DE102015207797A1 - Torque limiter for an actuation system - Google Patents

Abstract

Torque limiter for an actuation system of a friction clutch comprising an at least partially made of Polyphthalamide housing with a valve chamber, wherein in the valve chamber, a diaphragm body with a diaphragm bore and at least one side hole between a stop and a Einpressstopfen is movably arranged, wherein the Einpressstopfen has at least one sealing lip, which forms a sealing seat with an end face of the visor body when the visor body contacts the Einpressstopfen. In addition, an actuating system for a friction clutch with a corresponding torque limiter is proposed.

Description

The present invention relates to a torque limiter for an actuating system of a friction clutch, wherein the friction clutch is used to interrupt a torque flow from a drive motor to a drive train of a motor vehicle.

From the DE 44 35 258 A1 is a torque limiter with a designed as a piston valve shutter valve known. The one-sided spring-loaded, inserted in a valve chamber of a housing, having a mechanical stop, piston valve forms with a valve space on one side limiting Einpressstopfen extending transversely to the axis of symmetry sealing seat, wherein the piston valve in the open position has a flow area which is greater than a cross section of a longitudinal bore in the shutter valve. The orifice valve is also provided with a bottom, in which an always open aperture bore is introduced, wherein the aperture bore has a cross section which is smaller than the cross section of the longitudinal bore.

A disadvantage of the known torque limiter is that the sealing seat between the visor body and the Einpressstopfen permitting minimal leakage flows, since the contact surface on the visor body has the smallest bumps. This increases the dispersion of the flow values through the torque limiter via different production batches. Desired, however, is the least possible scattering.

In addition, the Einpressstopfen known torque limiter made of very hard plastic polyphenylene sulfide with a 40% glass fiber content (PPS GF40) to keep a plastic deformation of the Einpressstopfens as low as possible, so that an independent release of the press connection of Einpressstopfens in the housing over the life the torque limiter is avoided. This works well with polyamide housings with a 35% glass fiber content (PA 66 GF35). Concentric Slave Cylinder (CSC) actuation systems, by contrast, use a 50% glassfiber polyphthalamide (PPA GF50 (Grivory) housing material) for their higher temperature resistance. When using polyphthalamide (PPA) and polyphenylene sulfide (PPS) cartridges, the housings often rupture because the stresses created by the interference fit can not be dissipated by plastic deformation in such housings, as is the case with PA 66 GF35 housings is. This leads to the failure of the torque limiter due to leakage.

The object of the invention is therefore to at least partially solve the problems described with reference to the prior art and in particular to provide a torque limiter which has a high durability and a low dispersion of the flow values over different production batches.

These objects are achieved with a torque limiter according to the features of the independent claim. Further advantageous embodiments of the torque limiter are specified in the dependent formulated claims. It should be noted that the features listed individually in the dependent claims can be combined in any technologically meaningful manner and define further embodiments of the invention. In addition, the features specified in the claims are specified and explained in more detail in the description, wherein further preferred embodiments of the invention are shown.

The torque limiter according to the invention for an actuating system of a friction clutch has a housing with a valve chamber, wherein in the valve chamber, a diaphragm body with a diaphragm bore and at least one side hole between a stop and a Einpressstopfen is movably arranged, wherein the Einpressstopfen has at least one sealing lip, which with a Front side of the visor body forms a sealing seat when the visor body contacts the Einpressstopfen.

A friction clutch, in particular in the manner of a single-disc dry clutch or dual clutch, serves in particular for interrupting a torque flow from a drive motor to a drive train of a motor vehicle. To operate such friction clutches actuation systems are used, which regularly have a transmitter unit and a receiver unit, which are connected to a hydraulic line. The actuating system is provided to generate a contact force or to counteract a contact force in order to enable or to solve a frictional transmission of a torque in the friction clutch. In particular, the transmitter unit has a master piston which can be moved in a master cylinder and which can be moved by a fluid, for example hydraulic oil. For this purpose, a pressure in the fluid can be built up in a slave cylinder, which causes the movement of the master piston in the master cylinder via the hydraulic line. In order to limit an excessive speed of the transmission, a torque limiter is arranged in the hydraulic line between the transmitter unit and the receiver unit, so that the speed of the transmission is throttled.

