KR100494959B1 - Hydrokinetic coupling apparatus, particularly for a motor vehicle - Google Patents

Abstract

The hydrodynamic coupling device has a generally transversely extending wall 2 with a guide ring 6 in the center thereof, and the piston 9 can be axially displaced along the guide ring 6. And a variable volume chamber 30 defined outwardly by the disk 10 together with the transverse wall 2, the friction seals 11, 111 between the piston 9 and the disk 10 and the disks. Respectively fixed between (0) and the transverse wall (2), each friction seal (11, 111) has at least one cooling groove (80, 180), one or more grooves (80, 180) According to the rotation direction of (10), it extends from the outer periphery to the inner periphery of each friction seal 11, 111 in the spiral body and is selectively distributed from one friction seal to the other friction seal. The present invention is useful for automobiles.

Description

HYDROKINETIC COUPLING APPARATUS, PARTICULARLY FOR A MOTOR VEHICLE}

The present invention relates to a hydrodynamic coupling device, in particular a vehicle hydrodynamic coupling device as described in WO-A-94 / 07058 and WO-A-93 / 13339.

The device described in this publication includes a wall that is generally transversely oriented and adapted to be rotationally coupled to the drive shaft and involves a guide ring fixed in the center on the wall.

The piston is hermetically mounted for axial movement along the guide ring and, together with the transverse wall and the guide ring, define a variable volume chamber enclosed by a disk and a friction liner, the friction liner respectively between the piston and the disk and It can be gripped between the disk and the transverse wall.

Each friction liner is secured to the disc and one of the elements consisting of each piston and the transverse wall, which liner can be gripped between the piston and the transverse wall.

As described in WO-A-93 / 13339, by controlling the pressure in the variable volume chamber, it is possible to control the differential pressure generated on the piston, taking into account the fact that two chambers exist on both sides of the piston. Can be.

This can control the sliding motion that can be achieved through the friction liner inserted between the disk and the assembly consisting of a transverse wall constituting the piston and the counter piston.

In order to improve the absorption of vibrations, the disks can be made to slide or slide in certain operating modes of the automobile engine. Thus, relative motion occurs between the disk and the assembly consisting of the piston and the transverse wall.

This sliding action heats the region of the disk, ie the outer periphery of the variable volume chamber. Thus, the oil in the hydrodynamic coupling device is heated in this area outside the variable volume chamber.

In order to reduce this heating effect, in WO-A-93 / 13339 each friction liner is arranged to have two annular grooves.

Each groove is connected through a plurality of radial passages, each having an inner and outer circumference of the disk.

The radial channel also joins the two grooves together.

Thus, during the period of controlled sliding motion, the pressure in the casing of the hydrodynamic coupling device is greater than the pressure in the variable volume chamber, and the fluid flows toward the interior of the variable volume chamber, ie from the outer periphery of the friction liner to the inner periphery. .

This is not entirely satisfactory because it is transmitted to a disk that is rotationally coupled to the turbine wheel and thus the torque transmitted to the driven shaft is reduced. Also, the inner flow of the fluid is not as fast as necessary.

1 is an axial cross-sectional view of a portion of a hydrodynamic coupling device according to the invention,

2 is a partial cross-sectional view cut in the direction of the arrow 2 of FIG.

3 is a cross-sectional view taken along the line 3-3 of FIG.

4 is a view of the back of the disk with a friction liner according to the present invention,

5 is a cross-sectional view taken along line 5-5 of FIG. 4,

Figure 6 is a view of the front of a disk with a friction liner according to the present invention.

The object of the present invention is to overcome these disadvantages in a simple and inexpensive way. Accordingly, it is an object of the present invention to increase the torque and fluid flow delivered while cooling the outer periphery of the variable volume chamber.

According to the invention, the coupling arrangement of the type described above is generally in the form of an arc of circle with the grooves offset relative to the center of the disc, extending from the outer periphery of the respective friction liner to the inner periphery and rotating the disc. Forming a portion of the spiral wound in a direction, the cooling groove being alternately spaced between one friction liner and the other friction liner, whereby the other groove of the friction liner begins where one groove of the friction liner ends. It is characteristic.

