Hydrokinetic coupling apparatus with lock-up clutch for motor vehicle

The present invention concerns hydrokinetic coupling appliances, notably for motor vehicles, equipped with a locking clutch, usually referred to as a “lock-up” clutch, for mechanically making their turbine wheel and their impeller wheel integral with respect to rotation, as described for example in the document FR-A-2 726 620.

In this document, the hydrokinetic coupling appliance has, inside a sealed casing, filled with oil, a torque converter with a turbine wheel and an impeller wheel, and a lock-up clutch.

In general terms the casing has a first half-shell provided with an axially fixed transverse wall by means of which it is connected to the driving shaft. The turbine wheel is connected to an internally fluted hub for rotatably connecting it to a driven shaft.

The first half-shell, and therefore the casing, forms the input element of the hydrokinetic coupling appliance which is rotary in operation, whilst the hub forms the output element of the said appliance.

Being a case of an application for a motor vehicle, the driving shaft consists of the crankshaft of the vehicle engine, whilst the driven shaft consists of the input shaft of the transmission box.

The lock-up clutch has at least one friction lining which, fixed with respect to rotation to the turbine wheel and hub, either directly, or indirectly by means of a torsion damper, is disposed axially between on the one hand the said transverse wall fixed with respect to the impeller wheel and on the other hand a piston which is mounted so as to be able to move axially with respect to the transverse wall forming a counter-piston. This piston is rotatably connected to the transverse wall, usually by elastic tongues substantially elongated tangentially to a circumference of the whole. This type of circumferentially acting tongue will hereinafter be referred to as a tangential tongue.

These tongues are mounted inside a variable-volume control chamber delimited on the one hand radially externally by the friction lining and radially internally by a cylindrically shaped centring device adjacent to the transverse wall and on the other hand axially by the piston and transverse wall.

These tongues are fixed at one of their ends firstly in a fluidtight manner to the transverse wall of the casing, either directly or by means of a driving piece which is separate or in a single piece with the tangential tongue.

This fixing is easy to achieve, for example by means of rivets issuing by extrusion from the transverse wall.

Next the other end of the tongue is fixed to the piston. Having regard to the location of the tongues in the control chamber, this fixing is effected by means of two-part fixing members, for example a rod with a shouldered head mounted in the control chamber.

This rod passes, with radial clearance, through the piston and is connected by crimping to a ring situated outside the control chamber.

The rod is fixed to the tongues. Thus the fixing is effected by acting on only one side of the outside of the control chamber and by breaking the rod.

The fixing members are therefore relatively expensive and it is necessary to have recourse to a traction tool for breaking the rod and a crimping tool for crimping the ring on the notched rod.

The object of the present invention is to mitigate this drawback, in a simple and economical fashion.

An aim of the invention is therefore to fix the elastic tongues to the elastic fixing member of standard type, whilst locating the tongues in the control chamber.

According to the invention, a lock-up clutch of the type indicated above in which the elastic tongues are fixed on the one hand at one of their circumferential ends by first means of fixing to one of the transverse wall/piston pieces, referred to as the first piece, and on the other hand at the other one of their circumferential ends by second means of fixing to the other one of the transverse wall/piston pieces, referred to as the second piece, is characterised in that the first piece has passage holes coinciding axially with the second fixing means and in that the passage holes are closed off at the end by sealing obturators.

By virtue of the invention the fixing means can be of the same type. Because it is possible to act, by virtue of the invention, on both sides of the transverse wall/piston pieces, the tongues can be fixed by bonding or welding to the pieces in question. The fixing means, in a variant, can consist of fixing members.

By virtue of the invention the fixing members are then more economical and can be of a standard type without there being any need to break a rod and to crimp a ring because, by virtue of the passage holes, it is possible to act on both sides of the second piece on the second fixing members by means, in a known fashion, of a tool and a counter-tool.

Thus the piston can be fixed to the tongues by means of simple rivets passing through associated openings in the piston with smaller radial clearance so that coupling of the piston to the elastic tongues is more certain.

The relative movements between the piston and the tongues are reduced in all cases.

The first fixing members can be identical to the second fixing members. For example, it can be a case of conventional rivets or rivets formed by extrusion from the transverse wall and the piston.

The obturators are introduced at the end, after fixing of the tongues, in the passage holes in order to close these off in a fluidtight manner.

The obturators can, for this purpose, be force-fitted, or fitted by contraction followed by expansion in the passage holes, or fixed by welding, snapping-in, screwing, deformation, crimping or bonding to the transverse wall/piston piece concerned.

Naturally, depending on whether the holes are produced in the transverse wall or the piston, it is possible to first of all fix the tongues to the transverse wall and then to the piston or in the other case first of all fix the tongues to the piston and then to the transverse wall. Naturally, passage holes can be provided in the piston and in the transverse wall.

By virtue of the invention there are therefore more possibilities, with regard to the manufacturing process, whilst having the possibility of acting axially in both directions, that is to say on each side of the piston and of the transverse wall and without using a tool for crimping a ring and breaking a rod by traction.

In one embodiment, the obturators consist of plugs.

Advantageously, the passage holes are stepped in diameter in order to form a transverse internal shoulder connecting the smaller-diameter portion to the larger-diameter portion of the passage hole.

Advantageously, the plug is also stepped in diameter whilst being shouldered, in a manner complementary to that of the passage hole. As a result the plug has a head and a body and the larger-diameter head of the plug comes to be housed in the larger-diameter portion of the passage hole and comes into abutment against the shoulder of this hole by means of its transverse shoulder connecting the head of the plug to its smaller-diameter body introduced into the smaller-diameter portion of the passage hole.

This body can be knurled for forcible introduction of the plug into the passage hole.

This body can be threaded and the smaller-diameter portion of the passage hole is then given a female thread. The plug is then screwed into one of the transverse wall/piston pieces. The plug is shorter axially than the passage hole.

It will be appreciated, when the plug with a shouldered head is introduced into the stepped passage hole of the piston, that the hydraulic pressure prevailing on the side of the piston opposite to the control chamber prevents the plug from coming out again when the lock-up clutch is engaged since the said pressure is then greater than that prevailing in the control chamber.

