Wishbone for a wheel suspension of a steerable wheel of a motor vehicle

Abstract

Wishbone (1) for a wheel suspension of a steerable wheel of a motor vehicle, with a control arm part (2) extending along the Y-axis (Y) of the motor vehicle, which - a chassis-side connection point (3) for a chassis, as well as - has a wheel-side connection point (4) for a wheel carrier, wherein a separately manufactured connecting part (5) for the pivotable connection of a spring strut (20) to the wishbone (1) is rigidly connected to the control arm part (2), characterized in that the connecting part (5) is arranged on the upper side of the control arm part (2) and comprises a flange section (5.1) which bears against the control arm part (2) and has bores (5.2) through which screws (12) or rivets are guided for connection to the control arm part (2).

Description

The invention relates to a suspension arm for a steerable wheel of a motor vehicle according to the preamble of claim 1.The generic DE 197 48 117 A1 discloses a ball stud of a ball joint for motor vehicles, having a joint ball and a stud connected to the joint ball, wherein a substantial part of the stud is designed to be non-round in order to prevent the ball stud from rotating.DE 10 2013 012 647 A1 discloses an elastomer bearing for a steering arm of a vehicle, for elastically coupling the steering arm to a component. The elastomer bearing has a bearing body made of an elastic plastic, which encloses a coupling element in a circumferential direction, by means of which coupling element the elastomer bearing can be connected to a component, and a bearing jacket (made of metal, which encloses the bearing body in the circumferential direction and by means of which bearing jacket the elastomer bearing can be connected to the link.DE 1 080 866 A discloses a wheel suspension for vehicles, in particular motor vehicles, with wheels which are guided by upper suspension arms and lower suspension arms and are sprung by means of helical springs arranged between the lower suspension arms and the vehicle frame, the upper and the lower seats of the springs being at the same distance from the pivotable connections of the lower suspension arms to the frame. The only embodiment shows a telescopic shock absorber, the lower end of which forms a ring which is seated on a bolt of the suspension arm. The telescopic shock absorber is surrounded by a spring which rests directly on a press-fit of the link.In modern motor vehicles, all wheels are connected to the vehicle body, i.e. to the body or chassis of the vehicle, via a wheel suspension. Such a suspension achieves two tasks in particular: on the one hand, the guidance of the wheel carrier or of the wheel and, on the other hand, the suspension thereof. The respective wheel and a wheel carrier receiving the same are here part of the unsprung mass, which follows more or less the height profile of the respective travel surface, while the body and chassis form parts of the sprung mass, which is intended to 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 sprung and unsprung masses into heat and thus prevent undesired vibration behavior.The guidance of the wheel carrier is ensured primarily by links (for example transverse links or longitudinal links) which run more or less horizontally and by means of which the wheel carrier is connected to the chassis. In addition to wheel suspensions in which the spring is connected at least indirectly to the wheel carrier, designs are also known in which the spring acts on a link. Often, the spring is part of a spring-damper unit, for example, a coil spring concentrically surrounding a shock absorber.The suspension arm or arms connect the wheel carrier to vehicle-side components of the chassis, for example an auxiliary frame. Normally, such a suspension arm has one or two chassis-side connection points and a wheel-side connection point. The chassis-side connection points, via which an articulated connection is provided, for example, by metal-rubber composite bearings, are usually aligned with the X-axis (i.e., the longitudinal axis) of the vehicle in the installed state, so that a pivoting movement of the wheel-side connection point in the Y-Z plane is made possible. The main function of the suspension arm is to absorb horizontal forces (i.e. lying in the X-Y plane) together with other suspension components.In addition to forged transverse guide rods, which are usually made of light metal or steel, guide rods are also known in the prior art which are manufactured in one shell or two shells as sheet metal formed parts. In order to provide such a link with the necessary strength, the sheet metal is formed by a suitable forming process (for example. Drawing) is provided with a profile which typically gives it a dish-like structure. Furthermore, transverse links are also known which consist at least partially of fiber-reinforced plastic.CN 203995532 U shows a forged suspension arm with two end-side through openings between which a connecting section extends. The contour of the connecting portion has a series of curves and troughs extend along the top and bottom sides of the connecting portion.A typical design of the wheel suspension