JPS58112814A - Car suspension-system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to vehicle suspension systems.

The installation of all drive assemblies in either the front or rear compartments of modern vehicles, combined with the general trend towards reduced volume and mass in those areas of the vehicle body, has made it difficult for conventional chassis It imposes substantial design constraints on the use of systems, particularly vehicle suspension elements. The space and structure previously utilized to locate items such as suspension control arms, vertical shock struts, coil springs, etc. is now required for drive train components.

Moreover, it is a completely satisfactory solution since modern suspensions combining springs and shock absorber struts of the so-called MacPherson type require high hood and quarter profiles associated with the vertical stacking of suspension elements typical of such arrangements. It does not give

The present invention relates to vehicle suspension systems that give vehicle designers greater freedom in both space utilization and vehicle body styling.

In accordance with the present invention, in a suspension system for a sprung mass of a vehicle for a pair of transversely opposed wheels, the entire sprung mass is adapted to carry a respective one of each wheel and the entire sprung mass is disposed on each side of the sprung mass. a transverse control arm swingably mounted on a shaft extending longitudinally to the control arm and extending transversely to the sprung mass proximate the control arm but spaced from the control arm longitudinally of the sprung mass; a primary suspension spring having an elastic beam having an end projecting outwardly from a substantially perpendicular plane containing the swing axis of the control arm; by connecting at a position on the latter outward from their respective planes and acting to transmit to the beam a force effective to deflect the control arm relative to the sprung mass 14, so that the beam under the action of such force means adapted to bend about a pair of spaced nodal points located substantially inside said coupling location; and reaction mount means on the sprung mass engaging the resilient beam at the nodal points. A suspension system is provided having.

The suspension system therefore includes a pair of transversely oriented control arms for the opposing wheels, which are adapted to swing about the longitudinal axis of the sprung mass in a conventional manner. However, rather than connecting a primary suspension coil or similar spring on each side in the vicinity of each wheel to this control arm, this secondary suspension spring is spaced longitudinally from the control arm and is therefore free of other components. It has a transversely elastic beam that may be in areas of the vehicle where it is not needed. Substantial space is thus made available laterally between the control arms, for example for drive assemblies, and near and above the wheels which would normally be consumed by compressible coil springs on MacPherson struts etc. space will also be made available.

This general arrangement of transversely extending primary suspension springs spaced longitudinally of the vehicle from the control arm has been proposed in the past, but appears to have been commercially unsatisfactory. namely, a transverse primary spring beam, a known quadrilateral suspension linkage, and a torsion bar extending from a lower quadrilateral arm along its pivot axis to connect such control arm to opposite ends of the suspension spring. Suspension arrangement! is known (for example, U.S. Pat. No. 37
01542, 3831966). Such a known arrangement is such that the bending mode of the transverse spring caused by the deflection caused by normal vehicle running and wheel steering is caused by a specially proposed connection between the ends of the transverse spring and the two torsion bars. Requires scales that are regulated only by the system.

Such proposals are known (for example, US Pat. No. 3,701,542,
No. 3,831,966) and is considered to be clearly unsatisfactory from several functional and structural points of view.

On the other hand, the vehicle suspension system of the present invention represents a commercially superior arrangement of transverse spring suspensions.

During the development of the present invention, it was discovered that reinforced polymeric materials, such as fiberglass filled polyester resins, exhibit excellent properties for use in spring beams. The present arrangement of transverse spring beams allows beams made of such materials to be effectively used not only as primary suspension springs, but also as the primary main bore for controlling vehicle handling characteristics as the only anti-roll element. be. This provides a practical arrangement that not only avoids the conventional elaborate type of interconnection between the flexing wheel control arm and the suspension beam, but also eliminates the functional deficiencies of previous configurations. be done.