All this harmonises well with the dished shape of the piston increasing its strength. Naturally the elastic tongues can be inclined. In all cases they are circumferentially oriented and axially elastic.

As a variant, the obturator consists of a ring. The passage holes are then stepped in the aforementioned manner in order to form a stop shoulder for the ring immobilised by crimping, bonding, deformation or welding in contact with the shoulder.

As a variant, a sealing joint can be interposed between the shoulder and the ring. Naturally, the passage hole can be of uniform diameter. In this case, a pellet is cooled, for example to −40°, by dipping it in liquid nitrogen, and is then easily introduced into the passage hole. The pellet contracts and then expands in order to close off the passage hole sealingly. The method of fixing is also applicable to a plug.

As a variant, the obturator can be doubly stepped to form two transverse shoulders disposed on each side of a central part of smaller diameter. One of the shoulders serves as a support for the head of a plug, the free end of whose body has at least one notch coming into engagement, after passing through the central part of the passage hole, with the other shoulder for mounting of the plug by snapping in.

Advantageously, several notches are provided. These notches belong to lugs which are elastically deformable radially. The number of lugs depends on the application. A single notch can be provided. The plug is advantageously made of synthetic material, such as plastic material, so as to have the required elasticity.

The obturator can be curved originally and then flattened under force. It can be a question for example of a curved washer flattened under force in the stepped passage hole. The obturator can be in the form of a dish or pan, with an inclined rim. By forcibly mounting the obturator in its passage hole, the rim is deformed and, at the end of the travel, the bottom deformed so that the obturator is immobilised, its rim being in contact with one of the faces of the piston or of the transverse wall whilst its bottom is in contact with the other face of the piston or of the transverse wall.

The dish is, in one embodiment, carbonitrided and is therefore deformed on mounting by jamming in its mounting hole.

As a variant, the dish is stepped in diameter to form a shoulder. A Belleville washer is mounted in the dish. The external periphery of the Belleville washer being in contact with the shoulder, it is turned over in contact with the bottom in order to ensure locking of the obturator.

The obturator is, in one embodiment, provided with a recess at its external periphery for receiving a sealing joint coming into contact with the edge of the passage hole. In all cases, a perfect seal is obtained. In general terms, a joint can be associated with the obturator.

Usually the piston is mounted on a centring device interposed between the transverse wall and the hub fixed to the turbine wheel of the hydrokinetic coupling appliance.

The hub is fluted internally for connecting it with respect to rotation with the driven shaft, whilst the centring device has on the one hand at its centre a blind hole in communication with the driven shaft, provided internally with a feed channel, and on the other hand passages for connecting the blind hole to the control chamber.

By virtue of the invention, the piston can be mounted on the hub of the turbine wheel.

More precisely, according to one characteristic, the hub has on the one hand an internally fluted socket entering a blind hole in the centring device and on the other hand, parallel to its socket and radially beyond it, a radially oriented annular rim whose external periphery forms a guide surface for the piston, a sealing joint acting between the said rim and the piston.

By virtue of this arrangement the axial bulk is reduced and a sealing joint is saved.

This is because it would have been possible to create the guide surface on the centring device, hereinafter referred to as a ring, and in this case it would have been necessary to provide a joint at the guide surface and another joint at the hub in order to prevent, when the lock-up clutch is engaged, oil passing between the hub and the ring.

Here, with a single joint, there is a perfect seal, equally well when the lock-up clutch is engaged or disengaged.

According to another characteristic, an annular recess being formed between the rim and the socket, the ring enters inside the recess.

Thus the hub and ring are fitted together, so that the axial bulk is reduced.

The description which follows illustrates the invention with regard to the accompanying drawings, in which:

FIG. 1

is a partial half-view in axial section of the hydrokinetic coupling appliance showing the lock-up clutch according to the invention;

FIG. 2

is a view to a larger scale of the bottom part of

FIG. 1

with depiction of the components of the torque converter;

FIG. 3

is a partial front view of the guide ring with lugs of the torsion damper forming part of the lock-up clutch;

FIG. 4

is a partial view in axial section showing, to a large scale, one of the plugs closing off the transverse wall;

FIGS. 5 and 6

are views similar to

FIGS. 1 and 3

for a second example embodiment;

FIG. 7

is a view similar to

FIG. 1

for a third example embodiment;

FIG. 8

is a partial view similar to

FIG. 1

for a fourth example embodiment.

FIG. 9

is a partial view in section showing an obturator in the form of a plate fixed by crimping in its passage hole;

FIG. 10

is a view similar to

FIG. 9

, the plate being fixed by brazing in its passage hole;

FIG. 11

is a view similar to

FIG. 10

in which the plate is fixed by deformation in its passage hole;

FIG. 12

is a view similar to

FIG. 9

, in which the obturator consists of a plug housed in the thickness of the piston;

FIG. 13

is a view similar to

FIG. 12

in which the obturator consists of a pellet;

FIG. 14

is a view similar to

FIG. 9

in which the obturator is a plug with a curved head;

FIG. 15

is a front view of a plug provided with a joint;

FIG. 16

is a view in axial section of a plug provided with a sealing joint along the line

16

in

FIG. 15

;

FIG. 17

is a view similar to

FIG. 9

in which the obturator consists of a pan or dish;

FIG. 18

is a view similar to

FIG. 17

for yet another example embodiment;

FIG. 19

is a half view similar to

FIG. 17

for yet another example embodiment;

FIG. 20

is a partial view showing the rim of the pan in

FIG. 19

before its deformation;

FIG. 21

is a view in axial section of a hydrokinetic coupling appliance for a variant embodiment with obturators reversed compared with those in

FIGS. 1

to

4

;

FIG. 22

is a partial view, to a larger scale, of

FIG. 21

, showing the fixing of the tongues;

FIG. 23

is a view similar to

FIG. 1

for another example embodiment;

FIG. 24

is a view in the direction of the arrow

24

in

FIG. 23

in the piston for showing the drive piece;

FIG. 25

is a view in section along the line

25

—

25

in

FIG. 24

;

FIG. 26

shows in perspective the damper plate and the disc in FIG.

