DE102017211277B4 - Wheel suspension for a motor vehicle - Google Patents

Abstract

Wheel suspension (1) for a motor vehicle, with a wheel carrier (2) to which a shock absorber (5) and a link (8) are pivotably connected, the shock absorber (5) and the link (8) being independently of one another about a common, axially running pivot axis (S) can be pivoted relative to the wheel carrier (2), characterized in that the wheel carrier (2), the shock absorber (5) and the link (8) are mounted together on an axle body (14.1) that defines the pivot axis (S). one of the components wheel carrier (2), shock absorber (5) and link (8) is mounted on the axle body (14.1) via a single bearing (2.1), while the other two each have a bearing formed on a fork section (7.1, 8.1). Double bearings (7.2, 7.3, 8.2, 8.3) are mounted axially on both sides of the single bearing (2.1) on the axle body (14.1).

Description

The invention relates to a wheel suspension for a motor vehicle having the features of the preamble of claim 1.

The closest to the invention DE 41 08 164 A1 discloses a wheel suspension for the driven rear wheels of a motor vehicle with a wheel carrier supported on the body via a spring strut, which is guided via two individual links forming an upper linkage and a lower linkage consisting of a triangular linkage and a tie rod linkage running approximately in the transverse direction of the vehicle, with the individual links in the transverse direction of the vehicle are arranged diverging and are mounted in two spaced joints of the wheel carrier and the wishbone is held on the wheel carrier via a joint and both linkages have an elastokinematic wheel pivot axis located on the outside of the wheel with one - in relation to the direction of travel - lying behind the vertical wheel center transverse plane and outside the vertical wheel center longitudinal plane form the steering pole in the wheel contact plane, with the two linkages - with reference to the direction of travel - arranged in inclined planes that rise obliquely forward and are set at an angle to one another, and in these planes spaced handlebar rotation axes are formed by the body-side joints of the two linkages, which viewed from the side and in the direction of travel at different angles to the wheel contact area and - viewed from above - are arranged crossed at an angle to one another, and that the wheel carrier-side joints of the two articulations opposite the two pivot axes of the handlebars are close to a vertical wheel center transverse plane and directly adjacent to a vertical wheel center longitudinal plane and that the body-side joints of the two linkages have a differently defined radial identifier for pivoting in the direction of toe-in around the front joint of the lower linkage.

In modern motor vehicles, all the wheels are connected to the body or the chassis of the vehicle via a suspension system. The respective wheel and a wheel carrier that accommodates it are part of the unsprung mass, which more or less follows the height of the respective driving surface, while the body and chassis form parts of the sprung mass, which should be at least largely decoupled from sudden movements of the unsprung mass. The effect of the springs is supplemented by shock absorbers, which convert the energy of the movement between the sprung and unsprung masses into heat and thus prevent unwanted vibrations. Since the movement of the sprung mass relative to the unsprung mass is predominantly vertical, the orientation of the springs and shock absorbers also deviates only slightly from the vertical. In addition, the wheel carrier is connected to the chassis by more or less horizontally running links (e.g. wishbones or trailing arms). In addition to wheel suspensions in which the spring is at least indirectly connected to the wheel carrier, such designs are also known in which the spring acts on a link. The same applies to the shock absorber. The spring can surround the shock absorber concentrically or can be arranged offset to it. In order to be able to follow the movements of the wheel carrier guided by the links, the angle of inclination of the shock absorber relative to the vertical often has to change. It must therefore be pivotable on the wheel carrier or on a handlebar.

With the suspension, as with all components of the vehicle, there is a general desire to reduce overall weight, simplify assembly and save costs. At least some, if possible all of the stated objectives should be realized at the same time.

The JP H11-222 153 A shows a wheel suspension with a wheel carrier, which is connected to the vehicle body via a lower wishbone. The connection to the wishbone is provided by a rubber-metal composite bearing. At a distance from this, the wishbone has an axle mount running in the X-direction for a pivot axis, by means of which a damper tube of a shock absorber is pivotably connected to the wishbone.

