DE102016124269A1 - Piston-cylinder unit, in particular for a clutch actuation unit of a vehicle - Google Patents

Abstract

The invention relates to a piston-cylinder arrangement, in particular for a clutch actuator of a vehicle, consisting of a housing (1) formed, concentric cylinder in which a piston (5) is mounted axially movable, wherein the piston (5) on a Release bearing (7) engages, which actuates an actuator, wherein a outside of the housing (1) fixedly arranged sensor (10) in operative connection with a sensor connected to the movable piston (5) sensor target (9). In a piston-cylinder unit, the sensor target (9) is fastened directly to the piston (5), which spans a pretensioning spring (8) of the release bearing (7).

Description

The invention relates to a piston-cylinder unit, in particular for a clutch actuation unit of a vehicle, consisting of a housing formed as a concentric cylinder, in which a piston is mounted axially movable, wherein the piston engages a release bearing, which actuates an actuator, wherein a sensor externally fixed to the housing is in operative connection with a sensor target connected to the movable piston.

From the EP 1 898 111 A2 is a Zentralausrücker known for a hydraulic clutch actuation, which has a through-bore housing and a sleeve disposed therein, mounted thereon, on which an operatively connected to the clutch ring piston is guided, on which a release bearing inner ring is attached. Here, a sensor is mounted on the housing for detecting the axial position of the annular piston, which is associated with a displaceably guided magnetic body, which is connected axially free of play with an annular bearing body attached to the release bearing inner ring for driving through the annular piston. The connection of the magnetic body on the release bearing has the consequence that a tongue strike a arranged between the clutch and release bearing plate spring is transmitted from the release bearing on the magnetic body, resulting in that the signal received by the sensor is distorted. Since the release bearing but can also perform a predetermined independent movement without movement of the piston, the clutch is driven by the thereby distorted sensor signal, if it is not necessary, since this movement is considered by the sensor as a clutch release.

The invention has for its object to provide a piston-cylinder arrangement in which the tongue impact of the diaphragm spring has no effect on the movement of the sensor target.

According to the invention the object is achieved in that the sensor target is attached directly to the piston, which spans a biasing spring of the release bearing. By replacing the position of the piston and biasing spring, the sensor target can be attached directly to the piston. This positioning of the sensor target allows a movement of the sensor target only in response to the displacement of the piston. A connection to the release bearing no longer exists, so that no signals that are falsified as a result of the coupling-independent movement of the release bearing can be detected by the sensor. As a result, the quality of the output signal of the sensor is increased.

Advantageously, the sensor target is guided outside the housing by the piston. As a result, there is always a reliable and undisturbed operative connection with the sensor, whereby the noise behavior of the sensor is improved.

In one embodiment, the sensor target is guided between a bellows spanning the piston and the sensor fixedly attached to the housing.

In a variant, the biasing spring acting on the release bearing is arranged between a pressure chamber leading to the piston and a transmission input shaft. By exchanging the positions of piston and biasing spring no additional space is needed, which reduces the manufacturing cost.

In a further development, the sensor is arranged on an integrally formed from the housing support bracket. This design ensures a particularly firm support of the sensor, so that relative movements between the sensor and the sensor target are largely prevented.

The invention allows numerous embodiments. One of them will be explained in more detail with reference to the figures shown in the drawing.

• 1 ein Ausführungsbeispiel der erfindungsgemäßen Kolben-Zylinder-Anordnung

It shows:

• 1 An embodiment of the piston-cylinder assembly according to the invention

1 shows an embodiment of the piston-cylinder assembly according to the invention, in which a cylinder is a housing 1 forms. The housing 1 consists of an external pressure wall 2 and a guide sleeve 3 between which there is a pressure chamber 4 extends, in which axially movable a piston 5 is arranged. The piston 5 is with an inner ring 6 a release bearing 7 connected, which refers to a coupling, not shown, of a vehicle during the movement of the piston 5 acts. The release bearing 7 is from a preload spring 8th supported.

The external pressure wall 2 encloses the piston 5 in a release bearing 7 remote area of the piston 5 , On one of the outside pressure wall 2 uncovered fixed arm 11 of the piston 5 is a sensor target 9 For example, a magnet, fixed directly on the piston 5 Tethered, so the sensor target 9 the movements of the piston 5 reconstructs. The sensor target 9 opposite is a preferably magnetic sensor 10 firmly positioned. The release bearing 7 supporting preload spring 8th is outside of the annular piston 5 enclosed and includes itself a transmission input shaft 13 , To prevent contamination of the piston-cylinder assembly is a bellow 12 provided, which the piston 5 encloses the outside.

The sensor 10 detects the position of the sensor target 9 and gives as an output the position of the piston 5 to a not shown clutch control. This output signal is due to the fixed connection of the sensor target 9 to the piston 5 free from interfering signals.

LIST OF REFERENCE NUMBERS

1

casing

2

Außendruckwandung

3

guide sleeve

4

pressure chamber

5

piston

6

Inner ring of the release bearing

7

release bearing

8th

preload

9

sensor target

10

sensor

11

piston arm

12

bellow

13

Transmission input shaft

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

• EP 1898111 A2 [0002]

Claims (5)

Piston-cylinder arrangement, in particular for a clutch actuating device of a vehicle, consisting of a housing (1) formed concentric cylinder in which a piston (5) is mounted axially movable, wherein the piston (5) on a release bearing (7) which actuates an actuator, wherein a sensor (10) fixedly arranged on the outside of the housing (1) is in operative connection with a sensor target (9) connected to the movable piston (5), characterized in that the sensor target (9) is attached directly to the piston (5), which spans a biasing spring (8) of the release bearing (7). Piston-cylinder arrangement after Claim 1 , characterized in that the sensor target (9) outside the housing (1) through the piston (5) is guided. Piston-cylinder arrangement after Claim 1 or 2 , characterized in that the sensor target (9) is guided between a bellows (12) spanning the piston (5) and the sensor (10) fixedly attached to the housing (1). Piston-cylinder arrangement after Claim 1 or 2 characterized in that on the release bearing (7) acting biasing spring (8) between a piston (5) leading pressure chamber (4) and a transmission input shaft (13) is arranged. Piston-cylinder arrangement according to at least one of the preceding claims, characterized in that the sensor target (9) on a one-piece from the piston (5) formed piston arm (11) is fixed.

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