DE102020113222A1 - Rocker arm arrangement for a valve train of an internal combustion engine - Google Patents

Abstract

The invention relates to a rocker arm arrangement for a valve drive of an internal combustion engine, with at least one rocker arm (1) mounted on a rocker arm axis (3) with a valve-side lever (1a) for actuating at least one gas exchange valve (4, 5) of the internal combustion engine and with two actuation-side levers (1b, 1c) is arranged pivotably for the pivotable drive, the levers (1a, 1b, 1c) being mounted on the rocker arm axis (3) so as to be pivotable relative to one another and a first lever (1b) on the actuation side by first coupling means ( 9) for transmitting a first lifting movement for valve actuation and a second actuation-side lever (1c) can be coupled to the valve-side lever (1a) by second coupling means (10) for transmitting a second lifting movement for valve actuation.

Description

Field of invention

The invention relates to a rocker arm arrangement for a valve drive of an internal combustion engine according to the type defined in more detail in the preamble of claim 1.

the end DE 10 2017 129 720 A1 a switchable rocker arm arrangement with a rocker arm is known which is mounted on a machine-fixed rocker arm axis and has a cam arm connected to a camshaft and a valve arm connected to at least one gas exchange valve of a reciprocating internal combustion engine.

Summary of the invention

The invention is therefore based on the object of proposing a rocker arm arrangement of the aforementioned type which enables a simply constructed variable valve control which is improved in operation.

The object is achieved by the features of claim 1. Further advantageous configurations emerge from the respective subclaims, the description and the drawings.

A rocker arm arrangement for a valve drive of an internal combustion engine with at least one rocker arm is proposed. The rocker arm is pivotably arranged on a rocker arm axis with a valve-side lever for actuating at least one gas exchange valve of the internal combustion engine and with two actuation-side levers for pivoting drive, the levers being mounted on the rocker arm axis such that they can pivot with respect to one another. To switch the rocker arm, a first actuation-side lever can be coupled to the valve-side lever by first coupling means for transmitting a first lifting movement for valve actuation and a second actuation-side lever by second coupling means for transmitting a second lifting movement for valve actuation. In this way, the valve-side lever can each be selectively switched by the actuation-side lever. A simply structured, multiple variable operation, in particular a combination of valve lift switchover and valve lift switchover, with at least one switchable rocker arm is made possible. Here, the valve lift can be switched off completely or an additional valve lift can be switched on to a full valve lift or the latter can be deactivated. Another advantage is that the valve lift height of the additional valve lift is less than the valve lift height of the full valve lift and, in particular, can be set directly below this. This enables a so-called Miller hub to be implemented.

In a particularly advantageous manner, four different and mutually independent lift cams can be transmitted by the rocker arm. The lever on the valve side can be decoupled from the two levers on the actuation side, as a result of which valve lift shutdown can be implemented in a base circle curve. The valve-side lever can be coupled to a first actuation-side lever, while it can be decoupled from the second actuation-side lever. As a result, in a second lift curve, the transmission of only one full valve lift picked up by a primary cam, for example, can be transmitted. The lever on the valve side can be coupled to both levers on the actuation side at the same time, so that a combination of full valve lift and additional valve lift can be transmitted in a third lift curve. This is particularly advantageous in the case of what is known as internal exhaust gas recirculation in the internal combustion engine. In a fourth lift curve, the valve-side lever can be coupled to the second actuation-side lever, while it can be decoupled from the first actuation lever. As a result, the transmission of only one additional valve lift, for example picked up by a secondary cam, can be transmitted. This would be the case, for example, for the above-mentioned Miller stroke on the intake valve side or for an engine brake and / or for the implementation of so-called engine thermal management on the exhaust valve side to reduce the thermal stress and wear on the components.

In a further advantageous embodiment of the invention, a second switchable rocker arm is provided in addition to the first switchable rocker arm. The latter is pivotably arranged on the rocker arm axis with a second valve-side lever for actuating at least one gas exchange valve of the internal combustion engine and with a third pivotably drivable actuation-side lever, the levers being mounted on the rocker arm axis such that they can pivot with respect to one another. To switch the second rocker arm, the third lever on the actuation side can be coupled to the second lever on the valve side by third coupling means for transmitting a third stroke movement for valve actuation. In this way, the second rocker arm can be switched independently of the first rocker arm and vice versa.

It is also advantageously possible to control at least one outlet gas exchange valve through the first switchable rocker arm and at least one inlet gas exchange valve for a cylinder of the internal combustion engine independently of one another through the second switchable rocker arm. This can be achieved in a simple manner in that the first valve-side lever is in valve contact with at least one outlet gas exchange valve of the internal combustion engine and the second valve-side lever is in valve contact with at least one inlet gas exchange valve.