A vehicle suspension system according to the present invention is each simply fixed to a control arm at one end and aligned along a longitudinal axis of the chassis spaced outside of the control arm pivot;
Then, at the other end, the control arm is simply fixed to the end of the transverse beam such that the deflection of the control arm causes the transverse beam to undergo a bent mode characterized by a pair of internal nodes in the beam at the fixed location of the sprung mass. The invention is characterized by the use of interconnecting elements such as torsion rods. This nodal bend property provides for and is a consequence of the simple connection described above. The known structures (e.g. U.S. Pat. No. 3,831,966)
In No. 1, the interconnections at both ends of the transverse beam, although elaborate, are subject to a large amount of relative sliding movement between the beam ends and the interconnecting elements as beam deflection occurs, and the threaded rod is subjected to loads both in bend mode and in torsion. In the present invention, the nodal bending characteristic enables a shape in which such a noticeable relative displacement does not occur.

Moreover, if long torsion rods are chosen as interconnecting elements, as is the case in the preferred embodiment of the present system, an additional advantage is obtained from the fact that longitudinal bending of the torsion rods does not occur, which is not previously required. In contrast to what has been described, no independent structural support of this rod on the sprung mass of the chassis is required.

More specifically, the nodal beam bending characteristic of the present invention is such that both the beam end and the mooring points by the control arms at both ends of the torsion rod draw approximately the same arcuate locus in a spatially parallel plane when the wheel is deflected. The distance between the control arm axis and torsion rod axis on the beam and torsion rod (if such is used)
The choice is intended to be made regarding the properties of the material. The torsion rod or other interconnection device merely acts to transmit a pure force couple between the control arm and each beam end. To complete the system, reaction load elements are provided on the sprung mass of the chassis at the nodes of the beam to act as spring compression during vehicle roll. Such a system as a whole is unique, without having to unduly sacrifice one function to benefit the other! or the use of the previously mentioned lightweight polymeric springs as the primary travel and untie roll rate control elements. A further advantage in this respect is that by judicious design of such nodal reaction elements, additional freedom is available to the designer in selecting the spring beam and thus the vehicle's running and anti-roll behavior. It can be expected in the fact that it becomes difficult to understand.

The use of all of the foregoing accomplished objects and features of the present invention results in a suspension package that is lightweight, space efficient, and simple to construct.

It is also possible to easily accommodate the spring beam in a relatively shallow box section crosspiece of the vehicle, provided that the spring is located in a low-level free space for the engine assembly and is protected from road hazards. be.

The suspension further includes an exemplary embodiment via an adjustable lever arm device capable of providing variable breast resting of the torsion rod and spring beam to support the vehicle sprung mass at variable design heights. The design may feature a height adjustment facility with a torsion rod connected to each control arm.

Referring in particular to FIG. 1, this figure shows the front portion of an automobile chassis and front suspension in accordance with the present invention for steerable front wheels as shown in phantom 1°. The front wheels are adapted to be connected via a drive shaft assembly 12 to a front drive assembly which may be located within the front compartment of the vehicle body or sprung mass as is well known in the art. Although this vision is directed to the packaging and body styling issues that arise with such front drive designs, the invention also applies to vehicles with rear drive assemblies or where space efficiency is an issue. Note that fits the others equally well.

In the illustrated front-drive vehicle, the vehicle sprung mass or chassis/body is a stamped sheet metal welded tube section rail 1.
The drive assembly receiver may consist of a platform 14 including a preassembled combination of front and rear spaced apart cylindrical crosspieces generally indicated at 6 and 18 and 20. Such a receiver supports a vehicle drive assembly (not shown) and is conventionally bolted to the remainder of the vehicle body via a standoff mount.

The vehicle suspension of the present invention, in the preferred embodiment, is constructed to include elements currently found in vertical strut/shock suspensions;
'It should be understood that the principles of the invention are not limited to this. The vertical strut/shock 22 has an outer shock cylinder 24 and a mating piston rod suitably moored to the upper sheet metal tower structure 28 of the body sprung mass via a conventional isolation coupling, such as shown at 30 in FIG. It consists of 26. As is well known, this strut/
The shock 22 has ears for receiving a pair of spaced through bolt and nut assemblies 34 that are welded or otherwise secured to the cylinder 24 and attach the strut/shock 22 to the top of a conventional wheel support or knuckle 36. A saddle bracket 32 may also be included. As is known, this knuckle, in the case of a driven or live axle wheel, includes provision for passing the drive shaft 12 through the knuckle as a live axle as shown here. Although the space utilization advantages of the present invention are generally directed to packaging problems in drive assemblies, they are equally applicable to base axle suspensions or older style propeller axle rear drive vehicles that are remote from the drive assemblage.

