FR2847317A1 - Spring diaphragm for clutch mechanism of motor vehicle, has nozzles that surround central opening and form tracks that includes plane track forming interior radial track and convex track placed adjacent to plane track - Google Patents

Abstract

The diaphragm has a conical elastic disc that is cut out in the interior to form radial fingers (12) resulting from an external crown of the disk. Nozzles of the disc surround a central opening (14) and form a track for a range of obstinate clutch. The nozzles have a plane track (13b) that forms an interior radial track and a convex track (13a) placed adjacent to the plane track. An Independent claim is also included for a clutch mechanism including a spring diaphragm.

Description

Diaphragm spring for friction disc clutch mechanism

  motor vehicle The invention relates to a diaphragm spring for a mechanism

  motor vehicle disc clutch.

  A disc clutch spring 10 has been known since the 1950s, called a diaphragm spring, consisting of a substantially conical elastic disc, the inside of which is cut along radii to form radial fingers from the outer ring of the disc. and whose free ends or spouts surround a central orifice. The outer crown forms a Belleville washer. Reference may be made to documents US 2630897, FR 2748970, FR 2808057 or FR 2813932 to see several embodiments of diaphragm spring, and their integration into a clutch mechanism. The shape and number of the fingers can in particular vary.

  A conventional clutch mechanism using this diaphragm is constituted as follows: a pressure plate pushed by the diaphragm spring presses, in the engaged position, the clutch disc on the motor plate linked to the motor shaft, thus making the rotation integral engine plate and the clutch disc locked in rotation by splines on a shaft (the primary shaft of the gearbox) which is thus driven. A cover forms permanent rear supports on the radial fingers of the diaphragm, towards the crown. When an annular stop comes in the disengaged position, press the center of the diaphragm on the nozzles of the diaphragm spring, the fingers rock on the rear supports and cause the diaphragm crown to recede and therefore disengage the clutch disc 30 and of the engine plate. When the stop returns to its normal position, the spring force of the diaphragm brings the crown back into contact, with constant force, on the clutch disc.

  The stop can be controlled mechanically, hydraulically

or electrically.

  In most mechanical controls, the beaks of the fingers intended to serve as a support for the clutch stop are simply formed by the natural end of the finger, flat, even if the body of the finger itself can be curved, for example in the document FR

2813932.

  In most hydraulic controls and sometimes in mechanical controls, the beaks of the fingers are themselves curved, just at the end, and the abutment is supported at the convexity of the beak. This is shown for example in US documents

  1o 3939951, US 6360863 or FR 2812918.

  There are therefore two types of diaphragm depending on whether one wishes to use tracks of flat or curved bearing surfaces. This forces a doubling of references and stocks, and the risk of supply errors. The invention aims to remedy this

problem.

  The invention achieves its object by means of a diaphragm spring of a disc clutch mechanism, consisting of a substantially conical elastic disc, the inside of which is cut along spokes to form radial fingers from the outer ring of the disc and of which The free ends or spouts surround a central orifice, the spouts forming a track for a clutch release bearing surface, characterized in that the spouts comprise two successive adjacent tracks of different profile.

  Preferably, the radially innermost track is a flat track and the adjacent track is a curved track, but other forms of

tracks could be used.

  Thanks to this standardization of the diaphragm nozzles, it is possible to mount the same diaphragm spring whatever the clutch control that is going to be installed; the diameter of the bearing surface of the hydraulic control 30 simply has to be slightly greater than the diameter of the control surface

  mechanical, which is already generally the case.

  Other characteristics and advantages of the invention will emerge on reading the description which follows, with reference to the appended drawings in which:

  FIG. 1 is a perspective view of a diaphragm spring of the invention and its cover, FIG. 2 is a diametrical section of the spring and of the cover of FIG. 1, FIG. 3 is a sectional view schematic of a clutch control by cable of the prior art, FIG. 4 is a more detailed view in half section of the diaphragm and of the members adjacent to the control of FIG. 3, FIGS. 5 and 6 are views similar to Figures 3 and 4 but

  concerning a hydraulic clutch control.

