CN112879649A - Control circuit for peak holding type solenoid valve - Google Patents

Control circuit for peak holding type solenoid valve Download PDF

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Publication number
CN112879649A
CN112879649A CN202110200253.3A CN202110200253A CN112879649A CN 112879649 A CN112879649 A CN 112879649A CN 202110200253 A CN202110200253 A CN 202110200253A CN 112879649 A CN112879649 A CN 112879649A
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terminal
current
ground
switching device
signal
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CN202110200253.3A
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CN112879649B (en
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黄城健
张雷
高崴
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FAW Jiefang Automotive Co Ltd
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FAW Jiefang Automotive Co Ltd
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K31/00—Actuating devices; Operating means; Releasing devices
    • F16K31/02—Actuating devices; Operating means; Releasing devices electric; magnetic
    • F16K31/06—Actuating devices; Operating means; Releasing devices electric; magnetic using a magnet, e.g. diaphragm valves, cutting off by means of a liquid
    • F16K31/0675—Electromagnet aspects, e.g. electric supply therefor

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Mechanical Engineering (AREA)
  • Electronic Switches (AREA)

Abstract

The present invention relates to a control circuit for a peak hold type solenoid valve. The method comprises the following steps: a power supply terminal switching device having a first terminal for connection with a power supply and a second terminal for connection with a power supply terminal of the peak hold type solenoid valve; a ground terminal switching device, a first terminal of which is used for being connected with a ground terminal of the peak hold type electromagnetic valve, and a second terminal of which is used for being connected with the ground; a voltage dividing resistor connected in series between the second terminal of the power terminal switching device and the first terminal of the ground terminal switching device; a power supply terminal freewheeling diode having an anode connected to ground and a cathode connected to the second terminal of the power supply terminal switching device; the anode of the ground-end freewheeling diode is connected with the first end of the ground-end switching device, and the cathode of the ground-end freewheeling diode is used for being connected with a power supply; and one end of the energy storage element is used for being connected with a power supply, and the other end of the energy storage element is used for being connected with the ground. The circuit can provide enough voltage to drive the peak-hold type solenoid valve.

Description

Control circuit for peak holding type solenoid valve
Technical Field
The invention relates to the technical field of circuit control, in particular to a control circuit of a peak holding type electromagnetic valve.
Background
In diesel engine systems, most solenoid valves are driven with battery voltage to control the opening and closing of the solenoid valves. The driving method mainly includes two types, namely, a voltage control type and a current control type, the voltage control type is also called a saturation switch type, and the current control type is also called a peak hold type.
The drive circuit of the peak-hold type electromagnetic valve mainly comprises a freewheeling diode and at least one switching tube. Each switching tube is connected in series between the power supply end of the electromagnetic valve and the positive electrode of the storage battery or between the grounding end of the electromagnetic valve and the negative electrode of the storage battery. The anode of the freewheeling diode is connected with the grounding end of the electromagnetic valve, and the cathode of the freewheeling diode is connected with the power supply end of the electromagnetic valve. When all the switching tubes are open, the battery voltage is applied to the solenoid valve, which opens when the current rises above a threshold value. When all the switch tubes are closed, the current of the electromagnetic valve is gradually reduced under the action of the freewheeling diode, and the electromagnetic valve is closed when the current is reduced to be below a threshold value.
In practical applications, it is often necessary to simultaneously drive a plurality of solenoid valves to open, and the drive time of each solenoid valve is long in the long pulse width drive, which easily causes a low battery voltage to be applied to each solenoid valve. Particularly, when the engine is in cold start, if a plurality of electromagnetic valves are driven to open simultaneously, the voltage of the storage battery is greatly reduced, the current of the electromagnetic valve rises slowly, the opening time of the electromagnetic valve is long, and the normal work of a diesel engine system is influenced.
Disclosure of Invention
In a diesel engine system, the battery is often required to simultaneously drive a plurality of solenoid valves to open, and the drive time of each solenoid valve is long in the long pulse width drive. The battery voltage on each solenoid valve is lower at this time due to the influence of the battery performance. Further, when the battery voltage is insufficient at the time of the engine start, particularly at the time of cold start, the battery voltage at each solenoid valve is also relatively low. If the voltage of the storage battery on each electromagnetic valve is lower, the current rising speed of the battery valve is lower, and the opening time of the electromagnetic valve is longer, so that the normal work of the diesel engine system is influenced.
In view of this, it is necessary to provide a control circuit that can provide a sufficient voltage to drive the peak-hold type solenoid valve.
A control circuit for a peak-hold solenoid valve, comprising:
the power supply end switching device is used for connecting a first end with a power supply and connecting a second end with a power supply end of the peak holding type electromagnetic valve and is used for controlling the on-off of the peak holding type electromagnetic valve and the power supply;
a ground terminal switching device, a first terminal of which is used for being connected with a ground terminal of the peak holding type electromagnetic valve, and a second terminal of which is used for being connected with the ground and controlling the on-off between the peak holding type electromagnetic valve and the ground;
a voltage dividing resistor connected in series between the second end of the power terminal switching device and the first end of the ground terminal switching device, for dividing voltage with the peak hold solenoid valve;
a power supply side freewheeling diode having an anode connected to the ground and a cathode connected to the second terminal of the power supply side switching device for freewheeling to the peak hold solenoid valve when the power supply side switching device is turned off;
a ground terminal freewheeling diode having an anode connected to the first terminal of the ground terminal switching device and a cathode connected to the power supply for freewheeling the peak hold solenoid valve when the ground terminal switching device is turned off;
and the energy storage element is used for storing electric energy when the voltage of the power supply is equal to the rated voltage and/or the freewheeling diode at the power supply end and the freewheeling diode at the ground end continues current, and releasing the electric energy when the voltage of the power supply is less than the rated voltage.
In one embodiment, the method further comprises the following steps: the sampling module is respectively connected with two ends of the divider resistor and is used for measuring the voltage of the divider resistor to obtain the current of the peak holding type electromagnetic valve; the first comparison module is connected with the sampling module and used for comparing the current of the peak-hold type electromagnetic valve with the opening and closing threshold current and generating a current maintaining signal when the current of the peak-hold type electromagnetic valve is smaller than the opening and closing threshold current; and the logic element is respectively connected with the first comparison module, the control end of the power end switch device and the control end of the grounding end switch device, and is used for generating a power end switching control signal and a grounding end switching control signal based on the current maintaining signal to control the switching of the power end switch device and the switching of the grounding end switch device.
In one embodiment, the method further comprises the following steps: the single chip microcomputer is used for generating a current enabling signal according to the on-off instruction of the peak holding type electromagnetic valve; the logic element is also connected with the singlechip and is used for performing logic AND operation on the current enabling signal and the current maintaining signal to generate the power end on-off control signal and the grounding end on-off control signal.
In one embodiment, the single chip microcomputer is further configured to generate an on/off threshold current switching signal according to the switching instruction of the on/off threshold current; the first comparison module is further connected with the single chip microcomputer and used for switching the switching threshold current compared with the current of the peak holding type electromagnetic valve according to the switching threshold current switching signal.
