FR2526104A1 - Friction clutch for motor vehicle - has single axial fixing screw for assembly to drive shaft - Google Patents

Abstract

The clutch comprises a reaction plate (10) fixed to the engine drive shaft, a pressure plate (13) rotating with the reaction plate and a cover (14), all being able to be displaced axially by a spring disc (34) pivoting between the cover at a fulcrum (37) and a pressure plate fulcrum (38). The reaction plate is fixed to the drive shaft (11) by a single, central screw (46). The screw has a flat head (43) with a shoulder (45) which locates in a hole (49) in the reaction plate. The screw head has a hexagonal recess (51) for the spanner (53) which passes directly through the centre of the clutch assembly.

Description

The present invention relates generally to clutches,

  type of those usually used for

  the equipment of motor vehicles.

  As is well known, overall, such a clutch

  door at least, successively axially, a first plate, commonly called reaction plate or flywheel, intended to be secured, by fastening means, to a first shaft, in practice a driving shaft, the output shaft of the motor in the in the case of a motor vehicle, a friction disk, intended to be secured in rotation to a second shaft, in practice a driven shaft, most often the input shaft of a gearbox in the case of a motor vehicle, a second plate, commonly called pressure plate, integral in

  rotation of the reaction plate while being axially movable

  relative to this one, and a part, called a cover,

  integral in rotation of the reaction plate and connected axially-

  to it, in cooperation with resilient means which, resting on the lid, permanently urge the pressure plate towards the reaction plate, for tightening

  axial friction disc between said plates.

  To date, in the case of a clutch for a motor vehicle

  mobile, the reaction plate is usually mounted in advance, by the manufacturer of such a vehicle, at the end of the shaft, or crankshaft, the engine thereof, the means of

  the setting used for this purpose is usually

  held by a plurality of screws regularly distributed

  cularily around the axis of the assembly, while the lid, the pressure plate, and the elastic means

  associated, are assembled separately by their manufacturer and formally

  thus together a unitary unit, commonly referred to as a clutch mechanism, that the vehicle manufacturer

  must then report, by screws, on the reaction tray

  after inserting a friction disc between the latter

and the pressure plate.

  As a corollary, a dynamic balancing is to be ensured.

  At the vehicle manufacturer, it relates to the reaction plate, and at the manufacturer of clutches, it relates to the clutch mechanism to report on such a plateau.

  reaction, and possibly on the friction disc.

  Where, within acceptable limits of tolerance,

  In the event of a residual unbalance for the reaction plate and / or the clutch mechanism, the clutch mechanism that can be attached thereto must be matched to a given reaction plate, and their assembly

  relative angular orientation determines the proper

  bruage said unbalanced, after locating them.

  Optionally, after such an assembly, a final balancing operation is performed by the manufacturer of

  vehicles, to bring within acceptable tolerance limits

tables the resulting unbalance.

  Thus, for the automobil vehicle manufacturer 2 s, the establishment of a clutch usually requires today, on the one hand, two fixing operations, namely the attachment of the reaction plate of such a clutch on the

  crankshaft of an engine and the fixing of an engine mechanism

  clutch on this reaction plate after interposition of a friction disk, and, secondly, at least one, and sometimes

two, balancing operation (s).

  However, it is known, in particular from French Patent No. 1,413,803 of February 2, 1965 and its addition No. 89,060 of November 18, 1965, a provision according to which, the reaction plate being secured in advance to the lid, it is already assembled that the corresponding clutch is attached to the end of the shaft of an engine, said cover having a hub with frustoconical axial bore specific to its engagement on a complementary frustoconical extension provided for this

end effect of said shaft.

  It is therefore sufficient for the vehicle manufacturer receiving such a clutch to ensure the installation thereof on the shaft or crankshaft of an engine, and to fix the assembly in practice in conjunction with other organs. , by a screw

  single fixing, arranged axially.

  Such a screw intervenes from the outside vis-à-vis

the clutch.

  Its implementation is therefore done independently

  that of the clutch, and, in addition to a false error

  it is possible to intervene, on the part of the operator ensuring this installation, on the actual choice of the screw to be cast and in place, this establishment of such a screw still requires

a particular operation.

