Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G11/00—Resilient suspensions characterised by arrangement, location or kind of springs
  • B60G11/02—Resilient suspensions characterised by arrangement, location or kind of springs having leaf springs only
  • B60G11/08—Resilient suspensions characterised by arrangement, location or kind of springs having leaf springs only arranged substantially transverse to the longitudinal axis of the vehicle
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G11/00—Resilient suspensions characterised by arrangement, location or kind of springs
  • B60G11/32—Resilient suspensions characterised by arrangement, location or kind of springs having springs of different kinds
  • B60G11/34—Resilient suspensions characterised by arrangement, location or kind of springs having springs of different kinds including leaf springs
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G15/00—Resilient suspensions characterised by arrangement, location or type of combined spring and vibration damper, e.g. telescopic type
  • B60G15/02—Resilient suspensions characterised by arrangement, location or type of combined spring and vibration damper, e.g. telescopic type having mechanical spring
  • B60G15/06—Resilient suspensions characterised by arrangement, location or type of combined spring and vibration damper, e.g. telescopic type having mechanical spring and fluid damper
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
  • F16F1/00—Springs
  • F16F1/02—Springs made of steel or other material having low internal friction; Wound, torsion, leaf, cup, ring or the like springs, the material of the spring not being relevant
  • F16F1/18—Leaf springs
  • F16F1/26—Attachments or mountings
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G2202/00—Indexing codes relating to the type of spring, damper or actuator
  • B60G2202/10—Type of spring
  • B60G2202/11—Leaf spring
  • B60G2202/114—Leaf spring transversally arranged
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G2204/00—Indexing codes related to suspensions per se or to auxiliary parts
  • B60G2204/10—Mounting of suspension elements
  • B60G2204/12—Mounting of springs or dampers
  • B60G2204/121—Mounting of leaf springs
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G2204/00—Indexing codes related to suspensions per se or to auxiliary parts
  • B60G2204/40—Auxiliary suspension parts; Adjustment of suspensions
  • B60G2204/41—Elastic mounts, e.g. bushings
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
  • F16F2224/00—Materials; Material properties
  • F16F2224/02—Materials; Material properties solids
  • F16F2224/0241—Fibre-reinforced plastics [FRP]

