DE102014206985A1 - clutch actuator - Google Patents

Abstract

The invention relates to a clutch actuator for actuating a friction clutch rotating around an axis of rotation with an electric servomotor arranged around the axis of rotation with a rotor driven around the axis of rotation, an actuator converting a linear movement into an axial movement for the axial displacement of a lever element of the friction clutch depending on a rotary drive of the servomotor as well as a two-stage planetary gear that automatically switches between the actuator and the servomotor depending on a load of the clutch actuator with a sun gear rotationally locked to the rotor, a ring gear fixed to the housing by means of a freewheel, planet gears meshing between sun gear and ring gear, rotatably received on a planet carrier and a sun gear and planet carrier switchable connecting clutch. For simple and reliable switching of the clutch, it has a switching element that separates a connection between the sun gear and the planetary carrier as a function of the load through axial displacement and a restoring element that restores the connection from a stationary to a rotated state of the rotor depending on a mass inertia.

Description

The invention relates to a clutch actuator for actuating a friction clutch rotating about an axis of rotation with an electric servomotor arranged around the rotational axis with a rotor driven about the axis of rotation, an actuator for axial displacement of a lever element of the friction clutch depending on a rotary drive of the servomotor and a two-stage planetary gearbox automatically coupled between actuator and servomotor depending on a load of the clutch actuator with a sun gear rotatably coupled to the rotor, a ring gear fixed to the housing by means of a freewheel, intermeshing between sun gear and ring gear, planetary gears rotatably received on a planetary carrier, and a sun gear and planet carrier switchable connecting clutch.

Clutch actuators are used to actuate friction clutches in drive trains of motor vehicles. Here, the arranged around an axis of rotation friction clutch is actuated by means of an axial displacement of a lever element depending on the design of the friction clutch. A by means of a plate spring designed as a lever element in the non-actuated state closed friction clutch can be raised or pushed coaxially to the axis of rotation of the disc spring tips, while a non-actuated state open friction clutch is pressed or pulled, for example by means of lever tips a lever spring. Two such friction clutches can be combined to form a double clutch, so that two separate or combined to form a unit clutch actuators each actuate a friction clutch.

Generic clutch actuators are driven by an electric servo motor, which is controlled by a control unit so that a desired torque to be transmitted is controlled quickly and reproducibly. Examples of electric servomotor provided clutch actuators are from the documents DE 10 2008 013 054 A1 and DE 10 2004 009 832 A1 known. Here, in each case a rotor axis of the servomotor is arranged substantially perpendicular to the axis of rotation of the friction clutch. For converting the rotational movement of the rotor of the servomotor into a linear movement, a corresponding transmission is provided. In this case, different forces are to be applied via an actuation path of the friction clutch depending on the clutch position, so that the servomotor must be designed for the maximum force. Furthermore build actuators with low speeds at the required power comparatively large, so that optionally high-speed servo motors are used in conjunction with a reduction gear.

The object of the invention is the development of a clutch actuator with a servomotor with reduction gear in the form of a multi-stage planetary gear with advantageous utilization of the available space at low power of the servo motor.

An advantageous Kupplungsaktor the not previously published, hereby incorporated in full content instead of a purely formal copy function whose contents German Patent Application no , 10 2013 207 069.1 has a clutch actuator for actuating a friction clutch rotating about an axis of rotation with an electric servo motor having a rotor rotating about a rotor axis, and an actuator for axially displacing a lever element of the friction clutch with a reduction gear and a transmission for converting a rotational movement of the servo motor into an axial displacement movement; wherein the reduction gear is formed of a driven about the axis of rotation of the friction clutch, driven by the servo motor and the transmission for converting a rotational movement of the servo motor in an axial displacement movement driving epicyclic gear. Due to the arrangement of the planetary gear about the axis of rotation can be saved radially outward space. Due to the reduction of the planetary gear, a low-power, high-speed servomotor can be used.

