JP2005085653A - Vehicular lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively prevent a translucent cover from being thermally deformed by being locally heated by light from a light source reflected by the inside surface of a peripheral surface wall of a reflector, in a vehicular lamp having the reflector composed by forming the peripheral surface wall extending frontward on a front-end circumferential edge part of a reflector body. <P>SOLUTION: When the inside surface of the peripheral surface wall 14B of the reflector 14 is set as a nearly-cylindrical region 14b having a circular optical axis-orthogonal cross-sectional shape around an optical axis Ax over its entire circumference, the cross-sectional shape along a plane including the optical axis Ax of the nearly-cylindrical region 14b is set in a curved shape projecting toward the optical axis Ax. Therefore, light from the light source 12a entered into the region 14b is diffused in the longitudinal direction of the lamp to prevent light-entering positions to the translucent cover 16 from being concentrated on a region A in the vicinity of its optical axis. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vehicular lamp having a reflector in which a peripheral wall extending forward is formed on the outer peripheral edge of a front end of a reflector body.

  In general, a vehicular lamp includes a light source disposed on an optical axis extending in the front-rear direction of the lamp, a reflector having a reflecting surface that reflects light from the light source forward, and a transparent disposed in front of the reflector. It has a configuration with a light cover.

  In that case, as described in, for example, “Patent Document 1”, a vehicular lamp in which a peripheral wall extending forward is formed at the outer peripheral edge of the front end of the reflector body that forms the reflecting surface of the reflector is also known. .

Japanese Utility Model Publication No. 5-97008

  In such a vehicular lamp, when a region of a half or more circumference on the inner peripheral surface of the peripheral wall is set as a substantially cylindrical region having a substantially circular optical axis orthogonal cross-sectional shape centered on the optical axis, Since the light from the light source incident on the substantially cylindrical region is reflected toward the optical axis in the substantially cylindrical region, depending on the positional relationship with the light source, the light from the light source reflected by the substantially cylindrical region is The light is incident on the light-transmitting cover so as to be condensed in the region near the optical axis of the light-transmitting cover. For this reason, there exists a problem that a translucent cover will be heated locally at the time of lamp lighting, and it will become easy to produce a thermal deformation.

  On the other hand, if a plurality of grooves extending in the front-rear direction of the lamp as described in “Patent Document 1” are formed in the substantially cylindrical region, the light incident on the substantially cylindrical region from the light source. Can be diffusely reflected in the circumferential direction, so that the degree of condensing light to the region near the optical axis of the translucent cover can be relaxed to some extent.

  However, since the diffuse reflection in this case is performed in the circumferential direction, the diffusely reflected light is superimposed over the formation range of the substantially cylindrical region in the entire substantially cylindrical region. There is a problem that the degree of light collection cannot be relaxed sufficiently.

  The present invention has been made in view of such circumstances, and in a vehicular lamp having a reflector in which a peripheral wall extending forward is formed on the outer peripheral edge of the front end of the reflector body, the inner peripheral surface of the peripheral wall It is an object of the present invention to provide a vehicular lamp that can effectively suppress thermal deformation caused by locally heating a translucent cover by light from a reflected light source.

  In the present invention, the object is achieved by devising the shape of the inner peripheral surface itself of the peripheral wall.

That is, the vehicular lamp according to the present invention is
A light source disposed on an optical axis extending in the front-rear direction of the lamp, a reflector having a reflecting surface that reflects light from the light source forward, and a translucent cover disposed in front of the reflector. ,
The reflector has a peripheral wall extending forward from the outer peripheral edge of the front end of the reflector body forming the reflective surface, and a region of at least a half circumference on the inner peripheral surface of the peripheral wall is centered on the optical axis. In the vehicular lamp set as a substantially cylindrical region having a substantially circular optical axis orthogonal cross-sectional shape,
A cross-sectional shape of the substantially cylindrical region along a plane including the optical axis is set to a curved shape that is convex toward the optical axis.

  The above-mentioned “peripheral wall” does not necessarily have to be formed over the entire circumference as long as a region having a half or more circumference on the inner peripheral surface is set as a substantially cylindrical region.

  The “optical axis orthogonal cross-sectional shape” means a cross-sectional shape along a plane orthogonal to the optical axis.

