| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for measuring a film thickness and a contact state which can accurately measure the film thickness of an oil film of a lubricant by capacitance measurement in a fluid lubricated state and can evaluate the contact state of a piston ring in relation to a cylinder liner by electric resistance measurement in a boundary lubrication state. <P>SOLUTION: In an arithmetic evaluation unit 13 for the film thickness and contact state, a switch 9 is ordinarily switched over to a capacitance measuring circuit 10 side by a switchover command signal 13a at every prescribed crank rotation angle at which a measuring trigger signal 14a from a crank rotation angle detector 14 is inputted, and the film thickness of the oil film in the fluid lubricated state is determined on the basis of a measured value obtained by the capacitance measuring circuit 10. Meanwhile, when the film thickness becomes a set value or below while the piston ring 5 passes a place where a sensor electrode 8 is buried, the switch 9 is switched over to the electric resistance measuring circuit 11 side by the switchover command signal 13a and the contact state of the piston ring 5 in relation to the cylinder liner 3 in the boundary lubrication state is evaluated on the basis of the measured value by an electric resistance measuring circuit 11. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
