FR2560325A1 - SHOCK ABSORBER FOR VEHICLE SUSPENSIONS - Google Patents

Abstract

A VEHICLE SUSPENSION IS PROVIDED WITH INTELLIGENT ELECTRONIC DAMPING REGULATION, WHICH OPTIMIZES COMFORT, SAFETY AND HANDLING WITHOUT SUPPLY OF EXTERNAL ENERGY. THE ELECTRONIC DEVICE IS COMBINED WITH ONE OR MORE SENSORS, DETECTING IN PARTICULAR SUSPENSION MOVEMENTS, AND ACTS ON A SOLENOID VALVE 19 WHICH ADJUSTS THE DAMPER FLOW SECTION IN A PASSAGE 17 BETWEEN THE TWO CHAMBERS 6, 7 OF THE SHOCK ABSORBERS HYDRAULICS TELESCOPIC.

Description

The invention relates to a damping system.

  oscillations for vehicles, comprising at least one damper

  weaving between a wheel and the vehicle body, which has a working chamber intended to receive damping fluid and which a piston divides into two chamber parts which are connected

  to each other through at least one damping valve.

  Hydraulic shock absorbers are known

  copics (see for example the German patents DE-PS 26 55 705, DE-PS 27 44 301) o a working chamber is divided by a damping piston in two parts of the chamber and o this piston carries the valves - type mechanical - necessary to produce

  the amortization effort. Such a conventional shock absorber has the incon-

  its damping characteristic, adapted to the type of vehicle, is invariable and must therefore achieve a

  compromise for different walking conditions. Such amortization

  ment of the oscillations of a vehicle by telescopic shock absorbers is greatly limited in its properties during service, which is further aggravated by the fact that the damping system

  is influenced by the different load states of the vehicle.

  A method is also known for the active damping of oscillations (see for example the German patent application DE-OS 27 38 455) where the damping force can be adapted. However, this solution has the disadvantage that the depreciation losses must be compensated by an external pump. Such a system with external energy supply requires an additional hydraulic system with an external power source, so that it becomes very expensive. Many types of vehicles do not have such an additional hydraulic system and some do not even allow installation. In addition, in case of failure of this external pump, the running safety is no longer

  assured since the entire damping system is then faulty.

  Starting from this state of the art, the invention

  aims to provide a vehicle damping system with an

  variable damping, with intelligent electronic control and allows, without external energy input, to optimize comfort, safety and handling during

vehicle running.

  To this end, according to the invention, a damping system as defined at the start is characterized in that at least one of the damping valves is produced as

  a valve controlled by a suitable electronic device.

  This solution has the advantage that the damping valve can be adapted electronically to the condition of the road and the vehicle. The mechanical valves which remain and which serve as the basic damping, ensure operating safety

  in the event of a possible failure of the electronic device.

  Another advantage is that such regulation makes it possible at the same time to compensate for wear and manufacturing tolerances, as well as

  variations depending on the temperature of the damping system

  sement. According to another essential characteristic, the electronic device is attacked by at least one sensor which detects the amplitudes of movement between the wheel and the bodywork

  of the vehicle. It is possible to provide additional adaptation

  shut off the valve, and as a result of the entire damping system

  using an additional sensor to detect one or more other parameters. It can be the state of charge of the vehicle, its running state, its speed or even the

  temperature in the system for example.

  The damping system can also be achieved without problems by virtue of the fact that the values recorded on the front axle can be used as signals for the rear axle. The forecast of several sensors allows

  in addition to create a servo system with several variables.

  Another characteristic of the invention provides that the valve is arranged outside the working chamber

  of the damping device. We can then use a construct

  modular tion, allowing if necessary the subsequent application of the solution according to the invention to an existing damping system if the basic construction thereof allows it. When the principle of such a construction is applied from the start,

  it is also possible to obtain a simple assembly of the entire system.

amortization teme.