In one embodiment, the voltage dividing resistor is connected in series between a ground terminal of the peak-hold solenoid valve and a first terminal of the ground terminal switching device; the control circuit further includes: the second comparison module is connected with the sampling module and used for comparing the current of the peak holding type electromagnetic valve with the short-circuit threshold current and generating a grounding end overcurrent indication signal when the current of the peak holding type electromagnetic valve is larger than the short-circuit threshold current; a desaturation detection module, connected to the power end switching device, for detecting a voltage between the first end and the second end of the power end switching device, and generating a power end overcurrent indication signal when the voltage between the first end and the second end of the power end switching device is greater than a desaturation threshold voltage; the logic element is further connected to the second comparing module and the desaturation detecting module, and configured to determine that a branch where the peak hold type solenoid valve is located is short-circuited when at least one of the ground terminal indication signal and the power terminal indication signal is received, and control the power terminal switching device and the ground terminal switching device to be turned off.
In one embodiment, the desaturation detection module is a driving chip, and the driving chip is connected in series between the control terminal of the power source terminal switching device and the logic element.
In one embodiment, the logic element is further configured to determine a short circuit type according to the current maintenance signal, the ground end overcurrent indication signal, and the power end overcurrent indication signal.
In one embodiment, the single chip microcomputer is further configured to generate a clock signal; the logic element is further configured to determine a duration before the generation of the ground end over-current indication signal according to the clock signal, and distinguish a short circuit type according to the duration before the generation of the ground end over-current indication signal.
In one embodiment, the logic element is further configured to determine that the branch in which the peak-hold solenoid valve is located is open when the current enable signal is received and the current maintenance signal is not received.
In one embodiment, the logic element is further configured to generate and latch an indication signal when the branch in which the peak-hold solenoid valve is located is short-circuited or open-circuited.
In the control circuit of the peak holding type electromagnetic valve, the power supply end switching device is connected in series between the power supply and the power supply end of the peak holding type electromagnetic valve, the grounding end switching device is connected in series between the grounding end of the peak holding type electromagnetic valve and the ground, and the peak holding type electromagnetic valve is opened when the power supply end switching device and the grounding end switching device are closed simultaneously. Because the divider resistor is connected in series between the power end switch device and the grounding end switch device, the voltage can be divided by the peak holding type electromagnetic valve when the power end switch device and the grounding end switch device are closed simultaneously, and the smooth change of the voltage and the current is realized in a matching manner. The positive pole of the power supply end fly-wheel diode is grounded, the negative pole of the power supply end fly-wheel diode is connected between the power supply end switch device and the peak holding type electromagnetic valve, the positive pole of the grounding end fly-wheel diode is connected between the peak holding type electromagnetic valve and the grounding end switch device, the negative pole of the grounding end fly-wheel diode is connected with the power supply, the peak holding type electromagnetic valve, the divider resistor, the power supply end fly-wheel diode and the grounding end fly-wheel diode form a branch circuit connected between the power supply and the ground, and the power supply end fly-wheel diode and the grounding end fly-wheel diode realize. Because one end of the energy storage element is connected with the power supply, and the other end of the energy storage element is grounded and is connected in parallel with a branch circuit consisting of the peak holding type electromagnetic valve, the divider resistor, the power supply end freewheeling diode and the grounding end freewheeling diode, the energy can be stored when the voltage of the power supply is equal to the rated voltage and/or the power supply end freewheeling diode and the grounding end freewheeling diode freewheel, and then the energy can be released when the voltage of the power supply is less than the rated voltage, so that the effects of timely supplementing the energy when the voltage of the storage battery is lower due to the reasons of simultaneously driving a plurality of electromagnetic valves to be opened, the driving time of the electromagnetic valves is long, the engine is just started, the engine is cold started and the.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments or the conventional technologies of the present application, the drawings used in the descriptions of the embodiments or the conventional technologies will be briefly introduced below, it is obvious that the drawings in the following descriptions are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a schematic diagram of a control circuit for a peak-hold solenoid according to one embodiment;
fig. 2 is a timing chart of signals in a control circuit of the peak-hold type solenoid valve according to the embodiment.
Description of reference numerals: 100-peak value holding type electromagnetic valve, 11-power supply end switching device, 12-grounding end switching device, 20-voltage dividing resistor, 31-power supply end freewheeling diode, 32-grounding end freewheeling diode, 40-energy storage element, 51-sampling module, 52-first comparison module, 60-logic element, 70-single chip microcomputer, 81-second comparison module and 82-desaturation detection module.
Detailed Description
To facilitate an understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings. Embodiments of the present application are set forth in the accompanying drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.
It will be understood that, as used herein, the terms "first," "second," and the like may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, a first resistance may be referred to as a second resistance, and similarly, a second resistance may be referred to as a first resistance, without departing from the scope of the present application. The first resistance and the second resistance are both resistances, but they are not the same resistance.
It is to be understood that "connection" in the following embodiments is to be understood as "electrical connection", "communication connection", and the like if the connected circuits, modules, units, and the like have communication of electrical signals or data with each other.
As used herein, the singular forms "a", "an" and "the" may include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises/comprising," "includes" or "including," etc., specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof. Also, as used in this specification, the term "and/or" includes any and all combinations of the associated listed items.
Referring to fig. 1, the present invention provides a control circuit for a peak hold solenoid valve, including: a power source terminal switching device 11, a ground terminal switching device 12, a voltage dividing resistor 20, a power source terminal freewheeling diode 31, a ground terminal freewheeling diode 32 and an energy storage element 40. A first terminal of the power source terminal switching device 11 is for connection to a power source, and a second terminal of the power source terminal switching device 11 is for connection to a power source terminal of the peak-hold-type solenoid valve 100. The power source terminal switching device 11 is used to control the on/off between the peak hold type solenoid valve 100 and the power source. A first terminal of the ground terminal switching device 12 is for connection to the ground terminal of the peak-hold type solenoid valve 100, and a second terminal of the ground terminal switching device 12 is for connection to ground. The ground terminal switching device 12 is used to control the on/off between the peak hold type solenoid valve 100 and the ground. The voltage dividing resistor 20 is connected in series between the second terminal of the power source terminal switching device 11 and the first terminal of the ground terminal switching device 12. The voltage dividing resistor 20 is used for dividing voltage with the peak hold type solenoid valve 100. The anode of the power-supply-side freewheeling diode 31 is used for connection to ground, and the cathode of the power-supply-side freewheeling diode 31 is connected to the second terminal of the power-supply-side switching device 11. The power source side freewheeling diode 31 is used to freewheel the peak-hold solenoid valve 100 when the power source side switching device 11 is off. The anode of the ground-side freewheeling diode 32 is connected to the first terminal of the ground-side switching device 12, and the cathode of the ground-side freewheeling diode 32 is used for connection to the power supply. The ground freewheeling diode 32 is used to freewheel the peak-hold solenoid valve 100 when the ground switching device 12 is off. One end of energy storage element 40 is for connection to a power source and the other end of energy storage element 40 is for connection to ground. The energy storage element 40 is used for storing electric energy when the voltage of the power supply is equal to the rated voltage and/or the freewheeling diode 31 at the power supply end and the freewheeling diode 32 at the ground end and releasing electric energy when the voltage of the power supply is less than the rated voltage.
