Individual wheel suspension of a double wishbone type

The invention relates to an independent suspension, wherein the wheel guide is based on the concept of the double-wishbone suspension. With independent suspension systems of this type, the wheel carrying member via an upper and a lower arm to the vehicle frame is connected. The upper and lower control arms on the one hand pivotally attached to the vehicle frame and on the other hand articulated to the wheel carrier.

different constructions for independent suspension of steerable wheels of a vehicle axle are known from the prior art. From the<patcit id="pcit0001" dnum="EP1557339A1"><text>EP 1557339 A1</text></patcit> discloses an independent suspension for the steerable wheels of a front axle of a commercial vehicle. This includes a subframe on, are mounted on the parts of the suspension and steering, as well as a lower and upper wishbone as wishbones, the lower wishbone and a ball joint to the connecting part of a wheel carrier and the upper wishbone with a widely projecting part of the supporting pivot is also connected to a ball joint. Both wishbones are connected via elastic bearing with the subframe, and between the upper and lower arm is arranged a spring-damper system. The spring-damper system is designed as an air spring strut exhibiting.

A disadvantage of the from the <patcit id="pcit0002" dnum="EP1557339A1"><text>EP 1557339 A1</text></patcit> known independent suspension is that the lower wishbones at the wheel of their side facing away from very far extend towards the vehicle center line. For this reason, the existing between the lower wishbones space is limited.

From the <patcit id="pcit0003" dnum="DE10011417A1"><text>DE 100 11 417 A1</text></patcit> is an individual wheel suspension for the steerable vehicle axle of a vehicle known, which is constructed according to the principle of the double pendulum axis. This known independent suspension has wheel leading-trailing arm on which support the wheels on wheel carriers articulated and their transverse and longitudinal control arms are below a plane passing through the wheel centers horizontal plane, and the transverse control arms are each longer than half the track width. Due to the long wishbone arms of the space between the independent suspension one axle is severely limited even in this known independent suspension.

From the <patcit id="pcit0004" dnum="DE20022516U1"><text>DE 200 22 516 U1</text></patcit> is an independent suspension known which should preferably be suitable for medium and heavy trucks. In this suspension, the vehicle side member designated by the numeral 1 are the main support members of the vehicle frame construction. Each wheel suspension assigned to a vehicle longitudinal beam, so that under the vehicle body two vehicle longitudinal beams are arranged, which are lattice via several cross members or box-like connected to one another and form the vehicle frame. This classic and well-known construction method of a vehicle frame is also referred to as a lead frame, since the cross member like the rungs and the longitudinal members as the uprights of a ladder appearance. In addition to the vehicle frame is in accordance with<patcit id="pcit0005" dnum="DE20022516U1"><text>DE 200 22 516 U1</text></patcit> an auxiliary frame 2 is provided, which is secured to the wheel suspension. This subframe assumes no independent support function for the occurring in the driving mode and / or in the event of a crash high forces, but it is according to claim 1 on the vehicle frame, that is fixed to the vehicle longitudinal beams. The high, resulting in dynamic driving and in crash forces are absorbed by the longitudinal beams of the vehicle frame to which the subframe via the gusset plates 14 and connection angle is tied 15th The subframe itself serves only to secure the spring retainer, which wishbone, trailing arms, shock absorbers and wheel, so to attach the suspension elements. The core idea of<patcit id="pcit0006" dnum="DE20022516U1"><text>DE 200 22 516 U1</text></patcit> is to establish independent of the vehicle frame and wheel suspension sub-frame as an independent module, and then to mount this module on the vehicle frame.

A disadvantage of the from the <patcit id="pcit0007" dnum="DE20022516U1"><text>DE 200 22 516 U1</text></patcit> known construction is that all forces that occur in dynamic operation or in the event of a crash, can be taken only by the longitudinal members of the vehicle frame. The longitudinal members must therefore be interpreted accordingly strong. Also, the rigidity of these vehicle frame structure is limited, because the load paths, ie, the force flow paths through which the forces acting on the vehicle frame forces can be derived, extend through the longitudinal support of the vehicle frame and thus lie in a single horizontal plane.

