A probe assembly for internal combustion engines.

摘要

A probe assembly (10) for injection of microwave energy into the cylinder cavity of a diesel engine (19) and detection of luminescence indicative of fuel ignition in the cylinder. The probe assembly (10) comprises a probe (12) with microwave and optical transmitters (30, 28) extending axially therethrough adapted to be threaded into a cylinder opening. A coupler (14) is removably mounted on the probe (12) and includes an optical detector (58) mounted in assembly coaxially with the optical transmitters (28) in the probe and a microwave antenna (68) coupled by a waveguide cavity (52) within the coupler to the probe microwave transmitter (20). The coupler (14) is adapted for connection to suitable external diagnostic circuitry (15) for providing to such circuitry signals indicative of piston position within the cylinder and fuel ignition as a function of the microwave and luminescence signals respectively.