23

.

The hydrokinetic coupling appliance depicted in the figures is able to rotate about an axial axis of symmetry X—X and has, inside a sealed casing

10

filled with oil, a torque converter

1

and a lock-up clutch

2

provided with a torsion damper

3

.

This appliance is intended to equip a motor vehicle with an internal combustion engine.

As is known, the torque converter

1

has an impeller wheel

100

with blades, a turbine wheel

101

with blades, a reaction wheel

102

and a freewheel

103

associated with the reaction wheel

102

. All these elements are visible in FIG.

21

and partially in FIG.

2

.

The casing

10

has a first half-shell

12

and a second half-shell

16

and forms the input element of the hydrokinetic coupling appliance by means of its first half-shell

12

.

The first half-shell

12

has a wall

11

of roughly transverse orientation extended at its external periphery by an axially oriented cylindrical rim

13

.

The transverse wall

11

carries screws

112

(

FIG. 1

) for connecting it by means of nuts to a shield

113

(

FIG. 2

) fixed to a driving shaft

200

, here the crankshaft of the vehicle engine.

The blades of the impeller wheel

100

issue from the internal face of the second half-shell

16

, here attached by welding to the free end of the rim

13

, as can be seen in FIG.

21

.

For more information reference should be made to the document FR-A-2 695 975.

The blades of the turbine wheel

101

are opposite to the blades of the impeller wheel

100

.

The turbine wheel

101

is fixed at its internal periphery, by means of lugs or an annulus

104

, to a hub

5

forming the output element of the hydrokinetic coupling appliance.

This hub

5

has at its centre an internally fluted socket

50

for connecting it with respect to rotation to a driven shaft

201

, here the input shaft of the vehicle transmission box.

As is known, when the vehicle is started up, the impeller wheel

100

drives the turbine wheel

101

by virtue of the circulation of oil between the blades of the turbine

101

and impeller

100

wheels.

During this phase, the lock-up clutch

2

is disengaged or declutched, so that the torque is transmitted from the crankshaft to the first half-shell

12

and then to the hub

5

and to the driven shaft via the torque converter

1

.

Next, in order to prevent any slip between the turbine

101

and impeller

100

wheels, the lock-up clutch

2

is engaged (clutched), so that the torque is transmitted from the crankshaft to the first half-shell

12

and then to the hub

5

and to the driven shaft via the lock-up clutch

2

, whose torsion damper

3

is connected to the hub

5

and damps the vibrations generated by the vehicle engine.

To do this, the lock-up clutch

3

has here a piston

20

, roughly of transverse orientation, mounted so as to be able to move axially in a sealed fashion along an axially oriented guide surface

59

, as described below.

The clutch

2

also has two friction linings

22

disposed on each side of a drive disc

24

.

The linings

22

and disc

24

are located axially between the piston

20

and the transverse wall

11

forming a counter-piston. This wall

11

is fixed axially.

A variable-volume control chamber

23

is delimited on the one hand laterally (axially) by the piston

20

and the wall

11

and on the other hand radially on the inside by a centring device

21

, here cylindrical in shape, and radially on the outside by the linings

22

and disc

24

.

The centring device

21

is fixed to the central part of the wall

11

, as described below, and is provided at its centre with a blind hole

120

able to be fed with fluid from the driven shaft, projecting axially with respect to the second half-shell

16

.

To do this, the driven shaft (depicted in broken lines at

201

in

FIG. 2

) has its centre a feed channel, whilst the centring device

21

has passages

221

for its blind hole

120

to communicate with the control chamber

23

.

A principal chamber exists on the side of the piston

20

turned in the opposite direction to the transverse wall

11

and chamber

23

.

The centring device

21

is located axially between the hub

5

and the wall

11

, that is to say between the output and input elements of the hydrokinetic coupling appliance.

For reasons of simplicity, this centring device will hereinafter be referred to as the ring, since it is roughly in the form of a stepped ring machined at the rear, as described below. As a variant (FIG.

21

), the centring device is omitted and the passages

221

are formed in the hub

5

, guiding the piston.

By causing the pressure to vary on each side of the piston

20

, for example by varying the pressure in the chamber

23

, the piston

20

is allowed to move axially with respect to the axially fixed wall

11

, either to clamp the friction linings

22

and disc

24

between the piston

20

and wall

11

, or to unclamp the linings

22

and disc

24

.

In the first case, the lock-up clutch is engaged or clutched at the end of the axial movement of the piston

20

in the direction of the wall

11

.

In the second case, the piston

20

moves in the opposite direction to the wall

11

in order to disengage or declutch the clutch.

Here the friction linings

22

are fixed to the disc

24

whilst being for example bonded or brazed to the faces of the disc

24

on each side thereof.

As a variant, the linings are fixed to the piston

20

and transverse wall

11

.

Thus the piston offers, at its external periphery, a friction face for the adjacent lining

22

or forms a fixing face for the said lining.

Naturally an intermediate piece can be fixed to the wall

11

in order to constitute a friction face for the relevant lining

22

.

The disc

24

extends radially above the piston

20

in order to be connected, by a connection of the mortise and tenon type

4

, to the torsion damper

3

which is thicker at its external periphery in the vicinity of the rim

13

.

The torsion damper

3

has two coaxial parts

7

,

8

mounted so as to be able to move angularly with respect to each other counter to circumferentially acting elastic means

6

, here in the form of coil springs.

One of the parts, referred to as the input part

7

, has two guide rings

60

,

61

disposed on each side of the other part

8

in the form of a damper plate fixed at its internal periphery to the hub

5

.

The input part

7

is connected with respect to rotation to the drive disc

24

by the mortise and tenon type connection

4

allowing axial movement of the disc

24

.

Thus the input part

7

is disengageably connected to the transverse wall

11

forming part of the input element of the hydrokinetic coupling appliance, whilst the output part

8

is connected the output element

5

of the said appliance.