The suspension of the present invention includes a transverse control arm 38 for the wheel 10, swingably mounted on the vehicle chassis sprung mass, for example at the rail 16. This control arm therefore has a bolt/strike seat within its spaced legs.
Rail 1 via fastener 44 (Figures 3 and 4)
It is mounted for pivoting on axis A at the center of a pair of aligned pivot assemblies which may be conventionally constructed with a rubber sleeve 40 affixed to a bracket 42 of No.6. The outer end of the control arm 38 is provided with a conventional ball joint 46 located within the lower part of the nut 36. As is known, this ball joint is a strut/shock 2
2 defines a steering axis for the steerable wheels 10 under the action of a known steering linkage, not shown.

Referring again to FIG. 1, in accordance with the principles of the present invention, a transverse spring beam 48 is provided. This spring is housed within the confines of the front barrel crosspiece 20 and extends completely through it, symmetrically about the vehicle centerline and on the opposite side in a manner similar to that described below for the illustrated wheel 10. It has the same connection as the steerable wheels 10. Accordingly, the descriptions made above and below regarding the structure shown apply equally to the other half of this suspension embodiment. Regarding the beam 48, although the present invention is not limited in any way to the selection of spring material, the present invention may nevertheless be constructed of a reinforced polymeric material such as polyester resin reinforced with fiberglass. It turned out to be best implemented with a beam. Such spring beams absorb high amounts of strain energy while achieving low weight,
and exhibits a modulus of elasticity well suited for use in both ride and vehicle roll rate control as applied as described below.

As seen in FIGS. 2-4, spring beam 48
are arranged according to the invention in such a way that their terminal ends extend substantially laterally beyond a baking soda plane B containing the pivot axis A of both control arms 38. In this embodiment, the control arm 38 is connected to the protruding end of the spring beam 48 by a pair of torsion rods 50. The torsion rods are each located along an axis C (FIGS. 3 and 4) that is external to the control arm's pivot axis A. Each terminal end 52 of the spring beam 48 carries a clamp assembly 54 which encloses the end of the beam and consists of mated upper and lower portions joined by a fastener 56 extending through a hole in the beam end 52 and a further fastener 58. There is. An isolation sleeve 60 made of a material such as rubber is interposed between the beam end 52 and the clamp assembly. The top of the clamp assembly is suitably drilled and mates with an outer spline on the front end of the torsion rod 50 to connect each torsion rod to the spring beam 48.
It includes a boss 62 provided with internal splines that establishes a torque-bearing connection in axis C with.

At its other end, the torsion rod carries a similar external spline and is received within a design height adjustment device for control arm 38. The device has an elongated tubular lever member 64 rotatably carried at its rear end within a control arm pocket as shown in FIGS. This lever member has an arm or crank portion 66 extending transversely to the ball joint 46.

As best seen in FIG. 2, the end of this crank portion protrudes from a hole in the control arm 38 and rests on a diagonal bolt head 70 secured thereto. It is bored and threaded to receive a threaded shank. The torsion rod 50 is thus placed in a torque-bearing relationship between the control arm swinging about axis A and the resilient spring beam 48. As can be seen in Fig. 5, when the front weight of the axle's sprung mass is multiplied by the weight W/2 on the bushing 40 at each axis A, the ground reaction force W/2 on each wheel 10 represents only the vehicle weight. and creates a force couple M in each control arm 38 which tends to induce counterclockwise rotation of the control arm as viewed in FIG. This force couple M is carried in axis C through torsion rod 50 to beam end 52 to deflect beam 48 according to its elastic modulus, and torsion rod 50 is torsionally deflected according to its elasticity. As a result, the control arm 38 assumes a particular angular position that defines a so-called "design height" for a particular sprung mass in a so-called "design load", for example two passengers and a large amount of cargo. Lever member 64 provides convenient adjustment of the position of each control arm 38 about pivot axis A in the presence of such deflection under the weight of its particular sprung mass. The latter design height is easily adjusted by screw rotation of the stud 68 to change the angular relationship of the control arm and thus the sprung mass in relation to the crank portion 66 of the loaded torsion rod 50.

