Electromagnetic valve drive circuit for engine

Abstract

The circuit contains a single processing circuit, it receives the control pulse. A from the electronic control unit of the motor and output high voltage driving pulse Ah and low voltage driving pulse Al to higher extreme driving circuit separately and receive the feedback sampling current signal from lower extreme driving circuit, after processing, the low voltage driving pulse Al adjust the higher extreme driving circuit to adjust the driving circuit of the electromagnetic valve. Lower extreme driving circuit receive pulse signal B from electronic control unit of the motor, this pulse signal is same with the control signal A.

Description

technical field [0001] A solenoid valve driving circuit for an engine relates to the driving of an electromagnetically controlled bypass valve in an electronically controlled diesel engine fuel injection system, and can be used in the related technical field of solenoid valve driving. Background technique [0002] In the electronically controlled engine injection system, there are strict requirements on the closing action of the solenoid valve. Since the closing action of the solenoid valve is closely related to the driving current, the solenoid valve action is mostly realized by precisely controlling the driving current. It is particularly obvious in the drive of the engine solenoid valve. The drive current often requires a two-stage drive current as shown in Figure 4. The solenoid valve is at T 1 and T 2 The closing action is completed within the time period, and at T 3 The time period remains closed until the end. In order to obtain this type of drive current, some dri...

AI Technical Summary

Problems solved by technology

In the high-end and low-end drive circuits, since the hardware circuit only provides the drive current feedback value, the control actions such as sampling and comparing the drive current and adjusting the duty cycle of the high-end power transistor control pulse must be completed by software. This control method is called It is called software current feedback control. The programming of the control software is very complicated, and the adjustment frequency of the duty cycle is also very low, generally not exceeding 100Hz. Such a low feedback control frequency will inevitably lead to large current fluctuations and low control accuracy.

It can be seen that the traditional driving circuit needs to be improved in terms of driving ability and control accuracy.

Images