GB2217798A

GB2217798A - Method for balancing friction clutch assembly

Info

Publication number: GB2217798A
Application number: GB8907438A
Authority: GB
Inventors: Hans Gryska
Original assignee: Fichtel and Sachs AG
Current assignee: ZF Friedrichshafen AG
Priority date: 1988-04-02
Filing date: 1989-04-03
Publication date: 1989-11-01
Anticipated expiration: 2009-04-03
Also published as: FR2629594B1; DE3811213A1; GB2217798B; FR2629594A1; GB8907438D0; ES2013133A6

Description

2217798 1 C METHOD FOR BALANCING CLUTCH PRESSURE PLATES The invention

relates to a method for balancing complete clutch pressure plates by removing material in the region of the external diameter of the clutch cover.

A method is already known from DE-PS 3,430,325 for removing elements pressed forward on a clutch cover, according to need, in order thus to produce balancing. This method is not practicable in all cases, since both the size and the location of these removable components are fixed. Thus the balancing can be effected only in stages, and is not exact enough for all cases.

An object of the present invention is to produce a method which renders possible as exact a balancing as possible of a pressure plate.

According to the present invention there is provided a method for balancing a clutch pressure plate consisting at least of clutch cover, presser plate and clutch main spring, in which the clutch pressure plate is driven in rotation about its clutch rotation axis and the angular position and magnitude of an unbalance are ascertained, and then for the elimination of the unbalance at least one material piece is removed from the region of the external circumference of the clutch cover, characterized in that the material piece is cut out of the marginal region of the clutch cover by a cutting operation starting from a marginal edge of the external circumference of the clutch cover and 2 progressively returning to the marginal edge.

The balancing can be carried out steplessly to the desired extent by a stepless removal of material, starting from the outer edge of the clutch cover, in circumferential zones specially pre-determined for this purpose. Thus it is possible to achieve a one hundred per cent balancing in one balancing operation on the already completed pressure plate.

In an advantageous manner here the pre-determined region is formed in the radial direction by the edge of the clutch cover extending parallel to the friction surface and in the circumferential direction by successive securing zones of the clutch cover, possibly with the exception of the zones around set pin bores. No weakening of the clutch cover results in these pre-determined zones by the removal 3 of material for balancing.

The removal of material can take place for example by shearing off with a substantially round punch tool, whereby recesses resembling circle segments are produced.

It is however readily possible to effect the material removal by a waterjet cutting operation. Likewise it is readily possible to carry out a laser cutting or plasma cutting operation for the material removal.

The invention will next be explained in detail by r,eference to an example of embodiment. Individually FIGURE 1 shows the partial elevation of a clutch pressure plate; FIGURE 2 shows the section II - II according to Figure 1.

Figures 1 and 2 show a clutch pressure plate 1, consisting of a clutch cover 2 shaped from sheet metal, which is connected fast in rotation but axially shiftably with a presser plate 3, in a manner not shown further. Between the presser plate 3 and the cover 2 a diaphragm spring 4 is arranged which bears with its external diameter on the presser plate 3 and with a middle diameter, through wire rings 7 and distance bolts The individual spring tongues 5 herepoint radially inwards. The as may be seen especially from -1 1 1 6, on the clutch cover 2. of the diaphragm spring 4 clutch cover 2 comprises Figure 1 - a plurality of zones on the external circumference, thus for example the fastening zones 11 with fastening bores 13. Through these fastening bores 13 the pressure plate is secured with screws to the fly-wheel (not shown). Circumferentially between two 4 successive fastening zones 11 a zone 9 is arranged which is suitable for the provision of the recesses 14 and 15 for balancing. This zone 9 consists of the edge 10 of the clutch cover 2, which edge extends approximately parallel to the friction face of the presser plate 3, that is perpendicularly of the axis of rotation of the clutch. This edge 10 is outwardly limited by the outer edge 8. Radially inwards the edge 10 is limited by the doming of the clutch cover 2, which is visible especially from Figure 2. If a set pin bore 12 is arranged in the edge 10 in this zone 9, at least the immediate zone around the set pin bore 12 is excepted from the provision of recesses for balancing. The pressure plate 1, after its assembly, is arranged in the working position on a balancing machine and there the amount of the unbalance and its position are ascertained. Then at the appropriate point an appropriate piece 16, 17 of material is cut out of the clutch cover 2 by a substantially round punch tool, by a cutting operation starting from the outer edge and returning in successive progression to the outer edge. Thus recesses 14 and 15 are produced which are radially outwardly open. These recesses 14 and 15 can be arranged steplessly from radially outwards and they can also be provided circumferentially steplessly on the edge 10. These recesses 14 and 15 are executed as circle segments if a substantially round punch tool is used.

The material removal can also be effected by a waterjet cutting action, a laser cutting action or a plasma cutting action. In this case the recesses 14 and 15 can have a form different from a circle segment. In every case the recesses are made radially outwardly open, can be formed steplessly and with this method a satisfactory balancing of the pressure plate can be achieved. Cutting with laser or plasma has especially the advantage that the clutch cover is not mechanically deformed and there is no fear of soiling of the clutch components.

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Claims

CLAIMS:

1. Method for balancing a clutch pressure plate (1) consisting at leastof clutch cover (2), presser plate (3) and clutch main spring (4), in which the clutch pressure plate (1) is driven in rotation about its clutch rotation axis and the angular position and magnitude of an unbalance are ascertained, and then for the elimination of the unbalance at least one material piece (16, 17) is removed from the region of the external circumference of the clutch cover (2), characterised in that the material piece (16, 17) is cut out of the marginal region (10) of the clutch cover (2) by a cutting operation starting from a marginal edge (8) of the external circumference (10) of the clutch cover (2) and progressively returning to the marginal edge (8).

2. Method according to Claim 1, characterised in that the material piece (16, 17) is cut out by means of a shearing punch.

3. Method according to Claim 1, characterised in that the material piece (16, 17) is cut out by a water-jet cutting action.

4. Method according to Claim 1, characterised in that the material piece (16, 17) is cut out by a laser cutting action.

5. Method according to Claim 1, characterised in that the material piece (16, 17) is cut out by a plasma cutting action.

6. Method according to one of Claims 1 to 5, characterised in that the material piece (16, 17) is cut out of a marginal zone (10) of the clutch cover (2) which Y T A 7 extends perpendicular to the axis of rotation of the clutch.

7. Method according to Claim 6, characterised in that the material piece (16, 17) is cut out in the form of a circle segment.

8. A method for balancing a clutch pressure plate as claimed in Claim 1 substantially as described with reference to the example disclosed herein.

k, Pubilabed 1989 at The Patent Offtoe. 9 House, W71 HIgh Holbom Lond n WC1R 4Tp. purther copies nw,be OOtalnMt MTh.

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