Mechanically controllable valve drive

Abstract

A mechanically controllable valve drive includes a cylinder head, a valve lift adjustment device comprising a rocker arm, a pivoted lever assembly comprising an end surface, an engagement element, and a bearing means. The pivoted lever assembly is mounted in the cylinder head via the bearing means so as to be movable. A gas exchange valve is configured to have the pivoted lever assembly act thereon via the end surface. A positioning device is configured to engage on the rocker arm. A valve clearance is arranged between the rocker arm and the engagement element. At least one adjustment device is configured to provide a valve clearance adjustment. The engagement element of the pivoted lever assembly is operatively connected to the rocker arm of the valve lift adjustment device via a work curve.

What is claimed is: 
     
         1 - 18 . (canceled) 
     
     
         19 . A mechanically controllable valve drive comprising:
 a cylinder head;   a valve lift adjustment device comprising a rocker arm;   a pivoted lever assembly comprising an end surface, an engagement element, and a bearing means, the pivoted lever assembly being mounted in the cylinder head via the bearing means so as to be movable;   a gas exchange valve configured to have the pivoted lever assembly act thereon via the end surface;   a positioning device configured to engage on the rocker arm;   a valve clearance arranged between the rocker arm and the engagement element; and   at least one adjustment device configured to provide a valve clearance adjustment,   wherein, the engagement element of the pivoted lever assembly is operatively connected to the rocker arm of the valve lift adjustment device via a work curve.   
     
     
         20 . The valve drive as recited in  claim 19 , wherein the positioning element is a spring element. 
     
     
         21 . The valve drive as recited in  claim 20 , wherein the engagement element is a roll, and further comprising, a camshaft, a sliding block assembly, and an adjustment member,
 wherein, the valve lift adjustment device is configured so that the rocker arm is movable via the roll and the camshaft in the sliding block assembly and to be pivotable via the adjustment member,   wherein, a side facing the pivoted lever assembly comprises the work curve operatively connected to the engagement element, and   wherein, the rocker arm is biased by the spring member.   
     
     
         22 . The valve drive as recited in  claim 19 , wherein the rocker arm is configured as an L-shape comprising a work curve leg and a guide leg, and the positioning device is a spring member comprising at least one spring force component in a direction of the guide leg. 
     
     
         23 . The valve drive as recited in  claim 22 , wherein the spring member is configured to engage on the work curve leg. 
     
     
         24 . The valve drive as recited in  claim 19 , further comprising a pivot axle, Wherein the bearing means of the pivoted lever assembly is a pivot bearing arranged on the pivot axle. 
     
     
         25 . The valve drive as recited in  claim 19 , wherein the at least one adjustment device is provided between the gas exchange valve and the end surface. 
     
     
         26 . The valve drive as recited in  claim 25 , wherein the at least one adjustment device is configured as an adjustment disk comprising a stepped thickness. 
     
     
         27 . The valve drive as recited in  claim 24 , wherein the at least one adjustment device is arranged in the pivot bearing. 
     
     
         28 . The valve drive as recited in  claim 19 , wherein the at least one adjustment device is provided in the valve lift adjustment device. 
     
     
         29 . The valve drive as recited in  claim 19 , wherein the pivoted lever assembly further comprises a pivoted lever and a roll rotatably supported in the pivoted lever, the roll being configured so as to be operatively connected to the work curve of the rocker arm. 
     
     
         30 . The valve drive as recited in  claim 19 , wherein the at least one adjustment device is the pivoted lever assembly. 
     
     
         31 . The valve drive as recited in  claim 30 , wherein at least one adjustment device is the roil of the pivoted lever assembly. 
     
     
         32 . The valve drive as recited in  claim 21 , wherein the at least one adjustment device is provided via the adjustment member. 
     
     
         33 . The valve drive as recited in  claim 19 , wherein the at least one adjustment device is provided via the work curve of the rocker arm. 
     
     
         34 . The valve drive as recited in  claim 21 , wherein the work curve comprises a first curve section and a second curve section which are configured to provide for the valve clearance, the first curve section being assigned to a cold operating condition of an internal combustion engine and the second curve section being assigned to a heated operating condition of the internal combustion engine. 
     
     
         35 . The valve drive as recited in  claim 34 , wherein the valve clearance is configured to be adjustable based on a temperature between the work curve and the engagement element by rotating the adjustment member. 
     
     
         36 . ne valve drive as recited in  claim 21 , wherein the at least one adjustment device is provided via the sliding block assembly. 
     
     
         37 . A mechanically controllable valve drive assembly comprising:
 a mechanically controllable valve drive as recited in  claim 21 ;   a plurality of gas exchange valves arranged in a row, the plurality of gas exchange valves comprising corresponding cylinders assigned thereto, each gas exchange valve having a respective mechanically controllable valve drive assigned thereto;   a stud axle;   a camshaft;   a sliding block assembly;   rocker arms comprising guide rolls, the guide rolls being configured to guide the rocker arm in the sliding block assembly, the guide rolls of two adjacent rocker arms being connected to each other via the stud axle; and   a guide roll arranged between the guide rolls, the guide roll being configured to have the camshaft engage thereon.