The CN 102 216 094 B shows a wheel suspension in which a wheel carrier is connected to a vehicle body via various links. Furthermore, a shock absorber is connected to the wheel carrier via a pivot axis running in the Y direction. In addition, means for adjusting the torsional rigidity are interposed between the shock absorber and the wheel carrier.

The JP 2 931 670 B2 discloses a wheel suspension with a wheel carrier which is connected to the vehicle body via a lower wishbone and an upper link arrangement. The upper link arrangement comprises a plurality of elements which are connected to one another in an articulated manner and is connected via a rocker element to a lower end of a spring-damper element and to the lower wishbone.

The U.S. 2010/0 117 318 A1 shows a wheel suspension with a wheel carrier, which is connected to a vehicle body via a lower wishbone and an upper wishbone. A shock absorber is passed through the upper wishbone and is pivotally connected at a lower end to the lower wishbone. In the area of the connection, the shock absorber has a fork section which is articulated to the lower wishbone at two points spaced apart in the X-direction. A similar arrangement is from U.S. 2010/0 094 503 A1 known.

The CN 203 511 209 U shows a suspension unit with a wishbone that has a receptacle on which a damper spring is mounted. Furthermore, a stabilizer is connected in an articulated manner to the wishbone via a vertically extending coupling rod.

The DE 10 2010 043 428 A1 discloses a wheel suspension for a vehicle, with at least one wishbone which is pivotably connected to a vehicle body by means of one or more bearings, a steering knuckle which is movably connected to the wishbone by means of a joint, and a vehicle wheel rotatably mounted on the steering knuckle. The wishbone comprises a plurality of wishbone parts that can be adjusted relative to one another, of which a first wishbone part is fixedly connected to the bearing or bearings and a second wishbone part is fixedly connected to the joint.

The U.S. 7,537,223 B2 describes a suspension assembly for a vehicle wheel with a wheel carrier unit, a wishbone that is articulated to the wheel carrier unit and a chassis, and at least one actuator that is connected to the chassis and the wheel carrier unit to face the wheel carrier unit to adjust the chassis. In order to reduce transverse loading of the actuator by the wheel carrier, a connection arrangement between the wheel carrier and the chassis is provided in the vicinity of the actuator.

The DE 102 49 119 B4 discloses a damper strut wheel suspension for vehicles with a shock absorber, the lower end of the damper tube is connected to a wheel carrier and the piston rod of which is ultimately supported with its free end on the vehicle body, and with a wishbone articulated on the wheel carrier, which carries a spring element supporting the body. The spring element is supported on the end area of a rocker which is mounted on the wishbone and which acts on a lever arm of the damper tube with its other end area which is opposite in relation to a rocking axis. This causes a compensating moment, which partially compensates for a bending moment acting on the shock absorber due to the vertical wheel force.

In view of the state of the art presented, various aspects of a wheel suspension, such as complexity, cost, weight, number of parts and effort during assembly, still offer room for improvement.

The object of the invention is to provide a wheel suspension which is optimized in terms of weight, costs and/or assembly effort.

According to the invention, the object is achieved by a wheel suspension with the features of claim 1.

A wheel suspension for a motor vehicle is shown, with a wheel carrier to which a shock absorber and a link are pivotably connected, the shock absorber and the link being pivotable independently of one another about a common, axially extending pivot axis relative to the wheel carrier. According to the invention, the wheel carrier, the shock absorber and the link are mounted together on an axle body that defines the pivot axis, with one of the wheel carrier, shock absorber and link components being mounted on the axle body via a single bearing, while the other two are each mounted axially on both sides via a double bearing formed on a fork section of the single bearing are mounted on the axle body.

The dependent claims relate to advantageous developments of the invention.

It should be pointed out that the features and measures listed individually in the following description can be combined with one another in any technically meaningful way and show further refinements of the invention. The description additionally characterizes and specifies the invention, in particular in connection with the figures.