In addition, the proposed clutch actuator for actuating a rotating about a rotational axis friction clutch arranged around the axis of rotation electric servomotor having a rotor driven about the axis of rotation, a linear motion in an axial movement converts actuator, such as a spindle drive for axial displacement of a lever element of the friction clutch depending a rotary drive of the servomotor and an actuator and actuator depending on a load of the clutch actuator automatically switching two-stage planetary gear with a rotatably coupled to the rotor sun gear, a housed by a freewheel housing fixed ring gear, meshing between the sun and ring gear, rotatably received on a planet carrier planetary gears and a sun gear and planet carrier switchable interconnecting clutch on. Here, the clutch on a load-dependent axial displacement by a connection between the sun and planet carrier separating switching element and a dependent on an inertia in the case of a stationary in a twisted state of the rotor the connection restoring restoring member.

The switching member may be arranged distributed over the circumference, in a first axial position a positive connection between the sun gear and planetary and releasing in a second axial position releasing first balls, the first balls axially displacing guide ring and circumferentially distributed, axially biased, have radially displaceable, a load-dependent axial displacement of the guide ring controlling second balls.

In the return member is provided in a preferred manner from a rotor fixedly assigned to the drive part and a rotatable relative thereto and the guide ring axially applied inertial member with an axially between the drive part and the inertial part in the direction of rotation of the rotor an axial distance of this widening ramp means. In this case, at least one energy store can be arranged between the inertia part and the drive part in the circumferential direction against the widening effect of the ramp device. Furthermore, an axially effective energy store can be provided between the drive part and a tensioning the second balls clamping part.

The function of the clutch actuator and a method for its control includes, in an open state of a friction clutch pressed by the actuator, a positive connection of sun gear and planet carrier with each other by means of the clutch. At the beginning of torque transmission of the friction clutch, the clutch sun gear and planet carrier releases. At the opening of the friction clutch completely zurückverlagertem actuator planet carrier and sun gear remain unlocked. In a rotation of the rotor with fully backward displaced actuator axial displacement of the guide ring of the clutch for connection of sun gear and planet gears by means of a rotation of the inertial member relative to the drive member is provided.

The invention is based on the in the 1 to 8th illustrated embodiment illustrated. Showing:

1 a diagram of the actuation force against a actuation path,

2 a schematic representation of a two-stage planetary gear,

3 a section through a double clutch with a clutch actuator for actuating one of the friction clutches of these,

4 a section through a clutch actuator on the two-stage planetary gear perpendicular to the axis of rotation,

5 a longitudinal section through the clutch actuator of 4 .

6 the clutch actuator of 4 and 5 in a truncated 3D view,

7 a functional representation of the clutch actuator of 4 to 6 in longitudinal section
and

8th a functional representation of the clutch actuator of 4 to 6 in view.

The 1 shows the diagram 100 with the curve 101 showing a typical actuation force F _B over an actuation travel s of a depressed friction clutch. The curve 101 points in the area of the borderline 102 a more or less strong kink on the curve 101 in the two curve areas 103 . 104 divided. The curve area 103 is assigned to a path range in which a lever element of the friction clutch is shifted from a basic position without actuator actuation in the actuation path s = 0 with a small increase in force in a ready position. The curve area 104 is assigned to a path range in which the friction clutch increasingly torque transfers to a maximum transmissible torque by friction linings between a counter-pressure plate and the lever element against this tensioned pressure plate are braced and thus a high increase in force is necessary. The proposed clutch actuator takes into account the two-stage planetary gear, by in the curve area 103 a small reduction of a servomotor and in the curve area 104 a larger reduction is switched independently. In this way, the curve area 103 quickly bridged and in the curve area 104 a high actuation force or a large drive torque of a comparatively small-sized, fast-rotating servomotor can be achieved. It is understood that the curve 101 represents an average value of curves and curve areas that diffuse depending on different tolerances, with corresponding tolerance ranges such as energy ranges.

