WO2006100406A1

WO2006100406A1 - Double-cover cross-flow damping device without indexing

Info

Publication number: WO2006100406A1
Application number: PCT/FR2006/050243
Authority: WO
Inventors: Antonin Groult
Original assignee: Peugeot Citroen Automobiles Sa
Priority date: 2005-03-22
Filing date: 2006-03-21
Publication date: 2006-09-28
Also published as: FR2883612A1; EP1869340A1; FR2883612B1

Abstract

The invention concerns a device for damping pressure oscillations exerted between two hydraulic fluid volumes (1, 2), said device comprising a separator (3) at two ends (31, 32) interposed between the two fluid volumes (1, 2) bored with two series of channels (40, 50), and bearing two valves (41, 52) elastically biased towards its respective ends (31, 32), the axial ends (31, 32) being hollowed out to define respective chambers (310, 320) bordered by annular seats of respective flaps (311, 312), whereon are pressed respectively the valves (41, 52). The invention is characterized in that the separator (3) comprises a cylindrical body (30) traversed by the axial channels (40, 50) and first and second directly mounted covers (312, 322) pressed on the cylindrical body (30) and defining the first and second chambers (310, 320).

Description

Cross-flow damping device with two lids without indexing

The present invention generally relates to the field of hydraulic rolling damping systems, of the type of those which are used in particular in suspensions of motor vehicles.

More specifically, the invention relates to a hydraulic rolling damping device for damping pressure oscillations exerted between first and second hydraulic fluid volumes, this device comprising a cylindrical separator having a main axis and carrying valve means non-return valves of first and second cross flow types and a first diameter peripheral sealing bearing separating the two fluid volumes, the valve means of the first type comprising a first series of axial channels passing through the separator and a first flexible blade shutter disposed in the first volume of fluid and resiliently biased toward a first axial end of the separator, and the second type valve means comprising a second series of axial channels passing through the separator and a second flexible blade shutter disposed in the second volume of fluid and elastically solicited to a second axial end of the separator, the first and second axial ends of the separator being hollowed to define respective first and second chambers bordered by respective first and second annular valve seats, which have a maximum diameter smaller than the first diameter, and on which the first and second shutters respectively rest, the axial channels of the first series connecting the first chamber to second radial interstices opening in the second volume of fluid between the second shutter and the bearing, the axial channels of the second series connecting the second chamber with first radial interstices opening in the first volume of fluid between the first shutter and the bearing.

Devices of this type are well known in the prior art, in particular for their use in suspensions of motor vehicles, and are for example illustrated by patent document EP 0 275 368.

Indeed, the suspension of a vehicle has the role of filtering and reducing shocks caused by the movement of the vehicle on unevenness of the road, to allow each wheel to always remain in contact with the ground, and to maintain a as constant as possible.

This function is performed by interposing between the box and the wheels an elastic element, usually a spring, which must dampen the oscillatory movement by a damper, the latter must simultaneously curb the oscillations of the body and those of the wheels, to avoid the bouncing of the wheels on the ground.

One of the most common technologies currently used to fulfill this damping function is to dissipate the energy of the oscillations by rolling oil between two volumes.

To do this, and as shown in the patent document mentioned above, the oil is constrained to be able to pass from one of these volumes to the other only through calibrated channels, closed by elastic metal strips or elastically deformable diaphragms which can only be displaced from their rest position by a minimum non-zero force, and which therefore allow an oil flow from one volume to another only if they are actually displaced from their position rest by a sufficient pressure difference between the two volumes.

The patent document cited above describes a device in which the channels of the first and second Each series opens into first and second annular chambers located at the two axial ends of the separator respectively, these first and second chambers being closed by the shutters.

These channels are of complex shapes, which make the cylindrical separator expensive and difficult to produce.

In this context, the present invention aims to provide a damping device to overcome the problems mentioned above.

