Piston with anti-carbon coating and method for applying an anti-carbon coating on a piston

Patent metadata

Field	Value
Publication number	US-9903310-B2
Application number	US-201615147398-A
Country	US
Kind code	B2
Filing date	May 5, 2016
Priority date	May 5, 2016
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

A piston having a piston crown with a combustion chamber, and a circumferential ring belt extending from the piston crown and having a plurality of ring grooves separated by piston lands. At least one of the piston lands, ring grooves or top surface of the crown is provided with a coating comprising hexagonal boron nitride. The coating can be made solely of hexagonal boron nitride, or can additionally include a resin. The coating can be a single layer coating or a multiple layer coating.

First claim

What is claimed is:

1. A piston for an internal combustion engine comprising:
a piston crown having a combustion chamber, and
a circumferential ring belt extending from the piston crown and having a plurality of ring grooves separated by piston lands,
wherein at least one exterior surface of the piston is provided with a multi-layer coating comprising the following components:
a first layer of manganese phosphate;
a second layer consisting of a mixture of hexagonal boron nitride with resin; and
a top layer of pure hexagonal boron nitride.

2. The piston according to claim 1 , wherein the at least one surface comprises one of the piston lands, one of the ring grooves, a top surface of the piston crown or an underside of the piston.

3. The piston according to claim 2 , wherein the at least one surface comprises an uppermost piston land.

4. The piston according to claim 2 , wherein only the top surface of the piston crown is coated with the coating.

5. The piston according to claim 2 , wherein only an uppermost land of the piston is coated with the coating.

6. The piston according to claim 1 , wherein the resin is selected from the group consisting of tetraethyl orthosilicate (TEOS), polyamide-imide (PAI) and polyimide (PI).

7. A method of providing an anti-carbon coating on a piston having a crown and a circumferential ring carrier with a plurality of ring grooves and piston lands, the method comprising:
applying a layer of MnP to the at least one exterior surface of the piston;
mixing h-BN with a resin to create a bondcoat;
applying the bondcoat to the at least one exterior surface of the piston; and
applying a layer of pure h-BN to the at least one exterior surface of the piston.

8. The method according to claim 7 , wherein the at least one surface is selected from the group consisting of the piston lands, ring grooves and a top surface of the crown.

9. The method according to claim 7 , wherein the coating is applied via spraying, dipping or screen printing.

10. The method according to claim 7 , wherein the piston is heated prior to application of each coating at 500 C for 30 min, and the final heating takes place at 3000 C for 1 hour.

11. The method according to claim 7 , wherein the coating is applied only to an uppermost land of the piston.

12. The method according to claim 7 , wherein the coating is applied only to a top surface of the crown.

Assignees

• Mahle Int Gmbh

Inventors

• Bieneman Jason
• NACHAPPA Nikhil

Classifications

• B05D1/18

  performed by dipping · CPC title

• F02F3/26

  having combustion chamber in piston head (the surface thereof being covered F02F3/14) · CPC title

• C09D5/1618

  inorganic · CPC title

• C09D5/1662

  Synthetic film-forming substance · CPC title

• C01B21/064 Primary

  with boron · CPC title