Among them, an Electromagnetic valve (Electromagnetic valve) is an industrial equipment controlled by electromagnetism, and is used for controlling parameters such as a direction, a flow rate, and a speed of a fluid. An inductor is arranged in the peak holding type electromagnetic valve, two ends of the inductor are respectively a power supply end and a grounding end, the power supply end is connected with a power supply, and the grounding end is connected with the ground. When the power end of the inductor is connected with the grounding end, the current of the inductor gradually rises. When the current of the inductor rises above a threshold value, the solenoid valve is opened. When the power supply end and the grounding end of the inductor are disconnected, the current of the inductor gradually drops. When the current of the inductor drops below a threshold value, the solenoid valve closes.
The power supply terminal switching device 11 is a switching device connected to a power supply terminal of an inductor in the peak hold solenoid valve, and the ground terminal switching device 12 is a switching device connected to a ground terminal of an inductor in the peak hold solenoid valve. The switching device includes a first terminal, a second terminal, and a control terminal. When the control end of the switching device receives the first level signal, the first end of the switching device is communicated with the second end of the switching device. When the control terminal of the switching device receives the second level signal, the first terminal of the switching device and the second terminal of the switching device are disconnected. One of the first level signal and the second level signal is a high level signal, and the other of the first level signal and the second level signal is a low level signal.
The power supply end fly-wheel diode is a fly-wheel diode connected with the power supply end of an inductor in the peak holding type electromagnetic valve, and the ground end fly-wheel diode is a fly-wheel diode connected with the ground end of the inductor in the peak holding type electromagnetic valve.
In the control circuit of the peak hold type electromagnetic valve, the power supply end switching device is connected between the power supply and the power supply end of the peak hold type electromagnetic valve in series, and the on-off between the peak hold type electromagnetic valve and the power supply can be controlled. The grounding terminal switching device is connected between the grounding terminal of the peak holding type electromagnetic valve and the ground in series, and can control the on-off between the peak holding type electromagnetic valve and the ground. Therefore, only when the power terminal switching device and the ground terminal switching device are simultaneously closed, the peak hold type solenoid valve can be opened. Therefore, the safety risk caused by line faults can be reduced, and the reliability of the control circuit is improved. And analog-to-digital conversion (ADC) and additional control signals are not needed, the control signals are simple, and the method is suitable for the application scene of multi-electromagnetic valve driving of the diesel engine.
The voltage dividing resistor is connected in series between the power end switch device and the grounding end switch device, can divide voltage with the peak holding type electromagnetic valve when the power end switch device and the grounding end switch device are closed simultaneously, is matched with the peak holding type electromagnetic valve to realize the gentle change of voltage and current, and plays a certain role in protecting the peak holding type electromagnetic valve.
The positive pole of the power supply end fly-wheel diode is grounded, the negative pole of the power supply end fly-wheel diode is connected between the power supply end switch device and the peak holding type electromagnetic valve, the positive pole of the grounding end fly-wheel diode is connected between the peak holding type electromagnetic valve and the grounding end switch device, the negative pole of the grounding end fly-wheel diode is connected with the power supply, and the peak holding type electromagnetic valve, the divider resistor, the power supply end fly-wheel diode and the grounding end fly-wheel diode form a branch circuit connected between the power supply. Thus, when the power source terminal switching device and the ground terminal switching device are disconnected, the power source terminal freewheel diode and the ground terminal freewheel diode can freewheel the peak hold-type electromagnetic valve.
One end of the energy storage element is connected with a power supply, the other end of the energy storage element is grounded, and the energy storage element is connected with a branch consisting of the peak holding type electromagnetic valve, the divider resistor, the power supply end fly-wheel diode and the grounding end fly-wheel diode in parallel and can store electric energy when the voltage of the power supply is equal to the rated voltage and/or the power supply end fly-wheel diode and the grounding end fly-wheel diode fly-. The stored electric energy can be released when the voltage of the power supply is smaller than the rated voltage, so that when the voltage of the storage battery is lower due to the reasons of simultaneously driving a plurality of electromagnetic valves to be opened, long driving time of the electromagnetic valves, the engine to be started just, the engine to be started cold and the like, the energy storage element can release the electric energy to supplement the electric energy, the current rising speed of the electromagnetic valves is accelerated, the opening time of the electromagnetic valves is shortened, and the normal work of a diesel engine system is ensured. And the energy in the electromagnetic valve can be effectively utilized, the energy in the electromagnetic valve can flow to the energy storage element in time, and the excessive energy is prevented from being wasted on heating.
Illustratively, the power source is a battery.
Illustratively, the power source terminal switching device 11 and the ground terminal switching device 12 are MOS (Metal Oxide Semiconductor) transistors, such as NMOS transistors and PMOS transistors. At this time, the first terminal of the switching device is a drain, the second terminal of the switching device is a source, and the control terminal of the switching device is a gate.
Energy storage element 40 is illustratively a capacitor.
In one embodiment, as shown in fig. 1, the control circuit further comprises: an acquisition module 51, a first comparison module 52 and a logic element 60. The sampling modules 51 are connected to both ends of the voltage dividing resistor 20, respectively. The sampling module 51 is used for measuring the voltage of the voltage dividing resistor 20 to obtain the current of the peak-hold solenoid valve 100. The first comparison module 52 is connected to the sampling module 51. The first comparison module 52 is configured to compare the current of the peak-hold solenoid valve 100 with the opening/closing threshold current, and generate a current maintenance signal when the current of the peak-hold solenoid valve 100 is less than the opening/closing threshold current. The logic element 60 is connected to the first comparison block 52, the control terminal of the power source terminal switching device 11, and the control terminal of the ground terminal switching device 12, respectively. The logic element 60 is configured to generate a power source terminal switching control signal and a ground terminal switching control signal based on the current maintenance signal, and control the switching of the power source terminal switching device 11 and the switching of the ground terminal switching device 12.
In this embodiment, the sampling module 51 is connected to two ends of the voltage dividing resistor 20, respectively, and can measure the voltage of the voltage dividing resistor 20, so as to obtain the current of the peak-hold solenoid valve 100. The first comparison module 52 is connected to the sampling module 51, and is configured to compare the current of the peak-hold solenoid valve 100 with the opening/closing threshold current, and generate the current maintenance signal when the current of the peak-hold solenoid valve 100 is smaller than the opening/closing threshold current. The logic element 60 is respectively connected to the first comparing module 52, the control terminal of the power terminal switching device 11, and the control terminal of the ground terminal switching device 12, and can generate a power terminal on-off control signal and a ground terminal on-off control signal based on the current maintaining signal, so as to control the on-off of the power terminal switching device 11 and the on-off of the ground terminal switching device 12.
Specifically, the acquisition module 51 includes a voltage measurement device and a calculator, and the voltage measurement device is respectively connected to two ends of the voltage-dividing resistor 20 and is used for measuring the voltage of the voltage-dividing resistor 20. The calculator is connected to the voltage measuring device and the first comparing module 52, and is configured to calculate the current of the voltage dividing resistor 20 according to the voltage of the voltage dividing resistor 20 and the resistance of the voltage dividing resistor 20, so as to obtain the current of the peak-hold solenoid valve 100.
Illustratively, the acquisition module 51 may further include an amplifier connected in series between the calculator and the first comparison module 52.
Illustratively, the voltage measuring device is a voltmeter.
