DE19800232A1 - Actuating unit for friction clutch of motor vehicle - Google Patents

Abstract

The unit (10) includes a disconnection arrangement (32), which is controlled by a pressure medium power cylinder unit (14) in a positioning servo unit. The cylinder unit is operated by a control valve (42), connected to a pressure source (51), as a function of a reference variable, representing a desired position, and an actual variable, representing the axial position of the disconnection arrangement. The cylinder unit comprises a ring cylinder (16), which is concentric to the coupling axis (A) and exerts pressure on the disconnection arrangement coaxially to the coupling axis. The control valve comprises two valve elements and, depending on the difference between the reference and actual variables, is adjustable between a first position, in which the ring cylinder is connected with the pressure source, and a second position, in which the ring cylinder is connected to a pressure balance opening (70). The reference and actual variables are each represented by the position in the valve housing of one of the two valve elements. The difference variable is represented by the relative position of the two variables.

Description

The invention relates to an actuating device for in the drive train of a motor vehicle, in particular a commercial motor vehicle, between one Internal combustion engine and a gearbox arranged a bell Friction clutch comprising a substantially coaxial Friction clutch movable release bearing arrangement for actuation of the Rei Exercise clutch and a positioning servo with one on the Release bearing arrangement acting pressure medium power cylinder arrangement, the via a control valve connected to a pressure medium source depending on a reference variable representing a target position and one the axial one Position of the release bearing assembly representing actual size is actuated.

Such an actuator is for example from DE 33 21 578 C2 known. The known actuator has a vacuum Servo power amplifier as a positioning servo arrangement. The kind of Vacuum brake booster built with servo power booster a pneumatic power cylinder and a control valve integrally formed and arranged outside the bell housing. Two working chambers of the Pneumatic power cylinders are guided by an axially movable piston and an elastic membrane separated. One as a vacuum chamber trained working chamber is connected to an intake manifold system engine connected. The other serving as the tax chamber Working chamber is by means of the control valve either with the vacuum mer or connectable to the atmosphere via a pressure compensation opening. The vacuum servo amplifier is actuated via an a valve rod of the control valve striking control rod, which via a cam driven by an electric motor is axially displaceable. An axial  Shifting the control rod causes the control valve to switch, such that the piston follows the movement of the control rod with increased force. The Movement of the piston acts on you via a hydraulic master cylinder connected to the master cylinder, arranged outside the bell housing Neten slave cylinder, which in turn on one of the release bearing assembly assigned release fork acts. An emergency actuation of the clutch at idle internal combustion engine, i.e. lack of negative pressure, is thereby possible that the control rod directly over the valve body of the control valve can act on the piston.

The control valve has a valve body with an elastic Valve seat interacts. A connection channel is provided in the valve seat, through which the connection between the control chamber and the ambient air takes place unless the valve body is pressed against the elastic valve seat to close the connection channel through the valve body. A Another connecting channel connects the control chamber with the sub pressure chamber.

Furthermore, an actuator of the type mentioned is known which a pneumatic power cylinder as a pressure medium power cylinder arrangement having. The actuating device is designed as a pneumatic power cylinder, a hydraulic slave cylinder and integral control valve Unit attached to the outside of the bell housing. The piston of the pneumatics Power cylinder is on the piston of the hydraulic slave cylinder forming rod member attached, and the rod member is with a Connected plunger that extends into the bell housing and one of the Release bearing assembly attacks associated release fork. To the hydraulic slave cylinder is a clutch pedal operated master cylinder and a control input of the control valve connected. The control valve controls the depending on the hydraulic pressure at the control input Supply of compressed air to the pneumatic power cylinder or the discharge of Air from the pneumatic power cylinder such that a predetermined, by  a compression spring arrangement certain hydraulic pressure at the control input sets. The hydraulic slave cylinder serves as a measuring cylinder the position of the rod element and thus indirectly the position of the Release bearing arrangement detected. When the master cylinder is actuated, over the hydraulic slave cylinder serving as the measuring cylinder directly the rod element and thus exerted on the release bearing arrangement, in addition to the actuation forces of the pneumatic power cylinder due to the Supply of compressed air in these.

It is contemplated an actuator of the type mentioned To bring to market in which the pressure medium power cylinder arrangement is arranged within the bell housing. One possible variant draws is characterized in that the pressure medium power cylinder arrangement for exercise a force coaxial to the clutch axis on the off rear bearing arrangement is formed. For example, that the pressure medium power cylinder arrangement to the clutch axis in essentially comprises concentric pressure medium ring cylinder.

With such an arrangement, a control valve could in principle type described above with a serving as a measuring cylinder hydrauli rule slave cylinder are used, of which when the Control valve forces are exerted on the release bearing assembly. Here would be disadvantageous that in the case of one to exercise one to clutch Axis essentially coaxial force on the release bearing assembly trained pressure medium power cylinder arrangement by the measuring cylinder Tipping moments are exerted on the release bearing assembly, if not also the measuring cylinder for exerting the coupling axis essentially coaxial forces formed on the release bearing assembly, for example as a measuring ring cylinder which is essentially concentric with the coupling axis is trained. Such a measuring ring cylinder would have the disadvantage that in the case of leaks in the hydraulic measuring cylinder an exchange of Measuring cylinder necessary to detach the bell from the internal combustion engine  would do. On the other hand, one used, for example, the side of the Pressure medium power cylinder arrangement arranged measuring cylinders, so condition the ent then exerted on the release bearing arrangement speaking higher mechanical effort to these tilting moments record or compensate.

In contrast, an object of the present invention is an actuation device of the type mentioned with within the bell housing to provide arranged pressure medium power cylinder arrangement, in which Sides of the control valve (and one possibly associated with the control valve Measuring arrangement or the like) no considerable forces, in particular tilting forces, on the release bearing arrangement (except via the pressure medium power cylinder the arrangement by means of a pressure medium supplied).

Another object of the present invention is an actuator to provide device of the type mentioned, which is a simplified Maintenance (regardless of the arrangement of the pressure medium power cylinder arrangement opening inside or outside the bell housing) of the control valve or components associated with this.

In order to solve at least one of these tasks, according to the invention suggested that the control valve be one between a first, the pressure connecting medium-power cylinder arrangement with the pressure medium source Control state and a second, the pressure medium power cylinder arrangement with adjustable control state connecting a pressure compensation opening Valve arrangement includes, which depends on one of the actual size and the Füh size assigned between the two control states which is switchable, the valve arrangement two relative to each other and comprises movable valve elements relative to a valve housing and the Command variable through the position of a first of the two valve elements and the actual size by the position of a second of the two valve elements relative  is represented to the valve housing and the difference size by the position of the two valve elements is represented relative to one another.

The inventive design of the control valve with two valve elements, whose positions each have a separate, the control state of the control valve represent determining size, enables a decoupling between the "Actual size side" of the positioning servo arrangement on the one hand and the "Füh tion size side "of the positioning servo arrangement on the other hand such that at Change of the management variable from the "management variable side" of the Positioning servo arrangement no considerable variable forces on the Release bearing arrangement except via the pressure medium power cylinder arrangement be exercised by means of a pressure medium supplied. From the "leadership then the size side "of the positioning servo arrangement will not be considerable tilting moments exerted on the release bearing assembly. Mechanical effort to absorb or compensate for tipping forces can thus be omitted, whereby the actuating device according to the invention is cheaper to produce.

Since the actual size and the reference size are each determined by the position of a own valve element is represented, is an uncomplicated coupling of the control valve to a reference variable transmitter unit on the one hand and to one Actual size encoder unit on the other hand possible. The control valve can thus be trained friendly, for example, such that it without large Exchangeable effort.

The valve arrangement can be in one depending on the difference third control state to be adjustable, in which the pressure medium power cylinder arrangement is preferably essentially sealed pressure medium, so at the same time neither with the pressure medium source nor with the pressure compensation opening connected is. The third control state then becomes a specific position be assigned to the valve arrangement. The third tax state can, however also characterized in that the valve arrangement alternately the  first control state and the position arranged to the second control state occupies so that the pressure medium power cylinder arrangement is not pressure medium is tightly closed.

It is proposed that the control valve have a first signal connection Receiving a command signal indicating the command variable in particular from a clutch pedal assembly and a second signal connector to Receiving an actual value signal indicating the actual size from one of the Disengaging bearing arrangement associated encoder element arrangement. Before the command signal and the actual value signal then act in each case regardless of the other signal on exactly one valve element two valve elements directly, namely the command signal to the first Valve element and the actual value signal on the second valve element. That the Signals act directly on exactly one valve element, does not rule out that the signals via intermediate components to the respective valve element Act. The term "act directly" is only used to distinguish from "indirect" effects, especially of the guidance signal on the second Valve element on the positioning servo arrangement such that namely by corresponding switching of the control valve between the control states is achieved by means of the pressure medium power cylinder arrangement that the actual size is set according to the specification by the management variable and himself accordingly the position of the actual size second valve element changes.

The actual value signal can be a pressure, a volume, a Force, a path, an angle, a current or a voltage represented hydraulic, pneumatic, mechanical or electrical Be signal, the second signal connection, if necessary, converter means are assigned to convert the actual value signal into the actual quantity. Is a to convert pneumatic or hydraulic actual value signal, so the Converter means comprise a piston, in particular spring-loaded, which  preferably coupled or connectable to the second valve element, in particular is integral with this.

It is proposed that the positioning servo assembly be a mechanical one Position control arrangement with a the position of the release bearing arrangement directly or indirectly capturing, mechanically coupled or coupling encompasses donor element. In this connection it is preferred that the transmitter element acts on the second valve element, in particular with this is motion-linked or motion-linkable. The second Valve element can have an integral with this coupling if necessary element with the release bearing assembly or the release bearing assembly page the pressure medium power cylinder arrangement is preferably essentially rigid be coupled or connectable. But it is also possible that the second Valve element over a preferably rigid with this coupled, if necessary with this integral, against the release bearing arrangement or the release bearing arrangement side of the pressure medium power cylinder the arrangement biased or biased coupling element with this is coupled or can be coupled.

The command signal can be a pressure, in particular a volume, a force, a path, an angle, a current, a Voltage, or a light intensity represented hydraulic, pneumati act, electrical or optical signal, the first Signal connection, if necessary, converter means for converting the guide signals are assigned to the reference variable. It is preferably at the command signal around a pneumatic or hydraulic, top preferably a hydraulic command signal. In this context it is proposed that the converter means for converting the pneumatic or hydraulic guide signal, especially a spring-loaded one Include piston, which is preferably coupled to the first valve element or can be coupled, in particular is integral with it.  

The valve arrangement can be in addition to the first and the second valve element a relative to the valve housing and / or relative to the two said valve elements include movable auxiliary valve element that with the first and / or second valve element cooperates to at least to provide one of the control states.

After an advantageous embodiment of the actuation according to the invention Direction points from the elements - first valve element and second Valve element - a at least one section forming a control edge on that with at least three pressure medium openings in the other valve element and in the valve housing, in particular a pressure medium opening in the other Valve element and two pressure medium openings in the valve housing, together acts to in at least one relative position of the two valve elements to each other when one valve element moves relative to the other Valve element in one direction by moving at least one Control edge on at least one of the pressure medium openings, in particular the Pressure medium opening in the other valve element, a first pressure medium ver binding within the control valve, especially the pressure medium connection between the pressure medium source and the pressure medium power cylinder arrangement, to interrupt or establish another pressure medium connection within the control valve, in particular the pressure medium connection between the pressure compensation opening and the pressure medium power cylinder arrangement deliver or interrupt. This training is preferably based on a cooperating with the first and / or second valve element, Auxiliary valve element movable relative to the valve housing is dispensed with. Reason in addition, both valve elements can each have at least one control have edge forming portion; but it can only do either first or the second valve element have such a section.

One of the valve elements - first valve element and second valve element - can have at least one in particular pin-like engagement section, the in an associated slot-like recess of the other valve element  engages, the recess by an at least one stop forming the edge of the recess, possibly with two recesses stops limiting both ends, is limited to limit the Movement range of the two valve elements relative to each other. If so Engagement section or the recess has no further function it is generally irrelevant to the function of the control valve whether the first Valve element or the second valve element has the engagement portion.

It is particularly preferred that the second valve element is coupled to the first valve element such that the second Valve element in a basic state of the actuator without Clutch actuation, the first valve element in a preferably any Starting position taking clutch wear into account relative to the second Valve element stops at a defined at the beginning of a clutch actuation Provide response of the actuator and / or ins special clutch wear-induced free travel at least small too hold, preferably to avoid. For this purpose, the two valve elements have cooperating stops in the starting position. As The at least one engagement section and the stop preferably serve recess border delimiting the recess.

It is particularly preferred that the control valve (un depending on the other design features) in a basic state the actuating device without clutch actuation the pressure connecting the same opening with the pressure medium power cylinder arrangement Assumes tax status. Takes place with a as a pneumatic power cylinder arrangement trained trained pressure medium power cylinder ventilation of Cylinder arrangement via the pressure equalization opening to the atmosphere, see above there is ambient pressure in the basic state of the actuating device within the cylinder assembly, so that unwanted pressure changes within the cylinder arrangement due to external influences (e.g. Temperature) are excluded.  

It is proposed that the first and the second valve element in one Recess of the valve housing are mounted, one of the valve elements rotatable about a valve axis and the other valve element either the valve axis is rotatable or displaceable along the valve axis, wherein the actual size and the reference size either through a rotary position of the respective valve element or one of these sizes by a rotational position and the other of these sizes by an axial position of each Valve element are represented.

A valve element can have at least two of the two valve elements have separate pressure medium passage openings, one of which Passage opening in at least one position of this valve element relative to the valve housing with a first pressure medium passage opening of the Valve housing is in pressure medium passage connection and the other Passage opening in at least one position of this valve element relative to the valve housing with a second pressure medium passage opening Valve housing is in pressure medium passage connection. In the other The valve element is then at least one further pressure medium passage opening provided, a pressure medium passage opening thereof in at least a position of this (the other) valve element relative to the valve housing with a third pressure medium passage opening of the valve housing in Pressure fluid passage connection is.

To implement the control states of the control valve, it is proposed that in a first relative position or in a first relative position range of the two valve elements to each other the one further pressure medium passage opening tion in the other valve element with one of the at least two separate Pressure medium passage openings in a valve element in pressure medium through lass connection stands, and that in a second relative position or in one second relative position range of the two valve elements to one another further pressure medium passage opening in the other valve element with a other of the at least two separate pressure medium passage openings  is in a valve element in pressure medium passage connection. So that can be achieved that in at least one position range of the two Valve elements relative to each other and relative to the valve housing assigned pressure medium passage openings in the valve housing and in the two valve elements a pressure medium connection between the pressure medium source and the pressure medium power cylinder assembly is made, and that in at least one other position range of the two valve elements relative to each other and relative to the valve housing via assigned pressure medium Through openings in the valve housing and in the two valve elements Pressure medium connection between the pressure medium power cylinder arrangement and the pressure compensation opening is made.

One further pressure medium passage opening is preferably located in the other Valve element in a third relative position or in a third relative Position range of the two valve elements to each other with none of the at least two separate pressure medium passage openings in one Valve element in pressure medium passage connection. This can be achieved be that in at least one position of the two valve elements relative to each other and relative to the valve housing neither a pressure medium connection between the pressure medium power cylinder arrangement and the pressure medium source, another pressure medium connection between the pressure medium power cylinder arrangement voltage, and the pressure compensation opening is made.

With regard to the closer structure of the control valve, it is proposed that of the two valve elements one valve element one to the valve axis has coaxial ring section, which is the other valve element of the two Valve elements encloses at least partially radially outside. Furthermore, the other valve element of the two valve elements one to the valve axis have coaxial ring portion of an inner portion of the valve housing it can enclose at least in regions radially on the outside. The inside section can have at least one pressure medium passage opening.

Alternatively or additionally, the ring section coaxial with the valve axis can also be used  of one valve element and / or the ring section coaxial to the valve axis of the other valve element and / or the one valve element radially outside enclosing the recess of the valve housing at least partially delimiting valve housing wall at least one respective pressure medium Have passage opening, said pressure medium passage opening interactions for realizing the valve control states and accordingly in position, shape and size are coordinated.

As already mentioned, the valve elements, in particular the first and the second valve element, in a recess of the valve housing by one Valve axis can be rotatably supported, the actual size and the reference size are represented by rotational positions of the respective valve element.

