|
Analysis of the oil
film behavior between piston and a cylinder liner
is of great importance for reducing the friction
loss and oil consumption in reciprocating engines.
Laser-induced-fluorescence (LIF) technique has recently
attracted much attention as a new method for the
analysis.
In this study, an
advanced LIF method has been developed in which
an observed point is scanned using fiber optics
and a rotating polygonal mirror. This 'Scanning-LIF'
system has made it possible to observe changes in
the piston axial oil film distribution during the
operation. The accuracy of the system in measuring
oil film thickness has been improved by using the
optimal fluorescent dye.
Characteristics of
the oil film behavior were clarified in relation
to operating conditions and piston ring specifications
as follows;
(1) Starvation frequently
occurs in the top-ring oil film during the firing
operation.
(2) Oil volume on
the piston third land increases with the decrease
in the tangential force of the oil ring and flattening
of its profile.
(3) Oil film rupture
often occurs in the piston skirt area just before
the top dead center due to the piston slap motion.
@
|