To this end, the device of the invention, furthermore in accordance with the generic definition given in the preamble above, is essentially characterized in that the separator comprises a cylindrical body traversed by the axial channels and first and second fitted covers applied to the cylindrical body and respectively defining the first and second chambers.

Because of the presence of these covers, the shape of the cylindrical body becomes much simpler. It can be produced easily by sintering, in one piece. It does not have a thin wall, which are difficult to achieve.

In a possible embodiment of the invention, the channels of the first and second series of axial channels are arranged in a single circle around the main axis.

Advantageously, the axial channels of the first and second series may be distributed regularly and alternately in a circle around the main axis.

Preferably, the first and second covers may be identical.

For example, the device may further include a permanent leakage means, including a leakage passage pierced in one of the first and second annular seats and communicating the first and second volumes together permanently. Preferably, the cylindrical body may bear on first and second opposed axial faces respectively first and second series of bosses defining between them first and second series of radial channels, these radial channels connecting the second and first series of axial channels respectively to first and second radial interstices.

Advantageously, the bosses of the first and second series of bosses each comprise a countersink, the first and second series of axial channels opening respectively in the counterbores of the first and second series of bosses.

Preferably, the first and second covers each comprise a single bore respectively connecting the countersinks of the first and second sets of bosses to the first and second chambers.

For example, the first and second covers each comprise a plurality of openings disposed in a circle centered on the main axis, these openings connecting the countersinks of the first and second sets of boss respectively to the first and second chambers.

Advantageously, the body carries on each of its first and second axial faces a groove formed in the bosses of the first and second series of bosses and putting into communication the countersinks of the same series of bosses.

For example, the first and / or second cover may be disposed in any angular position around the main axis and does not require angular indexing during assembly.

Advantageously, the first shutter and / or the second shutter is of the recessed type.

Preferably, the first shutter and / or the second shutter is of type between supports.

Other features and advantages of the invention will emerge clearly from the description which is given below, as an indication and in no way with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a first embodiment of the device of the invention, a longitudinal part of the device being torn off to reveal the internal structure,

FIG. 2 is a perspective view of the cylindrical body of the device of FIG. 1, a longitudinal part of this body being torn off to reveal the internal structure,

FIG. 3 is a view in longitudinal section of the device of FIG. 1, that is to say in a plane which contains the main axis,

FIG. 4 is a cross-sectional view in the plane IV-IV of FIG. 3;

FIG. 5 is an axial view of an alternative embodiment of the device of the invention, the pin, the shutter and the stiffener being not shown,

FIG. 6 is a perspective view of another variant embodiment of the invention, the pin, the shutters and the stiffening disks being not shown,

FIG. 7 is a perspective view similar to FIG. 6, the first cover being removed,

FIG. 8 is a view in longitudinal section of the device of FIGS. 6 and 7, the pin, the shutters and the stiffening disks being represented, and

- Figure 9 is a view similar to Figure 3 for a second embodiment of the invention.

The invention relates to a damping device with hydraulic lamination for damping pressure oscillations exerted between first and second volumes 1, 2 of hydraulic fluid, shown in FIG. 3 respectively above and below the separator 3. , the latter being interposed between these two volumes.

This separator 3, which takes for example the shape of a cylinder centered on a main axis X, has first and second axial ends 31, 32 respectively facing the first and second volumes 1 and 2, and is traversed by first and second series of substantially axial channels, namely channels 40 and channels 50.

This separator 3 carries a peripheral seal bearing 6 having a diameter D and separating the two fluid volumes 1, 2, and check valves ^¬ return tared.

These check valves belong to a first or a second type, depending on whether they prohibit a fluid flow from the first volume 1 to the second volume 2, or a fluid flow from the second volume 2 to the first volume 1.

The valves of the first type comprise, in addition to the series of channels 40 which pass through the separator 3, a first shutter 41 with a flexible blade which is disposed in the first fluid volume 1 and which is resiliently biased towards the first axial end 31 of the separator 3 .

