EP2577005B1 - Actuating device for an internal combustion engine valve-train device - Google Patents

Description

The invention relates to an adjusting device for an internal combustion engine valve drive device, in particular a camshaft adjusting device, according to the preamble of claim 1.

From the DE 10 2005 037 158 A1 is already an adjusting device for an internal combustion engine valve drive device, in particular a Nockenwellenverstellvorrichtung, with a Phasenverstelleinheit having a coupling unit for adjusting a phase position in a normal operating mode, which is intended to apply a Verstellgetriebeelement with a braking force, and with an adjustment, the thereto is provided, in at least one fail-safe operating mode to set a defined Notlaufphasenlage known.

The invention is in particular the object of providing a cost-effective and simple adjusting device. It is achieved according to the invention by the features of claim 1. Further embodiments emerge from the subclaims.

The invention relates to an adjusting device for an internal combustion engine valve drive device, in particular a camshaft adjusting device, with a Phasenverstelleinheit having a coupling unit for adjusting a phase position in a normal operating mode, which is intended to apply a Verstellgetriebeelement with a braking force, and with an adjustment , which is intended to set a defined emergency running phase position in at least one fail-safe operating mode.

It is proposed that the setting unit is provided, at least in the fail-safe operating mode, for the braking force of the coupling unit of the phase adjustment unit to change. This eliminates the need for a separate coupling unit for setting the Notlaufphasenlage, which components can be saved. As a result, a complexity and a weight of the adjusting device can be kept low, whereby a cost-effective and simple adjusting device can be provided. A "setting unit" is to be understood as meaning, in particular, a unit which is provided to set a defined phase position designed as the emergency running phase position independently of an electronic control. A "Verstellgetriebeelement" is to be understood in particular a transmission element of a variable by which the phase angle and / or the adjustment of the phase position can be defined. An "adjusting mechanism" is to be understood in this context, in particular a three-shaft minus summation, by means of which the phase position can be adjusted. "Provided" is to be understood in particular to be specially equipped and / or designed.

It is further proposed that the Köppeleinheit is provided in a fail-safe operating mode for setting the Notlaufphasenlage and in a normal operating mode for adjusting an adjustment angle. As a result, one coupling unit can advantageously be used for the fail-safe operating mode and the normal operating mode, as a result of which complex actuator technology for controlling two coupling units can be dispensed with.

It is also proposed that the phase adjustment unit has a magnetic actuator which is provided to adjust the adjustment angle to set the braking force of the coupling unit magnetically. Thereby, a simple and effective Phasenverstelleinheit be realized. A "magnetically adjustable phase adjustment unit" should be understood to mean, in particular, a phase adjustment unit which is at least partially acted upon by a magnetic force to adjust the phase position, an adjustment of the phase position preferably taking place by means of an adjustment of the magnetic force. A "magnetic force" is to be understood in particular as meaning a force which can be set by means of a magnetic flux of a magnetic field. A "magnetic actuator" is to be understood in particular as a unit for providing an adjustable magnetic field and / or magnetic flux, such as a unit having at least one coil for forming an electromagnet.

In addition, it is proposed that the magnetic actuator is provided to set a displacement angle in a normal operating mode, to which the setting unit adjusts the phase position. This allows the phase position by an adjustment to a defined Adjustment angle, in particular starting from the Notlaufphasenlage as a basic phase position, can be easily adjusted by means of Magnetaktuatorik, the control can be carried out on the predetermined adjustment advantageously via the adjustment mechanism of the emergency running unit.

Preferably, the adjustment unit comprises an adjustment mechanism, which is provided for mechanically adjusting the phase position to the emergency running phase position and / or the adjustment angle. As a result, even with a failure of the normal operating mode, a phase position can be adjusted mechanically to a predetermined angle, whereby an operational safety of the phase adjustment device can be advantageously increased. An "adjustment mechanism" should be understood to mean, in particular, a unit which converts a change in the phase position merely by means of mechanical components into an adjustment of the magnetic elements. In particular, it should be understood as meaning an entity independent of electrical, pneumatic and / or hydraulic actuators.

Furthermore, it is proposed that the setting unit has at least one permanent magnet which generates a magnetic field provided for actuating the coupling unit. As a result, an advantageous fail-safe operating mode can be realized, in which the setting unit adjusts the emergency running phase position independently and independently of an external control.

In an advantageous development of the invention, it is proposed that the setting unit has at least two mutually adjustable magnetic elements which are intended to mechanically change a magnetic force for adjusting the braking force. As a result, the adjustment unit can easily adjust the phase position by advantageously changing a magnetic flux by means of the mutually adjustable magnetic elements. As a result, in particular a safe and simple mechanical control for the fail-safe operating mode can be provided. By a "magnetic element" is meant in particular a magnetizable and / or magnetized element. In particular, it should be understood to mean a ferromagnetic element, wherein the magnetic element can basically be made magnetically soft or magnetically hard. A "mechanical change of the magnetic force" is to be understood in particular that a mechanical adjustment of the magnetic elements causes a change in the magnetic force against each other.

