WO2013143634A1

WO2013143634A1 - Suspension device of a motor vehicle having a tandem axle

Info

Publication number: WO2013143634A1
Application number: PCT/EP2013/000260
Authority: WO
Inventors: Johannes Marcea
Original assignee: Daimler Ag
Priority date: 2012-03-27
Filing date: 2013-01-29
Publication date: 2013-10-03
Also published as: EP2830896A1; DE102012006116A1; CN104203606A

Abstract

The invention relates to a suspension device (10) of a motor vehicle, having at least one spring device (12) arranged on a frame element (22) of the motor vehicle, by way of which two axles (14, 16) of a tandem axle (18) of the motor vehicle arranged consecutively in the longitudinal direction of the vehicle are supported in an spring-loaded manner by the frame element (22). The spring apparatus (12) comprises a first spring part (24) that is held on the frame element (22) such as to be pivotable about a first pivot axis (26) and is dedicated to the first of the axles (14, 16) and a second spring part (30) that is held on the frame element (22) such as to be pivotable about a second pivot axis (32) and is dedicated to the second axle (16). The spring parts (24, 30) are coupled to one another by way of a lever arrangement (36).

Description

SUSPENSION APPARATUS OF A MOTOR VEHICLE WITH A TANDEMACHSE

The invention relates to a suspension device of a motor vehicle, in particular of a commercial vehicle, according to the preamble of patent claim 1.

Such a suspension device of a motor vehicle, in particular a

Nutzkraftwagens, EP 0 579 183 A1 can be seen as known. The

Suspension device comprises a arranged on a frame member of the motor vehicle spring means, via which two in the vehicle longitudinal direction successively arranged axes of a tandem axle of the motor vehicle are resiliently supported on the frame member. The spring device comprises a leaf spring arrangement for the resilient support of the axes.

The leaf spring assembly is pivotally supported about a pivot axis relative to the frame member on the frame member. Thus, the leaf spring assembly when rebounding and rebounding of the axes about the pivot axis back and forth. The

Leaf spring assembly is thus also referred to as a pendulum spring.

Such suspension devices have the particular disadvantage that the kinematics of the pendulum spring is unfavorable in relation to axle-guiding link elements. This results in high bearing loads, in particular a rubber compression spring for supporting at least one of the axles on the frame element. Furthermore, the

Axle load compensation between the axles of the tandem axle impaired. These kinematic constraints lead to a difficult to calculate hysteresis. This means that power and / or torque curves in the conventional

Suspension devices are not or only very imprecise to determine and

are to be understood. This adversely affects the structural design of the suspension devices.

This also leads to problems, the driving behavior of the motor vehicle in the context of so-called multi-body simulations map and simulate. The corresponding Spring rate of the spring device also represents an unfavorable compromise between ride comfort and Wankfederrate.

In addition, the leaf spring arrangement with its plurality of leaf spring elements on a progressive spring characteristic, which leads due to the unfavorable kinematic conditions to a discontinuous course of the spring rate on the compression travel.

The mounting of the leaf spring arrangement on the frame element is realized by means of a center bearing arranged between the axes, which is space-consuming and weight-intensive. This can lead to collision hazards of chassis parts with twin tires of the axles, especially when on the

Twin tires snow chains are raised. Furthermore, the position of the

Center bearing unfavorable relative to the frame member, since the center bearing and thus the pivot axis of the leaf spring assembly are positioned relatively far away from the frame member. This has a negative effect on the force application of the spring forces.

Due to unfavorable, high loads and the high number of components, the conventional suspension devices thus have a very high weight.

It is therefore an object of the present invention, a suspension device of a motor vehicle, in particular a commercial vehicle, of the type mentioned in such a way that an improved suspension of the axes of the

Frame element is realized in a particularly weight-favorable manner.

This object is achieved by a suspension device of a motor vehicle, in particular a commercial vehicle, with the features of patent claim 1. Advantageous embodiments with expedient and non-trivial developments of the invention are specified in the remaining claims.

