EP2181251B1 - Internal combustion engine valve drive switching device - Google Patents

Description

The invention relates to an internal combustion engine valve drive switching device according to the preamble of claim 1.

From the DE 10 2005 006 489 A1 For example, an internal combustion engine valve drive switching device is known in which coupled switching operations are performed simultaneously.

The invention has the object of providing a valve train switching device in such a way that both construction volume and weight as well as costs can be saved at a high reliability. The object is achieved in each case by the features of the independent claims, wherein further embodiments of the invention can be taken from the subclaims.

The invention is based on an internal combustion engine valve drive switching device with a switching unit.

It is proposed that the switching unit has an execution unit which is provided to execute a second switching operation on the basis of at least one signal, a first switching operation and then independently of an electronic evaluation. A "switching unit" is to be understood in particular as meaning a unit which is intended to effect a switching operation of at least one valve drive. "Provided" is to be understood in particular to be specially equipped and / or designed. In this context, a "signal" is intended in particular to mean a triggering process and / or a sign, such as, for example, a current pulse with a defined meaning and / or an application initiated from outside the execution unit and / or positioning a mechanical component in a switching position and / or mechanical interaction are understood. A "triggering process" is to be understood in particular as meaning a mechanical, electrical, quantum-mechanical and / or electromechanical process, which in particular can lead to a specific positioning of a switching means. By "execution unit" is meant in particular a unit which executes at least one operation due to a signal once and which in particular of mechanical, quantum mechanical, electrical and / or electromagnetic components and in particular also of electronic components, if these at least negligible and the process not particularly advantageous, may be formed. A "switching operation" should be understood in particular to mean a relative movement and in particular an axial relative movement between two components. The fact that a switching operation takes place "after" another switching operation, should be understood in particular that the switching operations take place at least partially offset in time and / or are particularly advantageous temporally overlapping. An electronic "evaluation" is intended in particular to mean an electronic classification and / or evaluation of a state and / or a signal and / or a process. By performing "independently" of an electronic evaluation, it is intended in particular to mean an automated execution in a mechanical, quantum mechanical, electrical and / or electromagnetic manner. With an embodiment according to the invention, a simple construction of the switching unit can be achieved.

In a preferred embodiment of the invention, the execution unit is at least partially formed as a mechanical unit. This can save design costs.

It is also proposed that the execution unit is at least partially designed as a transmission. Thus, a simple construction of the execution unit can be achieved. The transmission can be designed in particular as a cam gear. Furthermore, other, the expert appear appropriate sense gearbox conceivable, such as gear transmission, lever mechanism, hydraulic transmission, etc.

Advantageously, the execution unit is provided to switch over a valve train and / or change at least one valve lift curve and / or shutdown to effect at least one valve and / or at least one change of operating modes of an internal combustion engine. Hereby, a simple and efficient operation of the valves of a valve train can be achieved. A "valve train" is to be understood, in particular, as a structural unit which is intended to allow, at least in part, a gas exchange in internal combustion engines which are based on a reciprocating piston engine. A "switching over" of a valve train should in particular be understood to mean a change process for changing at least one property and / or at least one function of the valve train and / or changing between different operating modes. By a "valve lift curve" is meant the graph of the function obtained by measuring the valve lift, which is measured relative to the cylinder to which the valve is associated, above the rotation angle of the drive shaft associated with the valve train in a Cartesian coordinate system applying. By "different operating modes" should be understood in particular the operation of valves with different timing and / or valve lift curves. A "change of operating modes" is to be understood here in particular as meaning the operation of the internal combustion engine at full load, at partial load, in auto-ignition mode, with cylinder deactivation, with early or late inlet closure or further modes of operation which appear reasonable to the person skilled in the art.

In an advantageous embodiment of the invention, the execution unit comprises at least one switching means and at least two switching units, and the execution unit is provided to actuate the switching units independently of one another in at least one operating mode, at least as a function of the positions of the switching units relative to the switching means. Thus, the number of required switching means can be reduced. A "switching means" is to be understood in particular a means which is intended to effect a switching operation, in particular also in cooperation with at least one switching unit or another unit. A "switching unit" is to be understood in particular as meaning a unit which is intended to effect a switching operation, in particular also in cooperation with at least one switching means or another unit. The fact that the execution unit "actuates" a switching unit should in particular mean cooperation and / or interaction of the execution unit or parts of the execution unit with the switching unit, which can bring about a switching operation. Under that the execution unit the switching units "independently In particular, it should be understood that actuation of a switch unit by the lead-out unit does not affect actuation of another switch unit by the lead-out unit A "mode of operation" is to be understood in particular as a mode of operation.

In a preferred embodiment of the invention, the execution unit comprises at least two switching units and at least one switching means, which is provided to actuate the at least two switching units at least partially offset in time in at least one operating mode. Hereby, the number of required switching means can be reduced.

It is also proposed that the execution unit has at least two switching units and at least one switching means, which is provided to actuate one of the switching units in dependence on at least one change in position of at least one of the switching units relative to the switching means. Hereby, the number of required switching units and the number of necessary switching means can be reduced.

It is also proposed that the execution unit has at least two switching devices assigned to different switching means. Thus, a switching operation can be designed in a component saving manner. A "switching direction" is to be understood in particular a direction in which a component is moved relative to the switching means in an at least partially caused by the switching means switching operation, in particular is moved in translation. In principle, superimposed movements, such as translational and rotational movements are conceivable.