The damper

3

is located axially between the turbine wheel

101

and piston

20

.

The hub

5

has, in a single piece with a socket

50

, at its rear end, furthest away from the transverse wall

11

, a transversely oriented shield

51

thinner at its external periphery in order to form a countersink delimiting an axially oriented shoulder, not referenced, for centring the damper plate

8

and the annulus or the lugs

104

of the turbine wheel

101

. Rivets

105

connect the lugs

104

and damper plate

8

to the shield

51

and therefore to the hub. The damper plate

8

and lugs

104

are disposed side by side on the same side of the shield

51

, the lugs

104

being in contact with the shield

51

.

As a variant, the lugs or the annulus

104

and the damper plate

8

are disposed on each side of the shield

51

.

The lugs

104

, or as a variant the annulus

104

, and the damper plate

8

can then be fixed by welding.

The ring

21

is stepped in diameter and is fixed, in a known fashion, by welding to a sleeve

16

, directed towards the outside in the opposite direction to the piston

20

, which the transverse wall

11

has at its centre.

Thus the ring

21

has on the one hand a front portion

121

with a smaller diameter forming a centring device and fixed by welding to the sleeve

16

and on the other hand a rear portion

122

with a larger diameter in which there are produced the passages

221

for communication between the chamber

23

and the central blind hole

120

in the ring

21

. The ring

21

, through its stepped front portion

121

, is fitted in the sleeve

16

whilst being welded to the free end thereof by a welding bead.

The ring

21

is therefore centred by the transverse wall

11

, the shoulder formed by the change in diameter between the portions

121

,

122

being in abutment against the internal face of the wall

11

turned towards the piston

20

.

The hub

5

, directed axially towards the wall

11

, enters through its socket

50

into the blind hole

120

in the ring

21

for reduction of the axial bulk at the centre of the hydrokinetic coupling appliance between the reaction wheel

102

and the transverse wall

11

. The socket

50

extends axially as far as the passages

221

so as not to close them off and so as to increase its length to the maximum extent, which assists its sliding along the driven shaft

201

.

The hub

5

has an axially oriented annular rim

52

issuing in a single piece from the shield

51

and directed axially towards the wall

11

. This rim

52

therefore extends parallel to the hub

5

to the socket

50

. It extends radially beyond the socket

50

.

The rim

52

is shorter axially than the socket

50

and defines with the latter an annular recess

53

with a bottom closed off by the shield

51

.

The ring

21

enters the recess

53

through its rear end

123

belonging to the rear portion

122

. The pieces

21

and

5

therefore fit into each other.

A bearing

54

is interposed radially between the internal periphery of the rear portion

122

entering the groove

53

and the external periphery of the hub

5

in order to centre the hub

5

with respect to the ring

21

. Here the bearing is fixed to the ring

21

and constitutes a pilot bearing.

An axial stop

55

, here a needle bearing, acts between the transversely oriented bottom of the recess

53

and the rear face of the ring

21

. To do this, the shield

51

is hollowed out locally in order to receive the stop

55

.

A radial clearance exists between the external periphery of the rear portion

122

of the ring

21

and the internal periphery of the rim

52

, the ring being of reduced diameter at this point in order to be able to enter the groove

53

.

An axial clearance also exists between the free end of the rim

52

and the shoulder

124

formed by the change in diameter which the rear portion

122

has so that it can enter inside the annular groove

53

.

As a result the external periphery of the rim

52

has roughly the same diameter as the larger-diameter external periphery of the rear portion

122

, whilst being axially aligned with it.

The passages

221

affect the larger-diameter part of the portion

122

and are partly adjacent to the wall

11

.

The passages

221

are formed by drillings opening out in the hole

120

and extended outwards by radial grooves affecting the face of the rear portion

122

in contact with the wall

11

.

The piston

20

is here mounted so as to slide along a guide surface

59

formed by the external periphery of the rim

52

, provided with a recess (not referenced) in the vicinity of its free end for mounting a sealing joint

56

. This joint is a joint of the dynamic type since a relative rotation movement can occur between the piston

20

, fixed with respect to rotation to the wall

11

, and the hub

5

fixed to the turbine wheel

101

.

For its sliding along the guide surface

59

, the piston

20

has, at its internal periphery, an axially oriented ferrule

128

directed towards the shield

51

, which has a groove

57

for housing an axial stop

58

intended to cooperate with the rear face of the ferrule

128

in order to reduce friction. The countersink and the groove delimit another rim (not referenced) parallel to the rims

51

and to the socket

50

and being axially shorter than them. The hub

5

thus has a comb shape with annular teeth with different and increasing lengths.

As a variant, the ferrule

128

can carry the joint

56

by means of a recess.

When the lock-up clutch

2

is engaged the liquid (oil) cannot enter the chamber

23

since the linings

22

are clamped and the joint

56

prevents any entry. The turbine wheel

101

is then mechanically fixed to the impeller wheel

100

.

When the clutch is disengaged the liquid cannot flow towards the rim

51

because of the joint

56

.

Naturally, the rear portion

122

has a shoulder

125

at its internal periphery, formed by means of a change in diameter, for cooperating with the front face of the bearing

54

mounted in the recess

53

.

The external periphery of the socket

50

is in close centring contact with the internal periphery of the bearing

54

here fixed to the ring

21

different from that of a ring of the prior art through the machining of its rear portion.

The piston

20

is integral with respect to rotation with the transverse wall by means of tangential tongues

26

allowing axial movement of the piston along the rim

52

and its surface

59

.

The tangential tongues

26

, mounted in the chamber

23

, act between the wall

11

and piston

20

and are axially elastic and circumferentially acting. The tongues

26

are fixed to a drive piece

27

fixed to the wall

11

. This piece

27

, more clearly visible in

FIG. 24

, can be extended radially in order to offer a friction force to the lining

22

concerned.

Such a mode of assembly is described in the document FR-A-2 726 620.

