Low heat transfer piston via binder jet technology

Patent metadata

Field	Value
Publication number	US-11112009-B2
Application number	US-202016839626-A
Country	US
Kind code	B2
Filing date	Apr 3, 2020
Priority date	Apr 10, 2019
Publication date	Sep 7, 2021
Grant date	Sep 7, 2021

Abstract

A piston for an internal combustion engine includes a skirt and a crown coupled to the skirt. The crown is produced in isolation from the skirt using an additive manufacturing process. The piston includes a first air gap between the crown and the skirt. According to an example embodiment, the crown includes a plurality of sections produced in isolation from the skirt. The crown may include a second air gap disposed between two of the plurality of sections.

First claim

What is claimed is:

1. A piston, comprising:
a skirt; and
a crown sintered to the skirt, the crown produced in isolation from the skirt using an additive manufacturing process, the piston including a first air gap between the crown and the skirt.

2. The piston of claim 1 , wherein at least one of the crown and the skirt comprises a recessed area, the recessed area disposed between the skirt and the crown so as to form the first air gap.

3. The piston of claim 1 , wherein the crown comprises a plurality of sections produced in isolation from the skirt using the additive manufacturing process, the crown including a second air gap disposed between two of the plurality of sections such that the piston includes a plurality of air gaps.

4. The piston of claim 3 , wherein each one of the plurality of air gaps comprises a plurality of air pockets distributed in a row between either (i) two sections of the plurality of sections; or (ii) the crown and the skirt, and wherein a total number of air gaps is equal to a total number of sections.

5. The piston of claim 1 , wherein the skirt comprises an upper portion and a lower portion extending downwardly from the upper portion, the lower portion defining a cylindrical tube, wherein the upper portion includes an upper wall that extends across a first end of the cylindrical tube and covers the first end, and wherein the crown is coupled to the upper wall.

6. The piston of claim 1 , wherein at least one of the crown or the skirt comprises an isogrid, the isogrid comprising a plurality of ribs defining a plurality of recessed areas, the plurality of recessed areas forming a portion of the first air gap.

7. The piston of claim 6 , wherein the crown comprises a plurality of sections including a middle section, wherein the middle section includes a middle upper isogrid disposed on an upper surface of the middle section and a middle lower isogrid disposed on a lower surface of the middle section, and wherein an outer diameter of the middle upper isogrid is greater than an outer diameter of the middle lower isogrid.

8. The piston of claim 1 , wherein at least one of the crown or the skirt includes an oil port that fluidly couples the first air gap to a lower portion of the skirt.

9. An internal combustion engine, comprising:
a cylinder block defining a cavity;
a cylinder head coupled to an upper end of the cylinder block and covering the cavity;
a piston at least partially disposed within the cavity, the piston comprising:
a skirt; and
a crown sintered to the skirt, the crown produced in isolation from the skirt using an additive manufacturing process, the piston including a first air gap between the crown and the skirt.

10. The internal combustion engine of claim 9 , wherein at least one of the skirt or the crown comprises a recessed area, and wherein the recessed area is disposed between the skirt and the crown so as to form the first air gap.

11. The internal combustion engine of claim 9 , wherein the crown comprises a plurality of sections produced in isolation from the skirt using the additive manufacturing process, the crown including a second air gap disposed between two of the plurality of sections such that the piston includes a plurality of air gaps.

12. The internal combustion engine of claim 9 , wherein the skirt comprises an upper portion and a lower portion extending downwardly from the upper portion, wherein the lower portion defines a cylindrical tube, wherein the upper portion includes an upper wall that extends across a first end of the cylindrical tube and covers the first end, and wherein the crown is coupled to the upper wall.

13. The internal combustion engine of claim 9 , wherein at least one of the crown or the skirt comprises an isogrid, wherein the isogrid comprises a plurality of ribs defining a plurality of recessed areas, and wherein the plurality of recessed areas form a portion of the first air gap.

14. The internal combustion engine of claim 9 , further comprising a crankcase coupled to the cylinder block, wherein the piston includes an oil port that fluidly couples the first air gap to the crankcase.

15. A method, comprising:
forming a skirt using an additive manufacturing process;
forming a crown in isolation from the skirt using the additive manufacturing process, at least one of the skirt or the crown comprising a recessed area;
positioning crown onto the skirt such that the recessed area is disposed therebetween; and
sintering the crown to the skirt.

16. The method of claim 15 , wherein the recessed area is one of a plurality of recessed areas, and wherein at least one of the skirt or the crown comprises a plurality of ribs defining the plurality of recessed areas.

17. The method of claim 15 , wherein forming the crown comprises forming a first section using the additive manufacturing process, and forming a second section in isolation from the first section using the additive manufacturing process.

18. The method of claim 17 , further comprising:
positioning the first section onto the skirt;
positioning the second section onto the first section; and
joining both the first section and the second section to the skirt.

Assignees

• Cummins Inc

Inventors

• Barnes David M

Classifications

• B33Y10/00 Primary

  Processes of additive manufacturing · CPC title

• B22F10/25

  Direct deposition of metal particles, e.g. direct metal deposition [DMD] or laser engineered net shaping [LENS] · CPC title

• B22F10/14

  by jetting of binder onto a bed of metal powder · CPC title

• B22F10/28

  Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM] · CPC title

• B22F2998/10

  Processes characterised by the sequence of their steps · CPC title