DE102013211226A1 - Operating device for e.g. friction clutch of motor car, has actuator comprising piston, which is moved in actuator direction, where actuator actuates master cylinders by movement in actuator direction and moves master cylinders - Google Patents

Abstract

The device (1) has a set of hydraulic systems (4, 8) with master cylinders (5, 9), which are connected with slave cylinders (6, 10) over hydraulic connection units (7, 11). An actuator (12) comprises a piston (13), which is moved in actuator directions (14, 15), where the actuator actuates the master cylinders by the movement in the actuator directions. The actuator moves the master cylinders in the actuator directions, and a throttle is fixed in each hydraulic connection unit for throttling flow of hydraulic fluid (20) from the slave cylinders to the master cylinders. Independent claims are also included for the following: (1) a method for operating clutch systems by an operating device (2) a friction clutch for a motor car.

Description

The invention relates to an actuator for two clutch systems, in particular for dual clutches, in which the two clutch systems are connected in parallel to each other, and can be switched preferably matched.

The two clutch systems are often actuated in the prior art by a hydraulic system. Here, a respective slave cylinder is used for each clutch system, which is actuated via a common master cylinder. That is, the slave cylinder has an actuating piston, by means of which usually a disc spring is released, so that the corresponding clutch system is no longer connected frictionally and then (almost) no torque is transmitted. Is one of the two clutch systems connected, that is, one of the slave cylinder pressurized and thus deflected the actuating piston, and should now be switched to the other clutch system and the first are released, the master cylinder is connected to the second slave cylinder and switched for the first Slave cylinder allows a drain in an overflow or in a drain tank. Thus, the first clutch system dissolves independently. The switching principle is in the 1 shown and explained in more detail in the description of the figures.

The disadvantage here is that during the drainage of the hydraulic fluid due to the pressure decrease, this can foam and continue the amount of hydraulic fluid or the pressure in the hydraulic system must be readjusted after each release and before each new operation of the slave cylinder. Furthermore, the Einregelungsvorgang requires a certain amount of time, so that an immediate downshift of the previous slave cylinder is limited in time. This can be disadvantageous, in particular in the case of a faulty circuit which must be interrupted and reversed during the changeover.

On this basis, the present invention has the object, at least partially overcome the known from the prior art disadvantages.

The object is solved by the features of the independent claims. Advantageous developments are the subject of the dependent claims.

• – ein erstes hydraulisches System mit einem ersten Geberzylinder, der mit einem ersten Nehmerzylinder über eine erste hydraulische Verbindung verbunden ist;
• – ein zweites hydraulisches System mit einem zweiten Geberzylinder, der mit einem zweiten Nehmerzylinder über eine zweite hydraulische Verbindung verbunden ist;
• – einen Aktor, der einen Kolben aufweist, welcher in einer ersten Aktorrichtung und in einer zweiten Aktorrichttung bewegbar ist und mittels einer Bewegung in die erste Aktorrichtung den ersten Geberzylinder betätigt und mittels einer Bewegung in die zweite Aktorrichtung den zweiten Geberzylinder betätigt.

The invention relates to an actuating device for two coupling systems, wherein the actuating device has at least the following components:

• A first hydraulic system having a first master cylinder connected to a first slave cylinder via a first hydraulic connection;
• A second hydraulic system having a second master cylinder connected to a second slave cylinder via a second hydraulic connection;
• - An actuator having a piston which is movable in a first actuator and in a second Aktorrichttung and actuated by means of a movement in the first actuator, the first master cylinder and actuated by means of a movement in the second actuator, the second master cylinder.

An actuating device for two clutch systems is set up to switch a respective clutch system, for example in the case of a friction clutch to press friction partners against one another or to separate the pressed friction partners from one another. The two coupling systems are preferably part of a double clutch. For each of the two clutch systems, the actuator has a hydraulic system. With this hydraulic system, the clutch systems are each separately switchable. The hydraulic systems each have a master cylinder and a slave cylinder connected via a hydraulic connection. The master cylinder is moved via an actuator, so that the hydraulic fluid between the master cylinder and the slave cylinder caused as a result of an increase in pressure or pressure reduction movement in the slave cylinder. It should be noted that here the hydraulic connection is not exclusively a physical line, but rather the connection between the master cylinder and the slave cylinder, which can run through switching elements in different lines. The actuator is, for example, an electric motor with a spindle drive and a piston. By a method of the piston on the spindle drive the respective master cylinder can be actuated. Now, if the piston is moved in a first actuator, the first master cylinder is actuated. If the piston is moved from the zero position in the second actuator, the second master cylinder is actuated. In this case, the piston is advantageously arranged centrally in the zero position between the master cylinders, so that an actuation of the one master cylinder means at the same time a release of the other master cylinder.