  In US Pat. No. 2,599,461, which concerns in

  actually a hydraulic coupling device, it is inci-

  duly represented a clutch whose reaction plateau

  is attached to the output shaft of such a coupling member

  hydraulically by means of a single central fixing screw

  sensing, on the one hand, a clean shouldered head to bear on the face of said reaction plate facing the plateau

  pressure, around a centrally arranged axial opening

  in the reaction tray and, on the other hand, a

  threaded through the latter by its said central opening.

  In such a clutch, the single fastening screw

  The work therefore intervenes from within with respect to

brayage.

  But in US Patent No. 2,599,461 in question,

  nothing indicates the modalities according to which

  the setting of this fixing screw, and, given the representation that is given, everything suggests that its tightening is done by acting on the contour

  its shoulder, and therefore before the mechanism

  corresponding clutch is reported on the

reaction concerned.

  In addition, the clutch concerned belonging to an assembly also comprising a hydraulic coupling member,

  and said assembly being generally housed in an indentary housing.

  during, everything suggests that the assembly of this assembly, and therefore the clutch, is carried out at its manufacturer, the vehicle manufacturer must in turn report the said

  together at the end of the shaft of an engine, using a

  fastening screws distributed circu- larly around

of the axis of said set.

  The present invention generally has the object of

  a provision of a nature to minimize the operations that the manufacturer of a vehicle must perform in order to put in place a clutch at the end of the engine shaft thereof

  and leading further to other advantages.

  More specifically, the subject of the present invention is a clutch, in particular for a motor vehicle,

  at least, successively axially, a first

  first tray, said reaction plate or flywheel, intended to be secured, by means of attachment, to a first shaft, in practice a driving shaft, a friction disc, intended to be secured in rotation to a second shaft, in practice a driven shaft, a second plate, said pressure plate, integral in rotation with the reaction plate while being axially movable relative thereto, and a part, said cover, integral in rotation with the reaction plate and axially connected to this, in cooperation with elastic means, which, supported on the lid,

  continually urge the pressure plate towards the

  reaction plate, for axial clamping of the friction disc between said plates, said fixing means associated with the reaction plate having a single fixing life, which, arranged axially, has, on the one hand, a clean shoulder head to bear on the face of said reaction plate facing the pressure plate, around a

  central opening arranged axially in the reaction tray

  tion, and, on the other hand, one was threaded through the latter by sadite central opening, this clutch being, following

  a first aspect, characterized in that central means

  are provided between the reaction plate and the screw of

  unique fixation that is associated with it.

  Thanks to such centering means, the radial position,

  vis-à-vis the reaction plate, and therefore the axis of the assembly.

  ble, the fixing screw associated with this reaction plate is fixed immovably from the implementation of this

  fastening screw at the clutch manufacturer.

  It is therefore possible at the manufacturer of the clutch

  ge, to definitively ensure dynamic balancing

  clutch, without being necessary, in the construction

  the vehicle, to ensure corollary, or later, any other dynamic balancing operation on

this clutch.

  The operations to be carried out by the first manufacturer

  cules for the setting up "u Lmbra; age at the end of the tree

  of a motor are advantageous -; t reduced av = an =.

  In practice, these operations advantageously represent, according to the invention, a single fixing operation, and

  this advantageously carries on a single fixing screw.

  In addition, according to the invention, this fixing screw is

  advantageously present in advance on the clutch to be fixed.

  Indeed, according to a second aspect, the following clutch

  the invention is further characterized in that, forming globally

  a unitary assembly to be reported on a shaft, it comprises in advance the fixing screw associated with its plate

of reaction.

  No error can intervene on the choice of this

  fixing screw, and the only operation actually to be

  ser is that of presenting a tool suitable for inter-

  come on this fixing screw for its implementation.

  But, as this one is already in place, this presentation

  is advantageously facilitated, and can, if desired, be easily

mechanized.

  In short, according to the invention, the cost of setting up

  of a clutch at the end of the shaft of an engine in a con-

  vehicle generator is advantageously minimized.