According to the present invention, when the lock-up clutch is engaged, it is impossible for the oil to escape due to the centrifugal force, so that a rapid fluid flow in the form of a centripetal shape is generated by increasing the torque transmitted to the disk and by the pumping effect. In addition, if the groove surface is reduced, fluid flow can be good.

Thus, the friction liner cools well and the groove exerts a viscous shear force to create the effect of driving the fluid.

Thus, because of the grooves, hot oil can be pumped past the liner to the outer periphery, which transfers the oil into a cooler variable volume chamber for cooling.

The resulting fluid flow in the grooves is proportional to the supply pressure and rotational speed, in particular to the different rotational speeds between the disk and the assembly consisting of the piston and the transverse wall.

Fluid mass flow towards the inside of the variable volume chamber increases as a function of sliding power. Therefore, the larger the slide motion, the larger the fluid flow rate.

Generally, the liner cools well. No point on the liner is far from the cooling groove or slot. In addition, because the grooves alternate between one friction liner and another friction liner, the number of outlets and inlets for the fluid increases, and the surface area of the friction liner becomes large.

Preferably, the width of the spiral groove according to the present invention increases as it is directed toward the outer periphery of the friction liner.

Thus, the viscous shearing force is exerted to increase the driving effect of the fluid.

The following description describes the invention with reference to the accompanying drawings.

As is known, the hydrodynamic coupling device described in WO-A-94 / 07058, referenced for more detailed description, is provided with a casing, torque converter and lockup clutch (1) filled with oil and installed in a co-sealed housing. ).

The casing constitutes a drive element and is suitable for rotationally coupling to a drive shaft, ie a crankshaft of an internal combustion engine when applied to a motor vehicle.

The casing in the annular form consists of two half shells facing each other, the outer periphery of which is sealed together by welding.

The first half shells 2, 3 can be rotationally coupled to the drive shaft and comprise a generally transversely oriented annular wall 2, the outer periphery of which being extended by a generally axially oriented cylindrical wall 3.

Like the recoil wheel of the converter, a second half shell, not shown for the sake of simplicity, is configured to define an impulse wheel having a blade fixed to the inner surface of the half shell. These blades face the blades of the turbine wheel 4 which are riveted or welded to a hub plate integral with the hub 5, which hub is rotationally coupled to the driven shaft, ie the input shaft of the gearbox when applied to a motor vehicle. The interior is splined to be. This shaft is grooved inward to define a channel that allows oil to reach the guide ring 6 which is axially fitted between the hub 5 and the transverse wall 2.

In particular, this ring 6 is provided with a central centering nose 7 protruding axially, the ring 6 being centered relative to the wall 2 by means of a seam 61, ie a welded joint, For this purpose the ring has an axially oriented central sleeve portion 60 that is bent outwardly, and a centering nose 7 penetrates into the sleeve portion. The ring 6 also has a collar portion 8 that is oriented horizontally. Thus, a shoulder is formed in the ring 6, which, after being fixed through the collar 8 and by welding, contacts the inner side of the wall 2 facing the hub 5.

The piston 9 is mounted to slide axially along the annular outer periphery of the collar 8 with grooves for mounting the annular sealing ring 29. The piston 9 has an axially oriented central sleeve portion that is bent towards the wall 2 for sliding along the collar 8. The piston 9 together with the ring 6, the wall 2 and the disk 10 holding the friction liners 11, 111 by adhesive or welding on both sides, respectively, are transported through a variable volume chamber ( 30, the ring 6 has holes not indicated for this purpose, which holes are conveyed through the channels in the driven shaft described above. In this embodiment, the hole is formed in the collar 8 and includes an inclined portion which is opened into a blind hole formed in the center in the ring 6. The disk 10 is fitted with an outer circumference of the piston 9 and has lugs 28 bent radially outwardly of the piston 9 at its outer circumference with an axially oriented portion, which lug Respectively, the inner periphery penetrates into the notch formed in the guide ring 12 and the radially oriented portion is coupled to the main portion of the disk 10. Thus, the disk 10 is rotationally coupled to the guide ring 12 so as to be able to move in the axial direction through the engagement 13 in the form of a tenon joint consisting of lugs and notches.