  We will first describe the known commands with reference to

Figures 3 to 6.

  The clutch control essentially comprises a friction assembly symbolized at 1 on which a diaphragm spring 15 10 can be supported, held in a cover 20 screwed to the flywheel 50 secured to the drive shaft, not shown. The support of the diaphragm spring 10 is a function of the axial displacement of an annular clutch stopper 30. The friction mechanism 1 comprises the annular friction disc 2 with its grooved friction hub 3 integral in rotation with the driven shaft 4. The annular disc 2 is intended to engage by friction on the motor plate 50 to which it is adjacent, when it is pushed by the pressure plate 5. The pressure plate 5 is itself pushed, on bosses of support 6, by the marginal crown 11 of the diaphragm spring 10, which crown bears internally on support bosses 21 of the

cover 20.

  The diaphragm spring 10 comprises, in addition to the crown 11, a plurality of radial fingers 12 whose ends or nozzles 13, intended to cooperate with the stop 30, leave a central orifice 14 for the passage of the shaft 4.

  In a cable control (Figures 3 and 4), the displacement of the stopper 30 is obtained mechanically, thanks to the clutch cable 31 connected to the clutch pedal, actuating a clutch release fork 32 pivoting on an axis 33 and pushing by its fork end 34 at the rear of the stop 30 so as to move it towards the diaphragm spring

  , in the declutching position; it is the return force of the diaphragm spring 10 which brings the stop 30 and the clutch pedal back into the engaged position.

  In a hydraulic control (Figures 5 and 6), a pipette 35 of a hydraulic control circuit sends a pressurized fluid into a chamber of a cylinder 36 capable of pushing the annular stop 30 towards

the diaphragm spring 10.

  Currently, the shape of the spouts 13 intended for the cable control is generally that of a simple flat support tongue, in the extension of the finger 12, as shown in FIG. 4.

  1o that of the spouts 13 intended for hydraulic controls is generally a convex shape, as shown in FIG. 6, the bearing on the bearing then being made by the top of the convexity.

  Figures 1 and 2 show the diaphragm spring 10 of the invention and the same reference numerals have been used to designate the parts already identified in Figures 3 to 6. The diaphragm spring 10 always comprises a crown 1 1 receiving the support 21 of the cover 20, and of the fingers 12 internally terminated by a spout or end 13 surrounding an orifice 14. The end 13, intended to support the clutch stop, is of short length compared to the total length of the finger 12, typically

  less than half, preferably less than a third.

  According to the invention, the spout 13 is made up of two successive different profiles 13a and 13b, respectively curved and in simple flat tongue, going from the outside towards the inside. In this way, it is possible to use the convex profile 13a with a hydraulic control stop, and the profile 13b with a cable control stop, the only condition being that the diameter of the cable control stop is smaller. the diameter of the hydraulic control stop.

  Naturally, the invention which has been described in the context of a conventional clutch, with pressure plate + mechanism + diaphragm + friction, also applies to any other type of clutch using the diaphragm spring, in particular the clutch double damping flywheel, or clutches with automatic wear adjustment.

Claims (3)

  1. Diaphragm spring (10) of a motor vehicle disc clutch mechanism, consisting of a substantially conical elastic disc, the inside of which is cut along spokes to form radial fingers (12) coming from the outer ring (11 ) of the disc and whose free ends or spouts (13) surround a central orifice (14), the spouts (13) forming a track for a clutch release bearing surface (30), characterized in that the spouts (13) have two tracks   adjacent successive (13a, 13b) of different profile.   2. Spring according to claim 1, characterized in that the radially innermost track is a flat track (13b) and the adjacent track is a curved track (13 a).   3. Clutch mechanism characterized in that it comprises a spring   diaphragm (10) according to any one of claims 1 or 2.