EP3401517A1 - Valve gear lever - Google Patents

Abstract

A valve train lever (100) for actuating a valve of a reciprocating engine, in particular an internal combustion engine is described. The valve drive lever (100) comprises a lever arm (102) pivotable about an axis (104); a tapping element (106) abutting or coming into contact with a cam of a camshaft of the reciprocating engine; a coupling mechanism (110) via which the tapping element (106) is resiliently coupled to the lever arm (102) in a first state and rigidly in a second state; and an actuator (120) connected to the lever arm (102) and engaging or abutting a valve lifter of the valve.

Description

The present invention relates to a valve train lever for actuating a valve of a reciprocating engine, in particular an internal combustion engine. In particular, but not limited to, a valve train lever for actuating a valve for removing compressed gases, in particular compressed air, from a combustion chamber of the internal combustion engine and an engine equipped with such a valve train lever disclosed.

The internal combustion engine of a motor vehicle, in particular a commercial vehicle, can be used for compressed air supply. For example, in overrun or engine braking operation with nichtfefeuerter internal combustion engine, these can be used as a compressor for generating the compressed air. Furthermore, compressed gases can be taken from the combustion chamber of the internal combustion engine at defined operating cycles.

The publication AT 514127 A1 describes a valve via which air is discharged at applied in the combustion chamber pressure. The valve is periodically opened by a cam via a rocker arm at defined operating cycles of the internal combustion engine. In the cam-side arm of the rocker arm, a piston-cylinder unit is integrated, the piston cooperates via a roller tappet with the cam. When pressure is applied in the pressure chamber of the piston-cylinder unit, the rocker arm is effective. In the depressurized state of the piston-cylinder unit, the rocker arm is not actuated and the valve remains closed.

However, the previously known rocker arm assumes no defined position in the depressurized state of the piston-cylinder unit. This is disadvantageous for the efficiency of the internal combustion engine and also for running noise and wear. In particular, the conventional rocker arm in the pressureless state ensures no continuous rolling contact between roller tappet and cam.

Another disadvantage of the conventional rocker arm is its moment of inertia. In the pressurized state, the piston-cylinder unit must also transmit the inertial forces of the rocker arm. This is generally not ensured by a larger dimensioning of the piston-cylinder unit, as it also increases the moment of inertia of the rocker arm. Also, the available for pressurizing lubricating oil pressure of the internal combustion engine is given by the operating state, and may be less than 1 bar in idle mode.

Thus, the object is to provide a technique for actuating the valve that improves efficiency, running noise and / or wear. Another or alternative object is to control the actuation of the valve by means of the oil pressure available for a reciprocating engine.

This object or objects are achieved by a valve train lever for actuating a valve of a reciprocating engine, in particular an internal combustion engine, and a correspondingly equipped reciprocating engine according to the independent claims.

In one aspect, a valvetrain lever includes a lever arm pivotable about an axis; a pick-up member abutting or engageable with a cam of a camshaft of the reciprocating engine; a coupling mechanism via which the tapping element is resiliently coupled to the lever arm in a first state and rigidly coupled in a second state; and an actuator connected to the lever arm and engaging or abutting a valve lifter of the valve.

Due to the elastic coupling in the first state of the lever arm can assume a rest position, while the tapping element follows due to the spring elasticity of a contour of the cam. The first state may also be referred to as idle state of the valve train lever. In the second state, the valve of the reciprocating engine can be actuated due to the rigid coupling by the rigid coupling of the tapping element causes the pivoting movement of the lever arm and thus the actuation by the actuating element.

By lever arm and actuator occupy a rest position in the first state, running noise and / or power losses can be reduced. While the lever arm and the actuating element remain in the rest position in the first state, the tapping element can follow the reduction of power losses, running noises and / or wear due to the spring-elastic coupling of the cam contour.

The reciprocating engine may be an internal combustion engine. The reciprocating engine may be stationary or mobile.

The valve train lever may be formed as a rocker arm. The tapping element can be arranged at a first end of the rocker arm. The actuating element can be arranged on a first end opposite the second end of the rocker arm. On or in the lever arm, a pivot bearing for pivotal movement of the rocker arm between be arranged at the first end and the second end. Alternatively, the valve train lever may be designed as a drag lever. The tapping element can be arranged at a first position of the finger lever. The actuating element can be arranged at a second position of the finger lever which is different from the first position. On or in the lever arm, a pivot bearing can be arranged for the pivoting movement of the finger lever. The first location may be located between the pivot bearing and the second location. Alternatively, the second location may be located between the pivot bearing and the first location.