  The features and advantages of the invention

  from the following description,

  for example, with reference to the attached schematic drawings in which:

  FIG. 1 is a partial view in plan, with an arra-

  center, a clutch according to the invention, according to the arrow I of Figure 2; Figures 2 and 3 are views in axial section, respectively along the broken lines II-II and III-III of Figure 1; Figure 4 shows, on a larger scale, the detail of Figure 2 marked by a box IV thereon; Figures 5, 6 are partial views respectively similar to those of Figures 1, 2 and relate to an alternative embodiment; Figure 7 shows part of Figure 3 and relates to

another variant embodiment.

  Overall, and as illustrated in these figures, a

  clutch according to the invention comprises, successively axial-

  at least, in a manner known per se, a first plate, commonly known as a reaction plate or flywheel, for

  to be secured by means of fixing detailed below.

  after, to a first shaft 11 shown diagrammatically in broken lines in FIGS. 2 and 3, as well as in FIGS. 6 and 7, a friction disk 12, intended to be fixed in rotation

  to a second tree, not shown in the figures, one

  xth plate 13; said pressure plate, secured in rotation

  reaction plate 10, while being mounted axially movable relative thereto, and a part 14, said cover, integral in rotation with the reaction plate 10, and axially connected thereto, in cooperation with means resilient which, resting on the lid 14, continuously urge the pressure plate 13 towards the reaction plate 10, for axial clamping of the friction disc 12 between

  said pressure plates 13 and reaction plates 10.

  In practice, the shaft 11 is a driving shaft.

  As regards a clutch for a motor vehicle,

  it is the engine shaft of such a vehicle, or vile-

  Brequin. In the embodiment shown in FIGS. 1 to 4, the reaction plate 10 of the clutch to be brought back to the end of this driving shaft 11 is in two parts, namely, on the one hand, a support flange 15, which has an annular configuration, and which, by its inner periphery, is intended to allow to report the end assembly of said drive shaft 11, here the crankshaft, according to arrangements described

  in more detail below, while, on the outskirts of the

  dull, it has a set of teeth 17 to form the starter ring usually associated with such a plateau

  reaction, and on the other hand, a reaction

  18, which is also of annular configuration, and with which the friction disc 12 must cooperate, said reaction plate proper 18 extending in parallel.

  flange support 16, at a distance from it, in

  both axially place in place on it by legs, and being secured, both axially in rotation, to the support flange 16 by fastening means specified below. The cover 14 is also a configurational part

  annular, and at its outer periphery, it radially

  outwardly a rim 22 by which it is subjected to the reaction plate 10, thus being so integral in

  rotation of it only axially linked to it.

  In the embodiment shown in FIGS. 1 to 4, and for reasons which, not falling within the scope of the present invention, will not be described in detail here, this radial rim 22 of the cover 14 is circularly divided into

  three distinct sections, regularly distributed

is lying.

  Furthermore, in this embodiment, the fastening means securing the lid 14 to the reaction plate are constituted by rivets 23 which are also of interest.

  the two constituent parts of this reaction plate 10.

  In other words, these fastening means also ensure by themselves the joining of each of the two

  constituent parts of the reaction plate 10.

  Furthermore, an ignition target 24 with teeth 25 being provided, the latter, in the embodiment shown in FIGS. 1 to 3, presents, radially inwardly, a flange 26 through which it is interposed between the reaction plate 10 and the radial flange 22 of the cover 14, so that it is secured to the assembly by

  the same rivets 23 as before.

  In the embodiment shown in FIGS. 1 to 4, the flange 26 of the ignition target 24 has, from its place on the inside periphery, notches 27, alternating with the sections of the radial flange 22 of the ignition target 24.

lid 14.

  In a manner known per se, the pressure plate 13, which is also of annular configuration, has, from place to place, radially outward, tabs -28, which pass radially through the side wall of the cover 14, in favor of indentations 29 formed therein between the sections of its radial flange 22 and duly extended on said side wall, and by which it is coupled by rivets 30 to elastically deformable tongues 31, in practice twinned, which are extend generally substantially tangentially to a circumference of the assembly, and which, at their other end, are coupled, by rivets 32, to said sections of the radial flange 22 of the cover 14 and to the

  reaction plate 10, said rivets 32 interesting joint

  in addition to such elastically deformable tongues 31 and the radial flange portions 22 of the cover 14, the radial flange 26 of the ignition target 24 and the plate

  actual reaction 18 of the reaction plate 10.

