Method of and equipment for qualifying shock absorbers of a motor vehicle

Abstract

A method and equipment for qualifying shock absorbers of motor vehicles including the placing of the wheels of the vehicle on suitable supports, measuring the static contact force acting standstill, imposing a forced constant amplitude sinusoidal vibration to, and exceeding the natural resonance frequency of the chassis, then removing this excitation and measuring the contact force as a function of the changing frequency. The positioning of the wheels are checked before the forced vibration, then when the frequency drops below natural frequency, one wheel is vibrated at natural frequency of the chassis by holding the frequency of forced vibration to that value, and at that frequency the minimum contact force is measured, then the value characteristic of the applied shock absorber is determined from the static contact force and minimum contact force. The apparatus has a supporting member to transfer the swinging motion to the wheel of the vehicle chassis, a force-sensing unit coupled to the supporting member, an electronic measuring unit to receive the signals of the force-sensing unit and a unit to check proper adjustment of the pair of wheels, wherein the electronic measuring unit includes dynamometers indicating the forces arising in the supporting member coupled to each unit of the pair of wheels, and a control processor unit to process the output signals of the dynamometers.