压电直接控制式喷油器的工作原理是怎样的?发表时间:2023-06-07 11:31 The basic working principle of piezoelectric injectors is as follows: ① The nozzle needle valve is controlled by a servo valve, and the amount of fuel injected is determined by its controlled duration. ② The working principle of the piezoelectric actuator mainly relies on the inverse piezoelectric effect, where multiple layers of piezoelectric crystals elongate and produce displacement under the action of voltage. It remains in its original position when not in operation (no control signal), with the servo valve closed and the high-pressure range and low-pressure range isolated from each other. At this time, the hydraulic linkage compensates for possible gaps (due to thermal expansion, for example), and the nozzle remains closed with the help of the rail pressure and the spring next to the control chamber. ③ When a control signal (i.e., applying voltage) is applied to the piezoelectric actuator, it elongates and produces displacement, opening the servo valve and reducing the pressure in the control chamber. This lifts the needle valve with the rail pressure, opening the nozzle. It remains open until the control signal ends, and the piezoelectric actuator returns to its original length, with the servo valve closed and the pressure in the control chamber increasing, causing the needle valve to close. |