DE102017201277A1 - Transverse leaf spring for an axle of a vehicle, axle for a vehicle and vehicle - Google Patents

Abstract

The invention relates to a transverse leaf spring (10) for an axle (100) of a vehicle, in particular for an axle (100) of a two-lane motor vehicle, an axle (100) for a vehicle and a vehicle, the transverse leaf spring (10) each having two outer regions (1), a central region (3) and two, each between the central region (3) and an outer region (1) arranged intermediate regions (2), wherein the two outer regions (1), the wheel-side end portions of the transverse leaf spring (10 ) and the middle region (3) has a vehicle body-side attachment region, wherein the two outer regions (1) or the intermediate regions (2) are respectively flexible in the vehicle vertical direction (Z) and in the vehicle transverse direction (Y) and / or in the vehicle longitudinal direction (X). are rigid, and wherein the two intermediate regions (2) or the two outer regions (1) in each case in the vehicle longitudinal direction (X) are flexible and in vehicle toe direction (Z) and / or in the vehicle transverse direction (Y) are stiff.

Description

The invention relates to a transverse leaf spring for an axle of a vehicle, in particular for an axle of a two-lane motor vehicle. Furthermore, the invention relates to an axle for a vehicle, in particular an axle for wheels of a two-lane motor vehicle and a vehicle having such an axle.

Axes with a transverse leaf spring, ie with a substantially extending in the vehicle transverse direction leaf spring, are basically known from the prior art, for example. From the DE-AS 1 028 436 , of the DE 25 41 841 , of the DE-PS 937 391 , of the DE 41 40 236 A1 or the DE 10 2007 051 470 A1 ,

Such transverse leaf spring axles are particularly suitable for axles which are constructed on the principle of a strut axle, in particular for axles which are constructed on the principle of a MacPherson strut axle, i. with respectively wheel-side supported in the wheel carrier dampers, which instead of a shock absorber only have a damper strut, i. which have no arranged around the damper strut coil spring.

The spring function can be taken over by the transverse leaf spring in this case. That the coil spring, which is often referred to as a suspension spring, can be omitted. As a result, considerable space advantages can be achieved.

Depending on the connection of the transverse leaf spring within the axis, the transverse leaf spring acts wheel guiding or not radführend, occurring at wheel-guiding transverse leaf springs, in particular introduced via the wheels of the axle forces can be supported on the transverse leaf spring, while non-wheel-guiding transverse leaf springs are mounted accordingly yielding. In particular, a distinction is made laterally wheel-guiding or laterally non-wheel-guiding transverse leaf springs and in the vehicle longitudinal direction wheel-guiding or in the vehicle longitudinal direction non-wheel-leading transverse leaf springs, i. Transverse leaf springs which support transverse or lateral forces occurring or are resiliently mounted in the vehicle transverse direction, and transverse leaf springs support the longitudinal forces occurring or are resiliently mounted in the vehicle longitudinal direction.

From the DE 41 40 236 A1 as well as from the DE 25 41 841 in each case a transverse leaf spring axis for a two-lane motor vehicle is known, which has a laterally and longitudinally wheel-guiding, supported in two spaced-apart points on the vehicle body transverse leaf spring, the transverse leaf spring with their ends, ie wheel carrier side, each stiff, in particular dimensionally stable, at a lower Wishbone is tied. That is, the transverse leaf spring connects the left lower arm to the right lower arm of the axle.

From the DE 10 2007 051 470 A1 shows that the support of the lateral forces on the vehicle body can be achieved via the transverse leaf spring by the transverse leaf spring is connected to support the lateral forces acting on two eccentric, almost rigid in the vehicle transverse direction bearing on the vehicle body and on the other such tied or supported so stiff on the wheel , For example, by a fixed screw by means of one or more screws or via a coupling element in the form of a corresponding rubber bearing that acts like a transverse link and thus is radführend sideways and also acts radführend in the longitudinal direction by the rigid connection of the leaf spring in the vehicle longitudinal direction.

However, the rigid connection of the transverse leaf spring has the disadvantage that in particular the so-called longitudinal spring rate in the vehicle longitudinal direction is very high, which usually has a disadvantageous effect on the ride comfort.

The obvious solution, the transverse leaf spring in the vehicle longitudinal less rigid, for example by means of suitably soft trained rubber bearing, but in many cases does not lead to the desired effect, since the rubber bearing is biased by the high, occurring during driving vertical loads such that the to achieve the desired comfort properties required in the vehicle longitudinal direction "softness" can not be achieved.