The tapping element may be arranged to be movable transversely to the lever arm in a transverse direction, for example by a guide on the lever arm. Alternatively or additionally, the tapping element can be arranged immovably in a longitudinal direction that is different from the transverse direction (for example transversely to the transverse direction, in particular parallel to the lever arm).

The tapping element can be biased towards the cam in the first state and in the second state and / or rest on the cam. The coupling mechanism may include a pressure piston space and a transversely movable pressure piston in the pressure piston space. The pressure piston can limit the pressure piston space.

The pressure piston can cooperate with the tapping element at least in the second state. In the second state, the pressure piston can cooperate with the tapping element in that the pressure piston rests on the tapping element in the second state, for example on a side of the tapping element facing the lever arm.

The pressure piston chamber can be filled with a hydraulic fluid in the second state. The hydraulic fluid may be (at least substantially) incompressible. The hydraulic fluid may include oil, in particular lubricating oil of the reciprocating engine.

The tapping element may be biased in the transverse direction, for example away from the lever arm and / or toward the cam. The coupling mechanism may comprise a compression spring supported on the lever arm. The compression spring may bias the tapping element in the transverse direction.

The pressure piston can cooperate in the first state and in the second state with the tapping element. The pressure piston can cooperate in the first and second state with the tapping element by the pressure piston rests on the tapping element, for example on a side facing the lever arm of the tapping element. Alternatively, the pressure piston may be connected to the tapping element. The plunger and the tapping member may be immovable relative to one another in the transverse direction.

The compression spring can be arranged in the pressure piston chamber. The compression spring can rest on the pressure piston. The pressure piston and the tapping element can follow the contour of the cam together in the first state and in the second state.

Alternatively or additionally, the compression spring, or a further compression spring, abut the tapping element.

The plunger may be biased in the transverse direction, for example towards the lever arm and / or away from the tap element. The coupling mechanism may comprise a counter-pressure spring supported on the tapping element. The counter-pressure spring can be arranged between the tapping element and the pressure piston. The counterpressure spring may bias the plunger in the transverse direction. Alternatively or additionally, the pressure piston may be biased by a tension spring fastened on the one hand to the lever arm and on the other hand to the pressure piston.

In the first state, the tapping element may be spaced from the pressure piston in the transverse direction, for example because of the bias of the counter-pressure spring and / or tension spring. Alternatively or additionally, in the first state of the pressure piston abut a lever near or proximal stop and / or the pressure piston chamber can assume a minimum size.

In the second state, due to a volume and / or a pressure of the hydraulic fluid in the pressure piston space against the bias, the counter-pressure spring can be contracted and / or the tension spring can be stretched. In the second state, the pressure piston can rest against a lever-distal or distal stop and / or the pressure piston chamber can assume a maximum size.

The tapping element can follow the contour of the cam in the first state and in the second state. For example, in the first state, only the tapping element can follow the contour of the cam. The pressure piston can rest in the first state. The pressure piston can rest in the first state and in the second state in each case relative to the lever arm.

The tapping element may comprise a roller tappet. The roller tappet may comprise a cam start roller.

The valve train lever may further comprise a control unit for controlling the first state and the second state of the coupling mechanism. The control unit may be on the output side in fluid communication with the pressure piston chamber. The control unit may be in fluid communication with a control line on the input side.

The control unit may comprise a check valve and / or a hydraulic pressure booster. The check valve can open in the flow direction from the input side to the output side of the control unit, and vice versa.

The control unit may comprise a control piston with an input-side active surface and an output-side effective surface, for example for realizing the pressure intensification and / or for closing a discharge line. The output-side effective area may be smaller than the input-side effective area. The hydraulic pressure transmission can translate an input-side pressure (control pressure) into a larger output-side pressure, for example for pressurizing the pressure piston chamber in the second state. The hydraulic pressure booster and the check valve can be connected in parallel.

In the first state, the control unit can connect the output-side fluid connection to the pressure piston chamber with the unloading power. In the second state, the control unit can close the outlet-side fluid connection to the pressure piston chamber. In the second state, the control unit can keep the outlet-side fluid connection to the pressure piston chamber closed against the larger output-side pressure.

