Electronic throttle control accelerator pedal mechanism with mechanical hysteresis provider

Abstract

A control pedal assembly for a motor vehicle includes a support structure, a pedal arm pivotally mounted to the support structure and carrying a pedal, and a sensor for detecting rotation of the pedal arm and sending an electrical signal to a control device indicating the rotation of the pedal arm. The pedal assembly also includes a hysteresis device adapted to generate a desired feel in response to pivotal movement of the pedal arm. The hysteresis device is secured to the support structure and includes a plunger engaging the pedal arm and is movable within a chamber between an extended position and a depressed position upon rotation of the pedal arm. A pair of coaxial compression springs resiliently bias the plunger to the extended position. The chamber forms a first friction surface and the plunger has a plurality of prongs forming a second friction surface engagable with the first friction surface to resist pivotal movement of the pedal arm. Friction between the first and second friction surfaces, that is resistance to movement of the plunger, increases as the plunger moves from the extended position toward the depressed position. Variable friction is obtained because the prongs form angled surfaces engaging the spring for wedging the prongs in a radially outward direction to engage the first and second friction surfaces together with increasing force as the springs are compressed.