FIELD OF INVENTION
The present invention proposes a cooling system for an LED headlamp used in a three-wheeler.
BACKGROUND
A headlamp is a light fixed to the front of a vehicle to illuminate the road ahead. A variety of headlamps is created based on the need for colour, intensity of the beam, compatibility, time of usage, etc. The headlamp is designed based on International styling and U.S. headlamp styling. The light sources used for the illumination evolved from Tungsten light to LED. The light beam travel length control can also be altered by different lighting systems like headlamp leveling systems. Directional headlamps. Advanced front lighting system (AFS), Automatic beam switching. Intelligent Light System, Adaptive high beam. Glare-free high beam and pixel light.
For energy efficiency and low power consumption, LED lamps are used in the present lighting arrangements for two-wheeler and three-wheeler, headlights and side indicators. As the technology shifts from conventional headlamp to LED headlamp, heating becomes a major concern for LED headlamp, which is solved in a diverse fashion.
There are two conventional ways being used to solve the heating problem. Firstly, the heating of LED light source is solved by providing an LED mounted heat sink. In which, the heat sink facilitates mounting for LED base and expose it to the environment for cooling. In general, the heat sink is made of Aluminium, Copper, or other moderate thermal conductivity material. The major drawback being the usage of heavy material in the area of LED holder makes it bulky and thermally inefficient cooling, in a high range of ambient temperature. Moreover, the thermal resistance is too high to provide effective cooling. The said type of cooling system cannot be used for high power source cooling, without occupying a large surface area. The system assembling and servicing become difficult if more surface area is added. Thus, leads to structural failure of the headlamp housing.

Secondly, the LED is mounted on the heat sink, which is incorporated with a fan. In this type of cooling system, an additional fan is employed with the LED mounted heat sink for forced convection. The higher power consumption by the fans makes the system less reliable. The heavy material usage in the area of LED holder makes it bulky and thermally inefficient cooling, in a high range of ambient temperature. The system occupies more surface area for effective cooling which subsequently establish difficulties in assembling and servicing the system.
In the conventional way of cooling, the drawbacks observed are,
1. Heavy heat sinks are used to get effective cooling which results in occupying more surface area;
2. Increase in surface area leads to structural failure to lamp housing;
3. Consequently, increases the difficulty of assembling and servicing of the system;
4. Inefficient cooling at higher temperature of ambient;
5. The thermal resistance of the conventional cooling system is very high;
6. For high power source the conventional cooling system is not suitable; and
7. The inclusion of fan for forced convection leads to more power consumption and reduces the reliability of the system.
The above-mentioned drawbacks are eliminated in the proposed system by providing a heat pipe assembly, which connects the LED source and heat sink. The heat transfer is done by forced convection. The cooling arrangement provided of the present invention helps in achieving 15 to 25 degree Celsius reduction in temperature around the LED base region.
DISCUSSION OF PRIOR ART
US20090195159 titled "LED cooling system" describes the LED chip with a high power LED cooling system attachment. The cooling system consists of a heat radiator, fan, and an attached power supply. By spring loaded posts the components are interconnected to absorb temperature that built-up. For monitoring the temperature, a thermocouple device is incorporated. The LED chip

shuts off before reaching a critical temperature. Compared to the proposed system, the present system has separate heat radiator, fan, and attached power supply. Thus assembling becomes complicated, and the attachment for heat transfer makes the system heavy.
US20150016123 titled "Automotive LED Headlight Cooling System" describes a lighting assembly that contains a cooling system designed to enable the dissipation of the heat generated. The cooling system is designed as gravity feed system, which does not require a powered fluid pump. The light source is made of multiple LEDs, which is mounted on a printed circuit board (PCB). The PCB is placed vertically onto the evaporator, which allows cooling of vertical alignment of the PCB. The vertical alignment of the PCB makes a horizontal projection of light as in an automotive headlight application. In this invention, a transfer pipe and the radiators are provided for heat transfer. The construction is different from proposed invention.
US7204624 titled "Headlamp for a two-wheeled vehicle" describes the novel design of a headlamp, which is used for a two-wheeled vehicle. The invention provides a design of the headlamp for the two-wheeled vehicle to improve visibility and increases feasibility while designing the front cover of a vehicle body. The headlamp is placed in the front body of the vehicle, in such a way to get forced air-cooling while driving. The invention mainly focuses on the shape of the headlamp.
Tenth International Heat Pipe Symposium titled "Development of Cooling System of LED Headlamp for Vehicle Using Vapor Chamber Type Heat Pipe"
describes the cooling system for an LED headlamp for a vehicle, which uses a vapor chamber type of heat pipe. The thermal properties of an LED headlamp cooling system are analyzed. A study on the vapor-chamber type heat pipe is done by checking the thermal resistance of existing and present cooling system. The working fluid is distilled water with a charging ratio of 50, 70, and 100%. The heat transfer takes place by transferring heat to the chamber that has the working fluid. In this case, the Vapor Chamber is provided to absorb heat from LED. The

