CN111207162A

CN111207162A - Method for adjusting the preload of a clutch actuating system with an automatic release system

Info

Publication number: CN111207162A
Application number: CN201911132076.9A
Authority: CN
Inventors: 迈克尔·施耐德
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2018-11-22
Filing date: 2019-11-19
Publication date: 2020-05-29
Anticipated expiration: 2039-11-19
Also published as: DE102018129380A1; CN111207162B

Abstract

The invention relates to a method for adjusting the preload of a clutch actuating system having an automatic release system, in which method an actuator unit (4) driven by an electric motor (6) acts by means of a displacement element (8) on a release bearing (11) which can act on an adjusting element (10) provided with a preload, which acts with a pressing force on a clutch (9), wherein the release bearing (11) is mechanically coupled to the adjusting element (10) by the actuator unit (4) when a preload point provided in the actuator path is reached. In the preload adjustment method, the preload of the adjustment element (10) is reduced when the motor torque of the electric motor (6) is increased, thereby increasing the pressing force acting on the clutch (9) which is present at the preload point.

Description

Method for adjusting the preload of a clutch actuating system with an automatic release system

Technical Field

The invention relates to a method for adjusting the preload of a clutch actuating system having an automatic release system, in which method an actuator unit driven by an electric motor acts on a release bearing by means of a displacement element, which can act on an adjusting element provided with a preload, which acts on the clutch with a pressing force, wherein the release bearing is mechanically coupled to the adjusting element by means of the actuator unit when a preload point set in the actuator stroke is reached.

Background

DE 102016123952 a1 discloses a method for operating a clutch of a hybrid drive train, in which method the hybrid drive train can be operated by means of an operating device, wherein the operating device has an electric actuator unit which acts adjustably by means of a displacement element on an operating bearing, which in turn is coupled or can be coupled in a movable manner to an adjusting element of the clutch. Here, the preload point at which the operating bearing presses with minimal thrust on the adjusting element is determined in such a way that: firstly, the moving element is moved apart by adjusting an actual characteristic curve, which describes the characteristic of the physical movement characteristic value of the moving element with respect to the movement displacement at which the preload theoretically lies; the actual characteristic curve is then compared with the theoretical characteristic curve stored for the shift displacement, and a preload point is determined at each point along the actual characteristic curve with no or minimal deviation from the comparison point of the theoretical characteristic curve.

The clutch actuation system, which is in particular designed as an electric clutch system with an automatic release system, has a very high preload, as a result of which the release bearing has a mechanical contact with the adjusting element. In this case, a significantly greater pressing force must be provided in the clutch design than, for example, in the case of a normal manual shift, in which the pedal is connected to the clutch actuator not electrically, but hydraulically or pneumatically. During the clutch transmission, about 1000N is lost due to the preload. It is difficult to additionally prestore a pressing force of 1000N for an adjusting element designed in the form of a cup spring, and in conventional clutches additionally prestoring a pressing force of 1000N without wear results in unnecessarily high operating forces in the worn state, which limits the field of application, since the release system is also limited by its maximum force.

Disclosure of Invention

The object of the invention is to provide a preload adjustment method for a clutch actuating system having an automatic release system, in which the pre-stored pressing force for the clutch to come into contact with the release system is increased without increasing the size of the clutch.

According to the invention, the technical problem is solved as follows: in the case of an increase in the motor torque of the electric motor, the preload of the actuating element is reduced, as a result of which the pressing force acting on the clutch, which is present at the preload point, is increased. This has the advantage that, when the preload acting counter to the pressing force of the clutch is reduced, a temporary pressing force surplus occurs, which can be used for torque transmission of the clutch.

Advantageously, the preload is reduced in the event of a maximum motor torque of the electric motor being called for. In this case, the pressing-force surplus acts as a stationary reservoir, since the smaller preload needs to be overcome and the pressing force is reduced by a small amount only.

In one variant, the preload is reduced at a first preload point, which is located before a second preload point in the operating displacement of the actuator unit, at which the preload independent of the motor torque of the electric motor is applied. Based on the different preload points that need to be adjusted by the actuator unit, the clutch can be actuated with the application of a preload according to the standard that can eliminate all tolerances, but also with a reduced preload. The use of a reduced first preload makes it possible to reduce the wear of the adjusting element, which wear occurs during the adjustment of the second preload by the actuator unit moving towards the second preload point.

In one embodiment, the first preload occurring at the first preload point is significantly smaller than the second preload occurring at the second preload point. The smaller the first preload occurring at the first preload point, the higher the portion of the pressing force that can be used as a static accumulator for actuating the clutch.

In one embodiment, the first preload is between 70 and 100N and the second preload is between 300 and 400N. In this case, all available pressing forces can be applied to the clutch to transmit the clutch torque.

In one variant, at the first preload point, the preload is reduced to 0N. The adjusting element and the release bearing can thus be mechanically coupled when the maximum motor torque is called up, even in the absence of a pressing force.

Advantageously, the pressing force is set to 0N by mechanically decoupling the release bearing from the adjusting element of the clutch.

In a further embodiment, the decoupling system, which is mechanically decoupled from the actuating element, is moved slowly to the actuating element of the clutch when the first preload point is known. The contact of the release bearing on the actuating element compensates for tolerances of the clutch actuating system, so that the preload point can be adjusted particularly precisely.

