Patent ID: 6026772
Filing Date: 2000-02-22
Classification: F01L

Abstract:
A valve characteristics control apparatus for controlling the operational characteristics of the valves of an internal combustion engine opened and closed by a camshaft, comprising:a first oil chamber for generating a force for displacing the camshaft in a first direction when supplied with the working oil;a second oil chamber for generating a force for displacing the camshaft in a second direction opposite to the first direction when supplied with the working oil;a working oil supply control valve arranged in a support member for supporting the camshaft for controlling the working oil supplied to the first oil chamber and the second oil chamber, the working oil being discharged from the second oil chamber when supplied to the first oil chamber, the working oil being discharged from the first oil chamber when supplied to the second oil chamber;a first oil path for leading the working oil from the working oil supply control valve to the first oil chamber and a second oil path for leading the working oil from the working oil supply control valve to the second oil chamber wherein the firet oil path and the second oil path include an annular first oil path and an annular second oil path formed in the camshaft and a sliding portion of the support member for supporting the camshaft, a first in-camshaft oil path formed in the camshaft for connecting the first oil chamber, a second in-camshaft oil path formed in the camshaft for connecting the annular second oil path and the second oil chamber, a first in-support member oil path formed in the support member for connecting the annular first oil path and the working oil supply control valve, and a second in-support member oil path formed in the support member for connecting the annular second oil path and the working oil supply control valve; anda metal bearing arranged between the annular oil paths and cam-side openings of the in-support member oil paths, and at least one of the in-support oil paths reaches a back of the metal bearing from the working oil supply control valve, extends in an axial direction along the back of the metal bearing, comes to communicate with a corresponding annular oil path at a different axial position from the reached point of the back.