To solve this problem proposes the EP 1 080 953 A1 in each case a spring arm to be arranged at each end of the transverse leaf spring, which is force-transmitting, in particular non-positively connected to the transverse leaf spring and is supported on the vehicle body, wherein the spring arms in particular point to the vehicle longitudinal center plane and at an acute angle to the transverse leaf spring longitudinal direction and in particular can be made in one piece. By the spring arms, a particularly good support of the longitudinal forces can be achieved. In order to be able to support the largest possible proportion of the longitudinal forces on the spring arms and not on the actual transverse leaf spring, the transverse leaf spring may have a constriction, by means of which the longitudinal stiffness of the transverse leaf spring can be reduced, whereby the longitudinal forces can be amplified absorbed by the spring arms.

The DE 10 2014 225 884 A1 suggests to achieve the desired compliance in the vehicle longitudinal direction using the transverse leaf spring a special connecting element to be fastened to the wheel carrier, wherein the connecting element between the connection to the wheel carrier and the connection to the transverse leaf spring has a flexible in the vehicle longitudinal direction and / or in the vehicle vertical direction and / or in the vehicle transverse direction stiff intermediate region which is in particular designed as a bending beam and thus the Compliance in the vehicle longitudinal direction guaranteed.

In addition, from the DE 10 2011 083 227 A1 known to adjust the spring behavior of a transverse leaf spring using the curvature and on the size of the cross section of the transverse leaf spring, wherein the DE 10 2011 083 227 A1 in particular proposes a transverse leaf spring, the areas of different curvatures and / or cross-sectional geometries for setting the desired spring behavior, although only described how the spring behavior in the vertical direction, ie in the vehicle vertical direction, based on a functional installation state of the transverse leaf spring, can be optimized.

Against this background, it is an object of the invention to provide an alternative transverse leaf spring, in particular a transverse leaf spring, with which without additional elements such as spring arms or specially designed connection elements a desired spring behavior both in vehicle vertical direction and / or vehicle transverse direction and in the vehicle longitudinal direction, based on a functional installation state of the transverse leaf spring in a vehicle, can be achieved. Furthermore, it is an object of the invention to provide a corresponding axle for a vehicle with a transverse leaf spring and a vehicle with such an axle.

This object is achieved by a transverse leaf spring with the features of claim 1 , by an axle with the features of claim 7 and by a vehicle having the features of claim 8. Advantageous and preferred embodiments of the invention are subject matter of further claims and are explained in more detail below. The wording of the claims is incorporated herein by express reference. Some of the features mentioned below, in order to avoid repetition, sometimes only described once, ie only in connection with a transverse leaf spring according to the invention, an axle according to the invention or a vehicle according to the invention, but apply regardless of both the transverse leaf spring and the axis and for the Vehicle.

An inventive transverse leaf spring for an axle of a vehicle, in particular for an axle of a two-lane motor vehicle, each has two outer regions, a central region and two, each between the central region and an outer region disposed intermediate regions, wherein the two outer regions of the wheel-side end portions form the transverse leaf spring and the central region of a vehicle body-side connection region, wherein the two outer regions or the two intermediate regions are each formed flexible in the vehicle vertical direction and stiff in the vehicle transverse direction and / or in the vehicle longitudinal direction, and wherein the two intermediate regions or the two outer regions respectively Vehicle longitudinal direction are designed to be flexible and rigid in the vehicle vertical direction and / or in the vehicle transverse direction, each based on a functional installation state of the transverse leaf spring in a vehicle ,

With such a transverse leaf spring, both the desired spring properties in the vertical direction, i. in the vertical direction of the vehicle, as well as a sufficient support of occurring transverse or lateral forces in the vehicle transverse direction as well as a required to achieve a pleasant ride comfort in the vehicle longitudinal direction compliance.

In an advantageous embodiment of a transverse leaf spring according to the invention, the two outer regions are each flexible in the vehicle vertical direction and formed stiff in the vehicle transverse direction and / or in the vehicle longitudinal direction, wherein preferably the two intermediate regions are each formed flexible in the vehicle longitudinal direction and stiff in vehicle vertical direction and / or in the vehicle transverse direction are.

In a further advantageous embodiment of a transverse leaf spring according to the invention an expansion of the transverse leaf spring in at least one intermediate region at least partially in the vehicle vertical direction is greater than in the vehicle longitudinal direction, based on a functional installation state of the transverse leaf spring in a vehicle. As a result, the required flexibility in the vehicle longitudinal direction in the intermediate region can be achieved in a particularly simple manner. About the ratio of the extension of the transverse leaf spring in the vehicle vertical direction for extending the transverse leaf spring in the vehicle longitudinal direction in the intermediate region, the spring rate in the vehicle longitudinal direction can be adjusted accordingly.