To realize an improved and particularly low-weight suspension of the axles on the frame member, it is provided according to the invention that the

Spring device comprises two spring parts, wherein a first of the spring parts on

Frame member is pivotally supported about a first pivot axis relative to the frame member. The first spring part is assigned to a first of the axes of the tandem axle. This means that the first axle on the first spring part on

Frame element is resiliently supported. The spring device furthermore comprises a second spring part, which is held pivotably on the frame element about a second pivot axis relative to the frame element and which is associated with the second axis. This means that the second axis of the tandem axle is resiliently supported on the frame element via the second spring element.

The spring parts are coupled together via a lever arrangement. The

Swivel axes preferably extend at least substantially in

Vehicle transverse direction and at least substantially parallel to each other.

Due to this configuration of the spring device with the two spring parts, which can pivot or oscillate about their pivot axes during compression and rebound of the axles, the spring device has an improved kinematics or an improved sequence of movements, which leads to an improved efficiency of the particular mechanical axle load compensation , This results, for example, in the field a very good traction of the motor vehicle. Furthermore, the spring rate of the spring device can be advantageously adapted to specific requirements of the tandem axle, which has a positive effect on the ride comfort and the roll behavior of the motor vehicle.

In particular, it is possible, the kinematics or the pendulum movement of the

Spring device advantageously adapt to a kinematics of link elements for guiding the axes, which benefits the advantageous Achslastausgleich and the adjustment of the spring rate.

The described, advantageous connection of the spring parts is possible without the initially described, rigid and weight-intensive center bearing. In other words, the central center bearing and / or a center bearing bracket with connection points for the spring device omitted, resulting in a very low weight of

Suspension device for suspending the axles results. The mechanical axle load compensation is possible in a particularly advantageous manner via the lever arrangement, via which the spring parts are coupled in particular in terms of motion technology.

The lever arrangement preferably represents a movable lever mechanism, which enables a force transmission between the spring parts for realizing an advantageous axle load compensation. The provision of the lever arrangement and the Elimination of the rigid center bearing allows the representation of a very large clearance for tires on the axles. The respective tires move, for example, in a one-sided compression according to the corresponding, oscillating axis, which

is preferably rotatably mounted or connected to a handlebar element, for example in the form of a roll center forming a wishbone.

In a particularly advantageous embodiment of the invention, the first and the second pivot axis are arranged in the vehicle vertical direction at the height of the frame member. This is a direct, frame - side connection of the spring parts at the height of

Created frame element, which benefits in particular the introduction of force. Furthermore, the initially described, weight-intensive center bearing is not required, resulting in a particularly low weight of the suspension device according to the invention.

The spring parts can be formed separately from one another and coupled to one another via a lever element of the lever arrangement. In this case, the lever element, for example, hingedly connected to the respective spring parts. The spring parts can each be formed in one piece. It can be provided that the spring parts are formed of a metallic material. Alternatively and preferably, it is possible that the spring parts of a fiber-reinforced plastic, in particular of a

glass fiber reinforced plastic, are formed. As a result, the spring parts have a very low weight and a particularly advantageous suspension behavior.

The spring parts are integrally formed with each other in another embodiment, wherein the lever assembly is formed integrally with the spring parts. In this case, the spring parts are coupled to each other via the at least one, integrally formed with the spring parts lever member, wherein the lever member is pivotally connected to the spring parts also in the one-piece design relative to the spring parts. This relative movability or pivotability of the at least one lever element of the lever arrangement formed integrally with the spring parts is realized by the spring elasticity of the spring parts formed integrally with one another. In other words, the spring parts have an elasticity, due to which the at least one lever element during pivoting or oscillation of the spring parts about the first and the second pivot axis relative to the spring parts movable or

is pivotable. For advantageous realization of this one-piece design of the spring parts with each other and with the lever arrangement, the at least one lever element is particularly thin-walled, so that it has a particularly advantageous flexibility and can advantageously pivot relative to the spring parts in their commuting.