Advantageously, the execution unit comprises at least one switching means and at least two switching units corresponding to the switching means, and the switching units are at least partially decoupled in their movement. Thus, the switching units can be moved relative to the switching means in different directions. In particular, one switching unit may rest relative to the switching means while another switching unit moves relative to the switching means. A switching unit "corresponding" to the switching means is to be understood in particular a switching unit which is designed such that it in a cooperation with the switching means a Switching allows. Switching units which are at least partially "decoupled" in their movement should, in particular, be understood as switching units for which at least one movement of a switching unit relative to the other switching unit runs independently of the latter in at least one operating mode.

Furthermore, it is proposed that the execution unit is provided to actuate at least two switching units simultaneously in at least one operating mode. This can be achieved in a structurally simple manner that a switching means can actuate two switching units at least partially decoupled.

In a preferred embodiment of the invention, the execution unit has at least two switching units and at least two control means, which are positioned on mutually facing ends of the at least two switching units of the execution unit. In particular, the extent of the individual control means can thus be reduced. A "control means" is to be understood in particular as means for controlling a process, in particular for controlling a switching operation. In particular, the switching units may be associated with different valves, which in particular may be associated with different cylinders. For a particularly flexible circuit, the switching units can be associated with only one valve.

Preferably, the control means form at least one control link. This can be realized in a simple manner, a switching device for switching operations between the switching units and the switching means. A "control link" is to be understood in particular at least one molding or several moldings together with their boundaries, which are intended to guide a switching means in at least one switching operation, and individually or together over a certain angular range, as preferably over more than 10 °, advantageously over more than 80 ° and more preferably over more than 180 °, extend in the circumferential direction of a drive shaft or connected to a drive shaft component, wherein the formations may be spatially separated from each other and this spatial separation can be canceled by a switching operation. A "shaping" should in particular be understood to mean an elevation or a recess which may have various forms of extension that appear appropriate to the person skilled in the art, such as, in particular, an elongated extension shape. A molding can in particular a slot or a groove. A "slot" is to be understood in particular a narrow recess. By a "survey" is meant in particular an elevated location compared to the area surrounding the site and / or a bulge meant.

In a preferred embodiment of the invention, the internal combustion engine valve drive switching device comprises at least one control link, which is formed by at least two switching units of the execution unit. This can be realized in a particularly simple manner, a switching device for switching operations in which the switching units are involved.

Preferably, the control link is designed such that the switching units can be actuated by a switching means in a defined switching sequence. Thus, the control scenes can be used in a continuous operation. A "defined switching sequence" should be understood in particular to take place according to a defined procedure and at least partially offset in time and / or separate switching operations, which are particularly suitable for permanent operation with at least two occurring defined switching sequences.

It is also proposed that the execution unit has at least one control link and at least one switching means, which are provided to effect a switching of a valve drive by an interaction. Hereby, a reliable change of valve lift curves can be achieved.

Preferably, the execution unit has at least one switching means and at least one switching unit having at least one control means, wherein the control means and the switching means are provided to change at least one function of the switching unit and / or the switching means due to interaction with each other. Hereby, a compact switching structure can be achieved. By a "function" is meant in particular a mode of action and in particular a mode of action in an interaction with another structural unit, which may be, for example, the switching means or the switching unit.

In this context, an advantage can be achieved by the function of immersing the switching means in the switching unit and / or pushing out the Switching means of the switching unit and / or an actuation of the switching unit by the switching means and / or a change over of the switching means from a switching unit to another switching unit and / or calming the movement of a switching unit. Thus, an effective mechanical switching device can be realized. With a "dipping" of the switching means in the switching unit in particular a retraction of trained as a survey or pen as switching means should be meant in a groove or a slot of a switching unit. By "pushing out" of the switching means from the switching unit, in particular the removal of the switching means designed as an elevation or as a pin should be understood by pushing out of the groove or the slot of the switching unit. A "calming down" of the movement of a switching unit should also be understood to mean an immobilization of the switching unit relative to the switching means after a movement of the switching unit relative to the switching means.

Preferably, at least one switching means is provided to act on at least one control link in at least one radial direction. This allows a structurally simple interaction between switching means and control link can be achieved. A "radial direction" is to be understood in particular a direction radially with respect to a drive shaft. By "acting on" the control link by the switching means is meant in particular that the switching means is intended to impinge upon movement to a formation of a control link and / or to act with a force.

It is also proposed that the execution unit has a camshaft, at least a large part of which switching units, through which valve lift curves of valves, which are associated with the camshaft changeable, and at least one switching means, which is intended to actuate the switching units. This can be a coherent switching achieved and thus a malfunction of individual cams are prevented. In particular, at least fifty percent, in particular at least seventy percent, and particularly advantageously at least ninety percent, of the total number should be meant by a "majority". A valve should in particular be "assigned" to a camshaft when the valve is indirectly or directly opened and / or closed by means of the camshaft.

Preferably, the execution unit comprises a switching means, which is designed as a switching pin. For a cost-effective design of the switching means is possible.

