Piezoelectric crystal fuel injector driving circuit

Abstract

The invention provides a piezoelectric crystal fuel injector driving circuit. On the basis of MC33816, IRS2101 is used for improving the maximum driving voltage capacity of the MC33816, and meanwhile, the functions of hardware current closed loop / fault protection and the like of the MC33816 are used for achieving driving of a piezoelectric crystal fuel injector; an inductor L is connected in series in a charge-discharge loop of a piezoelectric crystal; due to the energy storage effect of the inductor, energy can be transferred to a capacitor through the inductor in the charge-discharge process, so that the current change rate is reduced; and when the current change rate is reduced, the current control precision is correspondingly improved, the MOS control frequency is reduced, and the circuit reliability is improved.

Description

technical field [0001] The invention mainly relates to the field of driving circuits of piezoelectric crystal fuel injectors, in particular to the driving circuit of piezoelectric crystal fuel injectors. Background technique [0002] As emission regulations become more and more stringent, continuously increasing the injection pressure has become an indispensable means of diesel engine injection control. At present, the injection peak pressure required by the diesel engine fuel supply system has been increased from 500Pa to 1600Pa, and the common rail system has reached 2000Pa. [0003] There are two commonly used common rail systems, electromagnetic and piezoelectric. The piezoelectric common rail system has developed rapidly in recent years due to its short response time, high driving pressure and precise control of fuel injection volume, which is superior to the electromagnetic common rail system. , has good development prospects. [0004] Piezoelectric crystals are equiv...

AI Technical Summary

Problems solved by technology

[0004] Piezoelectric crystals are equivalent to capacitors with fixed capacitance. The charging and discharging speed of capacitors is very fast, and it is easy to generate instantaneous large currents. The current mainstream solution uses pre-driver chips to drive piezoelectric crystal fuel injectors, and the charging current accuracy of piezoelectric crystals cannot be controlled. High, the current change rate is fast, the MOS driving frequency is too high, it is easy to generate overcurrent, and the driving circuit is easy to cause MOS damage; The circuit drive capability is low, and high voltage circuit drive cannot be realized

Images