FR2642489A1 - ELASTIC SUPPORT, IN PARTICULAR SUPPORT FOR MOTOR VEHICLE AUTOMOBILE - Google Patents

Abstract

In this support comprising a spring element 3 located between two connection parts 1, 2 and supporting a load, an electrostrictive or magnetostrictive actuator 4 is associated with the element 3 according to a mechanical assembly in parallel, and a sensor 5 is provided. detecting alternating forces or accelerations or oscillatory deviations, caused by the load, and connected to the actuator 4 by means of an amplitude and phase regulator 6 and an amplifier 7. Application in particular to supports for motors of motor vehicles.

Description

The invention relates to a resilient support

  carrying a spring element having the elasticity of the

  rubber, which is arranged between two connecting parts

  tion and serves to support an oscillating load, whose oscillation spectrum contains oscillations

  at low frequencies than high frequency oscillations

  quence, including a support for a motor vehicle engine

bile.

  Many different forms of reali-

  different types of motor supports. Their role is, in principle, to prevent the movements of an oscillating load from being transmitted to the base or

  chassis carrying this load, which is realized from different

  different ways and with varying success with the different embodiments of the supports. So

  than before, we mainly used pure

  rubber ports, with which the amplitudes of oscillations triggered were annihilated simply under the effect of the internal damping of the rubber padding used, it is nowadays preferred to use supports in which damping devices of the type described by example in the German patent 34 07 553 in the form of what is called a hydraulic support and in the German patent 32 33 456

  in the form of what is called a medium of type

  lumétrique. In addition to isolating and attenuating vibrations, the embodiments shown in the two documents cited have the advantage of selectively treating the oscillations acting on them, and this by strongly reducing low frequency oscillations, that is, oscillations at frequencies of less than about 20 Hz, which generally appear with large amplitudes, while supporting substantially high-frequency oscillations, i.e. oscillations, without damping them. having frequencies greater than about 20 Hz, which generally appear only at a low amplitude, but are very troublesome due to their acoustic effect, and thus to a large extent away from the base or chassis. Although this acoustic decoupling satisfies

  already to very extensive requirements in

  Hydraulics and volumetric known, it has risen, because of the need for comfort, which has greatly increased

  meanwhile, the problem underlying this invention is

  to create an elastic support which optimizes

  the transmission of high frequency oscillations, including acoustically troublesome, by means of a flexible adaptation and active control of their resulting forces of its springs, which support the oscillating load. The solution of this problem is of particular importance for the support system of

  motor vehicle drive motors.

  According to a first aspect, this problem is solved

  according to the invention by means of an elastic support

  of the type indicated above, characterized in that an electrostictive or magnetostrictive actuator is associated

  to the spring element according to a mechanical mounting in

  a sensor, which detects alternating forces, alternating accelerations or oscillatory deviations caused by the oscillating load, and is connected to the actuator via an amplitude regulator and phase

  and an amplifier, the regulation being designed from

  that the actuator reduces the alternating forces,

  alternative accelerations or os-

balloons charging the sensor.

  According to an alternative embodiment, the sensor is coupled to the integral connection portion of a

chassis or pedestal.

  According to an alternative embodiment, the sensor

is a piezoelectric sensor.

  According to an alternative embodiment, the sensor

  is arranged in the manner of an extensometric gauge.

  According to an alternative embodiment, the support comprises actuators and sensors associated with the

  main oscillation directions of the oscil-

sustained lante.

  According to an alternative embodiment, the support contains three actuators and sensors, arranged under the

  shaped like a tripod with orthogonal feet.

  According to an alternative embodiment, the actuator and the sensor are combined to form a module consisting of piezoelectric elements in the form of disks, which are stacked in the direction of the axis of the support or

  in the direction of oscillation of the load, the

  piezoelectric actuator elements are connected

  electrically in parallel and being electrically isolated

  of the piezoelectric element of the sensor.