Advantageously, the Ausführeinheit comprises at least one switching unit and at least one switching means, which are provided to effect by interacting with each other an axial displacement of the switching unit relative to the switching means and thereby switching a valve train. Hereby, the valve train can be switched in a structurally simple way. An "axial" displacement of the switching unit should in particular be understood to mean a displacement of the switching unit in a main extension direction of a drive shaft, which may be a camshaft.

Furthermore, it is proposed that the execution unit has at least one switching unit, which is designed as an axially displaceable portion of a camshaft with cams with at least partially different contour. In this way, the switching unit can immediately perform a switching operation on a cam. A "cam" is intended in particular to mean a curved projection on a shaft which rotates in an operating mode and which may be designed as a camshaft. An "at least partially differently shaped contour" is to be understood in particular as meaning a different extent of the projections of different cams and / or of a cam.

In a preferred embodiment of the invention, the execution unit comprises at least one switching unit, which has at least two, depending on their position relative to each other at least one switching operation causing switching elements. This can be changed in a structurally simple manner by means of a switching means all valve lift curves of a camshaft, which avoids that the valves of a camshaft unintentionally operated with different valve lift curves and the exhaust emission of the internal combustion engine are adversely affected.

Preferably, the execution unit comprises at least one switching unit with at least one energy storage element, which is provided to at least partially store energy emitted during a switching operation. In this way, the number of switching means required for a camshaft can be reduced. The energy storage element can be formed by various mechanical, chemical and / or electrical storage elements that appear appropriate to the person skilled in the art.

Advantageously, the energy storage element causes by means of a stored energy a switching operation, whereby an advantageous use of energy can be achieved, and in particular a time delay relative to the actuation of the switching unit by the switching means time-delayed axial displacement of a cam can be achieved.

In one embodiment, the execution unit comprises a switching means, which is designed as a push rod, whereby this can be structurally simple and space-saving integrated and in particular structurally designed simply as springs energy storage elements for a switching operation can be prestressed.
It is also proposed that the execution unit has at least one switching means, at least one armature and at least one threaded spindle, which is intended to displace the switching means axially in cooperation with the armature. In this way, an advantageous power flow can be achieved and, in particular, mechanical energy of a rotational movement in the energy storage elements can be stored in a structurally simple manner.

Further advantages emerge from the following description of the drawing. In the drawings, embodiments of the invention are shown. The description and claims contain numerous features in combination. The person skilled in the art will expediently also consider the features individually and combine them into meaningful further combinations.

Fig. 1

Teile einer Brennkraftmaschinenventiltriebumschaltvorrichtung mit einer Umschalteinheit,

Fig. 2

eine Abwicklung einer Steuerkulisse,

Fig. 3

eine Draufsicht auf Abwicklungen zweier Steuerkulissen,

Fig. 4a und 4b

einen Zwischenzustand bei einem ersten Schritt eines Schaltvorgangs nach rechts,

Fig. 5a und 5b

einen Zwischenzustand bei einem zweiten Schritt des Schaltvorgangs nach rechts,

Fig. 6a und 6b

einen Zwischenzustand bei einem dritten Schritt des Schaltvorgangs nach rechts,

Fig. 7a und 7b

einen Zwischenzustand bei einem vierten Schritt des Schaltvorgangs nach rechts,

Fig. 8a und 8b

einen Zwischenzustand bei einem fünften Schritt des Schaltvorgangs nach rechts,

Fig. 9a und 9b

einen Zwischenzustand bei einem sechsten Schritt des Schaltvorgangs nach rechts,

Fig. 10a und 10b

einen Zwischenzustand bei einem siebten Schritt des Schaltvorgangs nach rechts,

Fig. 11a und 11b

einen Zwischenzustand bei einem achten Schritt des Schaltvorgangs nach rechts,

Fig. 12a und 12b

einen Zwischenzustand bei einem ersten Schritt eines Schaltvorgangs nach links,

Fig. 13a und 13b

einen Zwischenzustand bei einem zweiten Schritt des Schaltvorgangs nach links,

Fig. 14a und 14b

einen Zwischenzustand bei einem dritten Schritt des Schaltvorgangs nach links,

Fig. 15a und 15b

einen Zwischenzustand bei einem vierten Schritt des Schaltvorgangs nach links,

Fig. 16a und 16b

einen Zwischenzustand bei einem fünften Schritt des Schaltvorgangs nach links,

Fig. 17a und 17b

einen Zwischenzustand bei einem sechsten Schritt des Schaltvorgangs nach links,

Fig. 18a und 18b

einen Zwischenzustand bei einem siebten Schritt des Schaltvorgangs nach links,

Fig. 19a und 19b

einen Zwischenzustand bei einem achten Schritt des Schaltvorgangs nach links,

Fig. 20

einen Schnitt durch ein alternatives Ausführungsbeispiel einer Brennkraftmaschinenventiltriebumschaltvorrichtung mit einer Ausführeinheit,

Fig. 21

einen Teil einer Schalteinheit,

Fig. 22

einen Teil einer Nockenwelle und

Fig. 23

einen Teil der Ausführeinheit.