  The pressure plate 13 is thus secured in

  rotation of the reaction plate 10 while being mobile axially

compared to this one.

  In the embodiments shown, the elastic means to which the pressure plate 13 is subjected are

  constituted by an annular piece 34, called diaphragm, which

  sensing a peripheral portion forming a Belleville washer

  35 and a fragmented central portion in radial fingers 36.

  Through its peripheral portion Belleville washer, the diaphragm 34 is supported on the cover 14, with the aid of an annular boss 37 provided for this purpose axially

  protruding on it and it carries on the plateau-de-pres-

  sion 13, with the help of an annular bead 38,

  Circularly fragmented, also planned axially

  protruding for this purpose on this one.

  By the end of its radial fingers 36, the diaphragm 34 is adapted to be subjected to a release stop 40,

  schematically in broken lines in Figures 2 and 3, also

as in figure 6.

  In the exemplary embodiments shown, it is a disengagement stopper that can intervene by pulling, that is to say in the direction opposite to the reaction plate 10,

  as shown diagrammatically by the arrow F in FIG. 2, the diameter

  the circumference along which the bead 37 of the cover 14 is greater than that of the circumference

  following which extends the bead 38 of the plateau de pres-

sion 13.

  In Figures 2 and 3, and it is likewise in Figure 6, the friction disc 12 n? been that schematized in

fine line, by its outline.

  Such a disc of frictior -s Dnnu in i L Si-m & e and not part of the -: - sen t vention it does not; will be

not described in more detail here.

  In a manner also known per se, the means of fixing

  associated with the reaction plate 10 to allow to bring the entire clutch on the driving shaft 11 to equip comprise a single fixing screw 42, which, arranged axially, has, on the one hand a shouldered head 43, adapted to bear on the face 44 of the reaction plate, and more precisely the support flange 16 that includes

  it, around a central opening 45 arranged axially-

  In this support flange 16, and on the other hand, a thread 46 passes through the support flange 16 of the reaction plate 10 by means of a central opening sadite 45, for cooperation with a tapped bore 48 arranged axially for this purpose.

end of said driving shaft 11.

  In the embodiments shown, the single fixing screw 42 is directly supported on the flange of

  support 16 of the reaction plate 10 by its shouldered head 43.

  According to the invention, centering means are provided between the reaction plate 10 and the single fixing screw

42 associated with it.

  In the embodiments shown, these centering means result from the fact that the fixing screw 42 has a cylindrical bearing surface 49 by which it engages, with a soft friction, with the central opening 45 of the reaction plate 10, this bearing cylindrical 49 being radially recessed relative to the shoulder head 43, and extending in

practice from this one.

  Preferably, the axial length L of the cylindrical bearing surface

  49 that thus presents the fixing screw 42 is sufficient

  so that this fixing screw 42 does not escape the central opening

  tread 45 of the reaction plate 10, if, during handling

  tion of the clutch before its assembly, it comes to slide axially in this central opening 45, given the axial displacement d which it then has within this clutch before coming into abutment against the hub of the disc

friction device 12, FIG.

  In practice, it is sufficient if the axial length L is

  superior to axial detachment d.

  Preferably, however, and as shown, this axial length L of the cylindrical surface 49 of the fixing screw 42 is greater than the thickness E that the reaction plate 10 has, and more precisely the support flange 16 of the -ci, at the right of its central opening 45, a length at least equal to the axial displacement d in question. Axially, the fixing screw 42 has, from its shouldered head 43, a longitudinal recess 50, which, in the embodiments shown, is a recess

blind.

  Internally, this recess 50 comprises, parallel to the axis of the fixing screw 42, at least one flat facet 51. In the embodiments shown, six planar facets 51 regularly distributed circularly are provided, the longitudinal recess 50 being thus a six-sided recess.