  According to a second aspect, the problem is solved

  according to the invention by means of an elastic support

  of the type indicated above, characterized in that an electrostictive or magnetostrictive actuator is associated in parallel mechanical arrangement with the spring element, and a sensor is provided which detects a characteristic displacement parameter. and position

  periodically displaced parts of the oscillating load

  such as the angular position or the

  rotational speed of the crankshaft of a motor vehicle engine- and is connected, via a computer and an amplifier, to the actuator, and that in the computer is stored a program, which processes the signals sensor output and is established on the basis of the oscillation characteristic, determined from

  empirically, of the load and by means of which the

  output of the calculator, which loads the actuator

  through the amplifier, controls the

  to reduce alternative forces,

  alternate accelerations or oscillatory deviations

  which appear in the connection part

  secured to a frame or a base.

  According to a variant, the spring element is

  equipped with a damping device.

  According to a variant, the spring element is

  arranged in the form of a so-called

  hydraulic or a type of volumetric support, known per se. According to the invention, it is proposed,

  to solve the problem, to use what we

  shovel of electrostrictive or magnetostrictive actuators

  tive. Such actuators are known per se and, in general, it has already been proposed to use them as adjusting members in machine tools and precision machining machines. They possess the advantageous property that their axial length varies as a function of the voltage applied to them or of the current flowing through them, so that with the aid of these actuators it is possible to

  convert electrical signals directly into

  mechanical viations. In the context of this invention

  It is preferred to use electrostrictive actuators

  which are based on the known piezoelectric principle. In the support according to the invention, such an actuator is connected, for its control, to a sensor, which provides, in connection with a control device

  in a first preferred embodiment of the invention

  and in conjunction with a calculator in a se-

  conde embodiment, control signals, which correspond to the alternative forces. or oscillatory deviations caused by the oscillating load, and the help of which the axial length of the actuator is

  permanently modified so that the said forces

  ternative or oscillatory deviations are at least partially compensated and annihilated and therefore

  are generally transmitted in a highly

from the base to the frame.

  In this way, the actuator absorbs

  high-frequency and low-amplitude acoustic oscillations, while low-level oscillations

  frequency and amplitude are supported and possibly

  naturally damped by the spring element. Due

  small amplitudes of acoustic vibrations disturbances

  generally only a few

  tenths of a millimeter, the modifications, which are

  Readable with the same order of magnitude, lengths of available actuators are sufficient for effective isolation vis-à-vis the sound transmitted by the structure. In the first preferred embodiment, indicated above, of the present invention the

  alternative forces or oscillatory deviations pro-

  voiced by the oscillating load are detected directly

  by electrical sensors - in particular integrated into the support - in the form of

  force or displacement, the output signal of which

  command the actuator via a

  regulation known per se and an amplifier. The provision

  regulator equipped with the amplifier, the

  neur and sensor forms a closed regulating circuit,

  wherein the actuator acts as a feedback device

  setting and the sensor as a transmitter. Alternating forces or oscillatory deflections, which charge the sensor, penetrate in the form of a parasitic magnitude

  in this regulation circuit, the actual value

  the parasitic magnitude being compared with a predetermined setpoint -in particular "zero" -and the adjusting member is actuated to bring the actual value closer to this setpoint, which leads to a reduction of the parasitic magnitude and in particular to its "cancellation".

  As electrical sensors, we use

  interference of piezoelectric elements; otherwise, we can

  look to use sensors such as gauges

strain.

  We choose the mounting location of the cap-

  preferably as close to the module as possible

  formed by the rubber spring element and the action

  in order to exclude an influence from oscilla-

  interference from other excitation sources, which can not be eliminated by adjustment with the aid of

  the actuator. In a particular embodiment

  advantageously, the actuator and the sensor are united

  to form a module consisting of piezo elements

  disc-shaped electric electrodes, which are stacked in the direction of the axis of the carrier or in the direction of oscillation of the load, the piezoelectric elements

  actuator being connected electrically in parallel

  electrically isolated and isolated from the piezoelectric element

electric sensor.

  In order to use the advantageous effects

  obtained by means of the invention, not only by

  port with a single direction of oscillation, in a preferred embodiment, an actuator, which is associated with a sensor, is associated with each principal direction of oscillation of the load, which is supported by the support according to the invention. Preferably, the actuators and the sensors are arranged in the form

a tripod with orthogonal feet.

