Patent ID: 9212574
Filing Date: 2015-12-15
Classification: F01L,F02M,Y02T

Abstract:
1. A valve operating system of an internal combustion engine, the valve operating system comprising: a decompression cam member that is supported on a camshaft provided with a valve operating cam and that moves between an operating position in which an exhaust valve operating member is operated in an opening direction of an exhaust valve in a compression stroke of the engine and a non-operational position in which the exhaust valve operating member is released, an exhaust gas recirculation cam member that is supported on the camshaft and that moves between a non-operational position in which the exhaust valve operating member is released and an operating position in which the exhaust valve operating member can be operated in the opening direction of the exhaust valve in an intake stroke of the engine, and a centrifugal mechanism that is mounted on a driven timing rotating member driven by the crankshaft so as to rotate integrally with the valve operating cam, that makes the decompression cam member move to the operating position in a starting rotational region of the engine and to the non-operational position after starting, and that makes the exhaust gas recirculation cam member move to the nonoperational position in a low-speed running region of the engine and to the operating position in a high-speed running region, wherein the driven timing rotating member is integrally formed on one axial end portion of the valve operating cam, wherein the valve operating cam is provided with a recess surrounding the camshaft, the recess opening on a face on the other side of the driven timing rotating member that is opposite the valve operating cam and on a base circle face of the valve operating cam, the recess being closed at one axial end portion thereof by the valve operating cam, wherein the decompression cam member and the exhaust gas recirculation cam member are housed in the recess, wherein the centrifugal mechanism comprises a centrifugal weight which is swingably supported on the driven timing rotating member so as to close a part of an open face of the recess at its other axial end portion, and wherein the valve operating cam is fitted onto and secured to the camshaft, which is a separate body from the valve operating cam, such that formation of the recess on the valve operating cam can be done without interference from the camshaft.