FR2790290A1 - DAMPING DEVICE OF A HYDRAULIC MANEUVERING SYSTEM OF A RELEASE COUPLING - Google Patents

Abstract

The invention relates to a damping device, intended in particular to dampen pressure oscillations and / or pressure pulsations in a hydraulic operating system, comprising at least one master cylinder, a slave cylinder and a pressure line which connects, in which the damping device (la) which is connected to a component of the operating system and can be stressed by a pressure fluid comprises a casing (2) including at least one element. In this device, the volume of the casing (2) can be increased in opposition to the effect of an energy accumulator (12). In more detail, a closure body (13), which is mounted in a leaktight manner in the internal space of the casing (2) and rests on an elastic element (12), is biased directly or indirectly by a fluid under pressure, in a damping device (la) by means of which can be damped pressure oscillations of a hydraulic operating system with master cylinder, controlled by pedal, and slave cylinder. The invention proposes several aspects as to its realization.

Description

The present invention relates to a damping device

  pressure oscillations in hydraulic systems. Such damping devices are for example used for a hydraulic operation of a clutch release in motor vehicles, simply called vehicles in the following. The operating system comprises a master cylinder which can be activated by a coupling pedal which can be operated by the driver and is connected by a pressure line to a slave cylinder arranged on the clutch release. The pressure line contains a damping member, the casing of which comprises a membrane stressed by a fluid under

pressure.

  In addition, the damping device integrated into the operating system or connected to the latter can be provided with a casing which includes a free floating membrane as well as a retaining element which constitutes a stroke limitation for the membrane when pressure oscillations or pressure pulses increase to the point of becoming inadmissible. Hydraulic systems which are mounted in vehicles to maneuver a clutch coupling which can also be advantageously of the automatic backlash type require damping devices by means of which pressure oscillations which can be transmitted are damped from the combustion engine to the operating system. The structure of the operating system comprises a slave cylinder which acts on a release bearing for the clutch release clutch and which is connected by a pressure line to a master cylinder, with which a coupling pedal actuated by the driver cooperates directly. , or which is, for example, maneuvered automatically using an electric motor and preferably under the control of a control unit. The damping device can then be incorporated into a component of the operating system or be connected to one of these components. The invention relates to the structure of the damping device, the housing of which is provided with an internal space or hollow space in which a body is arranged which can slide, in leaktight manner, when oscillations

pressure appear.

  As mentioned previously, hydraulic systems are used inter alia to maneuver a clutch coupling in a vehicle. The operating systems structure comprises a master cylinder which is preferably functionally connected to a pedal to be operated by the driver. A pressure line connects the master cylinder to the slave cylinder which intervenes indirectly via a clutch release bearing on the clutch clutch connected to the combustion engine. Due to the mode of operation and the structure of the combustion engine, which includes several oscillating engine mechanisms, the crankshaft of the combustion engine which is connected to the clutch release coupling is subjected to constant variations between an acceleration phase and a slowdown phase. Due to the ignition pressure or the force of the gases in the combustion space of the combustion engine, which are transmitted from the piston by the engine mechanism to the crankshaft, the distances between the faces of the crankshaft vary at high frequency and cause axial oscillations. Since the clutch coupling is coupled directly to the crankshaft, the axial oscillations are transmitted to the hydraulic operating system and cause pressure pulses which are transmitted by the master cylinder to the pedal operated by the driver and lead to an unpleasant tingling, which reduces comfort. Since the oscillation damping masses are low in a hydraulic actuation system, the transmission of the oscillations is more intense than

in a mechanical system.

  French patent FR-2 762 662 Ai discloses a damping device of the type mentioned in the introduction which is preferably integrated into the pressure line of the hydraulic operating system. The known damping device comprises a hollow space casing into which a recess for receiving an elastically deformable body is connected, being offset with respect to the direction of flow. The plastic body is sealed in the damping device and is provided with a stop on the side opposite the internal space. The elastic material of the known damping device does not allow any defined damping characteristic, which makes its practical implementation and its specific adaptation to the vehicle difficult. The damping material must also be selected taking into account a resistance to the pressure fluid used in the hydraulic operating system, which is a

brake or coupling.

  The combustion process of a combustion engine also causes axial oscillations which differ markedly depending on the number of cylinders of the combustion engine and their combustion process. The axial oscillations are transmitted by the crankshaft to the clutch release bearing and to the slave cylinder via the friction coupling or coupling springs. From there, the axial oscillations propagate throughout the hydraulic clutch system and cause pressure pulsations which can cause an unpleasant tingling in the coupling pedal which reduces comfort. Since friction is low in a hydraulic declutching system, the transmission of pressure pulses is more intense than in

  mechanical release systems.

  To avoid pressure pulsations, it is known to use throttles or plugs in the hydraulic line in order to increase the resistance to flow so that a resistance

  sufficient is opposed to the axial oscillations.

  However, this provision has a very

  unfavorable on the performance of the hydraulic system.

  This drawback results from a displacement by volume which is caused by the axial oscillation of the crankshaft and which causes the flow speed in the pressurized lines to be significantly lower than the flow speed which appears when the hydraulic clutch system is put in

taken or released.

  The German document DE-A-29 38 799 discloses a hydraulic damping device which is connected to a pipe for pressurized fluid connected between the master cylinder and the slave cylinder. The structure comprises a piston which is slidably mounted in the housing of the damping device and which is stressed by the pressurized fluid, on the one hand, and rests on a force spring, on the other hand. This known damping device corresponds to an expansion element which is introduced into the pressure line and which receives, by sliding of the piston, the volume displaced by the oscillations or the pressure pulses and is supposed to restore it during a fall. pressure. This provision is made to prevent oscillation from reaching the master cylinder or the coupling pedal. Such an arrangement not only exerts only a poor damping effect, but also reduces the efficiency of the hydraulic declutching system because the latter which acts as a damping member with elastic effect also receives, during the process of coupling, volumes of pressure fluid that correspond to

  the respective increase in pressure.

  British patent GB-A 22 46 819 also represents a damping device for a hydraulic operation of clutch release couplings. This known damping device comprises two freely oscillating membranes integrated in a casing in order to compensate for pressure oscillations which appear. To fix its position, each membrane is attached to the housing by a cover. The jar-shaped cover completely encloses the membrane here. A peripheral edge of the cover is folded inside on the end side and is applied to the rear of a projection of the housing. The metal damping device is of high self-weight and includes a clip

expensive membrane.

  In hydraulic systems for operating the clutch coupling, there is often also the problem that the oscillations caused by the combustion process of a combustion engine are transmitted via the crankshaft in the form of axial oscillations. the coupling pressure plate and are transmitted to the clutch release mechanism and to the master cylinder connected to it. These oscillations cause vibrations of the coupling pedal, perceptible by the driver when the latter actuates the pedal to disengage the clutch release, or intervene unfavorably on an actuator of the master cylinder when an actuator is used instead of the coupling pedal. The axial oscillations are then transmitted, in the form of pressure pulses, from the slave cylinder to the master cylinder by the column of fluid in the pressure line and, in this way, to the coupling pedal or to the actuator. In order to compensate for these annoying pressure pulsations, it is known to partially produce the pressure pipe in the form of a flexible tube. The elastic properties of the flexible tube are supposed to eliminate or absorb pressure pulses which appear in the hydraulic system between the master cylinder and the slave cylinder. This known arrangement is detrimental to the efficiency of the hydraulic operating system because this damping member also receives, during the coupling process and the pressure increase associated therewith, corresponding volumes of the fluid.

under pressure.

  The British patent GB-A-22 46 819 shows another damping device for a system of

  hydraulic operation of a clutch coupling.

  This known device comprises two membranes arranged in opposition in order to compensate for pressure oscillations which appear. To fix its position, each membrane is attached to the housing by a pot-shaped cover which encloses the membrane. A peripheral edge of the cover is folded inside on the end side and is applied to the rear of an appendage of the housing. The cover which surrounds the membrane is here arranged at a relatively large axial distance from the membrane. This cover therefore represents neither protection in the event of overload, nor a limit switch for the membrane, and the result is a large amplitude of oscillations for a strong pressure pulse. US Patent 5,070,983 shows a damping device of the type mentioned in the introduction. The membrane of this device is supported on the front side of a casing and is surrounded by a pot-shaped retaining element which surrounds by an edge a cylindrical end region of the casing and is applied to the rear of

  the appendix of the housing on the end side.

  The retaining element is arranged at an axial distance from the membrane and has, in the region of the middle of the membrane, a projecting appendage which constitutes a limit stop or limit for the membrane. The structure of this known device comprises, with the exception of the membrane, components to be manufactured by machining with chip removal or in the form of cast parts, with high self-weight. Due to the dead weight, the known damping device requires an appropriate secure fastening, which therefore raises assembly difficulties and costs.

correspondents.

  In order to improve the comfort of use of the hydraulic operating system, this can include a damping device, in the casing of which is mounted a valve support with two valve elements which are arranged in an offset manner and

  associated with different flow directions.

  Each elastically stressed valve element forms

  with the valve support a sealing seat.

  To avoid these pressure pulsations or pressure oscillations, it is known to use pressure accumulators. An attempt has also been made to increase the resistance to flow by lengthening the hydraulic lines or by incorporating a hydraulic throttle or plug, so as to

  to provide sufficient resistance to the oscillations.

  The axial displacement of the crankshaft causes a displacement of volume which triggers in the pressure lines of the hydraulic system a flow rate substantially lower than that which appears during engagement or disengagement of the operating system. It is therefore mainly on the efficiency of the operating system that this arrangement which increases the resistance to flow

has an adverse influence.