Furthermore, it is advantageous if the coupling unit has a stationary stator and at least one first coupling element connected to the stator in an axially displaceable manner. Thereby a tolerance compensation between the stator of the coupling unit and a rotor of the coupling unit can be easily realized. In particular, axial tolerances can be easily compensated, whereby an advantageous wear compensation can be achieved. Basically, a radial tolerance compensation can be achieved by an inventive design.

In addition, it is proposed that the coupling unit has at least one further coupling element connected to the stator, which is arranged spatially spaced from the first coupling element. Thereby, a tolerance compensation between the stator of the coupling unit and a rotor of the coupling unit can be easily realized. In particular, axial tolerances can be easily compensated, whereby an advantageous wear compensation can be achieved. Basically, a radial tolerance compensation can be achieved by an inventive design.

Particularly preferably, the at least one coupling element is axially displaceably connected to the stator. Thereby, a closed Magnetflussleiteinheit be provided, whereby the magnetic flux for actuating the coupling unit can be controlled and influenced particularly advantageous.

Further, it is advantageous if the at least one coupling element is made of a magnetizable material. Thereby, the coupling elements can be advantageously designed as Magnetflussleitelemente for conducting a magnetic flux, which is provided for actuating the coupling unit. A "magnetic flux conducting element" is to be understood, in particular, as meaning a magnetically soft magnetic element that can only have a magnetic field induced by an external magnetic field. In particular, a "magnetic flux conducting element" should not be understood as a permanent magnetic element.

It is also proposed that the coupling unit has an axially fixed rotor, which is made in at least a portion of a magnetizable material. As a result, corresponding second coupling elements, which are connected to the rotor, are made particularly simple. Advantageously, the coupling elements are integrally formed with each other by means of the rotor. In addition, the magnetic flux can advantageously be passed through the rotor. An "axially fixed rotor" is to be understood in particular as meaning a rotor whose axial position is maintained when the coupling unit is actuated. Advantageously, the rotor has two fixedly connected to the rotor second coupling elements.

Further advantages emerge from the following description of the drawing. In the drawings, an embodiment of the invention is shown. The drawings, the description and the 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

eine Brennkraftmaschinenventiltriebvorrichtung mit einer erfindungsgemäßen Stellvorrichtung in einem Querschnitt,

Fig. 2

einen Ausschnitt aus der Verstellvorrichtung bei einer mittleren eingestellten Phasenlage und

Fig. 3

den Ausschnitt aus Fig. 2 bei einer Verstellung der Phasenlage nach spät.

Showing:

Fig. 1

an internal combustion engine valve drive device with an adjusting device according to the invention in a cross section,

Fig. 2

a section of the adjusting device at a medium set phase angle and

Fig. 3

the cutout Fig. 2 with an adjustment of the phase position to late.

The FIGS. 1 to 3 show an embodiment of an internal combustion engine valve drive device with an adjusting device according to the invention. The internal combustion engine valve drive device comprises a camshaft 10, which is driven by means of a crankshaft, not shown. The camshaft 10 is connected to the crankshaft by means of a chain drive. A speed of the camshaft 10 is half as large as a speed of the crankshaft. The adjusting device forms an electromagnetic camshaft adjusting device. It is intended for use in an internal combustion engine of a motor vehicle.

To adjust the phase position, the adjusting device comprises an adjusting gear 11. The adjusting 11 is designed as a 3-shaft minus totaling. It comprises three adjusting gear elements 12, 13, 14, by means of which the phase position of the camshaft 10 can be adjusted. The adjusting 11 is exemplified as a planetary gear. The adjusting device comprises a main axis of rotation 15 about which the three adjusting gear elements 12, 13, 14 are rotatably arranged. In principle, however, other 3-wave minus summation are conceivable.

To initiate a torque, the adjusting device comprises a drive unit 16, which comprises the first adjusting gear element 12. The adjusting element 12 is designed as a planet carrier, the planet gears 19 of the adjusting 11 leads on a circular path. The drive unit 16 further has a sprocket which is non-rotatably connected to the Verstellgetriebeelement 12. By means of the sprocket, the drive unit 16 is connected to the crankshaft. To derive the torque includes the adjusting device an output unit 17, which includes the second Verstellgetriebeelement 13. The adjusting element 13 is designed as a ring gear, which meshes with the guided by the planet carrier planetary gears 19. The adjusting element 13 is rotatably connected to the camshaft 10. To adjust the phase position, the adjusting device comprises a phase adjustment unit 18, which comprises the third adjusting gear element 14. The Verstellgetriebeelement 14 is formed as a sun gear, which also meshes with the guided by the planet carrier planetary gears 19.