Specifically, the first comparing module 52 includes a first comparator including a non-inverting input terminal, an inverting input terminal, and an output terminal. The non-inverting input of the first comparator is used for inputting the switching threshold current, the inverting input of the first comparator is connected with the acquisition module 51, and the output of the first comparator is connected with the logic element 60. When the current of the peak-hold solenoid valve 100 is smaller than the switching threshold current, the input of the non-inverting input terminal of the first comparator is greater than or equal to the input of the inverting input terminal of the first comparator, and the output terminal of the first comparator outputs a high level signal, i.e., a current maintaining signal. When the current of the peak-hold solenoid valve 100 is greater than or equal to the switching threshold current, the input of the non-inverting input terminal of the first comparator is smaller than the input of the inverting input terminal of the first comparator, and the output terminal of the first comparator outputs a low-level signal, i.e., no signal is output.
Illustratively, the first comparator is a voltage comparator, and the non-inverting input terminal and the inverting input terminal input a voltage signal corresponding to the current signal.
Specifically, when the first comparing module 52 outputs the current maintaining signal, the logic component 60 sends the first level of on/off control signals to the control terminal of the power source terminal switching device 11 and the control terminal of the ground terminal switching device 12, respectively, to control the power source terminal switching device 11 and the ground terminal switching device 12 to be closed, i.e., the first terminal and the second terminal of the power source terminal switching device 11 are turned on, and the first terminal and the second terminal of the ground terminal switching device 12 are turned on. When the first comparing module 52 outputs no signal, the logic component 60 sends the second level on-off control signal to the control terminal of the power source terminal switching device 11 and the control terminal of the ground terminal switching device 12, respectively, to control the power source terminal switching device 11 and the ground terminal switching device 12 to be turned off, that is, the first terminal and the second terminal of the power source terminal switching device 11 are turned off, and the first terminal and the second terminal of the ground terminal switching device 12 are turned off.
Illustratively, the logic element 60 is a CPLD (Complex Programming logic device).
In one embodiment, as shown in fig. 1, the control circuit further comprises: a single chip microcomputer 70. The single chip microcomputer 70 is configured to generate a current enable signal according to an on-off command of the peak hold solenoid valve 100. The logic element 60 is further connected to the single chip 70, and is configured to perform a logical and operation on the current enable signal and the current sustain signal to generate a power end on/off control signal and a ground end on/off control signal.
In this embodiment, the control circuit further includes a single chip microcomputer 70, and the single chip microcomputer 70 may output a current enable signal when the peak-hold solenoid valve 100 is required to be opened, and may output no current enable signal when the peak-hold solenoid valve 100 is required to be closed. The logic element 60 is connected to the single chip microcomputer 70, and can generate a power end on/off control signal and a ground end on/off control signal by comprehensively considering the current enable signal and the current hold signal, and control the power end switching device 11 and the ground end switching device 12.
Specifically, when the peak-hold solenoid valve 100 needs to be opened, the single chip microcomputer 70 outputs a current enable signal, and the current maintain signal and the current enable signal perform a logical and operation, that is, a power end switching control signal and a ground end switching control signal are generated according to the current maintain signal, so as to control the power end switching device 11 and the ground end switching device 12, thereby opening the peak-hold solenoid valve 100. When the peak-hold solenoid valve 100 needs to be closed, the single chip microcomputer 70 does not output the current enabling signal, the current maintaining signal and the current enabling signal perform logical and operation, and the generated power end switching control signal and the ground end switching control signal only control the power end switching device 11 and the ground end switching device 12 to be disconnected, so that the peak-hold solenoid valve 100 is closed.
Illustratively, the single chip microcomputer 70 includes a GTM (general purpose timer module), and the single chip microcomputer 70 generates a current enable signal through the GTM.
Logic element 60 comprises a first and gate comprising two inputs and an output. One input end of the first and gate is connected with the single chip microcomputer 70 and used for inputting a current enable signal; the other input end of the first and gate is connected with the first comparing module 52 and is used for inputting a current maintaining signal; the output end of the first and gate is connected to the control end of the power source terminal switching device 11 and the control end of the ground terminal switching device 12, respectively, and outputs a power source terminal on-off control signal and a ground terminal on-off control signal.
In one embodiment, as shown in fig. 1, the one-chip microcomputer 70 is further configured to generate an opening/closing threshold current switching signal according to a switching instruction of the opening/closing threshold current. The first comparing module 52 is further connected to the single chip microcomputer 70, and is configured to switch the switching threshold current compared with the current of the peak hold solenoid valve 100 according to the switching threshold current switching signal.
In this embodiment, the single chip microcomputer 70 generates an opening/closing threshold current switching signal according to the switching instruction of the opening/closing threshold current, and the first comparing module 52 may switch the opening/closing threshold current compared with the current of the peak-hold solenoid valve 100 according to the opening/closing threshold current switching signal, so as to implement the second-order holding current required for driving the peak-hold solenoid valve.
Specifically, when the switching threshold current switching signal is a level signal, the first comparing module 52 adopts a switching threshold current; when the switching threshold current switching signal is another level signal, the first comparing module 52 adopts another switching threshold current. The two level signals are respectively a high level signal and a low level signal, and correspond to signal output and no signal output.
The first comparison module 52 further includes an electromagnetic relay including a normally open contact, a normally closed contact, a movable contact, and a control terminal. The control end of the electromagnetic relay inputs the switching threshold current switching signal, the movable contact of the electromagnetic relay is connected with the first comparison module 52, and the normally open contact and the normally closed contact of the electromagnetic relay respectively input two switching threshold currents. When no signal is input into the control end of the electromagnetic relay, the movable contact is connected with the normally closed contact; when a signal is input into the control end of the electromagnetic relay, the movable contact is connected with the normally open contact, so that switching of the switching threshold current input into the first comparison module 52 is realized.
Illustratively, the one-chip microcomputer 70 includes a GTM through which the one-chip microcomputer 70 generates an opening and closing threshold current switching signal.
In one embodiment, as shown in fig. 1, the voltage dividing resistor 20 is connected in series between the ground terminal of the peak-hold solenoid valve 100 and the first terminal of the ground terminal switching device 12.
Correspondingly, the control circuit further comprises: a second comparison module 81 and a desaturation detection module 82. The second comparing module 81 is connected to the sampling module 51. The second comparing module 81 is configured to compare the current of the peak hold solenoid valve 100 with a short-circuit threshold current, and generate a ground end overcurrent indication signal when the current of the peak hold solenoid valve 100 is greater than the short-circuit threshold current. The desaturation detection module 82 is connected to the power source side switching device 11. The desaturation detection module 82 is configured to detect a voltage between the first terminal and the second terminal of the power source side switching device 11, and generate a power source side overcurrent indication signal when the voltage between the first terminal and the second terminal of the power source side switching device 11 is greater than a desaturation threshold voltage. The logic element 60 is further connected to the second comparing module 81 and the desaturation detecting module 82, and is configured to determine that the branch of the peak hold type solenoid valve 100 is shorted when at least one of the ground terminal indication signal and the power terminal indication signal is received, and control the power terminal switching device 11 and the ground terminal switching device 12 to be disconnected.