heat pipe connected with Vapor Chamber transfers heat from evaporating section to condensing section, and working fluid come to a condensed state. The present invention differs from the proposed system by the type of cooling system and constructional difference.
The proposed cooling system of LED headlamp works on the principle of heat transfer through a phase change. A heat pipe is used in combination with an aluminium heat sink to dissipate the heat. The shape of the heat pipe can be straight or with a 3-D bend having a cross-section in any of the following forms, circular, elliptical, rectangular or square. The heat sink is positioned in such a way to provide forced convection when the vehicle is in motion. The design is suitable for varying ambient temperature range.
SUMMARY OF THE INVENTION
In the present invention, an LED light mounted heat pipe is used. The system works based on the principle of heat transfer through a phase change. The heat pipe contains fluids like methanol, ethanol, ammonia or water which has a low boiling temperature at a vacuum pressure that undergoes a cyclic phase transfer inside the tube. The first phase transfer happens at the LED base from liquid to gas. While the evaporation and condensation happen at the air cooled system from the gas to a liquid phase. The heat pipe is used in combination with an aluminium heat sink to dissipate the heat. The heat sink is placed effectively to provide forced convection during the running condition of the vehicle. The same design is suitable for different ambient temperature range. The heat pipe can be straight in shape or with a 3-D bend having either circular or elliptical or rectangular or square cross-section.
The device consists of an LED base, the heat pipe, an LED holder, an LED holder seal, an LED holder pin, a heat sink, and a screw. The LED base provides a base to the LED and an electronic component. The LED base transfers heat to the heat pipe. The heat pipe functions as a heat carrier from the LED base to heat sink and offers a flexible heat routing from a source to sink. The LED holder provides the base and structural support to the heat pipe for proper functioning. The LED

holder seal prevents the device from dust and water entering inside the lamp housing. The LED holder pin locks the LED holder with the lamp housing, and the heat sink dissipates the heat to the environment. The screw facilitates the interface between the heat pipe and heat sink.
An alternate method has the same arrangement that can be used without the heat sink. In another system, the same arrangement of the heat pipe of rectangular section is used. In yet another system, the similar arrangement of the heat pipe is used in a helical shape. The device can be used in three-wheeler LED headlamp and side indicator.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 illustrates a perspective view of the Vehicle with a headlamp and
cooling arrangement.
Figure 2 illustrates the direction of airflow when the three-wheeled vehicle is in
running condition.
Figure 3 illustrates a sectional view of the headlamp assembly taken along line A-
A in Figure 2.
Figure 4 illustrates the headlamp assembly with a cooling arrangement from the
backside.
Figure 5 illustrates the headlamp assembly with a cooling arrangement from the
front side.
Figure 6 illustrates the headlamp exploded front-side view with the cooling
arrangement.
Figure 7 illustrates the headlamp exploded backside view with the cooling
arrangement.
DETAILED DESCRIPTION OF ACCOMPANYING EMBODIMENTS
In the present invention. Figure 1 depicts the three-wheeler showing a mounting arrangement and orientation of headlamps enclosed with headlamp bezel. The headlamp bezel prevents the headlamp from the entry of water and other dust particles. The airflow into the headlamp enclosure is also guided by the headlamp