Drawings

The invention has a variety of embodiments. One of which is explained in detail in accordance with the illustration shown in the drawing. The attached drawings are as follows:

FIG. 1 illustrates one embodiment of a clutch operating system having an automatic disconnect system.

Detailed Description

Fig. 1 shows a clutch actuation system with an automatic release system for electrically operating a clutch in a vehicle. Such systems are also referred to as electric clutch systems. Such a clutch enables the driver of the vehicle to simply operate the manual transmission.

In this case, the clutch operating system 1 has a clutch pedal 2, the clutch pedal 2 is connected to an actuator unit 4 via a master cylinder 3, and a control unit 5 is flange-mounted on the actuator unit 4. The actuator unit 4 has a spindle 7 driven by an electric motor 6, the spindle 7 actuating a piston 8 mounted axially movably in a pressure chamber 12, which moves a clutch 9. Via the pressure chamber 12, the clutch 9 can be actuated by the clutch pedal 2 or the clutch 9 can be actuated automatically by the actuator unit 4 which is actuated by the control unit 5.

The clutch 9 has a disk spring 10 as an adjusting element, which disk spring 10 is actuated by means of a release bearing 11 of the actuator unit 4 driven axially by the electric motor 6. The piston 8 of the actuator unit 4, which is mounted in the pressure chamber 12, is displaced against the release bearing 11, the disk spring 10 bearing against the release bearing 11. At the preload point, which represents the position in the stroke traversed by the actuator unit 4, the release bearing 11 presses with minimal thrust against the cup spring 10. The preload point is selected such that unintentional rotation of the cup spring 10 relative to the release bearing 11 is prevented, taking into account all occurring tolerances. Thereby preloading the belleville spring 10. But the preload reduces the pressing force acting on the clutch 9.

In the method implemented with the clutch actuation system 1, two preload points in the stroke of the actuator unit 4 are set in the control unit 5. In the event of a maximum motor torque of the electric motor 6 being called up, the clutch pedal 2 is moved by the driver to a first preload point, which is located before the second preload point in the direction of movement of the actuator unit 4 for engaging the clutch. At the first preload point, the preload applied to the cup spring 19 is reduced by loosening the contact area between the cup spring 10 and the release bearing 11. Thereby, the pressure applied by the actuator unit 4 to the clutch 9 is only reduced by the reduced preload, and thus an increase in the pressing force on the clutch 9 is achieved. At the second preload point, which is present according to the standard in all motor vehicles having a clutch actuation system, a preload of typically approximately 300 to 400N is applied to the cup spring 10, taking into account and maintaining the reliability and tolerances. In the ideal case, the preload can be adjusted to 0N when the release bearing 11 of the clutch actuator 4 has completely displaced the disk spring tongue of the disk spring 10. Here, 100% of the pressing force can be used to transmit the clutch torque, since there is no preload on the cup spring 10.

In order to ascertain the first preload at the first preload point, the clutch actuation system 1 is reliably ascertained by the release bearing 11 being completely removed from the spring tongue tip of the disk spring 10 and subsequently touching the spring tongue tip of the disk spring 10 in order to compensate for tolerances.

With this solution, the preload of the cup spring 10 can be reduced in the existing clutch actuation system and at the same time the pressing force at the clutch 9 can be increased.

List of reference numerals

1 Clutch actuation System

2 Clutch pedal

3 driving cylinder

4 actuator unit

5 control unit

6 electric motor

7 screw rod

8 piston

9 Clutch

10 disc spring

11 Release bearing

12 pressure chamber

Claims

1. Method for adjusting the preload of a clutch operating system with an automatic disengagement system, in which method, an actuator unit (4) driven by an electric motor (6) acts on the release bearing (11) by means of a displacement element (8), the release bearing can act on an adjusting element (10) provided with a preload, the adjusting element acts on the clutch (9) with a pressing force, wherein the release bearing (11) is mechanically coupled with the adjusting element (10) by the actuator unit (4) when a preload point provided in the actuator stroke is reached, characterized in that the preload of the adjusting element (10) is reduced when the motor torque of the electric motor (6) is increased, the pressing force acting on the clutch (9) existing at the preload point is thereby increased.

2. The method of claim 1, wherein the preload is reduced in the event of invoking a maximum motor torque of the motor.

3. Method according to claim 1 or 2, characterized in that the preload on a first preload point, which is located before a second preload point in the operating path of the actuator unit (4), is reduced, on which second preload point a preload is applied which is independent of the motor torque of the electric motor (6).

4. Method according to claim 3, characterized in that the first preload of the adjusting element (10) occurring at the first preload point is significantly smaller than the second preload occurring at the second preload point.

5. The method of claim 4, wherein the first preload is between 70 and 100N and the second preload is between 300 and 400N.

6. Method according to at least one of the preceding claims, characterized in that at the first preload point the preload is reduced to 0N.

7. Method according to claim 6, characterized in that the preload is adjusted to 0N by mechanically decoupling the release bearing (11) from an adjusting element (10) of the clutch (9).

8. Method according to at least one of the preceding claims, characterized in that during learning of the first preload point, a decoupling system (11) mechanically decoupled from the adjusting element (10) is slowly moved to the adjusting element (10) of the clutch (9).