To illustrate a particularly advantageous suspension of the axes of the

Frame member, the spring parts preferably on a steady-progressive spring rate.

Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments and from the drawing. The features mentioned above in the description and

Characteristic combinations as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures can be used not only in the respectively specified combination but also in other combinations or alone, without departing from the scope of the invention.

The drawing shows in:

Fig. 1 is a schematic side view of a suspension device of a

Motor vehicle in the form of a utility vehicle, with a spring device, via which two in the vehicle longitudinal direction successively arranged axes of a tandem axle are resiliently supported on a frame of the utility vehicle;

2a is a schematic perspective view of another embodiment of the

Suspension device according to Figure 1, wherein the axes are crossed diagonally;

2b is a schematic perspective view of another embodiment of the

Suspension device according to Fig. 2a;

2c is a schematic perspective view of another embodiment of the

Suspension device according to Fig. 1; Fig. 3 in part a schematic side view of

Suspension device according to Fig. 2a;

Fig. 4 is a schematic side view of another embodiment of the

Suspension device according to Figures 1 to 3.

Fig. 5 shows a detail of a schematic side view of another

Embodiment of the suspension device according to FIG. 4; and

6 is a schematic side view of the suspension device according to FIG.

5th

Fig. 1 shows a suspension device 10 of a motor vehicle designed as a utility vehicle. As can be seen in conjunction with FIGS. 2 to 6, the

Suspension device 10 two lateral spring devices 12. One of

Spring devices 12 is arranged on the left side of the utility vehicle, while the other spring device 12 is arranged on the right side.

Two springs 14, 16 of a tandem axle 18 of the commercial vehicle, which are arranged one behind the other in the vehicle longitudinal direction, are resiliently supported by the spring devices 12 on a frame 20 of the utility vehicle. Referring to the image plane of Fig. 1, the forward direction of travel of the utility vehicle runs to the left. The second axle 16 is thus a first rear axle of the commercial vehicle, while the first axle 14 is a subsequent, second rear axle of the utility vehicle. Here are the

Spring means 12 are arranged on the frame 20 such that the spring means 12 are arranged on a respective, lateral frame longitudinal member 22 of the frame 20.

In Fig. 1, one of the spring means 12 is shown. It is understood that the one spring device 12 described readily to the other

Spring device 12 is transferable or applicable.

The spring device 12 comprises a first spring part 24, which is associated with the first axis 14 of the tandem axle 18. The first spring part 24 is a first Swivel axis 26 relative to the longitudinal frame member 22 pivotally connected to a first connection point 28 on the frame side member 22.

The spring device 12 further comprises a second spring part 30 which is associated with the second axis 16 of the tandem axle 18. The second spring part 30 is connected about a second pivot axis 32 relative to the frame longitudinal member 22 pivotally connected to a second connection point 34 on the frame longitudinal member 22.

The spring parts 24, 30 are coupled together via a lever arrangement 36. The lever arrangement 36 comprises a first lever element 38, which is connected to the first spring part 24. The lever assembly 36 further includes a second one

Lever member 40 which is connected to the second spring member 30. In this case, the first lever element 38 is formed by the first spring part 24. In other words, the first spring part 24 and the first lever element 38 are integrally formed with each other, so that the first lever member 38 has resilient properties.

The second lever member 40 is formed by the second spring member 30. In other words, the second spring member 30 and the second lever member 40 are integrally formed with each other, so that the second lever member 40 resilient

Features.

The lever arrangement 36 comprises a third lever element 42 which acts as a coupling of the spring parts 24, 30 acting as deflection springs and via which the lever elements 38, 40 spaced apart from one another in the vehicle longitudinal direction are connected to one another. In this case, the third lever element 42 is pivotable about respective pivot axes 44, 46 relative to the lever elements 38, 40 connected to the lever elements 38, 40. By this coupling of the spring parts 24, 30 is a power transmission between the spring parts 34, 30 and thus a more advantageous, mechanical

Axle load compensation allows.