The invention provides a wheel suspension for a motor vehicle. Cars or trucks in particular come into consideration here as motor vehicles. It can be the suspension of a front wheel or rear wheel. The wheel suspension has the wheel carrier to which the shock absorber and the link are pivotably connected. The wheel carrier or steering knuckle is provided in a known manner to accommodate a wheel which is thus rotatably mounted with respect to the same in the installed state. The shock absorber is also used in a known manner to dampen vibrations of the sprung mass against the unsprung mass. He can basically take on any structural form known in the state of the art, for example it can be in the form of a hydraulic shock absorber. The link, which can also be referred to as the suspension link, is connected at least indirectly to the vehicle body in the assembled state, with "vehicle body" being used here as a collective term for the body, the chassis and possibly a subframe. The handlebar serves (usually together with other handlebars) to guide the wheel carrier and thus the wheel. In principle, it can be any type of link, for example a trailing link, semi-trailing link or wishbone. Likewise, it may be an upper or lower link, although it is usually a lower link for reasons to be explained below. There are no restrictions within the scope of the invention with regard to the materials of the wheel carrier and wishbone. Typically, the components can be made of metal, for example steel, aluminum or gray cast iron. In addition, however, composite materials such as fiber-reinforced plastic can also be used.

Both the shock absorber and the handlebar are pivotably connected to the wheel carrier. On the other hand, a pivotable connection to the vehicle body is normally provided for both the shock absorber and the link, so that the wheel carrier can move as a whole relative to the vehicle body during compression. The pivotability of the shock absorber usually means that it is not aligned vertically, but at an angle to the vertical, which typically increases with increasing deflection. Normally, however, the shock absorber occupies a smaller angle with respect to the vertical than the handlebars, which, depending on the deflection state of the wheel, can be aligned approximately or even exactly horizontally.

As already mentioned, the wheel suspension can have other components such as e.g. B. have more handlebars. In addition, at least one spring is generally provided, which can be designed as a helical spring, for example. Such a spring can be supported on the one hand on the vehicle body and on the other hand either on the wheel carrier or on one of the handlebars.

As already mentioned above, the shock absorber and the link can be pivoted independently of one another about a common, axially running pivot axis with respect to the wheel carrier. The axial direction is defined by the course of the pivot axis. That is, if you consider the pivot axis as a geometric object with unlimited length, the pivot axis of the shock absorber is identical to that of the link. This generally reduces the installation space required for the wheel suspension, since the respective pivot axes do not have to be offset transversely to their direction (ie, for example, in the direction of the Z-axis of the vehicle). This can also bring advantages in terms of weight and the complexity of the wheel carrier, since the force is introduced by the shock absorber and the link at least approximately in the same area of the wheel carrier, which can be advantageous compared to a force introduction in two different areas, which would have to be structurally reinforced accordingly. The structure described here benefits from the fact that the shock absorber and the link normally extend at significantly different angles with respect to the vertical, which means that a collision between the two components is largely ruled out.

The pivot axis preferably runs parallel to the X-axis of the motor vehicle, with the link being designed as a wishbone. This is advantageous in that lateral pivoting of the shock absorber (i.e. within the Y-Z plane) is preferred. Furthermore, the wishbone is preferably designed as a lower wishbone, since in this case (in the vertical direction) there is more installation space for the shock absorber.

There are different possibilities with regard to the physical realization of the common pivot axis. For example, an axle pin or the like could be formed on the wheel carrier or one of the other two elements or attached in some other way, e.g. B. welded. According to the invention, the wheel carrier, the shock absorber and the link are mounted together on an axle body that defines the pivot axis. The axle body can optionally be made in several pieces, in any case it goes through all three components and transmits the forces acting transversely to the pivot axis between the wheel carrier, link and shock absorber. The individual bearing points of the wheel carrier, link and shock absorber are arranged along the axle body, with different arrangements or sequences being conceivable, some of which will be explained below. The construction with a single axle body allows the number of parts used to be reduced and assembly to be simplified, since both the link and the shock absorber are secured to a certain extent by a component (possibly in several pieces) in relation to the wheel carrier.

