WO2014079432A1

WO2014079432A1 - Rotating slave cylinder fixed on a cover

Info

Publication number: WO2014079432A1
Application number: PCT/DE2013/200263
Authority: WO
Inventors: Philippe Wagner; Stefan Derlath
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2012-11-22
Filing date: 2013-10-30
Publication date: 2014-05-30
Also published as: DE112013005617A5; DE102013222019A1; DE112013005617B4

Abstract

The invention relates to a rotating slave cylinder (1), which is fixed on a cover, of a release device for the actuation of a clutch of a motor vehicle, with a stationary hydraulic feed/stator (2) of a hydraulic medium to a pressure chamber (3) of the rotating slave cylinder (rotor) (1) in which a release piston (4) operatively connected to the clutch is moveable axially along an axis of rotation (A) by pressurization of the hydraulic medium, wherein, according to the invention, at least one centrifugal mass (6) is integrated in the rotating slave cylinder, said centrifugal mass being operatively connected to the release piston and countering an undesired release movement of the release piston.

Description

Rotating lid-tight slave cylinder

The invention relates to a rotating cover-fixed slave cylinder according to the preamble of the first claim.

In the case of hydraulically actuatable disengagement devices, axial vibrations from the crankshaft, which are transmitted to the disengaging device, can lead to pressure fluctuations in the fluid system. To avoid this, concepts have been developed that provide for assembly / integration of the release device on the clutch cover (cover-resistant release). For example, the concentric slave cylinder and the clutch cover are combined to form a functional unit with internally closed power flow in the case of a cover-resistant release mechanism. The connection to the clutch cover is usually via a rolling bearing (cover bearing), which is provided in addition to a release bearing. As a result, the slave cylinder does not rotate with the clutch cover.

However, here too, the vibrations originating from the crankshaft can be transmitted to the clutch and thus to the clutch release bearing resting on a plate spring and thus also to the slave cylinder. In addition, the rolling bearings used represent a high cost factor and take up a considerable amount of space.

Therefore, other known solutions provide cover-resistant release devices, which dispense with the use of both a cover bearing and a release bearing. In these releasing devices, the concentric slave cylinder is fixed to the clutch cover of the clutch so as to rotate therewith. However, this means that in order to realize the supply of pressurized fluid from a stationary fluid supply device (also referred to as a stator) to the rotating slave cylinder (also referred to as a rotor), a rotary feedthrough has to be provided. Important here is a corresponding radial and axial bearing of the stator on the rotor with a functional design of storage locations to ensure safe operation of the seals and thus for the overall system, as well as the use of appropriate seals for rotary feedthrough.

Due to the stationary hydraulic supply, the hydraulic medium is conducted via the rotary feedthrough into the rotating disengager. If the pressure is sufficiently high, the release piston is displaced in the axial direction against the diaphragm spring tongues of the plate spring of the clutch. Since the pressure in the system is the same everywhere, this also affects the seals of the rotary feedthrough. By default, the release systems are designed with pressures up to 40 bar. These high pressures in conjunction with the high sliding speeds require structurally very complex seals, which has a negative effect on the cost and the required installation space.

An integrated in the hydraulic distance between the master cylinder and slave cylinder pressure ratio, by which the pressure of the master cylinder, for example, 40 bar is reduced to 5 bar, ensures that with a standstill hydraulic supply

Hydraulic fluid is passed through the rotary feedthrough in the rotating releaser at a reduced pressure, whereby low-cost seals for the rotary feedthrough can be used.

If the pressure is sufficiently high, the release piston in the axial direction against the

Disc spring tongues of the clutch moved. For a larger hydraulic effective area of the release piston is required. Since the slave cylinder rotates with it, the hydraulic medium is placed in a rotating motion and through the on the

Hydraulic fluid acting centrifugal force, the pressure increases with increasing diameter or radius as a function of the speed. There is thus the danger that the

Release piston disengages in the direction of the release bearing without actuating the clutch pedal.

The object of the invention is to develop a cover-fixed slave cylinder, with which an unintentional disengagement of the release piston is prevented even at high speeds.

This object is achieved with the characterizing features of the first claim.

Advantageous embodiments emerge from the subclaims.

The rotating deck-mounted slave cylinder of a release device for actuating a clutch of a motor vehicle, which includes a rotary feedthrough, has a stationary hydraulic supply / stator of a hydraulic medium to a pressure chamber of the rotating slave cylinder (rotor), in which a release piston operatively connected to the clutch along the Rotary axis (A) by pressurizing the

Hydraulic medium is axially movable, according to the invention in the rotating

Slave cylinder at least one operatively connected to the release piston

Fliehmasse is integrated, which counteracts an undesirable disengagement of the release piston. This is particularly intended for applications in which between master cylinder and slave cylinder, a pressure booster is arranged, which reduces the pressure of eg 40 bar on the master cylinder side to 5 bar on the slave cylinder side, which inevitably the hydraulically acting surface must be increased and thus an undesirable disengagement of the release piston with nichtbetätigtem clutch pedal must be prevented.

