Headlamp assembly having cooling channel

• US 20070121336A1
• Filed: 11/29/2005
• Published: 05/31/2007
• Est. Priority Date: 11/29/2005
• Status: Active Grant

• Current Assignee: Varroc Lighting Systems S.R.O. (Varroc Engineering Limited)
• Original Assignee: Visteon Global Technologies Incorporated (Visteon Corporation)
• Inventors: Lyon, Paul, Chinniah, Jeyachandrabose, Singh, Harvinder, Duszkiewicz, Alan, Tarne, James, Sayers, Edwin
• Granted Patent: US 7,478,932 B2
• Time in Patent Office: Days
• US Class Current: 362/507
• CPC Class Codes: F21S 41/143 the main emission direction of the LED being parallel to the optical axis of the illuminating device
• CPC Class Codes: F21S 45/33 specially adapted for headlamps
• CPC Class Codes: F21S 45/42 Forced cooling
• CPC Class Codes: F21S 45/43 using gas
• CPC Class Codes: F21S 45/47 Passive cooling, e.g. using fins, thermal conductive elements or openings
• CPC Class Codes: F21S 45/48 with means for conducting heat from the inside to the outside of the lighting devices, e.g. with fins on the outer surface of the lighting device
• CPC Class Codes: F21V 15/01 Housings, e.g. material or assembling of housing parts F21V15/02 takes precedence housings forming signs or letters G09F13/04
• CPC Class Codes: F21V 29/15 Thermal insulation
• CPC Class Codes: F21V 29/505 of reflectors
• CPC Class Codes: F21V 29/60 characterised by the use of a forced flow of gas, e.g. air
• CPC Class Codes: F21V 29/763 the planes containing the fins or blades having the direction of the light emitting axis
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

A headlamp assembly for a motor vehicle having a light source, a chamber that receives the light source and a cooling channel for removing heat from the chamber. A conductive wall and an insulating wall cooperate to define the chamber and the channel. The conductive wall has a substantially higher thermal conductivity than the insulating wall to promote the heat exchange between the chamber and the cooling channel and to reduce heat exchange between the cooling channel and the relatively hot engine compartment.

Claims

1. A headlamp assembly for a motor vehicle comprising:

a lens;

a conductive wall having a conductive wall inner surface and a conductive wall outer surface, the conductive wall inner surface cooperating with the lens to at least partially define a chamber that is generally fluidly isolated from the atmosphere;

a light source located within the chamber; and

an insulating wall having an insulating wall inner surface spaced apart from the conductive wall outer surface and cooperating to define a cooling channel therebetween to promote heat exchange between the chamber and the cooling channel, the cooling channel extending between an inlet and an outlet in fluid communication with the atmosphere;

wherein the conductive wall has a thermal conductivity that is substantially higher than that of the insulating wall to promote the heat exchange between the chamber and the cooling channel.

2. A headlamp assembly as in claim 1, wherein the insulating wall thermal conductivity is less than or equal to 5.0 W/(m·

K) and the conductive wall thermal conductivity is greater than or equal to 10.0 W/(m·

K).

3. A headlamp assembly as in claim 2, wherein the insulating wall thermal conductivity is less than or equal to 1.0 W/(m·

K) and the conductive wall thermal conductivity is greater than or equal to 20 W/(m·

K).

4. A headlamp assembly as in claim 3, wherein the insulating wall thermal conductivity is less than or equal to 0.5 W/(m·

K) and the conductive wall thermal conductivity is greater than or equal to 50 W/(m·

K).

5. A headlamp assembly as in claim 4, wherein the insulating wall thermal conductivity is less than or equal to 0.2 W/(m·

K) and the conductive wall thermal conductivity is greater than or equal to 50 W/(m·

K).

6. A headlamp assembly as in claim 1, wherein the conductive wall includes a base material and a plurality of conductive components supported by the base material.

7. A headlamp assembly as in claim 6, wherein the base material is a polymer.

8. A headlamp assembly as in claim 6, wherein the conductive components are of a material selected from the following group:

metal, metal alloy, silicon, and graphite

9. A headlamp assembly as in claim 1, wherein the conductive wall includes a conductive material selected from the following group:

metal, metal alloy, silicon, and graphite.

10. A headlamp assembly as in claim 9, wherein the insulating wall is of an insulating material selected from the following group:

glass, ceramic, and plastic.

11. A headlamp assembly as in claim 1, further comprising at least one divider extending into the cooling channel between the conductive wall and the insulating wall to define a plurality of cooling channel portions.

12. A headlamp assembly as in claim 11, wherein the at least one divider extends into the chamber from the conductive wall.

13. A headlamp assembly as in claim 1, wherein the inlet is located adjacent to a bottom portion of the headlamp assembly and the outlet is located adjacent to a top portion of the headlamp assembly.

14. A headlamp assembly as in claim 1, further comprising a thermoelectric device located in the conductive wall to promote the heat exchange between the chamber and the cooling channel.

15. A headlamp assembly as in claim 1, wherein the conductive wall and the insulating wall are generally equidistantly spaced from each other.

16. A headlamp assembly as in claim 1, further comprising a plurality of fins coupled to the light source to promote heat transfer from the light source to air in the chamber.

17. A headlamp assembly as in claim 16, further comprising a connector post extending from the conductive wall supporting the light source.

18. A headlamp assembly as in claim 17, wherein the fins and the connector post include a metal material.

19. A headlamp assembly as in claim 1, wherein the headlamp assembly includes a front portion exposed to the atmosphere and a rear portion exposed to an engine compartment.

20. A headlamp assembly as in claim 1, wherein the conductive wall at least partially defines a reflector.