JP2008226716A - Vehicular lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular lamp capable of securing predetermined illumination luminous energy by suppressing temperature rise of an LED by enhancing a heat radiation property of self-heat generation of the LED while keeping small size and light weight, and thereby suppressing degradation of luminous efficiency of the LED, in a vehicular lamp using an LED as a light source. <P>SOLUTION: A lamp chamber is formed with a front cover 8 having a lens part 7, and a housing 5, and a metal substrate 4 with the LED 2 used as a light source mounted thereon is supported in the lamp chamber. Heat generating in lighting the LED is diffused into the lamp chamber from a surface of the metal substrate 4, and the heat diffused into the lamp chamber is diffused by a convection flow passing through a first free space 20, a gap space 22 and a second free space 19 constituting the lamp chamber, and radiated to the outside of this lamp through the housing 5 and the front cover 8 in the meantime. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicular lamp using an LED as a light source.

  Conventionally, a main component is an LED, a board on which the LED is mounted, a housing that houses the board on which the LED is mounted, and a lens that is disposed in front of the LED and controls light distribution from the LED. The following lamps have been proposed.

  As shown in FIG. 3, a heat transfer insulating sheet 31 for securing insulation with the metal substrate 30 is fixed on the metal substrate 30, and the heat transfer insulating sheet is fixed on the heat transfer insulating sheet 31. The LED main body 32 is mounted in a state in which the electrode terminal is connected to the conductive portion formed in 31, and the LED lamp 33 is formed.

  Then, the LED lamp 33 is assembled to the radiating fin structure 34 to form an LED lamp assembly 35. The LED lamp assembly 35 includes a light emitting portion 36 of the LED lamp 33 and a radiating fin 37 of the radiating fin structure 34, respectively. The light source attachment part 39 of 38 is attached so that it may be located inside and the outside, the lens 40 is arrange | positioned ahead of the light emission part 36 of the LED lamp 33, and the vehicle lamp 41 is formed.

  In the vehicular lamp 41 having the above-described configuration, the heat generated by the lighting of the LED main body 32 is transferred to the metal substrate 30 through the heat-conductive insulating sheet 31, and the heat-radiating fin structure 34 has good thermal conductivity and efficiency. Heat is transferred and radiated from the radiating fin structure 34 to the outside.

For this reason, the heat radiation efficiency with respect to the heat generation of the LED main body 32 is always stably obtained at a high level, and the illumination quality including the optical performance and the lighting life of the LED main body 32 can always be maintained at a high level. (For example, refer to Patent Document 1).
JP-A-2005-71818

  By the way, the heat radiation fin structure 34 constituting the vehicle lamp has a higher heat radiation efficiency and a better heat radiation effect as the heat radiation area of the entire surface of the portion in contact with the outside air of the heat radiation fin structure 34 is larger. That is, the size of the radiating fin structure 34 is related to the radiating efficiency. However, as the radiating fin structure 34 becomes larger, the entire vehicle lamp 41 becomes larger and the weight also increases. Therefore, it is conceivable that the degree of freedom in designing the dimensions of the radiating fin structure 34 cannot be ensured due to the mounting space of the vehicular lamp 41 and restrictions on the weight, and sufficient heat radiation efficiency cannot be obtained.

  Therefore, the present invention was devised in view of the above problems, and the object of the present invention is to improve the heat dissipation of self-heating of the LED while maintaining the small size and light weight in the vehicle lamp using the LED as a light source. Is to provide a vehicular lamp that can suppress a temperature rise of the LED and thus suppress a decrease in the light emission efficiency of the LED and secure a predetermined amount of irradiation light.

  In order to solve the above-described problem, the invention described in claim 1 of the present invention is such that a lamp chamber sealed by a front cover having a lens portion and a housing is formed, and at least an LED serving as a light source is mounted in the lamp chamber. The board is supported by a vehicle lamp, wherein two free spaces in contact with the surface of the board are formed on each surface side of the board, and the two free spaces are formed on the front cover and the It is connected via the clearance space formed in the clearance gap of the junction part of a housing, and the edge part of the said board | substrate.

  The invention described in claim 2 of the present invention is characterized in that, in claim 1, the substrate is a metal substrate made of a metal of aluminum or copper.

