Fig. 13-4 No. 3 cylinder blocked nozzle condition
3. 6. 3 Simulation on the 4 cycle, 6 cylinder's engine
The test devices were set up on the 4 cycle, 3 cylinder's engine. However, in the multi-cylinder's engine, the ignition interval become short while the mutual effect of gas pressure become large among cylinders. For confirming how much the above facts exert to the operation results the contribution rate, the simulation was carried out on the supposition of the 6 cylinder's engine.
Fig. 14-1 25% Load
Fig. 14-2 50% Load
Fig. 14-3 75% Load
Fig. 14-4 100% Load
4. Conclusion
1. By the regular monitoring of the torsion angles of the crankshaft, the monitoring of the normal and/or abnormal conditions were made possible.
2. Even for the decrease of 5 - 10% degree in Pmax, by means of the proposed method, abnormal conditions of gas pressure in cylinder could be caught by the relative comparison of other cylinders.
3. As the torsion angle data of the measured crankshaft were very good in reproducibility, the stable data could be obtained. This means that in case of the abnormal condition diagnosis of this proposal, the sensors were free from the thermal load, no mechanical driving device and non-contact.
4. In case of sensor's method for the gas pressure in cylinder, one sensor must be fitted to each cylinder and the signals from all sensors must be analyzed. However, as the method being proposed, all cylinders could be monitored simultaneously. Therefore, it is very useful from the point of view of the simplification of the system.
5. For example, if the abnormal condition with direct ties to the vital accident such as the looseness of the crank pin bolts between the connecting rod and the crank pin bearing, it can be estimated that the different signals from the normal condition will appear on the torsion angles of the crankshaft. Of course, it is necessary to accumulate data and to develop a precise system.
