WO2008089973A1

WO2008089973A1 - Independent wheel suspension of a two-track vehicle with a guideway element

Info

Publication number: WO2008089973A1
Application number: PCT/EP2008/000505
Authority: WO
Inventors: Alfred Stenzenberger; Tobias Lorenz
Original assignee: Bayerische Motoren Werke Aktiengesellschaft
Priority date: 2007-01-26
Filing date: 2008-01-23
Publication date: 2008-07-31
Also published as: DE102007003950A1

Abstract

The invention relates to an independent wheel suspension of a two-track vehicle with a wheel carrier (1), articulation points (1b, 1c, 1d) for links (2, 3, 4) being provided essentially at said wheel carrier underneath the wheel centre (m), said articulation points being directly or indirectly supported at their other end at the vehicle body. An at least partially curved guideway element (7) that extends essentially in the vertical direction is provided at the wheel carrier and a guiding element (8), which is on the other hand directly or indirectly fixed to the vehicle body, is displaceably guided essentially above the wheel centre and along the guideway element. Furthermore, a support spring (5), which acts between the structure and the wheel carrier, and a vibration damper (10) connected in parallel thereto are provided. The support spring and the vibration damper are supported on one of the links or directly at the wheel carrier underneath or only little above the wheel centre. The vibration damper is preferably embodied as a rotation damper whose housing is supported at the vehicle body and whose pivoting arm is directly or indirectly connected to the wheel carrier.

Description

Independent wheel suspension of a two-track vehicle with a guideway element

The invention relates to a single-wheel suspension of a two-track vehicle with a wheel carrier, at which substantially below the wheel center articulation points are provided for handlebars, with its other end ultimately, i. directly or indirectly, are supported on the vehicle body and to which a substantially vertically extending at least partially curved guideway member is provided, on which substantially above the Radmitte a guide element, on the other hand ultimately, i. directly or indirectly, is fastened to the vehicle body, is guided displaceably along the guideway member, further comprising an ultimately acting between the structure and the wheel carrier and a spring of this parallel vibration damper is provided. In addition to DE 10 2004 048 789 A1, reference is made to DE 10 2004 035 320 A1 for the known state of the art.

In currently in series independent suspensions on the front and rear axles of two-track vehicles, especially passenger cars, handlebars are used for wheel guidance and transmission of forces from the vehicle body to the wheel. In the case of the so-called strut axle, in addition to the links, the vibration damper is used as a wheel-guiding element. The vibration damper is kinematically equated with a rotary thrust joint, the usually used linear vibration damper allows only rectilinear movements. Depending on the design of the suspension, the kinematic targets can be set more or less freely. Most restrictions have to be made with simple axles with only one handlebar, for example a skew. kerachse, be tolerated. In contrast, multi-link axles with up to five handlebars offer a maximum of tuning options for achieving the target values for lane, camber, roll center height and brake and drive support angle.

Multi-link axles generally have two link levels. The installation space of the lower handlebar level is limited by the ground clearance down. At least one link is usually located above the wheel center (and in the case of a driven axle above the drive shaft) and forms the upper link level. In order to meet the target values for the kinematic parameters of the axle over the Radhub, has the or the upper (s) handlebars on a certain minimum length. As a result, space in vehicle transverse direction is claimed. Thus, there is a conflict of objectives between the axle function on the one hand and the room functionality on the other hand in the wheel suspensions currently in series. It is possible to use either simple concepts with little space requirement (eg trailing arm axles or torsion beam axles) with limited possibilities in the kinematics design or multi-link axles with relatively high space requirements due to additional links but better kinematic tuning potential.

Radführungskonzepte are also known with physically trained at least partially curved guideways on which a guide element is guided longitudinally displaceable, see. For example, the two aforementioned writings. It is also already known to combine at least one guideway with handlebars, it is useful to provide the handlebars in particular below the center of the wheel, because the handlebars are better suited to accommodate the higher level of force in the lower arm level. In addition, in the lower vehicle area is generally sufficient space in the vehicle transverse direction available, so that hereby and with a provided above the wheel center extremely space-saving, at least partially curved guideway, with which a desired wheel can be implemented practically ideal, the conflict of objectives between space functionality and chassis function can be largely resolved in any case.

Nevertheless, improvements or favorable developments compared to this prior art are possible, which the present invention has set itself the task.

The solution to this problem is for a single-wheel suspension according to the preamble of claim 1, characterized in that the suspension spring and the vibration damper is supported either on one of the links or directly on the wheel below or just above the center of the wheel. Advantageous embodiments and further developments are content of the dependent claims.