In a further particularly advantageous embodiment of the invention, the first lever on the actuation side and the third lever on the actuation side are each in contact with a first cam of a camshaft of the internal combustion engine for tapping a full valve lift for valve actuation. As a result, the transmission of a full valve stroke or a shutdown or a jointly effected cylinder shutdown is possible on the first and second rocker arms independently of one another. Since the second actuation-side lever for tapping an additional valve lift is in contact with a second cam of the camshaft, it is possible to transmit an additional valve lift on the first rocker arm alone without a full valve lift or to transmit an additional valve lift together with the transmission of a full valve lift during one camshaft revolution. This arrangement also enables rolling or alternating cylinder deactivation and, at the same time, an engine brake that is graduated or that can be implemented selectively independently of one another for each cylinder. The levers on the actuation side each allow the lifting movement to be picked up directly by the respective cam of the camshaft, so that further transmission means can be avoided. Frictional losses during tapping can be minimized by using a cam roller.

The embodiment can be further simplified if each of the coupling means is assigned an actuator for switching and each rocker arm can be switched individually by a separate actuator. As a result, the actuators can be made smaller and can be produced in larger numbers with lower production costs.

It is advantageous if the actuators are designed as electrical lifting magnets, each of which has a linearly displaceable armature through which the respective coupling means for switching can be displaced in direct actuating contact. Additional components for transmitting the actuating movement are thus avoided. The actuator stroke is reduced and the switching time shortened. In addition, the direct individual actuation of the respective rocker arm increases the switching performance and at the same time reduces the variances in the switching times. The component tolerance influences and the manufacturing costs can be minimized.

The actuators can be at least partially integrated into a carrier connected to the rocker arm axis and arranged at a radial distance from the rocker arm axis. The actuators can thus be arranged on the carrier in a particularly simple manner at any individual radial distance from the rocker arm axis. This enables the actuators to be arranged and the coupling means to be switched close to the rocker arm axis, so that the relative movement of coupling means integrated in the valve-side lever or in an actuation-side lever, for example, compared to the actuators, is low during operation. A permanent contact for switching can thus be easily established between the actuator and the coupling means. In addition, the rocker arm arrangement with the actuators, the rocker arm axis and the rocker arms can be easily attached as a preassembled structural unit via the carrier on the cylinder head of the internal combustion engine, in particular by means of a screw connection.

In a further advantageous embodiment of the invention, the coupling means are integrated into the rocker arm and are arranged displaceably for switching in respectively assigned axial bores on the valve-side levers and on the respectively assigned actuation-side levers. In this way, an axial coupling of the respectively assigned valve-side and actuation-side levers transversely to the longitudinal axis of the levers and thus a so-called transverse locking of the switchable rocker arms is made possible. A space-saving arrangement of the coupling means near the rocker arm axis can be achieved through the transverse locking

The first and third coupling means can each have an actuating piston displaceable in an axial through hole on the respective first and third valve-side lever, by means of which a coupling piston arranged in an axial bore on the respective first and third actuation-side lever can be displaced for switching in direct actuating contact. Here, the latter can be displaced into the through-hole of the lever for coupling with the respective first and third valve-side lever.

It is also advantageous if the coupling means that are slidably integrated in a valve-side lever or in an actuation-side lever for switching and at least one actuator assigned to them for switching are arranged in such a way that when the respective valve-side lever or the respective actuation-side lever is pivoted relative to the respective actuator an at least partial overlap in the displacement direction between the coupling means and the actuator for switching is guaranteed. In this way, the coupling means for switching can be permanently controlled by the actuator. The coupling means can be in permanent contact on the actuator side when overlapping or they can be arranged at a distance from one another by a slight air gap.

Advantageously, it is also possible to displaceably dispose coupling means integrated into a lever on the actuation side for switching and at least one actuator integrated in the carrier associated with the latter for actuation in such a way that when the lever on the actuation side or the lever on the valve side swings relative to one another with respect to the carrier, the coupling means can be applied to the carrier in the decoupled state on the actuator side in the displacement direction. The coupling means can thus be permanently applied to the carrier in the decoupled state in sliding pivot contact. In this way, a simple permanent safeguard against falling out of the coupling means from the lever on the actuation side or from the lever on the valve side can be achieved. Coupling means that are slidably integrated into a valve-side lever for switching can be secured against falling out in the decoupled state in an analogous manner.

Return spring means can be provided which each preload at least one actuation-side lever and at least one associated valve-side lever in the pivoting direction against one another into a non-pivoted basic position. In this case, axially aligned opposing recesses are provided on the respective actuation-side lever and on the respective valve-side lever on the axially opposite lever longitudinal sides, in which the return spring means are at least partially arranged and braced in the pivoting direction. The return spring means can thus be arranged integrated in one or both rocker arms in a particularly space-saving manner.

In a further particularly advantageous embodiment of the invention it is provided that the first and third coupling means for coupling the first and second valve-side levers to the first and third actuation-side levers are each biased into the coupled state by spring means. The second coupling means for coupling the first valve-side lever to the second actuation-side lever are biased into the decoupled state by spring means. In the unactuated state of the coupling means, the first and the second valve-side lever can easily be retained by the first and third coupling means in the coupled state with the first and third actuation lever, respectively, while the first valve-side lever is decoupled from the second actuation-side lever. As a result, a full valve lift can be transmitted, for example, by the first and the second rocker arm, while the additional valve lift is deactivated.