Similarly, the valves of the second type comprise, in addition to the series of channels 50 which pass through the separator 3, a second shutter 52 with a flexible blade which is disposed in the second fluid volume 2 and which is elastically biased towards the second axial end. 32 of the separator 3.

The first and second axial ends 31 and 32 of the separator 3 are hollowed to define first and second respective chambers 310 and 320, which are bordered by respective first and second valve annular seats 311 and 321 preferably taking the form of circular rings. .

These seats 311 and 321 have a maximum diameter D which is smaller than the diameter Dl of the separator, and provide support for the shutters 41 and 52.

The channels 40 of the first series of channels connect the first chamber 310 to the second interstices radial 22 which open in the second volume of fluid 2 between the second shutter 52 and the bearing 6.

The channels 50 of the second series of channels connect the second chamber 320 to first radial interstices 11 which open in the first volume of fluid 1 between the first shutter 41 and the bearing 6.

According to the invention, the separator 3 comprises a cylindrical body 30 traversed by the axial channels 40 and 50, and first and second reported covers 312 and 322.

The first attached lid 312 defines the first chamber 310, and is traversed by at least one bore, such as 313, 316 or 318, which connects this chamber 310 to the axial channels 40 of the corresponding series of channels.

Similarly, the second attached lid 322 defines the second chamber 320, and is traversed by at least one bore, such as 323, 316 or 318, which connects this chamber 320 to the axial channels 50 of the corresponding channel series.

In a preferred embodiment, the first and second covers 312 and 322 are identical, which helps to make the device particularly simple.

As shown in FIGS. 1 and 2, these first and second covers 312 and 322 each have the shape of a thin, flat disk with a diameter slightly smaller than the diameter D1 of the peripheral sealing bearing 6, centered on the main axis X. They are respectively plated on opposite first and second axial faces 33 and 34 of the cylindrical body 30.

The first and second covers 312 and 322 each carry a peripheral flange projecting from a side opposite the cylindrical body 30 and constituting respectively the first and second valve seats 311 and 321.

FIGS. 1 and 3 show that the shutters 41 and 52 are respectively applied to the seats of valve 311 and 321 by an elastic preload imparted to them by a stress-holding pin 7, this pin comprising a cylindrical hollow rod axially passing through the separator 3 and the shutters 41 and 52, and stops 71 and 72 disposed at the two opposite ends of the hollow rod which force the shutters 41 and 52 to approach one another.

Furthermore, the damping device of the invention comprises stiffening disks, such as 81 and 82, resiliently flexible and supported on the shutters 41 and 52, outside the chambers 310 and 320. These stiffening disks 81 and 82 have the role of increasing the stiffness of the shutters 41 and 52, without increasing the thickness.

More specifically, the disks 81 and 82 are respectively coaxial with the shutters 41 and 52 and are interposed between the shutters 41 and 52 and respectively the stops 71 and 72. These disks are traversed by the hollow rod of the pin 7. The stops 71 and 72 bear on a face turned towards the shutters 41 and 52 shoulders of diameter slightly greater than that of the hollow rod, these shoulders plating the stiffening disks 81 and 82 on the shutters 41 and 52. These shoulders are the only points of contact between the stops 71 and 72 and the stiffening disks 81 and 82. The shutters 41 and 52 are therefore stressed by a central portion, close to the hollow rod of the spindle 7. The stiffening disks 81 and 82 have diameters smaller than the shutter diameters 41 and 52.

Other flexible disks may be added between the disks 81 and 82 and the shutters 41 and 52. These disks then have intermediate diameters between the respective diameters of the disks and shutters which enclose them.

As also shown in FIGS. 1 and 3, one of the stops 71 of the spindle 7 can be constituted by a head thereof formed in disc, the other stop 72 may be constituted by a nut.

It can be seen in FIG. 4 that the channels of the first and second series of axial channels 40 and 50 are arranged in a single circle around the axis X.