It was also mentioned that the first valve element and second valve element - one, in particular the second valve element, can have one ring section coaxial to the valve axis, the other Valve element of the two valve elements at least in regions radially outside encloses. In this context, it is particularly preferred that the radially outward from an inner circumferential surface delimiting the recess Valve housing surrounding ring section of at least one valve element two extending in the circumferential direction, against each other in the circumferential direction offset from each other by a respective section of the ring section separate and radially inward and radially outward openings as Pressure medium passage openings that at least in the valve housing two bores opening into the recess, in particular radially directed are provided as pressure medium passage openings, the mouth openings of the holes are offset in the circumferential direction and one in at least one rotational position of one valve element cover at least partially another of the breakthroughs and that in the other Valve element at least one connecting channel as a pressure medium passage opening tion, in particular a through hole is provided, which in little at least one relative rotational position of the two valve elements to each other  the breakthrough is open, especially by the two mouth openings the through hole of at least one of the openings are partially covered.

For this purpose, it is further proposed as particularly advantageous that in each case exactly three holes, exactly three breakthroughs and exactly one Connection channel, in particular a radially extending passage bore are provided, wherein in at least one rotational position range two valve elements relative to one another and relative to the valve housing two of the holes, two of the breakthroughs and the connecting channel one Pressure medium connection between the pressure medium source and the pressure medium Power cylinder assembly is made and in at least one other Rotational position range of the two valve elements relative to each other and relative to the valve housing via two of the holes, two of the openings and the Connection channel a pressure medium connection between the pressure medium Power cylinder assembly and the pressure compensation opening is made.

The sections of the ring section that separate the openings are preferably dimensioned such that in at least one relative rotation position of the two valve elements to each other and / or in at least one Rotational position of one valve element relative to the valve housing at least a channel opening, in particular the opening of the through hole in the other valve element and / or at least one of the orifices of the holes in the valve housing by a particular one Control edge forming portion of the ring portion is closed.

The latter measures can be easily achieved be that in at least one rotational position of the two valve elements relative to each other and relative to the valve housing neither a pressure medium connection between the pressure medium power cylinder arrangement and the pressure medium source, another pressure medium connection between the pressure medium power cylinder arrangement voltage and the pressure compensation opening is made. Even without an additional  This auxiliary valve element can be moved relative to the housing thus three control valves by means of the first and second valve elements stands, namely "pressure medium connection between the pressure medium source and the pressure medium power cylinder arrangement "," pressure medium connection between the Pressure medium power cylinder arrangement and the "pressure compensation opening" and "in essential fluid-tight closure of the pressure medium power cylinder arrangement realization ".

The orifices of the three holes in the valve housing are preferred arranged with the same circumferential angle at a distance from each other and preferably each cover an equally large circumferential angle range. It is correspondingly the case for the three openings in the ring section of one Valve element preferred that these each have the same size Cover angle range and with the same circumferential angle at a distance are arranged from each other. The orifices are preferably the three holes and correspondingly the three openings in the axial direction essentially not offset against each other.

Of the three bores, one preferably follows the pressure equalization opening assigned hole, a hole assigned to the pressure medium source and a bore associated with the pressure medium power cylinder arrangement in one predetermined sense of rotation one another, with the actuator in the basic state supply device an opening of the through hole in the first Valve element of the bore associated with the pressure compensation opening, for example opposite, a portion of the ring portion forming a control edge of the second valve element in the direction of rotation compared to that of the pressure compensation Opening associated offset, but this is closely adjacent, and wherein for actuating the clutch, the first valve element opposite the Rotational position of the basic state is rotatable in the sense of rotation, in particular at most up to a rotational position in which the mouth of the Through hole of the hole associated with the pressure medium source, for example opposite.  

The recess receiving the valve elements can be preferably transverse passage extending to the direction of movement of the release bearing arrangement bore in the valve housing, at one end the first Valve element is accessible, in particular protrudes, and at the other The second valve element is accessible, in particular protrudes. In this connection is proposed as particularly preferred that a end section protruding from the through hole in the valve housing second valve element a rigidly coupled bracket as a coupling element who carries on the release bearing assembly or the release bearing assembly side of the pressure medium power cylinder arrangement attacks, in particular by spring means engaging the bracket and the valve housing, preferably comprising a leg spring arranged around the end section, against this is biased, or with this form-fitting (for example by means of an elongated hole, into which an engagement section of the bracket engages) is coupled, so that the Bracket is forcibly taken. A linear movement of the release bearing arrangement or the release bearing arrangement side of the pressure medium The power cylinder arrangement is then in a rotary movement of the bracket second valve element can be implemented.

Provided converter means for converting a pneumatic or hydraulic Guide signal are provided, the spring-loaded piston Converter means part of a separate cylinder compared to the valve elements Be piston arrangement, the piston preferably in one direction is movable, which extends substantially transversely to the valve axis, and wherein a linear movement of the piston via one on the first valve element attacking coupling arrangement, in particular toggle lever arrangement, in a Rotational movement of the first valve element can be implemented.

As already mentioned, the first and the second valve element can alternatively be in be recessed in the valve housing, one of the Valve elements rotatable about a valve axis and the other valve element is displaceable along the valve axis, the actual size and the  Command size one size by a rotation position and the other size is represented by an axial position of the respective valve element. This Training is particularly advantageous in that the release bearing arrangement a linear movement when engaging and disengaging that simply moves in a corresponding linear movement of the one representing the actual size displaceable valve element can be implemented. Is a clutch pedal assembly provided, so a clutch pedal rotation of the clutch Pedals simply tapped and in a corresponding rotary movement of the Reference variable representing rotatable valve element are implemented. In this case, it would be particularly useful to have the control valve on the clutch to arrange the pedal. The control valve can also easily in the Bell housing, in particular on the pressure medium power cylinder arrangement be arranged. Regardless of the location of the control valve can the sliding valve element also to represent the reference variable and the rotatable valve element serve to represent the actual size.

The proposed control valve can be made comparatively short be so that it is in the case of an arrangement on the pressure medium power cylinder arrangement with its valve axis parallel to the movement direction of the pressure medium power cylinder arrangement can be arranged. Serves the displaceable valve element to represent the actual size, see above can be dispensed with any force redirection, so that the constructive Effort is reduced.

As preferred, a valve element has a control edge that is associated with assigned pressure medium openings in the other valve element and in Valve housing interacts, because of the translational and a rotational mobility component comprising relative mobility a simple specification of a characteristic curve of the two valve elements is possible the relationship between the degree of clutch pedal actuation on the one hand and Specifies target position or command variable on the other hand. A corresponding Characteristic curve can be realized, for example, in that  Valve element an elongated hole having a corresponding course as Has pressure medium passage opening, which with associated pressure medium Through openings with compared to the expansion of the elongated hole clearly reduced dimensions interacts. A slot that delimits the slot Section of the valve element and / or a said other passage Opening-limiting section of the respective valve element can be used as Control edge can be understood. Is the switch between the Control states by moving such a control edge past one assigned pressure medium opening, this moving past requires only one comparatively low actuation force, so that the control valve through high low lateral force.

With regard to the design of the control valve or the valve elements proposed that the first valve element coaxial to the valve axis Has ring section, the second valve element at least in regions encloses radially outside.

Furthermore, the valve element which can be displaced along the valve axis, ins especially the first valve element, against rotation around the valve axis be secured. The valve element rotatable about the valve axis, ins special the second valve element, can be moved along the Valve axis must be secured. Through the anti-rotation or displacement protection achieved that the rotational position of the two valve elements relative to each other only by the rotational position of the rotatable valve element and the displacement po sition of the two valve elements relative to each other only by the displacement po sition of the sliding valve element is determined so that for a well defined control behavior of the control valve is provided.

One of the two valve elements, in particular the first valve element, can at least two against each other in the circumferential direction and / or in the axial direction staggered holes, especially bores, as a pressure medium passage opening have openings. The other valve element then preferably has  at least one with the holes for realizing the valve control states cooperating slot as a pressure medium passage opening that extends both in the circumferential direction and in the axial direction and preferred point obliquely to an (imaginary) axially parallel generatrix of this valve elements runs.

It is proposed that the control valve, especially the valve housing or / and the first valve element or / and the second valve element, Has pressure medium guide means for a Druckmitteldurchlaßver bond between each other in pairs assigned pressure fluid passage on the one hand in the valve housing and on the other hand in one of the two Valve elements regardless of the position of this valve element relative to Take care of the valve housing. In this case, the tax status of the Control valve essentially only through the pressure medium passage openings or control edges of the two valve elements, and the pressure medium Through openings of the valve housing only serve to supply pressure medium to the valve and further to the pressure medium power cylinder arrangement or Drain pressure medium from the pressure medium power cylinder arrangement via the Control valve.

With regard to the design of the pressure medium guide means, there are various Options. For example, the pressure medium guide means at least one extending in the axial direction and / or in the circumferential direction Pressure medium guide recess in adjoining surfaces sections of the valve housing, the first valve element and the second Include valve element. The pressure medium guide recess (or otherwise expressed: the part having the pressure medium guide recess) then usually a respective pressure medium passage opening (in the area of Pressure medium guide recess), the pressure medium Guide recess with the pressure medium passage opening in pairs assigned pressure medium passage opening regardless of the position of the respective valve element is in pressure medium passage connection. Further  can the pressure medium guide means at least one in the control valve trained, of at least two elements of the valve housing, the first Valve element and second valve element at least partially limited Include interior space in which the pressure medium Through openings regardless of the position of the respective valve element flow out.

The control valve according to the invention can be comparatively few Pressure fluid passage openings get along. So one draws before drafted embodiment of the control valve characterized in that in at least a position range of the two valve elements relative to one another and relative to the valve housing via exactly two pressure medium openings in the Valve housing, exactly one pressure medium passage opening in the first valve element and exactly one pressure medium passage opening in the second valve element a pressure medium connection between the pressure medium source and the Pressure medium power cylinder assembly is made and in at least one other position range of the two valve elements relative to each other and relative to the valve housing via exactly two pressure medium through-openings in the valve housing, exactly one pressure medium passage opening in the first Valve element and exactly one pressure medium passage opening in the second Valve element a pressure medium connection between the pressure medium power cylinder the arrangement and the pressure compensation opening is made, wherein basically the pressure equalization opening with one of the pressure medium passages openings in the valve housing can coincide.

It is proposed that the control valve have biasing means which preload at least one of the two valve elements in one direction, preferably in a direction towards a basic state of actuation device without clutch actuation corresponding position.

The biasing means act on the second, which represents the actual size Valve element, depending on the coupling with the release bearing arrangement  if necessary, keep the preload low so as not to cause any significant Apply lateral forces to the release bearing assembly. Such opening credits means are preferred for the translational (displaceable) valve element provided, especially if this with a hydraulic or pneumatic piston is integral or in one piece.

The second valve element can at least one from outside the Ventilge Have accessible section, or it can be with this Valve element connected, led out of the valve housing Coupling element may be provided, the accessible section or Coupling element serves the second valve element with the release bearing arrangement or the release bearing arrangement side of the pressure medium power cylinder the arrangement to couple motion. Accordingly, the first Valve element at least one accessible from outside the valve housing Liche section, or it can be with this valve element connected coupling element led out of the valve housing be provided, the accessible section or the coupling element serves to move the first valve element according to the command variable. This is a simple mechanical coupling of the valve in question elements to the release bearing arrangement or to a clutch pedal arrangement tion or the like possible.

The first and the second valve element can be inserted into one another Cylinder body or hollow cylinder body, in particular circular cylinder body or circular cylinder hollow body. The valve housing can be a interior and a the recess that receives the valve elements facing outer housing part, wherein the inner housing part preferably a cylinder section, in particular a circular cylinder section has, which can be inserted into the valve elements.

The valve element which can be displaced along the valve axis can be secured against rotation Means for example in the form of a preferably to the valve axis  have coaxial pin section, optionally polygonal pin section, the in an associated, cross-sectional opening of a housing section, in particular the inner housing part, is insertable. The Anti-rotation means can also be tongue and groove means on the valve element and an adjacent housing portion.

To limit the range of motion of the two valve elements relative to each other or / and to hold the first valve element in the output position when the actuator assumes the basic state one of the two valve elements has a recess, in particular an axially and circumferential direction, possibly obliquely to an axis parallel Surface line of the valve element, have an elongated hole into which the preferably serving as a coupling element engaging section of the other Valve element engages. The course of the recess is preferably at the Adapted the course of the elongated hole serving as a pressure medium passage opening, on the one hand a defined one regardless of possible clutch wear Provide response of the actuator and / or ins special clutch wear-induced free travel at least small too hold, and on the other hand one required to implement the control states Chen range of movement of the valve elements relative to each other.

To achieve a high level of operational reliability of the control valve, you can abutting surface sections of the valve housing, the first and the second valve element can be designed as sealing and / or sliding surfaces, or / and sealing elements can act sealingly between them be. This applies to all proposed variants of the invention Control valve.

The general rule is that the release direction of the pressure medium power cylinder arrangement and the disengagement direction of the friction clutch any orientation can have each other. This does not only apply if the pressure medium Power cylinder arrangement arranged outside the bell housing and  is attached to the gear housing, for example. Especially in the event that the pressure medium power cylinder arrangement within the bell housing is arranged, but it is often useful if the direction of disengagement Pressure medium power cylinder arrangement and the disengagement direction of the friction coupling are substantially parallel to each other, preferably the Coupling axis and the power cylinder assembly axis essentially collapse.

The valve axis and the power cylinder arrangement axis can in principle be oriented towards each other as required and do not need a point in common to have. However, it is preferred that the valve axis and the power cylinder arrangement Axis are substantially parallel to each other or in projection a plane substantially parallel to both axes to each other in the we are considerably orthogonal.

The measures described above and preferred training of the Control valve or the valve arrangement according to all variants described contribute individually and also together to the fact that the control valve is compact, has a high level of functional reliability and is inexpensive can be produced. The control valve can be completely inside the bell housing or at least partially arranged within the bell housing, and is preferably when connected to the internal combustion engine and the transmission Bell housing accessible from the outside, especially removable. The actuator supply device can then be easily serviced and, if necessary, repaired without that the generally formed by a portion of a gear housing Housing bell must be released from the internal combustion engine. The Control valve can be integrally formed with the pressure medium power cylinder arrangement det be, but it is preferred that the control valve as a separate unit is in particular detachably attached to the pressure medium power cylinder arrangement.

With a view to being particularly easy to maintain, is considered particularly preferably proposed that a control valve comprising  Control valve assembly opposite one of the pressure medium power cylinder Arrangement comprising power cylinder assembly in a related to the Power cylinder arrangement axis is offset in the radial direction and on one radially outer portion of the power cylinder assembly is releasably attached. In In this context, it is particularly advantageous if the control valve Unit effective after loosening any between the two units Fastening and / or coupling means, which preferably consist of at least one radial direction essentially corresponding to the radial direction are accessible from the power cylinder assembly essentially in the radial direction is removable. The resulting maintenance Friendliness comes both inside and outside the case bell arranged control valves for carrying.

The pressure medium can be pneumatic or hydraulic Act leverage. It is particularly preferred that the pressure medium is pneumatic pressure medium, wherein the pressure medium source is preferably a pressure source supplying a higher pressure than ambient pressure.

The invention also relates to a control valve, in particular for an actuation Device according to one of the preceding claims, the invention at least a portion of the control valve features described above Actuating device according to the invention.

The invention is illustrated below with reference to the figures Exemplary embodiments explained in more detail.

Fig. 1 shows a schematic, partially sectioned view of an actuating device according to the invention with a pressure medium power cylinder arrangement in the form of a pressure medium ring cylinder, in particular pneumatic ring cylinder.

Fig. 2 shows a perspective view of a pressure medium power cylinder arrangement with a flanged control valve of a further actuating device according to the invention.

Fig. 3 shows the control valve and a portion of the pressure medium power cylinder arrangement of Fig. 2 in a perspective partially sectioned view with a different viewing direction.

Fig. 4 shows a section through the control valve and a portion of the pressure medium ring cylinder, in particular pneumatic Ringzylin the pressure medium power cylinder arrangement of FIG. 2 along line IV-IV in Fig. 5th

Fig. 5 shows a section through the control valve and a portion of the pressurized fluid power cylinder assembly of Fig. 2 along the line VV in Fig. 4.

FIG. 6 shows a section through the control valve of FIG. 2 along line VI-VI in FIG. 4.

Fig. 7 shows the components of another exemplary embodiment shows an exploded view of a control valve of the invention for an inventive actuator.

Fig. 8 shows a first perspective side view of the assembled control valve of Fig. 7.

