FR2642493A1 - 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 supporting a load, an electrostrictive or magnetostrictive actuator 4 is associated with the element 3 according to a mechanical assembly in parallel, one 4.1 of its end faces being rigidly connected to a connection part 1 or 2 and its other end face 4.2 being connected to the other part by means of a hydraulic system 8, and a sensor 5 is provided which detects 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 motor vehicle engines.

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 frequency 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 to say oscillations at frequencies below about 20 Hz, which generally appear with large amplitudes, while supporting practically without damping them high frequency oscillations, that is to say oscillations having frequencies above about 20 Hz, which generally appear only with a small amplitude, but are very troublesome because of their acoustic effect, and therefore to deviate, to a large extent, from the base or the 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

  so that one of its front faces is

  rigidly connected to a connecting part of the spring element, while its other end face is connected to the other connecting part, via a closed hydraulic system making a static decoupling, and that it is provided a sensor, which detects alternating forces, alternating accelerations or oscillatory deviations, caused by the load

  oscillating, and is connected to the actuator through

  of an amplitude and phase regulator and an amplifier, the regulation being designed in such a way that

  the actuator reduces the alternating forces, the accelerations

  alternative rations or oscillatory deviations

charging the sensor.

  According to an alternative embodiment, the sensor is coupled to the connection portion integral with a frame or a base. 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 a second aspect, the problem is solved

  according to the invention with the aid of an elastic support

  than the type indicated above, characterized in that an electrostictif or magnetostrictive actuator is associated

  to the spring element according to a mechanical mounting in

  so that one of its front faces is

  rigidly connected to a connecting part of the spring element, whereas another front face is connected to the other connection part, via a closed hydraulic system which performs a static decoupling, and is provided a sensor, which detects a characteristic parameter of displacement and position

  periodically displaced parts of the oscillating load

  such as the angular position and / or the

  rotation speed of the crankshaft of a motor vehicle

  bile- and is connected, via a calcula-

  from an amplifier to the actuator, and that in the

  calculator is memorized a program, which processes the

  output from the sensor and is established on the basis of

  the oscillation characteristic, determined in a manner

  piracy, of the charge and by means of which the signal of

  output of the computer, which loads the actuator

  of the amplifier, controls the actuator so as to reduce the alternating forces, the alternative accelerations or the oscillatory deviations, which appear in the integral connection part

a chassis or pedestal.

  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.

  In accordance with the present invention, said

  is associated with the spring element, which presents

  elasticity of the rubber and supports the oscil-

  of the elastic support proposed, according to a mechanical connection in parallel, in which case it is supported, by means of its face located opposite the load, through a closed hydraulic system, realizing

  static decoupling. It follows that the

  The actuator is fully supported by the spring element, while the actuator is loaded solely by the alternating dynamic forces superimposed on the static load: indeed such a hydraulic system carries out only. decoupling against forces acting in a static or quasi-static manner - i.e. at low

  frequency, while behaving like a legitimate link

  against high-frequency alternating forces.

  For this reason, high frequency variations of the length of the actuator directly affect the

  supporting forces acting on the connecting part

  which supports the load of the elastic support

  according to the invention, and therefore the forces

  high-frequency devices, which are caused by the oscillating load, are absorbed by the actuator,

  means of a corresponding order of the latter.

  In the support according to the invention, the

  the controller 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 alternating forces or oscillatory deviations caused by the oscillating load, and by means 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 quantity and in particular to its

  As sensors, piezoelectric elements are preferably used, otherwise it is possible to envisage

  to use sensors such as strain gauges

  metrics. We choose the mounting location of the cap-

  preferably as close as possible to the module formed by the rubber spring element and the actuator, to exclude an influence from parasitic oscillations from other excitation sources, which can not be removed by adjustment using the actuator. In order to use the advantageous effects obtainable by virtue of the invention solely in relation to a single oscillation direction, in a preferred embodiment, an actuator, with which a sensor is associated, is associated with each direction of rotation. main 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 of a tripod to

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.

  movement and position of parts, displaced by

  periodically, of the load borne by such a support, these parameters being related to the cause of the oscillations of

  the charge 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 means of tests 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; - Figure 2 shows an axial section of a practical embodiment having an integrated damping device; and - Figure 3 shows an axial section of a

  another example of practical realization.

  As shown in Figure la, an elastic support

  according to the invention comprises an element of

  elastic fate 3 and an actuator 4, which are connected

  mechanically in parallel between the connecting part

  1, loaded by the oscillating load L, and the part

  connection 2 secured to a base or frame.

  To obtain this mechanical connection in parallel

  leler, the actuator 4 is rigidly connected, by its front face 4.1 turned on the load side, to the corresponding connecting portion 1 of the spring element 3, while its opposite end face is not coupled for example at the connecting part 2, integral with the base, of the spring element 3, but which is mechanically equivalent with respect to high-frequency alternating forces, is supported on the ground of FIG. inertia 9. A sensor 5, preferably piezoelectric, is arranged to receive the alternating forces

  caused by the oscillating load L. Its output signal

  tie is processed by the connected regulator 6 and the amplifier 7 so that it moves the actuator 4, the regulation being designed so

  that the alternative forces provoked by the os-

  cillante L are absorbed by the actuator 4 without being

  transmitted to the connecting part 2, to which

coupled the sensor 5.