The axial channels of the first and second series 40 and 50 are distributed regularly and alternately around the X axis, a channel 40 of the first series being framed by two channels 50 of the second series and vice versa. The first and second sets of axial channels typically comprise four channels each.

The channels of the first and second series of axial channels 40 and 50 are all identical, for example straight and substantially cylindrical.

The device may further comprise a permanent leakage means consisting of a leakage passage 330 of small size compared to the axial channels 40 and 50, pierced in one of the first and second annular seats 311 or 321, and communicating between them the first and second volumes 1 and 2 permanently. This passage 330 allows a low speed damping. It is represented in FIG.

As shown in FIG. 2, the cylindrical body 30 carries on its first and second opposite axial faces 33 and 34, respectively, first and second series of bosses 331 and 341. The bosses of the first series 331 define between them on the first axial face. 33 a first series of radial channels 332 respectively connecting the second series of axial channels 50 to the first radial interstices 11. Similarly, the bosses of the second series 341 define between them on the second axial face 34 a second series of radial channels 342 connecting respectively the first series of axial channels 40 to the second radial interstices 22.

Furthermore, the bosses of the first and second series of bosses 331 and 341 each comprise a countersink, respectively 333 and 343. The first and second series axial channels 40 and 50 respectively open into counters 333 and 343 of the first and second series of bosses 331 and 341.

More precisely, the bosses 331 of the first series are equal in number to the axial channels 40 of the first series. Each of these channels therefore opens at a first end in a counterbore 333 and at a second end opposite the first end in a radial channel 342 of the second series.

Similarly, the bosses 341 of the second series are equal in number to the axial channels 50 of the second series. Each of these channels therefore opens at a first end in a counterbore 343 and at a second end opposite the first end in a radial channel 332 of the first series.

In the first embodiment, shown in FIGS. 1 to 4, the first and second covers 312 and 322 each comprise a single bore 313 and 323 respectively connecting the countersinks 333 and 343 of the first and second boss series 331 and 341 to the first and second chambers 310 and 320.

As shown in FIGS. 1 and 3, these bores 313 and 323 have the shape of discs hollowed out in the center of the covers 312 and 322. The spindle 7 passes through these bores, the free part of these bores thus being reduced to an annular space surrounding the bores. pin 7.

It can be seen in FIG. 2 that the bosses of the first and second series of bosses 331 and 341 have the shape of sectors of rings regularly distributed on the first and second axial faces 33 and 34 of the support 30. The bosses of the same series join by their edges closest to the X axis to form a continuous ring surrounding the pin 7.

The countersinks 333 and 343 each comprise a first substantially circular portion in which an axial channel 40 or 50 opens, extended in the direction of the main axis X by a second portion in the sector. ring which extends partially in said continuous crown.

The annular free space of the bore 313 is superimposed on the continuous ring formed by the bosses of the first series 331, successively covering all the recessed portions in the ring sector of the countersinks 333 and the solid portions through which the bosses 331 meet. The first chamber 310 is thus placed in communication with the first series of channels 40, through the bore 313 and the countersinks 333.

Similarly, the annular free space of the bore 323 is superimposed on the continuous ring formed by the bosses of the second series 341, successively covering the recessed portions in the ring sector of the countersinks 343 and the solid portions through which the bosses 341 are together. The second chamber 320 is thus placed in communication with the second series of channels 50, through the bore 323 and the countersinks 343.

The first and second covers 312 and 322 have axial symmetry so as not to require angular indexing during assembly. They can be arranged in any angular position around the main axis X.

In this first embodiment, the first and second covers 312 and 322 are respectively plated on the bosses 331 and 341 of the first and second series. These bosses have planar free axial faces, all extending in the same plane perpendicular to the main axis X.

The first and second covers 312 and 322 are rigidly fixed to the body 30, by welding their radially outer edges on axial flanges 334 and 344 standing along the periphery of the first and second axial faces 33 and 34 of the body 30 and borne by radially outer edges of the bosses.