Definitions

• This invention relates to a vehicle suspension.
• Suspensions according to the invention have been developed primarily to be used for the rear, unsteerable, wheels of a front wheel drive vehicle such as a passenger car, but it is to be understood that the invention is applicable to the wheels of other vehicles, and possibly for wheels which are steerable.
• Suspensions have been proposed which include a leaf spring or springs extending transversely of the vehicle, having its or their ends connected to parts which carry wheel and hub assemblies. It has been proposed that such a spring or springs may partake in the function of determining the path of wheel travel relative to the structure of the vehicle, to enable one or more arms, links or the like to be eliminated.
• a spring or springs may partake in the function of determining the path of wheel travel relative to the structure of the vehicle, to enable one or more arms, links or the like to be eliminated.
• disadvantages in that the path of wheel travel has not been sufficiently well constrained, which has disadvantages in terms of the handling characteristics of the vehicle.
• designs have been proposed which are relatively bulky and not easy to accommodate in modern vehicles where space is limited.
• a suspension for a pair of wheels of a vehicle comprising two leaf springs extending transversely of the vehicle generally parallel to one another and spaced from one another longitudinally of the vehicle, means supporting the springs relative to the vehicle structure at two positions spaced between the ends of the springs, for generally pivotal movement about axes extending transversely of the springs (i.e. longitudinally of the vehicle) , and a wheel carrier member at each side of the vehicle, connected to adjacent ends of the springs.
• the springs in addition to providing springing for the wheels, take part in determining the path of travel of the wheel carrier members relative to the vehicle structure.
• the springs provide good control of tracking of the wheels carried by the wheel carrier members.
• the springs resist roll of the vehicle so that additional components such as anti-roll bars are unnecessary.
• the leaf springs are made of composite, fibre-reinforced plastics, material.
• the structure of such springs can be determined such that they have an ability resiliently to deflect laterally so that the wheel carrier members are supported with a compliance (i.e. an ability to deflect slightly) in the direction longitudinally of the vehicle. This provides a bump softening effect.
• the use of the spaced springs ensures that wheel alignment remains well controlled even under such " conditions.
• Each wheel carrier member is preferably further connected to the vehicle structure by a respective generally vertically disposed telescopic damper unit.
• Each wheel carrier member may be rigidly connected to a part of its associated damper unit, and be connected to the ends of the springs for pivotal movement about an axis or axes extending generally longitudinally of the vehicle.
• damper unit in addition to the springs, the path of wheel movement is completely determined without requiring any additional links.
• damper unit in addition to the springs, the path of wheel movement is completely determined without requiring any additional links.
• the damper unit in a suspension according to the invention occupies relatively little space, and therefore does not intrude so much into the passenger or load carrying space of the vehicle.
• Such a damper unit may also, in known manner, incorporate means for levelling the vehicle by causing the suspension to assume a predetermined static position irrespective of load.
• the suspension may further comprise a sub-frame connected to the vehicle structure and extending transversely thereof, having mountings for supporting the springs relative to the sub-frame and thus relative to the vehicle structure.
• a sub-frame is advantageous in that it enables the suspension to be provided with the sub-frame as a complete assembly which can readily be fitted to a vehicle by the vehicle manufacturer. Further, the sub-frame may be arranged to be connected to the structure of the vehicle by mountings which resist the transmission of noise and vibration to the vehicle structure.
• the sub-frame may be of generally U-shaped configuration, having upwardly extending portions at each side of the vehicle which provide top mountings for the damper units. Such a sub- frame is readily accommodated in a vehicle structure.
• the sub-frame may afford a recess in which the springs are disposed. By being thus disposed, and possibly even within an enclosure formed by the sub-frame, the springs are protected from road hazards.
• a further feature of the invention is concerned with the means by which the springs are positioned in the direction transversely of the vehicle, to be able to resist forces imposed on the springs in the direction of their length when the vehicle is cornering and under other conditions in use.
• the spaced mounting.s of the springs to the vehicle structure by way of the sub-frame, which mountings usually will comprise suitable elastomeric bushes, have to withstand such forces.
• the invention therefore provides that there may be at least one resilient element extending generally parallel to the springs, and connected on the one hand to the springs between their support positions and on the other hand to the vehicle structure, to resist movement of the springs along their length while permitting bending thereof.
• a resilient element which may be of composite material or of spring steel, relieves the spring mountings of lateral forces while permitting bending of the springs between their mountings.
• resilient means arranged to act between the vehicle structure and the springs between their support positions, in the direction in which the springs principally deflect in use. This enables adjustment of the spring rates in jounce and/or rebound, without, theoretically, affecting their roll rates.
• a further aspect of the invention is concerned with providing the suspension with a variable rate, i.e. a variation in the force required to produce a given deflection of a wheel of the vehicle.