The notch is formed by the transverse portion 14 of the guide ring 12. This transverse portion 14 is extended by an axially oriented annular portion 15 and by an annular support portion 17 of the plate element 18 extending radially inwardly by the radial web 19. Acts to support the radially outward support of the coil spring 16 supported on the inner side, the radial web 19 having a radial plate portion of the hub 5, the inner periphery of which is represented by a lug (indicated by reference numeral). Not fixed) to the turbine wheel 4 with riveting.

In other embodiments, this fastening may be by welding. The web portion 19 has a set of holes (not shown) to allow oil to flow between the piston 9 and the wheel 4.

The plate element 18 has an engaging portion 20 for engaging the circumferential end of the spring 16. These portions 20 are formed of a serpentine junction bridge extending from the inner periphery to the outer periphery of the support portion 17 of the plate element 18. This part 17 is in the form of a half shell and is axially offset with respect to the parts 14, 15 of the guide ring 12 which is composed of a half shell. The guide ring 12 has an integral inner deformable portion 21 for joining with the end of the spring 16 in the region of its axial portion 15. The part 14 also has a lug 22 for contact with the end of the spring 16. For a more detailed description see WO-A-94 / 1047058, in particular FIGS. 24 to 28.

It will be appreciated that the components of the hydrodynamic coupling device, except for the sealing ring 29 and the liners 11, 111, are made of metal.

Thus, the lockup clutch 1 comprises a torsion damper 23 whose outer periphery of the first shell is located mainly between the turbine wheel 4 and the wall 2, with the input part 12 being a piston 9. And a guide ring 12 in the form of a half shell 14, 15, a coil spring 16 and an output portion, disposed radially outward of the liner 11, 111, the output portion also having The outer periphery consists of a plate element 18 in the form of a half shell.

The output portion 18 is rotationally coupled to the turbine wheel 4 and in particular the hub 5 of the turbine wheel, the input portion 12 being rotationally coupled to the disk 10 and projecting radially relative to the piston 9. . Thus, the input portion 12 is releasably coupled to the drive shaft via the disk 10 and the liners 11, 111, which, together with its liner, the piston 9 which constitutes a counter piston. ) And releasably gripping between wall (2). The disk 10 is elastically coupled to the hub 5 and the wheel 4.

In particular, the turbine wheel 4 is driven by the impulse wheel due to the flow of fluid contained in the sealed housing or casing, and in order to prevent slippage between the turbine wheel and the impulse wheel after starting the vehicle, the lockup clutch 1 ) Provides a direct solid coupling between the drive shaft and the driven shaft, by holding the disk 10 and the friction liner 11, 111 between the piston 9 and the counter piston 2. The driven shaft is driven directly by the shell 1.

In order to separate the clutch 1 (FIG. 1), pressure is transferred into the chamber 30 via a channel in the driven shaft, a blind hole in the ring 6 and a hole in the ring. The chamber 30 is sealed by a ring 29 supported by the collar 8.

In the engaged position of the clutch (liners 11 and 111 are gripped), the chamber 30 is depressurized. Thus, the chamber 30 has a disk 10 and liners 11 and 111 surrounding the outside thereof.

The piston 9 is rotationally coupled to the wall 2 of the first shell by tangential elastic tongues 40 spaced at regular intervals in the circumferential direction, in this embodiment there are four sets of tongues (Fig. 3). These tongues 40 allow the piston to move in the axial direction. In this embodiment, the tongue is attached to the transverse wall 2 via an inserted annular member 44, which member 44 is metal and is fixed to the wall 2 by rivets 45, for example, It is formed by injection and is integral with the wall. At its inner circumference, the annular member 44 comprises lugs 48 axially offset relative to the main part, by which the lug is fastened to the wall 2. In this embodiment, the tongue 40, which consists of two tongues lying together, is fixed at its end to the lug 48 by means of rivets 43. In other embodiments, the rivets may consist of screws or bolts.