Showing:

Fig. 1

Parts of an internal combustion engine valve drive switching device with a switching unit,

Fig. 2

a settlement of a tax law,

Fig. 3

a plan view of developments of two control scenes,

Fig. 4a and 4b

an intermediate state at a first step of a shift to the right,

Fig. 5a and 5b

an intermediate state at a second step of the shift to the right,

Fig. 6a and 6b

an intermediate state at a third step of the shift to the right,

Fig. 7a and 7b

an intermediate state at a fourth step of the shift to the right,

Fig. 8a and 8b

an intermediate state at a fifth step of the shift to the right,

Fig. 9a and 9b

an intermediate state at a sixth step of the shift to the right,

10a and 10b

an intermediate state at a seventh step of the shift to the right,

Fig. 11a and 11b

an intermediate state at an eighth step of the shift to the right,

Fig. 12a and 12b

an intermediate state at a first step of a shift to the left,

Fig. 13a and 13b

an intermediate state at a second step of the shift to the left,

Figs. 14a and 14b

an intermediate state at a third step of the shift to the left,

Figs. 15a and 15b

an intermediate state at a fourth step of the shift to the left,

Fig. 16a and 16b

an intermediate state at a fifth step of the shift to the left,

Figs. 17a and 17b

an intermediate state at a sixth step of the shift to the left,

Figs. 18a and 18b

an intermediate state at a seventh step of the shift to the left,

FIGS. 19a and 19b

an intermediate state at an eighth step of the shift to the left,

Fig. 20

a section through an alternative embodiment of an internal combustion engine valve drive switching device with an execution unit,

Fig. 21

a part of a switching unit,

Fig. 22

a part of a camshaft and

Fig. 23

a part of the execution unit.

FIG. 1 shows an internal combustion engine valve drive switching device with a switching unit 36, the two actuators 64, 65, a camshaft 46 and a Execution unit 38 which is intended to perform a second switching operation on the basis of a signal, a first switching operation and then independently of an electronic evaluation. The execution unit 38 has exclusively mechanical components and is consequently designed as a mechanical unit 40. Furthermore, the execution unit 38 comprises two switching means 3, 4, each formed by a switching pin, which can be actuated by the actuators 64, 65 or moved out of the actuators 64, 65. In addition, the execution unit 38 comprises switching units 1, 2, which are parts of the camshaft 46. The switching units 1, 2 have a common main extension direction, which coincides with a main extension direction of the camshaft 46. The switching means 3, 4 also have a common main extension direction which extends radially to the camshaft 46 and to the switching units 1, 2.

The switching means 3, 4 are each provided to actuate the two switching units 1, 2. In the extension of a switching means 3, 4, which takes place in its main direction of extension to the switching units 1, 2, first a loading of a switching unit 1, 2 and then an interaction between the switching means 3, 4 and the switching units 1, 2 takes place, which based on the FIGS. 4a to 19b is described and due to which an axial displacement of the switching units 1, 2 takes place relative to the switching means 3, 4 along the main extension direction of the switching units 1, 2. With the axial displacement of the switching units 1, 2 is an axial displacement of belonging to the switching units 1, 2 cams 7, 8, 48, 50, 26, 27, 28, 29, 30, 31 instead. The cams 7, 8 and 48, 50 have a different contour such that the maximum radial extent of the cams 8, 50 differs from the maximum radial extent of the cams 48, 7. Since the camshaft 46 comprises only the cams 7, 8, 48, 50, 26, 27, 28, 29, 30, 31, both switching means 3, 4 can each have those switching units 1, 2, through which valve lift curves of valves, that of the camshaft 46 are assigned, are changeable, press.

The switching unit 1 has a control means 52 which through sections 9, 11, 13, 16, 18 (see FIG. 3 ), which are formed by four grooves is formed. Furthermore, the switching unit 2 has a control means 54, which by sections 10, 12, 14, 15, 17 (see FIG. 3 ), which are formed by four grooves is formed. The control means 52, 54 are positioned in end regions or on ends 56, 58 of the switching units 1, 2, which in the main direction of extension of the camshaft 46 face each other and directly are adjacent. The control means 52, 54 form two control slots 5, 6, which are arranged one behind the other in the main direction of extension of the camshaft 46. The control scenes 5, 6 are thus each formed by the two switching units 1, 2.

The switching means 3, 4 are arranged so that they can act on the control gates 5, 6 in the radial direction in a switching operation. The switching means 3, 4 are arranged along the main direction of extension of the camshaft 46 in the same sequence as the control tracks 6, 5 one behind the other. The switching means 3 can act on the control link 6 and the switching means 4, the control link 5.

FIG. 2 shows a development of one of the control blocks 5 or 6, which extends over more than one camshaft revolution, and about 540 °. In principle, other angle ranges which appear reasonable to the person skilled in the art are also conceivable.

According to the invention, each of the control slots 5, 6 allows a change of the switching means 3, 4 during a switching operation from one switching unit 2 to another switching unit 1 and back.

FIG. 3 schematically shows a plan view of the developments of the control blocks 5 and 6, which form a gear 42 which is formed as a cam gear. The settlement of the two control scenes 5, 6 is formed by two L-shaped parts of a settlement of the switching units 1, 2, which have a rectangular shape between two switching operations, in which different switching means 3, 4 are involved. An L-shaped part comprises in each case two halves of the control slots 5, 6, which belong to different control slots 5, 6. The control blocks 5, 6 have the sections 9 to 18, which cause different functions of the switching means 3, 4 and / or the switching units 1, 2 in interaction with the switching means 3, 4, wherein the different sections 9 to 18 of the control blocks 5, 6 as a function of the angle of rotation of the camshaft 46 (see FIG. 1 ) come into operative connection with the switching means 3, 4.