  If the cross-sectional shape along the plane including the optical axis of the “substantially cylindrical region” (hereinafter also referred to as “axial cross-sectional shape”) is set to a curved shape that is convex toward the optical axis, The specific curve shape, curvature, etc. are not particularly limited.

  As shown in the above configuration, in the vehicular lamp according to the present invention, a reflector having a reflective surface that reflects light from a light source forward is forward from the outer peripheral edge of the front end of the reflector body that forms the reflective surface. It has a peripheral wall that extends, and an area of half or more of the inner peripheral surface of the peripheral wall is set as a substantially cylindrical area. In this substantially cylindrical area, the axial cross-sectional shape is directed toward the optical axis. Therefore, the following operational effects can be obtained.

  That is, since the substantially cylindrical region has a substantially circular optical axis orthogonal cross section centered on the optical axis, light from the light source incident on the substantially cylindrical region is transmitted to the optical axis in the substantially cylindrical region. However, the light from the light source reflected by the substantially cylindrical region is reflected by the lamp because the axial cross-sectional shape of the substantially cylindrical region is set to a curved shape that is convex toward the optical axis. Since the light is diffused in the front-rear direction, it is possible to prevent the light incident position on the translucent cover from concentrating on the region near the optical axis.

  At this time, since this diffuse reflection is performed in the front-rear direction of the lamp orthogonal to the circumferential direction, the diffusely reflected light is superimposed over the formation angle range of the substantially cylindrical region as a whole, and the optical axis of the translucent cover. The possibility of condensing light in the vicinity area can be eliminated.

  As described above, according to the present invention, in the vehicular lamp including the reflector having the reflector formed with the peripheral wall extending forward at the outer peripheral edge of the front end of the reflector body, the light source reflected from the inner peripheral surface of the peripheral wall is used. It is possible to effectively suppress the light transmission cover from being locally heated by light and causing thermal deformation. Thereby, it is possible to eliminate the necessity of providing a heat-resistant structure or heat-treating the translucent cover. Further, the mold structure of the reflector can be simplified as compared with the conventional case where a plurality of grooves extending in the front-rear direction of the lamp are formed on the inner peripheral surface of the peripheral wall.

  Such an effect can be obtained when a region of a half or more of the inner peripheral surface of the peripheral wall is set as a substantially cylindrical region. In this case, the inner peripheral surface of the peripheral wall extends over the entire periphery. When the substantially cylindrical region is set, the amount of reflected light from the substantially cylindrical region that is incident on the region near the optical axis of the translucent cover is maximized. It is effective.

  As described above, the axial cross-sectional shape of the “substantially cylindrical region” is not particularly limited, but the radius from the optical axis of each point in the substantially cylindrical region increases monotonously toward the front of the lamp. If the configuration is set to, it is possible to prevent undercutting when the reflector is molded, and therefore it is possible to eliminate the need to provide a slide mechanism or the like in the mold structure.

  In the above configuration, if the light diffusion structure is provided in the substantially cylindrical region, the light diffusion effect by the light diffusion structure can be obtained in addition to the light diffusion effect by the shape of the substantially cylindrical region itself. It can suppress more effectively that a translucent cover will be heated locally by the light from the light source reflected in the shape area.

  In this case, the specific configuration of the “light diffusing structure” is not particularly limited, and for example, it may be a configuration that has been subjected to texture processing, frost processing, or the like. If a plurality of groove portions extending in the direction are configured, the light from the light source reflected by the substantially cylindrical region can be efficiently diffused in the lamp front-rear direction and the circumferential direction without hindering the moldability of the reflector. This can further effectively suppress the translucent cover from being heated locally.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a front view showing a vehicular lamp according to an embodiment of the present invention, and FIGS. 2 and 3 are side sectional views thereof.

  As shown in these drawings, the vehicular lamp 10 according to the present embodiment is a backup lamp disposed at the rear end of the vehicle, and includes a light source bulb 12, a reflector 14, and a translucent cover 16. It has an optical axis Ax extending in the lamp front-rear direction.

  The light source bulb 12 is an incandescent bulb having a filament as the light source 12a. The light source bulb 12 is fitted and fixed in the bulb insertion hole 14c of the reflector 14 so that the light source 12a is positioned on the optical axis Ax.