To adjust the phase position, the phase adjustment unit 18 comprises a coupling unit 20. The coupling unit 20 is designed as a brake unit. The coupling unit 20 has an actuating direction, which is oriented parallel to the main axis of rotation 15. The coupling unit 20 includes a stationary stator 21 and a rotatably mounted rotor 22. The rotor 22 is rotatably and axially fixed to the third Verstellgetriebeelement 14 connected. He is thus fixed axially. A braking torque which can be provided by the coupling unit 20 acts on the third adjusting gear element 14. By means of the coupling unit 20, a rotational speed of the adjusting gear element 14 can be set in a defined manner. The coupling unit 20 includes two rotatably connected to the stator 21 first coupling elements 23, 24 and two rotatably connected to the rotor 22 second coupling elements 25, 26. The coupling elements 23, 24, 25, 26 each have a friction surface. The two coupling elements 23, 25, the friction surfaces are frictionally connected to each other, are arranged radially outboard. The two coupling elements 24, 26, the friction surfaces are frictionally connected to each other, are arranged radially inboard. The coupling elements 23, 24, which are rotatably connected to the stator 21, and the coupling elements 25, 26, which are non-rotatably connected to the rotor 22, are each arranged spatially spaced from each other.

The radially outer first coupling element 23 is annular. The first coupling element 23 has an inner diameter that is greater than an outer diameter of the stator 21. The radially outer coupling element 23 surrounds the stator 21. The stator 21 is arranged in a nested manner in the coupling element 23. The radially inner first coupling element 24 is also annular. The coupling element 24 has an outer diameter which is smaller than an inner diameter of the stator 21. The stator 21 surrounds the radially inner coupling element 24. The coupling element 24 is arranged in a nested manner in the stator 21.

The stator 21 is annular. On an outer circumferential surface, the stator 21 has an external toothing. On an inner circumferential surface, the stator 21 has a Internal toothing on. The external teeth and the internal teeth are designed as straight toothings. In principle, both the external toothing and the internal toothing can have other toothed forms.

The two coupling elements 23, 24 are executed separately. The outer coupling element 23 has an inner toothing corresponding to the outer toothing of the stator 21. The outer coupling element 23 is connected with its internal toothing to the outer toothing of the stator 21. Along its axially directed actuating direction, the coupling element 23 is movably coupled to the stator 21. The inner coupling element 24 has a corresponding to the internal toothing of the stator 21 external teeth. The inner coupling element 24 is connected with its external toothing to the internal toothing of the stator 21. Along its axially directed actuating direction, the coupling element 24 is movably coupled to the stator 21. The two coupling elements 23, 24 are rotationally fixed by the axial teeth and axially slidably connected to the stator 21. For movement along the actuating direction, the two coupling elements 23, 24 are independent of each other in terms of motion.

The rotor 22 is arranged axially between the stator 21 and the adjusting gear element 12 along the main axis of rotation 15. Two sections of the rotor 22 form the coupling elements 25, 26. The sections of the rotor 22, which form the coupling elements 25, 26 are made of a magnetizable material. The portion of the rotor 22 which forms the coupling element 25 is formed as an axially outer region of the rotor 22. The portion of the rotor 22 which forms the coupling element 26 is formed as an axially inner region of the rotor 22. The two sections of the rotor 22 are connected by a connector firmly together. The entire rotor 22 is made in one piece from a material. In the sections, the rotor 22 has an axial thickness that is greater than an axial strength of the connector. The two coupling elements 25, 26 are formed integrally by means of the rotor.

The phase adjustment unit 18 is magnetically adjustable. The phase adjustment unit 18 comprises a Magnetaktuatorik 27, by means of which an adjustable magnetic field can be provided for adjusting the phase position. The Magnetaktuatorik 27 includes a magnetic coil 28, not shown, by means of which a magnetic field can be generated, which passes through the coupling elements 23, 24, 25, 26 of the coupling unit 20. For the arrangement of the magnetic coil 28, the Magnetaktuatorik 27 comprises a yoke member 29 fixed to a not shown engine block of the internal combustion engine is connected. The yoke element 29 forms the stator 21 of the coupling unit 20.

The yoke element 29 is formed in half-section U-shaped. The magnet coil 28 is arranged in an inner space spanned by the yoke element 29. An opening of the yoke element 29 is directed in the direction of the rotor 22. The inner space spanned by the yoke element 29 extends annularly around the main axis of rotation 15. The magnet coil 28 has a coil winding which is arranged in the inner space spanned by the yoke element 29. The coil winding extends in relation to the main axis of rotation 15 in the circumferential direction. The coil axis of the magnet coil 28 is oriented coaxially with the main axis of rotation 15. By means of an energization of the magnetic coil 28, a magnetic field can be generated, which extends in the region of the magnetic coil 28 substantially in the yoke element 29.

The coupling elements 23, 24, 25, 26 are made of a magnetizable material. The coupling elements 23, 24, 25, 26 of the coupling unit 20 are magnetically coupled together. The magnetic force by means of which the phase position is adjustable causes between the coupling elements 23, 24, 25, 26 an attractive force. The braking force of the coupling unit 20 thus depends directly on the magnetic force. The magnetic force in turn is proportional to the magnetic flux which passes through the coupling elements 23, 24, 25, 26 of the coupling unit 20. The coupling elements 23, 24, 25, 26 are designed as Flußleitelemente, i. they are made of a magnetically soft material. The coupling elements 23, 24, 25, 26 are thus provided only for guiding the magnetic flux. They do not generate their own magnetic field.