In this embodiment, the voltage dividing resistor 20 is connected in series between the ground terminal of the peak-hold solenoid valve 100 and the first terminal of the ground terminal switching device 12, and the ground terminal of the peak-hold solenoid valve 100 can be detected by the voltage dividing resistor 20, so that the sampling is not affected by the open/close states of the power terminal switching device 11 and the ground terminal switching device 12. Specifically, the second comparing module 81 is connected to the sampling module 51, and can compare the current of the peak-hold solenoid valve 100 with the short-circuit threshold current, and generate the ground end overcurrent indication signal when the current of the peak-hold solenoid valve 100 is greater than the short-circuit threshold current. In addition, the desaturation detection module 82 is connected to the power source terminal switching device 11, and is capable of detecting a voltage between the first terminal and the second terminal of the power source terminal switching device 11, and generating a power source terminal overcurrent indication signal when the voltage between the first terminal and the second terminal of the power source terminal switching device 11 is greater than a desaturation threshold voltage, so as to detect the power source terminal of the peak hold solenoid valve 100. In this way, when the logic component 60 receives at least one of the ground terminal indication signal and the power terminal indication signal, it may determine that the branch where the peak hold solenoid valve 100 is located is short-circuited, and control the power terminal switching device 11 and the ground terminal switching device 12 to be disconnected, so as to implement timely protection of the peak hold solenoid valve 100.
Specifically, the second comparing module 81 includes a second comparator including a non-inverting input terminal, an inverting input terminal, and an output terminal. The non-inverting input of the second comparator is connected to the acquisition module 51, the inverting input of the second comparator is used for inputting the short-circuit threshold current, and the output of the second comparator is connected to the logic element 60. When the current of the peak-hold solenoid valve 100 is greater than or equal to the short-circuit threshold current, the input of the non-inverting input terminal of the second comparator is greater than or equal to the input of the inverting input terminal of the second comparator, and the output terminal of the second comparator outputs a high-level signal, i.e., a ground terminal overcurrent indicating signal. When the current of the peak-hold solenoid valve 100 is smaller than the short-circuit threshold current, the input of the non-inverting input terminal of the second comparator is smaller than the input of the inverting input terminal of the second comparator, and the output terminal of the second comparator outputs a low-level signal, that is, an ungrounded terminal overcurrent indication signal.
Illustratively, the second comparator is a voltage comparator, and the non-inverting input terminal and the inverting input terminal input voltage signals corresponding to the current signals.
Specifically, the desaturation detection module 82 may include a voltage measurement device connected to the first terminal and the second terminal of the power source side switching device 11, respectively, for measuring the voltage of the power source side switching device 11, and a comparator. The non-inverting input of the comparator is connected to the voltage measuring device, the inverting input of the comparator is used for inputting the desaturation threshold voltage, and the output of the comparator is connected to the logic element 60. When the voltage of the power source terminal switching device 11 is greater than or equal to the desaturation threshold voltage, the input of the non-inverting input terminal of the comparator is greater than or equal to the input of the inverting input terminal of the comparator, and the output terminal of the comparator outputs a high level signal, i.e., a power source terminal overcurrent indication signal. When the voltage of the power source terminal switching device 11 is less than the desaturation threshold voltage, the input of the non-inverting input terminal of the comparator is less than the input of the inverting input terminal of the comparator, and the output terminal of the comparator outputs a low level signal, that is, no power source terminal overcurrent indication signal is output.
Specifically, the logic element 60 includes a first or gate including two inputs and one output. One input end of the first or gate is connected with the second comparison module 81 and is used for inputting a grounding end overcurrent indication signal; the other input terminal of the first or gate is connected to the desaturation detection module 82, and is configured to input a power source end overcurrent indication signal. The first or gate performs logical or calculation on the ground terminal indication signal and the power terminal indication signal, an output terminal of the first or gate is respectively connected to the control terminal of the power terminal switching device 11 and the control terminal of the ground terminal switching device 12, and determines that the branch where the peak hold type solenoid valve 100 is located is short-circuited when at least one of the ground terminal indication signal and the power terminal indication signal is received, and controls disconnection of the power terminal switching device 11 and the ground terminal switching device 12.
In one embodiment, as shown in fig. 1, the desaturation detection module 82 is a driver chip connected in series between the control terminal of the power source side switching device 11 and the logic element 60.
In this embodiment, the desaturation detection module 82 employs a driving chip connected in series between the control terminal of the power source terminal switching device 11 and the logic element 60, and utilizes the self-contained function of the driving chip, so that when the driving chip is used to provide the required driving voltage for the power source terminal switching device 11, the driving chip can be used to perform desaturation detection on the power source terminal switching device 11, thereby improving the integration level of the control circuit.
Specifically, the driving chip is an integrated chip with MOS tube desaturation detection and protection functions. The current of the MOS transistor in the power end switching device 11 rises rapidly when the branch is short-circuited, and when the current is large to a certain extent, a desaturation phenomenon occurs, so that the voltage between the drain and the source rises rapidly. The integrated chip can detect the desaturation phenomenon, control the disconnection of the MOS tube in the power supply end switching device 11, and simultaneously output a power supply end overcurrent indicating signal to the logic element 60.
In practical applications, a driving chip may be connected in series between the control terminal of the ground switching device 12 and the logic element 60, and the driving chip is used to provide the ground switching device 12 with the required driving voltage.
In one embodiment, the logic component 60 is further configured to determine the short circuit type based on the current maintenance signal, the ground terminal overcurrent indication signal, and the power terminal overcurrent indication signal.
In this embodiment, the short circuit type can be determined by comprehensively considering the current maintaining signal, the ground end overcurrent indicating signal and the power end overcurrent indicating signal, which is beneficial to removing faults.
Specifically, when neither the power source terminal nor the ground terminal of the peak hold type solenoid valve is short-circuited, a current passes through the power source terminal switching device 11, a current passes through the peak hold type solenoid valve 100, the voltage dividing resistor 20, and the ground terminal switching device 12, there is a current hold signal, and there is no power terminal overcurrent indication signal and no ground terminal overcurrent indication signal.
When the power end of the peak hold type electromagnetic valve is short-circuited to the power supply, the power end of the peak hold type electromagnetic valve 100 is connected with the power supply, the current does not pass through the power end switching device 11, and no power end overcurrent indicating signal exists; the current passes through the peak-hold solenoid valve 100, the voltage dividing resistor 20, and the ground terminal switching device 12, and the peak-hold solenoid valve 100 may be controlled by the ground terminal switching device 12 with a current maintaining signal and an ungrounded terminal overcurrent indicating signal. The peak hold solenoid valve 100 can freewheel through the ground freewheeling diode 32. In this short circuit type, the control circuit can continue to operate.
When the power end of the peak hold type solenoid valve is short-circuited to the ground, the power end of the peak hold type solenoid valve 100 is connected to the ground, the current does not pass through the peak hold type solenoid valve 100, the divider resistor 20 and the ground end switching device 12, and a current maintaining signal and a ground end overcurrent indicating signal do not exist; the current passes only through the power source terminal switching device 11, and there is a power source terminal overcurrent indicating signal.
When the ground terminal of the peak hold type electromagnetic valve is short-circuited to the power supply, the ground terminal of the peak hold type electromagnetic valve 100 is connected to the power supply, the current does not pass through the power supply terminal switching device 11 and the peak hold type electromagnetic valve 100, and no power supply terminal overcurrent indication signal exists; the current only passes through the voltage-dividing resistor 20 and the ground terminal switching device 12, and there are a current maintaining signal and a ground terminal overcurrent indicating signal.
