GF07.15-W-4005A | Determination of the engine speed and crankshaft angle, function | 4.7.07 |
ENGINE 904.9 in MODEL 375.1 with BODY 375.830
ENGINE 904.9 in MODEL 970, 972, 975, 976 with BODY 972.899
ENGINE 906.9 in MODEL 970, 972, 974, 975, 976 with BODY 972.899
ENGINE 906.9 in MODEL 375.3 with BODY 375.810
ENGINE 906.9, 926.9 in MODEL 950, 952, 953, 954 with BODY 940.899
W07.15-1342-78
1 Flywheel
2 Bores - to detect the engine speed
A6 MR/PLD control unit
B15 Crankshaft angle position sensor
3 An additional bore - to detect the crankshaft angle
The engine speed is taken from the flywheel (1) on the crankshaft. To do this there are 36 evenly distributed bores (2) around the circumference of the flywheel (1), that is at a distance from each other respectively of 10°.
Each of these bores (2) triggers an impulse in the crankshaft position sensor (B15). An additional bore (3) is located at a 65° crankshaft angle before the top dead center (OT) of cylinder 1. It delivers a characteristic additional impulse. This means that not only the engine speed but also the angular position of the crankshaft can be determined at any time.
The MR/PLD control unit (A6) starts an internal counter (trigger) once it receives an impulse from the crankshaft position sensor (B15). Calculations yield the crankshaft position and the engine speed.
Calculation of the intermediate values makes it possible for the engine control (MR) to exactly determine the start of injection and the period of injection to a fraction of a degree.