Thus the tongues

26

, here mounted in a superimposed fashion, whose number depends on the application, are fixed by riveting at one of their ends to the drive piece

27

, itself fixed by riveting to the wall

11

, by means of rivets

228

, issuing by extrusion from the wall

11

. As a variant, other fixing members, such as normal rivets, screws, bolts, etc, can be used.

For this purpose, the drive piece has locally parts offset axially in the direction of the piston

20

for fixing the tongues. These parts are in the form of brackets

227

.

As a variant, the drive piece

27

can be fixed to the wall

11

by welding or bonding.

As a variant, the tongues

26

are fixed directly to protrusions issuing from the wall

11

and provided with extrusions for riveting the tongues

26

.

Naturally, the tongues

26

can be in a single piece with the drive piece.

For more information, reference should be made to the application FR-A-2 726 620.

The tongues

26

are fixed at the other end by means of rivets

28

to the piston

20

. As a variant, the rivets are replaced by other fixing members such as screws, bolts, etc.

This is achieved by means of holes

29

, here shouldered, which the wall

11

has coinciding axially with the rivets

28

.

The holes

29

are passage holes for a tool for crushing the heads of the rivets

28

, a counter-tool being placed on the other side of the piston

20

in order to effect the crimping as described below.

The passage hole

29

is stepped in diameter and has a smaller-diameter portion connected by a transverse shoulder to a larger-diameter portion.

This makes it possible to avoid the use of two-part fixing means, as described in the document FR-A-2 726 620.

Thus, as in this document, in

FIGS. 1

to

4

, the tongues

26

are first of all fixed, either directly to the wall

11

, or the assembly consisting of drive piece

27

and tongue

26

to the wall

11

.

Next, after fitting the disc

24

, equipped with the two friction linings

22

, between the wall

11

and the piston

20

, the tongues are fixed by riveting, using rivets

28

, to the piston

20

, by introducing a tool into each hole

29

in order to deform the head of the rivet

28

, a counter-tool acting on the other side of the piston

20

in order to form a support for the foot of the rivet

28

. Preferably a removable centring device is used, engaged in the sleeve

16

for centring the ferrule

128

of the piston

20

during the operation of fixing the tongues

26

to the piston

20

, and then the centring device is withdrawn and the ring

21

is fixed to the wall

11

.

Naturally, the tongues

26

are fixed to the piston by means of dished parts

290

projecting axially in the direction of the wall

11

, which the piston

20

has radially between its internal and external peripheries; the internal periphery of the piston

20

being offset axially in the opposite direction to the wall

11

with respect to its external periphery forming a friction face for the relevant lining

22

.

For this purpose, the piston

20

has an inclined portion between its external and internal peripheries. It is in this inclined portion that the dished parts

290

are formed.

The number of tongues

26

and therefore of protrusions

290

depends on the application.

Naturally, according to the invention, after the passage holes

29

are finally closed sealingly by means of fluidtight obturators consisting in

FIGS. 1

to

4

of fluidtight plugs

129

. Here the plugs

129

are shouldered and fixed by welding, or as a variant by screwing or bonding, or force fitting, to the wall

11

. The plugs

129

are for example metallic, being based on aluminium.

The plugs

129

are here stepped in diameter and shorter axially than the passage holes

29

. The plugs

129

have a larger-diameter head, introduced into the larger-diameter portion of the passage hole

20

, and a body, in the form of a rod, of smaller diameter, introduced into the smaller-diameter portion of the passage hole.

It will be noted that the shield

113

(FIG.

2

), fixed by the screws

112

to the wall

11

, has holes (not referenced) coinciding axially with the holes

29

for passage of the tool and plug

129

.

The head of the plug

129

and the larger-diameter portion of the passage hole are here turned towards the side opposite to the piston

20

, the body of the plug

129

being shorter axially than the smaller-diameter portion of the hole. Thus the plug is housed in the thickness of the wall

11

.

Naturally the structures can be reversed, as can be seen in FIG.

7

.

In this case the passage holes

229

are produced in the piston and finally closed by a shouldered plug

339

.

Thus the tongues are first of all fixed to the piston by means of the rivets

28

, then the tongues

26

or drive piece

27

, to which the tongues

26

are previously fixed, are fixed to the wall

11

, the piston

20

having holes

229

coinciding axially with, for example, fixing rivets

228

issuing by extrusion from the wall

11

. These holes enable a tool to pass to crush the rivets. Next the holes are plugged by means of a plug

339

.

The torsion damper

3

has, according to one characteristic, two guide rings

60

,

61

of symmetrical shape in order to reduce costs.

The two guide rings

60

,

61

are symmetrical (identical overall), disregarding the drive lugs

161

on the guide ring

61

, referred to as the first guide ring, closest to the piston

20

.

The other guide ring

60

, referred to as the second guide ring, is adjacent to the turbine wheel

101

.

The guide rings

60

,

61

are obtained with the same tooling. An additional operation is performed on the first guide ring

61

in order to obtain lugs

161

obtained by cropping and bending.

The lugs

161

are axially oriented and engaged in notches, not referenced, open radially towards the outside, and formed at the external periphery

240

of the disc

24

. This external periphery

240

is offset axially with respect to its plane main part of the disc

24

to which the friction linings

22

are fixed.

The axial offsetting of the external periphery is effected in the direction of the first guide ring

61

in order to reduce the axial length of the lugs

161

offset radially towards the inside with respect to the external periphery of the guide rings

60

,

61

.

These guide rings

60

,

61

are located at the external periphery of the turbine wheel

101

and wall

11

. The external periphery of the rings

60

,

61

extends in the vicinity of the rim

16

of the first half-shell

12

.

Thus the springs

6

can extend to a major extent radially above the piston

20

and come as close as possible to the rim

13

. The torsion damper

3

can allow large relative angular movements between its input part

7

and its output part

8

, fixed at its internal periphery to the shield

51

of the hub

5

, here by riveting, in the aforementioned manner.

The output part

8

, forming a damper plate, has a curved shape to match the shape of the turbine wheel

101

, so that the internal periphery of the damper plate

8

is offset axially in the direction of the shield

51

with respect to its external periphery extending parallel to the said internal periphery.