When the ground terminal of the peak hold solenoid valve is short-circuited to the ground, the ground terminal of the peak hold solenoid valve 100 is connected to the ground, the current does not pass through the voltage dividing resistor 20 and the ground terminal switching device 12, and no current maintaining signal or a ground terminal overcurrent indicating signal exists; the current only passes through the power supply end switching device 11 and the peak holding type electromagnetic valve 100, no power supply end overcurrent indicating signal exists in the initial stage, but the internal resistance of the peak holding type electromagnetic valve is small, and the power supply end overcurrent indicating signal can be generated in the subsequent stage.
When the power supply terminal and the ground terminal of the peak hold solenoid valve are short-circuited, the power supply terminal and the ground terminal of the peak hold solenoid valve 100 are connected, the current does not pass through the peak hold solenoid valve 100, the current only passes through the power supply terminal switching device 11, the voltage-dividing resistor 20 and the ground terminal switching device 12, and the power supply terminal overcurrent indication signal, the current holding signal and the ground terminal overcurrent indication signal all have.
In summary, the logic element 60 can determine the short circuit type using the following table one:
table-electromagnetic valve short-circuit fault truth table
Figure BDA0002948339480000141
As can be seen from the table i, the power end overcurrent indication signal, the ground end overcurrent indication signal, and the current holding signal are the same when the power end of the peak hold solenoid valve is shorted to ground, as when the ground end of the peak hold solenoid valve is shorted to ground. Further differentiation can be made at this time in the following manner:
in one embodiment, as shown in FIG. 1, the single chip 70 is further configured to generate a clock signal. The logic component 60 is further configured to determine a time duration before the generation of the ground terminal over-current indication signal according to the clock signal, and to distinguish the short circuit type according to the time duration before the generation of the ground terminal over-current indication signal.
When the power terminal of the peak hold type solenoid valve is short-circuited to the ground, the current passes through only the power terminal switching device 11, whereas when the ground terminal of the peak hold type solenoid valve is short-circuited to the ground, the current passes through both the power terminal switching device 11 and the peak hold type solenoid valve 100, so that the generation time of the power terminal overcurrent indication signal when the power terminal of the peak hold type solenoid valve is short-circuited to the ground is much earlier than the generation time when the ground terminal of the peak hold type solenoid valve is short-circuited to the ground. In this embodiment, the single chip microcomputer 70 generates a clock signal, and the logic component 60 can determine the time length before the generation of the ground end overcurrent indication signal according to the clock signal, and further distinguish the short circuit type according to the time length before the generation of the ground end overcurrent indication signal.
Specifically, the logic element 60 may average the generation time of the power supply terminal overcurrent indication signal when the power supply terminal of the peak hold type solenoid valve is short-circuited to the ground and the generation time of the power supply terminal overcurrent indication signal when the ground terminal of the peak hold type solenoid valve is short-circuited to the ground, and take the average as the time threshold. When the generation time of the power end overcurrent indicating signal is less than a time threshold, the short circuit type is a power end-to-ground short circuit of the peak holding type electromagnetic valve; when the generation time of the source end overcurrent indicating signal is larger than or equal to a time threshold value, the short circuit type is that the ground end of the peak holding type electromagnetic valve is short-circuited to the ground.
Illustratively, the single chip microcomputer 70 includes a GTM through which the single chip microcomputer 70 generates a clock signal.
In one embodiment, the logic element 60 is also configured to determine that the branch in which the peak-hold solenoid valve 100 is located is open when the current enable signal is received and the current maintenance signal is not received.
When the logic element 60 does not receive the current enable signal, both the power terminal switching device 11 and the ground terminal switching device 12 are turned off, and it is not determined that the branch in which the peak-hold type solenoid valve 100 is located is open although there is no current hold signal. In this embodiment, the logic element 60 comprehensively considers the current enable signal and the current maintaining signal, and determines that the branch where the peak-hold solenoid valve 100 is located is open when the current enable signal is received and the current maintaining signal is not received, so as to ensure the accuracy of the determination.
Specifically, the logic element 60 includes a first not gate including one input terminal and one output terminal, and a second and gate including two input terminals and one output terminal. The input end of the first NOT gate is used for inputting a current maintaining signal, the output end of the first NOT gate is connected with one input end of the second AND gate, the other input end of the second AND gate is used for inputting a current enabling signal, and the output end of the second AND gate is used for outputting a breaking indicating signal.
In practical applications, the logic element 60 includes two D flip-flops, one of which latches the current enable signal, and the other of which latches and acquires the current maintaining signal when the current enable signal is high. If the current maintaining signal is latched, it indicates that the branch in which the peak-hold solenoid valve 100 is located is not open. If the current enable signal is latched, it is determined that the branch in which the peak-hold solenoid valve 100 is located is open-circuited when the current sustain signal is not latched. A selector can be added, the selection is carried out by adopting the latching result of the current enable signal, and when the current enable signal is latched, the latching result of the current maintaining signal determines whether the branch where the peak holding type electromagnetic valve 100 is positioned is broken; when the current enable signal is not latched, the latching result of the current maintaining signal cannot determine whether the branch where the peak-hold solenoid valve 100 is located is open-circuited, i.e., the determination result is invalid.
In one embodiment, the logic element 60 is also configured to generate and latch an indicator signal when the branch in which the peak-hold solenoid valve 100 is located is shorted or open.
In this embodiment, the logic element 60 generates and latches the indication signal when the branch in which the peak-hold solenoid valve 100 is located is short-circuited or open-circuited, and can maintain the state after the power end switching device 11 and the ground end switching device 12 are controlled to be disconnected, so as to prevent the power end switching device 11 and the ground end switching device 12 from being controlled to be connected in the case of a fault.
Specifically, the logic element 60 further includes two D flip-flops, one of which generates and latches a short-circuit indication signal when the branch in which the peak-hold solenoid valve 100 is located is short-circuited, and the other of which generates and latches a disconnection indication signal when the branch in which the peak-hold solenoid valve 100 is located is disconnected.
In addition, the logic element 60 can send the short circuit indication signal and the open circuit indication signal to the single chip microcomputer 70, and the control software only needs to read the fault diagnosis state before driving every time and does not need to read in real time, so that the fault diagnosis logic of the control software is simplified.
In practical applications, the single chip microcomputer 70 is provided with an input/output (I/O) module, and can output a zero clearing signal to the logic element 60, where the zero clearing signal is used to clear latch signals of all D flip-flops, and after the software finishes reading short-circuit and open-circuit fault indications, the D flip-flops can be reset for subsequent fault diagnosis.
In the embodiment, the fault diagnosis does not need the participation of control software, the CPLD obtains the short-circuit fault and the open-circuit fault of the electromagnetic valve completely, and only a simple comparison circuit needs to be added outside, so that the fault diagnosis difficulty of the control software is greatly reduced, and the reliability of the fault diagnosis is improved. And the response time is only a few nanoseconds, which is far faster than microsecond-level response time of a hardware and software fault diagnosis scheme, and is beneficial to the protection of a solenoid valve coil and a driving circuit.
Referring to fig. 2, the control process of the peak hold solenoid valve includes four stages of pre-driving (T0), first-order holding current (T1, T2), second-order holding current (T3, T4) and driving off (T5). The actual operation of each stage is described separately below.
