DE102011018411A1 - Hydraulic actuated release unit i.e. concentric slave cylinder, for operating e.g. dry friction clutch in gear box of motor car to achieve over or reduction ratios, has friction increasing device increasing friction between spring and ring - Google Patents

Abstract

The unit (1) has a friction increasing device in contact with a preload spring (10) on an abutment surface for increasing friction between the preload spring and a preload spring attachment ring (11). The friction increasing device is designed as a ramp that exhibits inclination that is aligned against another inclination that occurs in the preload spring. A surface area of the ramp faces the preload spring, and is molded in a linear or concave curved manner. The ramp is aligned transverse to a circumferential direction of the attachment ring.

Description

The invention relates to a releaser for clutch actuation with a contact surface for a preload spring.

Vorlastfederanlageringe are known from the prior art, which come in releasers of motor vehicle coupling units used.

In motor vehicles clutch units are used so that different gears can be inserted to achieve different over- or reduction ratios in a transmission. In this case, a torque is transmitted from a drive shaft, which is driven by the internal combustion engine, to a transmission input shaft. The torque and the speeds are then converted in the transmission, so that there are different torques and speeds on the transmission output side or on the existing there shaft.

For the hydraulic actuation of the clutch is known to be a slave cylinder, which may also be arranged concentrically around the transmission input shaft and is referred to in this case as a release or Concentric slave cylinder (CSC). This release consists essentially of a housing by a pressure chamber sealingly, a piston is guided axially movable. In addition, this releaser has a release bearing, which is known to consist of an outer ring, an inner ring and arranged therebetween rolling elements. The inner ring connected to the piston transmits the applied disengagement force to a lever connected to the clutch, so that the clutch can be opened or closed via this.

During operation of the vehicle, the outer ring of the release bearing is in rotation, which is not passed through the rolling elements to the inner ring, so that this is dreenktkoppelt from the outer ring.

The piston connected to the inner ring of the release bearing is constantly biased by a preload spring. This preload spring is supported on the one hand on the housing of the releaser and on the other hand on a movable to the inner ring on this adjacent Vorlastfederring.

This mode of operation of the preload spring is both from the DE 44 03 307 B4 as well as the DE 103 49 171 A1 seen. The difference between the two solutions is that in the case of DE 103 49 171 A1 a firm connection was made between the preload spring ring and the preload spring.

During operation of a vehicle, there are conditions that cause the existing between the inner ring and the outer ring of the release bearing lubricant, such as a grease, stagnates and causes that yet a rotational movement is transmitted from the outer ring to the inner ring. These conditions occur especially at very low temperatures, for example below -15 ° C, especially below -25 ° C.

In the solution according to the DE 19620571 A1 An attempt is made to realize a better areal force transmission of the preload spring on the Vorlastfederanlagering and the housing. For this purpose, the largest possible area of the helical preload spring is held in contact with the preload spring contact ring and the housing.

However, the known solutions cause under the conditions mentioned that the rotational movement of the outer bearing ring is passed to the inner bearing ring due to the stagnant grease, and passed on the staggered Vorlastfederanlagering with the preload spring, as between the Vorlastfederanlagering and the preload spring so far Established. As a result, breakage of the preload spring can occur under said conditions, which leads to failure of the release mechanism and thus failure of the clutch assembly. This case should be avoided by the invention.

It is therefore an object of the present invention to provide a fail-safe release for clutch operation while maintaining the previous space requirements.

This object is achieved with a releaser characterized in that on the contact surface of Vorlastfederanlageringes at least one engageable with the preload spring Reiberhöhungsvorrichtung to increase the friction between the preload spring and Vorlastfederanlagering is present.

Such a friction increasing device can be realized by a variety of configurations. For example, by a friction-increasing roughening of the contact surface, which increases in the circumferential direction, a correspondingly shaped element may be provided by which the preload spring is forcibly guided to another plane. In this way, the preload spring can rotate in extreme situations when the frictional forces are exceeded, whereby a breakage of the preload spring is prevented and thus a total failure is avoided. However, in the normal state, the spring is rotationally fixed on the preload spring abutment ring.

Advantageous embodiments are claimed in the subclaims and explained in more detail below.

Thus, it is advantageous if the Reiberhöhungsvorrichtung is designed as a ramp having a first slope, which is aligned against a present in the formed as a helical spring preload spring second pitch. If, in an extreme situation, torque is transmitted to the preload spring via the preload spring contact ring, one end of the preload spring may slide over the ramp as force increases and effectively prevent breakage of the preload spring.

If the preload spring facing surface of the ramp is formed straight or concave, the arrangement can be adjusted as needed by means of the forces to be overcome as needed.

In order to achieve a Selbstzentrierungseffekt the preload spring, it is advantageous if the ramp is aligned transversely to a circumferential direction of Vorlastfederanlagerings. In this case, angles between 10 ° and 60 °, in particular 45 ° offer.

If several Reiberhöhungsvorrichtungen evenly distributed on the contact surface in the circumferential direction, about 2, 3, 4, 5 or 6, it is possible in extreme situations that the preload spring slips over the ramps several times until the extreme situation is no longer present; So z. B. that grease has heated sufficiently, so that no torque is transmitted from the outer bearing ring on the inner bearing ring. The preload spring then returns faster to a rotation-free state.

