MXPA97008734A - Automotive vehicle that has a motopropulsor block equipped with a suspension with limit axis movement - Google Patents

Abstract

The present invention relates to an automotive vehicle having a chassis (3), a powerplant block (2) and a plurality of fixing devices (4, 5, 6) that support the powerplant block and dampen the relative vibratory movements between the powerplant block and the chassis parallel to a first axis (Z) substantially vertical, these fixing devices (4, 5, 6) allow the movements of the axis of the powerplant block (2) in relation to the chassis (3) parallel to the first axis ( Z) and at least parallel to a second axis (X) perpendicular to the first axis, at least one of these fixing devices called "first fixing device" (4), comprises: a rigid support arm (7) attached to the block motor (2), the support arm (7) and the chassis (3) are referred to in the following as the "first element" and the other, the "second element", an anti-vibration support (10) comprising a first reinforcement rigid (11) fixed to the arm e support (7), a second rigid reinforcement (12) fixed to the chassis (3) and an elastomer body (13) that joins the first and second reinforcements together and that supports the engine block (2) allowing the shaft movements above-mentioned relative between the power unit and the chassis, and a shaft movement limiter (14) which is able to limit the relative displacements between the power unit (2) and the chassis (3) parallel to the second axis (X), the shaft movement limiter comprises a first rigid cam (16a, 16b, 11) extending in accordance with a direction perpendicular to the second axis (X) and joined to the first element, characterized in that the shaft movement limiter (14) ) further comprises: the second (23, 23a, 37) and third (24, 24a, 38) rigid cams which each extend in accordance with a longitudinal direction parallel to the longitudinal direction of the first cam and which are attached to the second element, the second da and third cams are comprised in two planes perpendicular to the second axis (X) which are located on one side and the other of the first cam (16a, 16b, 11), and the first and second limiting rings (28, 29) have each one a winding (34) of resistant, flexible but substantially inextensible yarn, covered by an elastomer coating (33), the first limiting ring (28) being fixed to the first (16a, 16b, 11) and second cams (23) , 23a, 37) with its winding of resistant wire passed around the assembly of the first and second cams, and the second limiting ring (29) being fixed to the first (16a, 16b, 11) and third (24, 24a, 38) ) cams with their winding resistant thread passed around the assembly of the first and third lev

Description

AUTOMOTIVE VEHICLE THAT HAS A MOTORROPULSOR BLOCK EQUIPPED WITH A SUSPENSION WITH A LIMITED AXIS MOVEMENT The present invention relates to automotive vehicles comprising a powerplant equipped with a suspension with limited shaft movement. More particularly, the invention relates to automotive vehicles having a chassis, a powerplant and a plurality of fastening devices that support the motor-driven block and dampen the relative vibratory movements between the powerplant and the chassis parallel to a first With a substantially vertical axis, these fastening devices allow the movements of the motor-drive block shaft in relation to the chassis, parallel to the first axis and at least parallel to a second axis perpendicular to the first axis, at least one of these fastening devices, called " first fastening device "comprises: - a rigid support arm attached to the powerplant block, the support arm and the chassis being hereinafter referred to as the first" first element "and the other," second element ", - a support antivibratory comprising a first rigid framework fixed to the support arm, a second rigid reinforcement fi the chassis and an elastomer body that joins the first and second armatures together and supports the powerplant block allowing the relative shaft movements mentioned between the powerplant and the chassis, and a shaft movement limiter that is able to limit the relative displacements between the powerplant block and the chassis parallel to the second axis, the shaft movement limiter comprises a first rigid cam extending in accordance with a direction perpendicular to the second axis which is attached to the first element. In known vehicles of this type, for example, in the vehicle marked "CLIO", built by the RENAULT Company, the first cam is covered by a mass of solid rubber and is connected to a cavity of the support arm with which it cooperates by means of a stop to limit the axis movement of the power-train block, at least parallel to the second axis. This known method works conveniently, but has the disadvantage that, although the first cam is bumping against the wall of the support arm cavity, the significant friction generated between this cam and this wall hinders the operation of the anti-vibration support in the vertical sense.