The axle body is preferably designed in one piece as an axle pin. This further contributes to simplification of structure and cost reduction. For reasons of stability, the axle pin can typically be made of steel, but it can also be made of aluminum or fiber-reinforced plastic. As part of During assembly, the axle pin, which may be inexpensive to produce, can be guided in one operation through recesses provided for this purpose in the wheel carrier, the link and the shock absorber. As will be explained later, at least one of the elements mentioned can be mounted indirectly on the axle pin.

There are different possibilities with regard to the storage of the individual components on the axle body or axle pin. According to the invention, one of the wheel carrier, shock absorber and control arm components is mounted on the axle body via a single bearing, while the other two are each mounted on the axle body via a double bearing formed on a fork section, axially on both sides of the single bearing. In this context, a section of the respective component is referred to as a fork section, which fork-like branches into two sections. A double bearing is formed on this fork section, which has two individual bearings that are axially spaced apart from one another. Each of the individual bearings is of course formed on one of the sections, in particular at the end. The single bearing as well as the double bearing each have bearing eyes, for example within a bearing sleeve. The axle body is passed through these bearing eyes. In this embodiment, the single bearing is to a certain extent flanked by the double bearings. The design with double bearings enables better guidance of the respective components and better absorption of any forces occurring transversely to the axial direction. In addition, such forces act on both sides of the individual bearing, one could say in a "symmetrical" manner, and therefore do not necessarily lead to a torque that would unnecessarily load the axle beam or the individual bearing.

According to a preferred embodiment, the wheel carrier has a wheel carrier bearing as a single bearing, the shock absorber has two damper bearings formed on a first fork section as a first double bearing, and the link has two link bearings formed on a second fork section as a second double bearing. i.e. The wheel carrier bearing is arranged on the inside along the pivot axis or along the axle body, which is flanked on the outside, ie axially on both sides, by two damper bearings and two link bearings. In this embodiment, too, there are different possibilities with regard to the arrangement of the link bearings and the damper bearings relative to one another. For example, both link bearings could be arranged in front of or behind a damper bearing in the axial direction. The link bearings are preferably arranged axially on the outside of the damper bearings. That is, the damper bearings are to a certain extent flanked by the link bearings and are arranged between them. As a result, when a force is applied transversely to the axial direction by the link or the shock absorber, the center of the force is always approximately in the same area, typically within the wheel carrier bearing.

According to a structurally simple and inexpensive, but at the same time effective embodiment, the axle pin is formed by a screw that interacts with a nut. That is, the axis pin corresponds to the screw shank, which is passed through the above-mentioned bearing, whereby the screw shank can rest directly or indirectly on the outermost bearing and on the opposite side the nut, which is screwed to the screw, also directly or indirectly can rest against the outermost bearing. It is understood that a washer can be used to support the screw head and/or nut.

The wheel carrier is preferably mounted on the axle pin via a rubber-metal bush. A corresponding rubber-metal bush has a metal inner sleeve, which is surrounded concentrically by a rubber-elastic element (or simply: rubber element) and normally by an outer sleeve, which is also made of metal. The axle pin is guided through the inner sleeve and the outer sleeve (or the rubber-elastic element) is accommodated in a bearing eye of the wheel carrier bearing. Due to the elasticity of the rubber-elastic element, the wheel carrier and the axle pin can be moved relative to one another to a limited extent. Axial, radial, tangential and cardanic movements are conceivable. Thus, such a bearing can act similarly to a ball joint to a limited extent. Apart from the fact that different degrees of freedom are created by the elasticity, the rubber-elastic element also serves to prevent the transmission of vibrations, which are undesirable from the point of view of NVH.

Furthermore, it is preferred that a spacer element is arranged axially between at least two adjacent bearings. Such a spacer element can be, for example, a washer, which facilitates or enables independent pivoting movement of the components associated with the adjacent bearings.