  German patent DE 44 28 074 A1 discloses a valve arrangement on the valve support from which two valve elements of spherical configuration are supported. The valve seats associated with the valve elements are arranged on front faces of the valve support opposite one another. In housing halves between which the valve support is mounted, two recesses are provided to receive, each for a valve element, a compression spring which is supported between the latter and the housing. In its closed position, the valve element in the form of a sphere rests by linear contact on the valve seat of conical structure. A flow of pressurized fluid can occur when the pressure exerted on one of the valve elements by the pressurized fluid is greater than the back pressure exerted by the compression spring. In the open position, the valve element is bypassed by the flow of pressurized fluid, the flow may adversely be turbulent, depending on the configuration of the valve seat and the valve element mounted downstream. This can lead to an unstable position of the valve element, and generate a noise which results from an opening beat of the valve element. It is the object of the present invention to remedy the drawbacks of the state of the art by producing a robust damping device, of economical manufacture, with defined damping characteristics. It is another object of the invention to produce, taking into account the drawbacks of the state of the art, a damping device which has, in addition to a high damping characteristic, a number of components reduced. The coupling device must also be optimized in terms of its weight. It is yet another object of the invention to provide a damping device which has both a high damping property and a safety against unacceptable pressure pulsations. It is another object of the present invention to remedy the drawbacks of the state of the art by producing a damping device such that its valve element is in a stable state in the

  open position and avoids noise development.

  According to a first aspect the invention achieves these goals by providing a damping device, intended in particular to dampen pressure oscillations and / or pressure pulsations in a hydraulic operating system, comprising at least one master cylinder, one cylinder servo and a pressure line which connects them, in which the damping device which is connected to a component of the operating system and can be stressed by a pressure fluid comprises a casing including at least one element, characterized in that the casing volume can be increased in opposition

  to the effect of an energy accumulator.

  This casing can be a separate casing reserved for the damping device or can be the casing of another component, for example the master cylinder or the slave cylinder. The increase in volume is carried out advantageously by means of a component arranged in a sealed manner in the housing, for example a punch which is movable in a recess provided for this purpose in the housing in opposition to the effect of an energy accumulator, for example a spring, a

  element of elastic plastic material or the like.

  It may also be advantageous to move relative to the other two elements of the housing. The force constant, for example the elastic constant of one or more disc springs and / or helical springs of the energy accumulator can then be adapted, linearly or not, for example gradually or degressively, d in such a way that the force exerted by the energy accumulator on the movable component in a sealed manner, which produces the increase in volume, does not depend linearly on its path. In the intended pressure zone of the damping device, the rigidity can then be very low and can be considerably increased outside the pressure range, for example to avoid loss of path of the component mounted in leaktight manner, with respect to to the work area. The choice of the force constant makes it possible to adapt the damping device to use cases, while keeping the geometry and configuration of the components substantially unchanged, which offers the advantage of using only one device. depreciation for various applications, not

  modifying that energy accumulators.

  According to a second aspect, the invention provides a damping device by means of which pressure oscillations or pressure pulsations of a hydraulic operating system of a clutch release coupling of a vehicle can be damped or eliminated, in which the operating system comprises for example a coupling pedal, maneuverable by the driver, which cooperates with a master cylinder, the latter is connected by a pressure line to a slave cylinder which acts on a coupling release stop clutch and the damping device which is connected to a component of the operating system and can be stressed by a pressurized fluid comprises a casing which is in one piece or consists of at least two components and in the space in which a closure body is slidably arranged, characterized in that the sealingly mounted closure body which rests on an element t elastic is stressed directly or indirectly by a pressurized fluid. The sealed closure body advantageously allows the elastic element to be separated, which has a favorable influence on the working mode of the damping device because the elastic element is thus independent of the influences of the pressure fluid. The invention allows the use of elastic elements of various structures which are preferably made of metallic materials or alternatively of elastomeric materials. The invention further includes elastic elements with various elastic constants which can be arranged in a predefined internal space. This results in a simple and flexible adaptation of the damping characteristic to various hydraulic operating systems, which can be produced for a limited cost. This also results in a cost advantage since it is the same structure which is used for the damping device adapted to various pressures and rigidities, with the exception of

the elastic element.

  The invention further makes it possible to influence in a simple manner the damping characteristic or damping effect by geometrically configuring the closure body and by specifying the elastic element, by means of a defined elastic constant or a defined elastic rigidity. , and the surface of the

  closure body subjected to pressure.

  According to an advantageous modality, it is a piston or an annular piston, the sealing of which on the pressure space side is for example produced by a sealing ring of the piston ring type, which is used as the closing body. in the damping device. At least one disc spring on which the piston or the annular piston bears elastically can be provided as an elastic element. Using a center hole disc spring can reduce

  the internal space required for the disc spring.

  The disc spring can be centered on a cylindrical appendage of the piston and rest on a front wall or on a limitation of the internal space. A helical spring on which the annular piston rests can be provided as an elastic element. Preferably, such a helical spring comprises

at least two spring turns.

  The invention also provides for the use of several disc springs which can be combined

in one or more packages.

  The disc springs are distinguished by a favorable structure, saving volume and economic and can preferably be combined with the piston of the damping device in a way which optimizes the necessary weight and space. The disc springs can be arranged in the same direction or in alternating directions to form a pack of disc springs on which the piston or the

  annular piston rests elastically.

  According to a variant, the internal space for receiving the piston can be provided, in the casing configured in one piece, in a part offset with respect to the line of pressure fluid of the fluid under pressure. An internal orientation space perpendicular to the direction of flow allows the use of a fully cylindrical piston whose seal rests on a sealing edge

  dynamics on the inner wall of the inner space.

  Such a piston seal allows a

  high sealing protection.

  The internal space can be closed by a cover which at the same time constitutes the end stop of the piston. Designed to ensure a high quality seal, it can also in certain ways serve as a stop for the piston. It can be screwed onto the housing, or be snapped into it, or brazed or

glued for example.

  The piston which acts as a closure body may comprise, to ensure its sealing, an annular groove or a peripheral recess formed on the front side to receive a tight seal which rests tightly on the outside on a

inner space wall.

  According to an advantageous modality, the damping device comprises a plug-in element which is introduced in positive engagement into a receiving element to form a casing. The plug-in element can be fixed in position on the receiving element at the

  by means of a cuff or sleeve.

  According to a variant, the device comprises a direct attachment in positive engagement between the receiving element and the plug-in element, for example a

snap connection.

  The circular annular internal space for receiving the annular piston, arranged concentrically with a line of pressurized fluid in the casing or in its receiving element can be connected to the line of pressurized fluid by means of a bypass channel. The sealing of such an annular piston is ensured by an annular seal, the sealing edges of which lie dynamically on the inner wall which surrounds, respectively.

  the internal space or on the central cleat.

  So that the support of the annular piston is elastic, it rests on a pressure spring on the side opposite the seal. Alternatively, one or more disc springs or a coil spring can be arranged in the internal space

circular in shape.

  On the side facing the bypass channel, the annular piston may comprise a projecting seal that rests sealingly on the appendage, by an inner dynamic sealing lip, and on a wall which surrounds the annular piston, by a

  dynamic outer sealing lip.

  The annular piston can bear in a damped manner on at least one compression spring. It can be one or more disc springs or, alternatively, the annular piston can rest on a helical spring arranged on the side opposite the circular annular internal space and housed in this

internal space.

  The damping device may include a throttle valve. This allows a pressurized fluid flow to be throttled or not, regardless of

the direction of the flow.

  It is a drilled disc arranged between the receiving element and the plug-in element in the area of the pressurized fluid flow pipe which can be provided as a throttling valve and which does not oppose any obstacle to the flow of fluid pressure in a first end position. In the other end position, the damping device allows a limited passage up to

  the throttle bore of the throttle disc.

  A spring, for example a helical spring, is preferably provided to urge the first throttle valve towards a throttle position. A helical spring which is supported on the plug-in element or the receiving element is particularly suitable for this purpose, and the throttle disc is supported by force on the other associated component. To optimize the number of components, the invention also includes a throttle valve arrangement the function of which is also guaranteed without separate spring to optimize the

structure.

  The invention specifically provides for the possibility of integrating the damping device with a

  component of the hydraulic operating system.

  The damping device can be arranged in the pressure line which connects the master cylinder to the slave cylinder, or the damping device is combined with a master cylinder, or the damping device can be arranged in the slave cylinder, either directly, either in its pressure tap which crosses the radial distance between this cylinder and the coupling housing, this latter solution being particularly advantageous for slave cylinders which are produced in the form of a central release stop. Due to the weight advantage of the damping device according to the invention, a pressure line which is provided with the damping device of the invention requires, for example, no other point.

of fixation.

  The invention includes for example a combination of the damping device of the invention and another oscillation damping element in the hydraulic operating system. The damping device and the damping element are

  based on different operating principles.

  The components assembled in a unit contain for example a resiliently supported closing body with which is associated a membrane box or a unidirectional pressure valve, mounted upstream or downstream. According to a third aspect, the invention provides a device for damping pressure oscillations in hydraulic systems, in particular in a hydraulic system for operating a vehicle clutch coupling, which comprises: a master cylinder to be maneuvered which is connected by a pressure line to a slave cylinder which activates a clutch release, and in which the pressure line or any component of the hydraulic operating system is connected to a damping member whose casing comprises a membrane to which a pressurized fluid can be applied, characterized in that the membrane structured to act as a cover is attached in positive engagement to the plastic casing and thus closes so

seals a housing chamber.

  This arrangement reduces the number of components because the membrane does not require, unlike the known state of the art, any other component for its fixing. The membrane produced in the form of a cover, is attached according to the invention in positive engagement on the casing and therefore closes a casing chamber in a sealed manner. The reduced number of components allows economical manufacturing of the

damping device.