In particular, this friction tends to directly transmit the vibratory movements between the powerplant block and the chassis of the vehicle, since the anti-vibration support is precisely provided to avoid such a transmission as much as possible. The object of the present invention is particularly to overcome this drawback. To this end, according to the invention, an automotive vehicle of the kind in question is essentially characterized in that the shaft movement limiter further comprises: the second and third rigid cams which each extend according to a longitudinal direction parallel to the longitudinal direction of the first cam and which are connected to the second element, the second and third cams are comprised in two planes perpendicular to the second axis being located on either side of the first cam, and the first and second limiting rings each have a winding of a sturdy, flexible but substantially inextensible thread, wrapped by an elastomer coating, the first limiting ring being fixed to the first and second cams with its winding of resistant thread passed around the assembly of the first and second cams, and the second being Limiter ring fixed to the first and third cams with its thread winding resist It was passed around the assembly of the first and third cams. Thanks to these arrangements, an axis movement limiter is obtained which has a relatively large voltage parallel to the second axis., so that it effectively limits the shaft movements of the powerplant parallel to this axis, presenting a very low tension in the vertical direction. These arrangements then make the shaft motion limiter do not interfere with the operation of the anti-vibration mount and therefore do not transmit the vibratory movements between the powerplant block and the vehicle chassis. In addition, the limit rings have a very good progressivity: that is, they ensure an effective but relatively smooth shaft movement limitation, without imposing any impact on the power unit block. In these preferred embodiments, in addition, the resource may optionally be used, in one and / or other of the following arrangements: the first and second limiting rings constitute a single piece of elastomer reinforced with resistant wire; the resistant thread windings of the first and second limiters ring are constituted by the same continuous wire; each limiting ring has the rigid reinforcements that are embedded in its elastomeric coating and which are interposed between the resistant wire winding of this limiting ring and each of the cams to which said limiting ring is attached; each limiting ring forms two eyelets which are frictionally embossed respectively in the two cams to which said limiting ring is attached. the cams each have a free end forming an elongated head, the elongated heads of the three cams prevent the limiting rings from detaching from said cams, the first cam is constituted by the first antivibration support frame, while the - second and third cams are attached to the chassis of the vehicle; the support arm extends from the powerplant block to an end fixed to the first support frame having an intermediate part "which is located between the powerplant block and said end and which is attached either to the first cam, either to the second and third cams; the elastomer body of the antivibration support has a bell shape "which extends from a summit joined to the first reinforcement to an annular base joined to the second reinforcement, this elastomer body partially delimiting a working chamber communicating through the intermediate of a strangulated passage with a compensation chamber delimited by an easily deformable wall, the working chamber, the compensation chamber and the throttled passage form an airtight volume filled with liquid; the powerplant block is in pendular suspension, this powerplant block extends longitudinally according to a third horizontal axis perpendicular to the second axis and is attached to the chassis by the first fixing device associated with the second and the third fixing devices, the first being and the second fastening devices substantially aligned parallel to the third axis and being fixed to the powerplant block at the points above the center of gravity level of that powerplant block, and the third fastening device being attached to the powerplant block at a point located below the powerplant. first and second fixing devices. Other features and advantages of the invention will appear in the course of the following detailed description of many of its embodiments, given by way of non-limiting example, with reference to the accompanying drawings. In the drawings: Figure 1 shows very schematically an automotive vehicle engine with pendular suspension, known per se, Figure 2 is an equally very schematic view of a prior art automotive vehicle equipped with a motor like that of the Figure 1, this Figure shows more in detail one of the fixing devices of the motor, Figure 3 is a vertical sectional view of a hydraulic anti-vibration support, known per se, belonging to the fixing device shown in Figure 2, Figure 4 is a exploded view of an engine fastening device according to an embodiment of the invention, intended to replace the prior art fastening device shown in Figure 2, Figure 5 is a cross-sectional view of a double ring elastomer limiter belonging to the fixing device of Figure 4, - Figure 6 is a sectional view according to line VI-VI of Figure 5, Figure 7 is an exploded and uncovered view for viewing a motor attachment device usable in a second embodiment of the invention.

