Method of making a cylinder liner

Details Method of making a cylinder liner Method of making a cylinder liner

1999-10-04

2001-02-06

McMahon, Marquerite (Department: 3747)

Internal-combustion engines

Particular piston and enclosing cylinder construction

Cylinder detail

C029S888061

Reexamination Certificate

active

06182629

ABSTRACT:

CROSS-REFERENCE TO RELATED APPLICATION
This application claims the priority of German Application No. 198 45 347.7 filed Oct. 2, 1998, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
The invention relates to a cylinder liner to be inserted into the cylinder bore of an engine block. The liner is made in a free-form method by thermal spraying of a spray material onto a mandrel serving as a mold body to obtain a cylinder wall.
The engine block of an internal-combustion engine typically comprises a cast-iron or aluminum alloy. Cylinder liners are cast in the engine block which is made by a casting method. Wear-resistant metals or metal alloys serve as the material for the cylinder liner which may be manufactured in numerous ways.
A method of producing aluminum cylinders having cast steel liners is disclosed in German Patent No. 12 82 243. First, a steel tube is made by thermal spraying, then inserted, as a separate body, into the metal block. To connect the liner to the cast material, a vacuum is generated in the liner to cause the melted aluminum to penetrate the pores of the steel tube. Multi-layer cylinder liners have been developed to simplify this complex connecting technique. The layer forming the running surface comprises a wear-resistant and scorch-mark-resistant material. An outer cover layer comprising, for example, an aluminum alloy is sprayed onto the layer forming the running surface.
In the casting process for liners of the above-outlined type the liquid engine-block material fuses with the cover layer. German Patent No. 196 05 946, to which corresponds U.S. Pat. No. 5,929,405, discloses such a cylinder liner and a method of producing the same.
It has been found that in complex geometrical configurations of the engine block the hardening process, in conjunction with the shrinkage of the cast material, leads to stresses in the cooled cast piece. This results in considerable distortions in the region of the liner,
Because the cylinder liners often require machining after casting, the wall thicknesses of the liners may be partially reduced. During engine operation, these regions represent critical zones in terms of thermal and mechanical stability.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an improved liner of the above-outlined type which prevents the occurrence of distortions during casting or engine operation.
This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the cylinder liner for an internal-combustion engine includes a tubular liner wall having circumferentially spaced thickened wall portions.
Cylinder liners according to the invention can be produced with particularly thin walls. The thickened wall portions at the outer circumferential surface of the liner effectively reinforce the stability of the liner so that no distortions occur after casting the material of the cylinder block. The thickened wall portions in the form of ribs can be adapted to the respective application, both in the local arrangement and the number of ribs. A thickened wall portion should preferably be provided at least at three circumferential locations of the liner. The control of the spraying process effects different cross-sectional shapes of the material buildup. Polygonal cross sections can be used in addition to round cross sections. For the rods which form ribs to constitute the thickened wall portions, advantageously cross-sectional shapes are chosen which lend a high bending and/or torsional resistance to the rods.


REFERENCES:
patent: 3165983 (1965-01-01), Thomas
patent: 3276082 (1966-10-01), Thomas
patent: 5829405 (1998-11-01), Godel
patent: 5958520 (1999-09-01), Cooke et al.
patent: 6044820 (2000-04-01), Domanchuk et al.
patent: 1 282 243 (1969-07-01), None
patent: 2 344 899 (1974-02-01), None
patent: 196 05 946 (1997-07-01), None
patent: 1043913 (1953-11-01), None
patent: 2 413 553 (1979-07-01), None

Affiliated with

Also associated with

Rating

Method of making a cylinder liner does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method of making a cylinder liner, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of making a cylinder liner will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2591764