The torque limiter has a housing with a valve chamber, wherein the housing is substantially rotationally symmetrical and / or can be flowed through by a fluid. The valve space of the housing is limited, in particular in a longitudinal direction, by a (mechanical) stop, for example in the manner of a diameter step in the housing, and a press-fit plug pressed into the housing. In the valve chamber, a diaphragm body with a diaphragm bore and at least one secondary bore between the stop and the Einpressstopfen is movable. The diaphragm bore is preferably arranged in a central region of an end face and / or the at least one secondary bore is arranged on a circumference of the front side of the diaphragm body. The visor body may in particular be biased against the stop, for example by a spring. The injection plug has at least one sealing lip, which forms a sealing seat with the end face of the visor body, when the visor body contacts the Einpressstopfen. The at least one sealing lip is, in particular, an annular projection of the press-fit plug, which extends in particular in the longitudinal direction. The at least one sealing lip prevents a leakage flow of the fluid at the sealing seat, so that the torque limiter has a low dispersion for the flow values over different production batches.

In addition, it is advantageous if the Einpressstopfen at least partially made of ethylene-propylene-diene. In this case, in particular (only) the at least one sealing lip of ethylene-propylene-diene (EPDM) is configured. Alternatively, the Einpressstopfen but also completely made of ethylene-propylene-diene (EPDM) exist. This can be prevented in an advantageous manner that the housing ruptures because the Einpressstopfen is elastically deformable and thus can compensate for thermal expansion of the housing. This creates no critical strains in the housing. At the same time the Einpressstopfen to the housing and / or the visor body seals well against leakage flows.

It is also advantageous if the housing consists at least partially of polyphthalamide. The use of polyphthalamide (PPA) leads to a high temperature resistance of the housing.

Furthermore, it is advantageous if the Einpressstopfen is pressed into the housing.

Furthermore, it is advantageous if the Einpressstopfen is elastically deformable, so that thermal expansion of the housing can be compensated.

It is also advantageous if the visor body contacts the stop when it flows through the housing with a fluid in a first flow direction. The first flow direction of the fluid is in particular a direction of flow of the fluid to the receiving unit of the actuating system.

In addition, it is advantageous if the visor body contacts the press-in plug when it flows through the housing with a fluid in a second flow direction. In particular, the second flow direction is a flow direction of the fluid to the transmitter unit of the actuation system.

It is likewise advantageous if, during flow through the housing with a fluid in a first flow direction, the diaphragm bore and the at least one secondary bore of the diaphragm body are open. The cross sections of the diaphragm bore and the at least one secondary bore are greater in total than a cross section of a longitudinal bore of the housing.

Furthermore, it is advantageous if, when flowing through the housing with a fluid in a second flow direction, the diaphragm bore of the diaphragm body is opened and the at least one secondary bore of the diaphragm body is closed. The closing of the at least one secondary bore is carried out in particular by the contacting of the Einpressstopfens with the visor body. In this way, a flow through the at least one secondary bore of the visor body is prevented, in particular by the at least one sealing lip of the Einpressstopfens.

A further aspect of the invention also provides an actuating system for a friction clutch, which has a transmitter unit and a slave unit, wherein a torque limiter according to the invention is arranged in a hydraulic line between the transmitter unit and the slave unit. For further details of the actuation system, reference is made to the description of the torque limiter according to the invention.

The invention and the technical environment will be explained in more detail with reference to FIGS. It should be noted that the figures show a particularly preferred variant of the invention, but this is not limited thereto. The same components are provided in the figures with the same reference numerals. They show schematically:

1 : a torque limiter; and

2 : an actuation system.

The 1 shows a torque limiter 1 in a longitudinal section. The torque limiter has a substantially rotationally symmetrical housing 4 with a central axis 19 on. In the case 4 there is a valve room 5 in a longitudinal direction parallel to the central axis 19 through a stop 9 and a push-in plug 10 is limited. The push-in plug 10 is pressed into the housing and consists of ethylene-propylene-diene (EPDM). In the valve room 5 is a visor body 6 between the stop 9 and the push-in plug 10 arranged movable in the longitudinal direction. The visor body 6 has a blind bore 7 and a plurality of sub-holes 8th on. The aperture bore 7 is central in the visor body 6 formed and has a cross-sectional area which is smaller than a cross-sectional area of a longitudinal bore 20 of the torque limiter 1 , The sum of the cross-sectional areas of the aperture bore 7 and the majority of secondary bores 8th However, it is larger than the cross-sectional area of the longitudinal bore 20 , The visor body 6 is flowing through the housing 4 with a fluid against the stop 9 pressed, in this position of the visor body 6 the aperture hole 7 and the majority of sub-holes 8th are open. Will the housing 4 through the fluid in a second flow direction 15 flows through the diaphragm body 6 against the Einpressstopfen 10 pressed. Here comes a sealing lip 11 of Einpressstopfens with a front side 12 of the visor body 6 in contact, so one perpendicular to the central axis 19 aligned sealing seat 13 is trained. In this position of the visor body 6 is only the aperture hole 7 open.