It is also advantageous if there is no radially aligned and orthogonal standing on the contact surface stop on the contact surface. A blocking element which is present somewhere on the preload spring contact ring and which, even in an extreme situation, forces a blockage of the preload spring in the direction of rotation, is thereby avoided.

The invention will be explained in more detail below with reference to an embodiment with accompanying drawings.

Show it:

1 a release according to the invention in a perspective cross-sectional view;

2 an interior view of Vorlastfederanlageringes, according to 1 ;

3 an outside view of Vorlastfederanlageringes 2 .

4 a floor plan of Vorlastfederanlageringes 2 .

5 a cross-sectional cutout along the line VV through the Vorlastfederanlagering 4 and

6 a cross-sectional detail along the line VI-VI through the Vorlastfederanlagering 4 ,

The figures are merely schematic in nature and are for the sole purpose of understanding the invention. The same reference numerals are used for the same elements.

In 1 is a hydraulically actuated release button 1 shown. The releaser has a housing 2 on, that is a pressure chamber 3 together with a guide cylinder 4 formed. Via a feed opening 5 A hydraulic fluid, such as oil, enters the pressure chamber 3 initiated, so that a ring cylinder seal combination 6 in the direction of a release bearing 7 is displaceable. During the displacement, both a seal 8th , as well as a ring cylinder 9 emotional. In addition to the force applied by the hydraulic power, also brings a preload spring 10 Force on the release bearing 7 on. The preload spring 10 supports itself with one end on the housing 2 from. The other end of the preload spring 10 rests on a preload spring contact ring 11 from.

The force of the spirally formed preload spring 10 is via the Vorlastfederanlagering 11 in the release bearing 7 forwarded. Here is the traction of an inner bearing ring 12 the release bearing 7 via a rolling bearing 13 the release bearing 7 on an outer bearing ring 14 determine.

The preload spring 10 is in the invention not by positive locking elements on a rotation on a contact surface of Vorlastfederanlagerings 11 prevented. The contact surface 15 is on the inner bearing ring 12 opposite side of Vorlastfederanlagerings 11 educated. This is especially good in 2 to recognize.

In 2 Among other things, it is also a circulating board 16 on the side of the contact surface 15 of preload spring mounting ring 11 to recognize. Substantially extending in the circumferential direction, although offset by 20 °, is a friction increasing device 17 intended. The rice raising device 17 is designed as a ramp that has a straight surface 18 which, however, inclined to the rest of the contact surface 15 is designed. The inclination is between 20 and 60 °, in the present case 45 °.

One end of the preload spring 10 gets into contact with the trained as ramp Reiberhöhungsvorrichtung 17 , wherein advantageously several Reiberhöhungsvorrichtungen 17 can be arranged evenly offset over the circumference.

The more the preload spring 10 over the surface 18 The ramp slides, the more it is compressed and the higher the friction between the surface 18 and thus the contact surface 15 , and the preload spring 10 ,

In the 3 to 6 is the Vorlastfederanlagering 11 presented from different perspectives and in different cross-sectional views. Thus, in the synopsis of the figures, the sector-like intrusion of the friction-raising device 17 into the interior, so from the contact surface 15 away toward a circumferential distal end of the shelf 16 to recognize.

This release with a Reiberhöhungsvorrichtung between Vorlastfederanlagering and preload spring is used to operate a simple as well as for the operation of a dual clutch, preferably dry friction clutches are used.

LIST OF REFERENCE NUMBERS

1

releaser

2

casing

3

pressure chamber

4

guide cylinder

5

feed

6

combination

7

release bearing

8th

poetry

9

ring cylinder

10

preload

11

Vorlastfederanlagering

12

Inner bearing ring

13

roller bearing

14

Outer bearing ring

15

contact surface

16

shelf

17

Reiberhöhungsvorrichtung

18

surface

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 4403307 B4 [0007]
• DE 10349171 A1 [0007, 0007]
• DE 19620571 A1 [0009]

Claims (6)

Releaser ( 1 ) for actuating a clutch of a motor vehicle with a Vorlastfederanlagering ( 11 ), which has a contact surface ( 15 ) for a preload spring ( 10 ), characterized in that on the contact surface ( 15 ) at least one with the preload spring ( 10 ) engageable friction increasing device ( 17 ) to increase the friction between the preload spring ( 10 ) and the Vorlastfederanlagering ( 11 ) is available. Releaser ( 1 ) according to claim 1, characterized in that the friction increasing device ( 17 ) is formed as a ramp which has a first pitch, which is opposite to that in the preload spring ( 10 ) existing second pitch is aligned. Releaser ( 1 ) according to claim 2, characterized in that the preload spring ( 10 ) facing surface ( 18 ) of the ramp is formed straight or concave. Releaser ( 1 ) according to one of claims 2 or 3, characterized in that the ramp ( 17 ) transversely to a circumferential direction of Vorlastfederanlagerings ( 11 ) is aligned. Releaser ( 1 ) according to one of claims 1 to 4, characterized in that a plurality of friction increase devices ( 17 ) on the contact surface ( 15 ) of the preload spring contact ring ( 11 ) are distributed uniformly spaced in the circumferential direction. Releaser ( 1 ) according to one of claims 1 to 5, characterized in that on the contact surface ( 15 ) of the preload spring contact ring ( 11 ) no radially aligned and orthogonal on the contact surface ( 15 ) standing stop exists.

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