This makes it possible to operate in a normal operating state, for example switching between the two clutch systems, without an overflow or drain tank. Also allows such an arrangement that the slave cylinder tuned to each actuate the clutch systems, that is, solve if the other should be connected and connect while the other is solved.

In a further advantageous embodiment of the actuator, the actuator moves the master cylinder only in one direction and the master cylinder are free in the opposite direction.

In this advantageous arrangement, the master cylinder are only connected on one side with the actuator, so that they are only pushed, for example, but not withdrawn or, conversely, only pulled but not pushed. This has the advantage that the actuator always acts only against a master cylinder and thus does not need more power than is necessary in an actuator of the prior art. Another advantage is that the donor cylinder to be solved can solve slower than a necessary engagement movement of the other master cylinder.

In a further advantageous embodiment of the actuating device, a check valve is further provided in a hydraulic connection, with which the hydraulic connection can be blocked.

By using a check valve, it is possible to block a return flow from the slave cylinder to the master cylinder. As a result, the actuator does not have to apply a long-term holding force and can be made smaller, and in particular cool down after each switching operation. Advantageously, in each case a check valve is provided in the two slave cylinders or in the two hydraulic connections (symmetrical). Advantageously, the pressure release is controlled in the switched slave cylinder via the respective check valve (discrete).

In a further advantageous embodiment of the actuating device, a check valve and a switching valve are provided, wherein the check valve in the first hydraulic connection or in the second hydraulic connection can be switched by the switching valve.

By arranging a switching valve, a common shut-off valve can be used for both hydraulic connections. Thus, only one control device for a check valve is necessary. Nevertheless, the respective hydraulic connection can be provided with a constant liquid filling via the switching valve. Thus, no replenishment of hydraulic fluid is necessary.

In a further advantageous embodiment of the actuating device, a throttle for throttling the outflowing hydraulic fluid from the slave cylinder to the master cylinder is provided in at least one hydraulic connection.

By forming a throttle during the outflow from the slave cylinder to the master cylinder, a drainage of the hydraulic fluid and thus the pressure reduction in the slave cylinder can be slowed down. Thus, the pressure reduction does not have to be regulated via a shut-off valve or the actuator.

• a) Halten des einen Nehmerzylinders, so dass ein Kupplungssystem geschlossen ist;
• b) Betätigen des anderen Geberzylinders, der den anderen Nehmerzylinder hydraulisch betätigt;
• c) nach Schritt b) Lösen des gehaltenen Nehmerzylinders, wobei dieser Nehmerzylinder dabei den zugehörigen Geberzylinder zurückstellt und die Menge der hydraulischen Flüssigkeit in diesem hydraulischen Systemen konstant bleibt; und
• d) nach Schritt c) Halten des anderen Nehmerzylinders, so dass das andere Kupplungssystem geschlossen ist.

According to a further aspect of the invention, a method is also proposed for actuating a first clutch system and a second clutch system by means of an actuating device as described above, the method having at least the following steps:

• a) holding the one slave cylinder, so that a coupling system is closed;
• b) actuating the other master cylinder, which hydraulically actuates the other slave cylinder;
• c) after step b) releasing the held slave cylinder, said slave cylinder thereby restoring the associated master cylinder and the amount of hydraulic fluid in these hydraulic systems remains constant; and
• d) after step c) holding the other slave cylinder, so that the other coupling system is closed.

In the method proposed here, the two master cylinders are coordinated with each other so that the release of the one clutch system takes place while the engagement of the other clutch system is made via the other slave cylinder. Here, the amount in each hydraulic system consisting of a slave cylinder, a hydraulic line and a master cylinder remains constant. By means of this method, it is possible to instantly reverse a switching operation. In particular, no refilling operations need to be performed and, normally, no hydraulic fluid needs to be drained, with undesirable bubbles trapped.