The first and second rocker arms can be switched and actuated independently of one another. For example, it is possible to operate at least one outlet gas exchange valve of the internal combustion engine through the first rocker arm and at least one inlet gas exchange valve through the second rocker arm. Conversely, it is also conceivable to actuate at least one inlet gas exchange valve through the first rocker arm and at least one outlet gas exchange valve through the second rocker arm.

The integration of the actuators in a common carrier, which is connected to the common rocker arm axis, on which the switchable rocker arms with the valve-side and actuation-side levers are arranged, enables the rocker arm arrangement to be designed as a preassembled unit that can be easily attached to the cylinder head of the internal combustion engine via the carrier is. A screw connection can be provided in each case for fastening the rocker arm shaft to the carrier and for fastening the carrier to the cylinder head. The switchable rocker arm arrangement can be attached directly to the cylinder head individually for each cylinder. It is also possible to arrange several rocker arms on a common rocker arm axis for the entire number of cylinders. Accordingly, it can then also be selected whether only individual cylinders are provided with the switchable rocker arm unit. For example, only half of the existing cylinders of the internal combustion engine can be equipped with the rocker arm arrangement for cylinder deactivation. However, it is also conceivable to equip all cylinders accordingly if an overrun cut-off or what is known as coasting operation of the engine is to be implemented.

Figure list

• 1 bis 3 jeweils eine perspektivische Ansicht einer erfindungsgemäßen Kipphebelanordnung in verschiedenen Betriebszuständen,
• 4 eine in einer ersten Schnittebene geschnittene Ansicht der Kipphebelanordnung in einem ersten Schaltzustand,
• 5 eine in einer zweiten Schnittebene geschnittene Ansicht der Kipphebelanordnung im ersten Schaltzustand,
• 6 eine in der ersten Schnittebene geschnittene Ansicht der Kipphebelanordnung in einem zweiten Schaltzustand,
• 7 eine in der zweiten Schnittebene geschnittene Ansicht der Kipphebelanordnung in einem dritten Schaltzustand,
• 8 eine in einer dritten Schnittebene geschnittene Ansicht der Kipphebelanordnung.

Further features of the invention emerge from the following description and from the drawings, in which an exemplary embodiment of the invention is shown in a simplified manner. Show it:

• 1 until 3 each a perspective view of a rocker arm arrangement according to the invention in different operating states,
• 4th a view of the rocker arm arrangement in a first switching state, cut in a first sectional plane,
• 5 a view of the rocker arm arrangement in the first switching state, cut in a second sectional plane,
• 6th a view of the rocker arm arrangement in a second switching state, cut in the first sectional plane,
• 7th a view of the rocker arm arrangement in a third switching state, cut in the second sectional plane,
• 8th a sectional view of the rocker arm arrangement in a third sectional plane.

Detailed description of the drawings

In the 1 until 3 The rocker arm arrangement according to the invention shown has a first and a second rocker arm 1 , 2 on, which on a common stationary or machine-fixed rocker arm axis 3 are arranged. The first rocker arm 1 consists of a first lever on the valve side 1a to operate two outlet gas exchange valves 4th , 5 the internal combustion engine and two levers on the actuation side 1b , 1c to the pivotable drive. The second rocker arm 2 comprises a second valve-side lever 2a to operate two inlet gas exchange valves 6th , 7th the internal combustion engine and a third pivotably drivable actuation-side lever 2 B . The valve-side and actuation-side levers 1a , 1b , 1c , 2a , 2 B are each pivotable to one another on the rocker arm axis 3 arranged. The pivotable drive of the lever on the actuation side 1b , 1c , 2 B takes place via an overhead camshaft 8th .

For switching the first rocker arm 1 are the first lever 1b via first coupling agent 9 and the second operating side lever 1c via second coupling agent 10 with the first lever on the valve side 1a connectable. In this way, the first rocker arm is designed as a switchable triple rocker arm. For switching the second rocker arm 2 is the second lever on the valve side 2a through third coupling agent 11th with the third lever on the actuation side 2 B connectable. Here are the coupling agents 9 , 10 , 11th each by an assigned separate electrical actuator 12th , 13th , 14th selectively switchable.