bezel. The headlamp described in the present invention is the LED-based headlamp, which includes one or more LEDs. The mounting and arrangement of LED headlamp at Right hand (RH) 1 side and left hand 3 (LH) side is shown in Figure 1. Similarly, the LED headlamp enclosure bezel is at right hand (RH) 2 side and left hand (LH) 4 side.
In the present invention. Figure 2 depicts the direction of airflow 5 when the three-wheeled vehicle is in running condition. A sectional line A-A 6 is drawn across the headlamp assembly. The effect of airflow into the headlamp assembly is described in the sectional drawing shown in forthcoming figure description.
In the present invention. Figure 3 shows a sectional view of the headlamp assembly taken along line A-A in Figure 2. Figure 3 depicts various components of the headlamp assembly of the present invention. The headlamp assembly includes a headlamp housing LH 10 that is disposed within the headlamp bezel LH 4. The headlamp housing accommodates an LED holder 11 that is capable of holding one or more LEDs. For example, the LED holder is capable of holding three LEDs in three different directions, i.e., towards the front, RH and LH sides of the vehicle. The LED holder 11 is provided with at least one LED holder seal 12 to prevent entry of water and other dust particles from the rear side of the headlamp assembly. A heat sink 7 is disposed upwardly beneath the LED headlamp bezel (LH 4 and RH) to effect the transfer of heat between the headlamp housing (LH 10 and RH) and the atmosphere. For example, the heat sink 7 ensures that the headlamp housing is not affected by the heat generated by the LEDs, as the heat sink discharges the heat to the atmosphere and enable cooling of the LED headlamp assembly.
In the present invention. Figure 4 shows the arrangement of a heat pipe 8 in the headlamp assembly. The heat pipe enables transfer of heat generated from the LEDs to the heat sink 7. The heat pipe can be straight in shape or with a 3-D bend having either circular or elliptical or rectangular or square cross-section. For example, one end of the heat pipe 8 is connected to the LED holder 11, and the

other end is connected to the heat sink 7. Further, the LED holder pin 13 enables mounting of the LED holder to the headlamp housing 10.
In the present invention, Figure 5 illustrates the headlamp assembly with a cooling arrangement from the front side. The heat pipe enables heat transfer from LED to the heat sink. The LED headlamp housing Lens 16 is mounted on the LED headlamp housing 10.
In the present invention. Figure 6 illustrates the headlamp exploded view with a cooling arrangement from the front side. The exploded view shows the position of the LED headlamp housing Lens 16 mounted on the LED housing. It shows the position of the LED holder 11 from a front view. The heat sink 7 mounted on the LED headlamp holder is also viewed from the exploded front view.
In the present invention. Figure 7 illustrates the headlamp exploded view with a cooling arrangement from the backside. This figure depicts the essential component present in the LED headlamp. The device comprises an LED base 25, the heat pipe 8, the LED holder 11, the LED holder seal 12, the LED holder pin 13, the heat sink 7 and a Screw-M5 22. The functionality and the purpose of these components described in this section. Wherein, the LED base 25 facilitates mounting of LED and electronic component. It transfers the heat generated by LED to the heat pipe 8. Moreover, it is pasted or screwed on the heat pipe to minimize the thermal resistance. The heat pipe 8 carries the heat generated at the LED base 25 to the heat sink 7. Generally, it facilitates routing heat path from the LED source to the heat sink 7 and provides high thermal conductivity compared to any conventional material. The LED holder 11 is made of high thermal resistance plastic material. It provides base support to the heat pipe 8 in an area of luminosity. It also guides the LED beam projection in a particular direction for desired light pattern it provides ease of assembly and service. The LED holder seal 12 is made of thermal resistance rubber material, which is used for sealing purpose. Use of this seal makes the system dust and waterproof. The LED holder pin 13 locks the LED holder 11 with the lamp housing. It facilitates ease of

assembly and removal of LED holder 11. The heat sink 7 is made of Aluminium/Copper/steel material to dissipate the heat to the environment. It is positioned on top of lamp housing to have forced cooling during running condition of the vehicle. It provides minimal thermal resistance. The positioning of a heat sink on lamp housing avoids the structural failure of headlamp housing. The Screw-M5 22, which is the suitable size screw, is used to fasten the heat pipe 8 and heat sink 7. Alternatively, a press fit or pasting with thermal grease can be used for the same purpose.

