Patent ID: 9151209
Filing Date: 2015-10-06
Classification: F01L,F01M,F01P

Abstract:
1. An oiling structure for an engine, including a cylinder head of the engine having a combination of intake and exhaust cam shafts, rocker arms adapted to swing in conjunction with rotations of said cam shafts, valves adapted to carry out opening and closing operations in conjunction with swing motions of the rocker arms, and housing pairs, with each cam housing pair including a lower cam housing and an upper cam housing arranged to rotatably support the cam shafts, wherein the rocker arms are each swingably supported at one-end thereof via hydraulic lash adjusters, and oil from an oil pump is guided to the lash adjusters through an oil passage system including oil passages for the lash adjusters formed in the cylinder head, wherein the lower cam housings include a lower cam housing formed as a separate body from the cylinder head and joined to the cylinder head, with a joint surface region between the cylinder head and the lower cam housing, and the oil passage system comprises: a set of first upper oil passages formed inside the cylinder head, extending from the oil passages for the lash adjusters to the joint surface region, the first upper oil passages having upstream ends thereof opened at the joint surface region; an oil entry passage formed in the cylinder head, for entry thereto of oil from the oil pump, the oil entry passage having a downstream end opened at the joint surface region; and a second upper oil passage formed in the lower cam housing to conduct oil to the joint surface region from above the joint surface region, the second upper oil passage having an upstream end thereof communicating with the oil entry passage at the joint surface region, and downstream ends of the second upper oil passage communicating with the set of first upper oil passages at the joint surface region, wherein the lash adjusters include an intake lash adjuster and an exhaust lash adjuster, the oil passages for the lash adjusters include an intake side oil passage communicating with a first oil hole at the intake lash adjuster, and an exhaust side oil passage communicating with a second oil hole at the exhaust lash adjuster, the set of first upper oil passages includes an intake side first upper oil passage communicating with the intake side oil passage, and an exhaust side first upper oil passage communicating with the exhaust side oil passage, and the downstream ends of the second upper oil passage include a first downstream end communicating with the intake side first upper oil passage, and a second downstream end communicating with the exhaust side first upper oil passage, and the oiling structure further comprising a first upwardly extending oil passage extending from the intake side oil passage to a first cam support surface of the lower cam housing supporting an intake cam shaft, and a second upwardly extending oil passage extending from the exhaust side oil passage to a second cam support surface of the lower cam housing supporting an exhaust cam shaft.