Handlebars (vehicle technology)

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Wishbones. The axes of the rubber bearings are aligned. The large-volume "comfort bearing" enables small rotations around the vertical axis in the "guide bearing" and is used for longitudinal suspension of the wheel.

In chassis technology, control arms or axle guides are elements of the wheel suspension of motor vehicles and rail vehicles. They connect the wheel carrier on the one hand to the vehicle body on the other hand through joints and guide the wheel carrier. In passenger cars, leaf springs have largely been replaced by the separation of wheel guidance and suspension .

Forces and moments on the wheel carrier are introduced into the vehicle body via the links or their joints. Kinematic requirements and behavior under load must therefore be taken into account equally when designing the wheel suspension geometry.

In the case of wheel suspensions, one differentiates between control arms based on their function (load-bearing or guiding) and their kinematic effect according to the number of articulation points. There are four basic types:

  • Handlebar with 2 pivot points
  • Wishbone with 3 ball joints (two ball joints at the base form a swivel joint)
  • Trapezoidal link with 4 ball joints.
  • Swivel arm : handlebar with a ball joint and a swivel joint. An example is the piston rod of a shock absorber .

Other distinguishing features are the direction in space z. B. wishbones , trailing arms , trailing arms or according to the type of predominant stress ( thrust strut , tension strut ). Manufacturer- specific designations such as camber struts are intended to indicate the importance of the link for the wheel position on multi-link axles. The length of the tie rod or the toe link can be adjusted to adjust the toe-in. Load-bearing links on which the suspension spring is supported are called spring links . Crank arms have two parallel swivel joints or a swivel and a ball joint like a wishbone. The Panhard rod is a rod guide that supports the transverse forces on rigid axles .

A control arm reduces the wheel carrier's degree of freedom from originally six (three degrees of freedom with respect to position and three with respect to orientation) by one, a triangular control arm or a swivel arm by two, and a trapezoidal arm by four. If five link arms are connected to the wheel carrier, a degree of freedom remains that is required for an independent wheel suspension . For the kinematically exact guidance of a rigid axle with two degrees of freedom, four rod guides are required.

The handlebars are usually connected to the vehicle body via rubber bearings in order to decouple noises and to achieve steering effects that are desirable for driving dynamics. When wishbones are therefore z. B. used on the base rubber bushings whose axes of rotation are aligned. Ball joints are usually required on the wheel carrier on the front axle because of the wheel angle. Handlebars that only have to transmit moments about one axis are designed to be flexible and are used in different ways, e.g. B. referred to as a sword handlebar. Missing degrees of freedom of the joints are compensated for by bending and torsion of the handlebar. An example is the trailing arm (longitudinal thrust strut) on the rear swing axle of the VW Beetle .

literature

  • Wolfgang Matschinsky: Wheel guides of road vehicles: kinematics, elasto-kinematics and construction . 2nd Edition. Springer, 1998, ISBN 978-3-662-09653-6 , pp. 8–9 ( limited preview in Google Book search).
  • Andreas Steimel: Electric traction vehicles and their energy supply: Basics and practice . 2nd Edition. Oldenbourg Industrieverlag Munich, 2006, ISBN 978-3-8356-3090-1 , p. 20 ( limited preview in Google Book search).

Individual evidence

  1. Stefan Gössner: Gear theory: vector analysis of plane mechanisms . 4th edition. Logos Verlag Berlin, 2012, ISBN 978-3-8325-3082-2 , p. 155 ( limited preview in Google Book search).
  2. ^ Knauer's big book on the car, Droemer Knaur Verlag Schoeller & Co, Ascona 1980, ISBN 3-85886-089-1 , page 195
  3. Metin Ersoy, Stefan Gies (Ed.): Chassis Manual: Basics, Driving Dynamics, Driving Behavior, Components, Electronic Systems, Driver Assistance, Autonomous Driving, Perspectives . 5th edition. Springer Vieweg, 2017, ISBN 978-3-658-15467-7 , pp. 543 ( limited preview in Google Book search).
  4. Bernd Heißing, Metin Ersoy, Stefan Gies: chassis manual . 4th edition. Springer Vieweg, 2013, ISBN 978-3-658-01992-1 , p. 438 ( limited preview in Google Book search).