Fig. 9 shows a second perspective side view of the assembled control valve of Fig. 8 with a different viewing direction.

Fig. 10 shows a first longitudinal section through the control valve of Fig. 8 and 9 according to line XX in Fig. 13.

Fig. 11 shows a second longitudinal section through the control valve of Fig. 8 and 9 according to line XI-XI in Fig. 13.

FIG. 12 shows a first cross section through the control valve of FIGS. 8 and 9 along line XII-XII in FIG. 11.

FIG. 13 shows a second cross section through the control valve of FIGS. 8 and 9 along line XIII-XIII in FIG. 11.

Fig. 14 shows a third cross section through the control valve of Fig. 8 and 9 according to line XIV-XIV in Fig. 11.

Fig. 15 shows in Figs. 15a to 15f cross sections through the control valve of Figs. 8 and 9 for different positions of the valve elements relative to each other and relative to the valve housing to explain the operation of the control valve when changing the command variable in one direction (corresponding to a clutch actuation to disengage the clutch).

Fig. 16 shows in Figs. 16a to 16e show cross sections through the control of Fig. 8 and 9 relative to each other for different positions of the valve elements and relative to the valve housing when changing the command variable in the opposite direction valve (corresponding to a clutch control for a coupling of the clutch) .

Fig. 17 to Fig. 24 are respectively a schematic longitudinal sectional view and a schematic cross section to show through a respective variant of a control valve with a rotatable and displaceable cash valve member to illustrate various ways of mapping between the valve elements on the one hand and the reference variable and the actual size on the other.

Fig. 25 to Fig. 30 show six further embodiments of a control valve according to the invention.

Fig. 31 shows in a perspective partially cutaway view of a further embodiment of an inventive control valve which corresponds in its basic operation of the control valve of the embodiment of Fig. 2 to 6.

Fig. 32 shows in Fig. 32a a section through the control valve of Fig. 31 only partially according to the section shown there in a basic state position without clutch actuation and in Fig. 32b the section in an actuation position for clutch actuation.

In Fig. 1, an actuating device 10 according to the invention for a in the drive train of a motor vehicle between an internal combustion engine and a transmission in a bell housing 12 arranged friction clutch, here a pressed clutch, is shown. The actuating device 10 comprises a pressure medium power cylinder arrangement 14 , here a pneumatic power cylinder arrangement, which is also referred to below as an actuating cylinder unit. The actuating cylinder construction unit 14 comprises a pressure medium ring cylinder, here a pneumatic Ri 97666 00070 552 001000280000000200012000285919755500040 0002019800232 00004 97547ngzy cylinder 16 , which is formed by an annular cylindrical recess 18 in a stationary body part 20 and a pneumatic annular piston element 22 . The pneumatic ring piston element 22 is biased by spring means 24 in the direction of the clutch, not shown (in Fig. 1 to the left) and carries sealing rings 26 for sealing the ring cylinder space of the pneumatic ring cylinder 16th

The pneumatic ring cylinder 16 and the pneumatic ring piston element 22 are arranged coaxially with a clutch axis A. The body part 20 has an axial bore through which the transmission input shaft 28 extends coaxially to the clutch axis A.

A ring section 30 of the pneumatic ring piston element 22 at the clutch-side end of the ring piston element forms a release ring 30 of a release bearing arrangement 32 , which furthermore enables a release ring 34 which is rotatable relative to the release ring 30 and rotates with the clutch, and enables the relative rotation between the two release rings 30 and 34 chendes ball bearing 36 includes. The release bearing arrangement acts upon actuation of the actuating device in a known manner, in particular via diaphragm spring tongues on the clutch, in order to disengage it to interrupt the flow of force between the transmission and the internal combustion engine.

The actuating cylinder assembly 14 carries a control valve assembly 40 releasably attached to the actuating cylinder assembly, which comprises a control valve 42 shown only schematically in FIG. 1. The control valve assembly 40 is arranged such that it protrudes through an associated opening 44 in the Ge housing bell 12 beyond the outside of the bell and can be removed when the housing bell connected to the internal combustion engine and the gearbox.

The control valve 42 is connected via a pneumatic line 46 within the control valve assembly 40 , via a pneumatic connection 48 to the section of the control valve assembly projecting beyond the outer side of the bell housing 12 and via a further pneumatic line 50 with a pneumatic source 51 . The control valve 42 is also connected via a line 52 within the control valve assembly 40 , a connection 54 to the section of the control valve assembly 40 projecting beyond the outside of the housing bell 12, and via a further line 56 to a control signal transmitter unit 60 . When the guide signal generator unit 60 is in the present case a clutch pedal assembly 60 with a clutch pedal 62 , which is designed to provide a guide signal in the form of a hydraulic signal's via line 56 , the connection 54 and the line 52 to the control valve 42nd transferred to. The lines 52 and 56 are accordingly hydraulic lines that are connected via the connection 54 designed as a hydraulic connection.

The control valve 42 is also connected to the annular cylinder space of the pneumatic annular cylinder 16 via a pneumatic line 64 within the control valve assembly 40 and a pneumatic line 66 within the actuating cylinder assembly 14 . Furthermore, the control valve 42 is connected via a pneumatic line 68 within the control valve assembly 40 to a pressure compensation opening 70 in the clutch-side surface of the control valve assembly.

The current axial position of the release bearing arrangement 32 is fed to the control valve 42 via mechanical coupling elements 72 and 74 in the form of a mechanical actual value signal representing a path, as is shown schematically by the dashed connection 76 within the control valve assembly 40 . For this purpose, the rod-like coupling element 74 protruding from the control valve assembly 40 is motion-coupled to a valve element of a valve arrangement comprising two valve elements. Of the two valve elements, a first valve element is assigned to the guide signaling unit 60 , and a second (already mentioned) valve element is assigned to the release bearing arrangement and is coupled in motion via the coupling elements 72 and 74 with the latter with regard to the axial movement of the release bearing arrangement. The two relative to each other and movably mounted relative to the valve elements Steuerventilbaueinheit 40 serve to realize various control states of the control valve 42nd For preferred embodiments of the control valve 42 , reference is made to the following exemplary embodiments.

The control valve 42 switches in dependence on the guide signal output by the guide signaling unit 60 , which specifies a desired axial position of the release bearing arrangement 32 , and on the actual value signal indicating the current axial position of the release bearing arrangement 32, between three control states. In a first control state, a pneumatic connection between the pneumatic ring cylinder 16 and the pneumatic source 51 is established via the control valve 42 , so that the pneumatic ring cylinder from the pneumatic source 52 is supplied with pneumatic medium, here compressed air, and the pneumatic annular piston element 22 accordingly from the The recess moves out towards the clutch. In a second control state of the control valve 42 is a pneumatic connection between the pneumatic ring cylinder 16 and the pressure balance port 70 is made via the control valve 42 so that the disengaged pneumatic annular piston member 22 by the urging force of the clutch main spring, z. B. a diaphragm spring or the like, engages again in the recess 18 , the compressed air located in the ring cylinder space of the pneumatic ring cylinder 16 flowing out of the pressure compensation opening 70 . In a third control state, the ring cylinder chamber of the pneumatic ring cylinder 16 is essentially pneumatically sealed, so that the pneumatic ring piston element 22 maintains its current axial position.

The control valve 42 , with its valve elements, the pneumatic power cylinder arrangement 14 , the coupling element 72 which represents a transmitter element for the actual value signal, and the coupling element 74 form a mechanical position control arrangement which, by appropriately switching between the three control states, changes the axial position of the release bearing arrangement 32 to that by the Guide signal from the command signal generator unit 60 sets the specified position. For this purpose, the current position of the release bearing arrangement 42 is represented as the actual variable by the position of the second valve element and the target position of the release bearing arrangement is represented as the reference variable by the position of the first valve element. The actual variable and the reference variable are assigned a differential variable, which is represented by the position of the first and the second valve element relative to one another and assumes the value zero if the actual axial position of the release bearing arrangement 32 corresponds to the desired position.

The following are further exemplary embodiments of the invention Actuator or individual components according to the invention Actuators explained. Here, when describing the respective embodiment for equivalent or analog components where appropriate, the same reference numerals as for the previously described embodiments used. Here, each because only on the differences to the one or already described Embodiments discussed and otherwise expressly on the previous description of the other embodiment (s) reference taken. To differentiate the embodiments, the reference  characters by small letters in alphabetical order (without a and c) featured.

Fig. 2 shows an actuating cylinder assembly 14 b of an actuating device according to the invention, which also comprises a pneumatic ring cylinder 16 b with a pneumatic ring piston element 22 b. The cylinder space of the pneumatic ring cylinder 16 b is sealed by at least one effective sealing ring 27 b between the pneumatic ring piston element 22 b and the body part 20 b of the actuating cylinder assembly 14 b. B at the Betätigungszylinderbaueinheit 14 Steuerventilbaueinheit 40 is flanged b releasable. The control valve assembly 40 b comprises a control valve 42 b with a valve housing 90 b, in which two valve elements, namely a first valve element 92 b and a second valve element 94 b are movably mounted relative to one another and relative to the valve housing 90 b. The control valve 42 b has a pneumatic connection 48 b to which the pneumatic source 51 b is connected via the pneumatic line 50 b. Furthermore, the control valve has a hydraulic connection 54 b, to which the clutch pedal arrangement 60 b is connected via the hydraulic line 56 b.

In the exemplary embodiment in FIGS . 2 to 6, the first valve element 92 b and the second valve element 94 b can be rotated about a valve axis B ′ to represent the actual axial position of the release bearing arrangement or of the pneumatic annular piston element 22 b by the rotational position of the second valve element 94 b and to represent the target position of the release bearing arrangement or the pneumatic annular piston element 22 b by the rotary setting of the first valve element 92 b.

The valve housing 90 b has a circular cylindrical through hole 180 b, which extends coaxially to the valve axis B ′ across the valve housing 90 b, is open on both sides and the two valve elements, that is to say the first valve element 92 b and the second valve element 94 b records. The control states of the control valve are realized solely by the first valve element 92 b and the second valve element 94 b.

In the through hole 180 b three radial bores 182 b, 184 b and 186 b open in a common plane orthogonal to the valve axis B ′, between the radial bore 182 b and the radial bore 184 b, between the radial bore 184 b and the radial bore 186 b and between the radial bore 186 b and the radial bore 182 b, based in each case on the valve axis B ', there is the same circumferential angle distance and the three bores each cover an equally large circumferential angle range. In the view according to Fig. 5 follow the three radial bores along the periphery of the through hole 180 b in the clockwise direction in the order of 182 b, 184 b and 186 b each other.

The radial bore 182 b creates a connection between the interior of the through hole 180 b and the environment and serves as the pressure compensation opening 70 b of the control valve. The radial bore 184 b is part of the pneumatic connection 48 b and thus establishes a pneumatic connection between the interior of the through bore 180 b and the pneumatic source 51 b via the pneumatic line 50 b. At the radial bore 186 b there are bores 188 b in the body part 20 b of the actuating cylinder assembly 14 b, via which a connection is established between the interior of the through bore 180 b and the cylinder space of the pneumatic ring cylinder 60 b (see FIG. 5). (The first valve element 92 b has not yet been taken into account in these considerations.) The intersecting bores 190 b and 192 b are closed to the outside of the body part 20 b by pressed-in locking balls 194 b.

The first valve element 92 b has a circular cylindrical main section 198 b which is accommodated in the through bore 180 b and coaxial to the valve axis B ', on which there is also a circular cylindrical coil which is coaxial with the valve axis B' and from the through bore 180 b, on the one (left, Fig. 4) side projecting pin portion 200 b of the first valve element 92 a connects. The main section 198 b has a through bore 202 b radially directed to the valve axis B ′, which lies in the same plane perpendicular to the valve axis B ′ as the radial bore 182 b, 184 b and 186 b.

The main section 198 b of the first valve element 92 b in the through-hole 180 b is of a the remaining annular space between the main section 198 b and the inner circumferential surface of the through-hole 180 b filling, to the valve axis B 'coaxial circular cylindrical ring section 204 b of the second valve element 94 b surround. At the ring portion 204 b connects in the direction of the pin portion 200 b opposite end of the through hole 180 b is still arranged in the through hole 180 b, and in the radius of this substantially corresponding circular wall portion of the second valve element 94 b, to which in turn, a protruding from the through hole 180 b, to the valve axis B 'coaxial circular cylindrical pin section 208 b closes. Thus, b on one side of the through hole 180 is the journal portion 200 b of the first valve element from and on the other side of the through hole 180 b is therefore the journal portion 208 b of the second valve member before.

The ring section 204 b of the second valve element has three slot-like passage recesses 210 b, 212 b and 214 b, which can be referred to as slots or openings, each of which extends in the circumferential direction with respect to the valve axis B 'and in the same or thogonal to the valve axis B' Level as the radial holes 182 b, 184 b and 186 b and the through hole 202 b. The three passage recesses 210 b, 212 b and 214 b, referred to briefly below as openings, each cover an equally large circumferential angle and the circumferential angular distances between the opening 210 b and the opening 212 b, between the opening 212 b and the opening 214 b and between the Breakthrough 214 b and breakthrough 210 b are the same size. The circumferential angle covered by the openings is approximately 95 °, whereas the distance circumferential angle between the openings is approximately 25 °. The radial bores 182 b, 184 b, 186 b, the through hole 202 b and the openings 210 b, 212 b and 214 b each extend in the axial direction over the same axial area of the control valve, as can be seen clearly in FIG. 4.

In the outer circumferential surface of the ring portion 204 b of the second valve element 94 b are on both sides of the openings 210 b, 212 b, 214 b sealing rings 216 b, and in the main portion 198 b of the first valve element 92 b is opposite to the through hole 202 b in the direction of Pin portion 200 b offset sealing ring 218 b provided. These sealing rings 216 b and 218 b serve to the radial bores 182 b, 184 b and 186 b, the through hole 202 b and the apertures 210 b, 212 b and 214 b comprehensive axial region of the through hole 280 b b between the sealing rings 216 to the seal both open ends of the through hole 180 b pneumatically. Further, in Fig. 4 recognizable, but not provided designated snap rings, the second valve member 94 b in the through hole 180b and the first valve member 92 b with its main portion 198 b in the interior of the ring portion 104 b of the second valve member 94 b secure.

The two valve elements 92 b and 94 b can only be rotated relative to one another to a limited extent, since on the axial end face of the main section 198 b of the first valve element 92 b opposite the pin section 200 b, two pins 220 b are provided which are radially offset with respect to the valve axis B ′ and which a respective, longitudinally extending recess 222 of a circular arc b in the wall portion 206 b of the second valve member 94 b engage (see. Fig. 4 and Fig. 6). Due to the dimensioning of the recesses 222 b, the two valve elements can be rotated relative to one another over an angular range of approximately 75 ° to 80 °.

The two valve elements 92 b and 94 b are formed with the openings 210 b, 212 b and 214 b, with the through hole 202 b, the pins 220 b and the recesses 222 b in relation to one another in such a way that the through hole 202 b is in any possible relative rotational position of the two valve elements communicates on one side with the opening 214 b and on the other side either with the opening 210 b or with the opening 212 b or through a section 224 b forming a closure and control section between the two Breakthroughs 210 b and 212 b is closed pneumatically. The breakthrough 210 b is always in connection with the pressure compensation opening 70 b, the breakthrough 212 b is constantly connected via the bore 184 b to the pressure medium source 51 b, and the breakthrough 214 b is constantly in via the bore 186 b Connection to the cylinder chamber of the pneumatic ring cylinder 16 b.

The second valve element 94 b is coupled to the pneumatic ring piston element 22 b in such a way that each axial position (based on the coupling axis) of the pneumatic ring piston element 22 b and thus the release bearing arrangement is assigned exactly one rotational position of the second valve element 94 b. For this purpose, at the journal portion 208 b of the second Ventilele ments 94 b a bracket 226 b rotatably mounted, the section through a the pin 208 b surrounding the bracket 226 b and the valve body 90 b acting (see. Fig. 2 and Fig. 4 ) Coil or leg spring 228 b is biased against the flange-like end section 162 b of the pneumatic ring piston element 22 b. The bracket 226 b engages on the side of the end portion 162 b remote from the clutch.

On the pin portion 208 b, a lever 230 b is rotatably attached, which forms a two-part toggle lever with a piston rod 232 b of a cylinder-piston arrangement 234 b. The cylinder-piston arrangement 234 b is a hydraulic slave cylinder which is connected to the clutch pedal arrangement 60 b via the connection 94 b and the hydraulic line 56 b. A piston 236 b on the piston rod 232 b is biased by a helical compression spring 238 b in the sense of reducing the cylinder space of the hydraulic slave cylinder 234 b.