The external periphery of the damper plate

8

is formed by lugs

18

forming support lugs for the ends of the coil springs

6

. The springs

6

extend between two consecutive lugs and have a long circumferential length.

Opposite the lugs

18

, the guide rings

60

,

61

have, facing, dished parts

118

for supporting the circumferential ends of the springs

6

.

The guide rings

60

,

61

are connected together at their internal periphery by means of lugs

62

issuing from the rings and engaged between two lugs

18

. The lugs

62

extend at the external periphery of the damper plate

8

.

Between the dished parts

118

, the rings

60

,

61

have a curved shape and are contiguous at the level of their free external edges. These rings are fixed together by means of welding points effected at the dished parts

118

and lugs

62

, here contiguous.

The dished parts

118

are also contiguous (

FIG. 1

) and it is in this area that the fixing by welding is effected.

It will be noted that the lugs

161

, forming lugs for connecting in rotation, issue from apertures

163

produced in the curved parts of the guide rings

60

,

61

matching the shape of the coil springs

6

, shown diagrammatically in broken lines in FIG.

3

. The springs

6

are therefore held axially and radially by the guide rings

60

,

61

. These rings

60

,

61

, once assembled, externally envelop the springs

6

and have a circular contour

63

extending over more than 180° and extended at each of its ends by an inclined part

64

. The inclined parts are convergent and it is in these that the lugs

62

are produced.

Naturally the rings

60

,

61

are made from pressed plate.

The same applies to the wall

11

and piston

20

. The inclined parts

64

make it possible to progressively reduce the axial bulk. This profile enables the guide ring

60

to come as close as possible to the turbine wheel

101

.

Naturally,

FIGS. 5 and 6

, it is possible to profit from the inclined parts

64

in order to provide apertures

263

opposite these and to house, radially below the springs

6

, a second series of springs

160

, housed radially above the external periphery of the damper plate

8

and circumferentially between two lugs

18

. The springs

160

are end-of-travel springs, the lugs

18

coming to compress the said coil springs at the end of the relative angular movement between the parts

7

and

8

.

These inclined parts can be dished locally at

165

in order to form support areas for braces, for example small columns

262

connecting together the guide rings

60

,

61

and replacing the lugs

62

of FIG.

2

.

FIG. 7

shows the same configuration, the difference relating to the holes

229

, not shouldered, and plugs

339

affecting the piston

20

in the aforementioned manner for the fixings of the tongues. Thus the different figures can be combined together.

In

FIG. 8

the fixing of the lugs

62

of

FIG. 3

has been replaced by the fixing of the small columns

262

of

FIG. 5

, a single row of springs being provided.

In this case, the guide rings

60

,

61

are identical and therefore symmetrical, and the lugs

161

belong to a ring

362

fixed to the guide rings

60

,

61

by the small columns

262

, the ring

362

being tapered in shape and dished locally for supporting the small columns

262

.

It will be noted that, in this

FIG. 8

, the circular contour

63

has a greater circumferential extent and extends over almost 360° and is connected to transverse parts

164

to which the small columns are fixed.

In all the figures the guide rings

60

,

61

are contiguous at their top (at their external periphery) and are fixed locally by welding at this point, between the springs

6

in the dished parts

118

. These dished parts

118

are deformed locally at the centre in order to form two contiguous transverse areas

170

extending radially above the lugs

18

of the damper plate

8

.

The welding is carried out in these areas

170

, visible in one case in FIG.

6

.

At their internal periphery the guide washers are connected together by lugs

62

or braces

262

.

Naturally, the sleeve

16

can be extended and be closed at its end in order to form a centring device. In this case, the ring

21

can be force-fitted in the sleeve

16

, as described in the document FR-96 07 146. In this case the ring

21

can be made from synthetic material, so that the presence of the bearing

54

is not obligatory.

Naturally, the ring

22

can be fixed by crimping, deforming the sleeve

16

.

The presence of the torsion damper is not obligatory. The disc

24

can be made integral in rotation with lugs for the mortise and tenon connection

4

, the said lugs being secured to an annulus fixed to the turbine wheel. The disc

24

can be embedded in a friction lining

22

intended to be clamped between the piston

20

and wall

11

.

The presence of the bearing

54

is not obligatory. This is because a pilot bearing can be mounted in the blind hole

120

in order to centre the end of the driven shaft.

In all cases a pilot bearing is provided, such as the bearing

54

, in order to ensure good concentricity between the hub

5

and centring device

21

.

By virtue of the holes

229

,

29

it is possible to fix the tongues

26

locally, for example by welding or bonding, respectively to the piston

20

and to the wall

11

. It will be appreciated that the solution in

FIG. 7

is favourable since the hydraulic pressure prevailing in the main chamber presses the shouldered plug

339

against the piston

20

.

In addition, the wall

11

is intact.

In general terms, according to the invention, the elastic tongues

26

are fixed on the one hand, at one of their ends, by first means of fixing to one of the transverse wall

11

/piston 20 pieces, referred to as the first piece, and on the other hand, at their other end, by second means of fixing to the other one of the transverse wall

11

/piston 10 pieces, referred to as the second piece. The first piece (or first element) has passage holes

29

,

229

coinciding axially with the second fixing means. These passage holes

29

,

229

are closed off finally by sealing obturators

129

,

339

. The fixing means can consist of welding or bonding, extrusions or fixing members.

The invention profits from the circumferential offset between the ends of the tongues

26

. This offset allows the creation of the passage holes.

The plugs

29

,

229

are shouldered and shorter axially than the passage holes

29

,

229

. The heads of the plugs can be embedded in the transverse wall or slightly project beyond the piston (FIG.

7

).

The tongues

26

may not extend tangentially but be inclined. In all cases the tongues

26

are circumferentially acting since their ends are circumferentially offset.

The guide rings of the torsion damper can have any shape and may not be identical.

Naturally, the obuturator can have another shape and be housed in the thickness of the wall

11

or of the piston

20

.