Advantageously, several flyweights are integrated into the slave cylinder, the knee lever with the release piston and an axially fixed portion of the rotor

Actively connected and act on the release piston against a disengagement with a speed-dependent drag.

Due to the centrifugal force of the flyweights, the toggle lever is stretched and thus generates an axial force against the release piston.

For this purpose, each flyweight via a connecting lever with the release piston

is operatively connected and is supported by a flyweight lever, at its pointing in the direction of the release piston end of the flyweight, at the axially fixed portion of the rotor from.

Advantageously, the connecting lever is pivotally mounted on the release piston and on

Float mass lever mounted and the flyweight lever is also pivotally coupled to the axially fixed portion of the rotor.

To attach the connecting lever on the release piston, a ring-like fastening element is clipped on the release piston via a bayonet lock. The

Fastener has first receptacles for the attachment of the Ausrückkolbenseitigen end of the connecting lever, wherein the number of first receptacles corresponds to the number of connecting lever. The attachment of the connecting lever on

Fastener is preferably realized by pins.

Rotor side, the flywheel lever of the toggle lever are pivotally mounted on a rotor mount, which has a number of connecting lever corresponding number of second receptacles for the flywheel lever. Again, the attachment via split pins

In the rotor holder cutouts are provided, through which engages the release piston, which acts against the plate spring of the clutch. To ensure a uniform contact pressure on the plate spring tongues despite the cutouts, is on the release piston a

Attached pressure plate, which act on the plate spring of the coupling in the axial direction. Advantageously, distributed over the circumference several flyweight between

Release piston and rotor mount arranged.

The flyweights are moved radially outward by a centrifugal force acting on them, and the connecting lever of the toggle lever thus counteracts the disengagement-side movement of the release piston.

If the clutch pedal is actuated when the engine is not started, the release piston retracts and the toggle bends further.

If the clutch pedal is not actuated and the engine is rotating, the fluid acts on the fluid

Centrifugal force. This results in a pressure increase with increasing diameter. The pressure acts on the surface of the release piston and results in an axial force that would unintentionally actuate the clutch. But also on the toggle acts a centrifugal force which has a stretching of the toggle lever result. By connecting the toggle lever with the release piston via the Ausrückkolbenbefestigung, a part of the centrifugal force of the toggle lever in the axial direction acts as a counter force to Ausrückkraft the release piston.

The invention will be described below with reference to embodiments and associated

Drawings explained in more detail.

Show it:

1 shows a longitudinal section through a rotating lid-tight slave cylinder, Figure 2 is an exploded view of the release piston and the fastener. Figure 3 shows the detail X acc. Figure 2, Figure 4 shows the detail of Z gem. FIG. 2,

FIG. 5 shows the basic representation of the rotor holder, which is connected to the housing (rotor).

is connected

Figure 6 shows the schematic diagram of the pressure plate which is attached to the release piston.

The rotating topmost slave cylinder 1 (rotor) of a release device for the

Actuation of a clutch, not shown, of a motor vehicle has, according to FIG. 1, a stationary hydraulic supply (stator) 2 of a hydraulic medium to a pressure chamber 3 of the rotating slave cylinder (rotor) 1, in which a release piston 4 runs along the Rotary axis A is axially movable by pressurization of the hydraulic medium.

Each flyweight 6 is operatively connected via a connecting lever 7 with the release piston 4 by means of an annular fastening element 4.1 and is supported by a

Fliehmassenhebel 8 on a disc-like rotor mount 9, which is connected to the rotor 1 from. The connecting lever 7 is pivotally mounted on the release piston and on

Fliehmassenhebel 8 mounted and the flyweight lever 8 is pivotally mounted on the rotor mount 9. The pivotal attachment is in each case via split pins 10. The connecting lever 4 and the flyweight lever 8 are inclined relative to one another such that their ends connected to one another in the region of the flyweight 6 are connected radially inside the ends of the toggle lever which are fastened to the fastening element 4.1 and to the rotor attachment. lie.

Due to the centrifugal force during the rotation of the release piston 4 and the toggle lever 5, the flyweights 6 are moved radially outward and the toggle lever 5 is stretched. The toggle lever 5 thus generates an axial force against the release piston 4 and thereby prevents unwanted disengagement of the release piston.

The here four toggle 5 are evenly distributed on the circumference. A toggle lever 5 consists respectively of the connecting lever 7 and a flyweight lever 8 having at one end a higher mass (flyweight 8).

The fastening element 4.1 is pushed onto the release piston 4 according to FIG. It has excerpts 4.2. and the release piston 4 to corresponding paragraphs 4.3 (see also Figures 3 and 4), which engage in one another after assembly and serve for positioning and as anti-rotation.

The fastening element 4.1 has a number of connecting levers 7 corresponding number of first receptacles 11 for the attachment of the Ausrückkolbenseitigen end of the connecting lever 7, which is not shown in Fig. 2.

Axially the fastening element 4.1 is secured by a bayonet lock 12 (see FIG. 1) which also secures the rod seal 13 of the release piston 4.

The piston 4 has projections 14 distributed over the circumference, as can be seen from FIG.

