Experimental Study and Hardware Design of Diesel Engine Valve Timing Detection Based on Cylinder Cover Vibrations

To design an on-line detection device for diesel engine valve timing, experiment was firstly carried out to take measures of vibration signals on the top of exhaust valve cage and phase signal on flywheel end of a two-stroke marine diesel engine. The signals were then analyzed and a new method was put forward for on-line detection of valve opening and closing timing based on the cylinder cover vibration signals. Finally, a set of valve timing detection hardware is designed with single chip microcomputer technology of AD7606 and STM32, including ICP driving circuit and signal conditioning circuit of magnetoelectric sensors. The device adopts STM32 as the main control chip with 8 channels of 16-bit synchronous sampling inputs. Its sampling range is between ± 10 volts and ± 5 volts optionally with up to 200ksps data throughput. This device can realize online detection of intake and exhaust valve timing and online condition monitoring of valve train for different type of diesel engines.