The hydraulic slave cylinder 234 b is designed with the valve housing 90 b as a structural unit.

The toggle lever arrangement comprising the lever 230 b and the piston rod 232 b serves to convert a displacement movement of the piston 236 b into a rotary movement of the first valve element 92 b. Each displacement position of the piston 236 b is assigned exactly one rotational position of the first valve element 92 b.

In a basic position of the control valve, in which the clutch pedal 92 b of the clutch pedal arrangement 60 b is not depressed and the pneumatic annular piston element 22 b is not disengaged, i.e. assumes its axial position furthest from the clutch, the opening of the through hole 200 b opposite the opening 214 b is in the main section 198 b of the first valve element 92 b is arranged approximately opposite the pressure equalization opening 70 b and the closure and control section 224 b is offset somewhat in relation to the pressure equalizing opening 70 b, in the clockwise direction with respect to FIG. 5, in the direction of the bore 184 b. The other opening of the through hole 202 b is opposite the opening 214 b, and is therefore not closed by the section 240 b separating the opening 214 b from the opening 212 b of the ring section 204 b of the second valve element 94 b. Thus, in the described basic state, there is a constant ventilation connection between the cylinder chamber of the pneumatic ring cylinder 16 b and the pressure compensation opening 70 b, namely via the bores 192 b, 190 b, 186 b, the opening 214 b, the through hole 202 b and the opening 210 b. The compressed air of the pneumatic source 91 b is retained by the closure and control section 225 b and the section 240 b of the ring section 204 b of the second valve element 94 b.

Now, when the driver presses the clutch pedal 62 b, the first valve element 92 b (which can also be referred to as the pedal travel unit) is rotated with the mouth opening previously opposite the ventilation opening 70 b, the through hole 202 b in the direction of the bore 184 b forming the compressed air inlet opening . Here, by passing over the control edge forming the closure and control section 224 b between the opening 210 b and the opening 212 b, the vent is first closed by the closure and control section 224 b closing the through hole 202 b, then the ventilation connection between the cylinder chamber of the pneumatic ring cylinder 16 b and the pneumatic source 51 b, namely via the hole 184 b, the opening 112 b, the through hole 202 b, and the holes 186 b, 188 b, 190 b and 192 b. If compressed air now flows into the cylinder chamber, the pneumatic annular piston element 22 b moves against the force of the diaphragm spring in the direction of the clutch. The second valve element (which can be designated as a disengagement path unit) follows the angle of rotation specified by the first valve element. During the supply of compressed air to the cylinder space of the pneumatic ring cylinder 16 b, an outflow of the supplied compressed air from the pressure compensation opening 70 b through the closure and control section 224 b and a breakthrough 214 b from the breakthrough 210 b separating section of the ring section 204 b of the second valve element 94 b prevented.

If the clutch pedal is held in the actuated position reached, the closure and control section 224 b closes the through hole 202 b in the main section 198 b of the first valve element 92 b again when the rotation angle predetermined by the first valve element is reached, so that the compressed air supply is interrupted, but also no vent connection between the cylinder chamber of the pneumatic ring cylinder 16 b and the pressure compensation opening 70 b is made. Then there is an equilibrium of forces between the on from the diaphragm spring to the pneumatic ring piston member 22 b applied force and that of the compressed air in the cylinder chamber of the pneumatic ring cylinder 16 b of the pneumatic annular piston element force b applied 22nd

If the clutch pedal 62 b is released again, the first valve element 92 b is rotated in the opposite direction due to the spring force exerted by the spring 238 b on the piston 236 b, so that the vent connection between the pressure compensation opening 70 b and the cylinder chamber of the pneumatics is now again provided -Ring cylinder 16 b is produced and the pneumatic ring piston element 22 b is pushed by the force of the diaphragm spring away from the clutch in the direction of the transmission with a corresponding rotation of the second valve element 94 b.

As the above statements make clear, in the embodiment described above with reference to FIGS. 2 to 6, the set position of the pneumatic annular piston element 22 b and thus the release bearing arrangement and the current actual position of the pneumatic annular piston element 22 b and so that the release bearing assembly represented by rotational positions of the first valve element 92 b and the second valve element 94 b. With its rotational position, the first valve element thus represents a reference variable and the second valve element re, with its rotational position, therefore represents an actual variable, on the basis of which the control valve switches between the control states generally indicated in connection with FIG. 1. The reference variable and the actual variable can be assigned a difference variable, which is represented by the relative rotational position of the two valve elements to one another.

To the relative rotatability of the two valve elements restricting recesses 222 b and pins 220 b has to be added that the arrangement is such that the second valve element 94 b entrains the first valve element 92 b when the "rest-rotational position" of the second valve element 94 b in the fully engaged state without clutch actuation changes over time due to increasing clutch wear. In the basic state of the actuation device without clutch actuation, the two valve elements always assume the same rotational position relative to one another (regardless of the wear state of the clutch), so that in the course of increasing clutch wear, only the rotational position of the two valve elements changes relative to the valve housing and an increasing free travel at the beginning pedal actuation is avoided. The two recesses 222 b each serve with one end as an end stop of the second valve element 94 , which takes the first valve element 92 b via the pins 220 b when coupling into the basic position or rest position determined by the state of the clutch.

A further exemplary embodiment of a control valve according to the invention, which could be provided in the actuating device of FIG. 1 within the control valve assembly, is shown in FIGS. 7 to 16. Fig. 7 shows the control valve 42 d in a perspective exploded view, which reveals all the essential components of the control valve. The control valve has a two-part valve housing 90 d with a first housing part 400 d and a second housing part 402 d. The first or outer housing part 400 d is designed as a circular cylindrical hollow body and has a recess 180 d delimited by a cylinder wall 404 d and at an axial end by an end wall 406 d. The recess 180 d serves to receive two valve elements 92 d and 94 d and a circular cylindrical inner portion 408 d of the second housing part 402 d, which in the assembled state closes the other axial end of the recess 180 d with an end wall 410 d. As can be seen in FIGS. 10 and 11, in the assembled state of the control valve between the circular cylindrical inner portion 408 d of the second housing part 402 d and the cylinder wall 404 d of the first housing part 400 d an annular cylindrical space is formed, in which the two valve elements 92 d and 94 d with a respective circular cylindrical wall section 412 d (first valve element 92 d) and 414 d (second valve element 94 d), respectively. As the inserted, wherein the cylinder wall 404 d of the wall portion 412 d of the first valve member 92 d radially surrounds the outside of the wall portion 412 d of the first valve member 92 d the wall portion 414 d of the second valve member 94 d radially surrounds the outside and the wall portion 414 d to Inner portion 408 d of the second housing part 402 d encloses radially on the outside. Between the circular cylindrical wall section 414 d of the ring-shaped second valve element 94 d and the inner section 408 d, an annular space 416 d serving as a pressure medium passage is formed, the function of which will still be discussed.

The first valve element 92 d can be displaced along the valve axis B ″ and is designed as a piston element of a cylinder-piston arrangement 234 d integral with the control valve. For this purpose, the first valve element 92 d has an end wall section 418 d which adjoins the circular-cylindrical wall section 412 d which is coaxial with the valve axis B '' and which extends orthogonally to the valve axis B '' and together with the end wall 406 d of the first housing part 400 d and the Cylinder wall 404 d of the first housing part 400 d limits a hydraulic slave cylinder 420 d which is connected via a hydraulic connection 54 d formed in the end wall 406 d and a hydraulic line (not shown) to the hydraulic master cylinder of a clutch pedal arrangement.

The first valve element 92 d is by means of a polygonal pin section which adjoins the end wall 418 d and is coaxial with the valve axis B ″ and surrounds radially on the outside from the wall section 412 and which fits into a cross-sectionally adapted opening 423 d in the inner section 408 d of the non-rotatable with the first housing part 400 d connected - for example screwed (not shown in the figures) - second housing part 402 d engages, secured against rotation relative to the valve housing 90 d. Between the first valve element 92 d and the second valve element 94 d, a helical spring 424 d enclosing the polygonal pin section 422 d is clamped, which prestresses the first valve element 92 d in the sense of a reduction in the volume of the slave cylinder 420 d and about the valve axis B '' rotatable second valve element 94 g holds in a predetermined axial position with abutment on the end wall 410 d of the second housing part 402 d. The second valve element 94 d is thus rotatable about the valve axis B '', but secured against displacement along the valve axis B '' due to the action of the spring 424 d.

To seal the hydraulic slave cylinder 420 d, the first valve element 92 d carries an O-ring 426 d. The inner section 408 d of the second housing part 402 d also carries a first and a second O-ring 428 d, which seal the annular space 416 d from the rest of the recess 180 d.

To implement the control states of the control valve mentioned in connection with FIG. 1, this has two openings in the cylinder wall 404 d of the first housing part 400 d, which serve as a pneumatic connection 48 d and pressure compensation opening 70 d.

The pneumatic connection 48 d has a bore through the cylinder wall 404 d and a ring flange surrounding the bore on the outside of the housing and serves to supply the control valve with pressure medium, in the present case compressed air, which is supplied via a pneumatic line, not shown, from a pneumatic source. The pressure equalization opening 70 d is designed as a simple bore in the cylinder wall 404 d and lies at the same axial height as the pneumatic connection 48 d and is offset in relation to the pneumatic connection 48 d in the circumferential direction by an angle of approximately 23 ° with respect to the valve axis B ″. Furthermore, the control valve 42 d has at its end opposite the hydraulic connection 54 d a pneumatic connection in the form of a coaxial to the valve axis B '' blind bore 430 d in the second housing part 402 d, which is used to connect the control valve to an associated pressure medium power cylinder arrangement, here a pneumatic cylinder arrangement, an actuator comprising the control valve is used.

In order to implement the control states, firstly the pneumatic connection between the pneumatic source and the pneumatic cylinder arrangement via the pneumatic connection 48 d and the pneumatic connection 430 d, secondly the pneumatic connection between the pneumatic cylinder arrangement and the pressure compensation opening 70 d via the pneumatic connection 430 d and thirdly the essentially pneumatic-tight closure of the pneumatic cylinder arrangement, the control valve 42 d has different pressure medium passage openings and pressure medium passages, of which the pressure medium passage 416 d between the second valve element 94 d and the inner section 408 d of the second housing part 402 d has already been mentioned. This pressure medium passage or annular space 416 d is connected to the blind bore of the pneumatic connection 430 d via radial bores 432 d in the second housing part 402 d. Furthermore, the second valve element 94 d has an oblong hole 440 d running obliquely to the valve axis B ″ or obliquely to a projection of the valve axis B ″ on the surface of the cylindrical wall section 414 d of the second valve element 94 d Curvature of the wall section 414 d apart - extends straight in the axial direction and in the circumferential direction and is open radially inward to the annular space 416 d. The elongated hole 440 d is open radially outwards to the inner surface of the wall section 412 d of the first valve element. In other words, the elongated hole 440 d is delimited radially outwards by the inner surface of the wall section 412 d.

The first valve element 92 d has in the wall section 412 d two pressure medium passage openings 442 d and 444 d, which, like the pneumatic connection 48 d and the pressure compensation opening 70 d, are staggered in the circumferential direction, but not in the axial direction. The two pressure medium passage openings 442 d and 444 d in the first valve element 92 d work together with the pressure medium passage opening in the second valve element 94 d in the form of the elongated hole 440 d in order to realize the control states of the valve. Depending on the position of the two valve elements relative to one another, only the pressure medium passage opening 442 d or only the pressure medium passage opening 444 d opens to the elongated hole 440 d or both pressure medium passage openings 442 d and 444 d open radially inward through the elongated hole 440 d surrounding wall section 414 d of the second valve element is closed. This is explained in more detail below.

To the radially outside, the two pressure medium passage openings 442 d and 444 d open into a respective axially parallel groove-shaped recess 446 d and 448 d on the outside of the wall section 412 d of the first valve element 92 d, which is therefore closed radially inwards ( apart from the pressure medium passage opening 442 d or 444 d) and is open radially outwards to the inside of the cylinder wall 404 d. The two recesses 446 d and 448 d are arranged in such a way and have such an axial length that (regardless of the current axial position of the first valve element 92 d) always a pressure medium connection (here pneumatic connection) between the pneumatic connection 48 d and pressure medium passage opening 442 d the recess 446 d and a Druckmittelver connection (here pneumatic connection) between the pressure compensation opening 70 d and the pressure medium passage opening 444 d via the recess 448 d. The pneumatic connection 48 d is therefore always covered radially inward by the recess 446 d and is thus open to the latter, and the pressure compensation opening 70 d is therefore always covered radially inward by the recess 448 d and is thus open to the latter. The presence or absence of a pneumatic connection between the pneumatic connection 48 d and the pneumatic connection 430 d or between the pressure compensation opening 70 d and the pneumatic connection 430 d thus depends solely on the relative position of the two valve elements to one another, more precisely from the resulting overlap or non-overlap between the pressure medium passage opening 442 d and oblong hole 440 d or pressure medium passage 444 d and oblong hole 440 d.

The mobility of the two valve elements 92 d and 94 d relative to one another is limited by engagement means, which protrude radially outward from the second valve element 94 d and are integral with this pin 450 d and obliquely to the valve axis B ″ or to the valve axis B. '' include a parallel surface line (= projection of the valve axis B '' on the surface of the cylindrical wall section 412 d) of the first valve element 92 d elongated hole 452 d in the wall section 412 d of the first valve element 92 d, in which the pin 450 d engages. So that the two valve elements can be inserted into one another while producing the engagement between the pin 450 d and the elongated hole 452 d, the elongated hole 452 d is open toward the end of the first valve element 92 d opposite the end wall 418 d. To distinguish it from the elongated hole 440 d serving as a pressure medium passage opening in the second valve element 94 d, the elongated hole 452 d is referred to below as a slot 452 d in the first valve element 92 d.

The pin 450 d on the second valve element protrudes radially outward through an opening 454 d in the cylinder wall 404 d of the first housing part 400 d via the cylinder wall 404 d and serves to couple the movement of the second valve element 94 d to the release bearing arrangement or the release bearing arrangement side of the Pressure medium power cylinder arrangement (here pneumatic cylinder arrangement). Each axial position of the release bearing arrangement thus corresponds to a rotational position of the second valve element 94 d in the valve housing 90 d, with a clear association between the axial position of the release bearing arrangement and the associated rotational position of the second valve element 94 d. The current position of the release bearing arrangement is thus represented as the actual variable by the position of the second valve element. If the control valve 42 d is integrated in the control valve assembly 40 of FIG. 1, the coupling element 74 protruding from the control valve assembly 40 can be articulated inside the control valve assembly 40 to the pin 450 d in order to couple the movement between the second valve element 94 d and the release bearing arrangement 32 to be provided.

The boundary edge 456 d of the slot 452 d, which is more distant in a longitudinal section through the first valve element 92 d from the end wall 418 d of the first valve element, is important for the correct functioning of the control valve despite the wear of the coupling occurring over time. If the hydraulic slave cylinder 420 d is not acted upon by hydraulic oil from the assigned master cylinder, the first valve element 92 d is displaced by the pressure force of the spring 424 d in the direction of the end wall 406 d of the first housing part 400 d until the limiting edge, which can also be designated as the control edge 456 d of the slot 452 d strikes the pin 450 d. This applies regardless of the axial position of the release bearing arrangement, ie also in the case of a fully engaged clutch. In the course of an increasing and increasing clutch wear, the rotational position of the second valve element 94 d will change in the fully engaged state (basic state) of the assigned friction clutch, namely in the direction of the arrow V shown in FIG. 8. This direction of rotation of the second valve element 94 d or the pin 450 d is opposite to the direction of rotation of the second valve element 94 d or pin 450 d when the clutch is disengaged (arrow A in FIG. 8). Corresponding to the clutch-related rotation of the second valve element 94 d in the engaged state, the interaction of the pin 450 d with the boundary edge 456 d of the slot 452 d of the first valve element 92 d results in a corresponding clutch wear-related shift of the clutch in the fully engaged state without clutch actuation from First valve element 92 d assumed basic state position along the valve axis B ″ in the direction of the end wall 406 d of the first housing part 400 d, that is to say in the sense of a reduction in size of the hydraulic slave cylinder 420 d.