for a controllable axle (i.e. normally the front axle) is the so-called double-suspension suspension of the transverse suspension. In this case, the wheel carrier is guided by two suspension arms arranged one above the other. The wheel-side connection points of the two suspension arms also define the pivot axis about which the wheel carrier is rotated during steering movements. In principle, the two links can be arranged parallel and of the same length, as a result of which, however, the track width changes during compression and the wheel follows the lateral inclination of the chassis. In order to avoid this, the upper link is normally made shorter, so that a negative camber results during compression, which counteracts the roll movement, for example, in a curve. Due to the configuration with a short and a long suspension arm, this configuration is also referred to as an SLA wheel suspension (short and long arm).In contrast, in the so-called McPherson wheel suspension, only one suspension arm is used which defines the lower part of the pivot axis for the steering movement, while the upper part thereof is provided by a suspension strut which acts directly on the wheel carrier. It rotates with it during the steering process and is therefore normally mounted on the body via a rolling bearing.Often, both SLA and McPherson front wheel suspensions with or without a lower link plane resolved, i.e. with two individual 2-point links (a usually laterally oriented link primarily for absorbing transverse forces and a link diagonally oriented in plan view primarily for absorbing longitudinal forces) or else with a triangular link, are to be installed within a vehicle series or platform. In this case, the shape and the stability of the suspension arm must be individually adapted to the respective vehicle for both types of wheel suspension. In particular, the respective connection points must also be individually constructed depending on the vehicle type. In addition, depending on the type of suspension, the suspension arm either has to be designed for connection to a suspension strut or not. Thus, a specially adapted suspension arm must be developed and produced in each case here, which is associated with time and cost expenditure.In view of the state of the art presented, simpler planning and production of suspension arms, in particular with regard to different types of suspension, still offers room for improvements.The invention is based on the object of simplifying the provision of suspension arms for different types of suspension.According to the invention, the object is achieved by a suspension arm having the features of claim 1.A suspension arm for a steerable wheel of a motor vehicle is disclosed, having a arm part extending along the Y axis of the motor vehicle, which arm part is connected to the steering wheel of a steerable wheel of a motor vehicle.a chassis-side connection point for a chassis, anda wheel-side connection point for a wheel carrierwherein a separately manufactured connecting part is rigidly connected to the link part for the pivotable connection of a strut to the suspension arm. According to the invention, the connecting part is arranged on the upper side of the link part and comprises a flange section which abuts on the link part and has bores through which screws or rivets serving for connection to the link part are guided.The dependent claims relate to advantageous embodiments of the invention.It should be noted that the features and measures individually listed in the following description can be combined with one another in any technically meaningful manner and reveal further configurations of the invention. The description additionally characterizes and specifies the invention, in particular in conjunction with the figures.The invention provides a suspension arm for a steerable wheel of a motor vehicle. In particular, cars or trucks are considered as motor vehicles. It is normally a front wheel suspension.As already mentioned above, the transverse link has a link part which extends along the Y axis of the motor vehicle and has a chassis-side connection point for a chassis and a wheel-side connection point for a wheel carrier. The connection points mentioned are points or regions at which a connection to the wheel carrier or chassis can be produced directly or indirectly. Such a connection point can be provided, for example, by a bearing bush, a bearing journal, a ball joint receptacle or the like. It is also conceivable, as is known in the prior art in a similar manner, for example to connect a ball joint receptacle as a separately manufactured component to the actual link part by riveting, screwing or the like. In such a case, the region of the link part which is provided for fastening the ball joint receptacle and for this purpose has, for example, bores, can also be regarded as a connection point. The link part represents a part of the suspension arm which, in the installed state, extends from the chassis (for example an auxiliary frame) to the wheel carrier. In this installed state, the steering arm part extends along the Y axis (transverse axis) of the vehicle, but does not have to extend parallel thereto.The connection