The levers on the actuation side 1b , 1c, 2a are each at one end with a cam roller for the pivotable drive 15th , 16 , 17th in direct contact with an associated cam 18th , 19th , 20th the camshaft 8th for picking up a cam stroke movement. The valve-side levers 1a , 2a are used to transfer the levers on the actuation side 1b , 1c , 2 B tapped cam lift movement as valve lift movement on the respective gas exchange valves 4th , 5 respectively. 6th , 7th the internal combustion engine. The levers on the valve side are available for this purpose 1a , 2a at one end of the lever on the valve side in contact with two outlet gas exchange valves 4th , 5 or with two inlet gas exchange valves each 6th , 7th of a cylinder of the internal combustion engine. Via a fork-shaped valve contact 21 , 22nd , a so-called valve bridge, on the valve-side lever end area of the respective axially inner valve-side lever 1a , 2a can each have two gas exchange valves 4th , 5 respectively. 6th , 7th , ie 4 gas exchange valves per cylinder, can be operated at the same time. Alternatively, only one gas exchange valve, that is to say two gas exchange valves per cylinder, can be actuated in each case, a valve bridge not being required in each case. In the 1 and 2 Rocker arm arrangement shown with two switchable rocker arms 1 , 2 is used for variable valve control on an engine, not shown, for a truck that has a single rocker arm 1 , 2 driving overhead camshaft 8th is shown.

The valve-side levers 1a , 2a are each designed as two-sided levers, the pivot points of which are each on the rocker arm axis 3 each in one between the respective valve-side lever end area with the valve contact 21 , 22nd and a coupling-side lever end area 23 , 24 located central area, so that the valve-side lever end areas on the one hand and the coupling-side lever end areas 23 , 24 around the rocker arm axis 3 are pivotable. At the coupling-side lever end area 23 respectively. 24 are the valve-side levers 1a respectively. 2a with the levers on the actuation side 1b , 1c , respectively. 2a can be coupled to transmit a valve stroke movement. This allows the coupling agent 9 , 10 , 11th and the assigned actuators 12th , 13th , 14th on the camshaft side of the rocker arm axis 3 between this and the camshaft 8th to be ordered.

The levers on the actuation side 1b , 1c , respectively. 2a are parallel to the levers on the valve side 1a , 2a arranged and each with a support-side end on the common rocker arm axis 3 pivoted. The first operating lever 1b flanks the first lever on the valve side 1a at its from the second rocker arm 2 facing away from the axial outer longitudinal side of the lever, while the second operating lever 1c at the second rocker arm 2 facing axially inner lever longitudinal side is positioned. The third operating lever 2 B is at that of the first rocker arm 1 facing away from the axially outer longitudinal side of the lever of the second valve-side lever 2a arranged.

The levers on the actuation side 1b , 1c , 2a each grip with the cam rollers 15th , 16 , 17th a cam lift movement for valve actuation from the respective cam 18th , 19th , 20th the camshaft 8th away. The cam rollers 15th , 16 , 17th are each at the end of the actuation-side lever facing away from the support-side end 1a , 2a arranged. The first lever on the actuation side 1b engages with the cam roller 15th a first lifting movement as a full valve lift from the first cam 18th as the primary cam, while the second lever on the actuation side 1c with the cam roller 16 a second stroke movement as an additional valve stroke from a second cam 19th taps as a secondary cam. Through the third lever on the actuation side 2 B is with the cam roller 17th a third lifting movement as a full valve lift from the third cam 20th the camshaft 12th tapped. This is through the first lever on the valve side 1 a full valve lift and / or an additional valve lift on the outlet gas exchange valves 4th , 5 transferable. Through the second lever on the valve side 2a is a full valve lift on the inlet gas exchange valves 6th , 7th transferable.

In 1 is the rocker arm arrangement in a first operating state in the base circle phase of the cam 18th , 19th , 20th while in 2 in a second operating state of the outlet Primary cam 18th in the cam lift phase and the exhaust secondary cam 19th as well as the inlet cam 20th are each in the base circle phase. In a third operating state according to 3 is the inlet cam 20th in the cam lift phase. Here are the exhaust primary cams 18th and the exhaust secondary cam 19th in the base circle phase. The respective lever on the actuation side is activated in the cam lift phase 1b , 1c , 2 B actuated by tapping a cam stroke while it is not actuated in the base circle phase.

The coupling agent 9 , 10 , 11th are each in the associated valve-side lever 1a , 2a and lever on the actuation side 1b , 1c , 2 B Integrated to save space. 4th and 6th show the rocker arm arrangement in a section with one through the first and third coupling means 9 , 11th and by the assigned actuators 12th , 14th running first cutting plane. The first and third coupling agents 9 , 11th each have a cylindrical actuating piston 9a , 11a and a cylindrical coupling piston 9b , 11b on. The actuating piston 9a , 11a are each in an axial through hole 25th respectively. 26th at the coupling-side lever end area 23 respectively. 24 of the first and the second valve-side lever 1a , 2a arranged to be slidable for switching. On the first and third lever on the actuation side 1b respectively. 2 B is each in an axial bore 27 respectively. 28 the respective coupling piston 9b respectively. 11b slidably added.