  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

  of which the actuator 4 modifies respectively its length

  to compensate or reduce to a large extent, permanently, the alternative forces, the

  alternate accelerations or oscillatory deviations

  which appear in the support.

  Figure 2 shows an example of how

  practice of the invention, in which the support

  elastic element further comprises a damping device

  porates. The spring element 3 made in the form of a rubber spring comprises a housing 10, which

  contains two chambers 11 and 12, the volume of which is

  natively variable and which are filled with a liquid having in particular a low viscosity. These rooms

  separated from each other by a separating wall

  13, which contains a transfer aperture 13.1 and is attached to the housing wall. The medial portion 13.2 of the partition wall 13 is held axially movable, by means of an elastic connection 13.3 and bears, via an actuator

  4 rigidly connected by its front face 4.1 to said part

  median tie, on the support 10 rigidly connected to the other

front face 4.2 of the actuator.

  In this medium, oscillations at low frequency

  The amplitude and the amplitude do not act substantially on the actuator 4 since the forces deforming the spring element 3 via the connecting part I lead only to a displacement of the liquid between the chambers 11 and 12. These oscillations

  are damped due to the flow resistance

  appearing in the transfer aperture 13.1.

  In the case of high frequency oscillations, the transfer aperture 13. 1 creates a high resistance to flow so that, since the liquid is incompressible, there is practically a rigid connection between the actuator 4 and the connection part 1 connected to the load. This is why, under the effect of variations, at high frequency, the length of

  actuator 4, which can be triggered in this

  deny by the signals produced by a sensor not represented

  adjusted and amplified, corresponding forces can be transmitted via the liquid, due to the -rigid coupling, to the connecting part

  connected to the load, said forces attenuating the

  plitudes of the alternating forces of the oscillating load at the connecting part 1, so that

  obtains the desired acoustic insulation effect.

  In the case of the exemplary embodiment

  FIGS. 3 and 3 show an elastic support, the spring element 3 is also in the form of a closing rubber spring, on the load side, a housing 10. The housing 10 is completely filled with a preferably very viscous liquid, and a face 4.1 of the actuator 4, which extends

  in the direction of the axis A of the support in the space ind

  the inner part of the housing, is fixed to the connecting portion 1 which is integral with the load and is connected on its side facing away from the housing 10, the rubber spring. The other end face 4.2 of the actuator 4 is rigidly connected to a damping disk 14, which extends in the liquid transversely to the axis A of the support, without being in contact with the housing 10. As in the case of the support of FIG. 2, also in the case of this embodiment, neither low frequency and high amplitude load variations, nor the static basic load charge the actuator 4. liquid surrounding the

  damping disk 14 provides rigid support

  against high frequency oscillations, so that axial variations in the length of the actuator 4, which are caused by a sensor not shown,

  produce, depending on the intercalated systems of

  tion and amplification, alternating forces that are applied to the load-supporting connecting part 1 and which absorb the load variations at

  high frequency when the control system is re-

  and therefore provide acoustic insulation

tick.

  Similarly, the support of FIG. 3 provides a high damping with respect to high frequency load variations, since these variations are related to axial displacements of the damping disc 14, which are braked by the liquid preferably. viscous,

which surrounds the disc.

  In principle, the embodiments

  in accordance with Figures 2 and 3 may also function

  when the device is placed upside down, in which case the connection part indicated in the figures by the reference numeral 2 supports the load and

  the connecting part 1 is supported on the chassis.

Claims (9)

  An elastic support having 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 or magnetostrictive actuator (4) is associated with the spring element (3) in a parallel mechanical arrangement so that one (4.1) of its end faces is rigidly connected to a connecting part (1 or 2) of the spring element (3), while its other end face (4.2) is connected to the other connecting part (2 or 1) by   through a closed hydraulic system (8)   static decoupling, and provision is made for a   (5), which detects alternative forces, access   alternating or oscillatory deflections, caused by the oscillating load (L), and is connected to the actuator (4) via an amplitude and phase regulator (6) and an amplifier (7). ), the regulation being designed so that the actuator (4)   reduce alternative forces, alternating accelerations   native or oscillatory deviations charging the Cape (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 1 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 feet orthogonal.   An elastic support having 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 or magnetostrictive actuator (4) is associated with the spring element (3) in a parallel mechanical arrangement so that one (4.1) of its end faces is rigidly connected to a connecting part (1 or 2) of the spring element (3), while its other end face (4.2) is connected to the other connecting part (2 or 1) by   through a closed hydraulic system (8)   static decoupling, and provision is made for a   (5 '), which detects a characteristic parameter of   displacement and position of parts, moved periodically   the oscillating load (L) - for example, the angular position and / or the rotation speed of the crankshaft of a motor vehicle - and is connected,   via a calculator (6 ') of an amplifier   (7) to the actuator (4), and that in the computer (6 ') is stored a program which processes the output signals of the sensor (5') and is established on the basis of the   oscillation characteristic, determined empirically   of the load (L) and by means of which the output signal of the computer, which charges the actuator (4) via the amplifier (16), controls the actuator so as to reduce the alternating forces. - alternate accelerations or deviations   which appear in the connecting part of the   deement (2) integral with a frame or 4'un socle.   8. Elastic support according to any one of   Claims 1 to 7, characterized in that the element   spring (3) is equipped with a damping device.   9. Elastic support according to claim 8, 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.