With the help of the spring 424 d, the first valve element 92 d in the basic state of the actuating device without clutch pedal actuation (with the clutch fully engaged) is always, i.e. regardless of the state of wear of the clutch linings, in a defined manner by means of the pin 450 d and the aforementioned limiting edge 456 d Relative position with respect to the second valve element held. The course of the boundary edge 456 d corresponds to the course of the elongated hole 440 d, so that in the basic state there are always identical conditions with respect to the elongated hole 440 d and the pressure medium passage openings 442 d and 444 d, namely a complete coverage between elongated hole 440 d and the pressure medium passage opening 444 d leading to the pressure compensation opening 70 d (cf. in particular FIGS. 9 and 14 which, like FIGS. 8, 10 to 13, show the control valve in the basic state without clutch actuation and fully engaged clutch in the event of moderate clutch wear) . In the basic state mentioned, a pneumatic connection between the pneumatic cylinder arrangement and the pressure compensation opening 70 d is therefore always established.

Is a clutch pedal operation, the hydraulic slave cylinder 420 d supplied with hydraulic oil in the course, as it comes under the action of the inflowing hydraulic oil d to an axial displacement of the first valve member 92 against the force of the spring 424 d. The width of the slot 452 d in the first valve element is dimensioned such that in the event of a stop of the other limiting edge 458 d, which runs parallel to the limiting edge 456 d (thus corresponding to the elongated hole 440 d), on the pin 450 d of the second valve element 94 d an at least partial overlap between the elongated hole 440 d and the pressure medium passage opening 442 d is made, the elongated hole 440 d has not yet been run over by the passage opening 442 d in the axially displaced first valve element 92 d, so that in any case one Pneumatic connection between the pneumatic source, not shown, and the pneumatic cylinder arrangement is established. The above statement applies under the generally unrealistic assumption that the second valve element has not yet twisted out of the rest position in the direction of arrow A ( FIG. 8) due to a supply of compressed air to the pneumatic cylinder arrangement, so that it even stops at Boundary edge 458 d can come at pin 450 d.

The operation of the control valve already indicated above becomes clearer from a consideration of FIGS. 15a to f, which show a sequence of cross sections through the control valve of FIGS. 8 to 14 for different positions of the valve elements in the course of disengaging the clutch. The figures are idealized and unrealistic in that a rotation of the second valve element resulting from a displacement of the first valve element via a change in the position of the release bearing arrangement is not already taken into account in the same partial figure. The figures thus correspond to a situation in which one of the two valve elements was held in place during a transition from one sub-figure to the next or the clutch was actuated only in stages in order to show their movements separately from one another for the sake of clarity.

In FIGS. 15a to 15f, a cross section through the control valve in a pressure medium is the two-passage openings 442 shown d and 444 d intersecting plane, respectively. Depending on the axial position of the first valve element 92 d, this results in a different position of the sectional plane in relation to the valve housing 90 d and the second valve element 94 d. In FIGS. 15e and 15f of the pneumatic connection is represented by dashed lines 48 d, because it does not matter whether the sectional plane passes through the pneumatic port 48 d (corresponding to d and by the pressure outlet port 70) or not.

The possible range of rotation of the second valve element 94 d relative to the first valve element 92 d or the rotatability of the pin 450 d between the boundary edge 456 d and the boundary edge 458 d of the slot 452 d is indicated in the figures by broken lines. In the course of the axial displacement of the first valve element 92 d against the force of the spring 424 d, the limiting edge 458 d approaches the pin 450 d, so that for the axial position of the first valve element 92 d achieved in each case, another angle of rotation range made possible by the slot 452 d for the Rotation of the second valve element 94 d relative to the first valve element 92 d results. Depending on the axial position of the first valve element 92 d, the elongated hole 440 d appears in the respective cross section at a different angular position, so that the second valve element appears rotated, provided that the rotational position of the pin 450 d is not taken into account, which clearly indicates the rotational position of the second valve element 94 d indicates.

Fig. 15a corresponds to the situation of Fig. 14. The clutch is engaged, and the slot 440 d and the pressure medium passage opening 444 d are in overlap, so that a pressure medium connection (here Pneumatic connection) between the pressure compensation opening 70 d and the pneumatic cylinder the arrangement is made. In the course of a clutch pedal actuation, the first valve element 92 d is axially displaced against the force of the spring 424 d. Fig. 15b shows an intermediate position, in which the two pressure medium passage openings 442 d and 444 d in the first valve element 92 d are closed by the wall portion 414 d delimiting the elongated hole 440 d of the second valve element 94 d. The release bearing arrangement and, accordingly, also the second valve element 94 d have not yet moved, since no compressed air has yet been able to be supplied to the pneumatic cylinder arrangement.

In Fig. 15c, the first valve element 92 has an axial position d reached in which the pressure-medium passage orifice 442 d, the elongated hole 440 d partially obscured. The pressure medium passage opening 444 d is closed by the wall section 414 d. Accordingly, there is a pneumatic connection between the pneumatic source, not shown, and the pneumatic cylinder arrangement via the pneumatic connection 48 d, the groove-shaped recess 446 d, the pressure medium passage opening 442 d, the elongated hole 440 d, the annular space 416 d, which cannot be seen in FIG. 15 Radial bores 432 d and the pneumatic connection 430 d, whereas the pressure compensation opening 70 d is separated from the pneumatic cylinder arrangement. In Fig. 15c, the second valve element 94 is shown d untwisted opposite Figures 15a and 15b. the release bearing arrangement has not yet moved.

The resulting rotation of the second valve element 94 d due to the establishment of the pneumatic connection between the pneumatic source and the pneumatic cylinder arrangement and the resulting displacement of the release bearing arrangement, with the first valve element 92 d held, is shown in FIG. 15d. The second valve element has rotated relative to its original position in FIGS . 15a, b, c in the clockwise direction, so that again both pressure medium passage openings 442 d and 444 d are closed ver. Such a situation can generally only occur if the first valve element 92 d is gradually shifted in the axial direction in the course of a clutch actuation, for example in accordance with a gradual depression of the clutch pedal. FIG. 15e then shows the situation when the first valve element 92 is displaced further d in axial direction so that again a pneumatic connection between the pneumatic source and the pneumatic cylinder arrangement via the pressure medium passage opening 442 d and the elongated hole is made 440 d. In general, the and 15e movements shown in FIGS. 15c, 15d will not be separated from each other, at least not when the first valve element is displaced 92 d in the course of a normal, continuously extending clutch pedal operation continuously along the valve axis B ''.

Due to the restoration of the pressure fluid connection, in this case bond Pneumatikver, between the pneumatic source and the pneumatic cylinder arrangement of FIG. 15e moves the release bearing under the influence of the incoming compressed air further out with a corresponding rotation of the second valve element 94 d, wherein Fig. 15f shows an intermediate state or a final state, in which the two pressure medium passage openings 442 d and 444 d are closed again by the wall section 414 d of the second valve element 94 d. It is assumed here that the volume of the master cylinder assigned to the slave cylinder 420 d (here the clutch pedal-operated master cylinder) is dimensioned such that FIG. 15f shows a final state which results when the clutch pedal is fully depressed in the fully disengaged state, when the axial position the release bearing arrangement corresponds to the desired value (= reference variable) predetermined by the axial position of the first valve element 92 d. The difference between the actual variable and the reference variable, which is represented by the relative position of the two valve elements, thus assumes the value zero in the situation according to FIG. 15f.

As can be seen from the original position of the pin 450 d in dashed lines in FIGS. 15d, 15e and 15f relative to the angular range for the pin 450 d permitted by the slot 452 d, the angle of rotation of the second valve element 94 d is corresponding to the fully engaged state FIG. 15a slightly larger than the d nem from the slot 452 at solids contents of the first valve member 92 d approved rotation angle range. The angle of rotation of the second valve element 94 d corresponding to a complete disengagement of the clutch could, however, also be significantly larger than the angle of rotation range permitted by the slot 452 d with the first valve element 92 d held tight, or correspond exactly to this, or - if the elongated hole 440 d and the pressure medium were designed accordingly Passage openings 442 d and 444 d - can also be smaller than the angle of rotation permitted by slot 452 d while first valve element 92 d is held. This can be adjusted by correspondingly matching the volumes or dimensions of the slave cylinder 420 d and the associated master cylinder.

The statements made with regard to FIG. 15 apply to the sequence of cross sections shown in FIG. 16, which shows the sequence of movements of the movement of the valve elements during coupling. FIG. 16a 15f shows a situation in which the first valve member 92 d with respect to the axial end position shown in FIG. Another step in the direction towards the end wall 406 d of the valve housing 90 d by the action of the compression spring has moved 424 d, since the clutch pedal in a less depressed position was transferred or released and accordingly hydraulic oil could flow back from the hydraulic slave cylinder 420 d to the master cylinder assigned to the clutch pedal. In the position of the first valve element 92 d shown in FIG. 16 a, compared to the situation in FIG. 15 f, there is another section of the elongated hole at the level of the pressure medium passage openings 442 d and 444 d, which partially coincides with that with the pressure compensation opening 70 d related pressure medium passage opening 444 d covers, so that now compressed air from the pneumatic cylinder arrangement can flow out of the pressure compensation opening 70 d via the control valve, so that the release bearing arrangement can be moved axially in the coupling direction by the force of the diaphragm spring of the clutch. Fig. 16b shows an intermediate position with the first valve element 92 d held in the position according to Fig. 16a, in which the second valve element 94 d has rotated so far back towards the rest position according to Fig. 15a that the pressure medium passage openings 442 d and 444 d are covered again by the wall section 414 d delimiting the elongated hole 440 d. In the course of a further return movement of the first valve element 92 d in the direction of the end wall 406 d, the situation according to FIG. 16 c then arises, in which the ventilation connection between the pneumatic cylinder arrangement and the pressure compensation opening is again established via the elongated hole 440 d and the pressure medium passage opening 444 d is. In Fig. 16d, the second valve member 94 then has its end or d rest rotational position corresponding to the situation according to Fig. 15a reaches again, while the first valve member 92 d nor with respect to the axial position shown in FIG. 15a is shifted. Via an intermediate position shown in FIG. 16 e, the first valve element 92 d then reaches the end or rest position according to FIG. 15 a predetermined by the delimiting edge 456 d of the slot 452 d, in which the relevant section of the elongated hole 440 d then reaches the pressure medium passage opening 444 d completely covered, so that the permanent vent connection between the pneumatic cylinder arrangement and the pressure compensation opening 70 d is established via the control valve in the basic state of the actuating device.

The preceding description of FIGS. 15 and 16, which - as stated - in some cases unrealistically separate the movements of the first valve element 92 d and the second valve element 94 d, makes it clear that with an axial displacement of the first valve element 92 d, the with its axial position represents the command variable, successively different sections of the elongated hole 440 d arranged at the same height as the pressure medium passage openings 442 d and 444 d in the first valve element 92 d and are therefore decisive with regard to the control function of the control valve (switching between the three control states). Due to the oblique position of the elongated hole 440 d in the second valve element, the relevant sections of the elongated hole 440 d are at different angular positions, with either the elongated hole 440 d at least partially covering the pressure medium passage opening 442 d connected to the pneumatic connection 48 d or the elongated hole 440 d at least partially covers the pressure medium passage opening 444 d connected to the pressure compensation opening 70 d, or both pressure medium passage openings 442 d and 444 d are completely closed by the wall section 414 d delimiting the elongated hole 440 d. Considering only the cross-sections shown in FIG. 15 and 16 without considering the angle posi tion of the pin 450 d, so a large resemblance to the situation occurs in the embodiment of Fig. 5 wherein the elongated hole 440 d with the bore 202 b corresponds and the two Pressure medium passage openings 442 d and 444 d correspond to the openings 410 b and 412 b. The assignment of the valve elements to the reference variable and the actual variable is, however, opposite in the exemplary embodiment in FIG. 5. Similar to the exemplary embodiment in FIG. 5, the sections of the first and second valve elements delimiting the elongated hole 440 d or the pressure medium passage openings 442 d and 444 d can be understood as control edges which release or block pressure medium connections within the control valve if they be moved past an assigned pressure medium passage opening.

Instead of a single elongated hole 440 d in the second valve element 94 d according to the exemplary embodiment of FIGS . 7 to 16, which in cooperation with the pressure medium passage opening 442 d on the one hand or 444 d on the other hand, for establishing a pneumatic connection between the pneumatic cylinder arrangement and the pneumatic source on the one hand or pneumatic cylinder arrangement and Pressure equalization opening 70 d serves on the other hand, two separate, circumferentially offset elongated holes 440 d can be provided, one of which is used to connect to the pneumatic connection of the control valve and the other for establishing the connection to the pressure equalization opening. A control valve with two separate elongated holes in the radially inner, rotatable second valve element 94 e is shown schematically in FIG. 17 for the basic state of an actuating device comprising the valve (basic state with the clutch fully engaged without clutch actuation), the upper part of FIG. 17 being one Longitudinal section in a plane comprising the valve axis through the control valve and the lower part of FIG. 17 shows a cross section orthogonal to the valve axis. In the upper part of FIG. 17, the cross-sectional plane for the lower part of FIG. 17 is dashed and indicated with the direction of view indicated by arrows. Correspondingly, in the lower part of FIG. 17 the section plane and the direction of view for the upper part of FIG. 17 are indicated by arrows.

In the control valve of FIG. 17, the elongated hole 440 e shown schematically in the upper part of FIG. 17 is used to produce a pressure medium connection between the pressure medium cylinder arrangement and an associated pressure medium source via the elongated hole 440 e in the second valve element 94 e and via the associated pressure medium passage opening 442 e in the radially outer, displaceable first valve element 92 e. The pressure medium connection is not shown in detail; it is only schematically shown a large opening 460 e in the valve housing 92 e, which can be thought of as a pressure medium connection, in particular a pneumatic connection, for understanding the functioning of the control valve.

A second elongated hole 441 e is also approximately opposite the elongated hole 440 e with respect to the longitudinal sectional plane in the second valve element and covers a pressure medium passage opening 444 e in the axially displaceable first valve element 92 e. The pressure medium passage opening 444 e opens to an opening 462 e serving as a pressure compensation opening in the valve housing 92 e.

If the first valve element 92 e, which represents the guide size with its axial position, is moved as a result of a clutch actuation, in particular clutch pedal actuation in the direction of the arrow (see upper part of FIG. 17), then there is an overlap between the elongated hole 440 e and the pressure medium passage opening 442 e, while previously the overlap of the elongated hole 441 e and the pressure medium passage opening 444 e was removed, so that now a pressure medium connection between the pressure medium source and the pressure medium cylinder arrangement via pressure medium passage opening 442 e and slot 440 e is made . A resulting disengagement movement of the release bearing arrangement is converted into a corresponding rotary movement of the second valve element 94 e in the direction of the arrow in the lower part of FIG. 17 until the actual size is equal to the desired size (= command variable) and both pressure medium passage openings 442 e and 444 e are covered by the wall sections of the second valve element 94 e delimiting the elongated holes 440 e and 441 e, and the pressure medium cylinder arrangement is accordingly separated both from the pressure medium source and from the pressure medium compensation opening, so that the release bearing arrangement maintains the axial position reached. If the clutch pedal is then released again, corresponding movements (axial displacement of the first valve element 92 e and rotation of the second valve element 94 e) result in the opposite direction until the state according to FIG. 17 is reached again. For this purpose, reference can be made to the explanations relating to FIGS. 15 and 16, which can be easily transferred to the control valve 17 . It is still to be added that the two elongated holes 440 e and 441 e are constantly connected to the pneumatic cylinder arrangement via the tube interior of the control valve delimited by the second valve element 94 e and a pressure medium connection, not shown, so that the control states are achieved solely through the two elongated holes 440 e and 441 e in cooperation with the pressure medium passage opening 442 e and 444 e can be realized.

The control valve of FIG. 18 differs from the control valve of FIG. 17 in that the two elongated holes 440 f and 441 f are provided in the axially movable first valve element 92 f, which represents the reference variable, whereas the pressure medium passage opening interacting with the elongated hole 440 e 442 f and the pressure medium passage opening 444 f cooperating with the elongated hole 441 f are provided in the rotatable second valve element 94 f. This results in a slightly different arrangement of the elongated holes and pressure medium passage openings relative to one another than in the control valve of FIG. 17.

Fig. 19 shows a control valve, wherein the radially inner, rotatable valve member as the first, the reference variable representative of the valve element 92 is g, the radially outer, axially movable valve element whereas a second, the actual quantity representative of valve element 94 serves g. As with the control valve Fig. 18, the radially outer, displaceable valve element, here the second valve element 94 g, the two elongated holes 440 g and 441 g, and the radially inner, rotatable valve element, here the first valve element 92 g, the two pressure medium Through openings 442 g and 444 g. Due to the different assignment of the two valve elements with respect to the representation of the command variable and the actual variable, there is a different relative arrangement of the elongated holes and pressure medium passage openings compared to the example according to FIG. 18.

