阅读说明：本技术 喷油器驱动电路 (Oil sprayer driving circuit ) 是由 谢宏斌 张爱云 张美娟 杨勇 于 2019-11-22 设计创作，主要内容包括：本发明公开了一种喷油器驱动电路,包括电流采样电路和微控制器,电流采样电路实时采集喷油器的驱动电流值,微控制器触发AD转换模块获取喷油器的驱动电流值；TPU单元比较当前状态下喷油器的驱动电流值与目标驱动电流值,并根据比较结果调节驱动电流特征值；CPLD根据上一周期调整后的电流特征值和输入驱动使能信号生成调制输出脉冲；调制输出脉冲控制高、低端驱动电路调节喷油器本周期的驱动电流,使得喷油器的驱动电流值趋近目标驱动电流值。本发明的喷油器驱动电路,可以适应不同型号的喷油器驱动而不需要修改硬件参数,并自动校正因为喷油器长期使用导致的驱动波形差异,确保驱动电流的一致性,提高喷油器喷油的稳定性,延长喷油器电磁阀的使用寿命。(The invention discloses a fuel injector driving circuit which comprises a current sampling circuit and a microcontroller, wherein the current sampling circuit is used for acquiring the driving current value of a fuel injector in real time, and the microcontroller triggers an AD conversion module to acquire the driving current value of the fuel injector; the TPU unit compares the driving current value of the oil sprayer in the current state with a target driving current value and adjusts the characteristic value of the driving current according to the comparison result; the CPLD generates modulation output pulses according to the current characteristic value adjusted in the previous period and the input drive enabling signal; the modulation output pulse controls the high-end driving circuit and the low-end driving circuit to adjust the driving current of the oil sprayer in the period, so that the driving current value of the oil sprayer approaches to the target driving current value. The oil sprayer driving circuit can adapt to the driving of oil sprayers of different models without modifying hardware parameters, automatically corrects the driving waveform difference caused by the long-term use of the oil sprayer, ensures the consistency of driving current, improves the oil spraying stability of the oil sprayer and prolongs the service life of an electromagnetic valve of the oil sprayer.)

1. A fuel injector driving circuit comprises a CPLD, a high-end driving circuit, a low-end driving circuit, high-end switching tubes M1 and M2, a low-end switching tube M3, a resistor R, a diode D1 and a diode D2; the CPLD is respectively connected with a high-end driving circuit and a low-end driving circuit, two output ends of the high-end driving circuit are respectively connected with control ends of a high-end switch tube M1 and a high-end switch tube M2, a current input end of the high-end switch tube M1 is connected with a Boost power supply, a current output end of a high-end switch tube M1 is connected with an anode of a diode D1, a cathode of a diode D1 and a cathode of a diode D2 are both connected with input ends of an oil sprayer, an output end of the oil sprayer is connected with a current input end of a low-end switch tube M3, and a current output end of a low-; the current input end of the high-end switch tube M2 is connected with the battery voltage, and the current output end of the high-end switch tube M2 is simultaneously connected with the cathode of the diode D1, the cathode of the diode D2 and the current input end of the oil sprayer; the output end of the low-end driving circuit is connected with the control end of the low-end switching tube M3; the anode of the diode D2 is grounded; the method is characterized in that: it also includes a current sampling circuit and a Microcontroller (MCU),

the current sampling circuit is used for collecting the driving current value of the oil injector in real time;

the CPLD synthesizes AD trigger pulse according to the input signal of the microcontroller;

the output end of the current sampling circuit is connected with an AD conversion module of a microcontroller, the microcontroller receives the AD trigger pulse, and the AD conversion module is triggered at the upper edge and the lower edge of the AD trigger pulse to acquire the driving current value of the oil sprayer;

the TPU unit of the microcontroller compares the driving current value of the oil sprayer in the current state with a target driving current value, and adjusts the characteristic value of the driving current according to the comparison result, and the adjusted characteristic value of the driving current is applied to generate a current modulation signal of the next period;

the CPLD generates modulation output pulses according to the current characteristic value adjusted in the last period and the input drive enabling signal; the modulation output pulse controls a high-end driving circuit and a low-end driving circuit, and the high-end driving circuit and the low-end driving circuit adjust the driving current of the oil sprayer in the period according to the modulation output pulse, so that the driving current value of the oil sprayer approaches to a target driving current value.

