FR2812052A1 - Automobile wheel-chassis articulation connection comprises two complementary bodies, connected by elastomer mass, one fixed to wheel support part and other to chassis - Google Patents

Abstract

The articulation comprises a two complementary bodies (10a,10b). The body is composed of outer and inner steel frames connected by an elastomer mass. The outer frame has an axial stop collar fitted at the time fitting the outer tube (40) in the bore (43) and the fitting of the inner tube (50) in the inner bore. A solenoid (60) is placed in a housing (15) of the inner frame and an electrical supply wire (61) is passed through a passage hole (17) at the bottom of the housing.

Description

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  ARTICULATION FOR THE WHEEL CONNECTION SYSTEM

CH SSIS "OF A MOTOR VEHICLE

  The present invention relates to the field of wheel-chassis connections for motor vehicles, and more particularly the joints provided between the triangles.

  or the suspension arms, and the engine subframe or chassis.

  By way of example, French patent FR2720036 describes a suspension system comprising an upper triangle consisting of a transverse arm in the vertical plane of the axle and an extension perpendicular to the arm extending rearward along the longitudinal axis of articulation of the triangle. The transverse arm passes and struggles under the stretcher. The suspension triangles are articulated to a cradle fixed to the vehicle body under the stretchers by elastic supports. The joints have a stiffness defined by the choice of materials. Generally, for the connection between the front suspension triangle and the engine cradle, the front joint has a stiffness more

  important than that of the rear joint.

  For rear suspensions, provision is made in the prior art for joints ensuring the connection between the suspension arm supporting the wheel, and the chassis, the suspension arms sometimes being connected by

a deformable cross member.

  The problem that arises is that of the impact of these joints on the dynamic behavior of the vehicle. It is difficult to optimize the characteristics of the joints of the state of the art for all situations, in particular for

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  meet both the demands of fast driving

  on a road in good condition, and driving at slow speed.

  To remedy this drawback, the invention relates, in its most general sense, to a hinge for the "chassis wheel" connection system of a motor vehicle comprising a first part capable of being secured to a wheel support part, and a second part capable of being linked to the chassis, as well as an elastic material interposed between said two parts, characterized in that the elastic material

  comprises means having an adjustable viscosity.

  Such a joint has the particularity of being able to change rigidity as a function of stresses coming from the ground or a request from the driver. The behavior can be in two states ("flexible" or "hard"). In the "flexible" state, the behavior of the joint is that of a conventional joint, the filtering of which therefore favors comfort. In the "hard" state, corresponding to a sporty driving for example, we will favor behavior. Between these two positions a control law can vary the stiffness or the damping. The invention will apply more particularly to a rear articulation of the front triangle. It can also be used on the arms pulled in front traction

  and as a deformable cross joint.

  Advantageously, said means having an adjustable stiffness consists of at least one chamber provided in said elastic material, and containing a

adjustable viscosity fluid.

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  According to a preferred embodiment, said

  adjustable stiffness fluid is a magneto-

  rheological. The particularity of the joint according to this embodiment is to use a "controllable fluid" which will change viscosity during the application of a

magnetic field.

  It is constructed so that by default

  operation identical to a traditional joint.

  In the event of failure of the active system, the behavior will be that of a flexible articulation of hydroelastic type which will have a resonance at a fixed frequency this being

  set to the natural frequency of the basic system to be damped.

  Such an articulation is very compact and of relatively simple definition. In active operation, it will see an evolution of its stiffness and its damping according to the desired programming and

this from a calculator.

  Alternatively, said chamber further comprises a partial filling material formed by a

  foam with non-communicating cells.

  According to a particular embodiment, one of said parts comprises a rigid external reinforcement and a rigid internal reinforcement, as well as a mass of elastomer disposed between said reinforcements. The elastomer mass has at least two working chambers for receiving a magneto-rheological fluid, the joint further comprising an electric excitation coil. Preferably, the working chambers

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  communicate with each other through channels.