The invention has for its object to provide an independent suspension for a vehicle axle with steerable wheels, at one hand, a large installation space as possible between two independent suspension one axle is available, and the other hand, leads to an increase in the stiffness of the overall structure of the vehicle frame.

This object is achieved by an independent suspension having the features of claim 1. Advantageous developments are specified in the dependent claims.

In the inventive solution is achieved through the clever arrangement of the wishbone that the length of the wishbone can be significantly reduced. The wishbones are directly connected to the longitudinal beams of the vehicle frame, so that the entire space between the side members of the vehicle frame is not influenced and limited by the wishbone.

According to the direct connection of the wishbone is on the longitudinal beams of the vehicle frame enables the fact that a particular frame structure is determined for the vehicle frame. This particular frame structure provides that every independent wheel suspension is associated with a frame structure consisting of a first and a second longitudinal member. The upper arm of the independent wheel suspension is connected to the first longitudinal beams, while the lower wishbone is connected to the second longitudinal member. Further, the second longitudinal member is substantially parallel to and spaced from the first longitudinal support arranged and the second longitudinal beam is fixedly connected via connecting elements with the first longitudinal member.

By this construction it is possible, seen in the direction transversely to the vehicle longitudinal axis, to use short-formed upper and especially lower wishbones. These short wishbone can be directly connected to the frame structure and do not project so that it does not restrict on the longitudinal member of the vehicle frame out toward the vehicle center, the space between the side rails.

A particularly large amount of space between the longitudinal members is reached when the two independent suspension assigned longitudinal carriers are arranged in a common, aligned parallel to the vehicle longitudinal direction plane.

Especially for heavy vehicles large forces on the wishbone act on the longitudinal members. Therefore, it is advantageous to provide a cross-sectional enlargement in the connection region of the wishbone to the first longitudinal member of a single wheel suspension. This increase in cross section results in an increase of the moment of resistance of the longitudinal support against bending and torsion. It can be advantageously realized by pointing in the direction the vehicle body shape of the first longitudinal member, the cross-sectional enlargement. If the first longitudinal member formed as C-profile, so it has an upper and connecting lower belts and these belts web. In this case may be formed larger for realizing the cross-sectional enlargement of the web of the first longitudinal member in the connection region of the wishbone. In this case, it is particularly economical to produce, the magnification of the web in the connection region of the wishbone metal forming in the preparation of the longitudinal support.

A particularly rigid construction is achieved when one connects the second longitudinal support the wheels of an axle respectively associated to each other by cross members to form a frame. Also, the first longitudinal member, which are the wheels of an axle associated with each can be connected to each other by one or more transverse tubes to increase the rigidity of the construction.

it when recording consoles are fastened to the first longitudinal member for receiving the connecting elements of the upper arm is particularly advantageous. These mounting brackets can be introduced between the straps and connected to the longitudinal support, for. Example, in the open cavity of a C-shaped profile. In the web of the longitudinal support recesses are then provided, through which the connecting elements of the upper arm can be guided, so that the connecting elements of the upper arm can be connected to the mounting brackets. In this way, the connection point of the upper wishbone is displaced towards the vehicle center, so that the upper arm can be made larger than would be the case if they would be connected directly via their connecting elements to the web of the longitudinal member. Simultaneously, the connecting elements of the upper arm do not protrude toward the vehicle center beyond the plane in which the first longitudinal member is.

In the solution according to the invention the connecting elements of the lower arm of the independent wheel suspension are connected to the second longitudinal member, which in parallel and spaced apart from the first longitudinal member is disposed. Preferably, the two independent suspension assigned longitudinal carriers are arranged in a common, aligned parallel to the vehicle longitudinal direction plane. In this case the connecting elements of the lower arm do not penetrate into the existing between the longitudinal beams a space, and therefore limit the lower wishbone not include the space between the longitudinal beams.