  The reflector 14 includes a substantially bowl-shaped reflector body 14A, and a peripheral wall 14B that extends forward from the outer peripheral edge of the front end of the reflector body 14A (frontward as the vehicle lamp 10 and rearward as a vehicle, the same applies hereinafter). It is made up of.

  The reflector body 14A has a reflecting surface 14a that reflects light from the light source 12a forward. The outer peripheral edge portion of the front end of the reflecting surface 14a is set to a circle whose center is the optical axis Ax, and its diameter is set to a value of about 60 to 65 mm. The reflecting surface 14a has a plurality of reflecting elements 14s formed concentrically on a rotating paraboloid focusing on the position of the light source 12a on the optical axis Ax. Each of the reflecting elements 14s diffuses and reflects the light from the light source 12a in the radial direction at a predetermined diffusion angle, as shown in FIG.

  The peripheral wall 14B extends in a substantially cylindrical shape toward the front of the lamp, and the inner peripheral surface thereof is set as a substantially cylindrical region 14b having a circular optical axis orthogonal cross section centered on the optical axis Ax over the entire circumference. ing. In the substantially cylindrical region 14b, a cross-sectional shape along a plane including the optical axis Ax is set to a curved shape that is convex toward the optical axis Ax. In the present embodiment, the shaft-containing cross-sectional shape is set to a single arc shape. As a result, the substantially cylindrical region 14b diffuses and reflects light from the light source 12a in the front-rear direction of the lamp at a predetermined diffusion angle, as shown by the solid light path in FIG.

  At that time, the radius from the optical axis Ax of each point in the substantially cylindrical region 14b is set to monotonously increase toward the front side of the lamp. The draft angle (that is, the angle formed with the optical axis Ax in the plane including the optical axis Ax) at the rear end position of the substantially cylindrical region 14b is set to a value of about 3 °.

  In this substantially cylindrical region 14b, a plurality of grooves 14g extending in the front-rear direction of the lamp are formed over the entire circumference as a light diffusion structure. Each groove 14g has a convex cylindrical surface, and is formed over a range from the rear end position of the substantially cylindrical region 14b to a slightly rear position of the front end position. As a result, each groove 14g diffuses and reflects light from the light source 12a in the circumferential direction at a predetermined diffusion angle, as shown in FIG.

  The translucent cover 16 is formed in a through shape, and is fixed to the outer peripheral edge of the front end of the peripheral wall 14B by ultrasonic welding or the like at the outer peripheral edge thereof.

  FIG. 4 is a graph showing the results of tests performed to confirm the effectiveness of adopting the configuration of the vehicular lamp 10 according to the present embodiment.

  This test was conducted to examine how the temperature of each part of the lamp changes when the vehicular lamp 10 is placed in an atmosphere of 50 ° C. and repeatedly turned on and off for 1 hour.

  At that time, the voltage applied to the vehicular lamp 10 was 13.5 V, and the lighting time and lighting time per time were 5 minutes each. The temperature measurement was performed at four points P1, P2, P3, and P4 shown in FIG. The measurement point P1 is a position on the optical axis Ax on the inner surface of the translucent cover 16, the measurement point P2 is a position directly above the light source 12a on the inner peripheral surface of the peripheral wall 14B, and the measurement point P3 is a reflector body 14A. The measurement point P4 is the upper end position of the valve insertion hole 14c of the reflector body 14A.

  As apparent from the graph shown in FIG. 4, the temperature of each part of the lamp gradually increased by repeatedly turning on and off, but the rate of increase gradually decreased. And within the measurement time of 1 hour, the temperature of each part of the lamp becomes highest at 55 minutes after the sixth lighting is finished, and is 91.6 ° C. at the measurement point P1 and 98.9 ° C. at the measurement point P2. The measurement point P3 was 84.8 ° C., and the measurement point P4 was 74.7 ° C.

  FIG. 5 is a graph showing the results of a similar test performed on a vehicular lamp according to a comparative example.

  The vehicular lamp according to this comparative example has the same basic configuration as the vehicular lamp 10 according to the present embodiment, but the configuration of the peripheral wall of the reflector is different. That is, in the vehicular lamp according to this comparative example, as shown by a two-dot chain line in FIG. 3, the inner peripheral surface 14b ′ of the peripheral wall is configured as a conical surface with the optical axis Ax as the center. At this time, the inner peripheral surface 14b 'is set so that the positions of the front and rear end edges thereof coincide with the positions of the front and rear end edges of the substantially cylindrical region 14b. In addition, the inner peripheral surface 14b ′ is not formed with a light diffusion structure such as the plurality of grooves 14g formed in the substantially cylindrical region 14b.

