GB2211563A

GB2211563A - Friction clutch

Info

Publication number: GB2211563A
Application number: GB8824579A
Authority: GB
Inventors: Hans-Walter Riese
Original assignee: Fichtel and Sachs AG
Current assignee: ZF Sachs AG
Priority date: 1987-10-22
Filing date: 1988-10-02
Publication date: 1989-07-05
Anticipated expiration: 2008-10-02
Also published as: GB2211563B; BR8805469A; DE3735720A1; GB8824579D0; FR2622158B1; DE3735720C2; FR2622158A1

Description

2211563 Friction Clutch The invention relates to a motor vehicle friction

clutch, consisting of a clutch cover of sheet metal securable to a fly-wheel, while a presser plate is arranged fast in rotation but axially displaceably in the clutch cover and is loaded by a spring system towards the fly-wheel - for the frictional clamping-in of a clutch disc - while furthermore the clutch cover grasps with an axially extending, somewhat pot-shaped rim around the presser plate and lies in directly abutting manner on a fly-wheel surface extending perpendicularly of the axis of rotation.

A friction clutch of the above-stated construction type is known for example from DE-OS 226059623. In this known design, for centring between clutch cover and fly-wheel a bore is formed in a radially extending flange zone, into which bore there reaches a centring pin inserted into the fly-wheel.

As is to be seen from the prior art, the space conditions for the provision of the centring bore in the cover are extremely unfavourable.

It is therefore the problem of the invention, in friction clutches of the above-stated construction type, to provide a simply produced centring which guarantees satisfactory function even in the case of extreme lack of space - especially in the radial direction.

This problem is solved in accordance with the invention by the features of the Main Claim. By the provision of local recesses in the clutch cover at at least two circumferentially distributed points in combination with at least two centring pins inserted into the fly-wheel it is possible to achieve a simple and space-saving centring.

Claims

Further advantageous possibilities of development are laid down in the

Sub-Claims. Thus by way of example it is advantageous to arrange these recesses for the centring pins circumferentially between two adjacent cover fastening screws, while in this region the cover is drawn radially outwards and - with the exception of the recess - extends directly on the external circumference of the fly-wheel. In this way an especially spacesaving fastening in the radial direction between clutch cover and flywheel and an equally space-saving centring are produced. These recesses can be formed here by circumferentially limited incisions or cutaway portions in the cover which extend parallel and with spacing from the surface of the fly-wheel. The cut edge then occurring can be used at the same time for the axial fixing of the centring pin, if the contours of the centring pin and of the cut edge - seen in the axial direction coincide. The recesses can however also be formed by material of strip form which is applied from radially inwards to the region of the clutch cover. In this way the external contour of the clutch cover does not have to be deformed. Fastening can for example be effected by resistance welding. In all cases the centring pin is embraced by the recesses over at least about 1200 of its circumferential extent. Thus satisfactory centring can be effected with as few as two circumferentially distributed centring pins.

The invention will next be explained in greater detail by reference to several examples of embodiment. Individually:

FIGURE 1 shows the longitudinal section through the upper half of a friction clutch (Section C - D in Figure 2); FIGURE 2 shows a partial view according to Figure 1; FIGURE 3 shows a sectional view A - B according to Figure 2; FIGURE 4 shows a partial view of a further example of embodiment; FIGURE 5 shows a sectional view E - F according to Figure 4; FIGURE 6 shows a partial view of a further example of embodiment; FIGURE 7 shows a sectional view G - H according to Figure 6.

Figure 1 shows the longitudinal section through the upper half of a motor vehicle friction clutch 1. This comprises a fly-wheel 2 which is firmly connected with the crank-shaft 8 of an internal combustion engine. On the flywheel there is secured a clutch cover 3 of sheet metal, which possesses a somewhat pot-shaped rim 17 which lies with its end face on a surface 13 of the fly-wheel 2, this surface 13 extending perpendicularly of the axis 10 of rotation of the entire friction clutch. Within the clutch cover 3 a presser plate 4-is arranged which is secured fast in rotation but axially displaceably, in a manner not further illustrated, on the clutch cover 3. This presser plate 4 is initially stressed by a diaphragm spring 5 in the direction towards the fly-wheel 2. The radially inwardly - 4 pointing spring tongues 6 of the diaphragm spring 5 can be pivoted out by a release system (not illustrated) in the direction of the arrow F, whereby the entire diaphragm spring 5 is pivoted about the wire ring 11 and liberates the presser plate 4. Between presser plate 4 and surface 13 of the fly-wheel 2 there is arranged a clutch disc 7 which is mounted fast in rotation -but axially displaceably on the gear shaft 9. Especially in combination with the partial view in Figure 2 it can be seen that on the circumference of the cover 3 there are in each case provided two housing fastening screws 15 as a pair, which are arranged in the region 18 of the housing 3. This region 18 is somewhat displaced radially outwards in relation to the pot-shaped rim 17 and its zone resting on the surface 13 extends close within the external diameter of the fly-wheel 2. Circumferentially between two cover fastening screws 15 or between two openings 16 for the cover fastening screws 15 the region 18 according to Figure 3 and to the section A - B is radially inwardly provided with a recess 19, which rests without play on the centring pin 14 which protrudes from the surface 13 of the fly-wheel 2. The centring pin 14 extends parallel with the axis 10 of rotation. Thus easy production and simple axial fitting of clutch cover 3 and fly-wheel 2 are possible with for example two circumferentially distributed centring pins 14. The arrangement of the recess 19 takes place circumferentially between two cover fastening screws 15 in a region which otherwise is not used. The recess 19 here extends in such a way that an adequate clearance from the presser plate 4 remains free.