  The invention also relates to a motor vehicle of the type comprising a front axle comprising a suspension triangle connected to the engine cradle by a front articulation and a rear articulation, characterized in that the rear articulation at least is an articulation comprising a first suitable part to be secured to a wheel support part, and a second part capable of being linked to the chassis, as well as an elastic material interposed between said two parts, said elastic material comprises means having an adjustable viscosity, the vehicle comprising means for controlling the viscosity of said means as a function of

predetermined parameters.

  The control means make it possible to vary the viscosity in order to change the dynamic properties of the joint as a function of predetermined parameters

  like acceleration, braking, steering wheel angle ...

  One can, for example, modify the rigidity of one side compared to another as in the case of a cornering o one would stiffen the rear articulation of the front triangle and that exterior side. So we improve

  the self-steering effect which gives an under-behavior

  turn, guarantee of safety when making a turn.

  According to a preferred embodiment, said means having an adjustable stiffness consists of at least one chamber provided in said elastic material, and containing a magneto-rheological fluid, as well as an electric coil for adjusting the viscosity of said fluid

magneto-rheological.

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  The invention also relates to a motor vehicle of the type comprising a front axle comprising a suspension arm connected to the chassis by an articulation, characterized in that said articulation comprising a first part capable of being secured to a piece of support for the wheel, and a second part capable of being linked to the chassis, as well as an elastic material interposed between said two parts. Said elastic material comprises means having an adjustable viscosity, the vehicle comprising means for controlling the viscosity of said

  medium according to predetermined parameters.

  The present invention will be better understood on

  reading the description of a non-limiting example of

  embodiment which follows, with reference to the accompanying drawings o: - Figure 1 shows an exploded view of a joint according to the invention; - Figures 2 and 3 show respectively exploded and perspective views of a half-body of the joint; - Figures 4 and 5 show views along respectively transverse and axial section planes .; The joint described in the following includes two complementary bodies (10a, 10b). In what

  follows, we will describe the mechanical structure of such a body.

  The body (10) consists of an outer frame (11) made of steel, aluminum or thermoplastic and an inner frame (12) which can also be made of steel, aluminum or thermoplastic. A mass of elastomer (13) provides the connection between the reinforcements (11, 12). This elastomer is

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  adhered to reinforcement during overmolding.

  The outer frame (12) has a flange (14) for axial stop when it is fitted into the bore (43) of the outer tube (40). The forms are not necessarily revolutionary. Only the outer shapes of the frame (11) and inner (43) of the tube

support (40) or must cooperate.

  The inner frame (12) has a housing (15) serving for positioning the solenoid (60) during mounting thereof. Thermoplastic or aluminum molding allows this groove to be produced directly during molding. For a steel construction, a recovery will be made to form a hollow groove. A protuberance made of elastomeric material (22), molded at the bottom of the groove or housing (15) of the internal frame (12) seals at the end faces of the solenoid (60). The elastomer mass has fluid chambers (20) and (21). These working chambers are arranged on either side of the link arms (23) and (24) having grooves (19a) and (19b). These grooves ensure the passage of the fluid between the working chambers (20) and (21). The section will be adjusted according to the mode to be amortized. Elastomer masses (18a) and (18b) ensure the recovery and limitation of the forces. They act as travel stops. The travel of these stops is regulated by the width of the passage (16) between the mass of elastomer (18a) and (18b) and the internal diameter of the external reinforcement (11). It should be noted that the stops

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  can be brought back into the chambers, in a material different from that of the elastomer mass (22). They can be adhered on the outside as well as inside. A hole (17) located at the bottom of the housing (15) of the interior frame (12) allows the passage of the electric wire (61)

solenoid supply (60).