2 shows a schematic diagram of the automatic switching planetary gear 10 with the clutch 12 , The planetary gear 10 is designed as a plus gear. The clutch 12 locks up to a predetermined drive torque M _ON the planet carrier 14 relative to the driven by the servo motor, not shown sun gear 13 so that on the planet carrier 14 rotatable recorded planet gears 15 the ring gear 16 drive without rotation and the drive torque M _IN equal to the output torque M _{OUT of} the planetary gear 10 at the same speed of sun gear 13 and ring gear 16 is. Here is the between a housing component and the ring gear 17 arranged freewheel 18 overrun. Is due to a transition of the curve 101 of the 1 from the curve area 103 in the curve area 104 the load at the output of the planetary gear 10 increases, the moment of the clutch becomes 12 overcome, so that the planet carrier 14 opposite the sun wheel 13 twisted and the rotating planet gears 15 setting a reduction gear, the ring gear 16 drive. Here, the freewheel locks 18 the ring gear 17 ,

3 shows the upper half of a partial section of the double clutch 2 along the axis of rotation d with the two friction clutches 3 . 4 , The example of the friction clutch 3 that over the tie rod 5 by means of the lever element 6 is tightened, function and arrangement of the clutch actuator 1 shown. In the same way, the means of the lever element 7 pressed friction clutch 4 from a clutch actuator 1 essentially corresponding axially adjacent or radially arranged over this clutch actuator can be actuated. In the embodiment shown, the components of the clutch actuator 1 arranged coaxially about the axis of rotation. The servomotor 8th drives the planetary gear 10 at. This drives the actuator 9 for the conversion of the rotary motion of the servomotor 8th and thus the planetary gear 10 in a linear actuation movement. The actuator 9 is in the embodiment shown as a ball screw 20 with the planetary gear 10 connected spindle cylinder 19 and the lever element 6 acting actuating bearing 22 carrying actuating cylinder 21 educated.

The 4 to 6 show the structurally designed clutch actuator 1 with the planetary gear 10 , the shift clutch 12 and the actuator 9 for converting the rotational movement of the servo motor, not shown, into an axial actuating movement.

The 4 shows that as a planetary gear 10 in section at the axial height of the freewheel 18 , The freewheel 18 takes the ring gear 17 the first gear stage of the planetary gear 10 on. The ring gear 16 the second gear stage is axially behind the ring gear 17 arranged and drives the gearbox to convert the rotational movement in a linear motion. The planet carrier 14 takes those with both ring gears 16 . 17 and the sun wheel 13 meshing planetary gears 15 on. The sun wheel 13 is by means of the warehouse 23 rotatable on the bearing sleeve 24 arranged and is rotationally driven by the servomotor.

The 5 and 6 show the coaxially about the axis of rotation d of a friction clutch clutch actuator arranged 1 in longitudinal section along the axis of rotation d or in truncated 3D representation. That on the bearing sleeve 24 rotatably received sun gear 13 is by means of the non-rotatably connected to this drive part 25 rotationally driven by the servomotor, not shown. The drive part 25 takes by means of the warehouse 26 the planet carrier 14 rotatable on. The clutch 12 is engaged at small moments. This engages with the sun gear 13 or the drive part 25 connected guide ring 40 by axial approaches 41 rotationally engaged in corresponding recesses 42 of the planet carrier 14 by means of interposed first distributed over the circumference, only partially visible balls 43 axially in a rolling contact. As the moment increases, the on the Rampenwalzeinrichtung 44 with the second balls distributed over the circumference 31 - According to a torque sensor - mounted guide ring 40 against the action of the axially effective energy store 32 , here a compression spring, axially under radial displacement of the second balls 31 shifted to the inside, until finally the positive connection between the guide ring 40 and planet carrier 14 disconnected, the clutch 12 so it is opened. Due to the profiling of the ramp rolling device 44 remains the clutch 12 open and is actively closed again after completion of the operation of the friction clutch before the next operation. This is on the drive part 25 by means of the ramp device 45 limited axially and rotatably displaced recorded, for example, annular trained inertial member 46 provided the guide ring 40 at the onset of rotation by means of the drive part 25 back in the planet carrier 14 positively engages. Will the drive part 25 spin-accelerated, remains the inertia part 46 due to its mass briefly stand in the direction of rotation and is at the ramp device 45 axially displaced and pushes the lugs 41 of the guide ring 40 axially in the recesses 42 of the planet carrier 14 and thus restores the positive connection between them.