The control unit can be on the input side via a solenoid valve optionally in fluid communication with the oil circuit of the reciprocating engine. The solenoid valve may be arranged in the control line. When the solenoid valve is closed, the control unit can bring about the first state. When the solenoid valve is open, the control unit can cause the second state.

Optionally, the actuator may be in fluid communication (eg, in the second state) with the oil circuit of the reciprocating engine, for example, via the same solenoid valve. The actuating element may comprise a ball-head connection and / or an actuating surface.

The tapping element, for example the roller tappet, may be permanently (eg, in the first and second states) in fluid communication with the oil circuit of the reciprocating engine.

The control unit may be arranged on the coupling mechanism or on a pivot bearing of the pivotable lever arm. The fluid connection or fluid connections between the control unit and the coupling mechanism may include holes in the lever arm.

Such a valve train lever can be used in a reciprocating engine, in particular an internal combustion engine or a compressor, for compressing a gas by selective actuation of the valve of the reciprocating engine.

In another aspect, there is provided a reciprocating engine, particularly an internal combustion engine, which includes a valvetrain lever according to the first aspect. The reciprocating piston engine may comprise a valve for the periodic removal of a compressed gas from a compression chamber of the reciprocating piston engine, for example a combustion chamber of the internal combustion engine. The reciprocating engine may further include a camshaft having at least one cam for selectively actuating the valve via the valvetrain lever. Actuation of the valve may be selective by controlling the coupling mechanism of the valve train lever. In the first state, the operation can be omitted. In the second state, the operation may be performed periodically in accordance with the cam.

Such a reciprocating engine, for example an internal combustion engine and / or a corresponding device for generating compressed air, can be used stationary or in a motor vehicle. A primary function of the internal combustion engine may be the drive of the motor vehicle. A secondary function of the internal combustion engine may be the compression of the gas, for example the generation of compressed air.

Another aspect relates to a motor vehicle with such an internal combustion engine. The motor vehicle may be a land vehicle, a watercraft or an aircraft. The motor vehicle may be used for the transport of goods and / or passenger transport. In particular, the motor vehicle may be a commercial vehicle (for example a lorry or a bus) or a passenger car. That provided by the valve in the second state compressed gas, for example the compressed air, may be supplied to a brake system and / or an air spring of the motor vehicle.

Figur 1

eine schematische Darstellung eines ersten Ausführungsbeispiels eines Ventiltriebhebels in einem federelastischen ersten Zustand zu einem ersten Zeitpunkt;

Figur 2

eine schematische Darstellung des ersten Ausführungsbeispiels des Ventiltriebhebels im federelastischen ersten Zustand zu einem zweiten Zeitpunkt;

Figur 3

eine schematische Darstellung des ersten Ausführungsbeispiels des Ventiltriebhebels in einem starren zweiten Zustand zu einem ersten Zeitpunkt;

Figur 4

eine schematische Darstellung des ersten Ausführungsbeispiels des Ventiltriebhebels im starren zweiten Zustand zu einem zweiten Zeitpunkt;

Figur 5

eine schematische Darstellung eines zweiten Ausführungsbeispiels des Ventiltriebhebels mit einer Steuereinheit, die mit jedem Ausführungsbeispiel kombinierbar ist;

Figur 6

eine schematische perspektivische Darstellung eines dritten Ausführungsbeispiels des Ventiltriebhebels, bei dem die Steuereinheit beim Abgriffselement angeordnet ist;

Figur 7

eine schematische Schnittdarstellung des dritten Ausführungsbeispiels in einer Schwenkebene;

Figur 8

einen vergrößerten Ausschnitt der Schnittdarstellung des dritten Ausführungsbeispiels im eingebauten Zustand;

Figur 9

eine schematische Schnittdarstellung eines vierten Ausführungsbeispiels des Ventiltriebhebels in der Schwenkebene; und

Figur 10

eine schematische perspektivische Darstellung eines fünften Ausführungsbeispiels des Ventiltriebhebels, bei dem die Steuereinheit achsennah angeordnet ist.