  A part (26) of the mass of elastomer molded is placed on the cylindrical end of the outer frame (1). Its purpose is to ensure sealing during the final assembly in the inner bore (43) of the outer tube (40) and the fitting of the inner tube (50) in the inner bore of the body (10) . The cylindrical outer tube can be made of steel, aluminum or thermoplastic. It is he who will ensure the cohesion of the bodies (10a, 10b) during assembly. During the final assembly, this tube will be hard fitted into the element to be insulated. Chamfers (41) and (42) will facilitate the mounting of the articulation bodies (10a, 0lb). A solution corresponding to a connecting piece can be envisaged to replace the tube. In this case it is a direct mounting in the support such as a triangle connection for example. The bodies (10a, lOb) are then fitted directly into a bore of diameter

  (43) equivalent to that of the outer tube (4o).

  The cylindrical shape is not compulsory. In fact, it suffices to make the outer shape of the bore (43) compatible with that of the outer frame (11) of the

body (10).

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  The inner tube has a tubular shape.

  It will preferably be made of steel. It has at one end a beaten collar (51). The other end will flourish during the final assembly in order to immobilize the two armatures (12) of the body (10). A tight fitting may suffice. In this case, the second end does not

presents no blooming.

  The joint also includes a solenoid. It is the active element which will make it possible to polarize the magneto-rheological fluid in order to change the fluid state of the latter. It is a spool with a wire winding of a given length for a number of

calculated turns.

  The fluid consists of magnetically polarizable particles. These iron particles the size of a few microns are suspended in a

viscous medium.

  In the absence of a magnetic field the fluid behaves like a Newtonian fluid which obeys a law of linear viscosity. During the application of a magnetic field, the polarization of the particles in suspension induces the appearance of dipoles whose interactions have the effect of reorganizing the particles which were dispersed in a non-homogeneous manner initially. It is formed

  a structure in parallel chains.

  These chain structures oppose the movements of the fluid and more particularly in a direction perpendicular to the orientation of the chains. As a result, the viscosity properties are changed and

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  give rise to a force opposing displacements orthogonal to the applied field. Fluid behavior

  goes from Newtonian to viscoplastic.

  Thus, the mechanical energy required to move the chains of suspended particles will

  increase with the value of the magnetic field.

  The final assembly of such a support must be done by filling with magneto-rheological liquid under vacuum or

  in the pool. Assembly can be automatic, semi-

automatic or manual.

  To put the inner tube (50) on the assembly support, the body (10) is fitted onto the inner tube (50) until the end (25) of the frame interior (12) coincides with

  the beaten collar (51) of said tube (50).

  The next step consists of placing the solenoid (60) in the housing (15) of the interior frame (12) by passing the electrical supply wire (61) inside the through hole (17 ) located at the bottom of the

  housing (15) of said interior frame (12).

  The outer ring or tube (40) is then fitted onto the outer frame (11) of the body (10a) until the bearing face (44) of the frame (40) comes in contact with the flange

  support (14) of the outer frame (11).

  The fitting of the second body (10b) is then carried out, mounted symmetrically to the first, so as to have simultaneously the mounting of the solenoid (60) in its housing (15) and the external frame (II) in the bore.

(43) of the outer tube (40).

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  The inner tube (50) is then crimped by opening the other end

identically to the collar (51).

  Thus, the joint, assembled in immersion or under vacuum, is tight vis-à-vis the outside thanks to the presence of the sealing bead (26) located on the end of the outer frame (1). In fact when the armature (1) is fitted into the outer tube (40) and the flanges (14) are in contact with the ends

  (44) of said tube, the beads (26) are compressed.

  Another solution consists in causing the elastomer to be molded under the faces of the support flange (14) of the external frame (11). The fact that the hard fitting is carried out with the press, ensures the good resistance of the seal over time with respect to

outside of this joint.

  As regards the internal sealing, it is achieved by the presence of elastomer coming from molding and located at the bottom of the housing (15) of the solenoid (60). It is made effective when fitting the solenoid into the housings by crushing the elastomer against the ends of said solenoid. The action of keeping the seal over time with respect to the interior of the joint is ensured by crimping or

  bolting the end (51) of the inner tube (50).