Like from the 5 and 6 continues to show, the transfer takes place in the sun 13 registered moments on the planet carrier 14 rotatably received planet gears 15 on the two ring gears 16 . 17 , When due to effective clutch 12 standing planet carrier 14 rotate when driving the sun gear 13 the ring gears 16 . 17 at the same speed. Here, the between housing and ring gear 17 effective freewheel 18 overrun. With open clutch 12 turns the planet carrier 14 across from the sun wheel 13 , To reverse the ring gear 17 To prevent the freewheel locks 18 and forces the planet wheels 15 in a rotational movement, so that the ring gear 16 is rotated. In the embodiment shown, the ring gear 16 in one piece with the spindle cylinder 19 of the actuator 9 in the form of the ball screw 20 educated. About the rotation of the spindle cylinder 19 and in threads of the spindle cylinder 19 and the actuating cylinder 21 rolling balls 34 is the in the bearing sleeve 24 by means of a torque arm, not shown, rotatably supported actuating cylinder 21 shifted axially. The actuating cylinder 21 takes one piece or as shown here separately formed the outer ring 38 of the actuating bearing 22 for rotational decoupling of the clutch actuator 1 opposite the lever element 6 ( 3 ) on.

The 7 and 8th show in longitudinal section or in view the function of a simplified clutch actuator 1 with the clutch 12 of the 5 and 6 in a schematic representation. In the functional presentation drives the servomotor 8th the rotor 30 and on this fixed drive part 25 at. The planet carrier 14 and the guide ring 40 form with the first balls 43 the positive connection between the sun gear 13 and planet carrier 14 , The ramp rolling device 44 , the second balls 31 and the axially between the Rampenwalzeinrichtung 44 and the drive part 25 preloaded energy stores control the positive connection of the clutch 12 by adding the second balls 31 over the ramp rolling device 44 that by means of energy storage 32 preloaded control part 48 shift axially. As a result, the balls are shifting 31 radially inward, leaving the guide ring 40 axially by means of ramps 33 arranged first balls 43 from the planet carrier 14 is spaced and the form fit between them is overridden. The clutch 12 remains solved until it is actively closed again. This is done by means of the inertial part 46 by means of the ramp device 45 on the drive part 25 is created. Is before driving the friction clutch, the drive part 25 rotated, the inertia part remains 46 in the direction of rotation due to its inertial mass short-term stand and is by the ramp device 45 axially displaced so that this the guide ring 40 axially displaced and thereby the positive connection of the clutch 12 restores. Between inertia part 46 and drive part 25 can return springs 49 for returning the inertia part 46 along the ramp device 45 be provided. This form guide ring 40 , first and second balls 31 . 43 , the control part 48 with the ramp rolling device 44 and the energy storage 32 the switching element 27 and the drive part 25 with the inertia part and the ramp device 45 optionally with the return springs 49 the return member 28 the clutch 12 ,

LIST OF REFERENCE NUMBERS

1

 clutch actuator

2

 Double coupling

3

 friction clutch

4

 friction clutch

5

 tie rods

6

 lever member

7

 lever member

8th

 servomotor

9

 actuator

10

 planetary gear

12

 clutch

13

 sun

14

 planet carrier

15

 planet

16

 ring gear

17

 ring gear

18

 freewheel

19

 spindle cylinder

20

 Ball Screw

21

 actuating cylinder

22

 operation seat

23

 camp

24

 bearing sleeve

25

 driving part

26

 camp

27

 switching element

28

 Restoring member

30

 rotor

31

 second ball

32

 energy storage

33

 ramp

34

 Bullet

38

 outer ring

40

 guide ring

41

 approach

42

 recess

43

 first ball

44

 Rampenwälzeinrichtung

45

 ramp means

46

 inertial member

48

 control part

49

 Return spring

100

 diagram

101

 Curve

102

 boundary line

103

 curve area

104

 curve area

d

 axis of rotation

F _B

 operating force

M _OFF

 output torque

M _ONE

 drive torque

s

 actuating

QUOTES INCLUDE IN THE DESCRIPTION

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

Cited patent literature

• DE 102008013054 A1 [0003]
• DE 102004009832 A1 [0003]
• DE 102013207069 [0005]