In this case, the obuturator is in the form of a plate

439

and advantage is taken of the shape of the passage hole, which has, in the aforementioned manner, a smaller-diameter portion connected by a transverse shoulder to a larger-diameter portion. The passage hole is therefore stepped in diameter and the plate is housed in the larger-diameter portion constituting a countersink. For example, in

FIG. 9

, the passage hole can be seen at

539

and, at

540

, the shoulder formed by means of the change in diameter. The plate

439

is housed, in the larger-diameter portion, axially between the shoulder

540

and the rear face

541

of the piston

20

turned towards the turbine wheel

101

, opposite to the wall

11

. Naturally, it is possible, as a variant, to house the plate axially between the shoulder in the hole and the rear face of the wall turned opposite to the piston

20

.

The axial length of the larger-diameter portion is greater than the thickness of the plate.

The plate can be fixed by bonding, welding, crimping or deformation in the larger-diameter portion of the passage hole. The fixing is fluidtight.

Thus, in

FIG. 9

, the plate

439

is brought into contact with the shoulder

540

in the passage hole

539

and the edge of the hole

539

is locally crushed hot, using a punch, at the level of the rear face piston

20

. As a result there is a flow of material from the piston marked

531

. The plate

439

, in contact with the shoulder

540

, forming a seat with sealing, is thus axially immobilised after crimping between the flow of material

541

and the shoulder

540

.

In

FIG. 10

, a soldering wire forming a ring

542

is interposed between the plate

439

and the shoulder

540

. By heating, for example of an electrical nature, such as induction heating, the soldering ring

542

is caused to melt in order to obtain a sealed fixing. Naturally, the ring

542

can be replaced with glue. It is possible to effect the soldering at the front face, the plate turned in the opposite direction to the shoulder

540

.

In

FIG. 11

, the plate

439

′ is curved initially, being in contact at its external periphery with the shoulder

540

. Next, using a press tool, such as a punch, the plate

439

′ is crushed in the direction of the arrow F. At the end of this operation, the plate

439

′ is flat and is in contact with the contour of the larger-diameter portion of the hole

539

. A sealed fixing is obtained. Naturally, in

FIG. 4

, the plug

129

can be replaced with the plate

439

or

439

′.

The plate

439

or

439

′ can be replaced with a plug

639

whose head is housed in the thickness of the larger-diameter portion of the hole

29

in

FIG. 4

or of the hole

639

in the piston

20

, as can be seen in FIG.

12

.

The metallic plug

639

(FIG.

12

),

129

(

FIG. 4

) or

339

(

FIG. 7

) can be mounted by cooling the plug, for example to −40° in liquid nitrogen, and then introducing the plug into the associated passage hole.

The plug is therefore initially contracted, and then expands, thus jamming sealingly in the passage hole.

Naturally, the head of the plug can extend so as to project with respect to the larger-diameter portion of the passage hole as in FIG.

7

.

The passage hole can be not stepped, as visible at

739

in FIG.

13

. In this case, the obturator

639

consists of a pellet cold mounted in the hole in the aforementioned manner.

The plug

839

(

FIG. 14

) can have a head extending in axial projection with respect to the wall

11

or piston

200

.

The hole

939

is broadened at the head and has, at the other face, a portion with a larger diameter for housing a collar

831

and therefore delimited by a transverse shoulder

840

formed by means of the change in diameter of the hole.

The collar

841

is housed in the thickness of the wall

11

or piston

20

. The broadening of the collar of the hole

939

is tapered in shape for a good seal and the head of the plug curved in shape.

The collar

841

can be continuous (

FIGS. 23

,

24

). As a variant, it is divided into elastically deformable lugs radially by slots

842

, the plug advantageously being made of plastic material for mounting it by snapping into the passage hole.

Naturally, a sealing joint can be interposed between the passage hole and the plug in order to complete the seal. For example, in

FIG. 9

, a rubber joint such as an O-ring seal can be interposed between the shoulder

540

and the plate

439

. In

FIGS. 15 and 16

, it is the plastic plug

839

which is equipped with a sealing joint

850

. This joint is mounted in a recess

851

produced in the body of the plug

839

between its head and its collar

841

. The joint can have a square, rectangular, circular or other section. In

FIG. 16

, the joint

850

has an oblong shape.

The plug

839

has six elastically deformable lugs separated in pairs by slots

842

or

842

′, of different widths, four slots

842

and two slots

842

′ are provided. Naturally, this number depends on the application. The plug

839

, in a variant, has four lugs.

Naturally, the obturator can be in the form of a dish or tray

1039

engaged in a passage hole

1139

with a bevelled end

1040

.

The pan

1039

is forcibly engaged in the hole

1139

. This pan has an annular rim

1041

bearing on the relevant face of the wall

11

or of the relevant piston

20

. A joint can be housed in the cavity delimited by the bevel

1040

and a rim

1041

, in order to complete the seal.

As a variant, initially, the pan consists of a ring pressed into the passage hole in order to give it a pan shape.

In

FIG. 18

, the body of the pan

1039

is internally stepped in diameter with the formation of a shoulder

1042

serving as a support for the external periphery of a tapered Belleville washer

1043

. As a variant, several washers

1043

mounted in parallel are provided.

Initially, the Belleville washer

1043

is inclined in the direction of the rim

1041

. Using a tool, the Belleville washer

1043

is turned over in contact with the shoulder. After turning over, the Belleville washer occupies its position marked at

1044

and comes into contact with the raised part

1045

of the bottom of the pan.

Under the action of the Belleville washer, the pan

1039

increases in diameter. In

FIG. 19

, the pan

1039

, whose rim

1041

is initially inclined (

FIG. 20

) is deformed. At the end of the deformation the bottom of the pan

1039

flows. A protrusion

1046

is thus formed in contact with the bevelled end

1047

of the passage hole so that the pan is axially immobilised by its rim

1041

and its protrusion.

Naturally, the direction of mounting of the obturator, for example of the plug

29

of

FIG. 4

, can be reversed.

