Description:Complete Specification

The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed.
Field of the Invention
[0001] This invention is related to a piston of an engine with at least one integrated heat pipe of an internal combustion engine.

Background of the invention
[0002] Cooling in pistons is crucial for maintaining optimal engine performance. By dissipating excess heat effectively, cooling the pistons prevents overheating and reduces the risk of engine damage. Efficient cooling of pistons also improves lubrication, minimizes wear and tear, and enhances overall engine longevity, making it an essential component for reliable and efficient operation.

[0003] A US patent application US9470178 discloses an engine assembly. An engine cylinder head is provided. The engine cylinder head includes a portion of a first combustion chamber, an upper coolant core and a lower coolant core directing heat from the first combustion chamber and including a first coolant passage and a second coolant passage, the first coolant passage and the second coolant passage laying along a lateral axis, at least a portion of the first coolant passage separated from the second coolant passage via first and second walls.

Brief description of the accompanying drawing
[0004] Figure 1 illustrates a piston with a heat pipe integrated therein in accordance with one embodiment of the invention.

Detailed description of the embodiments
[0005] Figure 1 illustrates a piston 10 with a heat pipe 14 secured thereto, in accordance with an embodiment of the invention. The piston 10 comprises a top end portion 15 and a bottom end portion 12. The piston 10 comprises at least one heat pipe 14 secured to the bottom end portion 12 of the piston 10. The at least one heat pipe 14 comprises a hollow tube 15 filled with a working material that melts at a predefined temperature.

[0006] Further, the components of the piston 10 and working of the piston 10 with the heat pipe 14 secured thereto is explained in detail. According to one embodiment of the invention, the piston 10 comprises four integrated heat pipes 14 spread across the circumference of the bottom end portion 12 of the piston 10. The dimensions (size and shape) of the at least one heat pipe 14 is made to conform to the cut-section 16 present in the bottom end portion 12 of the piston 10. One end 14(a)/top portion of at least one heat pipe 14 is secured in a hot portion at the bottom end portion 12 of the piston 10 and an opposite end 14(b)/bottom portion is positioned away from the bottom end portion 12 of the piston 10 i.e.., opposite end of the heat pipe 14 and piston 10 interface and is colder than the top portion of the heat pipe 14.

[0007] The heat pipe 14 is closed at both ends before securing the at least one heat pipe 14 to the bottom end portion 12 of the piston 10. Each heat pipe 14 comprises a hollow tube 15 having a working material that changes its state on getting exposed to heat. Heat pipes 14 can transfer much higher heat for a given temperature gradient than the conventional metallic conductors. The heat pipe material has a low melting point and chosen from a group of materials comprising sodium, potassium, cesium and the like. However, the heat pipe material can be any other material, but not limited to the above materials, which changes its state to a vapor state when exposed to heat and back to its original state when cooled down.

[0008] The quantity and type of material filled in the heat pipe 14 is chosen based on at least one parameter, wherein the parameter is chosen from any one of the following comprising a wick volume, porosity, an evaporator volume, and a density variation during a phase change. The material converts into a vapor state upon receiving heat and dissipates the heat through a wick of the bottom portion 14(b) of the heat pipe 14 . The heat pipe material has a high thermal resistance up to the melting point and the heat is dissipated after that melting point.

[0009] A working methodology of the at least one heat pipe 14 is explained in detail. During the assembling process, the at least one heat pipe 14 is fitted within a cut-section 16 that is present at the bottom end portion 12 of the piston 10. As mentioned above, four integrated heat pipes 14 are fitted on across the circumference of the piston 10 bottom end portion 12, for dissipating heat from the piston bottom end portion 12 into the atmosphere. The heat pipe material present in the hollow tube 15 of the corresponding heat pipe 14 absorbs the heat from the bottom end portion 12 of the piston 10 and gets converts into a vapor state.

[0010] The converted vapor moves upwards towards the bottom portion 14(b) of the piston 10, away from the bottom end portion 12 of the piston 10 carrying the heat. At this position, the heat carried through the vaporized heat pipe material is dissipated into the atmospheric air and the heat pipe material is converted back to the original state, after cooling down at the bottom portion 140.

[0011] For instance, the heat pipe 14 has low melting point metallic fillers like sodium which helps with high thermal capacity and higher thermal resistance until it (sodium) melts and rapidly reduces the thermal resistance and helps to dissipate heat transfer once it (sodium) converts into vapors. The vapors dissipate the heat from the wick of a bottom portion 14(b) at an end that is opposite to the interface of the piston 10 and heat pipe 14.

[0012] With the above disclosed piston and heat pipe 14, we can have a low-cost effective solution in dissipating heat from the bottom end portion 12 of the piston 10. The heat pipe 14 can be used as a retrofit solution to the existing heat pipes 14, as no additional component or any modification in the design of the piston 10 is needed.

[0013] The embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiments explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims
, Claims:We Claim:
1. A piston (10) positioned within an internal combustion engine, said piston (10) comprising ;
- a top end portion (15) and a bottom end portion (12);
characterized in that :
- at least one heat pipe (14) secured to said bottom end portion (12) of said piston (10), said at least one heat pipe (14) comprises a hollow tube (15).

2. The piston (10) as claimed in claim 1, wherein one end of said at least one heat pipe (14) is secured to a hot portion at said bottom end portion (12) of said piston (10) and the opposite end is positioned away from said bottom end portion (12) of said piston (10) and located opposite to an interface of said heat pipe (14) and said piston (10).

3. The piston (10) as claimed in claim 1, wherein four heat pipes (14) are integrated spreading across a circumference of said bottom end portion (12) of said piston (10).

4. The piston (10) as claimed in claim 1, wherein said at least one heat pipe (14) is closed at both ends before securing an end of said at least one heat pipe (14) to said bottom end portion (12) of said piston (10).

5. The piston (10) as claimed in claim 1, wherein a quantity and type of material filled in said hollow tube (15) is chosen based on at least one parameter, wherein said parameter is chosen from any one of the following comprising a wick volume, porosity, an evaporator volume, and a density variation during a phase change.

6. The piston (10) as claimed in claim 1, wherein a working material of said heat pipe (14) has a low melting point and is chosen from a group of materials comprising sodium, potassium, and cesium.
7. The piston (10) as claimed in claim 1, wherein said working material converts to a vapor state on receiving heat and dissipates the heat through a wick defined at a bottom portion 14(a) of said heat pipe (14) .

8. The piston (10) as claimed in claim 1, wherein dimensions of said heat pipe (14) is made to conform to a cut-section (16) defined in said bottom end portion (12) of said piston (10).

9. The piston (10) as claimed in claim 1, wherein working material has high thermal resistance up to said melting point and heat is dissipated after said melting point is attained.