⑴ Electro-Hydraulic throttle Electro-hydraulic throttle, most of which is used in construction machinery with hydraulic system. It has the characteristics of simple structure, low cost, large driving force, low power consumption and so on, and its electro-hydraulic control conversion is mainly realized by high-speed switch digital valve, high control precision, not too high requirements for hydraulic oil. However, due to the fluctuation of oil supply pressure in the hydraulic system, the friction between the hydraulic actuator and the opening and closing characteristics of the valve, the position response is not accurate and the speed response is slow.
As a result, electro-hydraulic throttle is rarely used in cars.
⑵ Linear electromagnet Throttle The electromagnetic iron throttle uses proportional electromagnet as the controller. It uses magnetism as the driving force, in which the control signal is the current signal, with simple structure, small size, convenient control, fast response speed, good steady-state accuracy, but its maximum force is limited by the number of coil turns and the maximum operating current, and the required power consumption under a certain workload is relatively large.
As a result, linear electromagnetic throttle is rarely used in automobiles.
⑶ Stepper Motor Throttle Stepper motor throttle through the stepper motor directly drive the throttle shaft to achieve throttle opening control. The drive stepper motor usually adopts the bridge circuit structure, and the control unit controls the stepper motor by the number of pulses emitted, the frequency and the direction control level. Stepper motor has the advantages of simple structure, high reliability and low cost, but its control accuracy is not high.
As a result, stepper motor-type throttle is also less used in automobiles.
⑷ DC servo Motor type throttle DC servo motor adopts pulse width modulation (PWM) technology, which is characterized by high frequency, high efficiency, high power density and high reliability. The control unit controls the size of the DC motor Corner by adjusting the duty-free ratio of the pulse width modulation signal. In addition, the motor output torque is proportional to the duty-free ratio of the pulse width modulation signal.
Because of the above advantages, DC servo motor is widely used in electronic throttle control.