point on the chassis side serves for the pivotable connection to the chassis of the vehicle and defines a pivot axis which normally runs parallel to the X axis (longitudinal axis) of the vehicle. The link part can in particular also comprise two chassis-side connection points which are spaced apart from one another along the X axis. In this case, the link part can be L-shaped, A-shaped or V-shaped or curved. The wheel-side connection point serves for the pivotable connection to the wheel carrier. In the case of a steerable wheel (front wheel), the wheel carrier must be pivotable, in addition to being pivotable about the X axis, about a further axis which approximately coincides with the Z axis (vertical axis) of the vehicle, which can be realized either by an additionally interposed component or, for example, by a ball joint.The link part itself can be of shell construction (single-shell or multi-shell) or solid design. It can be forged from steel or light metal, formed from steel sheet or manufactured from fiber-reinforced plastic.As stated above, a separately manufactured connecting part for pivotally connecting a strut to the suspension arm is rigidly connected to the arm part. The connecting part is rigidly connected to the link part so that it moves with the link part and behaves like a part thereof. It is designed in such a way that a strut can be pivotably connected to the suspension arm there (optionally with the interposition of a bearing). Usually, the connecting part defines a pivot axis which likewise runs parallel to the X axis. The connecting part thus enables a suspension strut to crash onto the suspension arm, which is customary, for example, in the case of a double-arm wheel suspension, but not, for example, in the case of a classic McPherson wheel suspension, where the suspension strut is supported directly on the wheel carrier. It can be provided here that the spring strut has a fork which engages around the connecting part on both sides, or else that the connecting part itself engages around an end of the spring strut in the manner of a jaw. The connecting part can in principle be made of the same materials as the link part, but different materials could also be combined with one another, so that, for example, the link part is a forged light metal part, while the connecting part is at least partially made of fiber-reinforced plastic.The particular feature of the suspension arm according to the invention is that the connecting part represents a separately manufactured component which is subsequently connected to the suspension arm part. If it is not provided that a suspension strut crashes onto the suspension arm and thus the connecting part is not necessary, this can be omitted, which still results in a fully functional suspension arm. The geometry of the transverse link is substantially determined by the link part and is thus largely independent of the presence of the connecting part. Of course, the configuration of the above-mentioned is also applicable. Connection points regardless of whether a connecting part is present or not. The suspension arm is constructed so to speak in a modular manner, wherein the connecting part represents a module which is used if required. It is thus possible to flexibly design a suspension arm, which is adapted to a specific vehicle model with regard to geometry and connection to chassis or wheel carrier, into different suspensions (for example. For example, to integrate the double-control arm suspension or MacPherson suspension). Therefore, depending on requirements, it is not necessary to develop or produce a completely new suspension arm, but rather only the connecting part is inserted or not.Normally, the suspension arm comprises a single connecting part, but it would also be conceivable for a plurality of connecting parts to be present or for the connecting part to be formed in a number of parts in itself.In order to ensure the most stable possible structure of the suspension arm and simple production, it is advantageous if the arm part consists of few parts, as is also the case with conventional suspension arms which are forged, for example, from a single piece or consist of one or two sheet metal shells. In this aspect, it is preferable that the link part comprises a portion which is manufactured in one piece and extends from the chassis-side connection point to the wheel-side connection point and to which the connecting part is connected. The mentioned section transmits forces between the connection points and between these and the connecting part. The stability required for this can best be ensured by a one-piece production. The mentioned section can be formed as a sheet metal formed part, as a forged metal part or as a part formed from fiber-reinforced plastic.Since in all common suspension concepts the suspension strut crashes from above onto the suspension arm, the connecting part is arranged, as mentioned above, on the top side of the arm part. That is, in the installation position, the connecting part is located on the upper side of the link part (i.e., the side located at the top in the direction of the Z axis). Alternatively, however, it would also be conceivable, for