It is not only necessary to reduce the space requirement of a functionally favorable wheel guide above the center of the wheel by providing a guideway or a substantially vertically extending guideway member relative to the usual handlebar arrangements, but it should also possible the suspension spring and one of these parallel-connected vibration need little space. For this purpose, at least the suspension spring can be supported either directly on the wheel carrier relatively close to the roadway and thus below or only slightly above the center of the wheel or on one of the lower links and thus be positioned as far down as possible in the vertical direction.

A corresponding arrangement is proposed for the spring operatively connected in parallel vibration damper. To achieve a minimum space requirement in the vehicle while the vibration damper can be designed as a rotary vibration damper, the housing is ultimately supported on the vehicle body and its pivoting arm is directly or indirectly ultimately, ie directly or indirectly, connected to the wheel carrier.

Coming back to the guideway or the guideway element, which naturally requires little space in the vehicle transverse direction, a targeted tuning of the kinematics parameters of the axis can be implemented both in the design position and on the Radhub by suitable design of the path radius of the guideway and the course of the radius change in the guideway , This results in enormous advantages in terms of the actual chassis function, namely the wheel guidance in dependence on current boundary conditions. Thus, the fall course to avoid too high a fall value in the fully loaded state of a passenger car up to a Radhub in the order of about 50 mm deflection progressive rising and designed for larger compression travel only linearly increasing. Furthermore, due to the already mentioned parameters "path radius" and "course of the radius change", the pitch behavior and the vibration behavior of the spring can be determined by a constant high kinematic brake support (eg 100%) and a constant small helical suspension angle (eg 4 °) Make vehicle advantageous.

Because of the requirements in terms of strength and rigidity and the suitability as a rolling bearing bearing track, the guide track element may preferably be made of a steel material. The wheel carrier, on the other hand, may be formed of a low-cost light metal or cast steel material depending on the load level and weight requirements. Preferably, the connection of the guide track element to the wheel carrier is designed to be detachable in order to allow replacement of the service case with little effort. In addition, by providing different guideway elements different kinematics levels can be displayed in an otherwise identical axis. As preferred variant to releasable connection between the track member and the wheel is proposed a clamping connection (clamping sleeve) with screw.

It is also proposed, the guide element for receiving the rotational movement occurring in connection with a Radhub occurring between the guide track element or the guide element displaceably guided thereon and the vehicle body via two rubber bearings ultimately attach to the body, which or its axis of rotation concentric with Main axis of the Führungsbahnelement- bearing is arranged on the wheel opposite the Fzg. -Aufbau. The position of this main axis of rotation results from that position at which the smallest Kardanikwinkel arise in the rubber bearing. This position can be determined by means of a kinematics simulation. Preferably, said rubber bearings are arranged in the vehicle while viewed in the direction of travel in front of and behind the guide track element, so that the space requirement in the vehicle transverse direction remains as low as possible. In addition to the above-mentioned function as a pivot bearing, these rubber bearings also serve for vibration decoupling and for receiving the aforementioned Kardanikwinkel.

For example, the rubber bearings can be connected to the guide element via a press fit and screwed with a readily accessible for mounting bracket with the Fzg. Construction. Moreover, at least one end stop for the guide element in the form of a rubber buffer may be provided on the guide track element.

In principle, as stated above, a guide track element arranged above the wheel center on a wheel carrier can be combined with different axle concepts or links which are articulated to the wheel carrier below the center of the wheel. Likewise - as stated - the suspension spring and a vibration damper different, but always as low as possible - be arranged. For example, a design similar to EP 0 288 654 B1 can be selected with regard to the support of suspension spring and vibration damper as well as with regard to the lower link plane, but alternatively also similar to EP 1 404 536 B1.

In the following the invention with reference to a preferred embodiment will be further explained, with the accompanying Figure 1 shows the wheel of the left rear wheel of a passenger car with arms, guide rail element, suspension spring and vibration in a spatial representation, while in Figure 2, this wheel is shown with the guide track element alone and Figure 3 shows the guide element with associated rubber bearings and holder also in a three-dimensional view. Essential to the invention may be all features described in more detail.

Reference numeral 1 denotes a wheel carrier basically known to a person skilled in the art, which has a contact surface 1a for a wheel bearing. Further, on the wheel 1 a pivot point 1 b for a trailing arm 2, a pivot point 1c for a crash bar 3, a pivot point 1d for a steering arm 4 and tie points 1e provided for a brake caliper, not shown a disc brake. The reference numeral 1f denotes the attachment point for a parking brake and the reference numeral 1g that for an ABS sensor. Finally, on that arm of the wheel carrier 1, which has the articulation point 1 b, nor a Abstützflansch 1 h for a suspension spring 5, via which the Fzg.- structure not shown is proportionally supported on the wheel carrier 1, provided. As can be seen, this support flange is 1 h relatively far below the wheel center M (M = center of the wheel bearing or the annular contact surface 1a for the wheel bearing) and thus relatively close to the road. Furthermore, a clamping sleeve 1 i is provided in an overhead, and thus of the roadway relatively widely spaced region of the wheel carrier 1, in the over a a clamping-causing screw 6 is held in a substantially vertically extending partially curved guideway member 7 (as explained above). On this guide track element 7, a guide element 8 is guided longitudinally displaceable.