Figure 8 is a schematic view of an engine fastening device according to still another embodiment of the invention. On the different Figures, the same references designate the identical or similar elements. The invention is preferably, but not exclusively, applied to an automotive vehicle 1 having a power unit 2 with a pendular suspension, known per se and shown in Figures 1 and 2. In such a pendular suspension, the longitudinal direction of the power-train block 2 extends generally parallel to a transverse horizontal axis Y, which is perpendicular to a horizontal axis X corresponding to the longitudinal direction of the vehicle. On the other hand, the power unit 2 is generally connected to a vehicle chassis 3 by means of three fixing devices, namely: the first and second fixing devices 4, 5, aligned parallel to the Y axis and fixed to the longitudinal ends of the powerplant block at the points above the center of gravity G of that powerplant block, and a third fixing device 6 attached to the powerplant block at a location located below that engine block.

The three fastening devices generally have anti-vibration mounts each provided with an elastomer body that joins the engine block to the chassis of the vehicle, so that it allows the movement of an axis of the propulsion block along a vertical axis Z, according to the X axis , and in rotation around the Y axis (which is translated by the movements according to the X and Z axes). In particular, the power unit 2 moves in rotation around the Y axis at each acceleration and at each deceleration. In addition, the antivibration mounts of the first and second fastening devices, 4, 5 are also provided in a manner known per se, to support the weight of the power unit 2 and to dampen the vibratory movements between the power unit block 2 and the chassis 3 along the axis Z. Finally, in order to limit the movements of the shaft of the power unit block 2, the fastening devices 4-6 include one or more shaft movement limiters. Thus, in the example shown in Figure 2, corresponding to the prior art, the first fixing device 4 comprises: a rigid support arm 7 substantially horizontal, which is generally made of molded aluminum or cast iron and which is fixed to a longitudinal end of the powerplant block 2 in the occurrence with the opposite of the gearbox 8 of the powerplant block, the support arm 7 which is traversed vertically by a channel 9 located in a substantially average position between the two ends of said arm 7 , - an anti-vibration support 10 which in all cases comprises a first rigid reinforcement 11 fixed under the support arm 7, a second rigid reinforcement 12 fixed in the chassis 3, and an elastomer body 13 joining the first and second one together armatures and supporting the powerplant block 2 allowing the aforementioned relative shaft movements between that powerplant and the chassis . and a shaft movement limiter 14 which is capable of limiting the relative displacements between the power unit block 2 and the chassis 3 parallel to the X axis, (ie, not only in translation by the X axis, but also in rotation about of the Y axis, since such rotation causes a displacement along the X and Z axes of any point of the power unit block not located on the axis of rotation). The movement limiter of the shaft 14 comprises, on the one hand, a rigid horizontal base plate 15 in the form of a horseshoe that partially surrounds the elastomer body 13 and which is fixed to the chassis 3, and on the other hand a rigid vertical cam 16 coated of solid rubber, which is attached to the base plate 15 and which extends upwards from this base plate penetrating into the cavity 9 of the support arm 7 cooperating by a stop with the side walls of this cavity. The anti-vibration support 10 can be hydraulic or not. In particular, this anti-vibration support can be of the type shown in Figure 3, known from EP-A-0 346 227, in which the elastomer body 13 has a bell shape "that extends from a summit joined to the first armature 11 to an annular base joined to the second reinforcement 12, this elastomer body partially delimiting a