The sections 9 to 18 are immersion sections 9 and 10, operating sections 11 and 12, Ausschiebeabschnitte 13 and 14, transition sections 15 and 16 and reassurance sections 17 and 18. The functions is a dipping of the switching means 3, 4 in the Immersion section 9, 10 of the control link 5 or 6, a pushing out of the switching means 3, 4 of a Ausschiebeabschnitt 13, 14 of the control link 5 or 6, operating at least one of the switching units 1 or 2, by the switching unit 1, 2 on the in the operating section 11th , Switching the switching means 3, 4 from one of the switching units 1, 2 to another switching unit 1, 2 and calming the switching movement of one of the switching units 1, 2. The switching means 3, 4 come in Dependence on the direction of rotation of the camshaft 46 with the sections 9 to 18 in different sequence in operative connection.

The FIGS. 4a, 4b to 11a, 11b and 12a, 12b to 19a, 19b show on the basis of individual intermediate states, a changeover of valve trains, which by the cams 7, 8, 48, 50 of the camshaft 46 (see FIG. 1 ) are actuated by axial displacement of the two switching units 1, 2, wherein in the Figures 4a, 4b to 11 a, 11b the switching process to the right and in the Fig. 12a, 12b to 19a, 19b the shift is shown to the left. In the switching operation to the left, the switching units 1, 2 move such that the ends 56, 58 relative to the switching means 3, 4 in the direction of the cams 48, 50 in a main extension direction 62 (see FIGS. 16a and b ) of the camshaft 46 (see FIG. 1 ). When switching to the right, the switching units 1, 2 move in a direction opposite main extension direction 60 (see FIGS. 5a and 5b ). The switching operations to the right and to the left each consist of two switching operations in which the individual switching units 1, 2 are moved relative to the switching means 3, 4 in the axial direction.

In the following, the switching operation is executed to the right. In a first step according to Fig. 4a and 4b is the right switching means 3 by the actuator 65 (see FIG. 1 ) is retracted into the immersion section 9 of the control link 6 due to a signal given by the actuator 65 in the form of a magnetic field. In a second step according to Fig. 5a and 5b is the right switching means 3 in the operating portion 12 of the control link 6 and starts the right switching unit 2 in the main extension direction 60 of the camshaft 46 (see FIG. 1 ), which is an axial direction. In a third step according to Fig. 6a and 6b the displacement of the right switching unit 2 is calmed, and then completed. After shifting the switching unit 2, which is a position change relative to the switching means 3, 4, the switching means 3 actuates the switching unit 1. In a fourth step according to Fig. 7a and 7b is the right switching means 3 just before the operating portion 11 of the control link 6 of the switching unit 1. In a fifth step according to Fig. 8a and 8b is the right switching means 3 in the operating portion 11 of the control link 6 of the left switching unit 1 and starts with its displacement in the main extension direction 60. In a sixth step according to Fig. 9a and 9b the displacement of the left switching unit 1 is completed. In a seventh step according to 10a and 10b is the right switching means 3 in the Ausschiebeabschnitt 14 of the control link 6 of the right switching unit 2 and is pushed back into the starting position in the direction of a vertical axis 19, which in the radial direction relative to the camshaft 46 (see FIG. 1 ) runs. In an eighth step according to Fig. 11a and 11b is the right switching means 3 back to the starting position. The two switching operations in which the switching units 1, 2 are shifted to the right relative to the switching means 3, 4, so run after the actuator 64 or the actuator 65 (see FIG. 1 ) has given the signal automatically with rotating camshaft 46, ie without further, coming from outside of the execution unit 38 signals. The same applies to the switching operations in which the switching units 1, 2 are successively moved to the left. Although during the first half of a shift to the left or to the right, in which a shift unit 1, 2 is shifted, an angular speed at which the camshaft 46 rotates, can change, finds the second half of the switching operation in which the other switching unit 1, 2 is axially displaced in the same direction, automated and independent of an electronic measurement of the angular velocity or other electronic evaluation instead.

The following describes the switching operation to the left. In a first step according to Fig. 12a and 12b is the left switching means 4 by the actuator 64 (see FIG. 1 ) is retracted into the immersion section 10 of the control link 5 due to a signal given by the actuator 64. In a second step according to Fig. 13a and 13b is the left switching means 4 just before the beginning of the operating portion 11 of the control link 5 in the left switching unit 1. In a third step according to Figs. 14a and 14b is the left switching means 4 in the operating portion 11 of the control link 5 of the left switching unit 1 and starts the left switching unit 1 in the main extension direction 62, which is also an axial direction to move. In a fourth step according to Figs. 15a and 15b the shift of the left switch unit 1 to the left is completed. In a fifth step according to Fig. 16a and 16b begins the shift of the right switching unit 2 in the Main extension direction 62 to the left. In order to shift the switching units 1, 2 to the left, the switching means 4 must therefore actuate the switching units 1, 2 independently of each other. In a sixth step according to Figs. 17a and 17b the displacement of the right switching unit 2 is calmed, and then completed. In a seventh step according to Figs. 18a and 18b is the left switching means 4 in the Ausschiebeabschnitt 13 of the control link 5 of the left switching unit 1 and is pushed back into the starting position in the direction of a vertical axis 20. In an eighth step according to FIGS. 19a and 19b is the left switching means 4 back to the starting position. When changing over the switching means 4 of a switching unit 1, 2 to another switching unit 1, 2, both switching units 1, 2 are operated simultaneously at times. The same applies to the switching process to the right. In all described switching operations, the switching means 3, 4 correspond to the switching units 1, 2.

