FR2660035A1 - Clutch device for an automatic gear change for motor vehicles - Google Patents

Abstract

(a) Clutch device of an automatic gear change for automobiles; b) Clutch device characterized in that it comprises a wavy spring (11) consisting of a thin elastic metal strip wound in a spiral in the direction of thickness while continuously shaped wavy parts so that the ridges and valleys of the adjacent corrugated parts (11a) are mutually opposed, this corrugated spring (11) being used as a return spring (10) and fixed, by one of its ends, to an annular retaining element; c) The invention relates to a clutch device for an automatic gear change for automobiles.

Description

"Clutching device for a gear change

  The present invention relates to a clutch device incorporated into an automatic gear change for automobiles, characterized in that it comprises a corrugated spring consisting of a thin elastic metal band spirally wound in the direction of rotation. the thickness while continuously forming corrugated portions so that the peaks and valleys of the adjacent corrugated portions are mutually opposite, said corrugated spring being used as a return spring and secured at one end thereof to a

annular retainer.

  According to another characteristic of the in-

  vention, a turn of the seat at one end of the return spring is made so as to have the same shape as that of the holding member by

  in relation to the central axis of the latter, so that

  the turn of the seat can serve as a restraint.

  When the opposite seat turns of the seat

  return spell mounted in the clutch device

  according to the invention are subject to a predetermined load

  the corrugated parts are deformed elastically

  to produce a deviation of predetermined length, and when the load is removed, the

  Wavy parts expand to take their shape.

  The shape of the return spring is such that

  the charge to be applied is equal to the sum of the

  each applied to the respective springs of the prior art, and so that the deflection is

  equal to that of each coil spring.

  The invention will be described in detail with reference to the accompanying drawings in which: Figure 1 is a perspective view of a return spring used in a clutch device according to the present invention; FIG. 2 is a perspective view

  a return spring that eliminates the need for

the corresponding retention element;

  FIG. 3 is a diagrammatic view

  sensing the positions of a number of clutches used in an automatic shift; FIG. 4 is a perspective view

  exploded elements of a conventional clutch device

if that;

  FIG. 5 is a perspective view

  presenting the manner in which a

  positive conventional return springs; and FIG. 6 is a sectional view as follows

  line VI-VI shown in FIG.

  Automatic shifting A

  presented in Figure 3 is a mechanism for ef-

  automatically perform the starting and shifting of an automobile, this device comprising a number of clutch devices 20, 30 and

  mounted in it, although the number of

  clutch depends on the type of change

of speed.

  As shown for example in Figure 4, the

  clutch device 20 comprises parts 21 as-

  associated with the clutch drum, a device for

  reminder 22, a retaining device 23 and

  parts 24 such as annular plates

  very clutch devices 30 and 40 are exactly like the clutch device 20 being constructed. The return spring device used in a conventional clutch device comprises a number (generally 8 to 20) of coil springs 22a which, as shown in Figures 5 and 6, are circumferentially spaced apart by equal distances.

  on a retaining element 23, one of their extremes

  respective parts fitting on each part of

Cylindrical 23 a.

  In a conventional clutch device, the

  return spring device comprises a relative-

  large number of coins, which constitutes a

  from the economic point of view, and, as each

  each of the cylindrical fixing parts 23 has

  retaining piece 23 is provided with a flange 23 'for

  fish the coil spring to escape

  this flange being flared to a diameter greater than

  inner diameter of the coil spring 22a, the operation

  fixing the coil springs 22 a to the elec

  23 is complicated because a number of

  Many of these coil springs must be attached one by one to the retaining element. Thus, this operation takes a long time so that the

mounting is very weak.

  In addition, there are variations in

  bridging in the free height of the coil springs

  Consequently, when a number of these coil springs are combined and mounted in place,

  it is difficult to obtain a single support force

  around the circumference of the retaining element

  naked If such a device springs is incorporated

  in a clutch, this device has the disadvantage

  deny disrupting the operation of the clutch.