In Figure 1, in addition to the elements mentioned so far, a drive shaft 9 for the wheel, not shown, and one of the only symbolically illustrated air spring element formed suspension spring 5 functionally parallel vibration damper 10, which is designed as a rotary damper and with its housing 10a on not shown Vehicle structure or on a longitudinal member thereof is fixed, while the pivot arm 10b of this conventional rotary vibration damper 5 is supported by a support 11 on the lintel 3.

In Figure 3, the guide member 8 with its holder 12 - this holder 12 is not shown in Figure 1 - and with rubber bearings 13, via which the guide member 8 is connected to the holder 12, shown. Here, the guide element 8 is here in the form of a simple pipe clamp, which / can be plugged onto the guide track element 7, shown. In fact, within this "pipe clip", i.e. on the inner surface of the guide element 8 facing the guide track element 7, plain bearings or rolling bearings are provided or formed, which is not shown here, since this is of no significance to the present invention.

Coming back to the guideway element 7, which is provided together with the guide element 8 instead of the upper link level of conventional suspension (eg similar to EP 0 288 654 B1 or EP 1 404 536 B1), the kinematics parameters can be determined via the local radius and curvature of the guideway formed thereby the suspension in both the design position and above the wheel stroke. be true. Such a guideway element or such a proportionate wheel guide on a physically existing guideway is suitable for use on both rear axles and front axles of two-lane vehicles. In particular, in conventional double wishbone front axles, the length of the upper arm is limited by the course of the engine mount. By using a guideway, a nearly arbitrarily long wishbone can be kinematically modeled. As a result, the camber course on the front axle can be made less progressive. Thus, the differences in the cambers between the rear axle and front axle can be minimized. This improves vehicle tuning with regard to lateral dynamics

The proposed solution offers the following advantages:

• Less space required for the suspension, especially in the area of the upper handlebar level

• Better adaptability of the wheel suspensions to the space requirements by the vehicle concept by the replacement of handlebars by guideways

• Benefits of kinematics design over the wheel stroke and in design attitude (e.g., constant brake and drive support angles, more flexible design of camber over the wheel stroke) through the tuning parameters radius of curvature and radius of curvature change over the wheel stroke and thereby advantages in lateral dynamics

• Improved coordination of the cambers of the front axle to the rear axle thanks to the more flexible design of the cambers on the front and rear axles, regardless of the given installation space, and thus advantages in tuning the driving behavior of the vehicle

• Better coordination of brake and approach support angle and thus advantages in pitch and vibration behavior

Claims

claims

1. independent wheel suspension of a two-track vehicle with a wheel carrier (1) on which substantially below the wheel center (M) Anlenk- points (1 b, 1c, 1d) are provided for handlebars (2, 3, 4), the ultimately with their other end, ie directly or indirectly, are supported on the vehicle body and on which a substantially vertically extending at least partially curved guideway member (7) is provided, on which substantially above the wheel center (M) a guide element (8), on the other hand ultimately, ie directly or indirectly, is fastened to the vehicle body, is displaceably guided along the guide track element (7), wherein furthermore a suspension spring (5) acting ultimately between the vehicle body and the wheel carrier (1) and a vibration damper (10) connected in parallel therewith is provided, characterized in that the suspension spring (5) and the vibration damper (10) either on one of the links (2, 3, 4) or directly on the wheel carrier (1) is supported below or only slightly above the wheel center (M).

2. independent wheel suspension according to claim 1, characterized in that the vibration damper (10) is designed as a rotary damper (10) whose housing (10a) ultimately supported on the vehicle body and its pivot arm (10b) directly or indirectly ultimately with the wheel (1) is connected.

3. independent wheel suspension according to claim 1 or 2, characterized in that the guide track element (7) releasably, in particular via a clamping (clamping sleeve 1 i), on the wheel carrier (1) is attached.

4. independent wheel suspension according to one of the preceding claims, characterized in that the guide element (8) via two substantially concentric with the main axis of rotation of the guide track element bearing on the wheel carrier (1) relative to the vehicle body arranged rubber bearing (13) with a holder ( 12) is connected, which in turn is attached to the vehicle body.

5. independent wheel suspension according to one of the preceding claims, characterized in that on the guide track element (7) an end stop for the guide element (8) is provided in the form of a rubber buffer.