The features described above can be realized in any combination. Further features and advantages of the invention will be described below with reference to the accompanying drawings. Show it:

FIG. 1

a schematic representation of a first embodiment of a valve train lever in a resilient first state at a first time;

FIG. 2

a schematic representation of the first embodiment of the valve train lever in the spring-elastic first state at a second time;

FIG. 3

a schematic representation of the first embodiment of the valve train lever in a rigid second state at a first time;

FIG. 4

a schematic representation of the first embodiment of the valve train lever in the rigid second state at a second time;

FIG. 5

a schematic representation of a second embodiment of the valve train lever with a control unit, which can be combined with each embodiment;

FIG. 6

a schematic perspective view of a third embodiment of the valve train lever, wherein the control unit is arranged at the tapping element;

FIG. 7

a schematic sectional view of the third embodiment in a pivot plane;

FIG. 8

an enlarged section of the sectional view of the third embodiment in the installed state;

FIG. 9

a schematic sectional view of a fourth embodiment of the valve train lever in the pivoting plane; and

FIG. 10

a schematic perspective view of a fifth embodiment of the valve train lever, in which the control unit is arranged close to the axis.

FIG. 1 schematically shows a first embodiment of a generally designated by the reference numeral 100 valve train lever for actuating a valve 122 of a reciprocating engine, in particular an internal combustion engine. The valve drive lever 100 comprises a lever arm 102 which is pivotable about a pivot axis 104. At a first location of the lever arm 102, a tapping member 106 is disposed via a coupling mechanism 110 for cooperation with a cam 108 of the reciprocating engine. The coupling mechanism 110 includes a pressure piston chamber 112 for receiving a hydraulic fluid, such as lubricating oil. The tapping element 106 and / or a pressure piston arranged in the pressure piston chamber 112 has a longitudinal groove into which an anti-rotation device 116 of the lever arm 102 engages. Optionally, by pressurizing the hydraulic fluid, a shoulder 114 on the tapping member 106 or an associated member (eg, the pressure piston) abuts a stop (which is, for example, identical to the anti-rotation device 116) of the lever arm 102 or an associated member. The coupling mechanism 110 further includes a compression spring 118 which is supported on the one hand on the lever arm 102 or an element connected thereto and on the other hand on the Abgriffselement 106 or an associated element (eg the pressure piston) is applied. The compression spring 118 may in particular be a spiral spring or a wave spring.

In a first resilient state of the coupling mechanism 110, the pressure piston chamber 112 is depressurized, so that the tapping element 106 follows the contour of the cam 108 due to the spring tension of the spring 118. For this purpose, the spring tension is dimensioned such that at a maximum speed, the inertial force of the Abgriffselements 106 is smaller than the spring tension of the compression spring 118th

FIG. 1 shows the resilient first state of the coupling mechanism 110 at a first rotational position of the cam 108. FIG. 2 shows the first embodiment in the same first state at a second rotational position of the cam 108, in which the tip of the cam 108, the tapping element 106 to the lever arm 102 leads to reduction of the pressure piston chamber 112 and compression of the compression spring 118. Thus, the lever arm 102 and the remains at a second position of the lever arm 102 arranged actuator 120 for actuating the valve 122 in a rest position.

In a first embodiment, the rest position due to a bias of a valve stem 124 of the valve 122 is held against the smaller spring tension of the compressed spring 118. In a second embodiment, the pivotal movement of the lever arm 102 is blocked, braked or damped about the pivot axis 104 in the first state. In a third Embodiment, the lever arm 112 is maintained due to its moment of inertia with respect to the pivot axis 104 substantially in the rest position, for example by a resonant frequency or natural frequency of the spring-elastic coupled lever arm 102 is small compared to the rotational speed of the cam 108. The three embodiments are paired or fully combinable.

In one in the FIGS. 3 and 4 schematically shown second state of the pressure piston chamber 112 is filled (optionally in its maximum extent at concern of paragraph 114 at stop 116) with the hydraulic fluid. In the second state of the coupling mechanism 110, the tapping element 106 is rigidly coupled to the lever arm 112 via the hydraulic fluid, for example by a pressure of the hydraulic fluid is given via a fluid connection in the pressure piston chamber 112 or by a fluid drain from the pressure piston chamber 112 is interrupted.

Due to the rigid coupling between the tapping element 106 and the lever arm 102 in the second state of the coupling mechanism 110, the movement of the tapping element 106 following the cam 108 is transmitted via the lever arm 102 and the actuating element 120 to the valve tappet 124 of the valve 122. The pivoting movement 126 about the pivot axis 104 in the second state and the resulting operation 128 of the valve 122 is in the FIGS. 3 and 4 shown. At the in FIG. 3 shown first rotational position of the cam 108, the lever arm 102 in a first pivot position. At the in FIG. 4 shown second rotational position of the cam 108 whose tip cooperates with the rigidly coupled Abgriffselement and guides the lever arm 102 in a different from the first pivot position second pivot position.