  Further, in the invention described in claim 3 of the present invention, in any one of claims 1 and 2, the LED is a surface-mounted LED that emits white light or light having a color tone close to white. It is characterized by.

  In the vehicular lamp of the present invention, a lamp chamber is formed by a front cover having a lens portion and a housing, and a substrate on which an LED serving as a light source is mounted is supported in the lamp chamber. Heat generated when the LED is lit is dissipated from the substrate into the lamp chamber, diffused by convection through the first free space, the gap space, and the second free space constituting the lamp chamber, and through the housing and the front cover. Released outside the lamp.

  Therefore, even if the vehicular lamp is small and light, the heat dissipation of the self-heating of the LED can be enhanced, and thus the temperature rise of the LED is suppressed and the decrease in the luminous efficiency of the LED is suppressed. As a result, it is possible to ensure a predetermined amount of irradiation light.

  Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIG. 1 and FIG. 2 (the same parts are denoted by the same reference numerals). The embodiments described below are preferred specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention is particularly limited in the following description. Unless stated to the effect, the present invention is not limited to these embodiments.

  FIG. 1 is a sectional view of an embodiment of a vehicular lamp according to the present invention. The vehicular lamp 1 mainly includes an LED 2 serving as a light source, a metal substrate 4 on which the LED 2 and the socket connector 3 are mounted, a housing 5 for fixing the metal substrate 4, a reflector 6 for directing light from the LED 2 in the irradiation direction, and a direct light from the LED 2. A front cover 8 having a lens portion 7 that collects the light and the light reflected by the reflector 6 and emits the light toward the irradiation direction is provided.

  The LED 2 is a surface mount type, and the blue LED element is a resin made of a translucent resin mixed with a phosphor that converts the wavelength to yellow light that is excited by the blue light emitted from the blue LED element and becomes a complementary color of blue. The white light is sealed by the additive color mixture of yellow light, which is wavelength-converted by exciting part of the blue light emitted from the blue LED element, and blue light emitted from the blue LED element. It is a white LED that emits.

  In addition, by using a phosphor which is a mixture of two types of phosphors that are excited by blue light and convert wavelengths into green light and red light, part of the blue light emitted from the blue LED element is phosphor. It is also possible to obtain white light by additive color mixing of green light and red light whose wavelengths are converted by exciting the blue light emitted from the blue LED element.

  There is also a method of obtaining white light by a combination of an ultraviolet LED element and a phosphor. It uses ultraviolet light emitted from the ultraviolet LED element by using a mixture of three types of phosphors that are excited by the ultraviolet light emitted from the ultraviolet LED element and convert the wavelengths of the light into blue light, green light, and red light, respectively. White light is obtained by additive color mixture of blue light, green light, and red light whose wavelengths are converted by exciting the phosphor.

  In any case, in the LED 2, the type, quantity, combination, type of phosphor, presence / absence of the phosphor, and the like of the LED element are determined based on required optical, electrical, and structural specifications.

  The metal substrate 4 is made of a metal material such as aluminum or copper, a heat conductive insulating film is formed on one surface, a circuit pattern by a metal thin film is formed thereon, and further on the portion excluding the electrode pad. Silk printing with white ink is applied. Note that the heat conductive insulating film, the circuit pattern, and the white ink are not shown.

  Then, the LED 2 and the socket connector 3 in which the respective electrodes and connector pins are connected to the electrode pads of the metal substrate 4 are mounted on the metal substrate 4, and the metal substrate 4 on which the LED 2 and the socket connector 3 are mounted is mounted on the housing 5. It is placed on the provided rib 16 and fixed to the housing 5 with screws 9.

  On the metal substrate 4 fixed to the housing 5, a reflector 6 having a light guide hole 10 and a reflecting surface 11 made up of a part of a substantially inverted conical surface rising from the light guide hole 10 is disposed. Ten inner peripheral surfaces 12 are positioned so as to surround the LED 2.

  Note that at least the reflection surface 11 of the reflector 6 is made of a metal reflection film such as aluminum, silver, or chromium.

  Further, a front cover 8 is disposed so that the meniscus concave lens portion 7 is positioned above the LED 2 and the reflector 6, and the end of the front cover 8 and the end of the housing 5 are welded to fix the front cover 8 to the housing 5. Has been.