It will be noted in FIGS. 1 to 3 that the first and second shutters 41 and 52 rest at the same time on the first and second seats 311 and 321 and on cylindrical spacers 336 and 346 standing on the first and second axial faces 33 and 34, and surrounding the hollow rod of the spindle 7.

The free edges of the struts 336 and 346 on which the valves 41 and 52 rest are located in the same plane respectively as the free edges of the seats of the valves 311 and 321 as shown in FIG. 3. In an embodiment variant, not shown , the free edges of the struts 336 and 346 can be recessed inside the first and second chambers 310 and 320, the shutters 41 and 52 then being bulged towards the inside of the chambers 310 and 320 because of the stress exerted by the shoulders 71 and 72 on the respective central portions of the stiffening disks 81 and 82. By adjusting the axial position of the free edges 336 and 346, it is thus possible to adjust the stress of the shutters 41 and 52.

It will be noted that the diameter of the shoulders of the stops 71 and 72 is substantially the same as that of the struts 336 and 346, the stops 71 and 72 and the struts 336 and 346 thus pinching the shutters 41 and 52 and the stiffening disks 81 and 82.

FIG. 5 illustrates another variant of this first embodiment of the invention, the pin 7, the shutter 41 and the stiffening disk 81 not being represented in this figure. The body 30 is in accordance with the description given above, only the first and second covers having differences which will be explained below.

These first and second covers 312 and 322 are identical and each have in their center a circular orifice 315 in which the hollow rod of the spindle 7 is engaged.

The diameter of this orifice 315 corresponds to the diameter of the hollow rod of the spindle 7, so that the orifice 315 is closed by the spindle. The first and second covers 312 and 322 also include a plurality of oval apertures 316 evenly distributed in a circle around the aperture 315. The major axes of these oval apertures 316 are radial. These oval openings 316 connect the recessed portions in ring sector counters 333 and 343 and respectively the chambers 310 and 320.

These oval openings are sufficiently small compared to counters 333 and 343 and are sufficiently numerous that it is not necessary to index the first and second covers in rotation about the X axis relative to the body 30. Whatever the angular position of the covers around the axis X, there is always at least one oval opening 316 placing in communication each counterbore 333 and 343 with the chambers 310 and 320.

Figures 6 to 8 show an alternative embodiment of the invention. Only the differences with respect to the device of FIGS. 1 to 4 will be mentioned below.

The body 30 comprises on its first and second axial faces 33 and 34 two circular grooves 337 formed in the continuous rings formed by the bosses 331 and 341 around the spindle 7.

These circular grooves 337 surround the hollow rod of the spindle 7 and interchange the ring sector portions of the countersinks 333 and 343. The grooves 337 are separated from the spindle 7 by a portion of the thickness of the bosses as shown in FIG. shows Figure 7, so that no leakage can occur along pin 7.

The first and second covers 312 and 322 each comprise in their center a circular orifice 317, and one or more openings in circular arcs 318 surrounding the circular orifice 317. The openings in circular arcs 318 of each cover are in a circle which is superimposed on the circular groove 337 of the axial face of the body 30 on which the cover is applied. These openings in circular arcs 318 put in communication the countersinks 333 and 343 respectively with the chambers 310 and 320.

The spindle 7 passes through its hollow stem the circular orifices 317 of the first and second covers 312 and 322, these orifices being of diameter corresponding to that of the rod.

The first and second covers 312 and 322 may be disposed in any angular position around the main axis X with respect to the body 30, since the circular grooves 337 are continuous around the pin 7. They do not require angular indexing during assembly.

In the alternative embodiments of FIG. 5 and FIGS. 6 to 8, the first and second covers are not welded to the body 30, these covers being held by the constraint exerted by the shutters 41 and 52, and in a plane perpendicular to the main axis X, by the pin 7 passing through the circular orifices 317.

The operation of the device of the invention is as follows.