  The invention also includes, in one form, a plastic casing in order to optimize the dead weight of the damping device. This advantageously results in the possibility of arranging the damping device inside the pressure pipe, without additional support. Suitable plastics are for example reinforced thermoplastics or else

duroplastic materials.

  The diaphragm can be in the configuration of a pot and can surround an appendage by a collar

cylindrical housing.

  An end portion of the collar can be applied to the rear of the appendix of the

casing while folded.

  The membrane can be attached by means of a snap connection arranged between the flange

and the housing.

  According to another embodiment, the sealing of the membrane is obtained using a sealing ring which is preferably arranged in a peripheral groove or a recess in the envelope surface of the cylindrical casing part that the membrane collar covers in assembled position. As a variant or in addition, a sealing ring can be arranged in a peripheral groove on the front side of the diaphragm support surface of the casing or on the outside side in a connection zone between the front side and the surface d casing 7 which is

surrounded by the membrane.

  It is possible to provide a casing which is provided with two membranes configured in a pot and diametrically

opposite.

  It is also possible to provide a membrane which is provided with a domed bottom of the casing which has a

  bulge towards the casing or towards the outside.

  One can in particular provide a casing which is provided with two radially oriented pipe fittings, or alternatively, the casing can be provided with two pipe fittings oriented parallel to each other and

perpendicular to the membrane.

  The pressure lines can be connected by plug-in connections on the

  damper pipe connections.

  To retain the pipe connection, it is possible to provide a shaped spring which is arranged in a captive manner in the pipe connection of the casing and which, for example, automatically snaps into an annular groove of the connector in the mounted position of the

  pressure line connector.

  According to one form, the invention provides a damping member in which the damping space is in the form of a labyrinth. This labyrinth increases the residence time of the oscillations of the pressure fluid in the damping member which can therefore act longer on the membrane. This arrangement therefore improves the damping characteristic of the damping member. One can provide a damping member whose casing has, connected to the membrane, a flexibility, or a rigidity, defined so as to achieve a determined damping. The membrane therefore allows, in cooperation with the casing, a desired increase in volume, depending on the

hydraulic fluid pressure.

  It can be provided that the membrane can be arranged in a recess in the housing, the membrane rests on a support, a retaining ring is arranged in front of the membrane and an edge situated on the housing side is folded at least in sections towards inside to fix these

components.

  A seal can be arranged in a peripheral annular groove located on the front side and formed in the support and rest under

  preload on the diaphragm in the assembled state.

  The device may comprise a damping member which is connected to a component of the hydraulic operating system, for example the master cylinder, the slave cylinder or the pressure line, or which is integrated in one of these

components.

  According to a fourth aspect, the invention provides a damping device for pressure oscillations or pressure pulsations in hydraulic systems, in particular in a hydraulic system for operating a clutch release coupling of a vehicle, in which the system maneuver comprises a master cylinder which is connected by a pressure line to a slave cylinder which activates the clutch release, the damping device which is connected to the maneuvering system comprises a casing provided with at least one pipe connection and a membrane as well as a retaining element which constitutes a stroke limitation for the diaphragm, characterized in that a recess surrounded by an edge is formed in the casing to receive the diaphragm in front of which a retaining element is fixedly in

position is housed.

  According to a fifth aspect, the invention provides a damping device for pressure oscillations or pressure pulsations in hydraulic systems, in particular in a hydraulic system for operating a clutch release coupling of a vehicle, in which the system maneuver comprises a master cylinder which is connected by a pressure line to a slave cylinder which activates the clutch release, the damping device which is connected to the maneuvering system comprises a casing provided with at least one pipe connection and a diaphragm and a retaining element which constitutes a stroke limitation for the diaphragm, characterized by a plastic casing which is combined with a spring steel diaphragm and with a plastic or steel retaining element

that surrounds the membrane.

  According to a sixth aspect, the invention provides a damping device for pressure oscillations or pressure pulsations in hydraulic systems, in particular in a hydraulic system for operating a clutch release coupling of a vehicle, in which the system maneuver comprises a master cylinder which is connected by a pressure line to a slave cylinder which activates the clutch release, the damping device which is connected to the maneuvering system comprises a housing provided with at least one pipe connection and a diaphragm and a retaining element which constitutes a stroke limitation for the diaphragm, characterized by a disc-shaped housing which is integrated together with the diaphragm in a

retained in pot configuration.

  The pipe connections can be arranged inside a circular external contour of the casing. This arrangement can make it possible to reduce the internal space required. The device can comprise an aluminum casing, preferably made by extrusion, in which a spring steel membrane is integrated.

  as well as a metal retaining element.

  The device may include a retaining element which has a central projection which approaches the membrane while maintaining an interval of defined dimension, in the neutral position of the membrane. The device may include a retaining element, the edge of which surrounds an outer zone of the casing and the free end of which, in the assembled position, is applied to the rear of an appendage of the

  casing by being folded inwards.

  The edge can be attached in positive engagement to the cylindrical shell surface of the housing by means

a snap connection.

  The connection between the edge of the retaining element and the casing may consist of a connection called by material, that is to say typically by bonding, soldering, welding, ultrasonic welding, etc. A sealing ring which presses tightly on the diaphragm in the mounted position can be arranged on the front side in a peripheral groove of the casing to seal the diaphragm. A sealing ring which presses tightly under prestressing, in the mounted position, on the inner side on the edge can be arranged in an annular groove of the housing between the housing and the edge.

of the retainer.

  The device may comprise a disc-shaped retaining element with a conical outer contour, which is arranged in a corresponding recess in the casing and which is connected to the casing by material in the mounted position in the area of the bearing surface defined in the recess provided to hold the membrane. The device can comprise a casing in which two membranes are arranged at a distance from one another and parallel to each other, a retaining element being associated with each of them on the outside. The device can include a casing whose pipe connections are oriented

perpendicular to the membrane.

  Provision may be made for a damping space of the casing which is closed laterally by the membrane to be

in the shape of a labyrinth.

  The damping device can be integrated into one of the components of the hydraulic operating system, for example the master cylinder or the slave cylinder or the pressure line, or

is connected.

  The membrane and the retaining element can be fixed in position by folding or folding at least

edge sections.

  According to a seventh aspect, the invention achieves, to achieve this goal, a device for damping pressure oscillations and / or pressure pulsations in a hydraulic operating system of a vehicle clutch coupling, comprising a support of valves on which two radially offset and elastically biased valve elements are supported which each form a valve seat with the valve support, characterized in that the valve elements of cylindrical configuration, associated with different directions of the pressurized fluid are guided in the valve support and a bypass channel, the cross-sectional area of which increases at least partially as a function of the longitudinal extension, therefore of an opening stroke of the valve element, is associated with each of the valve elements in the valve support and arranged in parallel to a longitudinal axis The bypass channel, unique for each valve element, formed in the valve support parallel to the longitudinal axis of the valve element provides stable support of the valve element on the guide of the valve support in the open position. The bypass of the valve element on one side, which replaces the usual arrangement hitherto with several bypass channels distributed on the periphery, causes the flow pressure of the pressurized fluid to urge the valve element d 'such that it rests more calmly on the valve support on the side opposite the bypass channel. This effectively prevents the development of noise caused by indifferent states of the valve member. The arrangement of the bypass channel according to the invention therefore avoids an opening flap, that is to say a rapid succession of periodic lifting and closing of the valve element relative to the valve seat. In the state of the art, the opening beat of the valve element is transmitted in the hydraulic operating system to the pedal and generates a

  unpleasant impression on the pedal.

  The enlargement of the flow area of the bypass channel takes place independently of the stroke of the valve element, that is to say of lifting of the valve element. This constructive arrangement favorably influences the operation of the damping device and represents additional safety in relation to a flapping.

  valve element opening.

  According to an advantageous embodiment, the valve support comprises to form the valve seat a supply channel whose diameter is less than that of the valve element, and which comprises, projecting in an axial direction, an appendage on which the The valve element is supported by a region of its front surface which is offset inwards relative to its external contour. Such a valve seat guarantees a defined support of the valve element, which makes it possible to achieve the damping characteristic

  damping device.

  The axially projecting appendage in the valve support has an undercut in the form of an annular channel offset radially relative to the appendage or to the valve seat. The bypass channel, the route of which is on one side on the valve element, is connected starting from the annular channel, therefore from the undercut. This valve seat according to the invention satisfies on the one hand the requirement for an effective seal when the valve element is closed and on the other hand avoids an opening beat of the valve element, independently of its degree of openness. Immediately after lifting the valve element which moves it away from the valve seat, the entire front surface of the valve element is stressed by the pressurized fluid, due to the undercut in the form of an annular channel, this which avoids an incorrect position of the valve element. The flow pressure which is established after opening on one of the sides ensures stable support of the valve element on the valve support during the entire stroke of the valve element.

valve.

  To allow almost constant resistance to flow, the invention provides that the bypass channel is continuously enlarged, starting from the annular channel, over the entire longitudinal extension. This ensures that the flow of pressurized fluid which increases with the opening of the valve element bypasses the valve element almost without resistance, or by encountering a

  constant resistance to flow.

  The bypass channel can be configured according to the invention in such a way that its bypass channel has a first section which expands more than proportional to the stroke of the valve element and a second section which connects to the first and of which the cross section increases

  in proportion to the stroke of the valve element.

  Preferably, the maximum cross section of the bypass channel is greater than the cross section of the supply channel of the damping device. It is advantageous for this purpose that the cross-sectional area of the bypass channel is at least 5% greater than that of the

inlet channel.