Pre-drive (T0) phase: all signals are in a low level invalid state, and no current flows in the solenoid valve. There is no specific time length in this stage, which generally refers to a period of time after the last operation of the solenoid valve is finished or before the solenoid valve is ready to be driven next time from the operation of the solenoid valve is not started. The T0 stage is mainly used for reading the fault diagnosis state of the last solenoid valve during operation by software, namely reading the short circuit indication state and the open circuit indication state through the I/O port of the single chip microcomputer. After reading is completed, the output state of the trigger is reset through the zero clearing signal. The clear signal outputs a low level for clearing at stage T0, and then goes high until the next clearing. The T0 phase ensures consistency of the fault diagnosis state before each drive.
First-order holding current (T1, T2) phase: the current enable signal is at a high level, the current sustain signal is at a high level, both the power source terminal switching control signal and the ground terminal switching control signal are at a high level, the power source terminal switching device 11 and the ground terminal switching device 12 are turned on, the peak hold solenoid valve 100 forms a loop with the power source and the ground, the current of the peak hold solenoid valve 100 rises until it is greater than the switching threshold current, and the stage T1 ends.
When the current of the peak-hold solenoid valve 100 rises to be greater than the on-off threshold current, the current maintaining signal becomes low level, the power source terminal on-off control signal and the ground terminal on-off control signal are both low level, the power source terminal switching device 11 and the ground terminal switching device 12 are turned off, the current of the peak-hold solenoid valve 100 continues to flow from the power source terminal freewheeling diode 31 and the ground terminal freewheeling diode 32, the energy storage element 40 is charged, and the current of the peak-hold solenoid valve 100 falls.
When the current of the peak hold solenoid valve 100 decreases to be smaller than the on/off threshold current, the current hold signal becomes high level, both the power source terminal on/off control signal and the ground terminal on/off control signal are high level, the power source terminal switching device 11 and the ground terminal switching device 12 are turned on, the peak hold solenoid valve 100 forms a loop with the power source and the ground, and the current of the peak hold solenoid valve 100 rises again.
This is repeated until the switching threshold current switching signal changes level, e.g., changes from low level to high level, at which point the stage T2 ends.
Second-order holding current (T3, T4) phase: when the switching threshold current is switched, the current of the peak-hold solenoid valve 100 is maintained at a value near the switching threshold current before switching. Taking the example that the switching threshold current before switching is higher than the switching threshold current after switching, at this time, the current maintaining signal becomes low level, the power source terminal switching device 11 and the ground terminal switching device 12 are turned off, the current of the peak hold type solenoid valve 100 continues to flow from the power source terminal freewheeling diode 31 and the ground terminal freewheeling diode 32 to charge the energy storage element 40, the current of the peak hold type solenoid valve 100 decreases until it is smaller than the switching threshold current after switching, and at this time, the stage T3 ends.
When the current of the peak hold solenoid valve 100 decreases to be smaller than the switched on/off threshold current, the current hold signal becomes high level, both the power source terminal on/off control signal and the ground terminal on/off control signal are high level, the power source terminal switching device 11 and the ground terminal switching device 12 are turned on, the peak hold solenoid valve 100 forms a loop with the power source and the ground, and the current of the peak hold solenoid valve 100 increases.
When the current of the peak hold solenoid valve 100 rises to be larger than the switched on/off threshold current, the current hold signal becomes low level, the power source terminal on/off control signal and the ground terminal on/off control signal are both low level, the power source terminal switching device 11 and the ground terminal switching device 12 are turned off, the current of the peak hold solenoid valve 100 continues to flow from the power source terminal freewheeling diode 31 and the ground terminal freewheeling diode 32, the energy storage element 40 is charged, and the current of the peak hold solenoid valve 100 decreases.
This is repeated until the current enable signal goes low, at which point the T4 phase ends.
Drive off (T5) phase: when the current enable signal is switched from the high-level active state to the low-level inactive state, that is, this driving is finished, the power-side switching control signal and the ground-side switching control signal are both at a low level, the power-side switching device 11 and the ground-side switching device 12 are turned off, the current of the peak-hold solenoid valve 100 continues to flow from the power-side freewheeling diode 31 and the ground-side freewheeling diode 32 to charge the energy storage element 40, and the current of the peak-hold solenoid valve 100 decreases to 0.
In practical application, a high level can be used as an active level, and a low level can be used as an inactive level; it is also possible to use a low level as the active level and a high level as the inactive level. Taking the power end overcurrent indicating signal and the grounding end overcurrent indicating signal as examples, the low level is taken as the effective level, and the fault diagnosis process is as follows:
as shown in fig. 2, during the short-circuit fault diagnosis, the power end overcurrent indication signal and the ground end overcurrent indication signal are respectively inverted and then subjected to a logical and operation as the input of the D flip-flop 1, and after the output of the D flip-flop 1 is inverted, the D flip-flop is respectively subjected to a logical and operation with the power end on-off control signal and the ground end on-off control signal, so that the power end switching device and the ground end switching device can be controlled to be disconnected to protect the solenoid valve during the short-circuit fault.
As shown in fig. 2, when the current enable signal is active high in the open circuit fault diagnosis, the D flip-flop 2 captures the level and latches it as a high output. After the current of the solenoid valve rises to a first-order maintaining current threshold value in the window period of T1, the current maintaining signal is high level and the D trigger 3 captures and latches. The latch output of the D trigger 2 is used as a selection switch of the alternative selector, and when the selection switch of the alternative selector is 0, the output is always at a high level; when the selection switch of the alternative selector is 1, the latch signal of the D flip-flop 3 is output. That is, only when the D flip-flop 2 latches the current enable signal, the D flip-flop outputs a high level without a break, otherwise, there is a break, and thus, the D flip-flop 3 is directly used as an output to avoid misdiagnosis under the condition of no driving.
The short circuit type has a phenomenon in which a current enable signal is present but a sustain current signal is not detected, which is the same as the open circuit fault phenomenon. However, the short-circuit type can be determined according to the over-current indication signal of the power supply end and the over-current indication signal of the grounding end, in addition, the damage of the short-circuit fault to the system is larger than that of the open-circuit fault, the control software can preferentially judge the short-circuit fault when judging the fault, and the open-circuit fault can be identified on the premise of no short-circuit fault, so that misdiagnosis cannot exist.
It is to be understood that the logic element may take other forms, not limited to the form already mentioned in the above embodiments, as long as it can achieve the functions of completing the drive control and the fault diagnosis.
Further, although D flip-flops are used in the embodiments described above, JK flip-flops may alternatively be used.
The circuit can be applied to peak hold type electromagnetic valves of first-order maintaining current drive, second-order maintaining current drive and the like. The peak holding type electromagnetic valve drive generally adopts a first-order or two-order maintaining current waveform, firstly, a driving voltage is applied to a solenoid valve coil, the current of the solenoid valve coil is increased to a peak current, then, a modulation current is applied according to whether the peak current needs to be maintained, and if the peak current does not need to be maintained, only a single peak is added with a first-order maintaining current; the peak value holding current is needed, two-stage holding current is provided, the circuit can well support the current waveform, and only the pulse width of the current threshold switching signal needs to be properly adjusted.
