Driving current control circuit of piezoelectric ceramic diesel injector

Abstract

The invention relates to a driving current control circuit of a piezoelectric ceramic diesel injector. The driving current control circuit of the piezoelectric ceramic diesel injector comprises a first processor and a piezoelectric ceramic executor, wherein the high-voltage end of the piezoelectric ceramic executor is connected with the source electrode end of a high-voltage charging switch tube T1 and is connected with the drain electrode end of a discharge switch tube T2; the source electrode end of the discharge switch tube T2 is grounded; the low-voltage end of the piezoelectric ceramic executor is connected with a sampling threshold value processing circuit for sampling working current of the piezoelectric ceramic executor; the sampling threshold value processing circuit is connected with a current control circuit; the current control circuit is connected with the grid electrode end of the high-voltage charging switch tube T1 and the grid electrode end of the discharge switch tube T2 through a driving logic circuit respectively. The driving current control circuit of the piezoelectric ceramic diesel injector is compact in structure, and can accurately control driving current so as to ensure the consistency of the driving current, reduce the switching loss and improve the reliability of an electric control system.

Description

technical field [0001] The invention relates to a driving current control circuit, in particular to a driving current control circuit of a diesel engine piezoelectric ceramic fuel injector, belonging to the technical field of diesel engine piezoelectric ceramic fuel injection systems. Background technique [0002] For diesel injectors, Siemens was involved in the piezoelectric system drive earlier, and first proposed the basic drive structure; BOSH combined with the vehicle system, proposed many optimization schemes for actual control, etc.; current control schemes generally use variable PWM drive, For controlling the driving process from small pulses to larger pulses, references such as US8074626B2, JP04615967B2; or variable duty cycle control PWM drive mode, references such as EP1772952B1. The current control method is basically directly coupled with PWM after hardware sampling and comparison. In extreme cases (such as high-speed multiple injection requirements) the heat l...

AI Technical Summary

Problems solved by technology

Even if there is current control, the basic current control is realized through the voltage feedback based on the sampling resistor and the PWM control of the MCU, and the accuracy of the current control is limited.

However, domestic actuators cannot withstand high current impacts at present, and more precise control of the current is required.

Some schemes also use sampling resistor feedback to control the current, but when the current is controlled at a lower value, the system loss is large, the heat is serious, there is no transition coupling of the latch, the switching frequency is high, the device heats up seriously, and the electromagnetic interference is relatively high. serious

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