In order to couple the other end of the tongue 40 to the piston 9, fastening means 41, 42, which can extend through the tongue 40 and the piston 9, are used, which fastening means 41, 42. ) Has two parts, the first part 41 attached to the tongue 40 on the side of the tongue opposite the piston 9, and the same side as the piston 9 for engaging with the first part 41. A second part 42 which is only necessary in the phase. Tongue 40 lies in a radially extending space, ie chamber 30, between the axis of the assembly and the friction liners 11, 111. The tongue extends axially between the wall 2 and the piston 9 in a region where the wall 2 protrudes axially away from the turbine wheel, so that between the piston 9 and the wall 2, the ring In the area | region of the collar part 8 of (6), a dimension becomes small in an axial direction.

In this case, the two-part fastening means 41, 42 are in the form of an upset bolt shank. The first part 41 comprises a shank with a coupling head. The shank passes through a hole in the piston 9 via a gap and includes a smooth first portion and a notched first portion. This portion 41 is fitted to the tongue 40 by force fitting or in other embodiments by rolling or adhesive. The coupling head of the shank 41 is mounted in the chamber 30.

The second part 42 consists of a seam ring comprising a large diameter base portion on the same side as the piston to prevent plastic flow into the through hole of the piston. Thus, the ring 42 is mounted outside the chamber 30.

As can be seen, the ring 42 will be compressed so that the ring will engage the notched portion of the shank. In other embodiments, rivets of the POP type may be used.

In another embodiment, the first portion may constitute a screw or nut secured to lug 40 by an adhesive, and the second portion is in the form of a screw or nut.

All devices described in French Patent Application No. 94 13205, filed November 4, 1994, may be considered.

In the embodiment of FIGS. 1-3, the joining means 50 is located in the chamber 30 to protect the tongue by limiting the deflection of the tongue 40. The joining means 50 is formed in the member 44, the tongue 40 being driven by the member 44 and fastened to the wall 2. In particular, the tangential tongue 40 in this embodiment extends circumferentially beyond the two-part fasteners 41, 42 which secure the tongue 40 to the piston 9.

The free end of each extension 47 is suitable for cooperating with a junction 46 facing towards the wall 2 (FIGS. 2 and 3). This junction 46 is part of the means 50 and is located locally parallel to the wall 2. The joint is press molded into lugs 48 axially offset relative to the major portion of annular member 44.

Therefore, the lug 48 has an end portion for fastening the rivet 43 and the joining portion 46.

Thus, from the main part of the member 44, the cross section is tongue 40; Ie generally formed by a bent portion (or claw) having an axially oriented portion surrounding the free end of the extension 47, which is bent by the transversely oriented portion 46. It consists of a joining means 50 which extends and is suitable for cooperating with the piston 9, ie the surface of the tongue 40 abutting towards the back of the tongue 40.

Thus, the junction 46 limits the movement of the piston 9 in the direction away from the transverse wall 2.

In this way, the contact of the hub 5 or the radial web 19 with the piston 9 is prevented, the relative displacement between the ring 6 and the piston 9 is limited, and the piston 9 is in every situation Maintain engagement with the seal 29. Thus, the chamber 30 is always sealed despite the expansion of the housing which occurs in a known manner during the rotation of the hydrodynamic coupling device.

In a variant embodiment, the joining means 50 can consist of individual rings attached by riveting or snap-fitting on the guide ring 6. This ring then protrudes with respect to the outer periphery of the collar and can cooperate with the inner periphery of the piston 9 to limit the displacement of the piston in a direction away from the wall 2.

Due to the joining means 50, the space present between the piston 9 and the liner 11 can be reduced when the lockup clutch is released or released.

This reduces the reaction time and allows for controlled sliding motion as described below.

As can be seen, the piston 9 defines two chambers, the variable volume chamber 30 and the main chamber located on the side of the back side of the piston 9 facing away from the wall 2. .

Thus, by varying the pressure of the variable volume chamber 30, it is possible to set the controlled sliding movement of the respective friction liners 11, 111 with respect to the piston 9 and with respect to the wall 2 consisting of the counter piston.