In a further advantageous embodiment of a transverse leaf spring according to the invention, the extent of the transverse leaf spring in at least one outer region in the vehicle longitudinal direction is at least partially greater than in the vehicle vertical direction, based on a functional installation state of the transverse leaf spring in a vehicle. This can In a simple manner, the desired spring behavior, in particular in the vertical direction, ie in the vehicle vertical direction, can be achieved in the outer region. By means of the ratio of the extent in the vehicle longitudinal direction to the extent in the vehicle vertical direction, the spring rate in the vertical direction can be adjusted accordingly.

In a further advantageous embodiment of a transverse leaf spring according to the invention, the transverse leaf spring in the central region has a constriction, in particular in the vehicle vertical direction and / or in the vehicle longitudinal direction, based on a functional installation state of the transverse leaf spring in a vehicle. As a result, in addition to the pure spring function with the transverse leaf spring, the function of a stabilizer can also be represented, which serves for roll support with opposite compression of the wheels of an axle and counteracts rotation of the vehicle about the longitudinal axis.

In a further advantageous embodiment of a transverse leaf spring at least an outer region of the transverse leaf spring is at least partially formed like a wishbone or a rocker and preferably supported like a wishbone or a rocker via at least two effective kinematic points on the suspension of a vehicle, in particular at two effective kinematic points on a Wheel carrier and / or on one or more wheel-guiding links and / or at least one effective kinematic point on the vibration damper. In this way, a particularly advantageous connection of the transverse leaf spring to the suspension of a vehicle can be achieved. In some cases, it is advantageous if the transverse leaf spring can be connected to the wheel. In other cases, it is more advantageous if the transverse leaf spring can be connected to one or more wheel-guiding links and in yet other cases a connection of the transverse leaf spring is particularly advantageous, at least with a kinematic point on the vibration damper.

A transverse leaf spring according to the invention is preferably formed in one piece. In some cases, it may also be more advantageous if the transverse leaf spring is formed in several parts, in which case preferably the individual areas are each integrally formed and connected to each other at the transition areas, in particular by means of a suitably formed connecting element, preferably by means of a sleeve-like connecting element ,

Preferably, the transverse leaf spring is designed such that the cross-sectional profile over the entire length of the transverse leaf spring is continuous and in particular does not change abruptly. As a result, stress peaks can be avoided under load.

Preferably, a transverse leaf spring according to the invention is made of a fiber composite material, in particular of CFRP, i. a carbon fiber reinforced plastic, or fiberglass, i. made of a glass fiber reinforced plastic. In some cases, the desired spring properties can also be achieved with a transverse leaf spring made of metal, in particular with a transverse leaf spring made of steel.

Preferably, the transverse leaf spring is adapted to be connected in a conventional, known from the prior art manner with a suspension and / or a vehicle body, in particular via corresponding bearings. As the connection of the transverse leaf spring can be configured, in particular in an axis according to the invention, for example, the DE-PS 937 391 or the DE-AS 1 028 436 or the WO 2011/023546 A2 be removed. A particularly suitable connection of a transverse leaf spring in an axle for a two-lane motor vehicle is in the DE 10 2014 223 576 A1 described, to which hereby expressly referred.

An axle according to the invention for a vehicle, in particular an axle according to the invention for wheels of a two-lane motor vehicle, has a transverse leaf spring according to the invention.

An inventive vehicle, in particular a two-lane motor vehicle according to the invention, has an axle according to the invention with a transverse leaf spring according to the invention.

These and other features will become apparent from the claims and from the description also from the drawings, wherein the individual features in each case alone or more in the form of sub-combinations in one embodiment of the invention be realized and represent advantageous and inherently protectable versions if this makes sense technically.

In the following the invention with reference to three preferred embodiments will be further explained, the invention being schematically illustrated in the accompanying drawings. 1a shows schematically a first embodiment of an inventive axis with a first embodiment of a transverse leaf spring according to the invention in plan view, 1b the axis off 1a in view from behind, 2 A second embodiment of an axle according to the invention with a second embodiment of a Inventive transverse leaf spring in view from behind and 3 a third embodiment of an inventive axle with a third embodiment of a transverse leaf spring according to the invention, also in view from behind.

Essential to the invention may be all of the features described, as well as all features shown.

1 shows a first embodiment of an inventive axle 100 for a two-lane motor vehicle with a first embodiment of a transverse leaf spring according to the invention 10 in plan view, the axis 100 here only by the two wheels 5 , which are connected to the axis, is shown symbolically. In particular, no other components of the axle such as wheel-guiding arm, the wheel or vibration or the like are shown.