1, the pivot axes 26, 32 are arranged in the vehicle vertical direction at the level of the longitudinal frame member 22, so that an advantageous and direct introduction of force via the spring device 12 is realized in the frame longitudinal member 22. A space-and weight-intensive center bearing in the vehicle longitudinal direction between the axles 14, 16 is not provided for or to connect the spring means 12 and can be avoided.

The spring parts 24, 30 are made of a metallic material or of a fiber-reinforced plastic, in particular of a glass fiber reinforced plastic. This leads to a particularly advantageous spring behavior of the spring device 12.

As is further illustrated in FIG. 1 by a symmetry axis 48 shown in dashed lines, the spring device 12 is designed to be axially symmetrical with respect to the axis of symmetry 48. In this case, the pivot axes 26, 32 at least substantially equal, respectively distances to the symmetry axis 48.

The respective connection of the spring parts 24, 30 to the axes 14, 16 via a respective tab 50, 51. Here, the first spring member 24 at a third connection point 52 on the first tab 50, wherein the first spring member 24 and the first tab 50th about a third pivot axis 54 are pivotable relative to each other.

As can be seen from FIG. 2 c, a fixed connection of the spring parts 24, 30 to the axles 14, 16 may be provided instead of spring eyes and the tabs 50, 51. As is representative of both spring parts 24, 30 illustrated with reference to FIG. 2c, a receiving element 59 is provided, via which the spring member 30 is connected to the second axis 16.

The second spring part 30 is connected to a second connection point 56 on the second lug 51, wherein the second spring part 30 and the second lug 51 are pivotable about a fourth pivot axis 58 relative to each other. The connection of the spring parts 24, 30 via the tabs 50, 51 allows a path compensation in the vehicle longitudinal direction (x-direction) during oscillation of the spring parts 24, 30 and a change in length at a deflection.

As can be seen in particular FIGS. 2 a and 2 b, the suspension device also includes trailing arm elements 60, 62 as well as triangular link elements 61, 63

Trailing arm elements 60, 62 are each on the one hand at a respective fifth

Junction 64 on the respective axis 14, 16 by a respective fifth Swivel axis 66 (Fig. 3) pivotally connected and in each case on the other hand at a respective sixth connection point 68 connected to a respective sixth pivot axis 70 (Fig. 3) on a bearing block, which preferably must absorb only forces in the vehicle longitudinal direction. This bearing block is not shown and compared to the above-mentioned center bearing, on which conventionally also a leaf spring is supported, much lighter and smaller.

Furthermore, the wishbone elements 61, 63 are each pivotable on a respective seventh connection point 72 about a respective, seventh pivot axis 74 pivotably on the respective axis 14, 16 and on the other hand on respective eighth connection points 76 on the frame longitudinal support elements 22 about a respective, eighth pivot axis 78 tethered.

The trailing arm elements 60, 62 and the wishbone elements 61, 63 serve to guide the axles 14, 16 in the vehicle longitudinal direction (x direction) and in

Vehicle transverse direction (y-direction).

As can be seen in particular in conjunction with FIG. 3, a in

Vehicle longitudinal direction extending, first distance between the first

Connection point 28 and the third connection point 52 of the first spring member 24 and extending in the vehicle longitudinal direction, the second distance between the fifth

Tether 64 and the sixth tether 68 of the first

Trailing arm element 60 at least substantially equal. Further, the first distance and extending in the vehicle longitudinal direction, third distance between the seventh connection point 72 and the eighth connection point 76 of the first

Triangular link element 61 at least substantially equal.