This controlled sliding motion allows the friction liners 11 and 111 to slide or slide, in particular, so that the disk 10 can slide or slip in certain operating modes of the engine, thereby improving vibration absorption.

Thus, relative motion occurs between the disk 10 with the liners 11 and 111 and the assembly consisting of the piston 9 and the transverse wall 2.

Thus, this sliding movement heats the friction liner, piston 9, disk 10 and wall 2, which heating takes place at the outer periphery of the chamber 30. Thus, the oil is heated to pass through the variable volume chamber 30 or close to the volume chamber.

The piston 9 and the wall 2 comprise a transverse portion at the outer periphery of the chamber 30 to provide a flat (horizontally oriented) friction surface for the friction liners 11, 111.

Thus, during the controlled sliding movement, the pressure in the major part of the housing of the hydrodynamic coupling device is higher than the pressure in the variable volume chamber 30.

In order to reduce the heating action, the present invention proposes to provide the friction liner with grooves 80, 180 in the form of a portion of the spiral extending from the outer periphery to the inner periphery of each of the friction liners 11, 111. , The winding direction of the helix is in the reverse direction of the rotation direction (Fig. 4) of the disk, that is, the rotation direction F of the engine, so that the scoop effect increases.

In this embodiment, four grooves or slots 80, 180 are provided for each friction liner 11, 111. These grooves are spaced at regular intervals in the circumferential direction, as shown in FIGS. 4 and 6. According to one feature of the invention, they are in the form of an arc off-centered with respect to the center of the disk 10, in the form of a helix, and in fact a part of the helix.

Of course, the length of the grooves can be larger or smaller.

Grooves, which are part of the helix, can increase the number of inlets and outlets that allow fluid to pass into the grooves, providing a large surface area for the liner.

In general, it is desirable to increase the number of grooves for rapid delivery of oil into the chamber 30. Of course, all of this depends on the application.

Preferably, the width of the grooves increases as they move toward the outer periphery of the friction liners 11 and 111. Preferably, the groove has a width greater than its depth. In order to facilitate the flow of the fluid (in this case oil) and to collect or drain the maximum amount of fluid, the cooling grooves are wide at the inner and outer periphery. It also prevents the liner from breaking.

The cooling grooves 80 and 180 alternate between one friction liner and the other friction liner, and when one cooling groove 80 ends at the inner periphery of the friction liner 11, the friction liner (at the outer periphery of the point) When the other cooling groove 80 of 11 starts and one cooling groove 180 ends at the inner circumference of the friction liner 111, the other cooling groove 180 of the friction liner 111 at the outer circumference of the point is finished. ) Starts.

Thus, the friction liner cools well because no point on the friction liner is remote from the cooling grooves 80, 180.

By means of the invention, during controlled sliding movements, the centripetal fluid flow is achieved by the pumping effect, and the fluid flows from the outer periphery of the disc 10 to the inner periphery of the disc, which acts on the back of the piston 9. This is because the pressure is generally greater than the pressure acting in the variable volume chamber.

Accordingly, the hot oil present beyond the friction liners 11 and 111 is transferred into the chamber 30 via the grooves 80 and 180 that pump the hot oil. Thereafter, the oil is cooled in the chamber 30.

The flow of fluid through the grooves is proportional to the speed, and due to the grooves pumping oil to the outer periphery of the chamber 30, the effect of driving the fluid by viscous shear forces occurs.

The mass flow rate of the fluid is proportional to the pressure difference and the speed, in particular to the speed difference between the disk 10 and the assembly consisting of the piston 9 and the transverse wall 2. This mass flow rate increases as a function of the sliding power.

Even with the cooling grooves 80, 180, good torque transfer from the wall 2 to the disk 10 is achieved. In short, good torque transfer from the wall 2 to the disk 10 depends entirely on the relative speed between the engine (and thus the wall 2) and the disk 10.

Fastening the friction liner on the disk 10 is advantageous because the lugs 28 make it easy to orient the groove with respect to the direction of rotation of the disk indicated by the arrow F in FIGS. 4 and 6.