working chamber A communicating by means of a throttled passage 17 with a compensation chamber B delimited by an elastomer bellows 18, the work chamber A, compensation chamber B and throttled passage 17 form an airtight volume filled with liquid. Thus, the vibratory movements between the power unit block 2 and the chassis 3, and in particular the vibratory movements of relatively large amplitude (for example greater than 0.1 millimeters) and of relatively low frequency (for example less than 20 Hz), cause displacements of liquid between the chambers A and B by means of a strangulated passage 17, which causes a particularly effective damping of said vibratory movements. In addition, the chambers A and B are in general, separated in part by a valve called "decoupling" 19, which may consist for example of a rubber sheet interposed between two grids 20, 21 communicating with the chambers A, B The valve 19 absorbs vibrations of relatively low amplitude (for example, less than 0.1 millimeters) and of relatively high frequency (for example higher than 20 Hz), generated by the propulsion block 2. The fixing device 4 of the prior art which has just been described works satisfactorily globally, especially thanks to the remarkable effectiveness of the hydraulic anti-vibration support 10 that has just been described. However, although the cam 16 of the movement limiter of the shaft comes into contact with the wall of the cavity 9, the support arm 7 moves away, and in particular when the acceleration or deceleration phases of the vehicle, the important friction that exists between the cam 16 and the support arm 4 allows the vibratory movements • to be transmitted directly between the motor-drive unit 2 and the chassis 3 of the vehicle, without being attenuated by the anti-vibration support 10. To alleviate this drawback, according to a first embodiment of the invention, the first fixing device 4 is made as shown in Figure 4 in which: - the anti-vibration support 10 is identical or similar to that described above, the limiter 14 always has a base plate identical to the one described above, but the vertical cam 16 is replaced by a shorter vertical cam 16a and preferably has at its free end a head 22 forming a slight elongation, the support arm 7 is similar to the arm already described, but does not have the cavity 9, said arm 7 it has, instead, two vertical rigid cams 23, 24, which extend downwards from the lower surface of the arm 7 and each preferably having a free end provided with a head 25, 26 forming a slight elongation , the three cams 16a, 23, 24 are arranged in the same vertical plane parallel to the axis X and the free end of the cam 16a is located above the free ends of the cams 23, 24, and the cam 16a is attached to the cams 23 and 24 by means of a double limiting ring 27 of elastomer constituted by the first and second limiting rings 28, 29. These two limiting rings are each located in a horizontal plane, or more generally in a plane perpendicular to the cams 15a , 25, 26. In addition, the limiting rings can, for example, have a general oval shape extending longitudinally in the direction of the X axis between two ends each forming an eyelet delimiting an a-guide, respectively 30, 31, 32 , the cams 16a, 23, 24 being forcibly inserted each into one of these holes. As shown more in detail in Figures 5 and 6, the double limiting ring 27 has a single elastomer body 33 which is common to the first and second limiting rings 28, 29. Either way, the two limiting rings 28, 29, could be two different pieces, without therefore leaving the framework of the invention. In addition, the double limiting ring 27 is designed for a winding 34 of flexible but substantially inextensible yarn (ie less extensible than the rubber), for example of polyester yarn. This winding 34 forms two loops of thread, that is to say a first loop comprised within the first limiting ring 28 and passing to the outside of the cams 16a and 23, and a second loop comprised inside the second limiting ring 29 and which it passes on the outside of the cams 16a and 24. Each loop can for example