  According to another embodiment, the valve cooperates with throttle valves installed in

  the working chamber and / or in the bottom of the damping member.

  A conventional damping system can thus be made variable by the addition of the electronically controlled valve.

  Another embodiment provides the provision

  position of the valve in or near the piston. The valve is also shaped in this case so that its cross-section

  flow or damping section can be varied.

only.

  The sensor can detect the displacement of the piston and be installed inside the working cylinder, this

  which gives a compact system. The geometry of the shock absorbers

  In this case, it can advantageously be used by using a tubular capacitor as a piston displacement sensor providing the necessary measurement signals. Such a sensor can be installed in the hollow piston rod of the damping piston. According to an improvement of the invention, to obtain a servo system with several variables, at least one sensor is provided to detect a quantity such as the damping force, the displacement of the piston, its speed, its acceleration,

  the frequency of the oscillations, the temperature and so on.

  as well as to deliver measurement signals used by the device

  positive electronic to act on the valve in the desired way.

  It has proven particularly advantageous to use a valve

  adjustable with proportional action.

  Other features and advantages of the invention

  tion will emerge more clearly from the description which follows

  of several preferred embodiments but in no way limited

  tatives, as well as the accompanying drawings, in which: - Figure 1 is an axial section of a damping member comprising an electronically controlled solenoid valve;

  - Figure 2 is a similar section of an amor-

  twin-tube weaver whose principle corresponds to the damping member

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  shown in Figure 1, except that the damping fluid flows in one direction only;

  - Figure 3 is a similar section of an amor-

  twin-tube weaver, the principle of which corresponds to that of FIG. 2 and which includes a sensor integrated in the hollow piston rod; and

  - firm 4 is a similar section of an amor-

  twin-tube weaver whose principle also corresponds to that of

  Figure 2, but where the solenoid valve is installed on the side.

  Figure 1 schematically shows a damping member which essentially consists of a body 1, attached

  by a fixing device 2 to a guide member not shown

  felt from a vehicle wheel, and from a piston rod 3 which is

  attached by a fastening device 4 to the vehicle body-

  cule. The damping piston 8, integral with the piston rod 3, divides the interior of the working cylinder 5 into a

  upper work 6 and a lower work chamber 7.

  The piston 8 is fitted with a priming valve.

  compression weaving 9 and a traction or expansion damping valve 10. In the bottom 11 of the working cylinder

  an additional compression damping valve is incorporated

  12 and a non-return valve 13. The volume discharged by the piston rod 3 penetrates through orifices 14 in a chamber

compensation 15.

  The annular space 16 located outside the compensation chamber 15 communicates through channels 17 and 18 with the upper working chamber 6 and the

  compensation 15, the latter communicating through the ori-

  fices 14 and the non-return valve 13 with the lower working chamber 7. On the communication between the annular space 16 and the lower chamber 7 can act, in the channel 17, by an extension 20 of its frame, a damping solenoid valve 19 electronically controlled. This consists of a movable frame 21 with the extension 20, a coil 22, a spring 31 and connections 23. Depending on the electrical excitation of its coil, this solenoid valve more or less closes the channel 17 by the extension 20 of its frame, thus allowing a circulation of variable damping liquid. The solenoid valve 19 is mounted in a

  housing 24 and can be immersed in the damping fluid.

  The damping solenoid valve 19 is ordered

  by the electronic device (not shown) through the con-

  lnexions 23 and depending on the parameters noted, s which makes it possible to obtain a determined damping characteristic, depending on the position occupied by the extension 20 of the armature in channel 17, therefore according to the flow section which remains in

this channel.

  The upper part 27 of the control chamber

  pensetion 15 can be filled with a gaseous fluid, which can be pressurized or not, according to needs and functions

  Ensure by the damping device.