• the rate may be required to rise with increasing wheel deflection in jounce.
• the suspension may be provided with a leaf spring portion connected to each wheel carrier member and arranged, during an initial part of jounce movement thereof, to exert a force opposing that exerted by at least one of said springs, and during a further part of such movement to pass through a neutral position and thereafter to exert a force augmenting that exerted by said at least one spring.
• Figure 1 is a diagrammatic perspective view, partially broken away " for clarity, of a suspension according to the invention
• Figure 2 shows diagrammatically how the suspension would be incorporated in a typical motor vehicle, namely for the rear wheels of a passenger car;
• Figure 3 is a diagrammatic perspective view of a suspension according to the invention incorporating a modification
• Figure 4 is a diagrammatic view of the mode of operation of yet a further modification of a suspension according to the invention.
• Figure 5 is a diagrammatic perspective view of a suspension incorporating the modification of Figure 4.
• a suspension for a pair of wheels of a motor vehicle is for the rear wheels of a relatively light vehicle such as a passenger car.
• the suspension comprises a sub-frame 10 which is generally of U-shape, extending transversely of the vehicle and having upwardly extending portions 11 at each side of the vehicle.
• the sub-frame 10 is a metal pressing or a fabrication from metal pressings and is in the form of a shallow trough whose open face is at the bottom of the part of the sub-frame which extends transversely of the vehicle and the outer sides of the upwardly extending- parts.11 of the sub-frame.
• Two leaf springs 12, 13 are disposed within the recess or trough defined by part 10 of the sub- frame.
• the springs extend transversely of the vehicle parallel to one another, and spaced from one another longitudinally of the vehicle.
• Spring 12 is supported relative to the sub-frame by two mounting assemblies 14, 15 which comprise elastomer ic bushes held in sheet metal supports secured to the sub-frame by being bolted thereto.
• Such mountings each provide for pivotal movement of the spring through a small angle, about a respective axis extending transversely of the spring, i.e. longitudinally of the vehicle.
• Spring 13 is similarly supported by two mounting assemblies one of which is indicated at 16, such mounting assemblies being in line with those for the spring 12.
• the springs 12, 13 are preferably of composite, fibre-reinforced plastics, material. They may be of uniform cross-sectional shape and area throughout their length, or may be non-uniform. For example, they may taper to become thinner between their positions at which they are supported relative to the sub-frame, so that in use the majority of resilient bending of the spring occurs in such region rather than in the portions of the springs outboard thereof.
• the springs need ' not be identical to one another, but it is preferable that they are identical so that the number of different parts required in the suspension is minimised.
• springs 12, 13 are provided with eye end fittings 17, 18 which may be of the type disclosed in our International Patent Application Publication No. WO85/00643, to which reference should be made for a more detailed description of these parts-.
• Bushes e.g. of the resilient metal-rubber-metal type, held to the spring receive a bolt 19 to secure a wheel carrier member 20 to the spring, and provide for relative pivotal movement between the wheel carrier member and spring about the axis of the bolt 19.
• the wheel carrier member 20 is rigidly secured to a lower part 21 of a telescopic damper strut, whose upper part 22 is fixed, by a resilient mounting, to the top of the associated sub-frame part 11.
• the wheel carrier member 20 supports a conventional assembly of stub-axle, bearings, and wheel hub, for rotation of the wheel about an axis 23.
• the wheel, indicated as 24, at the opposite side of the vehicle is similarly supported by a mirror-image identical arrangement of wheel carrier member and telescopic damper.
• each spring 12, 13 is mounted to the sub-frame at the two positions spaced lengthwise of the spring means that the springs resist roll of ' the vehicle, in generally known manner.
• the configuration of the springs is such that the wheel carriers are held in a well controlled alignment relative to the vehicle structure, preferably eliminating the need for any additional tie rods or the like connecting the wheel carriers to the vehicle structure, although it would not be outside the scope of the invention if such components were provided.
• FIG. 2 of the drawings shows, in a diagrammatic side view, how the suspension may be incorporated in a vehicle.
• the rear part of a passenger car is diagrammatically shown, with a wheel arch structure 25 providing clearance for a wheel 26.
• the floor pan structure of the car is indicated at 27, and it will be noted tha the part 10 of the sub-frame extends transversely of the vehicle therebeneath in the rear seats/luggage-boot area of the car.
• the respective portion 11 of the sub- frame, containing damper 21, 22. and wheel carrier 20 (not shown in Figure 2) , is readily accommodated in the wheel arch structure.
• the invention thus provides a suspension which uses relatively few parts and is easily accommodated in a typical vehicle structure.
• the suspension is advantageous when applied to the rear wheels of a vehicle, but it may nevertheless be possible for the wheel carrier members to provide for some steering swivel ing movement of the wheels.
• the springs 12, 13 are protected by virtue of being disposed within the trough afforded by the sub- frame.
• the trough may be closed by a lower cover member, so that the greatest part of the length of the springs, and in particular their mountings, occupy an enclosure so as to be better protected from road dirt and grit, stone chippings and othe.r hazards which could otherwise damage the springs.
• the springs 12, 13 being completely separate, it would be possible for them to be connected in their centre regions to form an integral structure of composite material.