have approximately 40 turns of thread, with the polyester threads most commonly used. Preferably, the two loops of thread are made with the same continuous polyester thread. Optionally, between the winding of the wire 34 and each cam 16a, 23, 24 a rigid reinforcement 35, metal or plastic material, can be interposed, in order to allow a good distribution of the forces between the wire winding 34 and the body 33 of elastomer. In all cases, the elastomer body 33 has the parts 36 interposed between the reinforcements 35 and the cams 16a, 23, 24, in order to obtain a good progressivity in the limitation of the shaft movements of the powerplant block, i.e. , in order to prevent the engine block from suffering violent crashes after limiting its axle movements. On the other hand, in the case of the Figure considered here, the oval shape of two limiting rings 28, 29 participates i "gually in this progressivity in the limitation of the axis movements. The double limiting ring 27 makes it possible to limit the axis movements of the power unit parallel to the X axis (ie, more in translation according to the X axis than in rotation around the Y axis, because the rotations cause movements of the power unit block especially according to the axis X) with a relatively large elastic tension, but that double limiting ring has little elastic tension parallel to the Z axis which allows not to interfere with the operation of the anti-vibration support 10. In particular, while the support arm 7 is subjected to at an effort parallel to the X axis between 500 and 2000 N, the assembly of the fixing device 4 has a weak relation between, on the one hand, its overall elastic tension Kz parallel to the Z axis and, on the other hand, its overall elastic tension Kx parallel to the X axis, this ratio being generally between 0.1 and 0.15 following the applied stress, which is an excellent value and notably less than the values obtained with prior art fixation devices such as that shown in Figure 2, or the ratio Kz / Kx being of the order of 0.2. By varying, as shown on FIG. 7, the support cams 16b, 23a, 24a, "which are respectively engaged in the double-limiting ring holes 30, 31, 32 can extend along the Y axis, in the case The two limiting rings 28, 29 are each comprised in a vertical plane parallel to the axis X. Furthermore, the three cams are not necessarily aligned, provided that the two cams attached to the support 7 are aligned parallel to the X axis and included in the respective planes perpendicular to the axis X and arranged on either side of the cam attached to the chassis 3 of the vehicle.

In the case of the Figure, as shown in Figure 7, the two rings 28, 29 of the double limiting ring 27 have non-parallel longitudinal directions forming between them an angle generally greater than 90 degrees. Finally, the three cams to which the double limiting ring is attached could be part of parts different from those described above provided that one of the cams is directly or indirectly attached to one of the arm 7 or of the chassis 3, while the others two cams, framing the first cam, are joined to the other arm 7 and the chassis 3. For example, as shown in Figure 8, one of the cams that support the double limiting ring 27 could be constituted by the first armor 11 of the anti-vibration support 10, this reinforcement 11 then preferably has an annular groove that receives the common end of the two limiting rings 28, 29. In that case, the other two cams around which the first and the second rings pass respectively limiters 28, 29, can be constituted by two rigid vertical cams 37, 38, joined to the second reinforcement 12 of the anti-vibration support 10. On the other hand, in the form of realization of Figure 8 as in the other embodiments, the limiting rings 28, 29 may have a single eyelet at their common end, or optionally may not have eyelets that delimit the holes for the passage of the cams that support these limiting rings: In this case, it is preferable that each limiting ring 28, 29 is previously compressed in permanent traction between the two cams to which it is attached.

