DE102008052446B4 - Clutch slave cylinder - Google Patents

Abstract

Clutch slave cylinder (1) in the form of a arranged around a transmission input shaft Zentralausrückers with a housing (3) with a pressure chamber open on one side (10), in which an axially displaceable annular piston (9) is received and the radially inwardly disposed through a transmission input shaft guide sleeve ( 4) and radially outwardly by a ring-cylindrical wall part (8) is formed, wherein the wall part (8) is received as a separate component in the housing (3), characterized in that the wall part (8) at its in a receptacle (13) facing an end face an annular disc-like projection (17) into the pressure chamber (10) which is axially sealed against a rear wall of the housing (3) and the annular disc-like projection (17) on the guide sleeve (4) is supported.

Description

The invention relates to a slave cylinder in the form of a central release for a friction clutch.

Zentralausrücker for clutch systems are for example from the DE 10039242 A1 with one-piece housing made of plastic or aluminum or two-piece housing made of plastic or aluminum with an attached metal guide sleeve known. The plastic housings can be manufactured by means of an injection molding process, the housings made of aluminum by means of a die casting process. The production of housings of Zentralausrückern is complicated due to the existing undercuts. Thus, if necessary, the housings must be machined and / or complicated injection molds produced. Furthermore, the inspection of the sealing surfaces of the housing to the annular piston is difficult due to difficult access. When using steel guide sleeves which are connected to a housing, sealing problems can occur.

Furthermore, from the publications JP H04-307124A . DE 199 51 414 A1 and DE 197 16 473 A1 Zentralausrücker according to the preamble of claim 1 known.

Starting from this prior art, the task is to propose a clutch slave cylinder whose production is simple and inexpensive.

The object is achieved by a clutch slave cylinder having a housing with a pressure chamber open on one side, in which an axially displaceable annular piston is received and which is formed radially inwardly by a guide sleeve disposed about a transmission input shaft and radially outwardly by a ring-cylindrical wall part, wherein the wall part as a separate Component is accommodated in the housing. In this way, two simple parts, namely housing and wall part can be produced separately, which can be made in a benefit, so that optionally an injection molding or die-casting tool can produce both parts and the logistical effort can be neglected. Furthermore, the two sealing surfaces of the pressure chamber are easily accessible and can therefore - without additional tools - if necessary - processed, for example, polished and / or greased. Due to the good visibility of the sealing surfaces they can be inspected prior to assembly of the slave cylinder, so that damage to the sealing surfaces, such as voids formation, are detected before the costly assembly and not at the final acceptance of the finished slave cylinder. The parts can be made of aluminum, for example by means of a die casting process or of plastic, for example by means of an injection molding process. In particularly configured embodiments, different materials can be used for the two components, so that for example aluminum for the housing and plastic for the wall part or two different plastics can be used, the two plastics can be adapted to the different requirements. Thus, the statically demanding housing, for example, from plastic, for example, reinforced by means of fibers or balls made of plastic or graphite plastic and less demanding wall part without additional reinforcement made of plastic.

Furthermore, the wall part at its end facing in a receiving end an annular disk-like extension into the pressure chamber, which is sealed axially against a rear wall of the housing. In this way, results in pressure buildup in the pressure chamber, an axial support force on the extension, which ensures the fixation of the Wandungsteils in the receptacle of the housing by the annular piston is supported at pressure buildup in the pressure chamber at the extension and thus self-reinforcing the extension to a housing wall of the housing braced. In addition, an axial seal between the housing and extension is provided in this area. In this way, the clutch slave cylinder itself can be operated for testing purposes without axial tension. For further stabilization of the wall part in the receptacle of the housing, the radial extension is supported on the guide sleeve.

In order to connect the two parts positioned in relation to one another, the wall part can have an axial projection which is inserted into a receptacle of the housing which fits precisely thereto. Such a recording can advantageously be achieved without additional axial securing, since the clutch slave cylinder attached to the housing on the gear housing and the annular piston is clamped against the plate spring tongues or other parts of a lever system for actuating the clutch. Advantageously, the axial projection is sealed relative to the receptacle, it being possible for a radial penetration for a pressure connection opening into the pressure chamber to be provided on the axial projection and the axial projection is sealed on both sides of the puncture axially spaced over the circumference to the recess of the housing. In this way, the supply of the pressure medium via the axial projection into the pressure chamber can take place, wherein the axial projection for better distribution of the pressure medium of the pressure port with a narrow diameter by means of a wall part provided to the pressure port provided annular groove, from which the puncture is guided in the pressure chamber.

• 1 einen Längsschnitt durch ein Ausführungsbeispiel eines Kupplungsnehmerzylinders und
• 2 einen Querschnitt durch den in 1 gezeigten Kupplungsnehmerzylinder.

The invention will be explained in more detail with reference to Figures 1 and 2. Showing:

• 1 a longitudinal section through an embodiment of a clutch slave cylinder and
• 2 a cross section through the in 1 shown clutch slave cylinder.

