No-load dynamometer can be divided into two test schemes according to its dynamometer principle:
1. The instantaneous acceleration measurement scheme is an instrument scheme to obtain instantaneous power by measuring the acceleration of a certain speed during acceleration. The instrument designed in this project consists of sensor, pulse shaper, time signal generator, acceleration calculator and control device, conversion analyzer, conversion switch, power indicator, tachometer and power supply.
Working principle: The electromagnetic induction sensor is installed in a special processing hole on the clutch housing, and keeps a gap of 2~4mm with the tooth tip of the flywheel gear ring, so it is a non-contact sensor. When the flywheel rotates, the sensor generates a pulse signal. The frequency of the pulse is the number of teeth of the flywheel gear ring multiplied by the number of revolutions per second of the flywheel, that is, the number of teeth of the flywheel gear ring, which is the speed signal of the engine. The pulse signal from the sensor is shaped and amplified by the pulse shaping device to become a rectangular trigger pulse signal. The frequency of the pulse signal is usually amplified by 2-4 times.
2. The measurement scheme of acceleration time is to obtain the average acceleration power by measuring the acceleration time within a certain speed range during the acceleration process. The scheme consists of speed signal sensor, pulse shaping loading, start speed trigger, end speed trigger, time signal generator, calculation control device and display device.
The instrument can take the electric shock closing primary current induction signal of the primary circuit breaker of the ignition system as the engine speed pulse signal, which is shaped into a rectangular waveform by the shaping circuit and converted into an average voltage signal. When the throttle valve of the engine suddenly opens and the speed reaches the initial speed, the corresponding voltage signal triggers the calculation control circuit through the trigger, so that the time signal enters the calculator and is recorded; When the engine accelerates to the final speed, the corresponding voltage signal triggers the calculation control circuit through the trigger, and the stop time signal enters the calculator. The number of time pulses in the register is converted into current signals through A/D, and the acceleration time is displayed on the indicator or the success rate is directly calibrated.
Million car purchase subsidy