The invention is further illustrated with reference to an embodiment illustrative drawing. show in detail<dl id="dl0001"><dt>figure 1</dt><dd>an independent wheel suspension according to the invention in a perspective view in which the first and second longitudinal members are not shown for reasons of greater clarity of the drawing;</dd><dt>figure 2</dt><dd>a plan view of two inventive independent suspension one axle, which is also the first and second longitudinal members have been omitted for reasons of clarity;</dd><dt>figure 3</dt><dd>a perspective view of two inventive independent suspension including an axis of the first and second longitudinal members to which the independent wheel suspensions are fastened;</dd><dt>figure 4</dt><dd>an axle with two independent suspensions according to the invention and the associated first and second longitudinal members in a top view.</dd></dl>

In Figure 1, omitting the first and second longitudinal members to which the upper control arm 3 and the lower transverse link 2 are connected, shown a vehicle axle with two independent suspensions according to the invention. A single-wheel suspension according to the invention comprises a wheel 1 which is formed as a steering knuckle. The wheel carrier 1 carries an attachment member to which the vehicle wheel, not shown, can be attached.

With the wheel 1, an upper wishbone 3 and a lower arm 2 are articulated on ball joints. On the upper arm 3, a spring 11 is arranged. When installed, the spring 11 is effective between the vehicle body not shown in Figure 1 and the upper wishbone. 3 With her the vehicle body facing away from the end of the spring 11 is supported on the upper arm. 3

On the lower wishbone 2, a vibration based on 12th The vibration damper 12 is connected with its lower transverse control arm 2 remote from the end on a fastening element to the vehicle frame not shown in FIG. 1 The connection of the shock absorber 12 with its lower suspension arm 2 remote from the end to a mounting bracket 45 which is connected to the first longitudinal member 34 is illustrated in FIG. 3

The two independent suspensions are coupled to each other via a stabilizer 13 serving for roll stabilization.

Furthermore, the steering gear 15 is shown in FIG. 1 The output of the steering gear 15 represents an output shaft transverse to the direction of travel, which is firmly connected to the pitman arm 10th This pitman arm 10 acts via a ball joint 31 to the handlebar 9. The length of the pitman arm 10 will vary depending on vehicle model, so that there is always an optimal relationship between force and displacement can be set in the steering linkage. The steering linkage comprises the components pitman arm 10, handlebar 9 and track rod elements 4, 5, 6, 7, 8. The wheel guide is based on the concept of a double-wishbone suspension. In the illustrated embodiment accepts an air spring 11, the function of the body spring, which is positioned at the upper wishbone third Alternatively conceivable the use of a steel coil spring instead of the air spring 11. The lower arm 2 and the upper arm 3 is connected by ball joints to the steering knuckle. 1 The steering knuckle 1 refers to both the wheel bearing and the brake caliper. The tie rod 4 is connected to the steering knuckle located at 1 steering arm by means of a ball joint 22nd

In the top view shown in Figure 2, which is supported on the upper arm 3 air springs 11 are clearly visible. It is shown that the steering rod 9 is coupled via a reversing lever 7 mechanically connected to the tie rods 5,. 6 The mechanical coupling via connection elements 25, 27. Similarly, a guide lever 8 is on the other side is provided, which is coupled via connection 26 members 24 mechanically connected to the tie rods 6 and 4. FIG. The guide lever 8 is supported on the guide lever bearing 28, and the lever 7 is mounted on the bellcrank 29th

In Figure 3, the independent suspension of the wheels of an axle together with the upper and lower suspension arm 2, 3-supporting first and second longitudinal members 34, 37 are shown. The first longitudinal member 34 are connected to each other via a cross pipe 44, whereby the rigidity of the frame structure is increased. At the first side member 34 a single suspension mounting brackets 34 are arranged which receive the connecting elements 17, 18 of the upper arm. 3 Thus, the connection elements 17, 18 can be connected to the mounting brackets 34, is in the web of the first longitudinal member 34 of each receiving element 17, 18 a recess is provided through which the receiving elements 17, 18 each engage through. In this way, the upper wishbone 3 can be configured with longer legs than would be the case if the wishbone would not be connected in recording consoles, but directly and immediately with the web of the first longitudinal member 34th