The control valve of FIG. 20 differs from the control valve of FIG. 19 in that the first valve element 92 h, which lies radially on the inside and is rotatable, has the two elongated holes 440 h and 441 h, whereas the two pressure medium passage openings 442 h and 444 h are provided in the radially outer, axially displaceable valve element, here the second valve element 94 h. This results in a corresponding arrangement of the elongated holes and pressure medium passage openings relative to one another.

In the embodiments of FIGS. 17 to 20 is in each case the radially outer valve element the axially displaceable, against which the radially inner valve element is rotatable. A reverse situation is shown in the embodiments of Fig. 21 to Fig. 24, in which the radially inner valve element is displaceable valve element, against which the radially outer valve element is rotatable.

In the two exemplary embodiments of FIGS . 21 and 22, the displaceable, radially inner valve element serves as the first valve element 92 j or 92 k representing the reference variable, whereas the radially outer, rotatable valve element serves as the second valve element 94 j or represents the actual variable. 94 k serves. In the exemplary embodiment in FIG. 21, the second valve element 94 j has the elongated holes 440 j and 441 j, whereas the pressure medium passage openings 442 j and 444 j are provided in the first valve element 92 j. In contrast to this, in the exemplary embodiment in FIG. 22 the pressure medium passage openings are provided in the second valve element 94 k and the elongated holes in the first valve element 92 k.

The two exemplary embodiments of FIGS . 23 and 24 differ from the exemplary embodiments of FIGS . 21 and 22 in that the radially outer, rotatable valve element serves as the first valve element representing 92 l and 92 m, respectively, while the rudially inner, displaceable valve element serves as the second valve element 94 l or 94 m representing the actual size. In the embodiment of FIG. 23, the elongated holes 440 l and 441 l are provided in the second valve element 94 l and the associated pressure medium passage openings 442 l and 444 l in the first valve element 92 l. In contrast, in the exemplary embodiment according to FIG. 24, the first valve element 92 m has the elongated holes 440 m and 441 m, whereas the second valve element 94 m has the pressure medium passage openings 442 m and 444 m.

In all embodiments of Figs. 17 to 24, the relative arrangement of the slots and associated pressure-medium passage openings in the shown in the figures the ground state is sized to guide with the clutch without a clutch pedal operation on the assignment of the valve elements and actual size, the type of mobility of the respective Valve element (rotatable or displaceable) and in terms of which valve element has the elongated holes and which the valve element has the pressure medium passage openings, so that the control valve fulfills its functions properly. It should also be noted that the two long holes need not be provided in the same valve element. Thus, the first valve element can have the elongated hole 440 and the pressure medium passage opening 444 and the second valve element can have the elongated hole 441 and the pressure medium passage opening 442 , and vice versa.

In Figs. 25 to 27 three specific embodiments are shown for substantially the control valve of FIG. 23 corresponding control valve. The control valve of Fig. 25 has a housing 90 n with an internal pipe section 470 n, via a connecting line 472 n to the associated pressure-medium cylinder arrangement is in communication and inwardly n to an interior 474 of the control valve is open. The tube section 470 n is surrounded radially on the outside by a circular cylindrical wall section 414 n of the axially displaceable second valve element 94 n coaxial with the valve axis B ″ and which has the two elongated holes. In Fig. 25 the axial extent of the elongated hole 440 is indicated by dashed lines n, which fully with his in the section plane the valve axis B '' lying portion with the assigned pressure medium passage opening 442 n in the radially outer, circular cylindrical wall portion 412 n of the Venti Salmon B '' rotatable first valve element 92 n just covered, so that between a pressure medium source, not shown, and the pressure medium cylinder arrangement via a pressure medium line 476 n, the pressure medium passage opening 442 n, the elongated hole 440 n, the interior 474 n, the pipe section 470 n and the pressure medium line 472 n a pressure medium connection is made. The resulting movement of the release bearing arrangement is transmitted by means of a hydraulic master cylinder assigned to the release bearing arrangement, which serves as a measuring cylinder, via a hydraulic line 478 n to the second valve element 94 n. For this purpose, a hydraulic slave cylinder 420 n is formed in the control valve 42 n in the form of an annular cylinder enclosing the tubular section 470 n, to which the second valve element 94 n is assigned as an annular piston. A disengagement movement of the release bearing arrangement is accordingly implemented hydraulically in an axial movement of the second valve element 94 n against the force of a biasing spring 424 n. The control valve can be conveniently used directly on the clutch pedal, since here the rotational movement of the clutch pedal to its rotary bearing directly on the first valve element 92 n by means of which protruding from the control valve housing pin section can be transmitted without the need for expensive links. The hydraulic coupling of the second valve element to the release bearing arrangement has the advantage that a hydraulic translation is possible, so that the control path (control path) need not be the same as the release path.

The control valve of FIG. 26 largely corresponds to the control valve of FIG. 25. However, the hydraulic slave cylinder 420 p is provided at the other axial end of the second valve element 94 p. For specifying the guide size, i.e. the rotational position of the first, radially outer valve element 92 p, projecting coupling rods 480 p are used through arcuate passages on the slave cylinder 470 p opposite valve end, which carry a coupling ring 482 p at their end projecting from the control valve. The coupling ring 482 p could, for example, be designed as a gearwheel with a ring gear on its outer circumference, by means of which the rotary movement of the clutch pedal when depressed could be converted into a corresponding rotary movement of the first valve element 92 p.

In contrast to the control valve of FIG. 26, no hydraulic slave cylinder is provided in the control valve of FIG. 27, but an end section of the second valve element 94 q protrudes from the valve housing, to which the release bearing arrangement can be mechanically coupled, for example, around the second valve element 94 q to move according to the movement of the release bearing arrangement along the valve axis B ''. For example, the valve can be attached directly to the pressure medium cylinder arrangement in order to use the "disengagement signal" directly. For the mechanical coupling of the radially outer, rotatable, first valve element 92 q with a clutch pedal arrangement or the like, a pin 450 q protrudes radially from the valve housing 90 p.

The control valve of FIG. 28 corresponds to the control valve of FIG. 17 in that the radially outer valve element which can be displaced along the valve axis B '' serves as the first valve element 92 r, which represents the reference variable, and the radially inner, rotatable valve element serves as the second Valve element 94 r is used, which represents the actual size, wherein the first valve element 92 r has the pressure medium passage openings and the second valve element 94 r has the elongated holes. The first valve element 92 r forms, together with an annular space in the control valve surrounding the second valve element 94 r, a hydraulic slave cylinder 420 r, which is connected via a hydraulic line 484 r to a hydraulic pedal cylinder which can be actuated by a clutch pedal, in order to longitudinally extend the first valve element 92 r in accordance with the clutch pedal actuation the valve axis B ''. The second valve element 34 r is integrally formed with a pivoting arm 486 r extending radially to the valve axis B ″, which with a corresponding arrangement of the control valve 42 r similar to the control valve 42 b of FIG. 2 on the release bearing arrangement for converting the movement of the release bearing arrangement along the coupling axis can serve in a corresponding rotational movement of the second valve element 94 r. For this purpose, the swivel arm 486 r can be spring-biased against the release bearing arrangement or the release bearing arrangement side of the pressure medium power cylinder arrangement.

In the exemplary embodiment in FIG. 29, the relative radial arrangement of the first valve element 92 s and the second valve element 94 s is reversed compared to the exemplary embodiment in FIG. 28; the rotatable second valve element 94 s, which has the elongated holes, is therefore located radially further outward than the displaceable first valve element 92 s, which has the associated pressure medium passage openings. For the supply of pressure medium, in particular the supply of compressed air, the opening in the valve housing 90 s in the above exemplary embodiments 25 to 28 is an opening 460 s as a pneumatic connection 48 s for the pressure line 476 s in the valve housing 90 s with the ring segment-like pressure medium space 460 s between the valve housing wall and the second valve element 94 s in the area of the elongated hole 440 s. To transmit the axial movement of the release bearing arrangement to the second valve element 94 s, the latter carries, similarly to the first valve element 92 p of the exemplary embodiment in FIG. 26, coupling rods 480 s which protrude from the valve housing at the opposite end of the slave cylinder 420 s and with a coupling ring 482 s are connected, which is formed in one piece with a radially projecting coupling or swivel arm 486 s. By means of the optionally spring-biased coupling arm 486 s, the axial movement of the release bearing arrangement or release bearing arrangement side of the pressure medium cylinder arrangement can be converted into a corresponding rotary movement of the second valve element 94 s via the coupling ring 482 s and the coupling rods 480 s. It should also be pointed out that the control valve of FIG. 29 essentially corresponds to the control valve of FIG. 21.

The control valve of FIG. 30 substantially corresponds to the control valve of Fig. 19 and thus has a radially outer, displaceable second valve element 94 t with slots and a radially inner, rotatable, first valve element 92 t with the elongated holes assigned pressure medium passage openings . Similar to the embodiment of FIG. 25, the second valve element 94 t forms, together with an annular space in the valve housing 90 t, a hydraulic slave cylinder which is connected via a hydraulic line 478 t to an associated master cylinder which detects the axial position of the release bearing arrangement in order to control the movement of the Release bearing arrangement or the release bearing arrangement side of the pressure medium cylinder arrangement into a corresponding axial movement of the second valve element 94 t. The coupling of the first valve element 92 t takes place, as in the embodiment of FIG. 25, via the pin section of the first valve element 92 t protruding along the valve axis B '' from the valve housing 90 t, on which, for example, a clutch pedal directly coaxial with the valve axis B '' Can attack the pivot axis.

A further exemplary embodiment of a control valve according to the invention is shown in FIGS. 31 and 32, in which, in deviation from the above-mentioned sequence of the small letters characterizing the embodiments, the small letter c is used for identification. With regard to the exemplary embodiment of FIGS. 31 and 32, express reference is made to the preceding description of the other exemplary embodiments, in particular the exemplary embodiment of FIGS. 2 to 6, and only the differences between the exemplary embodiments are described.

The control valve 42 c, like the control valve 42 b, has two valve elements arranged in a valve housing 90 c, a first valve element 92 c and a second valve element 94 c. In contrast to the embodiment example of FIGS . 2 to 6, both valve elements can be displaced along a valve axis B '' and represent the reference variable, the actual variable and the differential variable by displacement or axial positions.

A great similarity between the control valve of FIGS. 2 to 6 and the control valve of FIGS. 31 and 32 results from the fact that the control valve of FIGS. 31 and 32, in relation to its design in the axial direction, to a certain extent a "development" of the control valve of FIG based. 2 to 6 on its formation in the circumferential or rotational direction corresponds substantially. A corresponding rotational position of the valve elements 92 b and 94 b can thus be assigned to each axial position of the valve elements 92 c and 94 c.

The valve body 90 c has a circular cylindrical recess 180 c coaxial with the valve axis B ″, in which the second valve element 94 c is slidably received along the valve axis B ″. The second valve element 94 c also has a coaxial, cylindrical cylindrical recess 300 c from the valve axis B ″, in which the first valve element 92 c is arranged with a control section 302 c along the valve axis B ″ displaceably. The first valve element 92 c has a section 200 c projecting out of the valve housing 90 c and receiving the reference variable, and the second valve element 94 c has a section 208 c projecting out of the valve housing 90 c on the opposite side and receiving the actual size.

The valve housing 90 c has three bores 182 c, 186 c and 184 c which are offset with respect to one another in the axial direction (valve axis B ″) and follow one another in this order in the direction from section 200 c to section 208 c. The axial distance between the holes 182 c and 186 c is equal to the axial distance between the holes 186 c and 184 c. The bores are directed radially with respect to the valve axis B ″ and open into the recess 180 c of the valve housing 90 c. The holes 182 c, 184 c, 186 c are also offset from one another in the circumferential direction; however, this is no longer important for the function of the control valve and only serves to make the control valve short in the axial direction.

The second valve element 94 c 'has three openings 210 c, 214 c and 212 c which are offset with respect to one another in the axial direction (valve axis B''), the openings in the direction from section 200 c to section 208 c following one another in the order mentioned . Each of the openings mentioned is formed by an elongated, axially extending recess and a radially further inner bore provided in the axial center of the recess, so that a connection between the outer space of the second valve element 94 through the elongated recess and the bore c and the recess 300 c provided therein can be produced. In each axial position of the second valve element 94 c is the opening 210 c to the hole 182 c, the opening 214 c to the hole 186 c and the opening 212 c to the hole 184 c is open, since the respective elongated recess of the opening in question is the hole in question covered radially inwards in the valve housing. Without taking the first valve element 92 c into account, there is always a connection between the holes 182 c, 186 c and 184 c and the recess 300 c in the interior of the second valve element 94 c and thus a connection between the bores.

The control section 302 c of the first valve element 92 c now serves to open and close the connections between the bores 182 c, 186 c and 184 c with one another depending on the axial relative positions of the two valve elements. For this purpose, the control section 302 c has two closure sections 306 c and 308 c each forming a control edge, which, if they cover the radially inner bore of the respective opening 210 c or 212 c, close the latter to the recess 300 c in the second valve element 94 c.

Between the two closure sections 306 c and 308 c, the control section 302 c of the first valve element 92 c has an annular recess which is open to the radially outward and forms an annular channel 202 c. The ring channel 202 c is open in each axial relative position of the two valve elements to one another at least to the opening 214 c and thus to the bore 186 c leading to the pressure medium power cylinder arrangement.

Depending on the axial relative position of the two valve elements to one another, the annular channel 202 c is either only open to the opening 214 c and thus to the hole 186 c or either additionally to the opening 212 c and thus to the hole 184 c leading to the pressure medium supply or to the opening 210 c and thus to the opening 182 c, which serves as a pressure compensation opening 70 c, open.

In the basic position of the control valve shown in FIG. 32a, in which the clutch is not disengaged, there is a venting connection between the bore 186c and the bore 182c via the annular channel 202c . If the first valve element 94 c is shifted to the left in accordance with a reference variable which increases, for example as a result of a clutch pedal actuation, as shown in FIG. 32, the radially inner bore of the opening 210 c is first opened up by the closure section 202 c before the Closure section 308 c, which in the basic position has closed the radially inner bore of the opening 212 c, has moved past this radially inner bore until a pressure medium connection between the bores 186 c and 184 c in the control valve housing 90 c via the openings 212 c, 214 c and the ring channel 202 c is produced and the power cylinder arrangement is supplied with pressure medium. Fig. 32b shows the control valve in a state of maximum clutch actuation, in which such a pressure medium connection between the bores gene 184 c and 186 c is made.

In the event that the clutch is not actuated to the maximum, the two valve elements, when the actual size is the same as the command size, assume such an axial relative position to one another that the closure section 306 c closes the radially inner bore of the opening 210 c and the closure section 208 c the radially closes inner bore of the opening 212 c, so that there is no pressure medium connection between the pressure medium power cylinder arrangement on the one hand and neither the pressure compensation opening 70 c nor the bore 184 c leading to the pressure medium supply on the other.

Except for the bores and openings in the valve housing 90 c and in the second valve element 94 c mentioned, the valve housing and the two valve elements 92 c and 94 c are essentially rotationally symmetrical to the valve axis B ″. However, the rotational symmetry-breaking, not shown in the figures rotational position fixing means are provided, which exclude a relative rotation between the second valve element 94 c and the valve housing 90 c, so that it is always ensured that the opening 210 c to the bore 182 c, breakthrough 214 c to hole 186 c and breakthrough 212 c to hole 184 c is open. The holes 182 c, 186 c and 184 c and, accordingly, the openings 210 c, 214 c and 212 c are, as already mentioned, in addition to their mutual offset in the axial direction also in the circumferential direction (based on the valve axis B '') offset from each other to keep the control valve short in the axial direction. In principle, the bores 182 c to 186 c and, correspondingly, the openings 210 c to 214 c could also be pulled apart axially "in such a way that the elongated recesses of the openings extending in the axial direction no longer overlap when projected onto the valve axis B", so that instead of the elongated recesses ring channels in the manner of the ring channel 202 c could be provided on the outer circumference of the second valve element 94 c, in which case the second valve element 94 c could assume any rotational position relative to the valve housing 90 c, as also for the first Valve element (also in the embodiment of FIGS . 31 and 32) is the case.