  For the vehicular lamp according to this comparative example, temperature measurement was performed at three points P1, P2, and P3 shown in FIG.

  As is clear from the graph shown in FIG. 5, in the vehicular lamp according to the comparative example, the temperature of each part of the lamp gradually increases due to repeated turning on and off, and the rate of increase gradually decreases. The temperature of each part of the lamp became the highest. At that time, the measurement points P2 and P3 were 101 ° C. and 91.4 ° C., respectively, and were not so different from the measurement result of the vehicular lamp 10 according to the present embodiment, but regarding the measurement point P1, 125.9. The measurement result of the vehicular lamp 10 according to the present embodiment was significantly higher than the measurement result of 91.6 ° C.

  As described above, the temperature measurement value at the measurement point P1 is significantly higher than the measurement result of the vehicular lamp 10 according to this embodiment. The inner peripheral surface 14b ′ of the peripheral wall also has a lamp front-rear direction. There is no light diffusing action in the circumferential direction, and as indicated by the broken light path in FIG. 3, light from the light source 12a incident on the inner peripheral surface 14b ′ is in the vicinity of the optical axis with respect to the translucent cover 16 (FIG. 3). This is considered to be caused by a large amount of incident light on the region indicated by A in FIG.

  As described in detail above, in the vehicular lamp 10 according to the present embodiment, the inner peripheral surface of the peripheral wall 14B of the reflector 14 is set as the substantially cylindrical region 14b over the entire circumference, and the substantially cylindrical region 14b is Since it has a circular optical axis orthogonal cross section centered on the optical axis Ax, the light from the light source 12a incident on the substantially cylindrical region 14b is reflected toward the optical axis Ax by the substantially cylindrical region 14b. However, since the shaft-containing cross-sectional shape of the substantially cylindrical region 14b is set to a curved shape that is convex toward the optical axis Ax, the light from the light source 12a reflected by the substantially cylindrical region 14b is the lamp. The light is diffused in the front-rear direction, so that it is possible to prevent the light incident position on the translucent cover 16 from concentrating on the optical axis vicinity region A in advance.

  At this time, since the diffuse reflection is performed in the front-rear direction of the lamp orthogonal to the circumferential direction, the diffuse reflection light is superimposed over the formation angle range of the substantially cylindrical region 14b even in the entire substantially cylindrical region 14b. It is possible to eliminate the possibility of focusing on the region A near the optical axis.

  As described above, according to the present embodiment, the light transmission cover 16 is locally heated by the light from the light source 12a reflected by the inner peripheral surface of the peripheral wall 14B, and the thermal deformation is effectively suppressed. be able to. Thus, it is possible to eliminate the need for providing a heat-resistant structure or heat-resistant treatment on the translucent cover 16.

  At that time, like the vehicular lamp 10 according to the present embodiment, when the inner peripheral surface of the peripheral wall 14B is set as a substantially cylindrical region 14b over the entire periphery, the vicinity of the optical axis of the translucent cover 16 Since the amount of reflected light from the substantially cylindrical region 14b incident on the region A increases, it is particularly effective to employ the configuration of this embodiment.

  Further, the vehicular lamp 10 according to the present embodiment is formed so that the radius from the optical axis Ax of each point in the substantially cylindrical region 14b is monotonously increased toward the front of the lamp, and thus the reflector 14 is formed. In this case, it is possible to prevent undercutting from occurring, thereby eliminating the need to provide a slide mechanism or the like in the mold structure for molding the reflector 14. In particular, in the present embodiment, since the draft angle at the rear end position of the substantially cylindrical region 14b is set to a value of about 3 °, the moldability of the reflector 14 can be sufficiently improved.

  Furthermore, in the vehicular lamp 10 according to the present embodiment, since the plurality of groove portions 14g extending in the front-rear direction of the lamp are formed as the light diffusion structure in the substantially cylindrical region 14b, the front and rear of the lamp due to the shape of the substantially cylindrical region 14b itself. In addition to the light diffusion action in the direction, the light diffusion action in the circumferential direction by these grooves 14g can be obtained, so that the translucent cover 16 is locally heated by the light from the light source 12a reflected by the substantially cylindrical region 14b. It can suppress very effectively.