In a further advantageous embodiment of the method, at least one of the slave cylinder is held via a check valve.

By using a check valve, the actuator can be relieved; because this can be used exclusively for the switching operation and be completely relieved in the hold state. Thus, a smaller actuator can be used and the actuator can cool in the hold phase. In another aspect, a controlled release of the pressure in the slave cylinder can be made via the check valve, while regardless of the actuator actuates the other master cylinder or another check valve the Holding force for the other slave cylinder guaranteed. By holding the slave cylinder switched or locking the hydraulic line is ensured that one moment is still transferable, while the other clutch system is switched. Thus, errors in the circuit can be compensated. Also, a switch back over this can be accelerated, because the pressure reduction takes place only at the last necessary time. In particular, the check valve may be arranged so that it opens in case of failure of the energization, for example by acting against a spring force, and thus ensures that no torque is transmitted in case of failure.

In a further advantageous embodiment of the method, the first hydraulic system and the second hydraulic system have a common check valve and a switching valve, wherein the switching valve switches the check valve in the first hydraulic connection or in the second hydraulic connection.

By means of a common check valve and a switching valve, which switches the check valve in the first hydraulic line or in the second hydraulic line, a single check valve and also a single control can be used for this check valve. In particular, only one device for generating the necessary blocking force is necessary.

In a further advantageous embodiment of the method, both hydraulic connections each have a check valve, and for changing the switched slave cylinder locks the holding check valve until the actuating piston of the other slave cylinder has moved out so far that via the associated coupling system, a moment is transferable, and then the holding blocking valve opens in response to the increasing torque transmission.

According to a further aspect of the invention, a friction clutch for motor vehicles is proposed, which has a first clutch system and a second clutch system, via which an input shaft with a first output shaft and a second output shaft is releasably connectable, and further comprising an actuating device, and in particular for carrying out a Method is set up according to the above description.

The friction clutch proposed here is in particular a double clutch for motor vehicles, which is used for driving the motor vehicle. By way of an input shaft, which is connected, for example, to a drive unit, for example an internal combustion engine or an electric motor, a torque is transferably transferrable to a first or a second output shaft. In this case, the first clutch system establishes a releasable frictional connection between the input shaft and the first output shaft, and the second clutch system produces a releasable frictional connection between the input shaft and the second output shaft. By using the above-described actuator, the switching from a first output shaft to a second output shaft and backward can be performed almost arbitrarily fast. In particular, there is no risk of bubble entrapment in a hydraulic system. In particular, by the execution of a method according to the above description, the friction clutch can be switched very flexible and efficient.

The features listed individually in the claims can be combined with one another in any technologically meaningful manner and can be supplemented by explanatory facts from the description and details from the figures, wherein further embodiments of the invention are shown.

The invention and the technical environment will be explained in more detail with reference to FIGS. The figures show particularly preferred embodiments, to which the invention is not limited. In particular, it should be noted that the figures and in particular the illustrated proportions are only schematic. Show it:

1 a known as an actuator,

2 an actuator with separate master cylinders,

3 an actuator with check valves,

4 an actuator with switching valve and check valve,

5 : an actuator with master cylinders in zero position,

6 : an actuator with master cylinders in a first actuator,

7 : an actuator in an intermediate state in a second actuator,

8th : an actuator in a final state in second actuator,

9 : a friction clutch with actuator, and

10 : a motor vehicle with friction clutch.

1 shows an assumed adopted actuator 40 in which, to clarify the differences, the same components with the same reference numerals as in the actuator 1 (not shown) are designated. Here is a master cylinder 5 provided, both slave cylinders 6 . 10 actuated. The slave cylinder 6 . 10 are each via a hydraulic connection 7 . 11 with the master cylinder 5 connected. For switching is a switching valve 18 provided, which is the hydraulic connection 7 directly with the master cylinder 5 can connect or via a switching valve 16 and an overflow 26 , The master cylinder 5 with the hydraulic fluid 20 is about an actor 12 actuated.

