Flexibly making engine block assemblies
Reference Number: N 01-02
Inventors: Rao, V. Durga Nageswar; Rose, Robert A.; Yeager, David A.; Kabat, Daniel M.
Owner: NISTAC
USPTO Link:5566450
Invention Summary
The invention is a method of flexibly manufacturing engine blocks by first bonding
extruded tube liners, of a given thickness, to the bore walls of a fixed configuration
block, the liner having been coated with a wear-resistant anti-friction coating having
a controlled standard thickness, and secondly bonding extruded tube liners of a different
wall thickness to the bore walls of another of the fixed configuration blocks, the
second liners again having been coated with the same type of wear-resistant anti-friction
coating in the same controlled standard thickness.
More particularly the method comprises: (a) making at least first and second engine
blocks with commonly sized cylinder bore walls; (b) preparing a set of first liner
inserts for the first block from extruded tubing and a set of second liner inserts
for the second liner inserts for the second block from other extruding tubing, each
set of liner inserts having a different wall thickness resulting from selecting extruded
tubing of a different wall thickness in the range of 1-15 mm; (c) implanting the set
of first liner inserts into the first block and the set of second liner inserts into
the second block, said implanting being with a fit that promotes thermal conductivity
across the face between said inserts and bore wall; and (d) applying an adherent anti-friction
wear-resistant coating to at least a zone of the interior of each liner insert, said
coating being controlled as to uniform thickness, concentricity, and trueness to the
operating axes of said engine blocks, said coating being applied either prior to or
subsequent to said implanting.
The common sized engine blocks may have identically shaped circular cylindrical bore
walls with the variable selection of the wall thickness of said extruded tubing correlating
to a cylinder volume displacement change of as much as 100%; or the making of the
engine blocks may be with ovoid cross-sectional cylindrical shapes, the selection
of the ratio of the major to minor axis of such ovoid cross-sectional shape being
in the range of 1.0 to 1.35, the engine blocks having a crankshaft axis with the minor
axis of the ovoid shape being parallel to the plane of such crankshaft axis, the extruded
tubing having an outer surface complementary to the ovoid shape and having an interior
surface the selection of which varies between the circular shape to the ovoid shape,
the design variation in the extruded tubing wall correlating to a cylinder volume
displacement change of as much as 150%.
To promote ease of fabrication and consistent thermal expansion and thermal conductivity
characteristics, the block and liner inserts are both made of aluminum. To promote
wear-resistance and lubricant qualities, the coating contains a mixture of hard particles
(such as steel, stainless steel, nickel, chromium or vanadium) and solid lubricant
particles such as oxides of iron having controlled oxygen, BN, LiF, NaF.sub.2 or a
eutectic of LiF/NaF.sub.2.