  To optimize the flow, the configuration of the inlet channel is preferably in the form of a venturi on the end opposite the valve seat. Other provisions designed to favorably influence the flow provide that the cross-sectional configuration of the profile of the bypass channel may be in an arc of a circle, and / or that the valve element may include appendages.

  frustoconical on its two front faces.

  Advantageous linear contact of the valve element on the appendage of the seal support located upstream is ensured according to the invention by the fact that the appendage of the valve support, located axially projecting, forms an oblique or conical surface characterized by the angle "a", on which the front surface of the valve element rests. The linear support of the valve element causes a limited sealing interval which already allows, even for the smallest stroke of the piston, a flow of the pressurized fluid which favorably influences the state of the valve element. This constructive provision meets the requirement of a stable state of

  the valve element in the open position.

  According to an advantageous method, the frustoconical appendage on the side of the valve element which is opposite to the valve seat is used to center in position the compression spring which exerts a force component in the direction of the valve seat on

the valve element.

  Preferably, the valve element has rotational symmetry, which eliminates the need for oriented mounting. This configuration, which makes it possible to avoid oriented mounting, in particular avoids any defect in

associated mounting.

  The compression spring can be centered on a component, associated with the valve support, in the casing, which for this purpose has an appendage, the front surface of which constitutes a limit stop for

the valve element.

  The valve element can be guided by sliding, tolerating a mounting clearance> 0.01 mm in the

valve support.

  The device can comprise a sealing element made of metallic material, in particular steel, as well as a valve support made of plastic material which are integrated in the plastic housing. The objects, features and advantages of the invention set out above, as well as others, will be more apparent to those skilled in the art from this.

  referring to the following description taken in conjunction

  with the accompanying drawings in which: Figure 1 shows a damping device whose closure body is arranged perpendicular to the direction of flow; Figure 2 shows the structure of a closure body of circular annular configuration which is arranged concentrically with the pressure fluid line of the damping device; Figure 3 shows a circular annular closure body which rests on a helical spring; Figure 4 shows a damping device which applies two different principles of intervention; Figure 5 shows a variant of the damping device of Figure 3, in which a throttle valve is integrated; Figure 6 shows the damping device of Figure 5 in which the throttle valve is shown in the closed position, that is to say the throttle position; Figure 7 shows a damping device whose housing is constituted by a receiving element and a plug-in element, which are connected together in positive engagement; Figure 8 shows a damping device according to the invention integrated in the master cylinder; Figure 9 shows a slave cylinder in the pressure tapping of which a damping device is installed; Figure 10 shows a sectional view of the structure of the membrane which is attached to the housing by means of a folded end region; Figure 11 shows a membrane which is mounted by means of a snap connection on the casing, the damping space of which comprises a labyrinth; Figure 11a is a sectional view along line 2a - 2a of Figure 11; Figure 12 shows a domed bottom membrane of the housing; Figure 13 shows a housing of a damping member with two membranes, each having a domed housing bottom; Figure 14 shows a damping member with pipe connections oriented parallel to the axis of the membrane; Figure 15 shows a damping member with axially oriented pipe fittings to the membrane, which is fixed in position according to Figure 6; Figure 16 is a block diagram of the structure of the hydraulic operating system; FIG. 17 represents a retaining element and a membrane connected to each other and arranged in common in a recess situated on the front side of the casing, a peripheral edge of the casing being folded inwards for fixing in position ; Figure 18 shows an alternative structure of the damping device in which the pot-shaped retaining element is attached to a cylindrical part of the casing; Figure 19 shows a damping device in which the disc-shaped housing and the membrane are integrated in a pot-shaped retaining element; FIG. 20 represents a damping device, the membrane of which is surrounded by a retaining element which includes an end of stroke limitation; FIG. 21 represents a retaining element made without chips from a sheet and with which is associated a disc type membrane; Figure 22 shows a damping device, the casing of which comprises two parallel membranes spaced from one another; Figure 23 shows a damping device comprising a labyrinth arranged in the damping space of the casing; Figure 24 is a sectional view of the damping device along line 8-8 of Figure 23; Figure 25 is a principle representation of the structure of a hydraulic operating system; Figure 26 is a longitudinal sectional view of the damping device according to another aspect of the invention; Figure 27 shows on a larger scale the valve element of Figure 26 in the closed position; Figure 28 shows the valve member of Figure 27 in the open position; Figure 29 shows the valve element of Figure 27, in a variant configuration of the valve element; Figure 30 is a view, in the direction of the arrow in Figure 29, of the configuration of the bypass channel and the valve element receiver in the valve holder; Figure 31 shows the flow characteristic through the damping device according to the invention; and Figure 32 shows the flow characteristic in a valve member of conventional configuration. Figure 1 is a longitudinal sectional view of a damping device according to the invention. The damping device 1a made in one piece is intended to be mounted in a pressure pipe not shown which connects between them a master cylinder and a slave cylinder of the

  hydraulic operation of a clutch coupling.

  The structure comprises a casing 2 with two pipe connections produced in the form of plug-in connections 3, 4. The casing 2 comprises, perpendicular to its longitudinal axis 5, an appendage 6 which constitutes a cylindrical internal space 7 in which is arranged a body of piston-shaped closure 8. The internal space 7 is closed by a pot-shaped cover 9 whose edge 10, which is folded radially inwards at its end, in sections or over the entire periphery, is snapped radially in an annular groove 11 in the appendix 6. The piston 8 is pressed elastically on the cover 9 by means of disc springs 12. The disc springs 12, drilled and assembled in a package respectively are

  centered on a cylindrical appendage 13 of the piston 8.

  According to Figure 1, the disc spring package comprises two disc springs 12 stacked in opposite directions as well as two disc springs stacked in the same direction. This different arrangement of the disc springs 12 makes it possible to influence the rigidity and therefore the damping characteristic with respect to the pressure oscillations which appear in the

hydraulic operating system.

  In the direction of the longitudinal axis 5,

  that is to say of the line 21 of pressurized medium in the casing 2, the piston 8 is provided with a seal 14 which is produced in the form of an annular seal with grooves. The seal 14 arranged in an annular groove 18 is supported by a static sealing edge 16 on the groove bottom of the groove 18. The other dynamic sealing edge 17 is on the other hand applied sealingly to a wall inside 19 of appendix 6. Applying pressure to the piston 8 results in moving the piston 8 in the direction of the arrow. The cover 9 which for this purpose comprises a step 20 adapted to the appendage 13 of the piston 8 constitutes an end of stroke limitation for the piston 8. The maximum stroke "h" is defined here by the distance represented in FIG. 1 between a front surface of appendix 13 and the cover

9 in the tier 20 area.

  The damping device 1b shown in FIG. 2 comprises two casing elements, a receiving element 22a and a plug-in element 23a which penetrate into each other in positive engagement and

  are kept assembled by means of a cuff 24a.

  An annular piston 25 which is guided concentrically with respect to the pipe 21 of pressurized fluid, therefore to the longitudinal axis 26, on an appendage 27a of the receiving element 22a serves as a resiliently supported closure body. On the appendage 27a are also guided disc springs 28 arranged in opposite directions alternately between the annular piston 25 and a shoulder 29a of the receiving element 22. The annular circular internal space a which is limited on the inner side by the appendage 27a and is intended to receive the annular piston 25, is completely surrounded on the outside by the wall 31a of the plug-in element 23a. The annular piston 25 in disc configuration carries on the front face, on the side of the pressure space, the watertight seal 32 whose dynamic sealing edges 33, 34 are pressed in leaktight manner, during an axial displacement of the annular piston 25, on the appendage 27a or on an inner wall 35 of the plug-in element 23a. To apply pressure to the internal space 30a, a bypass channel 36, through which the pressurized fluid arrives from the line 21 of pressurized fluid in the internal space 30, is provided on a

  lateral side of the plug-in element 23a.

  The annular piston 37 of the damping device lc shown in Figure 3 has a L-shaped cross-sectional profile and is supported in the neutral position on the front side by an edge 38 on the wall 31b. A ring 39 with a square cross-section which rests in a tightly mounted state on the wall 31b or on an envelope surface of the appendage 27b seals the annular piston 37. The internal space b arranged concentrically with respect to the pipe 40 of pressurized fluid is connected to the pipe 40 of pressurized fluid by a bypass channel 41 connected to a longitudinal channel 42 configured as a recess in the plug-in element 23b. The elastic support of the annular piston 37 results from the effect of a helical spring 43 which is supported on the shoulder 29b by one end of the spring and on the front side by the other spring end on the annular piston 37. The cuff 24b which assembles the receiving element 22b and the pluggable element 23b simultaneously encloses the helical spring 23. The maximum stroke of the annular piston 37 which is designated by the dimension "h" in the drawing is established in the neutral position between the annular piston 37 and a stop 53 of the receiving element 22b. As an alternative to the ring 39 with a square cross section, a rolling membrane which reduces friction can be provided for sealing the

the internal element 30b.

  Fig. 4 shows a damping device 1d which consists of a combination of two independent resiliently supported closing bodies, based on different operating principles. With an annular piston which corresponds in structure and function to the annular piston shown in Figure 2 are associated two other closure bodies arranged in the direction

  axial, with valve body configuration 44a, 44b.

  The valve bodies 44a, 44b arranged radially offset in the disc structure valve element 46 are each produced in the form of a unidirectional valve, that is to say a valve which allows only one direction flow. The relatively small valve bodies 44a, 44b, of totally cylindrical configuration, are guided in axial sliding in the valve element 46 and each constitute

  with the valve element 46 a valve seat 47a, 47b.