2 shows an actuator 1 with a first hydraulic system 4 and a second hydraulic system 8th , each one a first master cylinder 5 , a first slave cylinder 6 and a first hydraulic connection 7 has or a second master cylinder 9 , a second slave cylinder 10 and a second hydraulic connection 11 , The master cylinder 5 . 9 be about a piston 13 in a first actuator 14 or a second actuator 15 actuated. The piston 13 is here via an actor 12 , for example, driven by a spindle drive. Again, there is the possibility of connecting to an overflow 26 in the normal case but not the hydraulic fluid 20 hydraulic systems 4 . 8th is directed.

In 3 is a similar arrangement as in 2 shown here, further here is a first check valve 16 in the first hydraulic connection 7 and a second shut-off valve 17 in the second hydraulic connection 11 is provided. These can hold the respective slave cylinder 6 and 10 be used. In the event of a power failure, the switching valves are used for safety aspects 16 . 17 openly. Furthermore, it can be seen that the piston 13 in the second actuator 15 is moved, the opposite direction for the first master cylinder 5 equivalent. In this movement is the master cylinder 5 free.

Also in 4 is a similar arrangement as in 2 and 3 shown, here only one check valve 16 is provided, which through the switching valve 18 either in the first hydraulic connection 7 is switched or (as shown here) in the second hydraulic connection 11 is switched.

In 5 is an actor 12 with a first master cylinder 5 and a second master cylinder 9 shown over a piston 13 are driven. Two side outlets indicate the first hydraulic connection 7 and the second hydraulic connection 11 at. In the situation shown here, neither of the two master cylinder 5 . 9 actuated.

In 6 is the arrangement as in 5 shown, with the actuator 12 in the first actuator 14 is pressed. This will be the first master cylinder 5 so actuated that the pressure over the first hydraulic connection 7 is increased, which is indicated here by an arrow. It should be noted that the second master cylinder 9 not operated.

In 7 will the arrangement, from the location as they are in 6 is shown in the second actuator 15 or opposite direction actuated, it can be seen here that the first master cylinder 5 is motionless in its opposite direction and not a forced movement by the piston 13 describes.

In 8th is the arrangement as in 7 shown, in which case the second master cylinder 9 generates the maximum pressure, which is indicated by an arrow and the first master cylinder 5 generates the minimum pressure, which is also indicated here by an arrow.

In 9 is a friction clutch 21 shown a first slave cylinder 6 and a second slave cylinder 10 has, over which a first actuating piston 27 and a second actuating piston 28 are driven. The first actuating piston 27 acts on a first operating lever 34 who made the first pressure plate 29 against the first friction disc 31 and the central pier 33 pressed. Above that is a moment around the axis 37 from the input shaft 23 over the clutch housing 36 on the first pressure plate 29 and the central pier 33 by friction on the first friction disc 31 and the first output shaft 24 transfer. The second pressure plate 30 is from the second friction disc 32 and the central pier 33 solved, so no torque over the friction disc 32 on the second output shaft 25 is transmitted. On the first slave cylinder 6 is a first hydraulic connection 7 connected, which is a choke 19 having. On the second slave cylinder 10 is a second hydraulic connection 11 connected.

In 10 is a motor vehicle 22 shown in which a drive unit 38 via a friction clutch 21 with a purely schematically illustrated drive train 39 connected is.

With the actuating device proposed here for two clutch systems, it is possible to switch the clutch systems without an interim pressure reduction and possible bubble entrapment. In particular, can be switched back without as required in the prior art dead times.

LIST OF REFERENCE NUMBERS

1

 actuator

2

 first coupling system

3

 second coupling system

4

 first hydraulic system

5

 first master cylinder

6

 first slave cylinder

7

 first hydraulic connection

8th

 second hydraulic system

9

 second master cylinder

10

 second slave cylinder

11

 second hydraulic connection

12

 actuator

13

 piston

14

 first actuator

15

 second actuator

16

 first shut-off valve

17

 second shut-off valve

18

 switching valve

19

 throttle

20

 hydraulic fluid

21

 friction clutch

22

 motor vehicle

23

 input shaft

24

 first output shaft

25

 second output shaft

26

 overflow

27

 first actuating piston

28

 second actuating piston

29

 first pressure plate

30

 second pressure plate

31

 first friction disc

32

 second friction disc

33

 central web

34

 first operating lever

35

 second operating lever

36

 clutch housing

37

 axis

38

 drive unit

39

 powertrain

40

 as assumed assumed actuator

Claims (10)