In summary, the invention relates to an actuating device for a in the drive train of a motor vehicle between an internal combustion engine and a transmission clutch arranged in a bell housing,  comprising a release bearing arrangement and a pressure medium power cylinder the positioning servo arrangement for the release bearing arrangement, the positioning servo arrangement one with a pressure medium Source connected control valve. The control valve includes one Valve arrangement that depends on the axial position of the release bearing arrangement representing the actual size and a target position of the Release bearing arrangement representative reference variable between little at least two control states can be switched. In a first tax state there is a pressure medium connection between the pressure medium power cylinder arrangement and the pressure medium source and in a second control state there is a pressure medium connection between the pressure medium power cylinder arrangement and a pressure equalization opening. The valve assembly includes two movable relative to each other and relative to a valve housing Valve elements, the command variable by the position of a first of the two valve elements and the actual size by the position of a second one two valve elements is represented relative to the valve housing and one of the Actual size and the reference size assigned by the Position of the two valve elements is represented relative to each other.

Claims (69)

1. Actuating device ( 10 ) for a in the drive train of a motor vehicle, in particular commercial vehicle, between an internal combustion engine and a transmission in a bell housing ( 12 ) arranged friction clutch, comprising

• - A release bearing arrangement ( 32 ) for actuating the friction clutch which is movable essentially coaxially with the friction clutch;
• - A positioning servo arrangement with a pressure medium power cylinder arrangement ( 14 ) acting on the release bearing arrangement ( 32 ), which, via a control valve ( 42 ) connected to a pressure medium source ( 51 ), depends on a reference variable representing a desired position and on the axial position of the release bearing arrangement ( 32 ) representing the actual size can be actuated;
  wherein the pressure medium power cylinder arrangement ( 14 ), which in particular comprises a pressure medium ring cylinder ( 16 ) which is essentially concentric with the clutch axis, is arranged within the bell housing ( 12 ) and preferably for exerting a force which is essentially coaxial with the clutch axis (A) on the release bearing arrangement ( 32 ) is formed
  wherein the control valve ( 42 ) comprises a valve arrangement adjustable between a first control state connecting the pressure medium power cylinder arrangement ( 14 ) to the pressure medium source ( 51 ) and a second control state connecting the pressure medium power cylinder arrangement ( 14 ) with a pressure compensation opening ( 70 ), which can be switched between the two control states as a function of a difference variable assigned to the actual variable and the reference variable, the valve arrangement comprising two valve elements ( 92 , 94 ) movable relative to one another and relative to a valve housing and the reference variable by the position of a first ( 92 ) of the two valve elements and the actual size is represented by the position of a second ( 94 ) of the two valve elements relative to the valve housing ( 40 ; 90 ) and the difference size is represented by the position of the two valve elements ( 92 , 94 ) relative to one another.

2. Actuating device ( 10 ) for a in the drive train of a motor vehicle, in particular utility vehicle, between an internal combustion engine and a transmission in a bell housing ( 12 ) arranged friction clutch, comprising

• - A release bearing arrangement ( 32 ) for actuating the friction clutch which is movable essentially coaxially with the friction clutch;
• - A positioning servo arrangement with a pressure medium power cylinder arrangement ( 14 ) acting on the release bearing arrangement ( 32 ), which, via a control valve ( 42 ) connected to a pressure medium source ( 51 ), depends on a reference variable representing a desired position and on the axial position of the release bearing arrangement ( 32 ) representing the actual size can be actuated;
  wherein the control valve ( 42 ) comprises a valve arrangement adjustable between a first control state connecting the pressure medium power cylinder arrangement ( 14 ) to the pressure medium source ( 51 ) and a second control state connecting the pressure medium power cylinder arrangement ( 14 ) with a pressure compensation opening ( 70 ), which can be switched between the two control states as a function of a difference variable assigned to the actual variable and the reference variable, the valve arrangement comprising two valve elements ( 92 , 94 ) movable relative to one another and relative to a valve housing and the reference variable by the position of a first ( 92 ) of the two valve elements and the actual size is represented by the position of a second ( 94 ) of the two valve elements relative to the valve housing ( 40 ; 90 ) and the difference size is represented by the position of the two valve elements ( 92 , 94 ) relative to one another.

