Gas exchange valve

Patent metadata

Field	Value
Publication number	US-2016169400-A1
Application number	US-201514966522-A
Country	US
Kind code	A1
Filing date	Dec 11, 2015
Priority date	Dec 12, 2014
Publication date	Jun 16, 2016
Grant date	—

Abstract

A gas exchange valve of an internal combustion engine may include a valve plate and a valve stem. A nickel-phosphorus layer may be disposed on at least the valve stem. The nickel-phosphorus layer may have a phosphorus content that is greater than 10 percent by volume. A method and apparatus for coating a gas exhaust valve are also disclosed.

First claim

1 . A gas exchange valve of an internal combustion engine, comprising:
a valve plate and a valve stem, and a nickel-phosphorus layer disposed on at least the valve stem, wherein the nickel-phosphorus layer has a phosphorus content greater than 10% by volume.

2 . The gas exchange valve according to claim 1 , wherein the nickel-phosphorus layer has a layer thickness of 8 μm to 15 μm.

3 . The gas exchange valve according to claim 1 , further comprising a nickel strike layer arranged between the valve stem and the nickel-phosphorus layer.

4 . The gas exchange valve according to claim 1 , further comprising a chromium layer disposed on at least part of the nickel-phosphorus layer.

5 . The gas exchange valve according to claim 4 , wherein the chromium layer and the nickel-phosphorus layer together define a total thickness of 25 μm or less.

6 . The gas exchange valve according to claim 1 , wherein the nickel-phosphorus layer is disposed only in a region of a valve guide on the valve stem.

7 . The gas exchange valve according to claim 1 , wherein at least one of the valve plate and the valve stem is composed of at least one of a X50CrMnNiNbN21-9 (1.4882) steel, a NiCr20TiAl (Nimonic 80A 2.4952) steel and a Nireva 3015 steel.

8 . A method for coating a gas exchange valve comprising:
providing a valve stem and a valve plate; dispersing a nickel strike layer galvanically at least in a region of a valve guide of the valve stem, and applying a nickel-phosphorus layer galvanically at least in the region of the valve guide, wherein the nickel-phosphorus layer has a phosphorus content greater than 10% by volume.

9 . The method according to claim 8 , further comprising covering the nickel-phosphorus layer at least partly with a chromium layer.

10 . An apparatus for coating a gas exchange valve comprising:
a galvanic bath and an anode disposed in the galvanic bath, wherein the anode includes a mounting configured to receive a valve stem end of a valve stem, and wherein the anode has a negative contour of a valve throat, and a cathode configured to be placed flush against a base of a valve plate, wherein the cathode is configured to communicate an electrical current to at least one of the valve stem and the valve plate.

11 . The apparatus according to claim 10 , further comprising a mixing device disposed in the galvanic bath for mixing a galvanic fluid.

12 . The gas exchange valve according to claim 1 , wherein the phosphorus content ranges from 11% by volume to 13% by volume.

13 . The gas exchange valve according to claim 12 , wherein the nickel-phosphorus layer has a layer thickness of 8 μm to 15 μm.

14 . The gas exchange valve according to claim 12 , further comprising a chromium layer disposed on at least part of the nickel-phosphorus layer.

15 . The gas exchange valve according to claim 14 , wherein the chromium layer and the nickel-phosphorus layer together define a total thickness of 25 μm or less.

16 . The gas exchange valve according to claim 12 , further comprising a nickel strike layer disposed between the valve stem and the nickel-phosphorus layer.

17 . The gas exchange valve according to claim 3 , wherein the nickel strike layer has a thickness of 2 μm or less.

18 . The gas exchange valve according to claim 17 , wherein the phosphorus content ranges from 11% by volume to 13% by volume.

19 . The gas exchange valve according to claim 3 , wherein at least the valve stem is composed of at least one of a X50CrMnNiNbN21-9 (1.4882) steel, a NiCr20TiAl (Nimonic 80A 2.4952) steel and a Nireva 3015 steel.

20 . The gas exchange valve according to claim 3 , further comprising a chromium layer disposed on at least part of the nickel-phosphorus layer.

Assignees

• Mahle Int Gmbh

Inventors

• Dogar Andreas
• Koerner Stephan
• Rose Reinhard

Classifications

• F01L3/20 Primary

  Shapes or constructions of valve members, not provided for in preceding subgroups of this group · CPC title

• F01L3/04

  Coated valve members or valve-seats · CPC title

• F16K25/04 Primary

  Arrangements for preventing erosion, not otherwise provided for · CPC title

• C25D7/00

  Electroplating characterised by the article coated · CPC title

• C25D5/617

  Crystalline layers · CPC title