Inasmuch as the hydraulic fluids are very slightly compressible, the pressure prevailing at each instant in the second volume 2 is also the pressure that prevails in the second radial interstices 22, in the channels 40 of the first series, and in the first chamber 310.

Similarly, the pressure prevailing at each instant in the first volume 1 is also the pressure that prevails in the first radial interstices 11, in the channels 50 of the second series, and in the second chamber 320. Thus, when the pressure of the hydraulic fluid in the second volume 2 increases to a point where the force exerted by this pressure in the first chamber 310 exceeds the elastic force with which the first shutter 41 is pressed on the first valve seat 311, this shutter is displaced by the fluid present in the chamber 310 and thus allows the passage of a certain volume of this fluid from the second volume 2 to the first volume 1.

Similarly, when the pressure of the hydraulic fluid in the first volume 1 increases to a point where the force exerted by this pressure in the second chamber 320 exceeds the elastic force with which the second shutter 52 is pressed on the second seat Valve 321, this shutter is displaced by the fluid present in the chamber 320 and thus allows the passage of a certain volume of this fluid from the first volume 1 to the second volume 2.

As the displacement of the shutters 41 and 52 and the rolling of the fluid passing between these shutters and the corresponding valve seats require a non-zero amount of energy, the device described damps the pressure oscillations between the two fluid volumes 1 and 2.

Despite the simplicity of its structure, this device makes it possible to adjust independently of one another the pressures which lead respectively to the displacement of the shutters 41 and 52, this adjustment being able to be obtained, for example, by the choice of the diameter internal chambers 310 and 320, by the thickness of the shutters 41 and 52, by the number of holding retaining discs, and their respective diameters and thicknesses, and by the thickness of the spacers 336 and 346.

Although shutters and discs are a priori made of steel, it is also possible to use other materials, and / or different shades for the upper and lower valves.

It should be noted that the permanent leakage means can also be achieved by creating passages similar to the passage 330, in the bosses 331 and 341, these passages putting in communication the axial channels 40 and 50 with radial channels, respectively 332 and 342 , adjacent. The permanent leakage means can also be achieved by creating passages, similar to the passage 330, in the covers 41 and 52, these passages putting in communication the chambers 310 and 320 respectively with axial channels 50 and 40.

Moreover, it is easily understood that the damping device of the invention also works satisfactorily with elastic shutters of the recessed type, as in the embodiments of FIGS. 1 to 8, and with elastic shutters of the type between supports. , as in the second embodiment of the invention, shown in Figure 9, which will be described below.

Only the differences between the device of FIG. 9 and those of FIGS. 1 to 8 will be specified, the identical or similar elements keeping the same references.

In this second embodiment, the first and second shutters 41 and 52 each have the shape of a ring of inside diameter significantly greater than the diameter of the hollow rod of the spindle 7.

These shutters are supported by respective radially outer edges 411 and 521 on the valve seats 311 and 321. They are also supported by radially inner edges 412 and 522 respectively on annular supports 93.

These annular supports 93 are rigid washers threaded onto the hollow rod of the spindle 7, these washers having inner diameters corresponding to that of the stem. They have an outer diameter slightly greater than the inner diameter of the shutters 41 and 52 and less than the outer diameter of these shutters.

These supports 93 rest on the first and second covers 312 and 322 by means of annular centering wedges 94, threaded onto the rod of the spindle 7 and having inner diameters corresponding to that of the rod. The radially inner edges 412 and 522 of the shutters rest on axial faces of the supports 93 turned towards the body 30.

The centering wedges 94 have an outside diameter close to but slightly smaller than the inner diameter of the shutters 41 and 52, such that these shutters are held in position in a plane perpendicular to the main axis by the centering wedges 94.

Each shutter between support 41 and 52 can let the hydraulic fluid pass in the two opposite directions, that is to say from the first volume 1 to the second volume 2 and vice versa.

