastic resin as necessary, as long as the object of the present invention is not impaired. Flame retardants, coloring pigments, dyes and the like can also be added. The thermoplastic resin is preferably a polyphenylene sulfide resin from the viewpoint of high thermal conductivity and excellent strength and rigidity at high temperatures, but is not limited thereto.

  The material of the member 6 that is integrally formed on the outer surface of the reflector 1 is a metal or alloy having a thermal conductivity of 5 to 500 W / mK, such as iron, copper, zinc, lead, or aluminum, or alumina, zirconia, mullite, silicon nitride, Ceramics having a thermal conductivity of 1 to 100 W / mK, such as silicon carbide, are preferable. Copper or copper alloy is particularly preferred because of its high thermal conductivity and low cost, but is not limited thereto. Alternatively, a synthetic resin material having a thermal conductivity of 0.5 to 50 W / mK compounded with a high thermal conductive material such as carbon fiber and inorganic particles can be used. From the viewpoint of affinity and adhesiveness with the reflector 1, the thermal conductivity is high. A polyphenylene sulfide resin of 0.5 to 30 W / mK is particularly preferred.

  The member 6 that is integrally formed on the outer surface of the reflector 1 is integrally formed on the entire outer surface of the reflector 1 or the entire upper surface in a state of being attached to the vehicle body, or several areas on the upper surface. From the viewpoint of cost and the like, it is more preferable to integrally mold only in the region immediately above the light source bulb 3 where the convection air heated by the light source bulb 3 hits the reflector 1. Further, the shape and dimensions of the member 6 are such that the thickness is 0.2 to 0.8 times that of the reflector 1 and the area 0.05 to 2.0 times the outer surface of the reflector 1 is in contact with the outside air. And shape is preferred.

  Insert molding is preferable as a method for integrally molding the member 6, but is not limited thereto.

  The region of the member 6 that is integrally molded on the outer surface of the reflector 1 is a part of the upper surface, the entire upper surface, and the entire outer surface, respectively, and the material of the integrally molded member 6 is alumina, iron, or copper. Table 1 and FIG. 5 show examples of numerical calculations performed by analysis software. The thickness of the integrally molded member 6 is ½ of the thickness of the reflector 1, the surface temperature of the light source bulb 3 is 600 ° C., and the air inside and outside the lamp chamber (assuming constant 25 ° C.) Assuming that only the upper half of the front surface of the reflector 1 is in and out, numerical calculations were performed in consideration of thermal radiation.

  According to these calculation results, the higher the region of the integrally molded member 6 and the higher the thermal conductivity, the lower the maximum temperature of the reflector 1, that is, the occurrence of the high temperature heat storage part.

Sectional drawing of the vehicle lamp which showed the case where the high thermal conductivity member was integrally molded in a part of reflector upper surface in the vehicle lamp of this invention. Sectional drawing of the vehicle lamp which showed the case where the high heat conductivity member was integrally molded in the whole reflector upper surface in the vehicle lamp of this invention. Sectional drawing of the vehicle lamp which showed the case where the high thermal conductivity member was integrally molded in the whole reflector outer surface in the vehicle lamp of this invention. Sectional drawing which showed the conventional vehicle lamp. The figure which shows the relationship with the reflector maximum temperature by the presence or absence of an integrally molded member, and the area | region of an integrally molded member.

Explanation of symbols

1: Reflector 2: Reflecting surface 3: Light source bulb 4: Socket 5: Lead wire 6: Integrally molded member

Claims (5)

In a vehicular lamp having a reflector made of a synthetic resin and a reflecting surface integrally provided on the inner surface of the reflector, the entire reflector outer surface or some area of the outer surface is made of a material different from the synthetic resin forming the reflector. A vehicular lamp characterized in that the member is integrally formed. The vehicular lamp according to claim 1, wherein the member is made of a material having a higher thermal conductivity than that of the synthetic resin forming the reflector. The vehicle lamp according to claim 1 or 2, wherein the member is at least one selected from metals, ceramics, and synthetic resins. The vehicular lamp according to any one of claims 1 to 3, wherein the member is integrally formed on the entire upper surface of the reflector or in some areas of the upper surface in a state of being attached to the vehicle body. The vehicular lamp according to any one of claims 1 to 4, wherein a method of integrally molding the member on the outer surface of the reflector is insert molding.

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