To set a defined Notlaufphasenlage the adjusting device comprises a setting unit 30. The setting unit 30 is independent of the Magnetaktuatorik 27. The setting unit 30, the phase position between the drive unit 16 and the output unit 17 regardless of a functionality of the Magnetaktuatorik 27 adjust. The adjustment unit 30 is designed as a self-sufficient unit that can adjust the camshaft 10 independently of an external power supply.

The adjusting unit 30 comprises two mutually adjustable magnetic elements 31, 32, by means of which the magnetic force acting on the coupling elements 23, 24, 25, 26, can be mechanically changed. Furthermore, the setting unit 30 comprises a permanent magnet 33 which generates a magnetic field independently of the magnetic actuator 27 whose magnetic flux passes through the coupling elements 23, 24, 25, 26 and the magnetic elements 31, 32. The permanent magnet 33 is integrated in the yoke element 29. The magnetic field generated by the permanent magnet 33 is provided in a fail-safe operating mode and in a normal operating mode for adjusting the braking force provided by the coupling unit 20. The magnetic flux which is generated only by the permanent magnet 33 in the fail-safe operating mode is changed in the normal operating mode by means of the magnetic actuator 27.

For guiding the magnetic fields that can be generated by the permanent magnet 33 and the magnetic actuator 27, the adjusting device has a magnetic flux guide unit 34, which is formed by means of the adjusting gear 11, the phase adjusting unit 18 and the setting unit 30. The entire magnetic flux guide unit 34 is formed by means of magnetizable materials. The magnetic flux generated by the magnetic field is described by magnetic field lines 41, which emanate from the permanent magnet 33 and the Magnetaktuatorik 27. The magnetic field lines 41 are always formed as closed field lines. The magnetic flux guide unit 34 provides the magnetic flux with reduced air resistance relative to air. The magnetic field lines 41 influenced by the magnetic flux guide unit 34 run within the magnetizable material. The magnetic flux guide unit 34 is magnetically completely closable, i. the magnetic field lines 41 influenced by the magnetic flux guide unit 34 run almost completely within the magnetizable material.

In an operating state in which the magnetic field is generated only by the permanent magnet 33, the magnetic field lines 41 start from the permanent magnet 33. In an operating state in which the magnetic field is generated jointly by the permanent magnet 33 and the Magnetaktuatorik 27, a part of the magnetic field lines 41 is also from the permanent magnet 33 from. The magnetic flux described below is therefore to be understood as a part of a total magnetic flux that can be generated by the Magnetaktuatorik 27 and the permanent magnet 33. In principle, further magnetic field lines may exist which extend outside the magnetic flux guide unit 34 in partial regions.

The magnetic field lines 41 generated by the permanent magnet 33 pass through the phase adjustment unit 18, the adjusting mechanism 11 and the adjusting unit 30. Starting from the permanent magnet 33, the magnetic flux first passes through the yoke element 29. The coupling element 23 directly adjoins the yoke element 29, as a result of which the magnetic flux is passed from the yoke element 29 in the coupling element 23. Starting from the coupling element 23, the magnetic flux is through the coupling element 25 passed into the adjusting element 13. The magnetic flux then passes through the two magnetic elements 31, 32 of the setting unit 30. The magnetic element 32 directly adjoins the rotor 22 of the coupling unit 20, through whose radially inner portion the magnetic flux is conducted into the coupling element 26. Starting from the coupling element 26, the magnetic flux is conducted through the coupling element 24, which directly adjoins the yoke element 29. The yoke element 29 in turn conducts the magnetic flux to the permanent magnet 33, whereby the circle of the magnetic flux is completely closed.

The stator 21, whose yoke element 29 thus forms part of the magnetic flux guide unit 34, is thus partially associated with the magnetic flux guide unit 34. Furthermore, the magnetic flux guide unit 34 is associated with the adjusting gear element 12 of the adjusting gear 11. In addition, the two magnetic elements 31, 32 of the setting unit 30 form part of the magnetic flux guide unit 34. Furthermore, the rotor 22 of the coupling unit 20 is partially associated with the magnetic flux guide unit 34. In addition, the four coupling elements 23, 24, 25, 26 of the magnetic flux guide 34 are assigned.

The coupling elements 23, 25 always have a contact independently of an operating state of the coupling unit 20. The portion of the rotor 22, which forms the coupling element 25 is slidably mounted relative to the first Verstellgetriebeelement 12. The rotor 22 and the first adjusting gear element 12 are magnetically connected to one another in the region of the coupling element 25. The adjusting gear element 12 forms the first magnetic element 31 of the setting unit 30. The magnetic element 31 and the magnetic element 32 are also magnetically connected to each other via a common contact surface. The magnetic element 32 is slidably mounted on the rotor 22 and is thus magnetically connected to the portion of the rotor 22 which forms the coupling element 26. The coupling elements 24, 26 in turn always have a contact independent of an operating state of the coupling unit 20. The magnetic flux guide unit 34 is thus magnetically closed in an operating state in which the two magnetic elements 31, 32 have a contact area greater than zero. The magnetic resistance of the magnetic flux guide unit 34 is adjustable via the common contact surface of the magnetic elements 31, 32 by means of the setting unit 30. The magnetic elements 31, 32 can be completely separated from each other, ie by means of the magnetic elements 31, 32 is also an interruption of the magnetic flux through the magnetic elements 31, 32 adjustable.