In each embodiment, the lever arm 102 may be formed as a rocker arm with the coupling mechanism 110 and the actuator 120 at each different Teilhebelarms with respect to the pivot axis 104. Alternatively, the lever arm 102 may be formed as a finger lever, wherein the coupling mechanism 110 and the actuator 120 on the same side with respect the pivot axis 104 are arranged.

FIG. 5 schematically shows a second embodiment of the valve train lever 100 with a control unit 130 for selectively controlling the first and second state of the coupling mechanism 110. Equivalent or interchangeable features of the second embodiment are denoted by the same reference numerals as in FIGS. 1 to 4 of the first embodiment Mistake. The control unit 130 of the second embodiment can be combined with any further embodiment.

The control unit 130 comprises a check valve 132 with a closing element 134 which opens in the direction of supply to the pressure piston chamber 112 and closes in the direction of flow from the pressure piston chamber 112. The control unit 130 further comprises a control piston chamber 136 (for example, in a cylinder) in which a control piston 138 is arranged longitudinally movable. The control piston 138 delimits the control piston chamber 136 with an input-side effective surface 140. An output side of the control piston 138 opposite the input side is in fluid communication with the pressure piston chamber 112 via a fluid connection 144. On the output side, the control piston 138 or a closing element abutting on the control piston 138 is thereto designed to close the cross-section of a valve seat via an output-side active surface 142.

The input-side effective area 140 (for example with _a cross-sectional area A) is greater than the output side effective area 142 (e.g., with cross-sectional area A _of). Is the input-side effective area 140 by an in fluid communication with the control piston chamber 136 control line 146 is pressurized (for example with a control pressure P _Control) that caused by the control pressure force of the control piston 138 (the force, for example, A _a · P _Control) corresponds in its longitudinal direction of motion a greater closing pressure p _connected to the output side effective area 142 (e.g., a ratio a _a / a _of the input-side effective area 140 to the output side effective area 142 larger closing pressure).

The pressure piston chamber 112 can be filled with hydraulic fluid during the transition from the first state to the second state of the coupling mechanism 110 via the non-return valve 132 also connected to the control line 146 on the input side. A control pressure p _control in the control line 146 is sufficient to _closing maintain = p _tax · A _a / _A in the plunger chamber 112 to the rigid coupling of the Abgriffselements 106 by means of the control piston 138 a greater ratio of the active surfaces 140 and 142 closing pressure p.

Without pressurization of the control piston chamber 136 via the control line 146, the control piston 138 assumes an open position. In the open position, the output side fluid connection 144 between control unit 130 and plunger chamber 112 is in fluid communication with a relief line 148 for transitioning from the second state to the first state of the coupling mechanism 110.

At the in FIG. 5 shown embodiment of the control unit 130, the check valve 132 and the control piston 138 are on the input side and the output side in fluid communication, ie check valve 132 and the control piston 138 in the control piston chamber 136 are connected in parallel. The input side of the control unit 130 is in fluid communication with the control line 146. The output side of the control unit 130 is connected to the pressure piston space 112 via a single fluid connection 144. In a variant of the control unit 130, which can be used in each embodiment, the check valve 132 and the control piston 138 are connected on the output side via separate fluid connections with the pressure piston chamber 112.

The control line 146 is preferably connected via a solenoid valve for controlling the first and second states of the coupling mechanism 110 with an existing lubricating oil supply of the internal combustion engine.

FIG. 6 shows a perspective view of a third embodiment of the valve drive lever 100th Im in FIG. 6 In the third embodiment shown, the control unit 130 is arranged on the coupling mechanism 110. The control unit 130 is preferably arranged on the side of the tapping element 106 facing away from the cam 108 in the longitudinal movement direction (ie, the transverse direction to the lever arm 102). In particular, the longitudinal movement direction of the tapping element 106 and the longitudinal movement direction of the control piston 138 may be coaxial and / or the fluid connections between the control piston 138 and the pressure piston chamber 112 may be realized through a bore within a common housing of the coupling mechanism 110 and the control unit 130.

The pivot axis 104 is pivotally mounted via a bolted to the cylinder head of the engine bearing block 152. The control line 146 is guided through bores within the lever arm 102 and is in fluid communication with the solenoid valve for controlling the first and second states of the coupling mechanism 110 via the pivot axis 104 irrespective of the pivotal position of the lever arm 102.