Also, a running in the vehicle longitudinal direction, fourth distance between the second connection point 34 and the fourth connection point 56 of the second spring member 30 and extending in the vehicle longitudinal direction, the fifth distance between the fifth

Tether 64 and the sixth tether 68 of the second

Trailing arm member 62 are at least substantially equal. Also, the fourth distance and a running in the vehicle longitudinal direction, the sixth distance between the seventh attachment point 72 and the eighth attachment point 76 of the second

Triangular link element 63 at least substantially equal. As a result, a particularly advantageous kinematics of the spring device 12 is created. To depict a particularly advantageous kinematics, a first projection of a first straight line connecting the first connection point 28 and the third connection point 52 extends in a plane spanned by the vehicle longitudinal direction and the vehicle vertical direction (z direction) substantially parallel to a second projection of the fifth connection point 64 and the sixth connection point 68 of the first trailing arm element 60 connecting, the second straight line to that of the

Vehicle longitudinal direction and the vehicle vertical direction spanned plane. The first and the second projection also run at least substantially parallel to a third projection of a third, the seventh connection point 72 and the eighth

Connection point 76 of the first wishbone element 61 connecting straight to the plane spanned by the vehicle longitudinal direction and the vehicle vertical direction plane. The same applies to the second attachment point 34 and the fourth attachment point 56 with respect to the fifth attachment point 64 and the sixth attachment point 68 of the second trailing link element 62 and with respect to the seventh attachment point 72 and the eighth attachment point 76 of the second wishbone element 63.

As can be seen in FIGS. 2 a, 5 and 6, the spring parts 24, 30 can also be formed integrally with one another and integrally with the lever arrangement 36. In this case, the third lever element 42 is designed for coupling the spring parts 30, 24 as a particularly thin-walled connecting strap, which due to the elasticity of the one-piece

spring members 24, 30 or their corresponding material formed around the other pivot axes 46, 44 relative to the lever members 38, 40 is pivotable.

The one-piece design of the spring parts 24, 30 together and with the

Lever assembly 36 has the advantage that the suspension device 10 thereby has a particularly low weight. The separate configuration of the spring parts 24, 30 and their connection via the separately formed by the spring parts 24, 30, third lever element 42 allows a particularly simple, time-consuming and cost-effective dimensioning and manufacturing.

In the one-piece design of the spring parts 24, 30 with each other and with the lever assembly 36, the connecting strap can be formed particularly thin-walled, since at least almost exclusively tensile forces are transmitted through them. Tensile forces represent a particularly favorable load case, in particular for fiber-reinforced plastics, since buckling loads and associated problems do not occur.

According to FIG. 1, the lever elements 38, 40 are at least substantially straight, so that, for example, in a relaxed state of the spring device 12, the pivot axes 26, 44 and 32, 46 in the vehicle longitudinal direction at least in

Essentially at a common height. Furthermore, it can be provided that the lever elements 38, 40 extend in the unloaded state obliquely to the vehicle vertical direction, so that the pivot axes 26, 44 and 32, 46 are offset from each other in the vehicle longitudinal direction.

Alternatively, it may be provided that the lever elements 38, 40 are at least substantially arcuate and have at least two adjoining partial areas, which enclose a different angle of 180 ° with each other.

By the pivot axes 26, 32, 44, 46, a four-bar linkage is shown, which allows a parallelogram-like movement of the lever assembly 36 and thus a particularly advantageous kinematics of the spring device 12.

As can be seen in particular Figs. 2b, 4 and 5, can be used to connect the

Spring parts 24, 30 respective connection shoes 80 may be provided, which are presently shown transparent. The spring parts 24, 30 are partially received in the connection shoes 80, wherein the connection shoes 80 to the

Swivel axles 26, 32 are connected to the longitudinal frame member 22 pivotally relative to the frame longitudinal member 22 pivotally.

Instead of the connecting shoes 80, as can be seen in particular from FIG. 2 a, the respective spring part 24, 30 also have further bearing eyes 83, via which the spring parts 24, 30 are connected directly to the frame longitudinal member 22.

FIG. 6 shows a further side view of the suspension device 10 according to FIG. 5, with FIG. 6 particularly clearly showing the one-piece configuration of the spring parts 24, 30 with each other and with the lever arrangement 36. As shown in FIGS. 4 to 6 further to can be seen, the spring parts 24, 30 for connection to the axes 14, 16 respective bearing lugs 82.

