Variable valve lift mechanism for engine and arrangement of oil control valve

Abstract

An engine has a cylinder block mounted on a crankcase and a cylinder head mounted on the cylinder block. The cylinder head has one side forming an intake port and an intake valve and another side forming an exhaust port and an exhaust valve. A camshaft includes an intake cam assembly and an the exhaust cam assembly, which respectively drive an intake valve driving member and an exhaust valve driving member. The intake cam assembly includes a first intake cam and a second intake cam. The intake valve driving member includes a low lift driving member corresponding to the first intake cam and a high lift driving member corresponding to the second intake cam. The low lift driving member and the high lift driving member form a hydraulic cylinder, which receives therein hydraulically operable pistons.

1 . A variable valve lift mechanism for engine and arrangement of oil control valve, the engine comprising a cylinder block mounted on a crankcase and a cylinder head mounted on the cylinder block, the cylinder head forming, in one side, an intake port and an intake valve and an exhaust port and an exhaust valve on another side, a throttle valve communicating through an intake tube with the intake port, the intake valve and the exhaust valve being provided therebetween with a camshaft base, the camshaft base rotatably supporting a camshaft, the camshaft carrying therein an intake cam assembly and an exhaust cam assembly, the intake cam assembly and the exhaust cam assembly respectively driving an intake valve driving member and an exhaust valve driving member, wherein the intake cam assembly comprises a first intake cam and a second intake cam, the intake valve driving member comprising a low lift driving member corresponding to the first intake cam and a high lift driving member corresponding to the second intake cam, the low lift driving member and the high lift driving member forming therein a hydraulic cylinder, the hydraulic cylinder receiving therein hydraulically operable pistons, the oil control valve comprising a driving oil passage communicating the hydraulic cylinder, characterized in that the high lift driving member of the intake valve driving member is more close to the oil control valve than the low lift driving member and the driving oil passage of the oil control valve and the high lift driving member is shorter than the driving oil passage that the oil control valve drives the low lift driving member. 
     
     
         2 . The variable valve lift mechanism for engine and arrangement of oil control valve according to  claim 1 , wherein the surface of the cylinder head on the intake side is provided with an oil control valve seat, which is located on an outer wall of a timing chain chamber, the oil control valve seat being lower than a greatest height of the throttle valve, the oil control valve being mounted to the oil control valve seat. 
     
     
         3 . The variable valve lift mechanism for engine and arrangement of oil control valve according to  claim 2 , wherein the oil control valve seat forms an opening, which faces the cylinder block, whereby the oil control valve is mounted to the oil control valve seat in such a way to face from the cylinder block toward the cylinder head, the oil control valve having a wire outlet joint end facing the cylinder block. 
     
     
         4 . The variable valve lift mechanism for engine and arrangement of oil control valve according to  claim 2 , wherein the oil control valve seat forms an opening, which faces toward the cylinder head, whereby the oil control valve is mounted to the oil control valve seat in such a way to face from the cylinder head toward the cylinder block, the oil control valve having a wire outlet joint end facing toward the cylinder head. 
     
     
         5 . The variable valve lift mechanism for engine and arrangement of oil control valve according to  claim 1 , wherein the cylinder block comprises a timing chain tensioner arranged therein, the oil control valve seat being arranged to be substantially in line with the timing chain tensioner. 
     
     
         6 . The variable valve lift mechanism for engine and arrangement of oil control valve according to  claim 1 , wherein the oil control valve seat and the camshaft base are integrally formed with the cylinder head. 
     
     
         7 . The variable valve lift mechanism for engine and arrangement of oil control valve according to  claim 3 , wherein the oil control valve is mounted to the oil control valve seat and is substantially parallel to a wall of the cylinder head. 
     
     
         8 . The variable valve lift mechanism for engine and arrangement of oil control valve according to  claim 1 , wherein the driving oil passage comprises a first driving oil passageway and a second driving oil passageway corresponding to the hydraulic cylinder, the first driving oil passageway being associated with the low lift driving member, the second driving oil passageway being associated with the high lift driving member. 
     
     
         9 . The variable valve lift mechanism for engine and arrangement of oil control valve according to  claim 1 , wherein the first intake cam is a low lift valve intake cam, the second intake cam being a high lift valve intake cam. 
     
     
         10 . The variable valve lift mechanism for engine and arrangement of oil control valve according to  claim 1 , wherein the engine is arranged substantially horizontally, the oil control valve seat being substantially parallel to an intake tube, the oil control valve being arranged on the cylinder head of the engine in a substantially horizontal manner. 
     
     
         11 . The variable valve lift mechanism for engine and arrangement of oil control valve according to  claim 1 , wherein the primary oil supply passage has an end toward the crankcase, the end forming a crankshaft oil supply passage. 
     
     
         12 . The variable valve lift mechanism for engine and arrangement of oil control valve according to  claim 11 , wherein the crankshaft oil supply passage has an end provided with a throttle arrangement. 
     
     
         13 . The variable valve lift mechanism for engine and arrangement of oil control valve according to  claim 1 , wherein the primary oil supply passage has an end toward a cylinder head cover, the end being provided with a valve driving member oil supply passage. 
     
     
         14 . The variable valve lift mechanism for engine and arrangement of oil control valve according to  claim 13 , wherein the valve driving member oil supply passage is provided with a throttle arrangement. 
     
     
         15 . The variable valve lift mechanism for engine and arrangement of oil control valve according to  claim 12 , wherein the throttle arrangement comprises a nozzle. 
     
     
         16 . The variable valve lift mechanism for engine and arrangement of oil control valve according to  claim 14 , wherein the throttle arrangement comprises a nozzle.