To do this,

FIGS. 21 and 22

, the larger-diameter portion of the passage hole opens out into a control chamber so that the plug

1239

has a head

1240

in contact with the liquid in the control chamber

23

.

According to one characteristic, this plug

1239

with reversed head forms a tool for the riveting in the tongues

26

. More precisely, the rivets

28

are crushed in contact with the heads

28

.

These rivets

28

each pass through a sleeve

1241

with shouldered head so that the tongue are initially inserted between the heads of the rivets and of the sleeve

1241

. Each sleeve

1241

passes through the piston

20

and, in accordance with one characteristic, elastic washers

1242

are mounted on the rivets

28

on the side of the piston turned towards the turbine wheel

101

, that is to say opposite to the chamber

23

.

The free ends of the plugs

1239

being in contact with a fixed part, the free ends of the rivets

28

are crushed by means of a riveting tool. During this operation, the heads of the rivets

28

come into contact with the heads

1240

forming anvils. The free ends of the rivets

28

flow when they are crushed so that the elastic washers

1242

are deformed in contact with the force of the piston

20

turned towards the turbine wheel

101

. The plugs

1239

therefore form counter-tools.

Afterwards the plugs

1239

are fixed by welding to the wall

11

, knowing that the passage holes

1339

are stepped in diameter, the larger-diameter portion of the hole

1339

opening out into the chamber

23

. There is therefore the formation of a shoulder

1340

by means of the change in diameter. The head

1240

of the plug

1239

is connected to the body, forming a rod, of the plug

1239

by a bevelled area

1243

coming into local contact with the edge of the shoulder

1340

. By heating of the bodies of the rivets, for example electrically, a sealed welding is effected, marked

1341

. During this operation, the rivets are pulled.

Naturally, the welding can be a welding of the friction type. It will be appreciated that the sleeves

1241

make the rivets

28

captive before they are riveted. Thus the tongues

26

are first of all fixed to the wall

11

, and then to the piston

20

in the aforementioned fashion. The elastic washers enable the clearances to be taken up.

In this figure, the damper plate

8

of the torsion damper

3

is fixed to the turbine wheel

101

. To do this, the metallic damper plate

8

has locally dished parts

80

fixed by clamping to the turbine wheel

101

at the same time as the blades of this wheel, as a variant, the fixing of the dished parts

80

, offset axially towards the wheel

101

, is effected by welding to the wheel

101

.

The inlet part

7

of the damper

3

is produced as in the document WO 94/07 058.

This inlet part consists of a guide ring having a portion for holding the springs

6

in the form of half-shell and support portions for the circumferential ends of the springs.

The damper plate

8

has at its external periphery a holding portion in the form of a half-shell offset axially and radially with respect to that of the guide washer.

This damper plate has clefts with a winding shape for supporting the ends of the springs. The disc

24

meshes with the ring

7

, by means of the connection

4

of the mortise and tenon type. For more information, reference should be made to the document WO 94/07 058.

In these

FIGS. 21 and 22

, the centring device of

FIG. 1

to

7

is omitted, the passages

221

being produced in the hub

5

with the interposing of a ring (not referenced) between the wall

11

and the hub

5

in order to reduce friction. The ring is fixed with respect to rotation to the hub

5

by means of studs engaged in blind holes in the hub

5

, as can be seen in FIG.

21

. The hub has an axially oriented annular guide surface

159

for the piston

20

.

Naturally, the disc

24

can have drive lugs

328

received between two consecutive springs.

The damper plate

8

has a peripheral annular portion

114

shaped as an axial recess open axially towards the wall

11

. Thus the elastic members

6

, carried by the disc

24

, or more precisely the lugs

328

provided with flats or fingers

134

for entering the springs. It is the disc

24

which carries the springs

6

. The drive plate is fixed to the wall

11

by extruded rivets issuing from the wall

11

. Lugs

142

,

148

are provided on the damper plate

8

in order to hold the springs.

The damper plate

8

is fixed to the hub

8

. The centring device

21

does not serve as a centring device for the hub

5

. The damper plate has dished parts

146

for supporting the springs

6

. For more information, reference should be made to the document FR 98/02 808 filed on Mar. 3, 1988.

The plug

1439

has a bevelled collar

841

, as in FIG.

14

. This collar is here continuous. The passage holes

1539

are produced in the piston

20

opposite rivets

228

. The holes

1539

are cylindrical, having no steps. The head of each plug projects with respect to the rear face of the piston

20

turned towards the damper plate

8

. The collar

841

projects axially with respect to the other face of the piston

20

turned towards the wall.

The plug is, for example, made from aluminium and is introduced into the hole

1539

by contraction as mentioned previously. As a variant, it is force-fitted in the hole

1539

, preferably being made from plastic, the collar

841

being continuous.

The invention is therefore of universal use, the damper plate

8

being able to mesh directly with the disc

24

as in the embodiment in

FIG. 5

in the aforementioned document FR/98 02 808.

Naturally, the structures can be reversed, the recess housing the sealing joint

850

being produced from the wall

11

or piston

20

, by means of the passage hole.

Number	Date	Country	Kind
97 08386	Jun 1997	FR
97 15600	Dec 1997	FR

Number	Name	Date
2253344	Nutt et al.	Aug 1941
2841262	Zeidler	Jul 1958
2858681	Smirl et al.	Nov 1958
4353444	Bionaz	Oct 1982
4750600	Adachi	Jun 1988
5613582	Jackel	Mar 1997
5826690	Maingaud et al.	Oct 1998
6065577	Arhab et al.	May 2000
6079530	Arhab	Jun 2000

Number	Date	Country
B18144	Nov 1955	DE
2711756	May 1995	FR
2738890	Mar 1997	FR
WO 9742433	Nov 1997	WO

Hydrokinetic coupling apparatus with lock-up clutch for motor vehicle

Information

Patent Number

Date Filed

Date Issued

Inventors

Original Assignees

Examiners

Agents

CPC

US Classifications

Field of Search

US

International Classifications

Abstract

Description

Claims

Priority Claims (2)

PCT Information

US Referenced Citations (9)

Foreign Referenced Citations (4)