  As a result, the metal substrate 4 on which the LED 2 and the socket connector 3 are mounted and the reflector 6 are supported in the lamp chamber formed by the housing 5 and the front cover 8. Then, the plug connector 13 is fitted into the socket connector 3, and the cord 14 extended from the socket connector 3 is pulled out to the outside through a bush 15 attached to the housing 5.

  In the vehicular lamp having the above-described configuration, the direct light reaching the inner surface of the lens portion 7 of the front cover 8 out of the light emitted from the LED 2 and passing through the light guide hole 10 of the reflector 6 and the light emitted from the LED 2 and the reflector 6. Of the light that passes through the light guide hole 10, the reflected light that is reflected by the reflecting surface of the reflector 6 and reaches the inner surface of the lens portion 7 of the front cover 8 is both condensed by the lens portion 7 and irradiated to the outside. .

  By the way, the heat generated when the LED 2 is turned on moves to the metal substrate 4 and is conducted through the metal substrate 4 to reach the surface of the metal substrate 4. At this time, an ink layer is formed on the first surface 17 on the side of the metal substrate 4 on which the LED 2 is mounted, and most of the heat is a surface on which the LED 2 is mounted. Are dissipated into the air from the opposite second surface 18.

And the 2nd free space enclosed by the housing 5 exists in the 2nd surface 18 side with much heat dissipation of the metal substrate 4. FIG. The second free space 19, there is a volume of about 3.2 cm ³ volume of metal substrate 4 to around 0.7 cm ^3, a volume of 4.5 times the volume of metal substrate 4. Therefore, the metal substrate 4 can ensure sufficient heat dissipation by dissipating the heat conducted to the metal substrate 4 from the second surface 18 into the second free space 19.

  Further, a first free space 20 surrounded by the front cover 8 exists on the side of the first surface 17 on which the LED 2 is mounted on the metal substrate 4, and the first free space 20 and the second free space 20 described above are present. As shown in the top view with the front cover 8 removed in FIG. 2, the free space 19 is provided via a gap space 22 provided between the welded portion 21 between the housing 5 and the front cover 8 and the edge of the metal substrate 4. Connected.

  Therefore, returning to FIG. 1, the heat transferred from the second surface 18 of the metal substrate 4 to the air in the second free space 19 is transferred into the first free space 20 through the gap space 22. Thus, the heat dissipated from the first surface 17 is also dissipated into the first free space 20. Thereafter, the heat in the first free space 20 moves to the second free space 19 through the gap space 22.

  Thus, the heat dissipated from both surfaces of the metal substrate 4 is convected through the first free space 20, the gap space 22, and the second free space 19 in the lamp chamber formed by the housing 5 and the front cover 8. In the meantime, it is discharged to the outside of the lamp through the housing 5 and the front cover 8. Thereby, further heat dissipation can be ensured.

  As a result, even if the vehicular lamp using the LED as a light source is small and lightweight, the heat dissipation of the self-heating of the LED can be improved, and thus the temperature rise of the LED is suppressed and the decrease in the luminous efficiency of the LED is suppressed. As a result, it is possible to secure a predetermined irradiation light amount.

It is sectional drawing of embodiment of the vehicle lamp of this invention. It is a top view concerning the embodiment of the vehicular lamp of the present invention. It is sectional drawing which shows a prior art example.

Explanation of symbols

1 Vehicle lamp 2 LED
3 socket connector 4 metal substrate 5 housing 6 reflector 7 lens portion 8 front cover 9 screw 10 light guide hole 11 reflecting surface 12 inner peripheral surface 13 plug connector 14 cord 15 bush 16 rib 17 first surface 18 second surface 19 first Second free space 20 First free space 21 Welded portion 22 Gap space

Claims (3)

  A vehicle lamp in which a lamp chamber sealed by a front cover having a lens portion and a housing is formed, and a substrate on which at least an LED serving as a light source is mounted is supported in the lamp chamber, and each surface side of the substrate Are formed with two free spaces in contact with the surface of the substrate, and the two free spaces are formed in a gap between the front cover and the housing, and a gap between the edges of the substrate. A vehicular lamp characterized by being connected to each other.   The vehicular lamp according to claim 1, wherein the substrate is a metal substrate made of one of aluminum and copper.   The vehicular lamp according to claim 1, wherein the LED is a surface-mounted LED that emits white light or light having a color tone close to white.

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