  The two chambers (20, 21) are symmetrical or not with respect to the median axis in the example described. The chambers (20) and (21) are filled with fluid and during the radial deflections, the fluid will pass alternately from one chamber to the other thanks to the channels (19a) and

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  (19b). Stops (18a) and (18b), molded, ensure the limitation of travel. Pressure resistance is ensured by adjusting the thickness of the end membranes (27) which close the chambers to the outside. The proper mode of the liquid column will be adjusted by adjusting the section of the channels (19a) and (19b) as well as their length by adapting the radial thickness of the breads (23) and (24) for connection and separation

chambers (20) and (21).

  Such joints are in particular intended for the connection between the rear suspension arms

and the chassis.

  We can cause autobraking effects by modifying the stiffness of one articulation compared to another in the case of deformable crosspieces, likewise on

multi-link, see arms drawn.

  The control of the articulation can be carried out by a computer receiving information such as the angular position of the steering wheel as well as that of the acceleration and braking and delivering a command signal of the solenoid of the articulations. It is also possible to carry out a manual control allowing

  binary change all or nothing.

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Claims (8)

  1 - Joint for the "chassis wheel" connection system of a motor vehicle comprising a first part capable of being secured to a wheel support part, and a second part capable of being linked to the chassis, as well as a material elastic interposed between said two parts, characterized in that the elastic material comprises means having a viscosity adjustable.   2 - Joint for the "chassis wheel" connection system of a motor vehicle according to claim 1, characterized in that said means having an adjustable stiffness consists of at least one chamber provided in said elastic material, and   containing a body of adjustable viscosity.   3 - Joint for the "chassis wheel" connection system of a motor vehicle according to claim 2, characterized in that said body   adjustable stiffness is a magneto-rheological fluid.   4 - Joint for the "chassis wheel" connection system of a motor vehicle according to claim 2 or 3, characterized in that said chamber further comprises a partial filling material formed   by a foam with non-communicating cells.   - Joint for the "chassis wheel" connection system of a motor vehicle according to one 13 2812052   any of the preceding claims, characterized in   that one of said parts comprises a rigid external reinforcement (11) and a rigid internal reinforcement (12), as well as a mass of elastomer (13) disposed between said reinforcements (11, 12), the mass of elastomer (13) having at least two working chambers (20,21) for receiving a magneto-rheological fluid, the joint   further comprising an electric excitation coil.   6 - Joint for the "chassis wheel" connection system of a motor vehicle according to claim 5, characterized in that the working chambers (20, 21) communicate with each other by channels (19a, 19b).   7 - Motor vehicle of the type comprising a front axle comprising a suspension triangle connected to the engine cradle by a front articulation and a rear articulation, characterized in that the rear articulation at least is an articulation comprising a first part capable of being secured to a wheel support part, and a second part able to be linked to the chassis, as well as an elastic material interposed between said two parts, said elastic material comprises means having an adjustable viscosity, the vehicle comprising means for controlling the viscosity of said   medium according to predetermined parameters.   8 - Motor vehicle according to claim 7, characterized in that said means having a stiffness 14 2812052   adjustable consists of at least one chamber provided in said elastic material, and containing a magneto-rheological fluid, as well as an electric coil for   adjusting the viscosity of said magneto-rheological fluid.   9 - Motor vehicle of the type comprising a front axle comprising a suspension arm connected to the chassis by an articulation, characterized in that said articulation comprising a first part capable of being secured to a wheel support part, and a second suitable part to be linked to the chassis, as well as an elastic material interposed between said two parts, said elastic material comprises means having an adjustable viscosity, the vehicle comprising means for controlling the viscosity of said means as a function of predetermined parameters.   - Motor vehicle according to claim 9, characterized in that said means having an adjustable stiffness consists of at least one chamber provided in said elastic material, and containing a magneto-rheological fluid, as well as an electric coil for   adjusting the viscosity of said magneto-rheological fluid.