2. The fuel injector drive circuit according to claim 1, characterized in that: the microcontroller is provided with a DMA memory and an RAM memory, and the AD conversion module directly transfers the driving current characteristic value of the fuel injector obtained through conversion to the RAM memory through a DMA channel of the DMA memory; and directly transferring the time value of each high pulse width and each low pulse width of the modulation output pulse acquired by the time processing unit to the RAM memory through a DMA channel of the DMA memory.

3. The fuel injector drive circuit according to claim 1, characterized in that: and the acquisition and modulation of the driving current value of the oil sprayer are carried out all the time in the operation process of the TPU unit until the driving current value of the oil sprayer is consistent with the target driving current value.

4. The fuel injector drive circuit according to claim 1, characterized in that: the microcontroller comprises a time processing unit which supports pulse input and automatically calculates the time value of each high pulse width and low pulse width of the modulation output pulse.

5. The fuel injector drive circuit according to claim 1, characterized in that: the driving current characteristic value comprises the conducting time (T0) of a high-voltage open-stage high-side switch tube M1, the conducting time (T1) of a first-stage maintaining-stage high-side switch tube M2, the turn-off time (T2) of a first-stage maintaining-stage high-side switch tube M2, the conducting time (T6) of a second-stage maintaining-stage high-side switch tube M2, the turn-off time (T7) of a second-stage maintaining-stage high-side switch tube M2, the duration (T8) of a first-stage maintaining stage, the transition time (T3) from a high-voltage open-stage current peak value to a first-stage maintaining-stage first current valley value, the transition time (T5) from a first-stage current valley value to a first-stage current peak value and the duration (T4) from the first-stage first current.

6. The fuel injector drive circuit according to claim 5, characterized in that: during the high-voltage opening stage, the high-side switch tube M1 and the low-side switch tube M3 are both turned on, and the current peak value of the high-voltage opening stage is related to the turn-on time of the high-side switch tube M1; during the first-order maintaining stage, the low-side switch tube M3 is always turned on, the high-side switch tube M2 is periodically turned on and off, the current peak value of the first-order maintaining stage is related to the turn-on time of the high-side switch tube M2, and the current valley value of the first-order maintaining stage is related to the turn-off time of the high-side switch tube M2; during the second-order maintaining stage, the low-side switch M3 is always turned on, the high-side switch M2 is periodically turned on and off, the current peak value of the second-order maintaining stage is related to the on-time of the high-side switch M2, and the current valley value of the second-order maintaining stage is related to the off-time of the high-side switch M2.

Technical Field

The invention relates to the technical field of electric control oil injectors, in particular to an oil injector driving circuit.

Background

In a common fuel injector driving circuit in the market, current regulation is mostly realized by adopting hardware regulation and using a current conditioning circuit, once the parameters are determined, online regulation can not be realized according to the parameters of the fuel injector, and the current conditioning circuit also causes complexity increase of the whole circuit. In order to meet the requirements of oil injectors of different models, the drive circuit needs to modify hardware parameters; moreover, after some fuel injectors are used for a period of time, the inductance of the electromagnetic valve is aged, parameters are scattered to a certain degree, and finally large differences of driving currents are caused, and hardware parameters are required to be modified to deal with the situations. The above application limitations make the conventional driving circuit inflexible in application and high in design and maintenance costs.

Disclosure of Invention

The invention aims to solve the technical problem of providing an oil injector driving circuit which can adapt to the driving of oil injectors of different models without modifying hardware parameters, automatically correct the driving waveform difference caused by long-term use of the oil injectors, ensure the consistency of driving current, improve the oil injection stability of the oil injectors and prolong the service life of electromagnetic valves of the oil injectors.

In order to solve the technical problem, the invention provides an injector driving circuit, which comprises a CPLD, a high-side driving circuit, a low-side driving circuit, high-side switching tubes M1 and M2, a low-side switching tube M3, a resistor R, a diode D1 and a diode D2; the CPLD is respectively connected with a high-end driving circuit and a low-end driving circuit, two output ends of the high-end driving circuit are respectively connected with control ends of a high-end switch tube M1 and a high-end switch tube M2, a current input end of the high-end switch tube M1 is connected with a Boost power supply, a current output end of a high-end switch tube M1 is connected with an anode of a diode D1, a cathode of a diode D1 and a cathode of a diode D2 are both connected with input ends of an oil sprayer, an output end of the oil sprayer is connected with a current input end of a low-end switch tube M3, and a current output end of a low-; the current input end of the high-end switch tube M2 is connected with the battery voltage, and the current output end of the high-end switch tube M2 is simultaneously connected with the cathode of the diode D1, the cathode of the diode D2 and the current input end of the oil sprayer; the output end of the low-end driving circuit is connected with the control end of the low-end switching tube M3; the anode of the diode D2 is grounded; it also includes a current sampling circuit and a Microcontroller (MCU),

