Aktive Sekundärmaßnahmen zur Vermeidung von fahrzustandsabhängigen Geräuschen in hydraulischen Lenksystemen

• Noise prevention in hydraulic power steering systems

Verkoyen, Torsten; Murrenhoff, Hubertus (Thesis advisor)

Aachen : Shaker (2009)
Dissertation / PhD Thesis

In: Reihe Fluidtechnik : D 53
Page(s)/Article-Nr.: V, 112 S. : Ill., graph. Darst.

Zugl.: Aachen, Techn. Hochsch., Diss., 2009

Abstract

In hydraulic power steering systems of motor vehicles, often unintended acoustic phenomena can result from certain driving situations. The acoustic phenomenon known as "rattling" is generated by impacts on the steering cylinder, if the car rides over bumps, kerb stones or similar obstacles. In special friction conditions between tyre and road surface during parking, a phenomenon called "shuddering" occurs and leads to strong vibrations. These are audible by the driver as noise, and sensory through shaky steering wheel torque. In this PhD thesis the reasons for rattling and shuddering are analysed. The design of two test benches afford easy access to the steering systems´ components and allow measurement equipment to be easily installed. Furthermore, the development of simulation models are used to study different hydraulic line designs of the steering system. With the simulation models, physical data can be calculated, which can not be measured at the test benches. A comparison between measured and simulated data then verifies the simulation models. To evaluate measured and simulated data of different hydraulic line designs, characteristic numbers are calculated and compared. Active components, to eliminate both phenomena, are worked out systematically and structured in a matrix of principle solutions. The choice of an intelligent switch element out of the matrix leads to the design of three prototype valves, which are installed in the hydraulic lines of the power steering system and analysed at the two test benches. Characteristic numbers of the three valve lines are calculated and compared to the hydraulic line of the series. With the designed valve lines the rattling and shuddering problem can be solved.

Institutions

• Chair and Institute for Fluid Power Drives and Systems [412810]