US2012073534A1PendingUtilityA1

Valve lifter for internal combustion engine

37
Assignee: TANAKA TOMOYAPriority: Sep 28, 2010Filed: Mar 31, 2011Published: Mar 29, 2012
Est. expirySep 28, 2030(~4.2 yrs left)· nominal 20-yr term from priority
Inventors:Tomoya TanakaNoriomi HosakaSeiji Tsuruta
F01L 2820/045F01L 3/085F01L 1/143
37
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Claims

Abstract

A valve lifter for an internal combustion engine includes a skirt portion formed in a tubular shape; and a crown portion formed integrally with an axially one end side of the skirt portion. The crown portion includes a crown surface configured to slide in contact with an outer circumferential surface of a cam. An axis of the crown portion is eccentric from a center of the cam in a width direction of the cam. The crown surface is formed in a spherical protruding shape to have its uppermost portion at a center of the crown surface. A protruding amount of the spherical protruding shape is set to range from 11 μm to 50 μm.

Claims

exact text as granted — not AI-modified
1 . A valve lifter for an internal combustion engine, comprising:
 a skirt portion formed in a tubular shape; and   a crown portion formed integrally with an axially one end side of the skirt portion, the crown portion including a crown surface configured to slide in contact with an outer circumferential surface of a cam,   wherein an axis of the crown portion is eccentric from a center of the cam in a width direction of the cam,   wherein the crown surface is formed in a spherical protruding shape to have its uppermost portion at a center of the crown surface,   wherein a protruding amount of the spherical protruding shape is set to range from 11 μm to 50 μm.   
     
     
         2 . The valve lifter as claimed in  claim 1 , wherein
 a diamond-like carbon treatment is applied to at least the crown surface.   
     
     
         3 . The valve lifter as claimed in  claim 1 , wherein
 the crown portion is formed with at least one oil hole passing through the crown portion, and   the at least one oil hole is formed at a location other than a region at which the crown surface of the crown portion slides in contact with the cam.   
     
     
         4 . The valve lifter as claimed in  claim 1 , wherein
 an eccentricity amount of the axis of the crown portion relative to the center of the cam in the width direction of the cam is set to range from 0.9 mm to 1.1 mm.   
     
     
         5 . The valve lifter as claimed in  claim 1 , wherein
 a width of the cam is set to range from 6 mm to 12 mm.   
     
     
         6 . The valve lifter as claimed in  claim 1 , wherein
 whole of the valve lifter is formed of an iron-based metal.   
     
     
         7 . A valve lifter for an internal combustion engine, comprising:
 a skirt portion formed in a tubular shape; and   a crown portion formed integrally with an axially one end side of the skirt portion, the crown portion including a crown surface configured to slide in contact with an outer circumferential surface of a cam,   wherein an axis of the crown portion is located to be offset from a center of the cam in a width direction of the cam,   wherein the crown surface is formed in a spherical protruding shape to have its uppermost portion at a center of the crown surface,   wherein a protruding amount of the spherical protruding shape is larger than 11 μm and smaller than a boundary value below which the valve lifter rotates by a rotational force of the cam.   
     
     
         8 . The valve lifter as claimed in  claim 7 , wherein
 a diamond-like carbon treatment is applied to at least the crown surface.   
     
     
         9 . The valve lifter as claimed in  claim 7 , wherein
 the crown portion is formed with at least one oil hole passing through the crown portion, and   the at least one oil hole is formed at a location other than a region at which the crown surface of the crown portion slides in contact with the cam.   
     
     
         10 . The valve lifter as claimed in  claim 7 , wherein
 an offset amount of the axis of the crown portion relative to the center of the cam in the width direction of the cam falls within a range from 0.9 mm to 1.1 mm.   
     
     
         11 . The valve lifter as claimed in  claim 7 , wherein
 a width of the cam falls within a range from 6 mm to 12 mm.   
     
     
         12 . The valve lifter as claimed in  claim 7 , wherein
 whole of the valve lifter is formed of an iron-based metal.   
     
     
         13 . A valve lifter for an internal combustion engine, comprising:
 a skirt portion formed in a tubular shape; and   a crown portion formed integrally with an axially one end side of the skirt portion, the crown portion including a crown surface configured to slide in contact with an outer circumferential surface of a cam,   wherein a center of the crown portion is located to be offset from a center of the cam in a width direction of the cam,   wherein the crown surface is formed in a spherical protruding shape to have its uppermost portion at a center of the crown surface,   wherein a protruding amount of the spherical protruding shape is set to be larger than 11 μm,   wherein the protruding amount of the spherical protruding shape is set to be smaller than a boundary value below which a contact portion between the outer circumferential surface of the cam and the crown surface forms an asymmetrical shape with respect to a center line of the crown surface perpendicular to the width direction of the cam.   
     
     
         14 . The valve lifter as claimed in  claim 13 , wherein
 a diamond-like carbon treatment is applied to at least the crown surface.   
     
     
         15 . The valve lifter as claimed in  claim 13 , wherein
 the crown portion is formed with at least one oil hole passing through the crown portion, and   the at least one oil hole is formed at a location other than a region at which the crown surface of the crown portion slides in contact with the cam.   
     
     
         16 . The valve lifter as claimed in  claim 13 , wherein
 an offset amount of the center of the crown portion relative to the center of the cam in the width direction of the cam falls within a range from 0.9 mm to 1.1 mm.   
     
     
         17 . The valve lifter as claimed in  claim 13 , wherein
 a width of the cam falls within a range from 6 mm to 12 mm.   
     
     
         18 . The valve lifter as claimed in  claim 13 , wherein
 whole of the valve lifter is formed of an iron-based metal.

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