When the pressure of the hydraulic fluid in the first chamber 310 exceeds the elastic force with which the first shutter 41 is pressed on the first valve seat 311, the radially outer edge 411 of the shutter lifts and lets the fluid pass from the second volume 2 to the first volume 1. Conversely, when the pressure in the first volume 1 is greater than the elastic force with which the first shutter 41 is pressed on the annular support 93, the radially inner edge 412 is raised and let the fluid from the first volume 1 to the second volume 2.

The lifting of the outer edge 411 is limited by an annular limiter 91, of rigidity much greater than that of the first shutter 41. This limiter is also threaded onto the rod of the pin 7 and has a diameter interior corresponding to that of the stem. It is plated on one face of the abutment 71 facing the body 30. Its outer diameter is close to the outer diameter of the shutter 41.

An annular control shim 92 is interposed between the annular limiter 91 and the support 93. As before, this control shim 92 is threaded onto the rod of the spindle 7 and has an inner diameter corresponding to that of the rod. It has an outer diameter less than or equal to the outer diameter of the centering wedge 94.

The second shutter 52 is also provided with an annular limiter 91 and a control shim 92. It functions in the same way as the first shutter 41. As shown in FIG. 5, the radially inner edges 411 and 521 of the shutters 41 and 52 are, at rest, axially offset towards the body 30 relative to the radially outer edges 412 and 522. The shutters 41 and 52 are thus constrained to bear on both the valve seats 311 and 321 and on the annular supports. 93.

It will be noted that the operating characteristics of the damping device thus constituted can be modified by varying many parameters, such as: the inside and outside diameters of the shutters, the outside diameter of the annular limiter 91, the thickness of the wedge of 92 control, the outer diameter and the thickness of the centering wedge 94 the axial offset between the inner and outer edges of the shutters, that is to say the prestressing of these shutters.

In an alternative embodiment, the separator 3 may be equipped with a first axial side of a cover supporting a shutter between supports, the other axial side being without a shutter and carrying a cover without drilling to close the series of channels that is not associated with the shutter. A single shutter is sufficient in this case since it lets the fluid flow in both directions.

In another alternative embodiment, the separator 3 may be equipped with a shutter recessed on one axial side and a shutter between supports on the other axial side, which allows to modulate the operating characteristics of the separator.

Finally, it is possible to focus on one another the cross flows between the volume 1 and the volume 2 by increasing the total area of the channels of the corresponding series of channels 40 or 50 with respect to the total area of the channels of the other series 50 or 40.

Both embodiments of the invention can be applied for the realization of hydropneumatic dampers or piston dampers for motor vehicles. In the latter case, the cylindrical separator 3 is used as the guide element of the piston. The separator is then secured to the piston and slides in the body of the damper. In the case of a hydropneumatic suspension, the separator is fixed and integral with the body of the damper.

It is therefore clear that the damping device of the invention has a simple and regular structure. Both lids reported are identical.

The body 30 of the separator 3 can be easily made by sintering. It does not include internal concavity or thin walls.

These features make the device simpler and less expensive to manufacture and simplify the management of spare parts.

It is also possible to include dedicated means for low speed damping.

The body 30 may carry bosses of different shapes from those illustrated in FIGS. 1 to 9 without departing from the scope of the invention. Thus, these bosses may not extend to the radially outer edge of the body 30.

Similarly, the axial channels may have sections perpendicular to the axis X, non-circular. These sections may for example be in the ring sector centered on the X axis. The sections of the various axial channels then all fit into a ring centered on the X axis.

The counterbores may also have different shapes from those of FIGS. 1 to 9. They may, for example, fit through their first part the profile of the axial channels, this first part thus constituting a simple extension of these channels.

The openings in circular arcs 318 may also have various shapes. They can be two, three, four or even more. They may be mutually spaced enough along the circle formed around the X axis, as in Figure 10, or on the contrary very close, only thin partitions separating them. The radial width of the openings 318 can also vary widely.

