Hydraulic valve play compensating element for reciprocating-piston internal combustion engines

Abstract

A reciprocating-piston internal combustion engine which operates on the four-stroke cycle, having a crankcase and having at least one cylinder which is arranged in said crankcase and in which a piston is guided by a crankshaft, having at least one cylinder head which closes off the cylinder and the intake and exhaust channels which are controlled by at least in each case one intake and exhaust valve loaded by a valve spring, which intake and exhaust valves can be actuated by transmission elements driven by a camshaft, and having a hydraulic valve play compensating element ( 5 ) which is installed in at least one of the transmission elements or in a component, which is installed in the transmission element, between the camshaft and at least one intake and/or exhaust valve, which hydraulic valve play compensating element has a working piston ( 8 ), a cylinder housing ( 7 ) which interacts with the working piston ( 8 ), a restoring spring ( 18 ) which is installed in between, and a check valve which delimits a high-pressure chamber ( 19 ) and the valve closing body ( 12 ) of which corresponds to a valve seat ( 11 ) on the working piston ( 8 ). The valve closing body ( 12 ) has a partial spherical surface ( 13 ) in a region of the valve seat ( 11 ), and a ratio of the diameter of the working piston ( 8 ) to twice the radius of the partial spherical surface ( 13 ) is ≦2.

1 . A four stroke reciprocating piston internal combustion engine comprising a crankcase and at least one cylinder arranged in said crankcase, a piston is guided in the cylinder by a crankshaft, at least one cylinder head closing said cylinder, intake and exhaust channels of said cylinder head being controlled in each case by at least one intake and exhaust valve loaded by a valve spring, said intake and exhaust valves being actuated by transmission elements driven by a camshaft, a hydraulic valve lash adjusting element is installed in at least one of said transmission elements or in a component which is installed in the transmission element between the camshaft and at least one of the intake or exhaust valves, the hydraulic valve lash adjusting element comprising a working piston, a cylinder housing interacting with said working piston, a resetting spring arranged in between, and a non-return valve which delimits a high pressure chamber, and a valve closing body of said non-return valve corresponding to a valve seat on said working piston, the valve closing body comprises a partial spherical surface in a region of the valve seat and a ratio of a diameter of the working piston to twice a radius of the partial spherical surface is ≦2. 
     
     
         2 . A four stroke reciprocating piston internal combustion engine comprising a crankcase and at least one cylinder arranged in said crankcase, a piston is guided in the cylinder by a crankshaft, at least one cylinder head closing said cylinder, intake and exhaust channels of said cylinder head being controlled in each case by at least one intake and outlet valve loaded by a valve spring, said intake and exhaust valves being actuated by transmission elements driven by a camshaft, a hydraulic valve lash adjusting element is installed in at least one of said transmission elements or in a component which is installed in the transmission element between the camshaft and at least one of the intake or exhaust valves, a hydraulic valve lash adjusting element comprising a working piston, a cylinder housing interacting with said working piston, a resetting spring arranged in between, and a non-return valve which delimits a high pressure chamber, and a valve closing body of said non-return valve corresponding to a valve seat on said working piston, the valve closing body comprises in a region of the valve seat, a partial spherical surface which is adjoined by a cylindrical peripheral surface. 
     
     
         3 . A four stroke reciprocating piston internal combustion engine comprising a crankcase and at least one cylinder arranged in said crankcase, a piston is guided in the cylinder by a crankshaft, at least one cylinder head closing said cylinder, intake and exhaust channels of said cylinder head being controlled in each case by at least one intake and exhaust valve loaded by a valve spring, said intake and exhaust valves being actuated by transmission elements driven by a camshaft, a hydraulic valve lash adjusting element is installed in at least one of said transmission elements or in a component which is installed in the transmission element between the camshaft and at least one of the intake or exhaust valves, said engine further comprising a hydraulic valve lash adjusting element comprising a working piston, a cylinder housing interacting with said working piston, a resetting spring arranged in between, and a non-return valve which delimits a high pressure chamber, and a valve closing body of said non-return valve corresponding to a valve seat on said working piston, a diameter of the valve seat is ≧5.0 mm. 
     
     
         4 . A four stroke reciprocating piston internal combustion engine comprising a crankcase and at least one cylinder arranged in said crankcase, a piston is guided in the cylinder by a crankshaft, at least one cylinder head closing said cylinder, intake and exhaust channels of said cylinder head being controlled in each case by at least one intake and exhaust valve loaded by a valve spring, said intake and exhaust valves being actuated by transmission elements driven by a camshaft, said engine further comprising a hydraulic valve lash adjusting element is installed in at least one of said transmission elements or in a component which is installed in the transmission element between the camshaft and at least one of the intake or exhaust valves, a hydraulic valve lash adjusting element comprising a working piston, a cylinder housing interacting with said working piston, a resetting spring arranged in between, and a non-return valve which delimits a high pressure chamber, and a valve closing body of said non-return valve corresponding to a valve seat on said working piston, a diameter of the valve closing body is ≧7.5 mm. 
     
     
         5 . A four stroke reciprocating piston internal combustion engine comprising a crankcase and at least one cylinder arranged in said crankcase, a piston is guided in the cylinder by a crankshaft, said engine further comprising at least one cylinder head closing said cylinder, intake and exhaust channels of said cylinder head being controlled in each case by at least one intake and exhaust valve loaded by a valve spring, said intake and exhaust valves being actuated by transmission elements driven by a camshaft, said engine further comprising a hydraulic valve lash adjusting element is installed in at least one of said transmission elements or in a component which is installed in the transmission element between the camshaft and at least one of the intake or exhaust valves, a hydraulic valve lash adjusting element comprising a working piston, a cylinder housing interacting with said working piston, a resetting spring arranged in between, and a non-return valve which delimits a high pressure chamber, and a valve closing body of said non-return valve corresponding to a valve seat on said working piston, the valve closing body comprises a partial spherical surface, a pocket hole turned away from the high pressure chamber is arranged in a region of the partial spherical surface. 
     
     
         6 . A reciprocating piston internal combustion engine according to  claim 1 , wherein the radius of the partial spherical surface is ≧2.5 mm. 
     
     
         7 . A reciprocating piston internal combustion engine according to  claim 2 , wherein adjoining the cylindrical peripheral surface, the valve closing body comprises a peg. 
     
     
         8 . A reciprocating piston internal combustion engine according to  claim 7 , wherein the peg is surrounded by a valve closing spring that is further supported in an opening of a valve cap. 
     
     
         9 . A reciprocating piston internal combustion engine according to  claim 8 , wherein a bore, is arranged adjoining the opening in the valve cap. 
     
     
         10 . A reciprocating piston internal combustion engine according to  claim 8 , wherein the valve cap is configured with a stepped inner diameter, having a large inner diameter surrounding the cylindrical peripheral surface of the valve closing body and a smaller diameter surrounding the valve closing spring. 
     
     
         11 . A reciprocating piston internal combustion engine according to  claim 10 , wherein beads or openings are arranged on the valve cap in a region of the large diameter and extend from the high pressure chamber to the valve seat.