In an in FIG. 6 shown first variant, the lever arm 102 between pivot axis 104 and actuator 120 comprises a double web 154. Between the webs 154 space for connections of an injection nozzle 156 of the internal combustion engine is free. In a second variant, which can be realized in each embodiment, the lever arm 102 is guided over the injection nozzle 156.

FIG. 7 schematically shows a cross section of the third embodiment of the valve drive lever 100 in the pivot plane of the pivot axis 104. The rocker arm 102 is supplied via a bore of a permanent oil pressure line 158 constantly oil from the engine oil circuit. When the engine is operating, oil pressure is always applied to the permanent oil pressure line 158 to lubricate a roller tappet 160 of the tappet 106 as it moves up and down on the cam 108. The realized through holes in the rocker arm 102 control line 146 is also supplied with the oil from the engine circuit, preferably via a previously switched solenoid valve which selectively supplies oil via the pivot axis 104 for controlling the first and second state of the coupling mechanism 110th

The first and second state of the coupling mechanism 110 may also be referred to as the off state with respect to the function of the compressed gas removal valve 122 (eg, compressed air). In the on state, therefore, oil pressure is present in the bore of the control line 146. By the oil pressure, a ball is pressed as a closing element 134 from the check valve 132 formed by a reduction and allows the oil to flow via a short bore as a fluid connection 144-1 in the pressure piston chamber 112. At the same time, the oil flows into the control piston chamber 136 and presses the control piston 138-1 (which defines the input-side active surface) to a ball as a closing element 138-2 with the output-side active surface. The closing element 138-2 closes the fluid connection 144-2 between the pressure piston chamber 112 and the relief line 148. Thus, the pressure piston chamber 112 is a closed space and a pressure piston 162 of the tapping element 106 is pushed away from the lever arm 102 toward the cam 108. The pressure piston 162 is always on the roller tappet 160.

The anti-rotation device 116 formed by a protruding screw shank comprises a projection which engages in a longitudinal groove on the pressure piston 162. Optionally, the projection also serves as a stop, wherein the upper end of the groove forms the shoulder 114.

Thus, the roller tappet 160 is in rigid coupling with the lever arm 102 on the cam 108, and the entire rocker arm 102 is moved due to the rigid coupling by the cam 108 for actuation 128 of the valve 122nd

At the same time, preferably by fluid communication with the control line 146, also oil pressure in a controlled oil pressure line 164 is present for supplying the actuating element 120 with lubricating oil. The actuator 120 includes a ball-and-socket joint 166 and an actuating surface 168, each of which wets with lubricating oil via the controlled oil pressure line 164 become. In the controlled oil pressure line 164 only oil is conveyed when the coupling mechanism 110 in the second state, so the rocker arm 102 in the on state, with open solenoid valve.

In the first state (i.e., off), the oil supply to the control line 146 (and the controlled oil pressure line 164 in fluid communication therewith) is interrupted via the solenoid valve. Thus, no pressure is present on the control piston 138-1 and the fluid connection 144-2 formed as a relief bore is not closed any further via the control piston 138-1 and its closing element 138-2 on the output-side effective surface 142. The open position of the closure member 138-2 brings the fluidic connection 144-2 into communication with the relief conduit 148. The roller lifter 160 is urged to the lever arm 102 due to actuation by the cam 108 together with the pressure piston 162. The plunger 162 pushes the oil out of the plunger chamber 112 via the fluid connection 144-2 in the discharge line 148 to the outside. Since now no pressure is applied in the pressure piston chamber 112 and no longer acts on the tapping element 106 via the pressure piston 162, the roller tappet 160 of the tapping element 106 is only pressed by the compression spring 118 onto the cam 108 in accordance with the spring-elastic first state of the coupling mechanism 110. That is, the roller tappet 160 and the pressure piston 162 of the tapping member 106 move up and down, but not the entire valve train lever 100, for example, because the spring force of the compression spring 118 is less than the pressing force of a valve spring of the valve 122 on the opposite side of the Lever arm 102 cooperates with the actuating element 120.

The actuator may further include an adjustment screw 170. Alternatively or additionally, a valve clearance of the valve 122 can be adjusted by the fluid volume in the pressure piston chamber 112 in the second state.