3. Actuating device according to claim 1 or 2, characterized records that the valve arrangement depending on the difference Size is adjustable in a third control state, in which the pressure Medium-power cylinder arrangement essentially pressure-tight is completed. 4. Actuating device according to one of the preceding claims, characterized in that the control valve ( 42 ) has a first signal connection ( 54 ) for receiving a command signal indicating the command variable, in particular from a clutch pedal arrangement ( 60 ) and a second signal connection ( 76 ) for receiving an actual value -Size-indicating actual value signal from a transmitter element arrangement ( 72 ) assigned to the release bearing arrangement ( 32 ). 5. Actuating device according to claim 4, characterized in that the command signal and the actual value signal each independently of the other signal on exactly one valve element of the two valve elements, the command signal on the first valve element ( 92 ) and the actual value signal on the second valve element ( 94 ), act directly. 6. Actuating device according to claim 4 or 5, characterized in that the actual value signal is a hydraulic, pneumatic, mechanical, or electrical signal represented in particular by a pressure, a volume, a force, a path, an angle, a current or a voltage , wherein the second signal connection ( 76 ) is optionally assigned converter means ( 420 n; 420 p; 420 t) for converting the actual value signal into the actual variable. 7. Actuating device according to claim 6, characterized in that the converter means ( 420 n; 420 p; 420 t) for converting a pneumatic or hydraulic actual value signal comprise a particularly spring-loaded piston ( 94 n; 94 p; 94 t), which preferably with the second valve element ( 94 n; 94 p; 94 t) coupled or can be coupled, in particular is integral therewith. 8. Actuating device according to one of the preceding claims, characterized in that the positioning servo arrangement a mechanical position control arrangement ( 42 , 64 , 16 , 72 , 74 ) with a position of the release bearing arrangement ( 32 ) directly or indirectly detecting, mechanically coupled or connectable encoder element ( 72 ; 226 b; 450 d; 486 r; 486 s). 9. Actuating device according to claim 8, characterized in that the transmitter element ( 72 ; 226 b; 450 d; 486 r; 486 s) acts on the second valve element ( 94 b; 94 d; 94 r; 94 s), in particular with this is motion-linked or motion-linkable. 10. Actuating device according to claim 9, characterized in that the second valve element ( 94 q) via an optionally with this integral coupling element ( 94 q) with the release bearing arrangement or the release bearing arrangement side of the pressure medium power cylinder arrangement is preferably substantially rigidly coupled or couplable. 11. Actuating device according to claim 9, characterized in that the second valve element ( 94 b; 94 r; 486 s) via a preferably rigidly coupled with this, optionally integral with this, against the release bearing arrangement or the release bearing arrangement side ( 162 b) the pressure medium power cylinder arrangement ( 14 b) pre-tensioned or pre-tensionable coupling element ( 226 b; 486 r; 486 s) is coupled or can be coupled thereto. 12. Actuating device according to one of the preceding claims and according to claim 4, characterized in that the guide signal is a hydraulic, pneumatic, in particular represented by a pressure, a volume, a force, a path, an angle, a current, a voltage or a light intensity , electrical or optical signal, the first signal connection ( 54 ), if appropriate, being assigned converter means ( 234 b; 420 d; 420 r; 420 s) for converting the command signal into the command variable. 13. Actuating device according to claim 12, characterized in that the converter means for converting a pneumatic or hydraulic guide signal comprise a spring-loaded piston in particular ( 236 b; 92 d; 92 r; 92 s), which is preferably connected to the first valve element ( 92 b; 92 d; 92 r; 92 s) coupled or couplable, in particular integral with it. 14. Actuating device according to one of the preceding claims, characterized in that of the elements - first valve element ( 92 ) and second valve element ( 94 ) - one ( 94 b; 92 c; 94 d) at least one section forming a control edge ( 224 b; 306 c, 308 c) having at least three pressure medium openings ( 70 b, 184 b, 202 b; 210 c, 212 c, 214 c; 442 d, 444 d, 430 d) in the other valve element ( 92 b; 94 c ; 92 d) and in the valve housing ( 90 b; 90 c; 90 d), in particular a pressure medium opening ( 202 b) in the other valve element ( 92 b) and two pressure medium openings ( 70 b, 184 b) in the valve housing, works together in at least one relative position of the two valve elements ( 92 b, 94 b; 92 c, 94 c; 92 d, 94 d) to one another when the one valve element moves relative to the other valve element in one direction by moving at least one control edge ( 224 b; 306 c, 308 c) at at least one of the pressure medium openings, in particular de r pressure medium opening ( 202 b) in the other valve element ( 92 b) to interrupt or establish a first pressure medium connection within the control valve, in particular the pressure medium connection between the pressure medium source ( 51 b) and the pressure medium power cylinder arrangement ( 14 b), and another pressure medium connection within of the control valve ( 42 b; 42 c; 42 d), in particular to establish or interrupt the pressure medium connection between the pressure compensation opening ( 70 b; 70 c; 70 d) and the pressure medium power cylinder arrangement ( 14 b). 15. Actuating device according to claim 14, characterized in that the second valve element ( 94 b; 94 d) has at least one portion ( 224 b) forming a control edge. 16. Actuating device according to claim 14 or 15, characterized in that the first valve element ( 92 d) has at least one portion forming a control edge. 17. Actuating device according to one of the preceding claims, characterized in that one of the valve elements - first valve element ( 92 b; 92 d) and second valve element ( 94 b; 94 d) - has at least one in particular pin-like engagement section ( 220 b; 450 d) , which engages in an associated slot-like recess ( 222 b; 452 d) of the other valve element ( 94 b; 92 d), the recess ( 222 b; 452 d) being formed by a recess edge forming at least one stop, possibly with two of the recess limit of both ends is limited to limit the range of motion of the two valve elements ( 92 b, 94 b; 92 d, 94 d) relative to each other. 18. Actuating device according to claim 17, characterized in that the first valve element ( 92 b) has the at least one engagement section ( 220 b). 19. Actuating device according to claim 17, characterized in that the second valve element ( 94 d) has the at least one engagement section ( 450 d). 20. Actuating device according to one of the preceding claims, characterized in that the second valve element ( 94 b; 94 d) is coupled to the first valve element ( 92 b; 92 d) in such a way that the second valve element ( 94 b; 94 d) in a basic state of the actuation device without clutch actuation holds the first valve element ( 92 b; 92 d) in a starting position that preferably takes into account any clutch wear relative to the second valve element ( 94 b; 94 d) in order to provide a defined response of the actuation device at the beginning of a clutch actuation or / and to keep a free travel, in particular clutch wear-induced, at least small, preferably to be avoided. 21. Actuating device according to claim 20, characterized in that the two valve elements ( 92 b, 94 b; 92 d, 94 d) for holding the first valve element ( 92 b; 92 d) have cooperating stops in the starting position, in particular in the form of the at least one engagement section ( 220 b; 450 d) and the recess edge delimiting the recess ( 222 b; 452 d). 22. Actuating device according to one of the preceding claims, characterized in that the control valve ( 42 ) was in a basic condition of the actuating device without clutch actuation which assumes the control state connecting the pressure compensation opening ( 70 ) with the pressure medium power cylinder arrangement ( 14 ). 23. Actuating device according to one of the preceding claims, characterized in that the first ( 92 b; 92 d) and the second ( 94 b; 94 d) valve element in a recess ( 180 b; 180 d) of the Ventilgehäu ses ( 90 b; 90 d) are mounted, one of the valve elements being rotatable about a valve axis (B ';B'') and the other valve element being rotatable either about the valve axis (B'; B '') or along the valve axis (B ';B'') ) is displaceable, the actual variable and the reference variable either both by a rotational position of the respective valve element ( 92 b; 94 b) or one of these variables by a rotational position and the other of these variables by an axial position of the respective valve element ( 92 d; 94 d) are represented. 24. Actuating device according to claim 23, characterized in that of the elements - first valve element ( 92 b; 92 d) and second valve element ( 94 b; 94 d) - a valve element at least two separate pressure medium passage openings ( 210 b, 212 b ; 442 d; 444 d), of which a passage opening in at least one position of this valve element ( 94 b; 92 d) relative to the valve housing ( 90 b; 90 d) with a first pressure medium passage opening ( 70 b; 70 d) of the Valve housing ( 90 b; 90 d) is in pressure medium passage connection and the other passage opening in at least one position of this valve element ( 94 b; 92 d) relative to the valve housing ( 90 b; 90 d) with a second pressure medium passage opening ( 148 b; 48 d ) of the valve housing ( 90 b; 92 d) is in pressure medium passage connection, and that in the other valve element ( 92 b; 94 d) at least one further pressure medium passage opening ( 202 b; 440 d) is provided, one ( 202 b; 440 d) of the at least one further pressure medium passage opening ( 202 b; 440 a) in at least one position of the other valve element ( 92 b; 94 d) relative to the valve housing ( 90 b; 90 d) with a third pressure medium passage opening ( 186 b; 430 d) of the valve housing ( 90 b; 90 d) is in fluid connection. 25. Actuating device according to claim 24, characterized in
that in a first relative position or in a first relative position area of the two valve elements ( 92 b, 94 b; 92 d, 94 d) to one another the further pressure medium passage opening ( 202 b; 440 d) in the other valve element ( 92 b; 94 d ) with a ( 220 b; 442 d) of the at least two separate pressure medium passage openings in one valve element ( 94 b; 92 d) in pressure medium passage connection, and
that in a second relative position or in a second relative position range of the two valve elements ( 92 b, 94 b; 92 d, 94 d) to one another the further pressure medium passage opening ( 202 b; 440 d) in the other valve element ( 92 b; 94 d ) with another ( 212 b; 444 d) of the at least two separate pressure medium passage openings in one valve element ( 94 b; 92 d) is in pressure medium passage connection. 26. Actuating device according to claim 24 or 25, characterized in that
that in at least one position range of the two valve elements ( 92 b, 94 b; 92 d, 94 d) relative to each other and relative to the valve housing ( 90 b; 90 d) via associated pressure medium passage openings ( 184 b, 186 b, 212 b , 202 b, 214 b; 48 d, 430 d, 442 d, 440 d) in the valve housing and in the two valve elements a pressure medium connection between the pressure medium source ( 51 b) and the pressure medium power cylinder arrangement ( 14 b) is made, and
that in at least one other position range of the two valve elements ( 92 b, 94 b; 92 d, 94 d) relative to each other and relative to the valve housing ( 90 b; 90 d) via assigned pressure medium passage openings ( 210 b, 202 b, 214 b, 186 b; 430 d, 444 d, 440 d) in the Ventilge housing and in the two valve elements, a pressure medium connection between the pressure medium power cylinder arrangement ( 14 b) and the pressure compensation opening ( 70 b; 70 d) is made. 27. Actuating device according to one of claims 24 to 26, characterized in that in a third relative position or in a third relative position range of the two valve elements ( 92 b, 94 b; 92 d, 94 d) to each other the one further pressure medium passage opening ( 202 b ; 440 d) is in the other valve element with none of the at least two separate pressure medium passage openings in one valve element in pressure medium passage connection. 28. Actuating device according to one of claims 24 to 27, characterized in that in at least one position of the two valve elements ( 92 b, 94 b; 92 d, 94 d) relative to each other and relative to the valve housing ( 90 b; 90 d) neither a pressure medium connection between the pressure medium power cylinder assembly (14 b) and the pressure medium source (51 b) nor a pressure medium connection between the pressurized fluid power cylinder assembly (14 b) and the pressure compensation opening (70 b; 70 d) is prepared. 29. Actuating device according to one of claims 23 to 28, characterized in that of the elements - first valve element ( 92 b; 92 d) and second valve element ( 94 b; 94 d) - a valve element ( 94 b; 92 d) one for Valve axis (B ';B'') has coaxial ring section ( 204 b; 412 d) which encloses the other valve element ( 92 b; 94 d) of the two valve elements at least in regions radially on the outside. 30. Actuating device according to claim 31, characterized in that the other valve element ( 94 d) of the two valve elements has a coaxial to the valve axis (B '') ring portion ( 414 d), which preferably has at least one pressure medium passage opening ( 430 d, 432 d) having inner section ( 408 d) of the valve housing ( 90 d) at least in regions radially on the outside. 31. Actuating device according to claim 29 or 30, characterized in that a valve element ( 94 b; 92 d) enclosing radially outside, the recess of the valve housing at least partially delimiting valve housing wall ( 90 b; 400 d) and / or to the valve axis (B '') coaxial ring section ( 204 b; 412 d) of the one ( 94 b; 92 d) valve element and / or the ring section coaxial to the valve axis (B '') ( 414 d) of the other valve element ( 92 b; 94 d) have at least one respective pressure medium passage opening ( 70 b, 184 b, 186 b, 210 b, 212 b, 214 b; 48 d, 70 d, 442 d, 444 d, 440 d). 32. Actuating device according to one of claims 1 to 31, characterized in that the first ( 92 b) and the second ( 94 b) valve element in a recess ( 180 b) of the valve housing ( 90 b) about a valve axis (B ') are rotatably supported, the actual size and the reference size being represented by the rotational positions of the respective valve element ( 92 b; 94 b). 33. Actuating device according to claim 32 and claim 29, characterized in that the second valve element ( 94 b) has the coaxial to the valve axis (B ') ring portion ( 204 b) which at least partially encloses the first valve element ( 92 b) radially on the outside . 34. Actuating device according to claim 32 or 33, characterized in that
that the radially outside of a recess ( 180 b) delimiting the inner circumferential surface of the valve housing ( 90 b) surrounds the ring section ( 204 b) of the one valve element ( 94 b) at least two circumferentially extending, circumferentially offset against each other, by a respective section ( 224 b; 240 b; 242 b) of the ring section ( 204 b) has openings ( 210 b, 212 b, 214 b) which are separate from one another and are open to the radially inside and radially outside, as pressure medium through-openings,
that in the valve housing ( 90 b) at least two, in particular radially directed bores ( 182 b, 184 b, 186 b) opening into the recess ( 180 b) are provided as pressure medium passage openings, the orifices of the bores being offset in the circumferential direction and in at least one rotational position of one valve element ( 94 b) each at least partially cover another of the openings and
that in the other valve element ( 92 b) at least one connecting channel as a pressure medium passage opening, in particular a through hole ( 202 b) is provided, which is open to two of the openings in at least one relative rotary position of the two valve elements ( 92 b, 94 b) , in particular in that the two mouth openings of the through hole ( 202 b) are each at least partially covered by another of the openings. 35. Actuating device according to claim 34, characterized in that exactly three bores ( 182 b, 184 b, 186 b), exactly three openings ( 210 b, 212 b, 214 b) and exactly one connecting channel, in particular a radially extending Through bore ( 202 b) are provided, with at least one rotational position of the two valve elements ( 92 b, 94 b) relative to one another and relative to the valve housing ( 90 b) via two ( 184 b, 186 b) of the bores, two ( 212 b, 214 b) the breakthroughs and the connecting channel ( 202 b) a pressure medium connection between the pressure medium source ( 51 b) and the pressure medium power cylinder arrangement ( 14 b) is made and in we least at least another rotational position range of the two valve elements ( 92 b, 94 b) relative to each other and relative to the valve housing ( 90 b) via two ( 182 b, 186 b) the bores, two ( 210 b, 214 b) the openings and the connecting channel ( 202 b) a pressure medium connection between the Pressure medium power cylinder assembly ( 14 b) and the pressure compensation opening ( 70 b) is made. 36. Actuating device according to claim 34 or 35, characterized in that the openings ( 210 b, 212 b, 214 b) separating sections ( 224 b, 240 b, 242 b) of the ring section ( 204 b) are dimensioned such that that in at least one relative rotational position of the two valve elements ( 92 b, 94 b) to one another and / or in at least one rotational position of the one valve element ( 94 b) relative to the valve housing ( 90 b), at least one channel opening of the connecting channel, in particular the opening of the through hole ( 202 b) in the other valve element ( 92 b) and / or at least one of the opening openings of the holes in the valve housing ( 90 b) is closed by a respective section ( 224 b) of the ring section ( 204 b) which in particular forms a control edge. 37. Actuator according to claim 35 or 36, characterized in that the preferably in the axial direction substantially not offset mouth openings of the three bores ( 182 b, 184 b, 186 b) are arranged with the same circumferential angle at a distance from each other and preferably one each cover the same large circumferential angle range. 38. Actuating device according to one of claims 35 to 37, characterized in that the three openings ( 210 b, 212 b, 214 b), which are preferably not axially offset against one another, preferably cover the same circumferential angle range and have the same circumferential angle at a distance from one another are arranged. 39. Actuating device according to claim 37 and 38, characterized in that of the three bores one of the pressure compensation opening ( 70 b) associated bore ( 182 b), one of the pressure medium source ( 51 b) associated bore ( 184 b) and one of the pressure medium Power cylinder arrangement ( 14 b) associated bore ( 186 b) follow one another in a predetermined direction of rotation,
wherein in the basic state of the actuating device ( 10 b) a mouth opening of the through bore ( 202 b) in the first valve element ( 92 b) is approximately opposite the bore ( 182 b) associated with the pressure compensation opening ( 70 b), a portion ( 204 b) forming a control edge of the ring portion ( 204 b) of the second valve element ( 94 b) in the direction of rotation with respect to the pressure equalization opening ( 70 b) associated bore ( 182 b) offset, but this is closely adjacent, and
wherein to actuate the clutch, the first valve element ( 92 b) is rotatable in relation to the rotational position of the basic state in the direction of rotation, in particular at most approximately up to a rotational position in which the opening of the through bore ( 202 b) of the pressure medium source ( 51 b) assigned Hole ( 184 b) is approximately opposite. 40. Actuating device according to one of claims 32 to 39, characterized in that the recess is preferably a through bore ( 180 b) in the valve housing ( 90 b) running transversely to the direction of movement of the release bearing arrangement, at one end of which the first valve element ( 92 b ) is accessible, in particular protrudes, and at the other end the second valve element ( 94 b) is accessible, in particular protrudes. 41. Actuating device according to claim 40 and according to claim 11, characterized in that from the through hole ( 180 b) in the valve housing ( 90 b) projecting end portion ( 206 b) of the second valve element ( 94 b) has a rigidly coupled bracket ( 226 b) as a coupling element, which acts on the release bearing arrangement or the release bearing arrangement side ( 162 b) of the pressure-medium cylinder arrangement ( 14 b), in particular by spring means ( 238 b) acting on the bracket ( 226 ) and the valve housing ( 90 b), preferably comprising a leg spring ( 238 ) arranged around the end section ( 208 b) and biased against it, wherein a linear movement of the release bearing arrangement or the release bearing arrangement side ( 162 b) of the pressure medium power cylinder arrangement ( 14 b) via the bracket ( 226 b) into a rotary movement of the second valve element ( 94 b) can be implemented. 42. Actuating device according to claim 40 or 41 and according to claim 13, characterized in that the spring-biased piston ( 236 b) of the converter means is part of a cylinder-piston arrangement ( 234 b) separate from the valve elements ( 92 b, 94 b), wherein the piston ( 236 b) is preferably movable in a direction which is essentially transverse to the valve axis (B '), and wherein a linear movement of the piston ( 236 b) via a deflection arrangement acting on the first valve element ( 92 b), in particular toggle lever arrangement ( 230 b, 232 b), can be converted into a rotary movement of the first valve element ( 92 b). 43. Actuating device according to one of claims 1 to 31, characterized in that the first ( 92 d) and the second ( 94 d) valve element are mounted in a recess ( 180 d) of the valve housing ( 90 d), one of the valve elements can be rotated about a valve axis (B '') and the other valve element can be displaced along the valve axis (B ''), one size of the actual size and the reference size being determined by a rotational position and the other size by an axial position of the respective valve element ( 92 d; 94 d) is represented. 44. Actuating device according to claim 43 and according to claim 29, characterized in that the first valve element ( 92 d) has the coaxial to the valve axis (B '') ring section ( 412 d), the second valve element ( 94 d) at least partially radially outside encloses. 45. Actuating device according to claim 43 or 44, characterized in that the along the valve axis (B '') displaceable valve element, in particular the first valve element ( 92 d), is secured against rotation about the valve axis (B ''), or / and that the valve element rotatable about the valve axis (B ''), in particular the second valve element ( 94 d), is secured against displacement along the valve axis (B ''). 46. Actuating device according to one of claims 43 to 45, characterized in
that of the elements - first valve element ( 92 d) and second valve element ( 94 d) - a valve element, in particular the first valve element ( 92 d), at least two holes ( 442 d, 444 d) offset in the circumferential direction and / or in the axial direction , in particular bores, as pressure medium passage openings, and
that the other valve element has at least one elongated hole ( 440 d) cooperating with the holes ( 442 d, 444 d) for realizing the valve control states as a pressure medium passage opening, which extends both in the circumferential direction and in the axial direction, preferably obliquely to an axially parallel one Surface line of the valve element ( 92 d) runs. 47. Actuating device according to claim 46, characterized in that the control valve, in particular the valve housing and / or the first valve element ( 92 d) and / or the second valve element, pressure medium guide means ( 446 d, 448 d), the passage connection for a pressure medium pressure medium passage openings ( 442 d and 48 d; 444 d and 70 d) assigned to one another in pairs in the valve housing ( 90 d) and on the other hand in one of the two valve elements ( 92 d) regardless of the position of this valve element ( 92 d) relative to the valve housing ( 90 d) care. 48. Actuating device according to claim 47, characterized in that the pressure medium guide means at least one in the axial direction and / or circumferential pressure medium guide recess ( 446 d, 448 d) in abutting surface sections of the valve housing, the first valve element ( 92 d) and the second valve element comprise, which has a respective pressure medium passage opening ( 442 d; 444 d) and with the pressure medium passage opening assigned in pairs to this pressure medium passage opening ( 48 d or 70 d) regardless of the position of the respective valve element ( 92 d) in pressure medium passage connection stands. 49. Actuating device according to claim 47 or 48, characterized in that the pressure medium guide means at least one formed in the control valve, at least two elements of valve housing ( 90 s; 90 t), first valve element and second valve element ( 94 s; 94 t) at least partially limited interior space ( 460 s; 460 t), into which the pressure medium passage openings ( 48 s and 440 s; 48 t and 440 t) assigned to each other open regardless of the position of the respective valve element. 50. Actuating device according to one of claims 43 to 49, characterized in that in at least one position range of the two valve elements ( 92 d, 94 d) relative to each other and relative to the Ventilge housing ( 90 d) via exactly two pressure medium passage openings ( 48 d, 430 d) in the valve housing ( 90 d), exactly one pressure medium passage opening ( 442 d) in the first valve element ( 92 d) and exactly one pressure medium passage opening ( 440 d) in the second valve element ( 94 d) a pressure medium connection between the pressure medium source and the pressure medium power cylinder arrangement is manufactured and in at least one other position range of the two valve elements ( 92 d, 94 d) relative to one another and relative to the valve housing ( 90 d) via exactly two pressure medium passage openings ( 70 d, 430 d) in the valve housing ( 90 d ), exactly one pressure medium passage opening ( 444 d) in the first valve element ( 92 d) and exactly one pressure medium passage opening ( 440 d) in the z wide valve element ( 94 ) a pressure medium connection between the pressure medium power cylinder arrangement and the pressure compensation opening ( 70 b) is made. 51. Actuating device according to one of the preceding claims, characterized in that the control valve has biasing means ( 424 d) which bias at least one ( 92 d) of the two valve elements in one direction, preferably in a direction corresponding to a basic state of the actuating device without clutch actuation Position. 52. Actuating device according to one of the preceding claims, characterized in that the second valve element ( 94 d) has at least one section ( 450 d) accessible from outside the valve housing ( 94 d) or a ver connected with this valve element, from the valve housing ( 94 d) lead-out coupling element is provided, the accessible section ( 450 d) or the coupling element being used for movement coupling the second valve element ( 94 d) to the release bearing arrangement or the release bearing arrangement side of the pressure medium power cylinder arrangement. 53. Actuating device according to one of the preceding claims, characterized in that the first valve element ( 92 n; 92 p; 92 q; 92 t) has at least one section accessible from outside the valve housing or a coupling element connected to this valve element and led out of the valve housing ( 480 p, 450 q) is provided, the accessible section or the coupling element serving to move the first valve element according to the command variable. 54. Actuating device according to one of the preceding claims, characterized in that the first valve element ( 92 d) and the second valve element ( 94 d) as cylinder bodies or cylinder hollow bodies which can be inserted into one another, in particular circular cylinder bodies or circular cylinder hollow bodies, are trained. 55. Actuating device according to one of the preceding claims, characterized in that the valve housing ( 90 d) has an inner ( 402 d) and a recess ( 180 d) which receives the valve elements ( 92 d, 94 d), outer ( 400 d) housing part, the inner housing part ( 402 d) preferably having a cylinder section ( 408 d), in particular circular cylinder section, which can be inserted into the valve elements ( 92 d, 94 d). 56. Actuating device according to one of claims 43 to 55, characterized in that the valve element ( 92 d) displaceable along the valve axis (B '') has a pin section which is preferably coaxial to the valve axis (B ''), optionally a polygonal pin section ( 422 d) has, which in an assigned, cross-sectionally adapted opening of a housing section ( 408 d), in particular the inner housing part ( 402 d), is insertable to secure this valve element ( 92 d) against rotation. 57. Actuating device according to one of claims 43 to 56, characterized characterized in that the valve is slidable along the valve axis element and an adjacent housing section tongue and groove means have, which secure this valve element against rotation. 58. Actuating device according to one of claims 43 to 57, characterized in that to limit the range of movement of the valve elements ( 92 d, 94 d) relative to one another and / and to hold the first valve element ( 92 d) in the starting position when the actuating device Assuming the basic state, one ( 92 d) of the two valve elements has a recess ( 452 d), in particular an elongated hole ( 452 d) in the axial and circumferential direction, optionally obliquely to an axially parallel allelevel line of the valve element, into which the preferably as a coupling element Serving engagement section ( 450 d) of the other valve element ( 94 d) engages. 59. Actuating device according to claim 58, characterized in that the course of the recess ( 452 d) is adapted to the course of the elongated hole serving as a pressure medium passage opening ( 440 d), on the one hand to provide a defined response of the actuating device regardless of any clutch wear or / and to keep a clutch travel-induced free travel at least as small as possible, and on the other hand to provide a range of movement of the valve elements ( 92 d, 94 d) required for realizing the control states relative to one another. 60. Actuating device according to one of the preceding claims, characterized in that abutting surface sections of the valve housing ( 90 b; 90 d), the first ( 92 b; 92 d) and the second ( 94 b; 94 d) valve element as a sealing or / and sliding surfaces are formed, or / and sealing elements ( 216 b, 218 b; 426 d, 428 d) act sealingly between them. 61. Actuating device according to one of the preceding claims, characterized in that the control valve (42) is disposed within the housing bell (12), but machine in with of the internal combustion and connected to the transmission housing bell (12) forth accessible from the outside, in particular expandable. 62. Actuating device according to one of the preceding claims, characterized in that the disengaging direction of the pressure medium power cylinder arrangement ( 14 ) and the disengaging direction of the friction clutch are essentially parallel to one another, preferably the coupling axis (A) and the power cylinder arrangement axis (A) essentially coinciding . 63. Actuating device according to one of the preceding claims, characterized in that the valve axis (B '; B' ') and the Kraftzylin the arrangement axis (A) have no point in common.   64. Actuating device according to claim 63, characterized in that the valve axis and the power cylinder assembly axis to each other are essentially parallel. 65. Actuating device according to claim 63, characterized in that the valve axis (B ') and the power cylinder arrangement axis (A) in Projection onto a plane essentially parallel to both axes are substantially orthogonal to each other. 66. Actuating device according to one of the preceding claims, characterized in that the control valve ( 42 ) on the pressure medium power cylinder arrangement ( 14 ) is in particular detachably attached. 67. Actuating device according to claim 66, characterized in that a control valve assembly ( 40 ) comprising the control valve ( 42 ) relative to a power cylinder assembly ( 14 ) comprising the power cylinder assembly ( 14 ) in a relative to the power cylinder assembly axis ( A) is offset in the radial direction and is detachably attached to a radially outer portion of the power cylinder assembly ( 14 ). 68. Actuating device according to claim 67, characterized in that the control valve assembly ( 40 ) after loosening any between the two units effective fastening or / and coupling means, which are preferably accessible from at least one radial direction substantially corresponding radial direction , of the power cylinder assembly ( 14 ) is substantially removable in the radial direction. 69. Actuating device according to one of the preceding claims, characterized in that the pressure medium is a pneumatic Pressure is.   70. Control valve, in particular for an actuating device according to a of the preceding claims, with the control valve features at least one of the preceding claims, in any case the Claim 23.