• 1 eine rückwärtige Ansicht einer ersten erfindungsgemäßen Radaufhängung;
• 2 eine Schnittdarstellung gemäß der Linie II-II in 1; und
• 3 eine Schnittdarstellung gemäß der Linie III-III in 1.

Further advantageous details and effects of the invention are explained in more detail below using an exemplary embodiment illustrated in the figures. Show it:

• 1 a rear view of a first wheel suspension according to the invention;
• 2 a sectional view according to the line II-II in 1 ; and
• 3 a sectional view according to the line III-III in 1 .

In the different figures, the same parts are always provided with the same reference numbers, which is why they are usually only described once.

1 until 3 show a schematic representation of a wheel suspension 1 according to the invention of a motor vehicle, for example a passenger car 1 a rear view, wherein the plane of the drawing corresponds to the YZ plane of the vehicle. The wheel suspension 1 is described below with reference to the illustration in 1 as well as the sectional views in 2 and 3 described.

The wheel suspension 1 has a wheel carrier 2, which is used for the rotatable mounting of a vehicle wheel, not shown. On the vehicle side, it is connected to a chassis (also not shown) of the motor vehicle via a lower transverse link 8 (and via other links not shown here). The wishbone 8 can be pivoted relative to the wheel carrier 2 about a pivot axis S, which runs parallel to the X-axis. The wheel carrier 2 is spring-loaded relative to the chassis by a spring (not shown). On the one hand, the spring can be supported either on the wheel carrier 2 itself or on a link, for example the wishbone 8 shown, and on the other hand on the chassis. There is also a pivotable connection between the wishbone 8 and the chassis, which ensures overall mobility of the wheel carrier 2 as part of the unsprung mass in relation to the chassis as part of the sprung mass. Furthermore, the wheel suspension 1 has a shock absorber 5 with a piston rod 7 and a damper cylinder 6 . The shock absorber 5 serves to prevent unwanted vibration behavior of the wheel carrier 2 relative to the chassis. As in 1 can be seen, which can correspond, for example, to a state of normal loading, the shock absorber 5 does not run perpendicularly along the Z-axis but is inclined with respect to it. The angle of inclination must change during compression, which is why the shock absorber 5 can also be swiveled in relation to the wheel carrier 2, also about the swivel axis S.

This means that the wishbone 8 and the shock absorber 5 can be pivoted about the same pivot axis S relative to the wheel carrier 2 . As from the comparison of 2 and 3 As becomes clear, both partly occupy the same position along the X-axis, but this does not lead to any problems, since they are inclined differently within the YZ-plane and therefore do not collide with each other. Mechanically, the joint pivotability about the pivot axis S is realized in that both the wheel carrier 2 and the shock absorber 5 and the wishbone 8 are mounted on a screw shank of a screw 14 acting as an axle body 14.1 or axle pin. The wheel carrier 2 is mounted approximately in the middle of the screw shank via a wheel carrier bearing 2.1, with a rubber-metal bushing 9 having a metal outer sleeve 10 being pressed into a bearing eye of the wheel carrier 2. A metallic inner sleeve 12 is arranged concentrically within the outer sleeve 10, as well as an interposed rubber element 11. The rubber-metal bushing 9 on the one hand provides a certain degree of relative movement between the wheel carrier 2 and the screw 14, and on the other hand vibrations occurring on the part of the wheel can be damped are and are thus at best transmitted to the chassis to a small extent. While the wheel carrier bearing 2.1 is designed as a single bearing, the shock absorber 5 is mounted on the screw shaft via a first double bearing. The first double bearing is formed on a first fork section 7.1 of the piston rod 7 and has a first damper bearing 7.2 and a second damper bearing 7.3. Said damper bearings 7.2, 7.3 are arranged approximately symmetrically axially on both sides of the wheel carrier bearing 2.1. As a result, in the case of forces from the shock absorber 5 which act transversely to the pivot axis S, the center of the force lies within the wheel carrier bearing 2.1. In order to improve the pivotability of the shock absorber 5 relative to the wheel carrier 2, washers 13 are interposed between the wheel carrier bearing 2.1 and each of the damper bearings 7.2, 7.3.

