Generation method and apparatus for electromagnetic valve driving current

Abstract

The invention discloses a generation method and a device for a solenoid pilot actuated valve drive current, and is applicable to a fuel injection system of an engine. The method has the following steps: a high-end drive circuit is connected with one end of a solenoid pilot actuated valve via a sampling resistor; a low-end drive circuit is connected with the other end of the solenoid pilot actuated valve; an electronic control unit sends a summit current holding control pulse signal AH and a current feedback control pulse signal AF to a signal processing circuit, and a low-end drive circuit control pulse signal B to the low-end drive circuit; and the signal processing circuit compares the solenoid pilot actuated valve drive current fed back by the sampling resistor with a current corresponding to a reference voltage, and sends a control signal C to the high-end drive circuit. By adopting the technical scheme, the method and the device of the invention have the advantages of short opening time of the solenoid pilot actuated valve, simple and reliable hardware current feedback control circuits, high regulating frequencies, good anti-interference effect in use, low price and the total production cost.

Description

technical field [0001] The invention relates to the technical field of electronically controlled engine fuel injection, in particular to a method and device for generating a driving current of an electromagnetic valve. Background technique [0002] In the electronically controlled engine fuel injection system, there are very strict requirements on the opening and closing of the solenoid valve. Since the opening and closing of the solenoid valve are closely related to the driving current, it is necessary to precisely control the driving current to realize the solenoid valve action. . [0003] figure 1 Is the schematic diagram of the solenoid valve drive current waveform. Such as figure 1 As shown, in the engine electromagnetic bypass valve control technology, the driving current is generally required to be in the form of figure 1 The two-stage drive current shown, T1 refers to the current boost stage, T2 current peak hold stage, T3 low current hold stage, the solenoid val...

AI Technical Summary

Problems solved by technology

The traditional driving structure generally connects a freewheeling diode between the two ends of the solenoid valve or between the emitter of the low-end power triode and the high-end of the solenoid valve. The capacity remains unchanged, resulting in a slow decline in the driving current, and the solenoid valve is not disconnected quickly. The latter cuts off the freewheeling circuit after the low-end power transistor is turned off, and the induced current has no place to discharge, causing the low-end power transistor to be easily damaged.

[0008] Furthermore, the reliability is not strong

In the traditional solenoid valve drive circuit, the sampling resistor is often located between the emitter of the low-end power triode and the power ground. This connection method cannot effectively suppress the interference on the power ground line, and the sampling voltage is generally less than 1V, so the sampling voltage is affected by interference. More obvious, weaker control reliability

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