  A helical spring 45a, 45b, the other spring end of which is centered on an appendage 48a, 48b of the receiving element 22c or of the plug-in element 23c, is disposed in each of the two valve bodies 44a, 44b. opposite the valve seat 47a, 47b. After having been lifted away from its valve seat 47a, 47b, each of the valve bodies 44a, 44b which opens in the direction of the arrow allows the passage of a pressure fluid via an overflow channel 49a, 49b which is formed in the valve element 46. The damping device shown in Figures 5 and 6 largely corresponds, in terms of its structure, to the damping device lc shown

  in Figure 3. The following description is not for

  so that the throttle valve 54 integrated so

  additional in the damping device on.

  As a throttle valve 54, a disc 55 is used which rests on the front side on the receiving element 22 and is guided on the outside side in a housing 64 of the plug-in element 23b. The position of the disc 55 shown in Figure 5 is comparable to the free passage of the throttle valve 54 o the pressurized fluid reaches the line 21 of pressurized fluid both through the central throttle bore 62 and by l '' recess 65 in the housing area 64 of the plug-in element 23b and the overflow channel 63

of the receiving element 22b.

  The throttle position of the throttle valve 54 is shown in Figure 6. The disc 55 here lies flat on the outside on an appendage 61, oriented radially inwardly, of the plug member 23b and constitutes a valve seat 60. In this position of the disc 55, the pressurized fluid guided in the direction of the arrow through the pipe 21 of pressurized fluid can only pass exclusively through the central throttle bore 62 of the throttle valve 54. It is a compression spring 59 placed between the receiving element 22b and the disc 55 which maintains the disc in an elastically prestressed position which

  corresponds to the throttling position.

  Figure 7 shows the damping device if, the structure of which differs from the damping device lc of Figure 3 by a modified attachment of the receiving element 22d on the plug-in element 23d. As an alternative to a cuff attachment, the outer wall 66 of the plug-in element 23d has at least one recess 57 in which a latching cleat 58 of the receiver element 22d engages in positive engagement in the mounted position. In order to allow an elastic radial excursion without problem of the external wall 66 when the receiving element 22d is inserted into the plug-in element 23d, the external wall 66 comprises at least one longitudinal slot 67. The external wall 66 preferably comprises several recesses 57 arranged in a distributed manner on the periphery and formed in the outer wall 66 in

  alternating with longitudinal slots 67.

  Figure 8 shows a master cylinder 50 which is combined with a damping device 1a shown in Figure 1. The individual components of the damping device 1a are designated by the same reference numerals as in Figure 1, so

  that should be referred to, for their description,

  to the embodiment of Figure 1. Figure 8 clearly shows the possibility of combining the damping device la of the invention with the master cylinder without the necessary internal space

is significantly increased.

  Figure 9 shows a slave cylinder 51 whose pressure tap 52 is provided with the damping device la. This arrangement also increases only insensitively - the internal space required and thus allows an optimized combination, in terms of the number of components and the internal space required, between a component of the operating system and the damping device. of the invention. In Figure 10 is shown a damping member 0lla according to the invention which comprises a plastic casing 102a. The casing 102a provides a damping space 103 open in a cylindrical manner on one of its sides and provided with two connections 104, 105 of pipes oriented radially outwards to connect pressure pipes 106, 107 which establish a connection with a master cylinder 108 and a slave cylinder 109, as shown in FIG. 16. The damping space 103 is closed by a membrane 110a preferably made of metallic material produced as a pot-shaped cover. The membrane 110a surrounds by a peripheral flange 111 a cylindrical end region of the casing 102. In order to achieve, by positive engagement, a fixing in position of the membrane 110a on the casing 102a, a free end portion 113 of the flange 111 is folded radially inwardly in sections or over the entire periphery and is thus applied to the rear of an appendage 112 of the casing 102a. A peripheral groove 114 formed in the envelope surface of the appendage 12 serves to receive a sealing ring 115a which rests under stress in the mounted state on the inner side of the flange 111 and which thus ensures a guaranteed tightness of the

  membrane 11Oa against the casing 102a.

  Figure 11 shows the damping member 101b which differs from the damping member 10la of Figure 10 by a variant of attachment of the membrane 110b on the casing 102b. For this purpose, the flange 111 of the membrane 11Ob has recesses 116 or openings distributed over the periphery, in which retaining cleats 117 connected in one piece to the casing 102b automatically snap into the assembled state of the membrane 11Ob and thus ensure a lasting bond

of the 11Ob membrane.

  The sectional view of Figure 11a, along the line 2a-2a of Figure 11, shows the configuration of the damping space 103. This includes a labyrinth 128 that the pressurized fluid must follow as it passes through the damper 10lb. Labyrinth 128 extends the residence time of the pressure fluid, which has a positive effect on

  damping pressure oscillations.

  The damping member 10lc of Figure 12 is provided with a diaphragm 11Oc with a curved bottom, that is to say swollen, 118 of the casing. The bulge of the bottom 118 of the casing is here oriented in the direction of the damping space 103. Another difference between the damping member 101c and the damping members 0lla and 0llb of Figures 10 and 11 concerns the sealing of membrane 110c. To this end, the sealing ring 115b is arranged in a connection zone between the cylindrical envelope surface and the support on the front side of the membrane 110c in a corresponding recess 119 in the casing 102c. To attach the 110c membrane, its flange

  111 is tightened on the appendix 112 of the casing 102c.

  As a variant, an attachment between the membrane 110c and the casing 102c can be made by material, by

example by gluing or welding.

  FIG. 13 represents the damping member 0lld which surrounds a casing 102d of tubular configuration, the openings of which are closed each by a membrane 110d. The two membranes 11Od- are of identical configuration and are provided with a domed bottom, that is to say swollen, towards the outside, 120 of casing. The attachment of 110d membranes is identical to

  that of the membrane 110b, shown in Figure 11.

  Unlike all the members 0lla to 101d described so far, the damping member 0lle of Figure 14 has a casing 102e, the fittings 104, 105 of pipes of which are oriented parallel one

  to each other and perpendicular to the membrane 110e.

  To attach the membrane 110e to the casing 102e, its flange 111 extends over a remote cylindrical end portion of the casing 102e and is connected to it in a non-removable manner, by material, preferably by welding or gluing. Alternatively, a

* snap connection can also be provided.

  To seal the membrane 110e, a sealing ring 115b is arranged at the free end of the casing surface of the casing 102e in a recess 119, which is therefore comparable to

  the tightness of the llOc membrane according to Figure 12.

  Figure 15 shows in cross-sectional view the damping member 101f in which the pipe connections 104, 105 are oriented perpendicular to the membrane 110f. The membrane f is here arranged in a recess on the front side of the casing 102f and is supported on a circular annular support 124 of the casing 102f. A retaining ring 121 is placed in front of the membrane 110f. To fix the position of the retaining ring 121 and therefore of the membrane 110f, the edge 125 of the casing 102f, which surrounds the recess 123, is folded inwards

  to make a tie in positive engagement.

  The sealing of the membrane 110f with respect to the casing 102f results from a sealing ring 115c which is arranged in an annular groove 122 situated on the front side of the support 124 and which is supported

  waterproof on the membrane 110f in the assembled state.

  The block diagram of Figure 11 shows all the essential components of a hydraulic operating system 129 of a vehicle clutch release coupling. According to this diagram, the master cylinder 108 is connected to a coupling pedal

  26, operated by the driver, or to an actuator -

  not shown here - which can be actuated electrically and which causes an axial displacement to maneuver the piston rod of the master cylinder 108. The pressure line 106, 107 makes it possible to transmit, from the master cylinder 108, a pressure of fluid under pressure to the slave cylinder 109 connected to a clutch coupling 127. A damping member 0lla is arranged to dampen pressure oscillations which are transmitted from a combustion engine to the hydraulic operating system 129 via the clutch coupling 127. According to the invention, the member d 'damping 0lla can be arranged in the master cylinder 108, in the slave cylinder 109 or between the pressure lines 106 and 107. There is no fixed association between one of these elements and the damping member 10la: the latter may well rather be associated at will with any one of the three elements of the hydraulic operating system 129. In this way the arrangement of the damping member 1a shown in FIG. 16 must be considered as an example of assembly which can be advantageous for all the methods exposed in the documents of the present request. It is understood that the arrangement of the other components, for example an arrangement of the master cylinder around the input shaft of the gearbox or at another location with corresponding transmission means such as rods can be examples of realization of the concepts of the invention. The damping device 101a can also be integrated into one of the other components of the hydraulic circuit, for example in the master cylinder 108

or in the slave cylinder 109.

  Figure 17 shows, in cross-sectional view, a damping device 201a in which a membrane 205a and a retaining element 206a are arranged in a recess 221 on the housing side. To fix the position of these arranged components, an edge 222 of the casing 202a is folded or folded inwards at its end, at least in sections, and thus comes to be applied to the rear of the external contour of the element of retainer 206a and membrane 205a. The sealing of a pressure space 203, on the membrane side, results from a sealing ring 210 which is arranged in the external zone of the bearing surface of the membrane 205 in a peripheral groove 211 of the casing 205 and rests under tight prestress on the membrane 205a. The retaining element 206a is curved, that is to say swollen towards the outside, and thus allows a stroke limitation for the membrane 205a. The pipe connections 212, 213 are arranged

  parallel to the membrane 205a in the casing 202a.

  The pipe connections 212, 213 are arranged inside the external contour of the casing 202a, which underlines the compact structure of the device

depreciation 201a.

  The damping device 201b shown in FIG. 18 comprises as components a retaining element 206b and a casing 202b which are made of

  plastic to adapt to each other.

  The pot-shaped retainer 206b surrounds the edge 207b with an end region of the casing 202b of cylindrical configuration. In the mounted position, the retaining element 206b is spaced axially from the steel membrane 205b, an axial distance "s" limiting a maximum excursion of the membrane 205 and thus ensuring effective stroke limitation for the membrane 205b. To fix in position the retaining element 206b on the casing 202b, these two elements being made of plastic to adapt to each other, a connection by material is particularly suitable, for example welding or bonding in the area of the bearing surface of the edge 207b on the envelope surface of the

casing 202b.