FIG. 8 shows an enlarged section of the cross section of FIG. 7 , Between the pivot axis 104 and a bore in the lever arm 102, a bearing bush 172 is arranged. In each exemplary embodiment, oil (for example during operation of the internal combustion engine permanently) can be supplied into the control line 146 via the bearing bush 172 into the oil pressure line 158 and / or (for example for controlling the state of the coupling mechanism 110). In each pivotal position of the lever arm 102 connect azimuthal slots in the bearing bush 172 on the lateral surface of the pivot axis 104 ends of the holes in the pivot axis 104 with the corresponding ends of the holes in the lever arm 102. Im in FIG. 8 shown third embodiment are the control line 146 and the controlled oil pressure line 164 via bores in the pivot axis 104 in fluid communication, so that the actuator 120 is supplied with lubricating oil if and only if the coupling mechanism 110 is in the rigid second state.

FIG. 9 shows a schematic cross section in the pivot plane of a fourth embodiment of the valve train lever 100. The fourth embodiment differs from the preceding embodiments in the configuration of the coupling mechanism 110. The coupling mechanism 110 of the fourth embodiment is used in connection with each embodiment above. Features that are the same as those of the above embodiments or that can be exchanged are shown in FIG FIG. 9 provided with the same reference numerals.

The compression spring 118 is supported on the lever arm 102 and, instead of on the pressure piston 162 of the tapping element 106, rests against the roller tappet 160 of the tapping element 106. An additional counter-pressure spring 174 constantly pushes the pressure piston 162 upwards in the first state of the coupling mechanism 110, that is to say in the switch-off mode of the valve drive lever 100 (that is, toward the lever arm 102). The pressure piston 162 no longer moves up and down in the first state and thus does not cause unintentional pumping of the oil.

Im in FIG. 9 shown fourth embodiment, the counter-pressure spring 174 is supported on the pressure piston 162 and is located on the roller tappet 160 at. In an alternative embodiment of the coupling mechanism, the lever arm 102 and the pressure piston 162 are connected to a tension spring. As a result, in the first state, the pressure piston 162 does not rest on the roller tappet 160 and is pressed to the lever arm 102 (ie to a minimum volume of the pressure piston chamber 112). The spring tension of the counterpressure spring 174 of the pressure piston 162 is (at each position of the pressure piston 162 and the roller tappet 160) at most so large that at in the control line 146 and thus in the pressure piston chamber 112 fitting pressure (for example, at 1 bar oil pressure) of the pressure piston 162 to the roller tappet 160 is pressed down and abuts this for rigid coupling in the second state of the coupling mechanism 110th

In all embodiments, the compression spring 118 ensures that the roller tappet 160 rests on the cam 108 in both the first and in the second state. The spring tension of the compression spring 118 for the roller tappet 160 is at least so great that the mass of the roller tappet 160 follows the cam 108 at the maximum speed. As a result, the efficiency is improved, and wear and noise are reduced.

The coupling mechanism 110 of the fourth embodiment has the advantage that the pressure piston 162 in the first state of the coupling mechanism 110 (i.e., in the off mode of the valve train lever 100) does not constantly follow the up and down movement of the roller tappet 160 and unnecessarily pumps oil. As a result, the efficiency is improved.

FIG. 10 shows a perspective view of the fifth embodiment of the Ventiltriebhebels 100. The fifth embodiment differs from the preceding embodiments in the arrangement of the control unit 130. The arrangement of the control unit 130 of the fifth embodiment is implemented accordingly in each embodiment above. Features that are the same as those of the above embodiments or that can be exchanged are shown in FIG FIG. 10 provided with the same reference numerals.

In the fifth embodiment, the control unit 130 is not arranged in the extended axis above the pressure piston 162, but at another (basically any point, for example, the lever arm 102). The control unit 130 and the coupling mechanism 110 may (for example, as in the second embodiment of the FIG. 5 ) via a fluid connection 144 or (for example, as in the fifth embodiment of the FIG. 10 ) via two fluid connections 144-1 and 144-2.

An advantageous location on lever arm 102 for placement of control unit 130 is at pivot axis 104 (eg, above pivot axis 104). The fifth embodiment of FIG. 10 shows an example of this arrangement. The arrangement at the pivot axis 104 results in a lower overall height. Further, the inertia (ie, the moment of inertia of the valve train lever 100 with respect to the pivot axis 102) is improved. While in the FIG. 10 5, the orientation of the control unit 130 with respect to the direction of movement of the control piston 138 perpendicular to the lever arm 102, parallel to the direction of movement of the valve lifter 124 and / or parallel to the transverse direction of the lever arm, the control unit 130 may also be parallel to the lever arm 102, perpendicular to the direction of movement of the valve lifter 124 or be arranged obliquely thereto. The basic operating principle does not change, only the oil bores are adapted to the location and / or orientation of the control unit 130.