the current sampling circuit is used for collecting the driving current value of the oil injector in real time;

the CPLD synthesizes AD trigger pulse according to the input signal of the microcontroller;

the output end of the current sampling circuit is connected with an AD conversion module of a microcontroller, the microcontroller receives the AD trigger pulse, and the AD conversion module is triggered at the upper edge and the lower edge of the AD trigger pulse to acquire the driving current value of the oil sprayer;

the TPU unit of the microcontroller compares the driving current value of the oil sprayer in the current state with a target driving current value, and adjusts the characteristic value of the driving current according to the comparison result, and the adjusted characteristic value of the driving current is applied to generate a current modulation signal of the next period;

the CPLD generates modulation output pulses according to the current characteristic value adjusted in the last period and the input drive enabling signal; the modulation output pulse controls a high-end driving circuit and a low-end driving circuit, and the high-end driving circuit and the low-end driving circuit adjust the driving current of the oil sprayer in the period according to the modulation output pulse, so that the driving current value of the oil sprayer approaches to a target driving current value.

In a preferred embodiment of the present invention, the microcontroller further includes a DMA memory and a RAM memory, and the AD conversion module directly transfers the obtained characteristic value of the driving current of the injector to the RAM memory through a DMA channel of the DMA memory by conversion; and directly transferring the time value of each high pulse width and each low pulse width of the modulation output pulse acquired by the time processing unit to the RAM memory through a DMA channel of the DMA memory.

In a preferred embodiment of the present invention, the acquisition and modulation of the driving current value of the injector are performed all the time in the operation process of the TPU unit until the driving current value of the injector is consistent with the target driving current value.

In a preferred embodiment of the present invention, the microcontroller further comprises a time processing unit, the time processing unit supports pulse input and automatically calculates a time value of each of a high pulse width and a low pulse width of the modulation output pulse.

In a preferred embodiment of the present invention, the characteristic value of the driving current further includes an on time T0 of the high-side switch M1 in the high-voltage open phase, an on time T1 of the high-side switch M2 in the first-order maintaining phase, an off time T2 of the high-side switch M2 in the first-order maintaining phase, an on time T6 of the high-side switch M2 in the second-order maintaining phase, an off time T7 of the high-side switch M2 in the second-order maintaining phase, a duration T8 in the first-order maintaining phase, a transition time T3 from a peak value of the high-voltage open phase to a valley value of the first-order maintaining phase, a transition time T5 from the first-order current to the second-order current, and a duration T4 from a valley value of the first-order maintaining phase to a peak value of the last-order maintaining.

In a preferred embodiment of the present invention, the high-side switch M1 and the low-side switch M3 are both turned on during the high-voltage open phase, and the peak current value during the high-voltage open phase is related to the on-time of the high-side switch M1; during the first-order maintaining stage, the low-side switch tube M3 is always turned on, the high-side switch tube M2 is periodically turned on and off, the current peak value of the first-order maintaining stage is related to the turn-on time of the high-side switch tube M2, and the current valley value of the first-order maintaining stage is related to the turn-off time of the high-side switch tube M2; during the second-order maintaining stage, the low-side switch M3 is always turned on, the high-side switch M2 is periodically turned on and off, the current peak value of the second-order maintaining stage is related to the on-time of the high-side switch M2, and the current valley value of the second-order maintaining stage is related to the off-time of the high-side switch M2.

The invention has the beneficial effects that:

the oil atomizer driving circuit always keeps the consistency of the oil atomizer driving current through current closed-loop regulation, can adapt to the driving of oil injectors of different models without modifying hardware parameters, automatically corrects the driving current difference caused by the long-term use of the oil injectors, improves the oil injection stability of the oil injectors and prolongs the service life of electromagnetic valves of the oil injectors.

Drawings

FIG. 1 is a schematic circuit diagram of a fuel injector driver circuit in accordance with a preferred embodiment of the present invention;

FIG. 2 is a phase diagram of injector drive current and the corresponding sets of signals.

Detailed Description

The present invention is further described below in conjunction with the following figures and specific examples so that those skilled in the art may better understand the present invention and practice it, but the examples are not intended to limit the present invention.