METHOD FOR DETECTING INTERNAL PRESSURE OF CYLINDER OF ROTARY PISTON ENGINE

PURPOSE:To make it possible to detect the internal pressure of a cylinder without requiring a plurality of cylinder internal pressure sensors and complicated calculation, by calculating the internal pressure of the cylinder in an actual measurement impossible process on the basis of the cylinder internal pressure value detected in an actual measurement possible process and the volumetric change characteristics of an operation chamber. CONSTITUTION:A rotor 4 is eccentrically rotated in a housing 2 and the specific operation chamber 51 demarcated by one side 41 of the rotor 4 reaches an intake lower dead point. Because a cylinder internal pressure sensor 8 is faced to the interior of the operation chamber 51 at this time, the detection of the cylinder internal pressure of the operation chamber 51 by the sensor 8 is started. The detection of the cylinder internal pressure of the operation chamber 51 by the sensor 8 is continuously performed until the operation chamber 51 passes the sensor 8 by further rotating the rotor 4 by about 120 deg.. As mentioned above, an output shaft 3 is rotated by about 360 deg. during a time when the rotor 4 rotates by about 120 deg. and, during this time, a gaseous mixture is ignited by an ignition plug to take an expansion process. A cylinder internal pressure curve is obtained by applying zero point correction to the pressure wave form, which is obtained on the basis of the cylinder internal pressure signal (a) inputted to an operation unit 10 from the sensor 8, on the basis of the intake pressure signal (b) inputted to the unit 10 from an intake sensor 9.