  The damping device 201c of FIG. 19 has a compact structure, optimized as regards the internal space. For this purpose, the casing 202c, preferably made of plastic, is in disc configuration and is integrated in common with the membrane 205c in the retaining element 206c in jar configuration. The retaining element 206c here surrounds at least radially the casing 202 and completely the membrane 205c. The edge 207c of the retaining element 206c here extends over the width of the membrane 205c and the

  housing 202c. At the free end of edge 207c, this

  it is folded inwards in sections or over the entire periphery and is applied in positive engagement on the rear of the outer contour of the casing 202c. To form the damping space 203, the casing 202c comprises, on the membrane side, a circular annular recess which is covered by the membrane 205c. To seal the damping space 203, the sealing ring 210 which rests on the membrane 205c in the assembled state is arranged on the front side in a peripheral groove 211 of the casing 202c. Opposite the casing 202c, the membrane 205c rests on the outside on a spacer 223 produced in the form of a sealing ring which is arranged as an independent part in the retaining element 206c and which ensures a distance axial between the bottom 225 of the retaining element 206c and the membrane 205c. A rib 224 which forms a bulge on the membrane side and is mounted in the bottom 225 of the retaining element 206c defines an interval dimension and simultaneously constitutes a stroke limitation of the

membrane 205c.

  Figure 20 shows, in cross-sectional view, the damping device 201d. The structure comprises a casing 202d which constitutes a cylindrical damping space 203 closed on one side by a bottom 204. On the side opposite the bottom 204, the casing 202d is closed on the front side by a membrane 205d. The retaining element 206d is arranged in front of the diaphragm 205 in disc configuration, preferably made of metallic material. The retaining element 206d which is preferably made of sheet steel, without machining by chip removal, by a deep drawing process, surrounds by the peripheral edge 207d a cylindrical end part of the casing 202d. To fix the position, a free end of the edge 207d is folded or folded inwards and is applied to the rear of a radial appendage 208 of the casing 202. In the mounted position, the retaining element 206d is arranged at an axial distance from the membrane 205 by means of an edge 207d which comprises a step radially. A central projection 209 of the retaining element 206d is oriented towards the membrane 205d and is spaced from the membrane 205d, in the mounted position, by an interval dimension "s". The sealing ring 210 which is arranged in a peripheral groove 211 on the front side of the casing 202d and which is supported under preload, in the assembled state, 4 on the membrane 205d achieves an effective sealing of the pressure space 203. The casing 202d is provided with two connections 212, 213 of pipes which exit radially and are produced in the form of plug-in connections for connecting pressurized pipes by which connections can be established to a master cylinder 227 and a slave cylinder 230 of the hydraulic operating system according to FIG. 25. The pipe connections 212, 213 can be arranged as desired on the casing 202d which is preferably made, to optimize the weight, of plastic material by a pressure molding process, for example a

  thermoplastic material or duroplastic material.

  FIG. 21 shows the damping device 201e, the sheet metal retaining element 206a of which furthermore has, in the region of the edge 207e, a seal to seal the membrane 205e. To this end, an annular groove 215 is formed in the envelope surface of the casing 202e to receive the sealing ring 214 which rests under prestressing on the inner side on the edge 207e of the retaining element 206e. The tightness of the membrane 205e with respect to the casing 202e corresponds to the variant shown in Figure 20. The retaining element 206e is arranged in a large area, at an unchanged axial distance from the membrane 205e. To attach the retaining element 206e, it can for example be attached by gluing or by welding between the edge 207e and the casing 202e. A tight connection between these

  components may also be appropriate.

  The damping device 201f of Figure 22 includes two membranes 205f arranged parallel to each other on the casing 202f. To this end, the casing 202f has on each of its front sides a recess 216 which constitutes a circular annular bearing surface 217 on which the membrane 205f rests. The retaining element 206f is in front of the membrane 205f and is supported by an external flange 218 on the membrane 205f. The flange 218 projecting axially from the bottom 219 of the retaining element 206f defines, for an interval formed between the bottom 219 and the membrane 206f, a dimension which limits the amplitude of oscillation of the membrane 206f and thus constitutes a limit switch. From the bearing surface 217, the recess 216 of the casing 202f is of conical shape, that is to say that it widens radially. The outer contour of the retaining element 206f conforms to this configuration and correspondingly adapted in positive engagement. To achieve an effective tight connection between the plastic components which fit together, the retaining element 206f and the casing 202f are connected by material, in particular by ultrasonic welding, in the surface of contact formed by the recess. In

  variant, a bonding would for example be appropriate.

  In this structure, it is possible to omit a separate seal between these components by means of a

watertight ring.

  Figures 23 and 24 show the damping device 201g with membrane 205c and retaining element 206c which conform in configuration and arrangement to the components of Figure 19. Consequently, these are also designated by similar alphabetical references. The damping space 203 of the damping device 201g forms a labyrinth 220, the structure of which is shown in FIG. 24. Since the membrane 205c rests on the front side on the individual segments of the labyrinth 220, the fluid under pressure follows the shape of the labyrinth when it passes through the damping device 201C. The labyrinth advantageously prolongs the residence time of the pressure oscillation or the pressure pulsation in the damping device 201g, which influences the damping characteristic and in this way promotes damping and therefore comfort of use of the hydraulic operating system for the clutch release which

is improved.

  The principle representation of FIG. 25 represents all the essential components of a hydraulic operating system for a vehicle clutch coupling 229. The master cylinder 227 is here connected to an actuator 228 or to a coupling pedal to be operated by the driver. Transmission of a pressure of fluid under pressure, from the master cylinder 227 to the slave cylinder 230 connected to a clutch clutch 229, takes place via the pressure line 231, 232. A damping device 201a is arranged to dampen pressure oscillations which are transmitted from a combustion engine to the hydraulic operating system 226 via the clutch clutch 229. According to the invention, the damping device 201a can be arranged in the master cylinder 227, in the slave cylinder 230 or between the pressure lines 231, 232. There is no fixed association between one of these elements and the damping member 201a: the latter may rather be associated at will with any one of the three elements of the hydraulic operating system 226. The arrangement shown in Figure, must therefore be considered as an example of mounting the damping device 201a. Figure 26 shows a damping device 301 which comprises two housings 302, 303, with rotationally symmetrical configuration, assembled one inside the other in positive engagement. The housings 302, 303 are each provided with a plug connection 304, 305 for connecting, for example, pressure lines by means of which the damping device 301 is connected to a master cylinder and to a slave cylinder of the hydraulic operating system d '' a clutch release. The casing 302 receives, on the end opposite to the plug connection 304, a support 306 of cylindrical configuration valve which is supported on a shoulder 307 of the casing 302. In the casing 302 is further inserted an appendage 308 of the casing 303 which is located on the front side thereof and rests in the position mounted on the valve support 306. The valve support 306 as well as the appendix 308 of the casing 303 are respectively arranged in a sealed manner in the receiver, located on the end side, of the casing 303. For this purpose, sealing rings 312a, 312b are provided which are each arranged in an annular groove of the valve support 306 or of the appendage 308 of the casing 303 and which rest in leaktight manner on a wall 311 of the bore of the casing 302. All the components of the damping device 301 are held together captively by means of a sleeve 309 which surrounds the assembled parts of the casings 302, 303. To ensure correct positioning, the sleeve 309 comprises, on the front sides, flaps 310a, 310b

  oriented radially inwards.

  The valve support 306 serves to receive and guide two valve elements 313 and 314 arranged radially offset. In the extension of a supply channel 328 formed in the valve support 306, two appendages 315, 316 each form a valve seat 317, 318 for the corresponding valve element 313, 314. The arrangement of the valve elements 313, 314 is such that these valves can open in different directions of flow, designated by arrows. Each valve element 313, 314 is associated with a compression spring 319, 320 which rests by one spring end on the casing 302, 303 and the other spring end of which rests on the valve element 313, 314 and exercises a component

  force towards the valve seat 317, 318.

  When the element 313, 314 in which the pressure of the pressurized fluid displaces the force of the compression spring 319 is opened, the valve element 313, 314 moves away from the valve seat 317, 318 and the pressurized fluid can bypass element 313,

  Valve 314 through bypass channel 321, 322.

  Figures 27 and 28 show on a larger scale the arrangement of the valve element 313, 314. In the neutral position, that is to say in the closed state of the valve element 313, it rests sealingly on the valve seat 317, as shown in FIG. 27, under the effect of the force of the compression spring 319. The compression spring 319 is centered for this purpose on the casing side on an appendage 323 whose front face 324 forms an end of stroke limitation for the valve element 313. A flow can bypass the valve element 313 only when the force exerted by the pressurized fluid which acts on the front surface of the valve element 313 exceeds the force of the compression spring 319 which opposes it and that l the valve element 313 lifts from its valve seat 317, as shown in Figure 28. The pressurized fluid bypasses the valve element 313 by passing only through a single bypass channel 321 which is formed in the support 306 valve parallel to a longitudinal axis 326. This bypassing the valve element on one side, designated by an arrow, causes a force bias on one side of the valve element 313. This ensures a stable state of the position of the valve element 313 on a bore wall 326, which effectively remedies any unstable state, that is to say any "opening beat".

of valve element 313.

  To form the valve seat 317, the appendix 315 is arranged in the valve support 313 in such a way that the valve element 313 rests on

  the appendix 315 by the frontal surface 327, that is to say

  say radially offset from the

  casing surface of valve member 313.