The transverse leaf spring 10 the axis according to the invention 100 is in this embodiment, on the one hand with their wheel carrier ends in each case via a first effective kinematic point K1 attached to a wheel carrier, not shown here and two conventional, known from the prior art bearings 4 attached to the vehicle body or the body, which is also not shown here.

According to the invention, the transverse leaf spring 10 different areas 1 . 2 and 3 in which the transverse leaf spring 10 in terms of their rigidity in the individual spatial directions X (Vehicle longitudinal direction), Y (vehicle transverse direction) and Z (vehicle vertical direction), based on a functional installation state in a vehicle or an axle of a vehicle, is designed differently. According to the invention, the transverse leaf spring 10 in each case two outer areas 1 , a middle area 3 and two, each between the middle area 3 and the two outer regions 1 arranged intermediate areas 2 on, wherein the two outer regions 1, the wheel-side end portions of the transverse leaf spring 10 form and the middle area 3 a vehicle body-side connection area.

In this embodiment of a transverse leaf spring according to the invention 10 are the two outer areas 1 each in the vehicle vertical direction Z flexibly formed and in the vehicle transverse direction Y and in the vehicle longitudinal direction X stiff. The two intermediate areas 2 are each in the vehicle longitudinal direction X flexibly formed and in vehicle vertical direction Z and formed in the vehicle transverse direction according to stiff. With such a trained, transverse leaf spring according to the invention 10 can in a simple way the desired spring properties in the vertical direction Z , ie in the vehicle vertical direction Z , A sufficient support of lateral or lateral forces in Y, ie in the vehicle transverse direction Y , as well as one to achieve a pleasant ride comfort in the vehicle longitudinal direction X required compliance can be achieved.

The different stiffness or flexibility of the individual areas 1 . 2 and 3 in each case by the geometry of the transverse leaf spring 10 in the individual areas 1 . 2 and 3 achieved, in particular by different cross-sectional geometries in these areas 1 . 2 and 3 ,

In this case, the two outer areas point 1 in the vehicle longitudinal direction X each greater extent than in the vehicle vertical direction Z as based on the 1a and 1b it is easy to see where 1b the axis off 1a in view from behind shows. The cross section of the outer regions is preferably rectangular, at least except for a transition region to the adjacent intermediate region. As a result, in a particularly simple manner, the corresponding rigidity in the vehicle longitudinal direction Z as well as in the vehicle transverse direction Y be reached, with appropriate compliance in the vehicle vertical direction Z or in vertical direction Z ,

The intermediate area 2 as well as the middle area 3 on the other hand point in vehicle vertical direction Z a greater extent than in the vehicle longitudinal direction X, wherein the intermediate areas 2 as well as the middle area 3 preferably also have a substantially rectangular cross-section.

For a harmonious force or bending over the length of the transverse leaf spring 10 in vehicle transverse direction Y changes the cross section of the transverse leaf spring 10 along its length, ie in the vehicle transverse direction Y , preferably steadily, as indicated in particular by 1b can be clearly seen, so that spikes and thus a discordant spring behavior, which would adversely affect the ride comfort and driving characteristics, can be avoided.

2 shows a second embodiment of an inventive axis 200 with a second embodiment of a transverse leaf spring according to the invention 20 , also in rear view, with the transverse leaf spring 20 to the effect of the previously using the 1a and 1b described transverse leaf spring 10 distinguishes that the transverse leaf spring 20 in the middle area 3 a constriction 6 in vehicle vertical direction Z having. As a result, with the transverse leaf spring according to the invention 20 not only a spring function can be realized, but also a stabilizer function. That is, with the transverse leaf spring according to the invention 20 can at mutual or opposite compression of the two wheels 5 In addition, a roll support can be achieved.

3 shows a third embodiment of an inventive axis 300 with a third embodiment of a transverse leaf spring according to the invention 30 , also in view from behind, with this transverse leaf spring 30 to the effect of the two previously described transverse leaf springs 10 and 20 distinguishes that the two outer regions 1 are formed like a rocker and two kinematics points K1 and K2 are connected to the suspension, in which case the transverse leaf spring 30 each over the first kinematic point K1 and the second kinematic point K2 on the wheel carrier of the axle 300 is hinged.

Another difference is that the two intermediate areas 2 have no substantially rectangular cross-section, but in addition still a slight curved course over the length of the transverse leaf spring 30 in vehicle transverse direction Y to achieve the desired spring behavior.

All of the above transverse leaf springs 10 . 20 and 30 are each made of a fiber-reinforced plastic, in particular made of carbon fiber reinforced plastic and in particular in one piece, ie the individual areas 1 . 2 and 3 are each integrally formed with each other and go with a continuous cross-sectional profile into each other.