Are the spring parts 24, 30 - as shown in Fig. 4 - formed separately from each other and coupled to each other via the separately formed by the spring members 24, 30, the third lever member 42, the spring members 24, 30 preferably further bearing lugs 84 on which the third lever element 42 about the further pivot axes 44, 46 relative to the spring parts 24, 30 is pivotally mounted on the spring parts 24, 30 or on the lever elements 38, 40.

If the third lever element 42 is formed separately from the spring parts 24, 30, the third lever element 42 is formed, for example, from a different material than the spring parts 24, 30. This keeps, for example, the cost of the suspension device 10 low.

The pivot axes 26, 32, 54, 58, 74 extend at least substantially in

Vehicle transverse direction and thus at least substantially parallel to each other, while the eighth pivot axes 78 extend obliquely thereto.

The corresponding embodiment of the suspension device 10 and in particular of the spring device 12 leads to a particularly advantageous kinematics of the spring parts 24, 30, resulting in very good driving dynamics characteristics of the utility vehicle. These are very good driving dynamics characteristics on special

created weight-favorable manner, since the spring means 12 and thus the entire suspension device 10 has a very low weight.

Claims

Daimler AG claims

1. suspension device (10) of a motor vehicle, with at least one arranged on a frame member (22) of the motor vehicle spring means (12) via which two in the vehicle longitudinal direction successively arranged axes (14, 16) of a tandem axle (18) of the motor vehicle on the frame element (22 ) are resiliently supported,

characterized in that

the spring means (12) on the frame member (22) about a first

Pivot axis (26) pivotally held and a first of the axes (14, 16) associated, first spring member (24) and on the frame member (22) about a second pivot axis (32) pivotally mounted and the second axis (16) associated second spring member (30), wherein the spring parts (24, 30) via a lever arrangement (36) are coupled together.

2. Suspension device (10) according to claim 1,

characterized in that

the lever arrangement (36) comprises a first lever element (38) associated with the first spring part (24) and a second lever element (40) associated with the second spring part (30), wherein the first and the second lever element (38, 40) engage in the Extend substantially in the vehicle vertical direction away from the respective spring part (24, 30) and are coupled to one another via a third lever element (42) of the lever arrangement (36) which extends substantially in the vehicle longitudinal direction.

3. suspension device (10) according to claim 2,

characterized in that

the first lever element (38) is formed integrally with the first spring part (24) and the second lever element (40) is formed integrally with the second spring part (30). Suspension device (10) according to one of claims 2 or 3,

characterized in that

the third lever element (42) is formed integrally with the first and the second lever element (38, 40).

Suspension device (10) according to one of the preceding claims, characterized in that

the first spring part (24) is connected to the first axis (14) at a first connection point (52) and to the frame element (22) at a second connection point (28), the suspension device (10) being connected at least at one end to a third connection point (10). 72) on the first axis (14) about a third pivot axis (74) pivotally connected and on the other hand at a fourth connection point (76) on the frame member (22) about a fourth pivot axis (78) pivotally connected handlebar element (61, 63) for guiding the first axis (14), and wherein a running in the vehicle longitudinal direction, the first distance between the first and the second connection point (28, 52) and extending in the vehicle longitudinal direction, the second distance between the third and the fourth connection point (72, 76) in Are essentially the same.

Suspension device (10) according to claim 5,

characterized in that

a first projection of a first straight line connecting the first and the second connection points (28, 52) in a plane spanned by the vehicle longitudinal direction and the vehicle vertical direction, substantially parallel to a second projection of a connecting the third and fourth connection points (72, 76), second straight in the plane defined by the vehicle longitudinal direction and the vehicle vertical direction plane.

the first and the second pivot axis (26, 32) in the vehicle vertical direction at the height of the frame member (22) are arranged.