The actuating piston 9a respectively. 11a are each in direct control contact through the respective actuator on the face side at an actuator-side end 12th , 14th axially displaceable. They are each with the other end in contact with the respective coupling piston 9b , 11b . The latter are made by spring means 29 , 30th against the respective actuating piston 9a , 11a biased. The spring means 29 , 30th are each as a helical compression spring in the bore 27 , 28 arranged coaxially. The movement of the actuating piston 9a , 11a is through one in each of the through holes 25th , 26th socket pressed into the end of the actuator 31 , 32 and in each case by a stop formed axially on the end face of this 31a , 32a limited on the actuator side.

In 5 and 7th is the rocker arm arrangement in a section with one through the second coupling means 10 and the assigned actuator 13th extending second sectional plane shown. The second coupling agent 10 are by a cylindrical coupling piston 10a educated ( 3 ), which is in an axial through hole 33 of the second operating-side lever 1c is arranged displaceably for switching. The coupling piston 10a is in direct control contact through the actuator at one end on the actuator side 13th axially displaceable. It is for coupling in an axial bore 34 on the first lever on the valve side 1a movable. The hole 34 is designed here as an axial through hole. The coupling piston 10a is by spring means 35 against the actuator 13th biased. The spring means 35 are in the bore as a helical compression spring 34 arranged coaxially.

The coupling pistons are used for coupling 9b , 10b, 11b respectively, as in 4th and 7th shown, in the non-pivoted basic position of the respective valve-side and actuation-side lever 1a and 1b , 1a and 1c , respectively. 2a and 2 B in the respective base circle phase of the cam 18th , 19th , 20th ( 1 ) with a coupling-sided end from the coupling-sided end of the bore 27 , 28 on the respective lever on the valve side 1a respectively. 2a or the through hole 33 on the second lever on the actuation side 1c out into the respective through hole 25th , 26th on the respective lever on the actuation side 1b , 2 B or into the hole 34 of the first lever on the valve side 1a movable. Here are the coupling pistons 9b , 10b, 11b by the spring force of the respective pretensioned spring means 29 , 30th or against the spring force of the spring means 35 slidable into the coupled position. At the same time, the spring means 35 pre-tensioned for decoupling. The decoupling after 5 and 6th takes place by actuating the respective actuator 12th , 13th , 14th and displacement of the respective actuating piston 9a , 10a , 11a in contact with the respective coupling piston 9b , 10b, 11b against the spring force of the respective spring means 29 , 30th or by the spring force of the pretensioned spring means 35 . The coupling pistons are thereby 9b , 10b, 11b in the respective hole 27 , 28 or in the through hole 33 pushed back and at the same time the spring means 29 , 30th pre-tensioned for coupling.

The actuators 12th , 13th , 14th are each designed as electrical lifting or linear magnets ( 1 until 3 ). They are in an axially between the rocker arms 1 , 2 arranged common carrier 36 recorded with a base plate 36a via a first screw connection 37 with the rocker arm axis 3 connected is. The carrier 36 has two from the base plate 36a outgoing perpendicular to the rocker arm axis 3 protruding arms 36b 36c on that parallel to the rocker arms 1 , 2 are arranged and in the direction of the rocker arm axis 3 camshaft arranged in parallel 8th extend. The poor 36b , 36c form cylindrical sockets 38 , 39 , 40 into which the actuators 12th , 13th , 14th each with an electromagnetically linearly displaceable armature 12a , 13a , 14a are arranged ( 4th until 7th ). On the arms 36b 36c the actuators can 12th , 13th , 14th each in the sockets 26th , 27 , 28 at any radial distance from the rocker arm axis 3 and at the same time on the camshaft side of the rocker arm axis 3 between this and the camshaft 8th to be ordered.

By energizing the lifting magnets, the respective armature is 12a , 13a , 14a with a coupling-side end in direct contact with the respective coupling agent 9 , 10 , 11th to switch from the respective socket 38 , 39 , 40 can be pushed out. By switching off the current supply, the actuators are 12th , 13th , 14th can be deactivated and the respective anchor 12a , 13a , 14a into the respective socket 38 , 39 , 40 can be moved back. To reset the anchor 12a , 13a , 14a in the de-energized state, return spring means can, as shown, in the respective lifting magnets 12b , 13b , 14b be arranged. The carrier 36 forms on a first arm 36b a first and a second socket 38 , 39 . The arm 36b with the sockets 38 , 39 is on the first lever on the valve side 1a facing away from the axial inside of the second actuation-side lever 1c arranged. The sockets are located here 38 , 39 the axially inner side of the second lever on the actuation side 1c opposite to. In the sockets 38 , 39 is the first and the second actuator 12th , 13th with the respective anchor 12a , 13a for direct contact with the respective actuating piston 9a respectively. 10a the first and the second coupling means 9 , 10a arranged. The second arm 36c is with a third socket 40 formed and on the axial inside of the second valve-side lever 2a led along. The socket is located here 40 the axially inside of the second valve-side lever 2a opposite to. On the second arm 36c is in the third socket 40 the third actor 14th with the anchor 14a for direct contact with the actuating piston 11a the first and the third coupling means 11th arranged.

