Rolling road test of vehicle brakes - utilises piezo-electric element coupled to jack activated by beam on roller which receives braking force from wheel

摘要

The brakes of a car are checked via the wheels and rollers. A piezo resistive element between jack assemblies and the rollers ensures that the braking effort is recorded with a time response which is independent of temp. Pairs of rollers (1-4) for vehicle wheels are driven by axles (6) and chains (5) from an electric motor (7) and gear assembly (8). A beam (11) on each gear assembly receives the braking force from the partic. wheel. This action is applied to hydraulic jacks (15) to which piezoelectric elements (16) are coupled. These elements are connected to amplifier circuits (17) powered from stabilised power supplies (18). The amplifier outputs drive recording instrumentation (21) in which a pointer (22) moves over a scale to indicate braking effort.