Due to the nature of the control blocks 5, 6, the two switching units 1, 2 can be actuated by the switching means 3, 4 in a defined switching sequence. The switching operations to the left and to the right can therefore be repeated as often as desired in alternating order. The switching units 1, 2 are brought by the control scenes 5, 6 to the immersion, actuation, change over and calm again and again in different switching states.

In the switching operations to the left or to the right, the switching units 1, 2 are shifted individually and successively in the same direction to the left or to the right. The switching units 1, 2 are in their movement in the main direction of extension of the camshaft 46 (see FIG. 1 ) so partially decoupled.

With reference to the described switching operations it can be seen that by means of the left switching means 4 switching operations to the left and by means of the right switching means 3 switching operations are executed to the right. Thus, each switching means 3, 4 each assigned a switching direction.

In the described switching of the valve trains the valve lift curves of valves, which are opened and closed due to the rotation of the camshaft 46 in an operating mode, are changed. Furthermore, valves can be switched off by the switching and thus remain closed. With a change of Valve lift curves may be accompanied by a change in the operating modes of the internal combustion engine.

In the FIGS. 20 to 23 an alternative embodiment is shown. Substantially identical components, features and functions are basically numbered by the same reference numerals. To distinguish the embodiments, however, the reference number of the alternative embodiment in the FIGS. 20 to 23 the letter "a" added. The following description is essentially limited to the differences from the embodiment in the FIGS. 1 to 19 , wherein with respect to the same components, features and functions on the description of the embodiment in the FIGS. 1 to 19 can be referenced.

FIG. 20 shows a section through an alternative embodiment of an internal combustion engine valve drive switching device with a switching unit 36 a. The switching unit 36a comprises an execution unit 38a and a camshaft 80. The execution unit 38a comprises three cylinder valve actuation units 82, 84, 86 which all together actuate either the exhaust and / or intake valves of a cylinder bank having a plurality of cylinders. The execution unit 38a has only mechanical components and is therefore designed as a mechanical unit 40a. Since the cylinder valve operating units 82, 84, 86 are identical in construction, only one will be described below. The cylinder valve actuating unit 82 comprises a cam segment 88, which surrounds a shaft portion of the camshaft 80 in the circumferential direction or is sleeve-shaped and axially in the direction of the main extension direction of the camshaft 80 slidably mounted on the shaft portion of the camshaft 80. The cam segment 88 is connected by means of coupling bolts 90, 92 with a switching piece 94. The contact piece 94 is clamped between two ends of coil springs 96, 98. The coil springs 96, 98 are identical to energy storage elements 146, 148. The deflection direction of the coil springs 96, 98 is identical to the main direction of extension of the camshaft 80. The ends of the coil springs 96, 98 remote from the switching piece 94 act on spring plates 100, 102, which are firmly connected to a switching means 74. The switching means 74 is designed as a push rod. Its main direction of extension is identical to the main extension direction of the camshaft 80. The switching means 74 has rotational symmetry, wherein the direction of the axis of symmetry is identical to its main extension direction. The symmetry axis agrees with the axis of rotation the camshaft 80 coincide. The camshaft 80 is formed as a hollow shaft. The switching means 74 extends in the interior of the camshaft 80. The coil springs 96, 98 and the switching piece 94 are also located in the interior of the camshaft 80. The coupling bolts 90, 92 extend in relation to the camshaft 80 in the radial direction. The cam segment 88 has cams 108, 110, 112, 114, 116, 118. The cams 108 to 112 are associated with a first valve 126 and the cams 114 to 118 are associated with a second valve 128. The two valves 126, 128 are assigned to the same cylinder. On the cam segment 88 are disposed switching elements 120, 122 which extend relative to the camshaft 80 in the circumferential direction over a camshaft rotation angle range which is smaller than 360 degrees. The switching elements 120, 122 are contacted at a different camshaft rotation angle of a switching element 124, which is relative to the cylinder final positions of the valves 126, 128 at rest. The switching elements 120, 122, 124 together with the coupling bolts 90, 92, the switching piece 94, the spring plates 100, 102 and the coil springs 96, 98, a switching unit 130th

At one end of the switching means 74, a threaded spindle 76 is fixed by positive locking. At the opposite end of the switching means 74 is located between the switching means 74 and the camshaft 80, a switching means restoring spring 144, which can be compressed by a movement of the switching means 74 in the main direction of extension of the switching means 74.

FIG. 21 shows a part of the switching unit 130 together with a part of the switching means 74. On the switching piece 94, the two coupling pins 90, 92 are fixed in the opposite direction. The two coil springs 96, 98 are biased in the main direction of the switching means 74 by means of the spring plates 100, 102 against each other. Between the coil springs 96, 98 is the switching piece 94. The switching piece 94 can be moved relative to the switching means 74 by means of a compression of the coil spring 96 or 98 in the main extension direction of the switching means 74.

