A System for the precise determination of crankshaft angular position for fuel self-ignition, especially in the cylinder of diesel engine using Langmuir probe

A system for monitoring of the fuel self-ignition angle, especially in the cylinder of a diesel engine applying Langmuir probe is described. A two-channel metal adapter (2) with pressure indicator (6) and Langmuir probe (3) is placed in an engine cylinder(1). In the indicator channel a pressure sensor (7) is placed, which generates a signal which is sent to the electronic pressure recorder (10). Langmuir probe (3) is connected with a power source (4) and signal amplification set-up (5), which is connected with the fuel self-ignition angle recorder (13). The monitoring system includes the Top Dead Centre (TDC) signal generator (8), which signal is transmitted to the TDC signal divider (9), which after galvanic separation is transmitted to the electronic pressure recorder (10), the vibration recorder (11), the crankshaft revolution timer (12) and the self-ignition angle recorder (13). The vibrational sensor (16), sends its signals to the vibration recorder (11) but the signal from the self-ignition angle recorder (13) is sent to numerical indicator of self-ignition angle (15) and the signal determining the value of angular velocity to its numerical indicator (14); finally, export of data from the self-ignition angle recorder (13) is performed through data transmission set-up (17) to external monitoring systems. An alternative system for monitoring of the fuel self-ignition angle (presented in Fig. 2) contains a pulsed, rotating transducer (18) generating 3600 pulses per crankshaft revolution (0,1 ° CA) - replacing less precise determination of TDC by an inductive sensor. The rotating transducer (18) generates TDC signal, which is transmitted to the signal divider (9). Advantage of the invented monitoring system is placement of the Langmuir probe in engine cylinder, which enable direct determination of moment of fuel ignition in working engine.