Valve train lever
A valve train lever for actuating a valve of a reciprocating piston engine, in particular an internal combustion engine. The valve train lever comprises a lever arm, which is pivotally movable about a pin; a tapping element, which lies against or can be made to lie against a cam of a camshaft of the reciprocating piston engine; a coupling mechanism, by way of which the tapping element is coupled to the lever arm spring-elastically in a first state and rigidly in a second state; and an actuating element, which is connected to the lever arm and lies against or can be made to lie against a valve tappet of the valve.
1. A valve train lever for actuating a valve of a reciprocating piston engine, comprising:
a lever arm, which is pivotally movable about a pin;
a tapping element, which lies against or can be made to lie against a cam of a camshaft of the reciprocating piston engine, wherein the tapping element is arranged movably in a transverse direction, transversely in relation to the lever arm;
a coupling mechanism, by way of which the tapping element is coupled to the lever arm spring-elastically in a first state and rigidly in a second state, wherein the coupling mechanism comprises a pressure piston space and a pressure piston that is movable in the transverse direction and delimits the pressure piston space;
an actuating element, which is connected to the lever arm and lies against or can be made to lie against a valve tappet of the valve; and
a control unit for controlling the first state and the second state of the coupling mechanism, wherein the control unit on an outlet side is in fluid connection with the pressure piston space wherein the control unit on an inlet side is in fluid connection with a control line, wherein the control unit for realizing a pressure intensification comprises a control piston with an inlet-side effective surface and an outlet-side effective surface, the outlet side effective surface is smaller than the inlet-side effective surface, wherein the control unit in a first state connects the outlet side in fluid connection with the pressure piston space to a relief line.
2. The valve train lever according to claim 1 , wherein, at least in the second state, the pressure piston interacts with the tapping element and, in the second state, the pressure piston space is filled with a hydraulic fluid.
3. The valve train lever according to claim 1 , wherein the coupling mechanism comprises a pressure spring, which is supported on the lever arm and prestresses the tapping element in the transverse direction.
4. The valve train lever according to claim 3 , wherein the pressure piston interacts with the tapping element in the first state and in the second state, and the pressure spring is arranged in the pressure piston space and lies against the pressure piston.
5. The valve train lever according to claim 3 , wherein the pressure spring lies against the tapping element.
6. The valve train lever according to claim 5 , wherein the coupling mechanism comprises a counterpressure spring, which is supported on the tapping element and prestesses the pressure piston in the transverse direction, and, in the first state, the tapping element is kept at a distance from the pressure piston in the transverse direction.
7. The valve train lever according to claim 1 , wherein the tapping element comprises a roller tappet.
8. The valve train lever according to claim 1 , wherein a longitudinal direction of movement of the tapping element and a longitudinal direction of movement of the control piston are coaxial.
9. A reciprocating piston engine, in particular an internal combustion engine, comprising:
a valve train lever for actuating a valve of the reciprocating piston engine, the valve train lever including,
a lever arm, which is pivotally movable about a pin;
a tapping element, which lies against or can be made to lie against a cam of a camshaft of the reciprocating piston engine, wherein the tapping element is arranged movably in a transverse direction, transversely in relation to the lever arm;
a coupling mechanism, by way of which the tapping element is coupled to the lever arm spring-elastically in a first state and rigidly in a second state, wherein the coupling mechanism comprises a pressure piston space and a pressure piston that is movable in the transverse direction and delimits the pressure piston space;
an actuating element, which is connected to the lever arm and lies against or can be made to lie against a valve tappet of the valve; and
a control unit for controlling the first state and the second state of the coupling mechanism, wherein the control unit on an outlet side is in fluid connection with the pressure piston space wherein the control unit on an inlet side is in fluid connection with a control line, wherein the control unit for realizing a pressure intensification comprises a control piston with an inlet-side effective surface and an outlet-side effective surface, the outlet side effective surface is smaller than the inlet-side effective surface, wherein the control unit in a first state connects the outlet side in fluid connection with the pressure piston space to a relief line.
10. A reciprocating piston engine according to claim 9 , wherein the control unit is in fluid connection on an inlet side with an oil circuit of the reciprocating piston engine by way of a solenoid valve.
11. A motor vehicle, in particular a commercial vehicle, with an internal combustion engine comprising:
a valve train lever for actuating a valve of a reciprocating piston engine, the valve train lever including,
a lever arm, which is pivotally movable about a pin;
a tapping element, which lies against or can be made to lie against a cam of a camshaft of the reciprocating piston engine, wherein the tapping element is arranged movably in a transverse direction, transversely in relation to the lever arm;
a coupling mechanism, by way of which the tapping element is coupled to the lever arm spring-elastically in a first state and rigidly in a second state, wherein the coupling mechanism comprises a pressure piston space and a pressure piston that is movable in the transverse direction and delimits the pressure piston space;
an actuating element, which is connected to the lever arm and lies against or can be made to lie against a valve tappet of the valve; and
a control unit for controlling the first state and the second state of the coupling mechanism, wherein the control unit on an outlet side is in fluid connection with the pressure piston space wherein the control unit on an inlet side is in fluid connection with a control line, wherein the control unit for realizing a pressure intensification comprises a control piston with an inlet-side effective surface and an outlet-side effective surface, the outlet side effective surface is smaller than the inlet-side effective surface, wherein the control unit in a first state connects the outlet side in fluid connection with the pressure piston space to a relief line.