FIG. 22 shows the shaft portion of the camshaft 80, which is enclosed by the cam segment 88 in the assembled state. A contact surface 132 on which the cam segment 88 (see FIG FIG. 20 ) can touch the shaft part, has a longitudinal toothing. This allows the cam segment 88, which on an im mounted state has the shaft part facing surface has a corresponding spline, a movement relative to the shaft member in the axial direction and prevents relative movement in the circumferential direction. The coupling pin 90 projects through a recess 104, which allows the coupling pin 90 to move in the axial direction. An analogous recess 106 (see FIG. 20 ) exists for the coupling pin 92.

FIG. 23 shows a magnetic stator 136 and a part of the execution unit 38a with the threaded spindle 76 in an exploded view. Hereinafter, the structure of this part of the execution unit 38a in the assembled state will be described. The threaded spindle 76 is screwed into a threaded nut 140 formed by one end of the camshaft 80 and is connected by a positive engagement with the switching means 74 such that the threaded spindle 76 is immovable relative to the switching means 74 in the main direction of extension of the switching means 74. On the side facing the threaded spindle 76, the switching means 74 has a thrust bearing 142, which rotatably supports the threaded spindle 76 and the switching means 74 about the axis of rotation of the camshaft 80. The threaded spindle 76 has a cuboidal part, which supports an armature 78 in the main direction of extension of the switching means 74 movable. In the circumferential direction of the camshaft 80, the screw shaft 76 and the armature 78 are immovable relative to each other. The threaded spindle 76 is connected to the switching means 74 by means of the axial bearing 142. A movement of the shaft part of the camshaft 80 and the threaded spindle 76 in the circumferential direction relative to the stationary magnetic stator 136 is hereby decoupled from the switching means 74. A rotation of the armature 78 in the circumferential direction of the camshaft 80 is decoupled from an armature return spring 134 by means of a thrust bearing 138. The armature return spring 134 pushes the armature 78 in the direction of the threaded nut 140 away from the magnetic stator 136. The magnetic stator 136 has a coil, through which the armature 78 can be tightened.

A switching operation of the alternative embodiment of an internal combustion engine valve drive switching device may now take place as follows. The magnetic stator 136 outputs a signal to the lead-out unit 38a by attracting the armature 78 with the aid of the coil so that the armature 78 abuts the magnetic stator 136 and is at rest relative to the magnetic stator 136. As a result, rotations of the threaded spindle 76 are prevented about the axis of symmetry of the switching means 74 relative to the magnetic stator 136. Since the nut 140, the rotations of the Due to the thread, therefore, an axial displacement of the threaded spindle 76 and the switching means 74 in the main direction of extension of the switching means 74 away from the magnetic stator 136 relative to the shaft portion of the camshaft 80 takes place instead, whereby the switching means return spring 144 is compressed. Further, this compresses the coil spring 96, whereby the coupling pins 90, 92 exert forces in the main direction of extension of the switching means 74 away from the magnet stator 136 on the cam segment 88. These forces are first compensated by a force which the switching element 124 exerts on the switching element 122 by means of contact. If now due to the camshaft rotation, the switching element 124 stops touching the switching element 122, these forces move the cam segment 88 in the main direction of the switching means 74 away from the magnetic stator 136 until the switching element 124 contacts the switching element 120. Due to the axial displacement of the cam segment 88, the cams 112 and 118, which were responsible in the initial position for a full stroke of the valves 126, 128, deactivated and the cams 110, 116 are activated, which cause a partial stroke. In this case, the coil spring 96 remains compressed in comparison to the starting position, so that further forces acting on the cam segment 88 in the main extension direction of the switching means 74 of the magnetic stator 136 away. These forces are compensated due to the contact of the switching elements 124, 120. Now stops the switching element 124 due to the camshaft rotation, the switching element 120 to touch, so achieve the force caused by the coil spring 96 on the cam segment 88 forces a further axial displacement of the cam segment 88 in the main direction of extension of the switching means 74 of the magnetic stator 136 away. Thus, the cams 110, 116 are deactivated and the cams 108, 114 are activated, which causes a switching of the valves 126, 128 from partial stroke to zero stroke. The switching elements 120, 122, 124 thus form a geometric coding for two switching operations. If the armature 78 does not abut either the magnet stator 136 or the camshaft 80, the compressed switching means return spring 144 may move the switching means 74 toward the magnet stator 136 relative to the shaft portion of the camshaft 80 in the main direction of extension of the switching means 74. As a result, the valve lift curves of the valves 126, 128 are switched from zero stroke to full stroke. In an analogous manner, the other cylinder valve actuators 84, 86 are also switched over.