example, for the connecting part to be arranged laterally (i.e. in the direction of the X axis) with respect to the link part.Since the connecting part constitutes a kind of additional module which is intended to have little influence on the shape, weight and stability of the suspension arm, it is normally formed to be significantly smaller than the arm part. It is preferred here that an extension of the connecting part along the Y axis is less than 50% of an extension of the link part. That is, if the extension of the connecting part is measured along the Y-axis, then this is less than 50% of the extension of the link part in the mentioned embodiment. Further, the extent may be less than 40%.In principle, various possibilities are conceivable for how the connection between the connecting part and the link part can be produced. This naturally also depends on the material or materials from which the mentioned parts are manufactured. If both parts are manufactured from fiber-reinforced plastic, for example, the connection could be produced by ultrasonic welding or adhesive bonding. Conventional welding could be done for metal parts. Other material connections are also conceivable. According to a preferred embodiment, the connecting part is connected to the link part in a form-fit and / or force-fit manner. In particular, the connection can be designed to be releasable in this case, which has the advantage that the type of use of the suspension arm is not fixed for all times, but that, for example in the case of a suspension arm which is to be used in a McPherson wheel suspension system, an already mounted connecting part can be disassembled again. The form-fit or force-fit connection can be produced in a known manner by means of interposed connecting components such as screws, nuts or rivets. For example, the connecting part can have non-threaded bores through which screws are passed, which in turn engage in threaded bores of the link part.With regard to a releasable connection as well, it is preferred that the connecting part is screwed to the link part. This includes in principle the possibility that the connecting part and the link part have complementary threads to one another, although it is preferred that the screw connection is produced by intermediate screws.There are a multiplicity of ways in which the connection between the connecting part and the link part can be optimized with regard to its stability and the force transmission. For example, the two parts could have mutually complementary surface structures in a region where they are joined together, which surface structures engage one another to a certain extent. As already mentioned above, the connecting part comprises a flange section which abuts on the link part. This provides for an enlarged contact surface on the one hand, and the flange section has bores through which screws or rivets serving for connection to the link part are guided, as already stated above.As is also known in the prior art in the case of suspension arms, the connection point on the chassis side can have a rubber-metal bushing. In the installed state, this bushing is engaged by an axle which is mounted on the chassis. Typically, such a rubber-metal bushing consists of an inner metal cylinder and an outer metal cylinder, between which a cylindrical rubber element is arranged. As is known, such a rubber-metal bushing serves to minimize the transmission of vibrations and to absorb any stresses that may occur.Accordingly, it may be expedient for the connecting part to have a rubber-metal bushing. In the installed state, this is traversed by an axis which represents the pivot axis of the suspension strut with respect to the suspension arm.As already explained, the suspension arm according to the invention is part of a suspension of a steerable wheel. Since for this purpose the wheel carrier must not only be pivotable about the X axis with respect to the suspension arm, but also must additionally enable a pivoting about the Z axis according to the steering movement with respect to the vehicle, an articulated connection can be provided which enables a pivoting about a plurality of axes, i.e. normally a ball joint. For this purpose, the wheel-side connection point can have a ball joint receptacle. In the assembled state, a ball stud can be accommodated in the ball joint receptacle, wherein the connection is protected in a known manner by a bellows.Further advantageous details and effects of the invention are explained in more detail below with reference to an exemplary embodiment shown in the figures. The following are shown: FIG. 1 shows a schematic front view of a suspension arm according to the invention and of a suspension strut; and FIG. 2 shows a schematic sectional illustration of the suspension arm from FIG. 1.FIGS. 1 and 2 each show a schematic representation in front view of a suspension arm 1 according to the invention for a motor vehicle, for example a car. Here, FIG. 2 shows a sectional view. The plane of the drawing corresponds in each case to the Y-Z plane of the vehicle. The suspension arm 1 has as its main component a suspension arm part 2 which in the present case is made of light metal, for