The coupling unit 20 and the magnetic elements 31, 32 are magnetically arranged in series with respect to the magnetic field lines 41. The two magnetic elements 31, 32 are magnetically arranged in series with respect to the magnetic field lines 41. The magnetic field lines pass successively through the coupling elements 23, 25, the two magnetic elements 31, 32 and the coupling elements 24, 26. The magnetic elements 31, 32 are formed as Magnetflussleitelemente. They are made of a magnetically soft material. The magnetic field generated by the permanent magnet 33 has a magnetic flux, which is defined by means of the magnetic elements 31, 32, passed through the setting unit 30. The adjusting element 12 is arranged magnetically in series via the coupling elements 23, 24 of the stator 21 and the coupling elements 25, 26 of the rotor 22 with respect to the magnetic elements 31, 32. Along the magnetic field lines 41, the coupling elements 23, 24 of the stator 21 by means of the Verstellgetriebeelements 12 and the magnetic elements 31, 32 are connected to each other magnetic.

To adjust the magnetic force, the setting unit 30 comprises an adjusting mechanism 35, which shifts the two magnetic elements 31, 32 against each other in the fail-safe operating mode. The adjusting mechanism 35 is coupled to the two adjusting gear elements 12, 13. It shifts the two magnetic elements 31, 32 against each other when the defined by the Verstellgetriebeelemente 12, 13 phase position changes. The size of the contact surface of the two magnetic elements 31, 32 can be changed by means of the adjusting mechanism 35 of the adjusting unit 30. The setting unit 30 adjusts the size of the contact surface depending on the phase position.

The two magnetic elements 31, 32 are partially wedge-shaped. The first magnetic element 31 comprises a contact surface region 36, which is tilted by an angle of approximately 25 degrees against an adjustment direction of the magnetic elements 31, 32. Furthermore, the magnetic element 31 comprises a contact surface region 37, which is oriented along the adjustment direction. The second magnetic element 32 likewise comprises a contact surface region 38 tilted against the adjustment direction and a contact surface region 39 oriented along the adjustment direction. The contact surface regions 36, 38 and the contact surface regions 37, 39 can each be brought into contact with one another. The contact surface of the two magnetic elements is formed as an area in which the magnetic elements 31, 32, touch, ie, a region in which the contact surface areas 36, 37 with the contact surface areas 38, 39 are partially or completely in contact. To set the emergency running phase position, the setting unit 30 changes the size of the contact surface. The size of the contact surface is adjustable by means of the adjusting mechanism 35 of the setting unit 30. To change the contact surface displaces the adjustment mechanism 35, the two magnetic elements 31, 32 against each other. The adjustment of the magnetic elements 31, 32 is oriented parallel to the main axis of rotation 15 of the adjusting device.

In order to adjust the two magnetic elements 31, 32, the adjustment mechanism 35 of the setting unit 30 has an actuating element 40. The actuating element 40 is coupled along its actuating direction 45 to the magnetic element 32. The actuating element 40 is designed as an axially displaceable pressure pin, which is mounted against the second adjusting element 13. The actuator 40 passes through the first Verstellgetriebeelement 12, against which the actuating element 40 is mounted axially displaceable. The actuator 40 is passed through the planet gears 19. It is slidingly mounted within the first Verstellgetriebeelements 12. The actuating direction 45, along which the actuating element 40 is displaceable, is oriented parallel to the main axis of rotation 15 of the adjusting device.

Furthermore, the adjusting mechanism 35 of the setting unit 30 comprises a thermocouple 42, by means of which the emergency running phase position is set temperature-dependent. The thermocouple 42 has a geometry provided for adjusting the phase position, which changes as a function of an operating temperature. The Notlaufphasenlage is adjusted by means of the temperature dependence of the geometry of the thermocouple 42. The thermocouple 42 forms an inclined surface 43, by means of which a change in the phase position is converted into an axial adjustment of the actuating element 40. The thermocouple 42 is fixedly connected to the second Verstellgetriebeelement 13. The inclined surface 43 is arranged on the second adjusting element 13.

The inclined surface 43 forms a Verstellrampe 44, the height decreases along an adjustment of the phase angle in the direction of late. The axially displaceably mounted actuating element 40 is coupled along its actuating direction 45 to the thermocouple 42. During an adjustment of the phase position, the adjusting gear elements 12, 13 rotate relative to one another, whereby the actuating element 40 moves on the inclined surface 43 formed by means of the thermocouple 42. The thermocouple 42 converts a change in the phase position into a linear movement of the actuating element 40.

