Patent Application
20160208997
N/A
The present disclosure relates generally to a regulatable air duct to provide air to a vehicle headlamp, in particular engine throttle-responsive headlamp cooling.
In general, in an automotive headlamp using LEDs (light-emitting diodes), it is beneficial to manage the heat dissipated by the drive circuitry and by the LEDs themselves. Heat management approaches using large heat sinks or actively driven cooling fans are known, but these such components add weight, cost, restrict design space, and in the case of an actively driven fan can decrease overall robustness of the system. Software approaches to heat management are known such as programming the drive circuits to decrease power to lower the heat generated when temperature exceeding a pre-determined threshold is sensed, but this is also expensive.
The following vehicle lamps are known: U.S. Pat. No. 7,329,033 (Glovatsky); U.S. Pat. No. 6,497,507 (Weber); U.S. Pat. No. 6,447,151 (Jones); U.S. Pat. No. 7,478,932 (Chinniah); U.S. Pat. No. 6,676,283 (Ozawa); U.S. Pat. No. 6,595,672 (Yamaguchi); U.S. Pat. No. 6,071,000 (Rapp); U.S. Pat. No. 6,021,954 (Kalwa); U.S. Pat. No. 5,406,467 (Hashemi); and Application US 2011/0310631 (Davis). In U.S. Pat. No. 7,329,033 (Glovatsky) it is known to provide cooling air to ducts arranged in a headlamp assembly using a forced convective flow shown in
A headlamp venting system is provided for a vehicle having a vehicle headlamp 30 configured to receive a light source 33, in which the venting system includes a vehicle air intake comprising an engine ducting 2 adapted to receive airflow from an air inlet 40 and conduct airflow in a flow direction 13 to a ducting outlet 42 which is coupled to the vehicle engine. A headlamp duct 28 is connected in fluid communication with the engine ducting 2 between the air inlet 40 and the ducting outlet 42. The headlamp duct 28 is adapted to receive airflow 13 from the engine ducting 2 and direct airflow to the vehicle headlamp 30. A valve 6 is disposed between the headlamp duct 28 and the engine ducting 2 and is displaceable between a first position and a second position, whereby in the first position valve 6 permits airflow to the headlamp duct 28 to be discharged toward the vehicle headlamp 30, and in the second position valve 6 occludes airflow to the headlamp duct 28 to a greater extent than in the first position. Thus, at low engine throttle valve 6 permits airflow to the headlamp duct 28 and at high engine throttle valve 6 is displaced to the second position.
Reference should be made to the following detailed description, read in conjunction with the following figures, wherein like numerals represent like parts:
For a thorough understanding of the present disclosure, reference should be made to the following detailed description, including the appended claims, in connection with the above-described drawings. Although the present disclosure is described in connection with exemplary embodiments, the disclosure is not limited to the specific forms set forth herein. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient. Also, it should be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
Applicant herein proposes an air flow system and method to use an airflow, advantageously using a passively regulated air flow, that avoids the need for a forced-air device such as a fan, and diverts some air from the engine air intake ducting. Another advantage of use of the proposed embodiment is that it can allow for a reduction in size and weight of a heat sink associated with an LED headlamp, and thus a reduction in cost.
The air flow solution proposed herein is useful not only in motor vehicles designed to travel on roads, but can advantageously be used in other vehicle applications such as trains, boats, tractors, off-road vehicles, snowmobiles, and the like.
Automotive design is often predicated on a consideration of a worst case scenario. In the case of excessive heat affecting an LED headlamp performance, this would assume such factors as a hot climate with maximum sunlight exposure, the headlamp's being on, the vehicle motor running and no external airflow, such as with a stationary, idling vehicle. It can be the case that once the vehicle is in motion, that additional airflow would help mitigate heat buildup. The present inventor herein recognized and expects that even a small amount of airflow, such as that corresponding to a vehicle speed exceeding 5 mph (or about 8 kmh) can help improve the thermal performance of an LED lighting system, for example by using air scoops under the chassis proximate the headlamps, thus solving a stagnant air problem, even when no special ducting system as hereinbelow described is used to direct air to the headlamp.