  As it is easy to understand, the long

  tudinal 50 of the fixing screw 42 allows the operation of

  this using any tool 53 of complementary shape.

  as shown schematically in broken lines in Figure 2.

  Preferably, and as shown, the maximum transverse dimension D 1 of the longitudinal recess 50 O of

  the fixing screw 42 is smaller than the diameter D 2 of the

  axial wise of the hub of the friction disc 12, so that the tool 53 can pass through this hub to reach the fixing screw 42, and that, therefore, the attachment of the clutch on the drive shaft 11 can be done after assembly of all the components of this clutch, friction disc

12 included.

  As a result, according to the invention, this assembly is in

  made by the manufacturer of the clutch, and the

  clutch generally forming a naritary set to report on the driving shaft 11, it comprises, in advance the

  fixing screw 42 associated with its reaction plate 10.

  Due to the centering means provided between the latter and the reaction plate 10, which prevent any inadvertent radial movement 1 by maintaining it in the axis of the set Lmbl, the dynamic balancing operation performed by the manufacturer

  the clutch is final, no radial movement intem-

  later pestifying the fixing screw 42 not being feared

at the expense of this balancing.

  Consequently, at the manufacturer of the motor vehicle, no dynamic balancing operation is to be performed.

  The only operation to be borne by the manufacturer of the vehicle

  it is therefore the only attachment of the clutch on the shaft

  11, and, thanks to the fact that the fixing screw 42 neces-

  this fixation is already present, and that it is already properly positioned in relation to the whole, this

  fixing is fast and easy and can be easily mechanized

  if desired, the tool 53 needed for its execution

  be ordered automatically for this purpose.

  Preferably, this fixing is effected by clamping elastic limit threads of the barrel 46 of the fixing screw 42, thanks to the direct support of the shoulder head 43 of the latter

  on the support flange 16 of the reaction plate 10.

  Thus a good clamping force is ensured, without it being necessary normally to implement any one

nut brake.

  However, if it becomes necessary to perfect the indes-

  rability of the fixing screw 42, a bonding can be put

  between the latter and the support flange 16 of the

  reaction vessel 10, and / or the driving shaft 11.

  In practice, in the case where, as shown, the

  clutch carries an ignition target 24, an angular indexing

  this clutch relative to the driving shaft 11 on

  which it is reported is necessary.

  In the embodiment shown in the figures

  1 to 3, this indexation is done using an indexing pawn.

  55, which is partly engaged in additional drilling.

  56 of the reaction plate 10, and more precisely the support flange 16 that includes it, and partly in a housing also complementary 57 provided for this

  effect on the driving shaft 11, at the end thereof.

  But in this embodiment, the centering of

  the clutch relative to the driving shaft hl is also done

  theirs by means of the fixing screw 42, the latter comprising for this purpose a cylindrical bearing surface 58 on which

  it is engaged, with a soft friction, with a cylindrical

  supplemental drique 39 provided for this purpose on the tree me-

* nant 11, figure 4.

  Of course, the torque transmitted from the driving shaft 11 to the clutch passes through the fixing screw 42, excluding

indexing pawn 55.

  Thus this single fixing screw 42 has a double fastening

  Axial immobilisation of the clutch and transmission

of the couple.

  Alternatively, Figures 5 and 6, the centering of the clutch

  relative to the driving shaft 11 is made using a plurality of

  centering pins 55 'regularly distributed

  cularily, three in the embodiment

represented, figure o.

  So in this case there is no centering distance between

  the fixing screw 42 and the driving shaft 11.

  The other provisions are of the same type

  than those described previously.

  In the implementation variant illustrated in FIG. 7, there is provided, on the driving shaft 11, a cylindrical surface adapted to the centering of the clutch with respect to this driving shaft 11, the reaction plate 10 coming from in engagement with this cylindrical surface 60 of the driving shaft 1 l engaging at least partially thereon by a cylindrical surface 61 radially offset from its central opening 45. Of course, the present invention is not limited to to the embodiments described and shown, but encompasses

  any variant of execution and / or combination of their di-

to elements.