After the fastener 4.1 is attached to the piston 4, the toggle lever 5 with the discharge piston-side end of the connecting rod 7 in the first Receivers 11 of the fastener 4.1 by means of cotter pins 10 pivotally mounted.

The flyweight levers 8 are now pivotally mounted to the rotor attachment 9 on the rotor side. For this purpose, the rotor attachment 9 has a number of second receptacles 9.1 corresponding to the number of flyweight levers 8. Here four four shots 9.1 are provided due to the four toggle lever 5.

The rotor mounting 9 has cutouts 9.2, through which the release piston 4 extends with its projections 14 in the assembled state.

After the flyweight levers 8 are connected to the rotor mount 9 at their second receptacles 9.1 by means of split pins 10 (see Fig. 6), a pressure plate 15 is fastened to the projections 14 of the piston 4 reaching through the cutouts 9.2 by clipping on a not shown Diaphragm spring of the coupling acts in the axial direction.

From Figure 1 it is also seen that between the slave cylinder 1 and the

Hydraulic supply 2, a rotary feedthrough 16 is provided for the hydraulic medium. By the stationary hydraulic supply 2 and the rotary feedthrough 16, the hydraulic medium is passed into the rotating slave cylinder.

After a certain time, the complete hydraulic medium rotates. By acting on the hydraulic medium centrifugal force, the pressure increases exponentially with the

Diameter. This pressure acts on the surface of the release piston 4 and has an axial force result, which moves the release piston 4 to disengage, whereas the toggle lever acts.

Pressing now the clutch pedal, not shown, the balance of power is released in favor of the disengagement and it also acts in the release force in the axial direction. As a result, the release piston 4 shifts in the axial direction against the plate spring, not shown, of the clutch and at the same time presses the toggle lever 5, whereby the flyweights 6 move radially inwardly. LIST OF REFERENCE NUMBERS

1 slave cylinder

stationary hydraulic supply

3 pressure chamber

4 release pistons

4.1 fastening element

4.2 cutouts

4.3 paragraphs

5 toggle lever

6 flyweight

7 connecting lever

8 flywheel lever

9 rotor attachment

a. second shots

b. cutouts

10 pins

1 1 first shots

12 bayonet lock

13 rod seal

14 projections

15 printing plate

16 rotary feedthrough

A rotation axis

Claims

Patent claims

Rotating cover-fixed slave cylinder (1) of a release device for the

Actuation of a clutch of a motor vehicle with a stationary one

Hydraulic feed/stator

(2) a hydraulic medium to a pressure chamber

(3) of the rotating slave cylinder (rotor) (1), in which one with the clutch in

Actively connected release piston (4) can be moved axially along an axis of rotation (A) by pressurizing the hydraulic medium, thereby

characterized in that at least one centrifugal mass (6), which is in operative connection with the release piston (4), is integrated into the rotating slave cylinder (1), which prevents an undesirable release movement of the release piston

(4) counteracts.

Slave cylinder according to claim 1, characterized in that several

Flying masses (6) are integrated into the slave cylinder via toggle levers

(5) with the release piston (4) and an axially fixed area of the rotor (1)

There is an active connection and on the release piston (4) against one

Disengagement movement acts with a speed-dependent counterforce.

Slave cylinder according to claim 1 or 2, characterized in that each

The centrifugal mass (6) is operatively connected to the release piston (4) via a connecting lever (7) and is located on an axially fixed one via a centrifugal mass lever (8), at the end of which the centrifugal mass (6) points in the direction of the release piston (4). Area of the rotor (1) is supported.

Slave cylinder according to one of claims 1 to 3, characterized in that the connecting lever (7) is pivotally mounted on the release piston (4) and on the centrifugal mass lever (8) and that the centrifugal mass lever (8) is pivotable on the axially fixed area of the rotor (1). is attached.

Slave cylinder according to claim one of claims 1 to 4, characterized

characterized in that a ring-like fastening element (4.1) is attached to the release piston (4) via a bayonet lock (12) and that a number of first ones corresponding to the number of connecting levers (7) is attached to the fastening element (4.1). Recordings (11) are arranged for fastening one end of the connecting lever (7).

6. Slave cylinder according to one of claims 1 to 6, characterized in that the centrifugal mass levers (8) are pivotally attached to a rotor fastening (9) on the rotor side, and that the rotor fastening (9) is one of the number of toggle levers (5).

corresponding number of second receptacles (9.1) for attaching the

Has a centrifugal mass lever (8).

7. Slave cylinder according to one of claims 1 to 6, characterized in that the rotor fastening (9) has cutouts (9.2) through which the release piston (4) extends.

8. Slave cylinder according to one of claims 1 to 7, characterized in that a pressure plate (15) is attached to the release piston (4), which acts on a disc spring of the clutch in the axial direction.

9. Slave cylinder according to one of claims 1 to 8, characterized in that a plurality of toggle levers (5) with centrifugal masses (6) are arranged between the release piston (4) and the rotor holder (9) distributed over the circumference.

10. Slave cylinder according to one of claims 1 to 9, characterized in that the centrifugal masses (6) are moved radially outwards by a centrifugal force acting on them and the toggle lever (5) is moved by increasing its length

counteracts the movement of the release piston (4) on the release side.