Figures 4 and 5 show a partial view and section E - F of a variant embodiment. The recess 20 represented here is achieved by an incision or cutting away of a part of the region 18, which is circumferentially limited and can be placed so that axial securing for the centring pin 14 takes place by the cut edge 22, extending parallel to the surface 13, inthe case of appropriate coincidence in the axial direction. Such a formation is distinguished for example in that the recess 20, here in strip form, must correspond in the axial direction merely to the length of the centring pin 14 protruding from the fly-wheel 2. The other parts of the clutch cover 3 with the pot-shaped rim 17 and the region 18 are not affected by the recess 20.

A further possible embodiment is reproduced in Figures 6 and 7. In this case the clutch cover 3 with its potshaped rim 17 and the region 18 was not deformed into a recess for the reception of the centring pin 14, but corresponding strips 23, preferably of metal, are fitted from radially inwards in the region 18. In this case the strips 23 are formed so that they result in a radially inward recess 21. Their securing in the region 18 can be effected for example by resistance welding. In this way it is not necessary to form the recess directly into a part of the clutch cover 3. In the present case the centring pin 14 is surrounded by the recess 21 of the strip 23 over a circumferential region of about 1800.

Claims l.) Friction clutch for a motor vehicleg comprising a fly-wheel (2) having an abutment face (13) extending perpendicularly of its axis (10) of rotation; a substantially pot-shaped clutch cover (3) shaped from sheet metal and detachably secured to the fly-wheel (2), which cover rests in abutting manner-o'n the abutment face (13) of the fly-wheel (2) with an axial end edge of its axially extending circumferential wall (17); a presser plate (4) arranged axially movably in the clutch cover (3); a clutch friction disc (7) axially between the fly-wheel (2) and the presser plate (4); a clutch spring system clamping the clutch friction disc (7) in between the fly-wheel (2) and the presser plate (4); several centring pins (14) inserted into the fly-wheel (2) parallel with the axis (10) of rotation, with which pins there are associated,, for the centring of the clutch cover (3) in relation to the axis (10) of rotation. centring elements (19; 20; 21) protruding radially inwards from the circumferential wall (17) of the clutch cover (3), characterised in that the centring elements are formed as radial recesses (19; 20; 21) which extend with their surface both in the axial direction and in the circumferential direction of the circumferential wall (17) of the clutch cover (3) and surround the associated centring pins (14) on the side adjacent to the axis (10) of rotation over an angular range of at least 1200.
2.) Friction clutch according to Claim 1, characterised in that for the securing of the clutch cover (3) on the fly-wheel (2), screws (15) arranged side by side by pairs in the circumferential direction are provided radially within the circumferential wall (17), in that the circumferential wall (17) is domed radially outwards in the region of the screw pair (15) and here extends substantially directly along the external circumference of the fly-wheel (2), and in that the recesses (19; 20; 21) are placed between the screws (15) of the pair.
3.) Friction clutch according to Claim 1 or 2, characterised in that the recesses (20; 21) are formed by centring strips which extend only over a part of the axial height of the circumferential wall (17) of the clutch cover (3).
4.) Friction clutch according to Claim 3, characterised in that the centring strips (20) are shaped integrally out of the sheet metal of the circumferential wall (17) by incisions (22) or cut-away portions limited in the circumferential direction and parallel to the marginal edge of the circumferential wall.
59) Friction clutch according to Claim 4, characterised in that an edge (22) of the circumferential wall (17), formed by the incision or cut-away portion, radially overlaps and axially fixes the centring pin (14).
6.) Friction clutch according to Claim 3, characterised in that the centring strip is formed as a material strip (21) set upon the inner side of the circumferential wall (17).

8
7.) Friction clutch for a motor vehicle substantially as described in the examples shown in Figures 1 to 3, 4 and 5 or Figures 6 and 7 of the accompanying drawings.

1 tl Published 1989 at The Patent Oftice. State House, 66P71 High Holborn, London WC1R 4TP. Further copies maybe obtainedfrom The Patent Ofnce. Sales Branch, St Mary Cray. Orpington. Kent BR5 3RD. Printed by Multiplex techniques ltd, St Mary Cray. Kent. con. 1187