Claims (18)

1. Internal combustion engine valve train switching device for a camshaft (46, 80) having axially displaceable segments, comprising a switchover unit (36, 36a) having an implementation unit (38, 38a) with at least two switching units (1, 2, 130) designed as axially displaceable segments of a camshaft (46, 80) with cams (7, 8, 26, 27, 28, 29, 30, 31, 48, 50, 108, 110, 112, 114, 116, 118) of an at least partially different contour, and further comprising at least one control gate (5, 6) which is designed such that the switching units (1, 2, 130) can, owing to characteristics of the control gate (5, 6), be actuated in a defined switching sequence by a switching means (3, 4) designed as a switching pin, the implementation unit (38, 38a) being provided for implementing a first switching operation based on at least one signal and then, independent of an electronic evaluation, a second switching operation mechanically in an automated manner,
   characterised in that
   the control gate (5, 6) is represented by the at least two switching units (1, 2, 130) designed as axially displaceable segments of the camshaft (46, 80), which are at least partially uncoupled in their movement in the main dimensional direction of the camshaft (46, 80), the control gate (5, 6) permitting a changeover of the switching means (3, 4) from one switching unit (1, 2, 130) to the other switching unit (1, 2, 130) during a switchover operation.
2. Internal combustion engine valve train switching device according to claim 1,
   characterised in that
   the implementation unit (38) comprises at least one switching means (3, 4) and at least two switching units (1, 2), and in that the implementation unit (38) is provided for actuating the switching units (1, 2) independently in at least one operating mode at least in response to the positions of the switching units (1, 2) relative to the switching means (3, 4).
3. Internal combustion engine valve train switching device according to any of the preceding claims,
   characterised in that
   the implementation unit (38) comprises at least two switching units (1, 2) and at least one switching means (3, 4) which is provided for actuating the at least two switching units (1, 2) with an at least partial time offset in at least one operating mode.
4. Internal combustion engine valve train switching device according to any of the preceding claims,
   characterised in that
   the implementation unit (38) comprises at least two switching units (1, 2) and at least one switching means (3, 4) which is provided for actuating one of the switching units (1, 2) in response to at least one positional change of at least one of the switching units (1, 2) relative to the switching means (3, 4).
5. Internal combustion engine valve train switching device according to any of the preceding claims,
   characterised in that
   the implementation unit (38) comprises at least two switching means (3, 4) assigned to different switching directions.
6. Internal combustion engine valve train switching device according to any of the preceding claims,
   characterised in that
   the implementation unit (38, 38a) comprises at least one switching means (3, 4, 74) and at least two switching units (1, 2, 130) corresponding to the switching means (3, 4, 74), and in that the switching units (1, 2, 130) are at least partially uncoupled in their movement.
7. Internal combustion engine valve train switching device according to any of the preceding claims,
   characterised in that
   the implementation unit (38, 38a) is provided for actuating at least two switching units (1, 2, 130) simultaneously in at least one operating mode.
8. Internal combustion engine valve train switching device according to any of the preceding claims,
   characterised in that
   the implementation unit (38) comprises at least two switching units (1, 2) and at least two control means (52, 54) which are positioned at facing ends (56, 58) of the at least two switching units (1, 2) of the implementation unit (38).
9. Internal combustion engine valve train switching device according to claim 8,
   characterised in that
   the control means (52, 54) form at least one control gate (5, 6).
10. Internal combustion engine valve train switching device according to any of the preceding claims,
    characterised in that
    the implementation unit (38) comprises at least one control gate (5, 6) and at least one switching means (3, 4) which are provided for effecting a switchover of a valve train by interaction.
11. Internal combustion engine valve train switching device according to any of the preceding claims,
    characterised in that
    the implementation unit (38) comprises at least one switching means (3, 4) and at least one switching unit (1, 2) having at least one control means (52, 54), the control means (52, 54) and the switching means (3, 4) being provided for changing at least one function of the switching unit (1, 2) and/or of the switching means (3, 4) on the basis of mutual interaction.
12. Internal combustion engine valve train switching device according to any of the preceding claims,
    characterised in that
    the implementation unit (38) comprises at least one switching means (3, 4) which is provided for applying pressure to at least one control gate (5, 6) in at least one radial direction.
13. Internal combustion engine valve train switching device according to any of the preceding claims,
    characterised in that
    the implementation unit (38) comprises a camshaft (46, 80), at least a major part of those switching units (1, 2, 130) by which valve lift curves of valves (126, 128) assigned to the camshaft (46, 80) can be changed and at least one switching means (3, 4, 74) which is provided for actuating the switching units (1, 2, 130).
14. Internal combustion engine valve train switching device according to any of the preceding claims,
    characterised in that
    the implementation unit (38) comprises at least one switching unit (1, 2) and at least one switching means (3, 4) which are provided for effecting, by mutual interaction, an axial displacement of the switching unit (1, 2) relative to the switching means (3, 4) and thereby a switchover of a valve train.
15. Internal combustion engine valve train switching device according to any of the preceding claims,
    characterised in that
    the implementation unit (38a) comprises at least one switching unit (130) having at least two switching elements (120, 122, 124) which effect at least one switchover operation in response to their relative positions.
16. Internal combustion engine valve train switching device according to any of the preceding claims,
    characterised in that
    the implementation unit (38a) comprises at least one switching unit (130) having at least one energy storage element (146, 148) which is provided for storing energy released in a switching operation at least partially and for effecting a switchover operation by means of the stored energy.
17. Internal combustion engine valve train switching device according to any of the preceding claims,
    characterised in that
    the implementation unit (38a) comprises a switching means (74) which is designed as a push rod.
18. Internal combustion engine valve train switching device according to any of the preceding claims,
    characterised in that
    the implementation unit (38a) comprises at least one switching means (74), at least one rotor (78) and at least one threaded spindle (76) which is provided for axially displacing the switching means (74) in interaction with the rotor (78).

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