In an in 4th and 5 The actuators are located in the first switching state of the rocker arm arrangement shown 12th , 13th , 14th in the deactivated state, ie all three lifting magnets are not energized and the armature 12a , 13a , 14a are in the respective sockets 38 , 39 , 40 pushed back. The first lever is on the valve side 1a through the first coupling agent 9 with the first lever on the actuation side 1b coupled ( 4th ) and at the same time through the second coupling means 10 from the second lever on the actuation side 1c decoupled ( 5 ). The latter is therefore in the idle stroke, since that of the second cam 19th tapped additional valve lift goes into the void ( 2 ). In this case, only the lever on the first actuation side is used 1b on the first cam 18th tapped full valve lift via the first valve-side lever 1a on the outlet gas exchange valves 4th , 5 transfer. At the same time is the second lever on the valve side 2a through the third coupling agent 11th with the third lever on the actuation side 2 B coupled ( 4th ). This will open the inlet gas exchange valves 6th , 7th via the second lever on the valve side 2a with that of the first lever on the actuation side 1b on the third cam 20th tapped valve full stroke actuated ( 2 ). The deactivated actuators 12th , 14th are located with the in the sockets 38 , 39 retracted anchors 12a , 14a each in at least partial axial overlap with the end faces of the actuator-side ends of the first and third actuating piston 9a , 11a , the one with the first or second valve-side lever 1a , 2a is pivoted ( 4th and 6th ). Thereby the first and second coupling means 9 , 11th by the first and third actuators 12th , 14th permanently controllable without delay. This is also made possible by the fact that the actuators 12th , 14th in the carrier 16 and the coupling agent 9 , 11th in the levers on the valve side 1a , 2a close to the rocker arm axis 3 are arranged and therefore the absolute movement of the actuating piston 9a , 11a during a pivoting movement of the lever on the valve side 1a , 2a is low, even with a full valve lift.

Since in the first switching state according to 5 the second actuator 13th is deactivated, the second coupling piston is 10a by the spring force of the associated spring means 30th moved to the decoupled position. It lies with its mushroom-shaped widened end on the actuator side 41 on the front of the first arm 36b of the wearer 36 axially. With the mushroom-shaped end 41 the second coupling piston slides 10a upon a pivoting movement of the second lever on the actuation side 1c on the front of the first arm 36b back and forth. In this way he is against falling out of the through hole 33 on the carrier 36 secured.

In the in 6th The illustrated second switching state of the rocker arm arrangement is only the first and the third actuator 12th , 14th activated. In doing so, the anchors are extended 12a , 14a the first and third coupling means 9 , 11th moved into the decoupled position and the first valve-side lever 1a from the first lever on the actuation side 1b and the third lever on the valve side 2a from the third lever on the actuation side 2 B decoupled. Because the second actuator 12th is deactivated, is the second lever on the actuation side 1c from the first lever on the valve side 1a decoupled. This creates the first lever on the valve side 1a and the second valve-side lever 2a deactivated. The decoupled first and the decoupled third actuation-side lever 1b , 2 B are in the idle stroke, because of these on the first or on the second cam 18th , 19th tapped valve full lift goes nowhere ( 2 ). This makes both rocker arms 1 , 2 switched off and do not transfer any valve lift to the gas exchange valves 4th , 5 respectively. 6th , 7th ( 2 ). In this way, cylinder deactivation is implemented in the second operating state of the rocker arm arrangement.

To 7th is the second actuator in a third switching state of the rocker arm assembly 13th activated while the first actuator 12th is deactivated. The anchor 13a of the second actuator 13th has moved out. Here is the first lever on the valve side 1a via the second coupling agent 10 with the second lever on the actuation side 1c coupled and that of the latter on the second cam 19th tapped additional valve lift is transferred to the former ( 3 ). Since at the same time the first lever on the valve side 1a through the first coupling agent 9 with the first lever on the actuation side 1b is coupled ( 4th ), that of the latter on the first cam 18th Transfer tapped full valve lift to the former ( 3 ). This is where the outlet gas exchange valves 4th , 5 through the first lever on the valve side 1a with the valve full stroke of the primary cam 18th and through the switchable additional valve lift of the secondary cam 19th controlled.

In a fourth switching state of the rocker arm arrangement, the first actuator 12th activated and the first lever on the valve side 1a through the first coupling agent 9 from the first lever on the actuation side 1b be decoupled. The latter reaches the idle stroke. In this way, only the lever from the second actuation side is activated 1c on the secondary cam 19th additional valve lift tapped by the first valve-side lever 1a on the outlet gas exchange valves 4th , 5 transfer ( 3 ).

The actuators 12th , 13th , 14th with the anchors 12b , 13b , 14b and the coupling agent 9 , 10 , 11th in the holes 27 , 28 , 34 and the through holes 25th , 26th , 33 are each parallel to the rocker arm axis 3 and transversely to the longitudinal axis of the rocker arm 1 , 2 arranged to be slidable for switching. This is how the rocker arms are 1 , 2 switchable by a space-saving so-called cross locking, which at the same time provides an arrangement of the coupling means 9 , 10 , 11th allows near the rocker arm axis.