  In particular, the centering vis-à-vis the reaction plate, the fastening screw associated therewith, can be done other than by a cylindrical bearing surface of this fixing screw engaged with a cylindrical surface of this reaction tray; for example, the latter may project an annular flange 7 which is then engaged and rubs c; at 1 external eriphéric,

  the shoulder head of the screw of f "t, in varia <^ e, lr nla-

  Reaction water may have in bay a plurality of pins regularly distributed around the axis of the assembly and each engaged with a soft friction in a hole of the

  shouldered head of the fixing screw.

  Finally, the field of application of the invention is not limited to that of simple clutches, to a single function disk and

  a single pressure plate but extends to

  contrary to that of multiple clutches, that is

  to say that of clutches having axially several

  friction discs and / or several pressure plates.

Claims (14)

  Clutch, in particular for a motor vehicle, of the type comprising, at least successively axially, a first plate (10), said reaction plate or flywheel, intended to be secured, by means of attachment, to a first   shaft (11), in practice a driving shaft, a disk of   tion (12), intended to be secured in rotation to a second shaft, in practice a driven shaft, a second plate (13), said pressure plate, integral in rotation with the reaction plate (10) while being axially movable by report to   this one, and a piece (14), said cover, solidary in Roman   reaction plate (10) and axially connected L to that   ci, in cooperation with elastic means (34) which took   resting on the cover (14), constantly   pressure water (13) to the reaction plate (10), for   axial clamping of the friction disk (12) between said plates   10, 13), said fixing means associated with the reaction plate (10) comprising a single fixing screw (42), which, arranged axially, has on the one hand a shoulder head   (43) adapted to bear on the face of said reaction plate   tion (10) facing the pressure plate (13), about a central opening (45) axially formed in the reaction plate (10), and secondly a threaded shaft (46) passing therethrough by sadite central opening (45), characterized in that centering means are provided between the reaction plate (10) and the single fixing screw (42) associated with it.   Clutch according to Claim 1, characterized in that the said centering means result from the fact that the fastening screw (42) has a cylindrical bearing (49) for   which it engages, with soft friction, with the opening   central section (45) of the reaction plate (10).   3 clutch according to claim 2, characterized in that the axial length (L) of said cylindrical seat (49) of the fixing screw (42) is sufficient so that it does not escape the central opening (45). ) of the board reaction (10).   Clutch according to Claim 3, characterized in that the axial length (L) of the cylindrical seat (493 of the fixing screw (42) is greater than the thickness (E).   of the reaction plate (10) to the right of its central opening the (45).   Clutch according to any one of the claims   1 to 4, characterized in that, for its implementation, the fixing screw (42) has axially a longitudinal recess (50), for example blind, having, parallel to its axis, at least one plane facet (51).   Clutch according to Claim 5, characterized in that the maximum transverse dimension (D1) of the longitudinal recess (50) of the fixing screw (42) is smaller than the   diameter (D 2) of the axial bore of the hub of the friction disk. tion (12).   Clutch according to one of the claims   1 to 6, characterized in that, forming globally a unitary assembly to report on a shaft, it comprises in advance the   fixing screw (42) associated with its reaction plate (10).   Clutch according to one of the claims   1 to 7, characterized in that, when attached to a shaft (11) by the fixing screw (42) associated with its reaction plate (10), it is centered on said shaft (11) by said reaction plate (10).   9 clutch according to claim 8, characterized in that centering pins (55 '), distributed circularly, are provided between the reaction plate (10) and the shaft (11) concerned. Clutch according to Claim 8, characterized   by a cylindrical bearing surface (61), the reaction plate   (10) is engaged with a cylindrical bearing (61) of the shaft (11) concerned.   Clutch according to any one of the claims   1 to 7, characterized in that, when attached to a shaft (11) by the fixing screw (42) associated with its reaction plate (10), it is centered on said shaft (11) by said fixing screw (42).   Clutch according to Claim 11, characterized in that the fixing screw (42) has a bearing surface (58) through which it engages with a bearing surface (59) of the shaft (11) concerned.