Although the invention has been described in terms of exemplary embodiments, it will be apparent to those skilled in the art that various changes may be made and equivalents may be substituted for. Furthermore, many modifications can be made to a particular situation or a particular situation Drive to adapt to the teachings of the invention. Thus, the invention is not limited to the disclosed embodiments and implementations, but includes all embodiments falling within the scope of the appended claims.

LIST OF REFERENCE NUMBERS

100

Valve gear lever

102

lever arm

104

swivel axis

106

tapping element

108

cam

110

coupling mechanism

112

Pressure piston chamber

114

paragraph

116

Anti-rotation lock, optional stop

118

compression spring

120

jig

122

Valve in the cylinder head

124

tappet

126

pivotal movement

128

actuating movement

130

control unit

132

check valve

134

closing element

136

Control piston chamber

138

spool

140

Input side effective area

142

Output side effective area

144

Fluid connection between control unit and coupling mechanism

146

control line

148

relief line

152

bearing block

154

double bridge

156

injection

158

Permanent oil pressure line

160

roller plunger

162

pressure piston

164

Controlled oil pressure line

166

Ball head connection

168

actuating surface

170

adjustment

172

bearing bush

174

Contrast spring

Claims (15)

Valve drive lever (100) for actuating a valve (122) of a reciprocating piston engine, in particular an internal combustion engine, comprising: a lever arm (102) pivotable about an axis (104); a tapping element (106) abutting or engageable with a cam (108) of a camshaft of the reciprocating engine; a coupling mechanism (110) via which the tapping element (106) is resiliently coupled to the lever arm (102) in a first state and rigidly in a second state; and a with the lever arm (102) connected to a valve stem (124) of the valve (122) fitting or engageable actuator (120). Valve gear lever according to claim 1, wherein the tapping element (106) is arranged in a transverse direction transversely to the lever arm (102) and / or arranged immovable in a longitudinal direction transverse to the transverse direction. Valve gear lever according to claim 2, wherein the coupling mechanism (110) comprises a pressure piston chamber (112) and a movable in the transverse direction, the pressure piston chamber (112) limiting the pressure piston (162). Valve gear lever according to claim 3, wherein the pressure piston (162) at least in the second state cooperates with the Abgriffselement (106) and the pressure piston chamber (112) is filled in the second state with a hydraulic fluid. A valve train lever according to any one of claims 2 to 4, wherein the coupling mechanism (110) comprises a compression spring (118) supported on the lever arm (102) biasing the pick-off element (106) in the transverse direction. Valve gear lever according to claim 5 in conjunction with claim 3, wherein the pressure piston (162) in the first and second state cooperates with the Abgriffselement (106), and the compression spring (118) in the pressure piston chamber (112) is arranged and on the pressure piston (162). Valve gear lever according to claim 5, wherein the compression spring (118) rests on the tapping element (106). A valvetrain lever according to claim 7 when appended to claim 3, wherein the coupling mechanism (110) includes a counterpressure spring (174) supported on the tapping member (106) biasing the plunger (162) in the transverse direction and the tapping member (106) in the first state of Plunger (162) is spaced in the transverse direction. A valve train lever according to any one of claims 1 to 8, wherein the tapping member (106) comprises a roller tappet (160). Valve gear lever according to one of claims 1 to 9 in conjunction with claim 3, further comprising a control unit (130) which is on the output side with the pressure piston chamber (112) in fluid communication (144). Valve gear lever according to claim 10, wherein the control unit (130) on the input side via a solenoid valve selectively with the oil circuit of the reciprocating engine in fluid communication (146). Valve gear lever according to claim 10 or 11, wherein the control unit (130) on the coupling mechanism (110) or on a pivot bearing of the pivotable lever arm (102) is arranged. Valve gear lever according to one of claims 10 to 12, wherein the control unit (130) comprises a control piston (138) having an input-side active surface (140) and an output-side active surface (142) which is smaller than the input-side active surface (140). Reciprocating piston engine, in particular internal combustion engine, with a valve drive lever (100) according to one of claims 1 to 13. Motor vehicle, in particular commercial vehicle, with an internal combustion engine according to claim 14.

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