The wishbone 8 is mounted on the screw shank via a second double bearing, which is formed on a second fork section 8.1 of the wishbone 8. It has a first link bearing 8.2 and a second link bearing 8.3. The link bearings 8.2, 8.3 are also arranged approximately symmetrically axially on both sides of the wheel carrier bearing 2.1, specifically on the outside of the damper bearings 7.2, 7.3. As a result, when forces are exerted on the part of the wishbone 8, which act transversely to the pivot axis S, the center of the force lies within the wheel carrier bearing 2.1. Washers 13 are also interposed between the first damper bearing 7.2 and the first link bearing 8.2 and between the second damper bearing 7.3 and the second link bearing 8.3.

In order to secure the position of the screw 14, it is screwed to a nut 15 at one end of the screw shank, which is opposite a screw head 14.2.

The wheel suspension 1 shown requires only a comparatively small installation space, since the connection of the shock absorber 5 as well as the wishbone 8 takes place via one and the same wheel carrier bearing 2.1. In addition, the overall weight is generally lower than designs in which the shock absorbers and control arms pivot about different pivot axes. Since both the shock absorber 5 and the wishbone 8 are secured to the wheel carrier 2 with one and the same screw 14, the wheel suspension 1 can be implemented inexpensively and assembled easily.

Reference List

1

suspension

2

wheel carrier

2.1

wheel carrier bearing

5

shock absorber

6

damper cylinder

7

piston rod

7.1, 8.1

fork section

7.2, 7.3

Damper Bearing

8th

wishbone

8.2, 8.3

handlebar bearing

9

rubber-metal bushing

10

outer sleeve

11

rubber element

12

inner sleeve

13

washer

14

screw

14.1

axle body

14.2

screw head

15

Mother

S

pivot axis

X

X axis

Y

Y axis

Z

Z axis

Claims (8)

Wheel suspension (1) for a motor vehicle, with a wheel carrier (2) to which a shock absorber (5) and a link (8) are pivotably connected, the shock absorber (5) and the link (8) being independently of one another about a common, axially running pivot axis (S) relative to the wheel carrier (2), characterized in that the wheel carrier (2), the shock absorber (5) and the link (8) are mounted together on an axle body (14.1) defining the pivot axis (S). one of the components wheel carrier (2), shock absorber (5) and link (8) is mounted on the axle body (14.1) via a single bearing (2.1), while the other two each have a bearing formed on a fork section (7.1, 8.1). Double bearings (7.2, 7.3, 8.2, 8.3) are mounted axially on both sides of the single bearing (2.1) on the axle body (14.1). suspension after claim 1 , characterized in that the pivot axis (S) runs parallel to the X-axis of the motor vehicle, the link (8) being designed as a wishbone. suspension after claim 1 or 2 , characterized in that the axle body (14.1) is designed in one piece as an axle pin. Wheel suspension according to one of the preceding claims, characterized in that the wheel carrier (2) has a wheel carrier bearing (2.1) as a single bearing, the shock absorber (5) has two damper bearings (7.2, 7.3) formed on a first fork section (7.1) as has a first double bearing and the link (8) has two link bearings (8.2, 8.3) formed on a second fork section (8.1) as a second double bearing. suspension after claim 4 , characterized in that the link bearings (8.2, 8.3) are arranged axially on the outside of the damper bearings (7.1, 7.2). Wheel suspension according to one of the preceding claims, characterized by an axle pin which is formed by a screw (14) which interacts with a nut (15). Wheel suspension according to one of the preceding claims, characterized in that the wheel carrier (2) is mounted on an axle pin via a rubber-metal bush (9). Wheel suspension according to one of the preceding claims, characterized in that a spacer element (13) is arranged axially between at least two adjacent bearings (2.1, 7.2, 7.3, 8.2, 8.3).

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