By the circumferentially directed method of the actuator 40 on the inclined surface 43, the thermocouple 42 moves the actuator 40 in the axial direction. When adjusting the phase position from early to late moves the Inclined surface 43, the actuator 40 axially in the direction of the second Verstellgetriebeelements 13. In an adjustment of the phase position from late in the early direction, the inclined surface 43 moves the actuator 40 axially in the direction of the first Verstellgetriebeelements 12th

The thermocouple 42 is formed as a bimetallic element. The bimetallic element is formed as a bimetallic sheet whose main extension direction is directed in the circumferential direction. The thermocouple 42 has different shapes at different operating temperatures. The thermocouple 42 changes a circumferentially directed slope of the inclined surface 43 as a function of the operating temperature. To form the inclined surface 43, the thermocouple 42 formed as a bimetallic sheet is fastened at one end to the second adjusting gear element 13. The end at which the thermocouple 42 is connected to the second Verstellgetriebeelement 13 is directed in the direction of the adjustment of the phase angle to early. In a cold operating condition, the thermocouple 42 is deformed in the direction of the first Verstellgetriebeelements 12. The inclined surface 43 has a large pitch in the cold operating state. A distance between an end remote from the fixed end of the thermocouple 42 end and the second Verstellgetriebeelement 13 is maximum in the cold operating condition. The distance decreases as the operating temperature becomes higher. In a warm operating condition, the thermocouple 42 forms a flatter ramp. The thermocouple 42 changes an adjustment range of the actuating element 40, by which the actuating element 40 is displaced at a maximum adjustment of the phase position, as a function of the operating temperature. It gets smaller as the operating temperature gets higher. In a cold operating state, the thermocouple 42 partially or completely disconnects the contact surface regions 36, 37, 38, 39 of the magnetic elements 31, 32 of the adjustment unit 30 depending on the phase position. In the very warm operating state, the magnetic elements 31, 32 are always completely connected to each other.

In the hot operating state, the thermocouple 42 does not move the actuator 40 axially in the direction of the first Verstellgetriebeelements 12. The thermocouple 42 is characterized for different operating temperatures, in which the Internal combustion engine can be operated, each before a defined Notlaufphasenwinkel.

A change in the axial position of the actuating element 40 causes a displacement of the magnetic elements 31, 32 against each other. The inclined surface 43 of the setting unit 30 thus sets a change in the phase position in an adjustment of the magnetic elements 31, 32 to. By adjusting the magnetic elements 31, 32, the size of the contact surface between the two magnetic elements 31, 32 changes. By means of the inclined surface 43 is thus a magnetic resistance adjustable, which opposes the flux flow to the magnetic flux. About the by means of the thermocouple 42 mutually adjustable magnetic elements 31, 32 of the magnetic flux, which passes through the coupling elements 23, 24, 25, 26 of the coupling unit 20, and thus the magnetic force between the coupling elements 23, 24, 25, 26 mechanically directly changeable. Due to the thermocouple 42, the mechanically set magnetic resistance of the magnetic flux conducting unit 34 is temperature-dependent.

If the phase position is adjusted in the direction of late, the contact area between the two magnetic elements 31, 32 is large. The magnetic resistance, which opposes the magnetic flux provided by the permanent magnet 33, is thus small. Thus, the magnetic flux that passes through the coupling elements 23, 24, 25, 26 of the coupling unit 20, large, whereby the provided by the Koppeteinheit 20 braking force is also large. The setting unit 30 thus sets a braking force by which the phase position is adjusted in the direction of early (see. FIG. 1 ).

If the phase position is adjusted in the direction of early, the contact area between the two magnetic elements 31, 32 is small. The magnetic resistance, which opposes the magnetic flux provided by the permanent magnet 33, is thus large. Thus, the magnetic flux, which passes through the coupling elements 23, 24, 25, 26 of the coupling unit 20, small, whereby the braking force provided by the coupling unit 20 is also small. The setting unit 30 thus sets a braking force by which the phase position is adjusted in the direction of late (see. FIG. 3 ).

Since the two coupling elements 23, 25 and the two coupling elements 24, 26 of the coupling unit 20 are only actuated together, form the four coupling elements 23, 24, 25, 26, a coupling unit 20. The setting unit 30 can change the frictional force of the coupling unit 20 by means of the magnetic elements 31, 32. The setting unit 30 adjusts the emergency running phasing by changing the braking force of the coupling unit 20 of the phase adjusting unit 18. The coupling unit 20 is provided for the phase adjustment unit 18 and the adjustment unit 30. The adjusting device has only one coupling unit 20.

In an operating state in which a speed is adjusted for the third Verstellgetriebeelement 14, which is equal to a speed of the first Verstellgetriebeelements 12, a currently set phase position between the crankshaft and the camshaft 10 is kept constant. In an operating state in which the rotational speed of the third adjusting gear element 14 is greater than the rotational speed of the first adjusting gear element 12, the phase angle of the camshaft 10 is adjusted in the direction of late. In an operating state in which the speed of the third Verstellgetriebeelements 14 is smaller than the rotational speed of the first Verstellgetriebeelements 12, the phase angle of the camshaft 10 is moved toward early.