Claims (9)

Coupling actuator ( 1 ) for actuating a friction clutch rotating around a rotation axis (d) ( 3 . 4 ) with an about the rotational axis (d) arranged electric servomotor ( 8th ) with a rotor (d) driven about the axis of rotation (d) 30 ), an actuator which converts a linear movement into an axial movement ( 9 ) for the axial displacement of a lever element ( 6 . 7 ) of the friction clutch ( 3 . 4 ) depending on a rotary drive of the servomotor ( 8th ) and between an actuator ( 9 ) and servomotor ( 8th ) depending on a load of the clutch actuator ( 1 ) automated switching two-stage planetary gear ( 10 ) with one with the rotor ( 30 ) rotationally coupled sun gear ( 13 ), by means of a freewheel ( 18 ) fixed to the housing ( 16 . 17 ), between sun gear ( 13 ) and ring gear ( 16 . 17 ) meshing, on a planet carrier ( 14 ) rotatably received planetary gears ( 15 ) and a sun wheel ( 13 ) and planet carrier ( 14 ) switchable connecting clutch ( 12 ), characterized in that the clutch ( 12 ) a load-dependent by axial displacement a connection between the sun gear ( 13 ) and planet carrier ( 14 ) separating switching element ( 27 ) and depending on an inertia in a stationary in a twisted state of the rotor ( 30 ) the connection restoring restoring member ( 28 ) having. Coupling actuator ( 1 ) according to claim 1, characterized in that the switching element ( 27 ) distributed over the circumference, in a first axial position a positive connection between the sun gear ( 13 ) and planet carrier ( 14 ) and in a second axial position releasing the positive engagement first balls ( 43 ), the first balls ( 43 ) axially displacing guide ring ( 40 ) and distributed over the circumference, axially biased, radially displaceable, a load-dependent axial displacement of the guide ring ( 40 ) controlling second balls ( 31 ) having. Coupling actuator ( 1 ) according to claim 2, characterized in that the return member ( 28 ) from a rotor ( 30 ) permanently assigned drive part ( 25 ) and a rotatable relative thereto and arranged on the guide ring ( 40 ) axially applied inertia part ( 46 ) with an axial between drive part ( 25 ) and inertia part ( 46 ) one in the direction of rotation of the rotor ( 30 ) an axial distance of this expanding ramp device ( 45 ) is provided. Coupling actuator ( 1 ) according to claim 3, characterized in that between inertial part ( 46 ) and drive part ( 25 ) in the circumferential direction against the widening effect of the ramp device ( 45 ) at least one return spring ( 49 ) is arranged. Coupling actuator ( 1 ) according to claim 3 or 4, characterized in that between the drive part ( 25 ) and one the second balls ( 31 ) tensioning control part ( 48 ) an axially effective energy store ( 32 ) is provided. Coupling actuator ( 1 ) according to one of claims 1 to 5, characterized in that in an opened state one of the actuator ( 9 ) compressed friction clutch ( 3 . 4 ) Sun gear ( 13 ) and planet carrier ( 14 ) with each other form-fitting by means of the clutch ( 12 ) are connected. Coupling actuator ( 1 ) according to claim 6, characterized in that at the beginning of torque transmission of the friction clutch ( 3 . 4 ) the clutch ( 12 ) Sun gear ( 13 ) and planet carrier ( 14 ) unlocks. Coupling actuator ( 1 ) according to claim 6 or 7, characterized in that at the opening of the friction clutch ( 3 . 4 ) fully displaced actuator ( 9 ) Planet carrier ( 14 ) and sun gear ( 13 ) remain unlocked. Coupling actuator ( 1 ) according to claim 8, characterized in that upon rotation of the rotor ( 30 ) with completely displaced actuator ( 9 ) an axial displacement of the guide ring ( 40 ) of the clutch ( 12 ) for connection of sun gear ( 13 ) and planet carrier ( 14 ) by means of a rotation of the inertia part ( 46 ) opposite the drive part ( 25 ) along the ramp device ( 45 ) is provided.

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