  FIG. 2 shows an exemplary embodiment, the principle of which corresponds to that of FIG. 1, maia whose piston 8 carries a scuplet uu'e stirapse valve 25 and whose bottom It is also only for a non-return valve 26, of norte that the fude aortisament can circulate only in one s: ns. More pri t. Fluid circulates from the upper working chamber $ 5 through channel 18 and the annular space 16, channel 17. in front of the damping solenoid valve 19, then in the working chamber infUrienra 7. Fluid circulation in

  nose cushioning element Cat important because proper regulation-

  In this case, the amortization is carried out exclusively by

  the variation of the flow section by means of the solenoid valve 19.

  The equalization chamber 15 can be filled in its upper part.

  27 with a gaseous fluid, which may or may not be under pressure,

  according to the needs and functions to be accomplished.

  FIG. 3 shows an exemplary embodiment, the principle of which corresponds to that of FIG. 2, except that the piston rod 3 has an internal volume 28 in which a sensor 29 is housed. By the connections 30, this sensor applies

  the parameters measured by him at the electronic device,

  in turn mandating the damping solenoid valve 19 by the con-

  connections 23. The sensor 29 can be made in the manner of a conden-

  tubular sator whose tubular parts form a capacitive half-bridge.

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  FIG. 4 also shows an exemplary embodiment, the principle of which corresponds to that of FIG. 2, except that the damping solenoid valve 19 is installed close to the longitudinal axis of the member and that the latter does not include any tubular space 16 around the compensation chamber 15. The channel 17, on which the solenoid valve 19 acts, in this case establishes communication between the upper working chamber 6 and the compensation chamber 15. The latter communicates below by the orifices 14 and the non-return valve 26 with the

  lower work 7. The constitution of the priming solenoid valve

  weaving 19 itself corresponds to that of the preceding examples.

  List of references 1 - Body 2 - Fixing device 3 - Piston rod 4 - Fixing device - Working cylinder 6 - Upper working chamber 7 - Lower working chamber 8 - Damping piston 9 - Damping valve of compression - Traction or rebound damping valve 11- Bottom 12 - Compression damping valve 13 - Non-return valve 14 - Drilling Compensation chamber 16 - Annular space 17 - Channels 18 - Channels 19 Damping valve - Extension d armature 21 - Armature 22 Coil 23 - Connections 24 - Amature housing - Non-return valve 26 Non-return valve 27 - Upper part of the compensation chamber 28 - Hollow interior 29 - Sensor - Connections 31 - Spring

Claims (8)

  1. A vibration damping system for vehicles, comprising at least one damping member between a wheel and the body of the vehicle, which has a working chamber intended to receive damping fluid and which a piston shares in two parts of the following chamber are connected one   to the other through at least one damping valve, characteristic   laughed in that at least one of the damping valves is   realized as a valve (19) controlled by an electro- adapted picnic.   2. System according to claim 1, characterized in that the electronic device is attacked by at least one sensor detecting the amplitudes of movement between the wheel and the vehicle body.   3. System according to claim 1 or 2, charac-   terized in that the valve (19) is arranged outside the cylinder   working (5) of the damping member.   4. System according to claim 3, characterized in that the valve (19) cooperates with throttle valves (9, 10) installed in the working chamber and with valves (12,13)   installed in the bottom of the working cylinder.   5. System according to claim I or 2, charac-   terized in that the valve (19) is arranged in the piston (8) or close to it.   6. System according to any one of the claims.   previous cations, characterized in that it comprises, as a sensor, a sensor (29) detecting the movement of the piston (8)   and installed inside the working cylinder (5).   7. System according to any one of the claims.   previous cations, characterized in that it comprises at least one   sensor to detect a quantity such as the damping force   ment, the displacement of the piston (8), its speed, its acceleration, the frequency of the oscillations between the wheel and the bodywork, the temperature and so on, as well as to deliver measurement signals used by the electronic device to act on the damping valve (19).   8. System according to any one of the claims.   cations 1 to 7, characterized in that the valve (19) is a valve   adjustable with proportional action.