Claims (10)

1. Automotive vehicle having a chassis (3), a powerplant (2) and a plurality of fastening devices (4, 5, 6) that support the powerplant and dampen the relative vibratory movements between the powerplant and the chassis parallel to the a first substantially vertical axis (Z), these fixing devices (4,5,6) allow the movements of the axis of the motor-driven block (2) in relation to the chassis (3) parallel to the first axis (Z) and at least parallel to a second axis (X) perpendicular to the first axis, at least one of these fixing devices called "first fixation device" (4), comprises: - a rigid support arm (7) attached to the block «that motopropulsor (2), the arm of support (7) and the chassis (3) are hereinafter referred to as the "first element" and the other, the "second element". an anti-vibration support (10) comprising a first rigid frame (11) fixed to the support arm (7), a second rigid reinforcement (12) fixed to the chassis (3) and an elastomer body (13) that joins the first and second reinforcements together and that supports the motor-driven block (2) allowing the relative axis movements mentioned above between the powerplant and the chassis, and a shaft movement limiter (14) which is able to limit the relative displacements between the powerplant block (2) and the chassis (3) parallel to the second axis (X), the The shaft movement limiter comprises a first rigid cam (16a, 16b, 11) extending in accordance with a direction perpendicular to the second axis (X) and which is connected to the first element, characterized in that the shaft movement limiter (14) ) further comprises: - the second (23, 23a, 37) and third (24,24a, 38) rigid cams which each extend in accordance with a longitudinal direction parallel to the longitudinal direction of the first cam and which are attached to the second element, the second and third cams are comprised in two planes perpendicular to the second axis (X) that are located on one side and the other of the first cam (16a, 16b, 11), and the first and second limiting rings (28, 29) have each one a winding (34) of resistant, flexible but substantially inextensible thread, covered by an elastomer coating (33), the first limiting ring (28) being fixed to the first (16a, 16b, 11) and second cams (23, 23a, 37) with its winding of resistant wire passed around the assembly of the first and second cams, and the second limiting ring (29) being fixed to the first (16a, 16b, 11) and third (24, 24a, 38) Cams with their winding resistant thread passed around the assembly of the first and third cams. Vehicle according to claim 1, in which the first and second restrictor rings (28, 29) constitute a single piece of elastomer (27) reinforced with resistant wire (34). Vehicle according to claim 2, in which the windings of resistant wire (34) of the first and second limiting rings (28, 29) are constituted by the same continuous wire. 4. An automotive vehicle according to any one of the preceding claims, in which each limiting ring (28, 29) has rigid reinforcements (35) that are wrapped in its elastomer coating (33) and that are interposed between the wire winding resistor (34) of the limiting ring and each of the cams (16a, 16b, 23, 23a, 24, 24a, 11, 37, 38) to which said limiting ring is attached. Vehicle according to any one of the preceding claims, in which each limiting ring (28, 29) forms two eyelets (30, 31, 32) which are respectively frictionally engaged on the two cams (16a, 16b, 23, 23a, 24, 24a, 11, 37, 38) to which said limiting ring is attached. Vehicle according to claim 5, in which the cams (16a, 23, 24) each have a free end forming an elongated head (22, 25, 26), the elongated heads of the three cams prevent the limiting rings (28, 29) from disengaging from said cams. Vehicle according to any one of the preceding claims, in which the first cam (11) is constituted by the first reinforcement of the anti-vibration support (10), while the second and third cams (37, 38) are attached to the chassis (3). ) vehicle. Vehicle according to any one of claims 1 to 6, in which the support arm (7) extends from the engine block (2) to an end fixed to the first antivibration support frame (11), and said arm of The support has an intermediate part that is located between the powerplant and the end and which is connected to either the first cam (16a, 16b), or the second and third cams (23, 23a, 24, 24a). Vehicle according to any one of the preceding claims, in which the elastomer body (13) of the anti-vibration support (10) has a bell shape that extends from a summit joined to the first reinforcement (11) to an annular base attached to the first reinforcement (12) partially delimiting this body of elastomer to a working chamber (A) communicating by means of a throttled passage (17) with a compensation chamber (B) bounded by a wall (18) easily deformable , the working camera, the clearing house and the passage estran <; gulate forming an airtight volume filled with liquid. Vehicle according to any one of the preceding claims, in which the engine block (2) is suspended pendulum, the engine block extends longitudinally according to a third axis (Y) horizontal perpendicular to the second axis (X) and which is attached to the chassis (3) by means of the first fixing device (4) associated with the second and third fixing devices (5, 6), the first and second fixing devices (4, 5) being substantially aligned parallel to the third axis (Y) and being fixed to the powerplant block at points located above the center of gravity (G) level of the powerplant, and the third attachment device (6) is attached to the powerplant block at a point below the first and second powerplant devices. fixation.