example. As can be seen in the drawing, this link part 2 and in particular a section 2.1 of the same which is formed in one piece extends from a connection point 3 on the chassis side to a connection point 4 on the wheel side. The connection point 3 on the chassis side, which can also be an auxiliary frame, has a rubber-metal bushing 6, which is formed in a known manner by an inner metal cylinder 6.1, an outer metal cylinder 6.3 and an interposed rubber core 6.2. By its shape, the rubber-metal bush 6 defines a first pivot axis A about which the suspension arm 1 is pivotable with respect to a chassis and / or auxiliary frame (not shown). The pivot axis A is parallel to the X axis of the vehicle.The overall structure of the suspension arm 1 can be designed, for example. L-shaped, wherein a further connection point can be located behind the chassis-side connection point 3 in the direction of the X axis.At the end of the link part 2 opposite in the direction of the Y-axis, the wheel-side connection point 4 is formed with a ball joint receptacle 2.2, in which a ball stud 10 is rotatably mounted in a known manner. The latter is surrounded by a bellows 11. In the assembled state, a wheel carrier, not shown here, is mounted rotatably and pivotably via the ball stud 10.With the components discussed so far, the suspension arm 1 could also be used, for example, within a McPherson wheel suspension system, in which a suspension strut 20 acts directly on the wheel carrier and would rotate together with the latter during a steering operation.In the present case, however, the suspension arm 1 is part of a double-arm wheel suspension system in which the suspension strut 20 acts directly on the suspension arm 1. For this purpose, a connecting part 5 is rigidly connected to the link part 2. The connection is realized by screws 12 which are guided through bores 5.2 in a flange section 5.1 of the connecting part 5 and are screwed into threaded bores 2.3 of the link part 2. The connecting part 5 is also designed as a light metal element in the present case.Inside the connecting part 5 is arranged a further rubber-metal bushing 7 which, similar to the rubber-metal bushing 6, comprises two metal cylinders 7.1, 7.3 and a rubber core 7.2 lying therebetween. An axle (not shown here) of a fork 21 of the strut 20 is guided through the inner metal cylinder 7.1. This provides for the suspension strut 20 to be pivotable relative to the suspension arm 1 about a second pivot axis B, which likewise runs parallel to the X axis.If the suspension arm 2 is used in an alternative wheel suspension in which no suspension strut 20 crashes onto it, the connecting part 5 can be omitted. Since a releasable connection is provided by the screws 12, a corresponding decision can also be made after the connecting part 5 has already been mounted.List of reference numbers:1 Suspension arm 2 Suspension arm part 2.1 Section 2.2 Ball joint receptacle 2.3 Threaded bore 3 Chassis-side connection point 4 Wheel-side connection point 5 Connecting part 5.1 Flange section 5.2 Bore 6, 7 Rubber-metal bushing 6.1, 6.3, 7.1, 7.3 Metal cylinder 6.2, 7.2 Rubber core 10 Ball stud 11 Bellows 12 Screw 20 Strut 21 Fork A, B Pivot axis X X-axis Y Y-axis Z Z-axis

Claims

A suspension arm (1) for a steerable wheel of a motor vehicle, having a arm part (2) extending along the Y axis (Y) of the motor vehicle, which arm part has - a chassis-side connection point (3) for a chassis, and - a wheel-side connection point (4) for a wheel carrier, wherein a separately manufactured connecting part (5) is rigidly connected to the arm part (2) for the pivotable connection of a suspension strut (20) to the suspension arm (1), characterized in that the connecting part (5) is arranged on the top of the arm part (2) and comprises a flange portion (5.1) which bears against the arm part (2) and has bores (5.2) through which screws (12) or rivets serving for connection to the arm part (2) are guided.Transverse link according to Claim 1, characterized in that the link part (2) comprises a section (2.1) which extends from the connection point (3) on the chassis side to the connection point (4) on the wheel side and is produced in one piece and to which the connecting part (5) is connected.Transverse link according to one of the preceding claims, characterized in that, along the Y axis (Y), an extent of the connecting part (5) is less than 50% of an extent of the link part (2).Transverse link according to one of the preceding claims, characterized in that the connecting part (5) is screwed to the link part (2), the screws (12) which are guided through the bores (5.2) of the flange section (5.1) being screwed into threaded bores (2.3) of the link part (2).Suspension arm according to one of the preceding claims, characterized in that the connection point (3) on the chassis side has a rubber-metal bushing (6).Suspension arm according to one of the preceding claims, characterized in that the connecting part (5) has a rubber-metal bush (7).Suspension arm according to one of the preceding claims, characterized in that the wheel-side connection point (4) has a ball joint receptacle (2.2).

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