Of course, the present invention is not limited by the embodiment described above. In particular, the rotational engagement of the piston 9 with the first half shells 2, 3 can be achieved by a piston 9 with a spline at its inner circumference, the spline having a ring 6 at its inner circumference. ), That is, for coupling with a compensation spline formed at the outer periphery of its collar portion.

In another embodiment, a rotary coupling form with a boss may be used as described in WO-A-94 / 07058, supra.

Of course, the rotary coupling is of the type described in WO-A-93 / 13339, ie a rotary coupling using a splined hub supported by a piston, with an internal spline disk supported by the wall 2 and fixed to the wall 2. It may be the same as. In this case, the spline disc provides a friction surface to the liner 111 such that the liner is gripped directly or indirectly, with a disc, plate, coating layer or the like interposed between the piston 9 and the transverse wall 2.

In another embodiment, the friction liners 11, 111 are fixed to the piston 9 or the wall 2, respectively, instead of being fixed to the disk 10 by adhesive or soldering, which are made by adhesive or soldering. Thus, each friction liner is secured to one of the elements consisting of a piston and a transverse wall, and a friction liner can be gripped between the piston and the transverse wall. The grooves 180, 80 may be formed on the surface of the friction liner 111, 11 facing the disk 10.

Of course, the structure of the rotary coupling 13 may be reversed, and the disk 10 has a mortise to which the tenons of the guide ring 12 are coupled.

In another embodiment, the disk 10 may be coupled by rotationally engaging the tenon and mortise to individual crown members supported on the turbine wheel 4. In this case, the disk 10 is firmly coupled to the turbine wheel 4.

Of course, the number of cooling grooves 80, 180 depends on the application, and in particular on the outer diameter of the friction liners 11, 111.

Claims (5)

A generally transversely oriented wall (2) having a guide ring (6) rotationally coupled to the drive shaft and sealingly mounted for axial movement along the guide ring (6), the ring ( 6) and a piston (9) forming a variable volume chamber (30) surrounded by a disk (10) together with the transverse wall (2), between the piston (9) and the disk (10), and the disk (10). And friction liners 11 and 111 respectively held between and the transverse wall 2, each friction liner 11 and 111 being in one element of the disk 10 and the piston 9, and the disk ( Fixed to one of the elements 10) and the transverse wall 2, wherein the liner is gripped between the disc 10 and the piston 9 and between the disc 10 and the transverse wall 2, with each friction In the fluid dynamic coupling device for automobiles in which the liners 11 and 111 are formed with at least one cooling groove 80 and 180, The cooling grooves 80, 180 are in the form of circular arcs offset with respect to the center of the disc 10, extending from the outer periphery of each friction liner 11, 111 to the inner periphery and in the direction of rotation of the disc 10. Defines a portion of the wound spiral, wherein the cooling grooves 80, 180 are spaced apart alternately between one friction liner 11, 111 and another friction liner 11, 111, and the friction liner 11 When one cooling groove 80 is terminated at the inner circumference of the), the other cooling groove 80 of the friction liner 11 starts at the outer circumference of the point, and one at the inner circumference of the friction liner 111 When the cooling groove (180) of the end, the fluid dynamic coupling device for a vehicle, characterized in that another cooling groove (180) of the friction liner (111) starts at the outer peripheral portion of the point. The method of claim 1, The cooling groove (80, 180) is a hydrodynamic coupling device for a vehicle, characterized in that the width is increased in the inner and outer periphery. The method of claim 1, Hydrodynamic coupling device for a vehicle, characterized in that the width of the cooling groove (80, 180) gradually increases from the inner peripheral portion to the outer peripheral portion of the friction liner. The method of claim 1, The friction liners 11, 111 are fixed to the disc 10, the discs having lugs 28 for elastically or rigidly rotationally coupling with the turbine wheel 4 of the hydrodynamic coupling device. A hydrodynamic coupling device for automobiles, characterized in that provided in the. The method of claim 4, wherein The lug 28 is bent and the axially oriented portion penetrates into the notch in the guide ring 12 of the hydrodynamic coupling device with the radially oriented portion coupled to the main portion of the disk 10. The hydrodynamic coupling device for an automobile, characterized in that the guide ring (12) is elastically coupled to the turbine wheel (4).

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