As a result of the interrelation of the parts described above, a pair of neutral or nodal points of deflection are defined within the spring beam 48, for example, spaced apart along axis D (FIGS. 1, 2 and 4). Accordingly, as viewed in FIG. 2, due to dynamic road forces which deflect the wheel 10 upwardly to the dashed position shown, the torsion rod will bend the spring beam in a manner as shown at 48'. increases at the beam end 52 and applies a nine-couple force.

This bending occurs while the beam remains essentially vibrationally unperturbed relative to the sprung mass cross member 20 in space or along the cylinder axis. This also applies to the opposite deflection of wheel 10 and the deflection of spring beam 48 to a position such as that shown at 48'' in FIG.

This beam bend node characteristic is such that even though both axles 1o deflect in the same direction during a pure running motion, during a turning motion where a roll couple applies a force across the vehicle that causes both axles to deflect in opposite directions. This is true even if they bend in the same direction. As shown in FIG. 6, in the case of the former pure running motion, the beam is in the so-called "pure iV)'", i.e.
Only the uniform force couple ΔM acts counter-rotationally on the beam ends such that no vertical reaction force is required to hold the beam spatially fixed relative to the sprung mass. .

As can be seen in Figure 7, during roll motion, the vents are present in the beam to accommodate a situation in which the couple is in the same direction and tends to displace the beam entirely by -9 relative to the sprung mass. converted to a higher order wavy curvature.

In such a case, a vertical reaction force F is spatially required and is characteristically provided in the present invention by suitable spring reaction mounts, described below, located at a pair of spaced nodes in the axis. In the suspension shown in FIGS. 6 and 7, which combines certain parts of the two theoretically pure cases, various dynamic road force states are naturally induced, but in which case the beam 48 It is expected that the bend will occur around the characteristic node in the axis.

It is one feature of such beam vent characteristics in both cases that all such pends can be advanced without any significant relative movement between the beam ends 52 and the respective control arms 38 on either side of the vehicle. Thus, as viewed in FIG. 2, a point on control arm 38 in some transverse vertical plane in which torsion rod 50 is centered is
Virtually the same arc of motion can be described by a point on the beam end 52 of the spring beam in the parallel transverse vertical planes about which the other end is centered. These must be the same.
can be seen by the single arc C at each beam end appearing in FIGS. 6 and 7.

Although the curved path of the beam end 52 is essentially drawn about one axis of the cylinder, the arc of motion of the rear end of the threaded rod 50 is of course centered around the axis A of the bushing 40. Although some minor differences in curvature may exist, by appropriate selection of the elasticity of the torsion rod and the spring beam 48, these paths in two separate transverse planes are essentially a torsion rod. 5
The passage may be such that there does not need to be any significant bending force longitudinally along axis C in 0. Such a torsion rod therefore simply carries a pure force couple associated with the deflection of the wheel 10 about axis A.

No separate support of the torsion rod is required on the sprung mass.

And the fact that the torsion rod 50 is located further away from axis A makes it easier for the control arm 38 to move than in the prior art where the torsion rod was placed directly on such axis A and the control arm pivot had to be specifically modified accordingly. and the construction 11 of the bushing 40 is essentially simplified.

As best seen in FIG. 2, the axially acting mounts for the system are shown at 72, each of which is simply a light force fit between the inner surfaces of the transverse member 18 and the beam 4B. It has a pair of tapered blocks made of rubber or other material. The hardness of the rubber provides isolation of the road pothole from the vehicle sprung mass without significantly softening the vertical restraint of the cylinder axis under force F within the free body force situation represented in Figure 7. selected to best achieve this. However, the shape of said block, or the softness of its material, or some suitable combination thereof, may be such that, for example, the roll rate of the suspension can be easily adjusted without affecting the running rate simply by changing the action at the nodes of the spring beams 48. It is anticipated that it will be appreciated that the present invention provides further advantages in allowing further design flexibility as it may be adjusted.