  As shown in FIG. 1, a return spring 10 according to the present invention, used in a clutch device, comprises a corrugated spring 11

  consisting of a thin metal band such as a ban-

  of spring steel of predetermined length and having a characteristic of elasticity, this metal strip being spirally wound in the direction of the thickness while continuously forming successive corrugated portions 11a, and coils of

  seat 12 formed by winding the ends annul-

  opposing menses of the corrugated spring 11 so that the ridges and troughs of adjacent corrugated portions

  11 of the corrugated spring 11 are oppo-

  his. The return spring 10 constructed in this manner expands and contracts by elastic deformation of the corrugated portions 11a of the corrugated spring 11, using the elasticity of the thin metal strip. Thus, when the opposite seat turns 12 are subjected to load, the corrugated portions 11a of the corrugated spring 11 are subjected to a deflection in

  elastically deforming, this deviation takes place

  In this state, if the load ceases to be applied to the opposite seat turns 12, the corrugated wave portions 11a of the waved spring will assume their shape by expanding in the direction of rotation. sense of increasing

the height of the waves.

  In addition, as the return spring 10 se-

  According to the invention, a thin metal strip can be used, a large deflection can be obtained. Moreover, a desired load can be obtained due to the rigidity of the corrugated portions 11a of the corrugated spring 11.

  concerning the method of fixing the spring of

  10 to the retaining element 13, it is possible to spot weld or crimp an end of the return spring 10 on the retaining element 13. FIG. 2 represents another embodiment of the invention in which a turn of seat 12 located at one end of the return spring

  is designed to act as a retention element

  naked; thus, one can do without the retaining element 13. The table below gives a comparison between the prior art (clutch using 20 springs

  helicoidal) and return springs according to

this invention.

  1 prior art (number of helical springs

  coidals: 20) 2 Present invention 1 3 Present invention 2

  4 Inside diameter of the retaining element

  The clutch device according to the invention requires a reduced number of elements and takes less time to assemble, which leads to a reduction in costs. Moreover, as a thin metal strip is used, it is possible, for the same load, to obtain a deviation of greater amplitude than in the case of conventional coil springs Thus, one can make more compact the shape of the return spring

  in the direction of the length of this spring.

  Finally, when using the reporting

  pel according to the invention in a clutch, there is more

  risks that the support force becomes irregular

  because of manufacturing variations in the

  free coil springs, which allows

  thus improve the operation of the clutch.

  Previous Art Presenting I Introducing i nven Li on-2 (number of elucdidao remiarts: 20) (Re 53 ori undule) Intemal Diameter of the ee'menfr 'c = retention o' mm 9 5 Largejr of the e / 6 I re / enuemm I 8 heel springs Jal of the spring of the spring of the spring mm 8, 3 9 5 9 5 Spring constant kf f / mm 20 XO 345 = 6, e 9 N / mm} {68} _ Author free mm 3 7, 5 Deviation -the trivial 7 il max mm I 7, 5 Workload k Rf 1 2 O maxmum k Nf} {II 1 86} Cowtrain tt trmvd; I kgf / mm 2 8 8 90 kf 8 8 90 m, ax u, '-' {N / mme} {862} {892} D; ameter of f; l mm 11 2 Plate grinder x Width of ply mm O, 7 X 1 7 0.9 XI 1 W. m 6 re total I turns 1 2, 5 1 5, O 1 6, 5 t Effective number of turns IO, 5 I 3, OI 4, 5 OI 14 9 Reduction of reducton A complete conftraction compared to springs 3 O htl, 'co;' uk Number of booster shock absorbers 2 O I 1 Ix

Claims (2)

R E V E N D I C A T IO N S   1) clutch device characterized in that it comprises a corrugated spring (11) consisting of a thin elastic metal strip spirally wound in the direction of the thickness while forming continuously corrugated portions so that the peaks and valleys of adjacent corrugated portions (11a) are mutually opposite, said corrugated spring (11) being used as a return spring (10) and secured by   one of its ends to an annular restraint lar.   2) Clutch device according to the   cation 1, characterized in that a turn of the seat   at one end of the return spring (10) is   aligned so as to have the same shape as that of the retaining element with respect to the central axis thereof, so that this turn of seat can serve as a restraint.