# US 4,393,821 A · Cylinder or cylinder liner

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- Number: US 4,393,821 A
- Document ID: US4393821A
- Status: Granted
- Kind: A
- Application number: 06/151,064
- Filed: 1980-05-19
- Granted: 1983-07-19
- Earliest claimed: 1979-05-22
- Assignees: Nippon Piston Ring Co., Ltd.
- Inventors: Shigeru Urano
- Web page: https://patentgrep.com/patent/US4393821A

## CPC

- C21D 9/14: wear-resistant or pressure-resistant pipes
- F16J 9/00: Piston-rings {, e.g. non-metallic piston-rings}, seats therefor; Ring sealings of similar construction (other sealings between pistons and cylinders F16J3/06, F16J15/16 {; manufacture of piston-rings B23P15/06, B23P15/08}; tools for mounting or removing piston-rings or the like B25B; piston sealing arrangements on brake master cylinders B60T11/236 {; sealing provided on pump pistons F04B53/143})
- F16J 10/04: Running faces; Liners
- Y10T 29/4927: Cylinder, cylinder head or engine valve sleeve making
- Y10T 29/49272: with liner, coating, or sleeve
- C21D: MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING (surface treatment of metallic material involving at least one process provided for in class C23 and at least one process covered by this subclass C23F17/00; unidirectional solidification of eutectic materials or unidirectional demixing of eutectoid materials C30B)
- F16J: PISTONS {(specially adapted for dampers F16F9/32)}; CYLINDERS; SEALINGS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

An internal combustion engine including a piston and cylinder liner in which the cylinder liner is provided with plural annular hardened layers formed on the inner peripheral surface thereof in the vicinity of the top dead center of the piston. The distance between adjacent ones of the annular hardened layers is smaller than the axial length of a piston ring employed with the piston. The width of each of the hardened layers is in a range of from one-half to twice the axial length of the piston ring. The hardened layers may be formed by hardening with a laser beam. The piston ring can be provided with a hardened layer on its outer surface. The piston ring preferably has a barrel shape.

## Claims

### Claim 1

An internal combustion engine comprising: a piston, a cylinder and a cylinder liner, said piston being operatively disposed in said cylinder, said cylinder liner having a plurality of spaced separate annular hardened layers produced directly from the cylinder liner without discontinuity, on the inner peripheral surface of said liner in the vicinity of the top dead center of said piston, the distance between adjacent annular hardened layers being smaller than an axial length of a piston ring of said piston.

### Claim 2 (depends on 1)

The internal combustion engine as claimed in claim 1 wherein said hardened layers comprise annular inner wall surface portions of said liner hardened with a laser beam and, the width of each of said hardened layers is in a range of from a half of said axial length of said piston ring to twice said axial length.

### Claim 3 (depends on 1)

The internal combustion engine as claimed in claim 1 wherein said piston ring has an outer peripheral surface having a barrel shape and having an outer hard layer covering at least a portion of said outer peripheral surface.

### Claim 4 (depends on 1, 2)

The internal combustion engine as claimed in any of claims 1, 2, or 3 wherein the distances between ones of said hardened layers gradually increase in axial length towards the top dead center of said piston.

### Claim 5 (depends on 1, 2)

The internal combustion engine as claimed in any of claims 1, 2, or 3 wherein the distances between ones of said hardened layers gradually decrease in axial length towards the top dead center of said piston.

### Claim 6 (depends on 1, 2)

The internal combustion engine as claimed in any of claims 1, 2, or 3 wherein said distance between adjacent annular hardened layers is in a range of from 30% to 90% of the axial length of said piston ring.