Due to the lateral spacing between the so-called rotation axes of the beam end-2 at D and the control arm at A, an imbalance occurs in the angular deflections experienced by the ends of the torsion rod 50 during wheel deflection. Such unbalance induces torsional deflections in the rod 50 during wheel flexure, giving rise to consideration of the torsion rod material for proper design of the running and roll characteristics of the suspension system. However, as indicated above, the present invention is limited to the use of such threaded rods in practice, since other means may also provide satisfactory results, such as, for example, a longitudinal extension of stamped metal from the control arm 38. It's not a thing. cost, weight,
Various concerns, such as the desired positioning of the transverse spring beam longitudinally away from the control arm for efficient space utilization, all come into play in making such a choice. It is clear that the principles of the present invention give rise to numerous possibilities for making practical suspension configurations of this general type possible that were not previously possible.

[Brief explanation of the drawing]

FIG. 1 is a fragmentary perspective view of the sprung mass of a vehicle chassis having an embodiment of the wheel suspension according to the present invention, partially shown by imaginary lines, and FIG. 2 is shown by line 2-2 in FIG. 1. FIG. 3 is an enlarged fragmentary elevational view partially cut away in the direction of the arrow in the plane showing the wheel suspension in several wheel positions; FIG. 3 is a plane taken along line 3-3 in FIG. Figure 4 is the same as Figure 3, but in the plane indicated by line 4-4 in Figure 3. 5 to 7 are schematic illustrations of the various bending modes of the spring beam of the suspension system. [Explanation of symbols of main parts]. 10...Wheel 14...Spring mass ・18・
... Lateral member 38 ... Transverse direction control arms 48 ...
Transverse spring beam 50...Torsion rod 52...Terminal end 72 of spring beam 48...Free state of reaction mount F spring 48

Claims (1)

Claims: 1. A suspension system for a sprung mass (14) of a vehicle on a pair of transversely opposed wheels (10), each carrying a respective one of the vehicle $1 (101); a pair of transverse control arms (38) swingably mounted on their generally longitudinally extending axes on each side of the sprung mass (14);
extending transversely to the sprung mass (14) in close proximity to 2
is spaced from the control arm (38) in the longitudinal direction of the sprung mass (14) and projects outwardly from a substantially perpendicular plane containing the pivot axis (A) of the control arm (38). ) a primary suspension spring having an elastic beam (48);
Each control arm (38) is connected to each end (52) of the elastic beam (48) at a position (C) on the elastic beam outward from the respective substantially perpendicular planes, and the sprung mass (14) ) by transmitting a force to the beam (48) that causes the control arm (38) to deflect relative to the pair of spacings, such that the beam (48) under the action of such force is located substantially inside said coupled position. means (50) adapted to bend at a node +D) and reaction mounting means (72) on the sprung mass (14) and engaging the elastic beam (48) at that node. Suspension with
system. , a suspension system according to claim 1, wherein the secondary suspension spring comprises a beam (48) of resilient polymeric material, and a torsionally resilient means (50) is arranged in each control arm (38). ) to each end of the beam (4B). , % A suspension system according to claim 1 or 2 for a vehicle having a frame cross member (18) spaced longitudinally from a pair of transversely opposed wheels (10). In the suspension system of
A suspension system in which an elastic beam (48) is arranged within the frame crosspiece (1B). 4. In the suspension system according to any one of claims 1 to 3, the sprung mass (
14) Reaction mounting means on and engaging the beam (48) at its nodes are seated on the crosspiece (18) and 7
'Suspension system with CI pairs of opposed elastomer blocks (72). 5. In the suspension system according to any one of claims 1 to 4, the control arm (38
) to each end of the beam (48) comprises a pair of torsion rods extending on axes substantially parallel to, but external to, the pivot axis of the control arm (38); a suspension system each connected at one end to a respective control arm (38) and affixed to the end of the beam (48) at the other end. 6. In the suspension system according to any one of claims 1 to 5, the control arm (38
) are each adjustably connected at said one end thereof to a respective control arm (38) by a respective sprung mass height adjustment means (68).