Variable mechanical valve control for an internal combustion engine

1. A variable mechanical valve control for an internal combustion engine having an underhead camshaft for adjusting a valve stroke and an opening and closing time of at least one intake and/or exhaust gas exchange valve, comprising:

a transmission gear and at least one tappet push rod,

a lever driven by a camshaft for actuating the intake and/or exhaust valve,

an intermediate lever linked to a tappet push rod via an axle in such a way that a slide gate roller, which is rotatably mounted on the axle and is driven by the camshaft, is moved in a slide gate, whereby a first contact surface on the intermediate lever is supported on one of an eccentric shaft or a second contact surface and the lever is movable over an operating curve, by means of which the gas exchange valve is opened and/or closed, and whereby, on a tappet provided on the tappet push rod, means are provided for additional shifting of a phase position of valve liftings of the gas exchange valve with simultaneous play-free adjustment of the valve stroke and means are provided for additional independently controllable valve stroke opening and closing for each camshaft revolution,

wherein, depending on a displacement of an axial position of the tappet push rod with the tappet in opposing directions in relation to a central axis of the camshaft, the valve opening time points or the valve closing time points are differently adjustable.

2. The variable mechanical valve control according to claim 1 , wherein the lever is constructed as one of a rocker arm or pivoting lever.

3. The variable mechanical valve control according to claim 1 , wherein one of a path of the slide gate is defined by an arc around a center point of a lever roller and a first portion of the operating curve is defined by an arc around a center point of the slide gate roller.

4. The variable mechanical valve control according to claim 1 , wherein, for an internal combustion engine having at least two intake and/or exhaust valves, the corresponding intermediate levers and the levers have different geometries for valve actuation and are not provided on a common axle.

5. The variable mechanical valve control according to claim 1 , wherein the lever actuates simultaneously two gas exchange valves by way of a valve bridge.

6. The variable mechanical valve control according to claim 1 , wherein the first contact surface of the intermediate lever is a component of a rotatably mounted roller.

7. The variable mechanical valve control according to claim 1 , wherein, for certain geometric positions of components of the transmission gear, a zero stroke of a gas exchange valve is adjusted and thus at least one gas exchange valve for each cylinder is shut down.

8. The variable mechanical valve control according to claim 1 , wherein the tappet is constructed as a pivoting lever between the tappet push rod and the camshaft.

9. The variable mechanical valve control according to claim 8 , wherein, for adjusting the phase position of the valve liftings of the gas exchange valves or of the valve strokes and the valve opening and closing time points, an additional adjusting element is provided on the tappet or pivoting lever.

10. The variable mechanical valve control according to claim 9 , wherein the adjusting element comprises an eccentric shaft with a coupling point and is coupled to the tappet or pivoting lever, whereby, by means of a rotation of the eccentric shaft, a preset change of the phase position and valve liftings of the gas exchange valve is effected.

11. The variable mechanical valve control according to claim 9 , wherein the tappet is linearly adjustable by means of the adjusting element.

12. The variable mechanical valve control according to claim 1 , wherein the adjustment of the intake and exhaust valve liftings with respect to each other is effected separately and differently.

13. The variable mechanical valve control according to claim 1 , wherein the camshaft has at least one secondary cam, by means of which, for each camshaft revolution, a second opening and closing of the intake and/or exhaust valve is effected.

14. The variable mechanical valve control according to claim 1 , wherein, as means for the additional independent valve stroke opening and closing for each camshaft revolution, there is provided a second actuating system for a secondary stroke, whereby, through the second actuating system, the valve opening of the gas exchange valve takes place in a changeable manner and independently from the opening of a primary stroke.

15. The variable mechanical valve control according to claim 1 , wherein a spring is provided for reinforcing a support of the first contact surface on the eccentric shaft or the second contact surface.