Of course, a variety of modifications, in particular to structural modifications, to the illustrated embodiments possible without departing from the content of the claims.

LIST OF REFERENCE NUMBERS

100, 200, 300

inventive axis

10, 20, 30

Inventive transverse leaf spring

1

outer area

2

intermediate area

3

middle area

4

Bearing for connecting the transverse leaf spring to the vehicle body

5

wheel

6

constriction

K1

first kinematics point

K2

second kinematic point

X

Vehicle longitudinal direction

Y

Vehicle transverse direction

Z

Vehicle vertical direction

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 1028436 [0002, 0025]
• DE 2541841 [0002, 0006]
• DE 937391 [0002, 0025]
• DE 4140236 A1 [0002, 0006]
• DE 102007051470 A1 [0002, 0007]
• EP 1080953 A1 [0010]
• DE 102014225884 A1 [0011]
• DE 102011083227 A1 [0012]
• WO 2011/023546 A2 [0025]
• DE 102014223576 A1 [0025]

Claims (8)

A transverse leaf spring (10, 20, 30) for an axle (100, 200, 300) of a vehicle, in particular for an axle (100, 200, 300) of a two-lane motor vehicle, the transverse leaf spring (10, 20) each having two outer regions (1 ), a central region (3) and two, each between the central region (3) and an outer region (1) arranged intermediate regions (2), wherein the two outer regions (1) form the wheel-side end portions of the transverse leaf spring (10) and the middle region (3) has a vehicle body-side attachment region, wherein the two outer regions (1) or the two intermediate regions (2) are each flexible in the vehicle vertical direction (Z) and rigid in the vehicle transverse direction (Y) and / or in the vehicle longitudinal direction (X) are formed, and wherein the two intermediate regions (2) or the two outer regions (1) in each case in the vehicle longitudinal direction (X) are flexible and in the vehicle vertical direction (Z) and / or in Fahrzeugquerrichtu ng (Y) are stiff, in each case based on a functional installation state of the transverse leaf spring (10, 20) in a vehicle. Transverse leaf spring (10, 20, 30) after Claim 1 , characterized in that the two outer regions (1) in the vehicle vertical direction (Z) are flexible and in the vehicle transverse direction (Y) and / or in the vehicle longitudinal direction (X) are stiff, preferably wherein the two intermediate regions (2) each in the vehicle longitudinal direction (X) are flexible and in the vehicle vertical direction (Z) and / or in the vehicle transverse direction (Y) are stiff, each based on a functional installation state of the transverse leaf spring (10, 20) in a vehicle. Transverse leaf spring (10, 20, 30) after Claim 1 or 2 , characterized in that an extension of the transverse leaf spring (10, 20, 30) in at least one intermediate region (2) at least partially in the vehicle vertical direction (Z) is greater than in the vehicle longitudinal direction (X), based on a functional installation state of the transverse leaf spring (10, 20, 30) in a vehicle. Transverse leaf spring (10, 20, 30) according to at least one of the preceding claims, characterized in that the extension of the transverse leaf spring (10, 20, 30) in at least one outer region (1) in the vehicle longitudinal direction (X) is at least partially greater than in the vehicle vertical direction (Z), based on a functional installation state of the transverse leaf spring (10, 20, 30) in a vehicle. Transverse leaf spring (20) according to at least one of the preceding claims, characterized in that the transverse leaf spring (20) in the central region (3) has a constriction (6), in particular in the vehicle vertical direction (Z) and / or in the vehicle longitudinal direction (X), based on a functional installation state of the transverse leaf spring (20) in a vehicle. Transverse leaf spring (30) according to at least one of the preceding claims, characterized in that at least an outer region (1) of the transverse leaf spring (30) is at least partially formed as a wishbone or a rocker and preferably as a wishbone or a rocker over at least two effective kinematics (K1, K2) can be supported on the wheel suspension of a vehicle, in particular on two effective kinematic points (K1, K2) on a wheel carrier and / or on one or more wheel-guiding links and / or with at least one effective kinematic point (K1, K2) on the vibration damper , Axle (100, 200, 300) for a vehicle, in particular axle (100, 200, 300) for wheels of a two-lane motor vehicle, wherein the axle (100, 200, 300) has a transverse leaf spring (10, 20, 30), characterized in that the transverse leaf spring (10, 20, 30) according to at least one of Claims 1 to 6 is trained. Vehicle, in particular two-lane motor vehicle, having an axis (100, 200, 300) with a transverse leaf spring (10, 20, 30), characterized in that the axis (100, 200, 300) according to Claim 7 is trained.

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