Actuating device ( 1 ) for two coupling systems ( 2 . 3 ), comprising at least the following components: - a first hydraulic system ( 4 ) with a first master cylinder ( 5 ), with a first slave cylinder ( 6 ) via a first hydraulic connection ( 7 ) connected is; A second hydraulic system ( 8th ) with a second master cylinder ( 9 ), with a second slave cylinder ( 10 ) via a second hydraulic connection ( 11 ) connected is; - an actor ( 12 ), which has a piston ( 13 ), which in a first actuator ( 14 ) and in a second actuator ( 15 ) is movable and by means of a movement in the first actuator ( 14 ) the first master cylinder ( 5 ) and by means of a movement in the second actuator ( 15 ) the second master cylinder ( 9 ). Actuating device ( 1 ) according to claim 1, wherein the actuator ( 12 ) the master cylinder ( 5 . 9 ) only in one direction ( 14 . 15 ) and the master cylinder ( 5 . 9 ) in the opposite direction ( 15 . 14 ) are free. Actuating device ( 1 ) according to claim 1 or 2, further comprising a check valve ( 16 . 17 ) in a hydraulic connection ( 7 . 11 ) is provided, with which the hydraulic connection ( 7 . 11 ) is lockable. Actuating device ( 1 ) according to one of the preceding claims, wherein a check valve ( 16 ) and a switching valve ( 18 ) are provided, wherein by the switching valve ( 18 ) the check valve ( 16 ) in the first hydraulic connection ( 7 ) or in the second hydraulic connection ( 11 ) is switchable. Actuating device ( 1 ) according to one of the preceding claims, wherein in at least one hydraulic connection ( 7 . 11 ) a throttle ( 19 ) for throttling draining hydraulic fluid ( 20 ) from the slave cylinder ( 6 . 10 ) to the master cylinder ( 5 . 9 ) is provided. Method for actuating a first coupling system ( 2 ) and a second coupling system ( 3 ) by means of an actuating device ( 1 ) according to one of the preceding claims, which comprises at least the following steps: a) holding the one slave cylinder ( 6 . 10 ), so that a coupling system ( 2 . 3 ) closed is; b) Actuating the other master cylinder ( 9 . 5 ), the other slave cylinder ( 10 . 6 ) hydraulically actuated; c) after step b) releasing the held slave cylinder ( 6 . 10 ), this slave cylinder ( 6 . 10 ) while the associated master cylinder ( 5 . 9 ) and the amount of hydraulic fluid ( 20 ) in this hydraulic systems ( 4 . 8th ) remains constant; and d) after step c) holding the other slave cylinder ( 10 . 6 ), so that the other coupling system ( 3 . 2 ) closed is. Method according to claim 6, wherein at least one of the slave cylinders ( 6 . 10 ) via a check valve ( 16 . 17 ) is held. Method according to claim 6 or 7, wherein the first hydraulic system ( 4 ) and the second hydraulic system ( 8th ) a common shut-off valve ( 16 ) and a switching valve ( 18 ), wherein the switching valve ( 18 ) the check valve ( 16 ) in the first hydraulic connection ( 7 ) or in the second hydraulic connection ( 11 ) switches. Method according to claim 6 or 7, wherein both hydraulic connections ( 7 . 11 ) each a check valve ( 16 . 17 ), and for changing the switched slave cylinder ( 6 . 10 ) the holding check valve ( 16 . 17 ) locks until the actuating piston ( 28 ) of the other slave cylinder ( 10 . 6 ) far enough that via the associated coupling system ( 3 . 2 ) a moment is transferable, and then the holding check valve ( 16 . 17 ) tuned to the increasing torque transmission throttled opens. Friction clutch ( 21 ) for motor vehicles ( 22 ), comprising a first coupling system ( 2 ) and a second coupling system ( 3 ) via which an input shaft ( 23 ) with a first output shaft ( 24 ) or a second output shaft ( 25 ) is releasably connectable, comprising an actuating device ( 1 ) according to one of claims 1 to 5, and in particular for carrying out a method according to one of claims 6 to 9.

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