The rocker arms 1 , 2 are through the actuators 12th , 13th respectively. 14th each individually operable. The lifting magnets of the actuators 12th , 13th , 14th can be controlled via control electronics (not shown). For this purpose, a central contact, in particular a central plug, is integrated into the rocker arm arrangement. A connection to the engine control, which is not shown here, can be arranged outside the cylinder head of the internal combustion engine. The lifting magnets can be activated by a switching command from the motor control, a so-called Can signal. The integrated electronics take care of the calculation of the exact time of energization of the lifting magnets. The integrated electronics also decide which of the individual lifting magnets is controlled.

The rocker arm arrangement can according to 8th in a simple way with the rocker arm axis 3 by a second screw connection 42 directly on the indicated cylinder head 43 the internal combustion engine are attached. There are several screws in the screw connection for this purpose 42 each in the area of the base plate 36a of the wearer 36 through radial through holes 44 , 45 on the rocker arm axis 3 passed through and in a threaded hole 46 , 47 on the cylinder head 43 screwed ( 1 until 3 and 8th ). It is also conceivable through the first or the second screw connection 37 , 42 the rocker arm axis 3 and the carrier 36 on the cylinder head 43 to fix ( 1 until 3 ).

To 4th until 8th are return spring means 48 , 49 , 50 provided, each of the respective valve-side lever 1a , 2a and the respectively assigned lever on the actuation side 1b , 1c , 2 B Pre-tension each other into the unswiveled basic position. The return spring means 48 , 49 , 50 serve to reset the lever in the decoupled state in the basic position. First and second return spring means 48 , 49 are each between the first lever on the valve side 1a and the first and second actuation-side levers, respectively 1b , 1c and third return spring means 50 between the second lever on the valve side 2a and the third operating side lever 2 B acting arranged.

The return spring means 48 , 49 , 50 are each designed as a torsion or torsion spring, preferably as a torsion spring. They are coaxial with the rocker arm axis 3 coil-shaped in aligned axially opposite annular recesses 51 , 52 respectively. 53 , 54 respectively. 55 , 56 on the opposite axial longitudinal sides of the lever of the respective valve-side lever 1a , 2a and the respective actuation-side levers assigned to them 1b , 1c , 2 B arranged. They are each with a spring end on the respective valve-side lever 1a , 2a and with the other end of the spring on the respectively assigned lever on the actuation side 1b , 1c , 2 B clamped in the pivoting direction. In a first recess 51 on the second lever on the actuation side 1c facing away from the outer axial lever longitudinal side of the first valve-side lever 1a and in a second recess that is aligned opposite to this 52 on the inner axial lever longitudinal side of the first lever on the actuation side 1b are the first return spring means 48 recorded. Second return spring means 49 are in one of the first lever on the actuation side 1b remote inner axial lever longitudinal side of the first valve-side lever 1a trained third recess 53 and in a fourth recess corresponding to this 54 on the outer axial longitudinal side of the lever of the second lever on the actuation side 1c housed. To accommodate third return spring means 50 is a fifth recess 55 on the outer axial lever longitudinal side of the second valve-side lever 2a provided with a sixth recess 56 on the outer axial lever longitudinal side of the third lever on the actuation side 2 B corresponds. The return spring means 48 , 49 , 50 are in the recesses 51 , 52 respectively. 53 , 54 respectively. 55 , 56 each guided radially and axially.

List of reference symbols

1

rocker arm

1a

lever

1b

lever

1c

lever

2

rocker arm

2a

lever

2 B

lever

3

Rocker arm axis

4th

Gas exchange valve

5

Gas exchange valve

6th

Gas exchange valve

7th

Gas exchange valve

8th

camshaft

9

Coupling agent

9a

Actuating piston

9b

Coupling piston

10

Coupling agent

10a

Coupling piston

11th

Coupling agent

11a

Actuating piston

11b

Coupling piston

12th

Actuator

12a

anchor

12b

Return spring means

13th

Actuator

13a

anchor

13b

Return spring means

14th

Actuator

14a

anchor

14b

Return spring means

15th

Cam roller

16

Cam roller

17th

Cam roller

18th

Cams, primary cams

19th

Cams, secondary cams

20th

cam

21

Valve contact

22nd

Valve contact

23

Lever end area

24

Lever end area

25th

Through hole

26th

Through hole

27

drilling

28

drilling

29

Spring means

30th

Spring means

31

Rifle

31a

attack

32

Rifle

32a

attack

33

Through hole

34

drilling

35

Spring means

36

carrier

36a

Base plate

36b

poor

36c

poor

37

Screw connection

38

Rifle

39

Rifle

40

Rifle

41

end

42

Screw connection

43

Cylinder head

44

Through hole

45

Through hole

46

Threaded hole

47

Threaded hole

48

Return spring means

49

Return spring means

50

Return spring means

51

Recess

52

Recess

53

Recess

54

Recess

55

Recess

56

Recess

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102017129720 A1 [0002]

