Low weight tube fin heat sink
The invention provides a lighting device comprising a light source and a heat sink ( 200 ). The heat sink ( 200 ) is configured to dissipate thermal energy from the light source when in operation. The heat sink comprises a plurality of pin-shaped fins ( 210 ) and a support ( 220 ), wherein each fin ( 210 ) has a fin height (h) relative to the support ( 220 ), a bottom part ( 213 ) associated with the support ( 220 ) and a top part ( 214 ), a cross-section having a first width (d 1 ) and a second width (d 2 ) having a ratio d 1 /d 2 selected from the range of 1.2-10, and a first width axis, wherein the first width axes of the pin-shaped fins ( 210 ) are arranged parallel, and wherein the pin-shaped fins ( 210 ) are hollow over at least part of their fin height (h).
1. A heat sink comprising a plurality of pin-shaped fins and a support, wherein each fin has a fin height relative to the support, a bottom part associated with the support and a top part, a cross-section having a first width (d 1 ) and a second width (d 2 ) having a ratio d 1 /d 2 selected from the range of 1.2-10, and a first width axis, wherein the first width axes of the pin-shaped fins are arranged parallel, and wherein the pin-shaped fins are hollow over at least part of their fin height, wherein each pin-shaped fin comprises a fin wall with the fin wall defining a cavity within the pin-shaped fin having a cavity height, wherein the cavity has a cavity cross-section with a cavity cross-sectional area, wherein over at least part of the cavity height the cavity cross-sectional area reduces in a direction from the top part to the bottom part.
2. The lighting device comprising a light source and a heat sink according to claim 1 , wherein the heat sink is configured to dissipate thermal energy from the light source when in operation.
3. The lighting device according to claim 2 , wherein the plurality of pin-shaped fins are arranged in an array having one or more pitches selected from the range of 1.2*d1-6*d1.
4. The lighting device according to claim 2 , wherein the top parts of the pin-shaped fins are closed.
5. The lighting device according to claim 2 , wherein pin-shaped fins have a height in the range of 0.5-100 cm.
6. The lighting device according to claim 2 , wherein the heat sink comprises a support structure associated with the top parts of the plurality of pin-shaped fins.
7. The lighting device according to claim 2 , wherein the pin-shaped fins are over at least part of their fin height filled with a thermally conductive material.
8. The lighting device according to claim 2 , wherein the pin-shaped fins are arranged in a hexagonal array.
9. The lighting device according to claim 2 , wherein the lighting device comprises a floodlight.
10. The lighting device according to claim 2 , wherein the heat sink is configured to allow during operation of the lighting device an air flow between the pin-shaped fins in a direction parallel to the first width axes.
11. The lighting device according to claim 2 , wherein the pin-shaped fins comprise a material selected from the group consisting of aluminum, magnesium, copper, gold, silver, and an alloy comprising one or more of the aforementioned materials.
12. The lighting device according to claim 2 , wherein the pin-shaped fins have a cross-sectional shape selected from the group consisting of an oval, a rectangle, and a rhombus.