In the description herein, references to the description of "some embodiments," "other embodiments," "desired embodiments," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, a schematic description of the above terminology may not necessarily refer to the same embodiment or example.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (10)

1. A control circuit for a peak-hold solenoid valve, comprising:
a power supply end switching device (11), a first end of which is used for being connected with a power supply, and a second end of which is used for being connected with a power supply end of a peak holding type electromagnetic valve (100) and controlling the on-off between the peak holding type electromagnetic valve (100) and the power supply;
a ground terminal switching device (12), a first terminal of which is used for being connected with a ground terminal of the peak holding type electromagnetic valve (100), and a second terminal of which is used for being connected with the ground and controlling the on-off between the peak holding type electromagnetic valve (100) and the ground;
a voltage dividing resistor (20) connected in series between the second terminal of the power terminal switching device (11) and the first terminal of the ground terminal switching device (12) for dividing voltage with the peak hold solenoid valve (100);
a power source side freewheeling diode (31) having an anode connected to the ground and a cathode connected to the second terminal of the power source side switching device (11) for freewheeling to the peak-hold solenoid valve (100) when the power source side switching device (11) is turned off;
a ground-side freewheeling diode (32) having a positive terminal connected to the first terminal of the ground-side switching device (12) and a negative terminal for connection to the power supply, for freewheeling to the peak-hold solenoid valve (100) when the ground-side switching device (12) is turned off;
and the energy storage element (40) is used for being connected with the power supply at one end and being connected with the ground at the other end, storing the electric energy when the voltage of the power supply is equal to the rated voltage and/or the power supply end freewheeling diode (31) and the ground end freewheeling diode (32) freewheel, and releasing the electric energy when the voltage of the power supply is less than the rated voltage.
2. The control circuit of claim 1, further comprising:
the sampling module (51) is respectively connected with two ends of the voltage dividing resistor (20) and is used for measuring the voltage of the voltage dividing resistor (20) to obtain the current of the peak holding type electromagnetic valve (100);
a first comparison module (52) connected to the sampling module (51) for comparing the current of the peak-hold solenoid valve (100) with an on-off threshold current and generating a current maintenance signal when the current of the peak-hold solenoid valve (100) is less than the on-off threshold current;
and a logic element (60) respectively connected to the first comparison module (52), the control terminal of the power end switch device (11) and the control terminal of the ground end switch device (12), and configured to generate a power end on-off control signal and a ground end on-off control signal based on the current maintaining signal, and control the on-off of the power end switch device (11) and the on-off of the ground end switch device (12).
3. The control circuit of claim 2, further comprising:
the single chip microcomputer (70) is used for generating a current enabling signal according to the on-off instruction of the peak holding type electromagnetic valve (100);
the logic element (60) is further connected to the single chip microcomputer (70) and configured to perform a logical and operation on the current enable signal and the current maintaining signal to generate the power end switching control signal and the ground end switching control signal.
4. The control circuit according to claim 3, wherein the single chip microcomputer (70) is further configured to generate a switching threshold current switching signal according to the switching instruction of the switching threshold current;
the first comparison module (52) is also connected with the singlechip (70) and is used for switching the switching threshold current compared with the current of the peak holding type electromagnetic valve (100) according to the switching threshold current switching signal.
5. The control circuit according to claim 3 or 4, characterized in that the voltage-dividing resistor (20) is connected in series between a ground terminal of the peak-hold solenoid valve (100) and a first terminal of the ground terminal switching device (12); the control circuit further includes:
the second comparison module (81) is connected with the sampling module (51) and used for comparing the current of the peak-hold type electromagnetic valve (100) with a short-circuit threshold current and generating a grounding end overcurrent indication signal when the current of the peak-hold type electromagnetic valve (100) is larger than the short-circuit threshold current;
a desaturation detection module (82) connected to the power source terminal switching device (11) for detecting a voltage between the first terminal and the second terminal of the power source terminal switching device (11) and generating a power source terminal over-current indication signal when the voltage between the first terminal and the second terminal of the power source terminal switching device (11) is greater than a desaturation threshold voltage;
the logic element (60) is further connected to the second comparing module (81) and the desaturation detecting module (82), and is configured to determine that a short circuit occurs in a branch where the peak-hold solenoid valve (100) is located when at least one of the ground terminal indication signal and the power terminal indication signal is received, and control the power terminal switching device (11) and the ground terminal switching device (12) to be turned off.
6. The control circuit according to claim 5, wherein the desaturation detection module (82) is a driver chip connected in series between the control terminal of the power source side switching device (11) and the logic element (60).
7. The control circuit of claim 5, wherein the logic element (60) is further configured to determine a short circuit type based on the current maintenance signal, the ground end over-current indication signal, and the power end over-current indication signal.
8. The control circuit of claim 7, wherein the single-chip (70) is further configured to generate a clock signal;
the logic element (60) is further configured to determine a duration before the generation of the ground end over-current indication signal according to the clock signal, and to distinguish a short circuit type according to the duration before the generation of the ground end over-current indication signal.
9. The control circuit according to claim 5, wherein the logic element (60) is further configured to determine that the branch in which the peak-and-hold solenoid (100) is located is open-circuited when the current enable signal is received and the current maintenance signal is not received.
10. The control circuit according to claim 9, characterized in that the logic element (60) is also adapted to generate and latch an indication signal when the branch in which the peak-hold solenoid (100) is located is short-circuited or open-circuited.
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CN114704411A (en) * 2022-04-14 2022-07-05 一汽解放汽车有限公司 Electromagnetic valve drive control method
CN115001276A (en) * 2022-07-18 2022-09-02 南京工业大学 Peak-hold driving circuit with fault diagnosis protection function and unmanned aerial vehicle engine applying same

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CN104660225A (en) * 2015-01-19 2015-05-27 中国船舶重工集团公司第七一九研究所 Nuclear pulse peak value holding circuit
CN107580663A (en) * 2015-03-18 2018-01-12 自动开关公司 Ensure the release of the solenoid valve by peak holding driver control
CN112368499A (en) * 2018-07-03 2021-02-12 日立汽车系统株式会社 Solenoid valve driving device

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JP2006152987A (en) * 2004-12-01 2006-06-15 Denso Corp Solenoid valve drive mechanism
CN1967035A (en) * 2006-10-19 2007-05-23 上海凌同电子科技有限公司 Double-peak-voltage holding high-speed solenoid valve drive circuit
CN104214395A (en) * 2014-09-09 2014-12-17 南京普东兴生物科技有限公司 Multipurpose driving circuit for optical gate or biochemical reagent accurate sampling electromagnetic valve
CN104373662A (en) * 2014-12-03 2015-02-25 中国第一汽车股份有限公司无锡油泵油嘴研究所 Method and device for controlling electromagnetic valves
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114704411A (en) * 2022-04-14 2022-07-05 一汽解放汽车有限公司 Electromagnetic valve drive control method
CN115001276A (en) * 2022-07-18 2022-09-02 南京工业大学 Peak-hold driving circuit with fault diagnosis protection function and unmanned aerial vehicle engine applying same
CN115001276B (en) * 2022-07-18 2022-10-25 南京工业大学 Peak-hold driving circuit with fault diagnosis protection function and unmanned aerial vehicle engine applying peak-hold driving circuit

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