Camshaft Drive Torque Measuring Device Built in a Chain Sprockt

Abstract

A device built in a camshaft drive chain sprocket for detecting precise torque fluctuation with minimum change on the valve drive system dynamical characteristics was developed. Strain gages are placed on thin plate areas in the sprocket disc. The signal from the circuit goes through frequency modulation and is transmitted to demodulation circuit via coil antennas. By this arrangement, almost perfect linearity was observed in the relationship of the output voltage and the applied torque. Torque fluctuation measured with this device on a model cylinder head driven by a variable speed motor showed good correlation with simulation results.