At the arranged in the direction of travel right independent suspension of the second longitudinal member 37 is clearly visible. He firmly with connection elements 38, 39, 40 connected to the first longitudinal member 34th The connection elements 38, 39, 40 may be configured as metal stampings in the form of open profiles or formed from sheet metal stampings hollow profiles. On the right seen arranged in the direction of travel independent suspension is well to recognize that the lower wishbones 2 is connected to the second side member 37, while the upper wishbone is 3 connected to the first longitudinal member 34th At the first side rail 34 also brackets 35 and 45 is fixed. The console 35 is configured as arc-shaped receiving element and serves for supporting the air spring 11 relative to the vehicle body. If particularly large forces are absorbed, so a reinforcement member 36 can be attached to the first longitudinal beams 34 in addition to the bracket 35 yet. This is illustrated in. Figure 3. The reinforcing element 36 serves the additional support of the air spring 11 relative to the vehicle body.

In seen prior to the second side member 37 driving a deformation element 46 is arranged. This deformation element 46 may be referred to as crash element and serves primarily the energy absorption in the event of a crash. The deformation element 46 carries an underride guard 47 which is intended to prevent accidents partner in a crash fall (Partner Protection) under the vehicle body.

The console 45 which is connected to the first longitudinal member 34, the support of the shock absorber 12 relative to the vehicle body is used. The vibration damper 12 is connected to the lower wishbone 2 and is supported against the vehicle body via the bracket 45 directly on the first side rail 34 from.

The parallel arrangement of the first longitudinal member 34 and second longitudinal member 37, a second load path in the frame structure of the vehicle is provided. The vehicle frame thus comprises two second longitudinal members 37, which are joined together in each case of two half shells. The connection to the respective first longitudinal beams 34 via front, middle and rear link members 38, 39, 40 and on the rear cross member 42. A further connecting element is formed by the front cross member 41 (see FIG. 4). This construction can be described as a double frame construction. The first side member 34 form a primary frame, while the second side members form a secondary frame. The secondary frame includes the recording of the recording elements of the lower arm 2, the stabilizer 13 and the bearings 28, 29 for the lever 7 and the guide lever 8 of the tie rods 4, 5,. 6

The interaction of the primary vehicle frame and the secondary frame leads to an increase of the stiffness rates in the overall structure. Further forms - as already mentioned - the front end of the secondary frame recording for the deformation elements 46, on which in turn the front underrun protection is 47 fixed. Compared with conventional commercial vehicle constructions, introduced via the front underrun protection 47 Impact loads are not forwarded immediately behind the attachment of the deformation elements 46 to the top (first) side members 34, but there is a force distribution instead. The force at impact is introduced via a plurality of connections (connecting elements 38, 39, 40) in the first longitudinal member. This results in a balanced loading of the first longitudinal member 34th

A particular advantage of the independent wheel suspension according to the invention is that it can be combined regardless of manufacturer with the leadframe generally known in commercial vehicles.

When independent suspension according to the invention of the spring 11 and the shock absorber 12 can be absorbed by these elements forces are introduced via two different load paths in the frame structure by separate arrangement. End stops can be both in the air spring 11 and the damper 12 place and can be individually adjusted so as to give an optimal distribution of impact forces.

4 shows the view according to Figure 3 in plan member depicted. Evident are the looking toward front cross member 41 and the rear cross member 42, which connect the second 37 longitudinal members together to form a frame. In connection with the illustration in Figure 3 can be clearly seen that 34, a maximum space is available between the first longitudinal beams. Here engine components or other components can be integrated.

In known axle concepts, which are based on the use of Achsschenkelträgern and / or spring legs, there is no possibility for the integration of a drive shaft for a front wheel drive. In contrast, the present concept of the independent suspension of the invention provides the necessary for the integration of a drive shaft clearance. This necessary clearance is achieved primarily by the positioning of the air spring 11 on the upper arm 3 and the side of the lower arm 2 mounted shock absorbers 12th