  In the second embodiment, indicated above, of the present invention, there is provided an elastic support, which uses the indicated advantages of actuators and in which a transmitter is used as sensor which detects characteristic parameters of displacement and position of parts, displaced periodically, of the load borne by such a support, these parameters being related to the cause of the oscillations of

  load. according to a direct or indirect relationship.

  When it comes to the support of a motor vehicle engine

  mobile, a suitable transmitter can detect for example the angular position and the speed of rotation of the crankshaft. The signal delivered by the transmitter is sent to a computer, which is connected to the actuator by

  via an amplifier.

  The computer then controls the actuator

  function of the detected phase signal (for example the posi-

  angle of the crankshaft) in accordance with a

  determined by testing on the basis of the

  oscillation of the charge and memorized, so

  that alternative forces or oscillatory deviations -

  especially at high frequency- triggered in the support

  can be largely compensated and absorbed

  quiet because. It may also be advantageous to provide actuators in the main oscillation directions

  of the system, in particular so that they form a

foot orthogonal feet.

  In all the embodiments of the

  elastic port according to the invention, the element of resistance

  the fate used preferably comprises an amorphous device

  weaver, which is such that the spring element is arranged not in the form of a pure rubber support, but in the form of a hydraulic support or a volumetric support of the type indicated above,

known in itself.

  Other features and benefits of the

  present invention will emerge from the description given

  hereinafter referenced to the accompanying drawings, on the

  which: - Figure la shows a representation of principle of an exemplary embodiment of the first preferred embodiment of the elastic support according to the invention, the control is adjusted by means of an actuator;

  FIG. 1b shows a representation of

  corresponding example embodiment of the second embodiment indicated above; FIG. 2 represents an axial section of an exemplary practical embodiment; and - Figure 3 shows, according to a representation

  schematic, a module that can be used in the first

  first embodiment and wherein an actuator

  and a sensor are advantageously combined.

  As shown in Figure la, in an elastic support according to the invention, a spring element

  3 and an actuator 4 are connected mechanically.

  in series between the connecting portion 1 loaded by the oscillating load L and the connecting portion 2 integral with a frame or a base. The sensor 5 is

  mechanically coupled at the connecting part

  2 and its output signal is dealt with by the Regu-

  connected transmitter 6 and the amplifier, which de-

  triggers a movement of the actuator 4, the control

  being designed so that the alternative forces pro-

  voiced by the oscillating load L are absorbed by

  actuator 4 without being transmitted to the

  cord 2, to which the sensor is coupled.

  FIG. 1b represents, according to a representation

  corresponding schematic representation, an elastic support of the second embodiment according to the invention,

  including the parallel mechanical connection of a

  spring 3 and an actuator 4 and in which a transmitter 5 ', which determines

  the phase position and rotation speed of a

  periodically moved from the load L (for example the crankshaft of a motor vehicle engine) and sends it to a computer 6 '. The calculator 6 'command

  then, through the amplifier 7, the

  4 based on the sensor signal, on the basis of a program which is empirically established and stored in it and associates with each state of oscillation of the load L, the control voltage of the actuator, by means of which the actuator 4 modifies respectively its axial length so as to compensate or reduce to a large extent, permanently, the alternating forces,

  alternate accelerations or oscillatory deviations

  which appear in the support.

  FIG. 2 shows the invention in the case of the embodiment of a rubber support

  simple for motor. Actuator 4 carries on its upper surface

  the connecting part i to be connected to the motor and is supported, by its underside, on an intermediate element 3.1 vulcanized to the rubber spring element 3. The opposite face of

  the rubber spring element 3 is joined together by vul-

  cannulation to intercalary element 3.2, which forms, with

  the connecting part 2 secured to the frame, a module

rigid dule.

  As the specialist can deduce from the

  2, Parts 3, 3.1 and 3.2 may be replaced

  advantageously by what is called a hydrau-

  lique (for example according to the German patent

  37 07 553) or by what is called a support of the type

  lummetric (for example according to German Patent 32 33 456), which makes it possible to use in addition

  the selective damping focus of such a medium.