As background, it is conventionally known that, in general, an engine throttle is typically a butterfly valve, placed at the entrance of the intake manifold. The butterfly valve is also referred to as a throttle plate, which is a moving piece inside a throttle body. On many vehicles, the accelerator pedal motion is communicated via a throttle cable to activate the throttle linkages which move the throttle plate. In cars with electronic throttle control, an electric motor controls the throttle linkages and the accelerator pedal connects not to the throttle body but to a sensor, and this sensor sends the pedal position to an Engine Control Unit (ECU). The ECU determines the throttle opening based on accelerator pedal position and inputs from other engine sensors. When the driver presses on the accelerator pedal, the throttle plate rotates within the throttle body, opening the throttle passage to allow more air into the intake manifold, which is herein referred to, relatively, as a “high throttle” condition. Usually an airflow sensor measures this change and communicates with the ECU.
With reference to
Preferably valve 6 is advantageously located before the mass airflow sensor so that the vehicle computer can adjust for the changing amount of intake air (operation 16).
The light source is preferably a solid-state light source such as light emitting diode 33 (“LED”) attached to a printed circuit board (PCB) 32 that includes electronics controls and connections for driving and controlling the LED 33. In a known manner light emitted from LED 33 strikes optics such as reflector 34 which re-directs the light rays in the forward direction through a lens or lens cover 36. The LED 33 and PCB 32 are supported on heat sink 31 accommodated within housing 38. Heat sink 31 advantageously has heat exchange fins that extend into headlamp duct 28 for discharging heat generated by operation of LED 33. Heat sink 31 is constructed of material having a relatively high thermal conductivity. During operation of headlamp assembly 30, LED 33 generates heat and LED 33 and/or other electronic components may experience diminished performance if its or their respective maximum operating temperature is exceeded. To reduce the temperature of these components, heat sink 31 discharges heat into an airflow guided by headlamp duct 28.
Headlamp duct 28 is not required to be a channel completely bounded, as seen in cross-section, on all sides, such as a tube or closed rectangular cross-sectional shape. Headlamp duct 28 is sufficiently defined by one or more surfaces that guide airflow proximate the headlamp assembly 30 to interact with heat sink 31.
In alternate embodiments not illustrated, valve 6, rather than being the depicted valve that passively and mechanically responds directly to change in air pressure in the air intake duct, may be electronically controlled by an electronic sensor that is responsive to engine throttle speed or to air pressure, such as a sensor positioned in engine ducting 2.
The disclosed embodiment can be built as part of an Original Equipment Manufacturer (OEM) system or designed as a retrofit kit for vehicles in a similar manner to a cold air intake system, such as by splicing into the existing engine air ducting 2. In such a retrofit kit a headlamp duct 28 bearing a valve 6 would be provided; then a splice would be made by cutting into engine ducting 2 and attaching a proximal first portion of headlamp duct 28 at a suitable duct junction 5; and then one would position a distal second portion of headlamp duct 28 adjacent a heat-emitting portion of headlamp 30 such as adjacent heat sink 31.
While several embodiments of the present disclosure have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the functions and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the present disclosure. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the teachings of the present disclosure is/are used.
Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the disclosure described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, the disclosure may be practiced otherwise than as specifically described and claimed. The present disclosure is directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the scope of the present disclosure.
All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms.
The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, are understood to mean “at least one.”
The phrase “and/or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Other elements may optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified, unless clearly indicated to the contrary.
An abstract is submitted herewith. It is pointed out that this abstract is being provided to comply with the rule requiring an abstract that will allow examiners and other searchers to quickly ascertain the general subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims, as set forth in the rules of the U.S. Patent and Trademark Office.
An exemplary, non-limiting list of reference numerals used herein follows:
