Structure of driving member of engine valve

Abstract

An engine includes a camshaft carrying a first intake cam, a second intake cam, and an exhaust cam for selectively driving an intake valve driving member and an exhaust valve driving member, which in turn drive an intake valve and an exhaust valve. The intake valve driving member includes first and second driving members, which form push rollers respectively in engagement with the first and second intake cams and a pressing section in engagement with the intake valve. The first and second driving members form bores communicating each other to form a hydraulic cylinder. First and second pistons are movable within the bores to selectively set the first and second driving members in a condition of being allowed to operate independently or in combination with each other.

1 . A driving member of valve of engine, the engine comprising a crankcase, a cylinder block mounted on the crankcase, and a cylinder head mounted on the cylinder block, the cylinder head comprising an intake port and an intake valve and an exhaust port and an exhaust valve, a camshaft seat being arranged between the intake valve and the exhaust valve, the camshaft seat comprising a camshaft that is driven by a timing chain, the camshaft comprising a first intake cam, a second intake cam, and an exhaust cam mounted thereto, whereby through the first intake cam, the second intake cam, and the exhaust cam, the camshaft, when put in rotation, drives an intake valve driving member or an exhaust valve driving member, and further, through the intake valve driving member or the exhaust valve driving member, the intake valve or the exhaust valve is caused to operate, characterized in that the intake valve driving member comprises a first driving member and a second driving member, the first driving member forming a positioning hole, a bore, and a push roller, the second driving member forming a positioning hole, a bore, a push roller, and a pressing section, the positioning holes of the first driving member and the second driving member receiving extension of a shaft rod therethrough, the push roller of the first driving member being in engagement with the first intake cam, the push roller of the second driving member being in engagement with the second intake cam, the pressing section of the second driving member being in engagement with the intake valve, the bore of the first driving member and the bore of the second driving member being in communication with each other to form a hydraulic cylinder, whereby the hydraulic cylinder allows the first driving member and the second driving member to operate independent of each other in a low lift opening condition of the intake valve and allows the first driving member and the second driving member to operatively connect to each other in a high lift opening condition of the intake valve. 
     
     
         2 . The valve driving member of engine according to  claim 1 , wherein the cylinder head comprises an oil control valve. 
     
     
         3 . The valve driving member of engine according to  claim 1 , wherein the cylinder head comprises a position-constraining mechanism in pushing engagement with the first driving member and the second driving member, the position-constraining mechanism comprising a position-constraining rod, a spring, and a pressure relief hole. 
     
     
         4 . The valve driving member of engine according to  claim 3 , wherein the first driving member and the second driving member comprise positioning bars, the positioning bars being in pushing engagement with the position-constraining rod of the position-constraining mechanism. 
     
     
         5 . The valve driving member of engine according to  claim 4 , wherein the positioning bars of the first driving member and the second driving member are located between the positioning holes and the pressing section. 
     
     
         6 . The valve driving member of engine according to  claim 1 , wherein the bores of the first driving member and the second driving member are located between the push rollers and the positioning holes and are located above a center-connection line connecting between centers of the push rollers and the positioning holes. 
     
     
         7 . The valve driving member of engine according to  claim 1 , wherein the first driving member and the second driving member are formed integrally. 
     
     
         8 . The valve driving member of engine according to  claim 4 , wherein the first driving member and the second driving member are formed integrally. 
     
     
         9 . The valve driving member of engine according to  claim 6 , wherein the first driving member and the second driving member are formed integrally. 
     
     
         10 . The valve driving member of engine according to  claim 1 , wherein the pressing section comprises a gap adjusting member. 
     
     
         11 . The valve driving member of engine according to  claim 5 , wherein the pressing section comprises a gap adjusting member. 
     
     
         12 . The valve driving member of engine according to  claim 1 , wherein the hydraulic cylinder has two ends respectively closed by closure caps and receives therein a spring, the first piston, and the second piston. 
     
     
         13 . The valve driving member of engine according to  claim 12 , wherein the first piston forms a first recess and a second recess. 
     
     
         14 . The valve driving member of engine according to  claim 13 , wherein the closure caps form projecting pegs projecting inward of the hydraulic cylinder.