CRANK ANGULAR VELOCITY MEASURING DEVICE AND MISFIRE DETECTION DEVICE

• Main Authors: UTSUGI, Katsuhiro, KISHI, Nobuyuki, FUKAYA, Shuichi, TAJIMA, Katsuki
• Format: Patent
• Language: English; French; German
• Published: 01.12.2021
• Subjects: BLASTING; COMBUSTION ENGINES; CONTROLLING COMBUSTION ENGINES; HEATING; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT; LIGHTING; MEASURING; MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION,OR SHOCK; MECHANICAL ENGINEERING; PHYSICS; TESTING; WEAPONS

An AC rotary electric machine (M) such as a starter motor rotates synchronously with the crankshaft and is provided with a rotor in which S-pole and N-pole permanent magnets (60) are arranged circumferentially, and with first, second, and third magnetic sensors (61) that detect a magnetization boundary between the permanent magnets. The sensors are arranged that they provide phase shifted signal edges in response to the passing of the magnetization boundaries. A clocking means (51a, 51b, and 51c) counts a first elapsed time from detection of a particular magnetization boundary by a first magnetic sensor (61a) to detection by a second magnetic sensor (61b), a second elapsed time from detection of the magnetization boundary by the second magnetic sensor (61b) to detection by a third magnetic sensor (61c), and a third elapsed time from detection of the magnetization boundary by the third magnetic sensor (61c) to detection of the next boundary by the first magnetic sensor (61a). A moving average calculating means (52) calculates the crank angular velocity based on a moving average of the first, second, and third elapsed times, which only depends on the duration of a cycle of the signal generated by a respective one of the three magnetic sensors.