  In the above-described embodiment, the reflector main body 14A and the peripheral wall 14B constituting the reflector 14 are described as being integrally formed. However, as shown in FIG. 6, the front end outer peripheral edge of the reflector main body 14A. It is also possible to employ a configuration in which the outer peripheral edge of the rear end of the peripheral wall 14B is fixed by ultrasonic welding or the like. Even in this case, the same effects as those of the above embodiment can be obtained. Further, even when the reflector main body 14A and the peripheral wall 14B are not connected and fixed in this manner, the reflector main body 14A and the peripheral wall 14B are fixed to other members (for example, a lamp body). It is also possible to configure so as to be held in a predetermined positional relationship, and even in this case, it is possible to obtain the same operational effects as in the above embodiment.

  In the above-described embodiment, the inner peripheral surface of the peripheral wall 14B of the reflector 14 has been described as being set as a substantially cylindrical region 14b over the entire periphery. However, for example, as shown in FIG. In the case where a region of more than a half circumference on the peripheral surface is set as the substantially cylindrical region 14b, the surface shape of the substantially cylindrical region 14b is set to the same surface shape as in the above embodiment, thereby Similar effects can be obtained.

  In the above embodiment, the reflecting surface 14a of the reflector main body 14A has a plurality of reflecting elements 14s formed concentrically, but a plurality of reflecting elements having different shapes are formed. Even when such a reflective element is not formed, the same effect as that of the above embodiment can be obtained.

  Furthermore, in the said embodiment, although demonstrated as what the translucent cover 16 was formed in the through shape, also when the lens element is formed in this translucent cover 16, the effect similar to the said embodiment is demonstrated. Can be obtained.

  In the above embodiment, the vehicular lamp 10 is described as being a backup lamp. However, even when the vehicular lamp 10 is another type of vehicular lamp (for example, a tail lamp, a turn signal lamp, a fog lamp, a head lamp, etc.) By adopting the same configuration as that of the above embodiment, the same effect as that of the above embodiment can be obtained.

The front view which shows the vehicle lamp which concerns on one Embodiment of this invention It is a sectional side view which shows the said vehicle lamp, Comprising: The figure which shows the optical path of the light reflected on the reflective surface of the reflector main body It is a sectional side view which shows the said vehicle lamp, Comprising: The figure which shows the optical path of the light reflected on the internal peripheral surface of a surrounding surface wall The graph which shows the result of the test done in order to confirm the effectiveness of employ | adopting the structure of the vehicle lamp which concerns on the said embodiment. The graph which shows the result of having done the same test about the vehicle lamp which concerns on a comparative example The same figure as FIG. 3 which shows the modification of the said embodiment. The same figure as FIG. 1 which shows the other modification of the said embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Vehicle lamp 12 Light source bulb 12a Light source 14 Reflector 14A Reflector main body 14B Perimeter wall 14a Reflective surface 14b Substantially cylindrical area 14c Valve insertion hole 14g Groove part 14s Reflective element 16 Translucent cover A Optical axis vicinity area Ax Optical axis

Claims (4)

A light source disposed on an optical axis extending in the front-rear direction of the lamp, a reflector having a reflecting surface that reflects light from the light source forward, and a translucent cover disposed in front of the reflector. ,
The reflector has a peripheral wall extending forward from the outer peripheral edge of the front end of the reflector body forming the reflective surface, and a region of at least a half circumference on the inner peripheral surface of the peripheral wall is centered on the optical axis. In the vehicular lamp set as a substantially cylindrical region having a substantially circular optical axis orthogonal cross-sectional shape,
A vehicular lamp, wherein a cross-sectional shape of the substantially cylindrical region along a plane including the optical axis is set to a curved shape that is convex toward the optical axis.   The vehicular lamp according to claim 1, wherein the radius from the optical axis of each point in the substantially cylindrical region is set so as to monotonously increase toward the front side of the lamp.   The vehicular lamp according to claim 1, wherein a light diffusion structure is provided in the substantially cylindrical region.   4. The vehicular lamp according to claim 3, wherein the light diffusion structure includes a plurality of grooves extending in the front-rear direction of the lamp.

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