Valve operating device for internal combustion engine

Patent metadata

Field	Value
Publication number	US-10125643-B2
Application number	US-201615333395-A
Country	US
Kind code	B2
Filing date	Oct 25, 2016
Priority date	Dec 24, 2015
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

In an engine valve, a first sliding area formed at a valve head side in an outer face of a valve stem, and sliding along a stem guide, a second sliding area formed at an opposite side from the valve head side, and sliding along the stem guide, and a first small diameter area formed between the first sliding area and the second sliding area are formed. Further, in the engine valve, a length, in an axial direction of the valve stem, of the first sliding area abutting on the stem guide at a position where the engine valve is fully opened is longer as compared with a length, in the axial direction of the valve stem, of the second sliding area abutting on the stem guide at a position where the engine valve is fully closed.

First claim

What is claimed is:

1. A valve operating device for an internal combustion engine, comprising:
an engine valve comprising a valve stem portion and a valve head portion connected to one end of the valve stem portion, the valve stem portion including a cylindrical sliding area sliding along a stem guide and a first small diameter area having a smaller diameter as compared with a diameter of the sliding area; and
a valve drive device configured to drive the engine valve between a fully opened position where a lift amount of the valve head portion becomes maximum to an opening side, and a fully closed position where the lift amount becomes minimum, wherein
the sliding area includes a first sliding area between the valve head portion and the first small diameter area, and a second sliding area between the first small diameter area and the other end of the valve stem portion; and
an amount of lubricating oil Q passing through clearance between the stem guide and the valve stem portion is represented by Formula 1, wherein Δp represents differential pressure, μ represents viscosity coefficient of the lubricating oil, and l represents either a length la of radial clearance in the first sliding area or a length lb of radial clearance in the second sliding area, wherein

Q
=

π
⁢

⁢

dy
3

12
⁢

⁢
μ
⁢

⁢
l

⁢
Δ
⁢

⁢
p

(

Formula
⁢

⁢
1

)

the length la in an axial direction of the first sliding area abutting on the stem guide at the fully opened position is longer as compared with the length lb in an axial direction of the second sliding area abutting on the stem guide at the fully closed position, so that lubricating oil retentivity in the first sliding area is larger than lubricating oil retentivity in the second sliding area.

2. The valve operating device for an internal combustion engine according to claim 1 , wherein the valve stem portion further includes a second small diameter area having a smaller diameter as compared with a diameter of the first sliding area between the valve head portion and the first sliding area, and the second small diameter area resides at a position not abutting on the stem guide at the fully closed position.

Assignees

• Toyota Motor Co Ltd

Inventors

• Katsumata Shouji
• Hirose Hidetoshi

Classifications

• F01L3/20 Primary

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

• F01L5/24 Primary

  Component parts, details or accessories, not provided for in preceding subgroups in this group · CPC title

• F01L2810/02

  Lubrication · CPC title

• F01L5/02

  with other than cylindrical, sleeve or part annularly shaped valves, e.g. with flat-type valves · CPC title

• F01L3/08 Primary

  Valves guides; Sealing of valve stem, e.g. sealing by lubricant · CPC title