The clutch slave cylinder 1 is an unillustrated, about a rotation axis 2 arranged rotating transmission input shaft. The housing 3 , which may be made of plastic or aluminum, has radially inside a guide sleeve 4 on, the cylindrical outer surface as a sealing surface 5 for the U-ring seal 6 is trained. The outer sealing surface 7 for the U-ring seal 6 is through the inner surface of the Wandungssteils 8th educated. The U-ring seal 6 is, for example, axial and radial play with a seal carrier or directly to the annular piston 9 Tied, leaving one of the ring piston 9 as well as the housing 3 and the wall part 8th a pressure chamber 10 formed with the pressure port 11 is communicated and connected via this with a pressure supply device, such as a master cylinder or a switchable via a pressure control valve pump, which is controlled automatically or by a driver, for example by means of a clutch pedal. Depending on the pressure connection 11 applied pressure, the pressure chamber becomes 10 extended by the ring piston 9 is displaced axially and one with the annular piston 9 by means of a receiving device connected release bearing 12 acted on, the associated friction clutch, which may be an on or pushed clutch actuated.

In the case 3 is an annular recess 13 provided, in which the wall part 8 by means of a correspondingly adapted axial approach 14 can be fitted. In the area of its radial outer surface, the axial projection 14 an annular groove 15 on, on both sides by means of seals 16 radially opposite the housing 3 and thus sealed to the outside. The ring groove 15 stands in connection with the not visible pressure supply of the pressure connection. Furthermore, the annular groove 15 with one or more channels 19 with the pressure chamber 10 connected, so that regardless of the positioning of the wall part 8 relative to the housing 3 over the ring groove 15 and the channels 19 a secure connection of the pressure connection 11 can be done to the pressure chamber and during assembly not on an exact positioning of wall part 8th and housing 3 must be respected.

The wall part 8th has a radial approach 17 on, located on the outer circumference of the guide sleeve 4 supported and axially relative to the housing by means of seal 18 is sealed. The radial approach forms 17 a wall of the pressure chamber at which the annular piston 9 supported by the formation of a pressure, so that the wall part 8th in the case 3 is supported. A complex connection of the two parts against each other is therefore not required axially. Nevertheless, both parts against each other by means of a simple backup, for example, caulking or ultrasonic welding, for example, as a transport lock provided.

For the two housing parts - housing 3 and wall part 8th - Are easy to produce parts whose sealing surfaces 5 . 7 are easily accessible and therefore easy to work on, or in case of tool-related parts are easy to check their functionality.

2 shows a section through the clutch slave cylinder 1 the Figure 1 along the channels 19 , The pressure connection 11 leads over the pressure feed 20 the pressure medium in the annular groove 15 to. From there it gets over the channels 19 the pressure chamber 10 fed.

LIST OF REFERENCE NUMBERS

1

Clutch slave cylinder

2

axis of rotation

3

casing

4

guide sleeve

5

sealing surface

6

groove ring seal

7

sealing surface

8th

wall part

9

annular piston

10

pressure chamber

11

pressure connection

12

release bearing

13

recess

14

approach

15

ring groove

16

poetry

17

approach

18

poetry

19

channel

20

pressure feed

Claims (7)

Clutch slave cylinder (1) in the form of a arranged around a transmission input shaft Zentralausrückers with a housing (3) with a pressure chamber open on one side (10), in which an axially displaceable annular piston (9) is received and the radially inwardly by a transmission input shaft arranged around the guide sleeve ( 4) and radially outwardly by a ring-cylindrical wall part (8) is formed, wherein the wall part (8) is received as a separate component in the housing (3), characterized in that the wall part (8) at its in a receptacle (13) facing an end face an annular disc-like projection (17) into the pressure chamber (10) which is axially sealed against a rear wall of the housing (3) and the annular disc-like projection (17) on the guide sleeve (4) is supported. Clutch slave cylinder (1) to Claim 1 , characterized in that the wall part (8) has an axial projection (14) which is inserted into the receptacle (13) of the housing (3) without additional axial securing. Clutch slave cylinder (1) to Claim 2 , characterized in that the axial projection (14) relative to the housing (3) is axially and radially sealed. Clutch slave cylinder (1) to Claim 3 , characterized in that at least one channel (19) for a pressure connection (11) opening into the pressure chamber (10) is provided on the axial projection (14), wherein the axial projection (14) is provided on both sides of the at least one channel (19). axially spaced over the circumference for receiving (13) of the housing (3) is sealed. Clutch slave cylinder (1) to Claim 4 , characterized in that the wall part (8) to the pressure port (11) towards an annular groove (15), from which the at least one channel (19) puncture in the pressure chamber (10) is guided. Clutch slave cylinder (1) according to one of Claims 1 to 5 , characterized in that at least one of the parts wall part (8), housing (3) is made of aluminum. Clutch cylinder (1) according to one of Claims 1 to 6 , characterized in that at least one of the parts wall part (8), housing (3) is made of plastic.

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