Claims

A hydraulically rolling damping device for damping pressure oscillations exerted between first and second volumes (1, 2) of hydraulic fluid, said device comprising a cylindrical separator (3) having a main axis

(X) and carrying first and second cross-flow calibrated check valve means and a first diameter peripheral seal bearing (6)

(D1) separating the two fluid volumes (1, 2), the valve means of the first type comprising a first series of axial channels (40) passing through the separator (3) and a first shutter (41) with a flexible blade disposed in the first volume of fluid (1) and elastically biased towards a first axial end (31) of the separator (3), and the valve means of the second type comprising a second series of axial channels (50) passing through the separator (3) and a second shutter (52) with a flexible blade disposed in the second volume of fluid

(2) and elastically biased toward a second axial end (32) of the separator (3), the first and second axial ends (31, 32) of the separator (3) are hollowed to define respective first and second chambers (310, 320 ) bordered by respective first and second annular valve seats (311, 321), which have a maximum diameter (D) smaller than the first diameter (D1), and on which the first and second shutters (41, 52) rest respectively; ), the axial channels (40) of the first series connecting the first chamber (310) to second radial interstices (22) opening in the second volume of fluid (2) between the second shutter (52) and the bearing ( 6), the axial channels (50) of the second series connecting the second chamber (320) to first radial interstices (11) opening in the first volume of fluid (1) between the first shutter (41) and the bearing (6), the separator (3) comprises a cylindrical body (30) traversed by the axial channels (40, 50) and first and second attached covers (312, 322) applied to the cylindrical body (30) and defining respectively the first and second chambers ( 310, 320), said device being characterized in that the cylindrical body (30) bears on opposite first and second axial faces (33, 34) respectively first and second series of bosses (331, 341) defining between them first and second sets of radial channels (332, 342), said radial channels connecting the second and first sets of axial channels (50, 40) respectively to the first and second radial gaps (11, 22) and the bosses of the first and second sets of bosses (331, 341) each comprise a counterbore (333, 343), the first and second series of axial channels (40, 50) emerging respectively in the countersinks (333, 343) of the first and second series of bosses (331, 341). ).

2. damping device according to claim 1, characterized in that the channels of the first and second series of axial channels (40, 50) are arranged in a single circle around the main axis

(X) •

3. damping device according to claim 2, characterized in that the axial channels of the first and second series (40, 50) are distributed regularly and alternately in a circle around the main axis (X).

4. damping device according to any one of claims 1 to 3, characterized in that the first and second covers (312, 322) are identical.

5. damping device according to any one of claims 1 to 4, characterized in that it further comprises a permanent leakage means, comprising a leakage passage (330) drilled in one of the first and second seats annular (311, 321) and making communicating between them the first and second volumes (1, 2) permanently.

6. damping device according to any one of the preceding claims, characterized in that the first and second covers (312, 322) each comprise a single bore (313, 323) respectively connecting the countersinks (333, 343) of the first and second boss series (331, 341) at the first and second chambers (310, 320).

Damping device according to one of the preceding claims, characterized in that the first and second covers (312, 322) each comprise a plurality of openings (316) arranged in a circle centered on the main axis ( X), said openings (316) connecting the countersinks (333, 343) of the first and second boss series (331, 341) respectively to the first and second chambers (310, 320).

8. damping device according to any one of the preceding claims, characterized in that the body (30) carries on each of its first and second axial faces (33, 34) a groove (337) formed in the bosses of the first and second series of bosses (331, 341) and putting in communication the countersinks (333, 343) of the same series of bosses.

9. damping device according to any one of the preceding claims, characterized in that the first and / or the second cover (312, 322) can be arranged in any angular position around the main axis (X ) and does not require angular indexing during assembly.

10. Damping device according to any one of claims 1 to 9, characterized in that the first shutter (41) and / or the second shutter

(52) is of the recessed type.

Damping device according to one of Claims 1 to 9, characterized in that that the first shutter (41) and / or the second shutter (52) is of type between supports.