Valve seat

Patent metadata

Field	Value
Publication number	US-10036287-B2
Application number	US-201615219594-A
Country	US
Kind code	B2
Filing date	Jul 26, 2016
Priority date	Sep 5, 2013
Publication date	Jul 31, 2018
Grant date	Jul 31, 2018

Abstract

The valve seat includes an iron-based sintered alloy subjected to oxidation treatment, which is obtained by subjecting an iron-based sintered alloy including: 4 mass % to 15 mass % of Co particles; and hard particles each containing at least one compound of an intermetallic compound, a carbide, a silicide, a nitride, or a boride that has one or more kinds of elements selected from group 4a to 6a elements in a periodic table, and having a hardness of from 600 HV to 1,600 HV to oxidation treatment, and which has an oxide mainly including triiron tetraoxide (Fe 3 O 4 ) and cobalt oxide (CoO) formed on a surface and in an interior of the iron-based sintered alloy. The iron-based sintered alloy subjected to oxidation treatment has an area ratio of the oxide of from 5% to 25% in a cross section thereof in a state prior to installation on the cylinder head.

First claim

The invention claimed is:

1. A manufacturing method for a valve seat to be installed on a cylinder head of an internal combustion engine,
the manufacturing method comprising subjecting an iron-based sintered alloy comprising: 4 mass % to 15 mass % of Co particles each having a Co component purity of 99 mass % or more; and 5 mass % to 45 mass % of hard particles each having a hardness of from 600 HV to 1,600 HV and comprising Co-based alloy particles to oxidation treatment, to thereby manufacture a valve seat comprising an iron-based sintered alloy subjected to oxidation treatment, which has an oxide mainly comprising triiron tetraoxide (Fe 3 O 4 ) and cobalt oxide (CoO) formed on a surface or in an interior of the iron-based sintered alloy, and which has an area ratio of the oxide of from 5% to 25% in a cross section thereof in a state prior to installation on the cylinder head.

2. A manufacturing method for a valve seat according to claim 1 , wherein the Co particles have an average particle size of from 10 μm to 40 μm.

3. A manufacturing method for a valve seat according to claim 1 , wherein the Co-based alloy particles each contain 28 mass % to 38 mass % of Co, and the carbide.

4. A manufacturing method for a valve seat according to claim 1 , wherein the iron-based sintered alloy has an area ratio of the hard particles of from 5% to 45% in a cross section thereof.

5. A manufacturing method for a valve seat according to claim 1 , wherein the iron-based sintered alloy further comprises a solid lubricant.

6. A manufacturing method for a valve seat according to claim 5 , wherein the solid lubricant has an average particle size of from 1 μm to 10 μm.

Assignees

• Tpr Co Ltd

Inventors

• Koyama Yoshio
• HARA Shohtaroh

Classifications

• F01L2303/00

  Manufacturing of components used in valve arrangements · CPC title

• F01L2301/02

  Using ceramic materials · CPC title

• F01L2301/00

  Using particular materials · CPC title

• F16K25/005

  Particular materials for seats or closure elements · CPC title

• B22F1/10

  Metallic powder containing lubricating or binding agents; Metallic powder containing organic material · CPC title