The 2 shows a hydraulic or pneumatic actuation system 2 in which a transmitter unit 16 consisting of a master cylinder and a master piston and a slave unit 17 consisting of a slave cylinder and a slave piston via a hydraulic line 18 (or a pressure line) are connected, with the torque limiter therebetween 1 is arranged. A switching signal, which comes from a clutch pedal 25 on the encoder unit 16 is given up in its effect or speed by the torque limiter 1 limited and by means of the hydraulic line 18 on the receiving unit 17 transferred so that the receiving unit 17 on a plate spring 24 a friction clutch 3 acts, so in this case a friction package 23 the friction clutch 3 is released and a torque from an output shaft 22 around a rotation axis 21 no longer on a gear shaft 26 by means of the friction clutch 3 is transferable.

The present invention is characterized by a low dispersion of the flow rates over different production batches and a high durability.

LIST OF REFERENCE NUMBERS

1

 torque limiter

2

 actuating system

3

 friction clutch

4

 casing

5

 valve chamber

6

 visor body

7

 orifice bore

8th

 sidetrack

9

 attack

10

 Press-

11

 sealing lip

12

 front

13

 sealing seat

14

 first flow direction

15

 second flow direction

16

 transmitter unit

17

 receiver unit

18

 hydraulic line

19

 central axis

20

 longitudinal bore

21

 the rotation axis

22

 output shaft

23

 Reibpaket

24

 Belleville spring

25

 clutch pedal

26

 gear 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

• DE 4435258 A1 [0002]

Claims (10)

Torque limiter ( 1 ) for an actuation system ( 2 ) a friction clutch ( 3 ), comprising a housing ( 4 ) with a valve space ( 5 ), wherein in the valve space ( 5 ) an aperture body ( 6 ) with a blind bore ( 7 ) and at least one side hole ( 8th ) between a stop ( 9 ) and a push-in plug ( 10 ) is arranged movable, wherein the Einpressstopfen ( 10 ) at least one sealing lip ( 11 ) having an end face ( 12 ) of the visor body ( 6 ) a sealing seat ( 13 ) forms when the visor body ( 6 ) the injection plug ( 10 ) contacted. Torque limiter ( 1 ) according to claim 1, wherein the push-in plug ( 10 ) consists at least partially of ethylene-propylene-diene. Torque limiter ( 1 ) according to one of the preceding claims, wherein the housing ( 4 ) consists at least partially of polyphthalamide. Torque limiter ( 1 ) according to any one of the preceding claims, wherein the push-in plug ( 10 ) in the housing ( 4 ) is pressed. Torque limiter ( 1 ) according to any one of the preceding claims, wherein the push-in plug ( 10 ) is elastically deformable, so that thermal expansions of the housing ( 4 ) are compensable. Torque limiter ( 1 ) according to any one of the preceding claims, wherein the visor body ( 6 ) when flowing through the housing ( 4 ) with a fluid in a first flow direction ( 14 ) the attack ( 9 ) contacted. Torque limiter ( 1 ) according to any one of the preceding claims, wherein the visor body ( 6 ) when flowing through the housing ( 4 ) with a fluid in a second flow direction ( 15 ) the injection plug ( 10 ) contacted. Torque limiter ( 1 ) according to one of the preceding claims, wherein when flowing through the housing ( 4 ) with a fluid in a first flow direction ( 14 ) the aperture bore ( 7 ) and the at least one secondary bore ( 8th ) of the visor body ( 6 ) are open. Torque limiter ( 1 ) according to one of the preceding claims, wherein when flowing through the housing ( 4 ) with a fluid in a second flow direction ( 15 ) the aperture bore ( 7 ) of the visor body ( 6 ) and the at least one side hole ( 8th ) of the visor body ( 6 ) closed is. Actuation system ( 2 ) for a friction clutch ( 3 ), comprising a transmitter unit ( 16 ) and a receiver unit ( 17 ), wherein in a hydraulic line ( 18 ) between the encoder unit ( 16 ) and the recipient unit ( 17 ) a torque limiter ( 1 ) is arranged according to one of the preceding claims.

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