  While FIG. 2 shows the arrangement and the type of the sensor, FIG. 3 shows a combination, particularly advantageous in the context of the present invention in the embodiment of FIG. 1a, including an actuator 4 formed by the meeting of FIG. piezoelectric elements in the form of disks, and a sensor 5 also constituted by a piezoelectric element in the form of a disk, the actuator and the sensor being united

  in the form of a compact module. The piezo elements

  disk-shaped electric form a coaxial stack, the piezoelectric elements of the actuator 4

  being electrically connected in parallel and being sepa-

  electrically of the piezoelectric element of the

  5 by an insulating layer 8. The actuator 4 and the sensor 5 of this module form, with the regulator 6 and the amplifier 7 in an elastic support according to the invention of the type explained above, a circuit of

Closed regulation.

1l

Claims (10)

  1. Elastic support comprising a spring element (3) having the elasticity of the rubber, which is arranged between two connection parts (1, 2) and serves to support an oscillating load (L), whose spectra of oscillations contains both low-frequency and high-frequency oscillations,   including support for motor vehicle engine, car   characterized in that an electrostic-   tostrictive (4) is associated with the spring element (3).   a mechanical assembly in parallel, and that a sensor (5) is provided which detects the alternating forces,   alternative accelerations or oscillatory deviations   res, caused by the oscillating load (L), and is   corded to the actuator (4) via a regula-   amplitude and phase transmitter (6) and an amplifier   (7), the regulation being designed in such a way that the   neur (4) reduces alternative forces, accelerates   alternatives or the oscillatory deviations the sensor (5). -   2. Elastic support according to claim 1, characterized in that the sensor (5) is coupled to the connecting portion (2) integral with a frame or a base.   3. Elastic support according to one of the claims   1 or 2, characterized in that the sensor (5) is a piezoelectric sensor.   4. Elastic support according to one of the claims   1 or 2, characterized in that the sensor (5) is   arranged in the manner of an extensometric gauge.   5. Elastic support according to any one of   claims i to 4, characterized in that it comprises   actuators (4) and sensors (5) associated with the di-   main oscillations of the oscillating load sustained lante (L).   6. Elastic support according to claim 5, characterized in that it contains three actuators (4) and sensors (5), arranged in the form of a tripod with orthogonal feet. 7. Elastic support according to any one of   Claims 1 to 6, characterized in that the actuator   (4) and the sensor (5) are combined to form a module consisting of disk-shaped piezoelectric elements which are stacked in the direction of the axis (A) of the support or in the direction of oscillation of the load. (L), the piezoelectric elements of the actuator (4) being electrically connected in parallel and electrically isolated from the piezoelectric element of the sensor (5).   8. Elastic support comprising a spring element (3) having the elasticity of the rubber, which is arranged between two connecting parts (1, 2) and serves to support an oscillating load (L), the   oscillation spectrum contains oscilla-   at low frequencies than high frequency oscillations   quence, including a support for a motor vehicle engine   bile, characterized in that an electrostictive actuator   or magnetostrictive (4) is associated, according to a meta-   in parallel with the spring element (3), and that a sensor (5 ') is provided, which detects a characteristic parameter of displacement and position of parts,   moved periodically, from the oscillating load (L) -   like for example the angular position or the speed of   rotation of the crankshaft of a motor vehicle engine   bile- and is connected, via a calcula-   (6 ') and an amplifier (7), to the actuator (4),   and that in the computer (6 ') is stored a   which processes the output signals of the sensor (5 ') and is established on the basis of the empirically determined oscillation characteristic of the   charge (L) and by means of which the output signal of the   culator, which charges the actuator (4) via the amplifier (7), controls the actuator so as to reduce the alternating forces, the alternating accelerations or the oscillatory deviations, which appear in the connection (2) solidaire a chassis or pedestal.   9. Elastic support according to any one of   Claims 1 to 8, characterized in that the element of   spring (3) is equipped with a damping device.   10. Elastic support according to claim 9, characterized in that the spring element (3) is arranged in the form of a so-called hydraulic support   or a volumetric type support, known per se.