  Appendix 315 is here beveled on its front side, that is to say that an undercut area, designated by the angle "a" is connected to the interior support area. This configuration achieves a linear type sealing zone, that is to say that a desirable sealing space of small dimensions is provided between the valve element 313 and the appendage 315. In this way, even a short stroke of the valve element 313 allows access of the pressurized fluid for reduced flow resistance, and allows accelerated bypassing of the element 313

  valve through bypass channel 321.

  The configuration of the valve support 306 ensures that the pressure fluid is supplied centered relative to the front surface 327 of the valve element 313. The inlet channel 328 has a venturi-shaped inlet to optimize the flow of the fluid. The flow channel 328 forms the seat 317

  valve on the side of the valve element.

  An annular channel 329 with undercut configuration, which is formed in the valve support 306 and to which the bypass channel 321 is connected, connects radially offset with respect to the appendix 315. As shown in Figures 27 and 28, a first section of the bypass channel 321 widens continuously radially starting at the annular channel 329, and a second section which constitutes the bypass channel 321b and whose cross sectional profile remains constant over

  its entire length, connects to the first.

  In another exemplary embodiment shown in Figure 29, the components which coincide with those of the exemplary embodiment shown in Figures 27 and 28 are designated by the same reference numerals so that it is necessary to refer to

  their description, examples of implementation

  shown in Figures 27 and 28.

  Unlike Figures 27 and 28, the valve element 333 of Figure 29 has on its two end faces 327 frustoconical appendages 330a, 330b. This configuration forms a centering appendage both on the valve seat 317 and for the support of the compression spring 319. Arranging a frustoconical appendage 330a, 330b on each of the two sides also allows mounting without orientation in position, which avoids any assembly fault for the valve element 333. Another difference concerns the bypass channel 331 in which the first section, the bypass channel 331a, widens in cross section over its entire length and is followed by a second section which constitutes the flow channel 331b and there and in which the increase in the cross section on

  the whole of its length is much shorter.

  Figure 30 represents a view according to the arrow of Figure 29 which represents the configuration of the bypass channel 331 as well as of the receiver 332 of the valve element 333. According to a method which makes it possible to achieve a shape favorable to flow, the individual segments 331a, 331b of the flow channel are in the form of arcs of circles in cross section. This configuration is chosen in such a way that the cross section of the flow channel increases continuously as the stroke of the valve element, that is to say its open state, increases. Figure 30 also clearly shows the force exerted on the valve member in the direction of the arrow because the bypass of the valve member takes place on a

  single side bypass 331.

  Figures 31 and 32 show flow characteristics of damping devices. In the graphs, the volume flow is plotted on the abscissa and the pressure loss on the ordinate. Figure 31 shows the plot of the characteristic for a damping device according to the invention in which the valve element already has a stable state from the opening phase, that is to say that this structure avoids the appearance of an unfavorable "opening beat" of the valve element. The outline of the characteristic of a conventional damping device is shown in Figure 32. In addition to a significantly higher pressure loss, the conventional damping device suffers from the disadvantage of a "beat of clear opening in the opening phase of the valve element which leads to development

unfavorable noise.

  The claims appended to this application

  are wording proposals, without prejudice to obtaining continuous patent protection. The plaintiff reserves the right to claim still other particularities which are not

  so far set out only in the description and / or the

drawings.

  References used in the sub-

  claims relate to the continuation of the

  development of the subject of the claim

  main thanks to the peculiarities of the

  respective claims; you don't have to

  consider as a renunciation of obtaining independent protection of the object of the peculiarities of

sub-claims concerned.

  But the objects of these subclaims

  also constitute autonomous inventions, which represent an independent configuration of objects

  previous subclaims.

  The invention is also not limited to the example or

  to the examples of embodiment of the description. Well

  rather, numerous alterations and modifications are possible within the framework of the invention, in particular variants, elements and combinations and / or materials which are for example inventive by combination or transformation of the particularities or elements or process steps described in the

  general description and embodiments as well

  that the claims and contained in the drawings,

  and which lead by particulars which can be combined to a new object or to new process steps or sequences of process steps, insofar as they relate to manufacturing processes,

verification and machining.

Claims (73)