WE CLAIM
1. A highly reliable and efficient LED headlamp 1, 3 (RH and LH side) cooling system for a three-wheeler having (a) a Heat sink 7, (b) a Heat pipe 8, (c) an LED headlamp housing 10, (d) an LED holder 11, (e) an LED holder seal 12, (f) an LED holder pin 13, (h) LED headlamp Housing Lens 16, (i) an LED headlamp bezel, (j) a Screw-M5 22 and (k) an LED base 25 wherein: (i) The LED headlamp housing 10 (LH side) is protected by the LED
headlamp Housing Lens 16 (LH side) and the LED headlamp bezel
on LH side 4 and RH side 2); (ii) The LED base 25 facilitates mounting of LED and electronic
component, and transfers heat generated by the LED to the Head
pipe 8 to minimize the thermal resistance; (iii) The Heat sink 7 is for forced cooling during running condition; (iv) The Heat pipe 8 carries the heat generated at the LED base 25 to
the heat sink 7; (v) The LED holder 11 provides base support to the heat pipe 8 in an
area of luminosity; (vi) The LED holder seal 12 protects the lamp housing from dust and
water; (vii) The LED holder pin 13 locks the LED holder 11 with the lamp
housing 10 (LH side); and (viii) The Screw-M5 22 fastens the heat pipe 8 and the heat sink 7.

2. The highly reliable and efficient LED headlamp 1, 3 (RH and LH side) cooling system of Claim 1 wherein, the heat pipe 8 facilitates the routing of heat path from LED source to the heat sink 7 and provides high thermal conductivity than any conventional material.
3. The highly reliable and efficient LED headlamp 1, 3 (RH and LH side) cooling system of Claim 1 wherein, the LED holder 11 is made of high thermal resistance plastic material for ease of assembly and service.
4. The highly reliable and efficient LED headlamp 1, 3 (RH and LH side) cooling system of Claim 1 wherein, the LED holder 11 directs the LED beam projection in a particular direction for desired light pattern.
5. The highly reliable and efficient LED headlamp 1, 3 (RH and LH side) cooling system of Claim 1 wherein, the LED holder seal 12 is made of thermal resistance rubber material for a dust-free and waterproof system.
6. The highly reliable and efficient LED headlamp 1, 3 (RH and LH side) cooling system of Claim 1 wherein, the LED holder pin 13 locks the LED holder 11 with lamp housing 10, thus facilitates easy assembly and removal of the LED holder 11.
7. The highly reliable and efficient LED headlamp 1, 3 (RH and LH side) cooling system of Claim 1 wherein, the heat sink 7 is made from any of the following material. Aluminium, Copper, Steel to dissipate heat to the environment and is positioned on top of lamp housing 10 which prevents structural failure of headlamp housing 10, also assists in minimising the thermal resistance.
8. The highly reliable and efficient LED headlamp 1, 3 (RH and LH side) cooling system of Claim 1 wherein, the Screw-M5 22 of suitable size fastens the heat pipe 8 and the heat sink 7 and, an alternate being a press fit or pasting with thermal grease for the fastening.

9. The highly reliable and efficient LED headlamp 1, 3 (RH and LH side) cooling system of Claim 1 wherein, an alternate construction has the same arrangement with any of the modifications like, exclusion of the heat sink 7, a rectangular section of the heat pipe 8 and a helical form of the heat pipe 8.
10. A method of the highly reliable and efficient LED headlamp 1, 3 (RH and LH side) cooling system having (a) a Heat sink 7, (b) a Heat pipe 8, (c) an LED headlamp housing 10, (d) an LED holder 11, (e) an LED holder seal 12, (f) an LED holder pin 13, (h) LED headlamp Housing Lens 16, (i) an LED headlamp bezel, (j) a Screw-M5 22 and (k) an LED base 25 comprising the steps of:
(i) Transferring the heat generated from the LED to a heat pipe 8 by the LED base 25 which is pasted and sometimes screwed on the heat pipe 8 in order to minimise the thermal resistance;
(ii) Routing the heat path by the heat pipe 8 to the heat sink 7 which is fastened together using the Screw-M5 22, and providing high thermal conductivity than any other conventional material;
(iii) Providing base support to the heat pipe 8 by the LED holder 11 in an area of luminosity and guiding the LED beam projection in a particular direction for the desired light pattern, thus leading for an ease of assembly and service;
(iv) Preventing the system from dust and water by introducing the LED holder seal 12;

(v) Locking the LED holder 11 with lamp housing 10 (LH side) using the LED holder pin 13; and
(vi) Dissipating of heat to the environment by the heat sink 7 which is positioned on top of the lamp housing 10 for forced cooling when the vehicle is in running condition, thus positioning results in minimal thermal resistance and preventing of structural failure of the headlamp housing 10.