To adjust the phase position in the late direction, the coupling unit 20 is opened. During operation, the camshaft 10 has a drag torque, for example caused by bearing points of the camshaft 10, by means of which the camshaft 10 is adjusted in the direction of retardation. If the coupling unit 20 is open, the rotational speed of the third Verstellgetriebeelements 14 by the drag torque of the camshaft 10 will be greater than the speed of the first Verstellgetriebeelements 12. The camshaft 10 is thus adjusted in the direction of late.

To maintain the current phase position, the phase adjustment unit 18 sets a magnetic field strength by means of the magnetic actuator 27 whose magnetic force causes precisely one required braking force in the coupling unit 20. The braking force is adjusted to a value at which the speed of the third Verstellgetriebeelements 14 is equal to the speed of the first Verstellgetriebeelements 12 (see. FIG. 2 ).

To adjust the phase in the direction early, the coupling unit 20 is closed. The speed of the third Verstellgetriebeelements 14 is smaller than the rotational speed of the first Verstellgetriebeelements 12. Thus, the speed of the second Verstellgetriebeelements 13 is greater than the rotational speed of the first Verstellgetriebeelements 12, whereby the camshaft 10 is moved in the direction early.

In the fail-safe operating mode, the setting unit 30 mechanically controls the phase angle of the camshaft 10 to the emergency running phase position. To set the emergency running phase position, the setting unit 30 changes the braking force of the coupling unit 20 of the phase adjustment unit 18. The emergency phase position always corresponds to a basic phase position adapted to the operating temperature due to the thermocouple 42. In the fail-safe operating mode, the setting unit 30 automatically regulates the phase position mechanically to the emergency running phase position one. In the fail-safe operating mode, the magnetic actuator 27 of the phase adjustment unit 18 is de-energized. The basic phase position is set via the setting unit 30, which sets by means of the magnetic elements 31, 32 a necessary for setting the corresponding braking force magnetic flux.

The adjusting unit 30 controls the phase position by means of the magnetic elements 31, 32. If the phase position, starting from the base phase position, is displaced towards the beginning, the magnetic elements 31, 32 cause a reduction of the magnetic flux through the coupling elements 23, 24, 25, 26, whereby the braking force the coupling unit 20 is reduced. The adjustment unit 30 mechanically adjusts the phase position in the direction of late. If the phase position is adjusted starting from the base phase position in the direction of late, the magnetic elements 31, 32 cause an increase in the magnetic flux through the coupling elements 23, 24, 25, 26, whereby the braking force of the coupling unit 20 is increased. The adjustment unit 30 mechanically adjusts the phase position in the direction of early. The adjustment unit 30 regulates the phase position independently, i. regardless of an external control or regulation, resistant to the emergency running phasing.

In the normal operating mode, at medium temperatures, the setting unit 30 mechanically adjusts the phase angle of the camshaft 10 initially to the basic phase position. The basic phase position corresponds to the Notlaufphasenlage, which is set when the magnetic actuator 27, a magnetic field is set to zero. The phase adjustment unit 18 adjusts the phase position by means of the Magnetaktuatorik 27, starting from the set by means of the setting unit 30 basic phase position. In order to adjust the phase position in the direction of early or late, starting from the basic phase position, a magnetic field not equal to zero is set for the magnetic actuator 27 of the phase adjustment unit 18. In order to adjust the phase position early starting from the emergency running phase position, a magnetic field is set by means of the magnetic actuator 27, which amplifies the magnetic field of the permanent magnet 33. To adjust the phase position starting from the Notlaufphasenlage in the late direction, a magnetic field is set by the Magnetaktuatorik 27, which attenuates the magnetic field of the permanent magnet 33.

In the normal operating mode, the coupling unit 20, which is provided in the fail-safe operating mode for setting the Notlaufphasenlage, provided for adjusting an adjustment angle. To adjust the adjustment angle, the magnetic actuator 27 of the phase adjustment unit 18 changes the braking force of the coupling unit 20 by changing the magnetic flux passing through the coupling elements 23, 24, 25, 26. The adjusting mechanism 35, which in the fail-safe operating mode, the two magnetic elements 31, 32 against each other, attempts in the normal operating mode, the phase angles by displacement of the two magnetic elements 31, 32 against each other to a constant value. A current phase position is set in the normal operating mode independently of a control or regulation of the adjustment mechanism of the Magnetaktuatorik 27.

In an operating state in which the emergency running phase position is set and the magnetic actuator 27 amplifies the magnetic field, first of all the magnetic flux which passes through the coupling elements 23, 24, 25, 26 of the coupling unit 20 increases. The increased magnetic flux causes an increase in the braking force of the coupling unit 20, whereby the phase position is adjusted toward early. The adjustment of the phase position in the direction early causes the adjustment mechanism 35 to reduce the contact area between the two magnetic elements 31, 32. The reduction of the contact area increases the magnetic resistance, which precludes the magnetic flux, and the braking force provided by the coupling unit 20 is reduced again. As soon as the braking force is reduced again by the adjustment of the phase position to a value at which the phase position is kept constant, the phase position with respect to the Notlaufphasenlage is adjusted towards early.