  1. Damping device, intended in particular to dampen pressure oscillations and / or pressure pulsations in a hydraulic operating system, comprising at least one master cylinder, a slave cylinder and a pressure line which connects them, in which the damping device which is connected to a component of the operating system and can be stressed by a pressure fluid comprises a casing (2) including at least one element, characterized in that the volume of the casing can be increased in opposition   to the effect of an energy accumulator (28).   2. Damping device by means of which pressure oscillations or pressure pulsations of a hydraulic operating system of a clutch release coupling of a vehicle can be damped or eliminated, in which the operating system comprises for example a coupling pedal, maneuverable by the driver, which cooperates with a master cylinder, the latter is connected by a pressure line to a slave cylinder which acts on a release stop of the clutch release and the damping device which is connected to a component of the operating system and can be stressed by a pressurized fluid comprises a casing which is in one piece or consists of at least two components and in the space of which a closure body (13 ) is arranged to slide, characterized in that the sealingly mounted closure body which rests on an elastic element (28) is biased directly t or indirectly by a pressurized fluid. 3. Device (la) according to claim 1 or claim 2, characterized in that a damping characteristic of the damping device can be influenced by geometrically configuring the closure body and by specifying the elastic element (28) at the means of a constant   defined elastic or defined elastic rigidity.   4. Device according to any one of   previous claims, characterized in that   a piston (8) or an annular piston (25, 37) is arranged as a closure body in the damping device. 5. Device according to any one of   previous claims, characterized in that   at least one disc spring (12, 28) on which the piston (8) or the annular piston rests   elastically is provided as an elastic element.   6. Device according to any one of previous claims,   characterized in that a helical spring (43) on which the annular piston (37) rests is provided as an element elastic.   7. Device according to any one of   previous claims characterized in that   the coil spring (43) has at least two spring turns.   8. Device according to any one of   previous claims, characterized in that   the disc spring (12) is centered on a cylindrical appendage of the piston and rests on a front wall or on a space limitation internal (7).   9. Device according to any one of   previous claims, characterized in that   the disc springs are arranged in the same or alternating directions to form a pack of disc springs on which the piston (8) or the   annular piston (25) bears elastically.   10. Device according to any one of   previous claims, characterized in that   the internal space (7) for receiving the piston is provided, in the casing configured in one piece, in a part offset from the line (21) of   fluid pressure fluid under pressure.   11. Device according to any one of   previous claims, characterized in that   the internal space (7) is closed by a cover (9) which at the same time constitutes the end stop of piston stroke.   12. Device according to any one of   previous claims, characterized in that   the piston comprises, to ensure its sealing, an annular groove (18) or a peripheral recess formed on the front side to receive a tight seal (14) which rests tightly on   the outer side on a wall of the internal space.   13. Device according to any one of   previous claims, characterized in that   a plug-in element (23a, 23b, 23c) is introduced in positive engagement into an element   receiver (22a, 22b, 22c) to form a housing.   14. Device according to any one of   previous claims, characterized in that   the plug-in element is fixed in position on the receiving element by means of a sleeve (24a, 24b, 24c).   15. Device according to any one of   previous claims, characterized by   a direct attachment in positive engagement between the receiving element (22d) and the plug-in element (23d). 16. Device according to any one of   previous claims, characterized in that   the annular circular internal space for receiving the annular piston, arranged concentrically with a line of pressurized fluid in the casing or in its receiving element is connected to the line (21, 40) of pressurized fluid by means a bypass channel (36, 41).   17. Device according to any one of   previous claims, characterized in that   the annular piston projecting, on the side facing the bypass channel, a seal (32) which rests sealingly on the appendage (27a), by an inner dynamic sealing lip, and on a wall which surrounds the annular piston with a dynamic sealing lip outside.   18. Device according to any one of   previous claims, characterized in that   the annular piston (25) is supported   damped on at least one disc spring (28).   19. Device according to any one of   previous claims, characterized in that   the annular piston which rests on a helical spring (43) on the side opposite the circular annular internal space (30b) is arranged in this space internal.   20. Device according to any one of   previous claims, characterized in that   the damping device (the) comprises a throttle valve (54).   21. Device according to any one of   previous claims, characterized in that   it is a disc (55) arranged between the receiving element and the plug-in element which is provided as throttle valve (54).   22. Device according to any one of   previous claims, characterized by   a spring by means of which the first throttle valve (54) is biased towards a throttling position.   23. Device according to any one of   previous claims, characterized in that   the damping device (la) is arranged in the pressure line which connects the master cylinder to the slave cylinder.   24. Device according to any one of   previous claims, characterized in that   the damping device (la) is combined with a master cylinder (50).   25. Device according to any one of   previous claims, characterized in that   the damping device (la) is arranged in the slave cylinder (51), either directly or in its pressure tap (52).   26. Device according to any one of   previous claims, characterized in that   the damping device (ld) comprises two devices arranged offset relative to each other whose damping characteristics are different. 27. Device for damping pressure oscillations in hydraulic systems, in particular in a hydraulic system for operating a vehicle clutch coupling, which comprises: a master cylinder to be maneuvered which is connected by a pressure line to a slave cylinder (109) which activates a declutching coupling, and in which the pressure line or any component of the hydraulic operating system is connected to a damping member whose casing (102a to 102f) comprises a membrane (110a a 110e) to which a pressurized fluid can be applied, characterized in that the membrane structured to act as a cover is attached in positive engagement to the plastic casing and thus closes so seals a housing chamber.   28. Device according to any one of   previous claims, characterized in that   the jar configuration membrane surrounds by a collar (111) a cylindrical appendage (112) of the casing. 29. Device according to any one of   previous claims, characterized in that   an end part (113) of the collar is applied to the rear of the appendix (112) of the housing by being folded there.   30. Device according to any one of   previous claims, characterized in that   the membrane (11Ob) is attached by means of a snap connection arranged between the flange and the housing (102b).   31. Device according to any one of   previous claims, characterized in that   a sealing ring (115a, 115b) is arranged in a peripheral groove (114) or in a recess in the casing to ensure the sealing of the membrane and in that the flange of the membrane covers the ring   in the mounted position.   32. Device according to any one of   previous claims, characterized by   a housing (102d) which is provided with two membranes   (llOd) configured in pots and diametrically opposite.   33. Device according to any one of   previous claims, characterized by   a membrane (110c, 110d) which is provided with a domed bottom (118, 120) of casing which has a   bulge towards the casing or towards the outside.   34. Device according to any one of   previous claims, characterized by   a casing (102a to 102d) which is provided with two   radially oriented pipe fittings (104, 105).   35. Device according to any one of   previous claims, characterized in that   the casing (102e) is provided with two pipe fittings (104, 105) oriented parallel between   them and perpendicular to the membrane.   36. Device according to any one of   previous claims, characterized in that   the pressure lines (106, 107) are connected by pluggable connections to the fittings (104, 105) of lines of the damping member. 37. Device according to any one of   previous claims, characterized by   a damping member in which the damping space (103) is in the form of a labyrinth (128).   38. Device according to any one of   previous claims, characterized by   a damping member whose casing (102a to 102e) has, connected to the membrane (110a to 110e), a flexibility defined so as to achieve a depreciation determined.   39. Device according to any one of   previous claims, characterized by a member   damping in which the diaphragm (110f) is arranged in a recess (123) of the casing, the diaphragm rests on a support, a retaining ring is arranged in front of the diaphragm and an edge situated on the casing side is folded in at least inward sections to secure these components. 40. Device according to any one of   previous claims, characterized by   a seal (115c) which is arranged in a peripheral annular groove (122) located on the front side and formed in the support and which bears under prestress on the membrane in the assembled state. 41. Device according to any one of   previous claims, characterized by   a damping member (0lla to 101f) which is connected to a component of the hydraulic operating system, for example the master cylinder (108), the slave cylinder (109) or the pressure line (106, 107), or which is integrated into one of these components. 42. Damping device for pressure oscillations or pressure pulsations in hydraulic systems, in particular in a hydraulic system for operating a clutch release coupling of a vehicle, in which the operating system comprises a master cylinder which is connected by a pressure line to a slave cylinder which activates the clutch release, the damping device which is connected to the operating system comprises a casing provided with at least one pipe connection and a membrane as well as an element retaining device which constitutes a stroke limitation for the diaphragm, characterized in that a recess (221) surrounded by an edge (222) is provided in the casing to receive the diaphragm in front of which a retaining element is fixedly in position is housed.   43. Damping device for pressure oscillations or pressure pulsations in hydraulic systems, in particular in a hydraulic system for operating a clutch release coupling of a vehicle, in which the operating system comprises a master cylinder which is connected by a pressure line to a slave cylinder which activates the clutch release, the damping device which is connected to the operating system comprises a casing provided with at least one pipe connection and a membrane as well as an element retaining element which constitutes a stroke limitation for the diaphragm, characterized by a plastic casing which is combined with a diaphragm (205b) made of spring steel and with a retaining element (206b) made of plastic or made of steel which surrounds the membrane.   44 Damping device for pressure oscillations or pressure pulsations in hydraulic systems, in particular in a hydraulic system for operating a clutch release coupling of a vehicle, in which the operating system comprises a master cylinder which is connected by a pressure line to a slave cylinder which activates the clutch release, the damping device which is connected to the operating system comprises a casing provided with at least one pipe connection and a membrane as well as an element of retainer which constitutes a stroke limitation for the diaphragm, characterized by a disc configuration housing which is integrated together with the diaphragm (205c) in a   retainer (206c) in pot configuration.   45. Device according to any one of   previous claims, characterized in that   the pipe fittings (212, 213) are arranged inside a circular external contour of the casing (202a).   46. Device according to any one of   previous claims, characterized by   an aluminum casing, preferably produced by extrusion, into which are integrated a membrane (205a) made of spring steel as well as a   metal material retainer (206a).   47. Device according to any one of   previous claims, characterized by   a retainer (206d) which has a central projection (209) which approaches the diaphragm (205d) while maintaining a dimension gap in the neutral position of the membrane.   48. Device according to any one of   previous claims, characterized by   a retaining element (206d) whose edge surrounds an outer zone of the casing and whose free end comes, in the assembled position, to be applied to the rear of an appendage (208) of the casing while being there folded inwards.   49. Device according to any one of   previous claims, characterized in that   the edge (207d) is attached in positive engagement to the cylindrical envelope surface of the housing (202) by means of a snap connection. 50. Device according to any one of   previous claims, characterized by   a material connection between the edge (207b) of   the retainer (206b) and the housing.   51. Device according to any one of   previous claims, characterized in that   a sealing ring (210) which seals on the diaphragm in the mounted position is arranged on the front side in a peripheral groove (211) of the casing to ensure sealing of the membrane.   52. Device according to any one of   previous claims, characterized in that   a sealing ring (214) which presses in a sealed manner under prestress in the position mounted on the inner side on the edge is arranged in an annular groove (215) of the casing between the casing and   the edge of the retainer (206e).   53. Device according to any one of   previous claims, characterized in that   a retaining element (206f) with a disc configuration with a conical outer contour, which is arranged in a corresponding recess (216) of the casing and which is connected to the casing in the position mounted by material in the area of the bearing surface defined in   the recess is provided to hold the membrane.   54. Device according to any one of   previous claims, characterized by   a casing in which two membranes (205f) are arranged at a distance from one another and parallel to each other, each of which an element of   retainer (206f) is associated on the outside.   55. Device according to any one of   previous claims, characterized by   a casing whose pipe connections (212, 213) are oriented perpendicular to the membrane (205c).   56. Device according to any one of   previous claims, characterized in that   a damping space (203) of the casing which is closed laterally by the membrane is in the form of labyrinth (220).   57. Device according to any one of   previous claims, characterized in that   the damping device (201a to 201g) is integrated into one of the components of the operating hydraulic system (226), for example the master cylinder or the slave cylinder or the pipe under pressure, or connected to it.   58. Device according to any one of   previous claims, characterized in that   the membrane (205a) and the retaining element (206a) are fixed in position by folding or folding less of the edge sections.   59. Device for damping pressure oscillations and / or pressure pulsations in a hydraulic operating system of a vehicle clutch release coupling, comprising a support (306) of valves on which two elements (313, 314, 333) radially offset and elastically biased valve which each forms a valve seat (317) with the valve support (306), characterized in that the valve elements (313, 314, 333) of cylindrical configuration, associated at different directions of the pressurized fluid are guided in the valve support (306) and a bypass channel (321, 322, 331), the cross-sectional area of which increases at least partially as a function of the longitudinal extension , therefore an opening stroke of the valve element (313, 314, 333), is associated with each of the valve elements (313, 314, 333) in the valve support (306) and arranged in parallel to an axis longitudinal (325).   60. Device according to claim 59, characterized in that the valve support (306) comprises, to form the valve seat (317), a supply channel (328) whose diameter is less than that of the element (313 , 314, 333) of valve, and which comprises, projecting in an axial direction, an appendage (315, 316) on which the element (313, 314, 333) rests by a region of its front surface ( 327) which is shifted to   the interior in relation to its exterior outline.   61. Device according to claim 60, characterized in that an undercut with annular channel configuration (329) is provided in the valve support (306) offset from the appendage. (315).   62. Device according to claim 61, characterized in that the bypass channel (321, 322) is continuously enlarged, starting from the annular channel (329),   over the entire longitudinal extension.   63. Device according to claim 59, characterized in that its bypass channel (321, 322, 331) has a first section which increases more than proportional to the stroke of the valve element (313, 314, 333) and a second section which connects to the first and the cross section of which increases in proportion to the stroke of the element (313, 314, 333) of valve.   64. Device according to claim 59, characterized in that the maximum cross section of the bypass channel (321, 322, 331) is greater than the cross section of the supply channel (328) of the damping device (301).   65. Device according to claim 60, characterized in that the configuration of the supply channel (328) is in the form of a venturi on the end opposite the seat (317) valve.   66. Device according to claim 59, characterized in that the configuration in cross section of the profile   of the bypass channel is in an arc.   67. Device according to claim 59, characterized in that the valve element (313, 314, 333) has frustoconical appendages (330a, 330b) on its two front faces (327).   68. Device according to claim 60, characterized in that the appendage (315) of the valve support (306), located axially projecting, forms an oblique or conical surface characterized by the angle "a", on which s supports the front surface (324) of the element (313, 314, 333) of valve.   69. Device according to claim 59, in which the compression spring (319, 322) is centered in position on the frustoconical appendage (330b) on the side of the valve element (333) which is opposite to the valve seat (317).   70. Device according to claim 68 characterized in that the valve element (313, 314, 333) has rotational symmetry, which eliminates the need for oriented mounting. 71. Device according to claim 59, characterized in that the compression spring (319, 320) is centered on a component, associated with the valve support (306), in the casing (302, 303) which comprises for this purpose a appendage (323) whose front surface (324) constitutes a limit stop for the element (313, 314, 333) valve.   72. Device according to claim 59, characterized in that the valve element (313, 314, 333) is guided with sliding while tolerating a mounting clearance> 0.01 mm in the valve support (306).   73. Device according to claim 59, which comprises a sealing element (313, 314, 333) of steel, as well as a support (306) of plastic valve which are integrated in the housing (302, 303) made of plastic.