• the mounting assemblies as 14, 15 for the springs may have a st.iffness in directions transversely of the vehicle (longitudinally of the springs) controlled such that under cornering conditions a change in wheel attitude occurs to give the vehicle desirable handling characteristics, e.g. to control an understeer condition.
• The- suspension comprises two leaf springs 110, 111 extending transversely of the vehicle and spaced from one another longitudinally of the vehicle, the springs being supported by assemblies including elastomeric bushes indicated as 112. These provide for limited pivotal movement of the springs about axes extending transversely thereof, i.e. longitudinally of the vehicle parallel to the longitudinal centre line of the vehicle which is indicated at 113.
• the wheel carrier member pivotally connected to the ends of the springs is indicated at 114, and a stub-axle 115 thereon is shown diagrammatically at 115.
• a telescopic damper is indicated at 116, with a top mounting 117.
• the springs 110, 111 are further connected to the sub-frame by a locating element 118.
• This is of resilient material, e.g. spring steel or a fibre-reinforced plastics material, and in the embodiment illustrated is of generally Y-shape in plan view with its two limbs connected to the springs 110, 111 at 120 (at the vehicle centre line 113) , and its single opposite limb connected to the sub-frame at 119.
• the element 118 thus maintains the springs 110, 111 in the desired position transversely of the vehicle, under cornering forces.
• the bushes 112 are largely relieved of having to withstand such forces.
• the resilient element 118 does not hinder to any substantial extent vertical movement of the centre part of the springs.
• the amount of movement vertically of the centre of the springs relative to the sub-frame is comparatively small when the vehicle's wheels deflect in jounce and rebound alone, and theoretically is zero. or roll deflections, and hence the connection of the centres of the springs to the sub-frame by way of element 118 does not impose unacceptable transverse movements on the springs.
• the ends of the parallel limbs of the element 118 have been shaped to a reflex form at 121, where they may abut a suitable part of the sub-frame.
• they provide a spring force acting downwardly on the centres of the springs. This lowers the rate of the suspension for wheel deflections in jounce, without altering the rate for roll deflection.
• Springs which are relatively stiff may thus be used to achieve a high roll rate without leading to a high rate in jounce.
• individual transverse resilient elements may be provided to connect the springs to the sub-frame.
• FIG. 4- of the d awing-S,. the-r-e. is shown diagrammatically part of an arrangement by which a suspension according to the invention may be made to provide a dual rate.
• an assembly comprising three leaf spring portions 210, 211, 212, held together, at a position spaced from their ends by a fastening 213.
• the free ends of the leaf spring portions are provided with eye end fittings (as indicated at 214 for the spring 210) for receiving a fixing pin extending along axis 215.
• the spring assembly is intended, to provide a spring force acting in a downwards direction, with reference to the drawing, at the free ends of the leaf springs.
• Springs 210, 212 are of substantially the same shape as one another when unstressed, and this shape will be assumed to be that shown in the drawing.
• Spring 211 is of a different shape when unstressed such that its end part would assume a higher position than the ends of the springs 210, 212.
• the free position of the spring 211 is shown in broken lines in Figure 4 of the drawings. Therefore, when the eyes of the free ends of the springs are held in alignment with one another by the pin passing therethrough, spring 211 exerts a force which opposes that exerted by the springs 210, 212.
• FIG. 5 shows how the principle may be applied to a vehicle . suspension according to the invention.
• the sub-frame has been omitted for clarity, and the suspension comprises three leaf springs 220, 221, 222 extending transversely of the vehicle.
• the longitudinal centre line of the vehicle is indicated at 223.
• the springs are each mounted to the sub-frame by two elastomeric bush assemblies 224, 225, equally spaced on opposite sides of the centre line 223.
• the path of wheel movement relative to the vehicle is thus determined by the combination of the springs and the damper strut.
• the unstressed shapes of the springs 220, 221, 222 are selected so that the centre spring 221 opposes the force exerted by springs 220, 222 for an initial part of upward wheel movement relative to the vehicle, and then during a further part of such movement augments the force exerted by springs 220, 222.
• a change in suspension rate is thus obtained, the geometry of the springs being selected so that ' the change occurs at the appropriate point in the path of wheel travel to suit the vehicle in question.
• the difference in the unstressed shapes of the springs 220, 221, 222 is shown at the ends thereof in broken lines in Figure 5.
• the additional spring 221 assists the resistance of the suspension to wheel movement longitudinally of the vehicle.
• spring 221 extends transversely across the whole width of the vehicle between the wheels thereof, separate spring portions may be utilised at each side of the vehicle. Such spring portions could be rigidly secured to the sub-frame at respective mounting points positioned as mountings 224, 225.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Vehicle Body Suspensions (AREA)
• Springs (AREA)

Applications Claiming Priority (6)

Publications (1)

Family

ID=27262817

Family Applications (2)

Family Applications After (1)

Country Status (3)

Families Citing this family (9)

Family Cites Families (6)

• 1986
  • 1986-10-03 WO PCT/GB1986/000596 patent/WO1987002316A1/en not_active Application Discontinuation
  • 1986-10-03 EP EP19860905897 patent/EP0276218A1/de active Pending
  • 1986-10-03 GB GB8808066A patent/GB2203708B/en not_active Expired
  • 1986-10-03 EP EP86307645A patent/EP0220854A1/de not_active Withdrawn

Non-Patent Citations (1)

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