An adjustment of the phase position in the direction of late takes place analogously. In an operating state in which the Notlaufphasenlage is set and the Magnetaktuatorik 27 reduces the magnetic field, first reduces the magnetic flux, which passes through the coupling elements 23, 24, 25, 26 of the coupling unit 20. The reduced magnetic flux causes a reduction in the braking force of the coupling unit 20, whereby the phase position is adjusted in the late direction. The adjustment of the phase position in the direction of late causes the adjustment mechanism 35 increases the contact area between the two magnetic elements 31, 32. By increasing the contact area, the magnetic resistance that opposes the magnetic flux decreases, and the braking force provided by the coupling unit 20 is increased again. As soon as the braking force is increased again by the adjustment of the phase position to a value at which the phase position is kept constant, the phase position with respect to the Notlaufphasenlage is adjusted towards late.

Irrespective of an adjustment direction of the phase position, the adjustment angle by which the phase angle is deflected by means of the magnetic actuator 27 from the basic phase position set by the setting unit 30 depends directly on the magnetic field generated by the magnetic actuator 27. The magnetic field generated by the Magnetaktuatorik 27 defines only the adjustment angle, ie the deflection from the basic phase position. The adjusting mechanism 35 of the adjusting unit 30 thus regulates the basic phase position mechanically dependent on the adjustable by means of the phase adjustment 18 adjustment angle ..

The thermocouple 42 of the adjustment mechanism 35, which adjusts the emergency running phase position and thus the basic phase position dependent on temperature, shifts in the cold operating state, the basic phase position in the direction early. In the warm operating state, the basic phase position is delayed in the direction of late.

The adjusting device comprises two stops, not shown, by means of which the entire angular range over which the phase angle is adjustable is limited. The phase angle is adjustable over a range of zero degrees to 140 degrees. Zero degrees corresponds to a maximum adjustment of the phase position in the direction of late. 140 degrees corresponds to a maximum adjustment of the phase position in the direction of early.

In the warm operating state, the adjusting mechanism 35 sets for the contact surface of the magnetic elements 31, 32 on average a larger value than in the cold operating state. A caused by the Magnetaktuatorik 27 change of the magnetic field thus causes a stronger change in the adjustment angle in the warm operating state than in the cold operating state.

Claims (11)

1. Camshaft adjusting device for an internal combustion engine, having a phase adjustment unit (18) which has a coupling unit (20) for adjusting a phase position in a normal operating mode which is adapted to apply a braking force to an adjustment gear element (14), and also having a setting unit (30) which is adapted to set a defined emergency phase position in a failsafe operating mode,
   characterised in that
   the setting unit (30) is adapted, at least in the failsafe operating mode, to steadily change the braking force of the coupling unit (20) of the phase adjustment unit (18) in dependence upon the phase position.
2. Adjusting device according to claim 1,
   characterised in that
   the coupling unit (20) is adapted to set the emergency phase position in a failsafe operating mode and to set an angle adjustment in a normal operating mode.
3. Adjusting device according to claim 2,
   characterised in that
   the phase adjustment unit (18) has a magnetic actuator system (27) which is adapted, for the purpose of setting the angle adjustment, to set the braking force of the coupling unit (20) magnetically.
4. Adjusting device at least according to claim 2,
   characterised in that
   the setting unit (30) has an adjusting mechanism (35) which is adapted to mechanically regulate the phase position with respect to the emergency phase position and / or the angle adjustment.
5. Adjusting device according to one of the preceding claims, characterised in that
   the setting unit (30) has at least one permanent magnet (33) which generates a magnetic field provided to actuate the coupling unit (20).
6. Adjusting device according to one of the preceding claims,
   characterised in that
   the setting unit (30) has at least two magnet elements (31, 32) adjustable relative to each other which are adapted to mechanically change a magnetic force to set the braking force.
7. Adjusting device according to one of the preceding claims,
   characterised in that
   the coupling unit (20) has a fixed-location stator (21) and at least a first coupling element (23, 24) which is axially displaceably attached to the stator (21).
8. Adjusting device according to claim 7,
   characterised in that
   the coupling unit (20) has at least one further coupling element (24) attached to the stator (21), said coupling element (24) being arranged spaced apart from the first coupling element (23).
9. Adjusting device according to claim 7 or 8,
   characterised in that
   the at least one coupling element (23, 24) is connected in an axially displaceable manner to the stator (21).
10. Adjusting device at least according to claim 7,
    characterised in that
    the at least one coupling element (23, 34) is produced from a magnetisable material.
11. Adjusting device according to one of the preceding claims,
    characterised in that
    the coupling unit (20) has an axially fixedly arranged rotor (22) which is produced in at least one sub-element from a magnetisable material.

Images