Claims (10)

Rocker arm arrangement for a valve drive of an internal combustion engine, with at least one rocker arm (1) which is mounted on a rocker arm axis (3) with a valve-side lever (1a) for actuating at least one gas exchange valve (4, 5) of the internal combustion engine and with two actuation-side levers (1b, 1c ) is arranged pivotably for the pivotable drive, the levers (1a, 1b, 1c) being mounted on the rocker arm axis (3) so as to be pivotable with respect to one another and a first actuation-side lever (1b) for transmission by first coupling means (9) for switching the rocker arm (1) a first lifting movement for valve actuation and a second actuation-side lever (1c) can each be coupled to the valve-side lever (1a) by second coupling means (10) for transmitting a second lifting movement for valve actuation. Rocker arm arrangement according to Claim 1 , characterized in that next to the first rocker arm (1) a second rocker arm (2) is arranged on the rocker arm axis (3), the second rocker arm (2) on the rocker arm axis (3) with a second valve-side lever (2a) for actuation at least one gas exchange valve (6, 7) of the internal combustion engine and a third pivotably drivable actuation-side lever (2b) is pivotably arranged, the levers (2a, 2b) being mounted on the rocker arm axis (3) such that they can pivot with respect to one another and for switching the second rocker arm (2 ) the third lever (2b) on the actuation side can be coupled to the second lever (2a) on the valve side by third coupling means (11) for transmitting a third stroke movement for valve actuation. Rocker arm arrangement according to Claim 2 , characterized in that the first valve-side lever (1a) is in valve contact with at least one outlet gas exchange valve (4, 5) of the internal combustion engine and the second valve-side lever (2a) is in valve contact with at least one inlet gas exchange valve (6, 7). Rocker arm arrangement according to one of the Claims 1 until 3 , characterized in that the first lever (1b) on the actuation side for tapping a full valve lift for valve operation with a first cam (18) of a camshaft (8) of the internal combustion engine and the second lever (1c) on the actuation side for tapping off an additional valve lift for valve operation with a second cam (19) of the camshaft (8) and the third actuation-side lever (2b) for tapping a full valve lift for valve actuation is in contact with a third cam (20) of the camshaft (8). Rocker arm arrangement according to one of the Claims 1 until 4th , characterized in that the respective coupling means (9, 10, 11) are each assigned an actuator (12, 13, 14) for switching, the actuators (12, 13, 14) being designed as electrical lifting magnets, each one linear displaceable armature (12a, 13a, 14a) by means of which the respective coupling means (9, 10, 11) can be displaced for switching in direct actuating contact. Rocker arm arrangement according to one of the Claims 1 until 5 , characterized in that the actuators (12, 13, 14) are at least partially integrated into a carrier (36) connected to the rocker arm axis (3) and are arranged at a radial distance from the rocker arm axis (3). Rocker arm arrangement according to one of the Claims 1 until 6th , characterized in that the coupling means (9, 10, 11) in respectively assigned axial bores (25, 27 and 26, 28 or 33, 34) on the valve-side levers (1a, 2a) and on the respectively assigned actuation-side levers ( 1b, 1c, 2b) are arranged to be axially displaceable for switching. Rocker arm arrangement according to one of the Claims 1 until 7th , characterized in that coupling means (9a, 10a, 11a) and at least one actuator (12, 13, 14) assigned to it for switching are slidably integrated in at least one lever (1a, 2a) on the valve side or in a lever (1c) on the actuation side for switching are arranged such that when the respective valve-side lever (1a, 2a) or actuation-side lever (1b) is pivoted relative to the respective actuator (12, 13, 14), an at least partial overlap in the displacement direction between the coupling means (9a, 10a, 11a ) and the actuator (12, 13, 14) for switching is guaranteed. Rocker arm arrangement according to one of the Claims 1 until 8th , characterized in that coupling means (10a) which are slidably integrated into at least one actuation-side lever (1c) for switching and at least one actuator (13) assigned to this for actuation and integrated in a carrier (36) are arranged in such a way that when the actuation-side Lever (1c) opposite the carrier (36), the coupling means (10a,) on the actuator side in the decoupled state on the carrier (36) can be applied in the displacement direction. Rocker arm arrangement according to one of the Claims 1 until 9 , characterized in that return spring means (48, 49, 50) are provided which each preload at least one actuation-side lever (1b, 1c, 2b) and the respective valve-side lever (1a, 2a) in the pivoting direction against each other into a non-pivoted basic position respective actuation-side levers (1b, 1c, 2b) and on the respective valve-side lever (1a, 2a) on the axially opposite lever longitudinal sides In each case axially aligned opposing recesses (51 to 56) are provided, in which the return spring means (48, 49, 50) are each at least partially arranged and each braced in the pivoting direction.

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