Self-inductance current release control circuit and method and electromagnetic valve equipment

Abstract

The invention provides a self-inductance current release control circuit and method and electromagnetic valve equipment, the self-inductance current release control circuit comprises an electromagnetic valve driving module and a self-inductance current release module, and the electromagnetic valve driving module is connected with the self-inductance current release module; the electromagnetic valve driving module comprises a first field effect transistor, an electromagnetic valve coil and a second field effect transistor; the self-inductance current release module comprises a third field effect transistor; the source electrode of the third field effect transistor is connected with the drain electrode of the second field effect transistor, the drain electrode of the third field effect transistor is connected with the source electrode of the first field effect transistor, and the source electrode of the second field effect transistor is grounded; wherein the third field effect transistor is switched on when the source voltage reaches a self-inductance current release threshold, so that the self-inductance current generated by the electromagnetic valve coil is released in the follow current loop. According to the embodiment of the invention, the self-inductance current release module is connected with the electromagnetic valve driving module, so that the self-inductance current generated by the electromagnetic valve coil is released through the follow current loop, the heating of a device is reduced, and the control can be realized through high-frequency PWM (Pulse-Width Modulation).

Description

Technical Field

[0001] The invention belongs to the field of circuit control, and in particular relates to a self-inductive current release control circuit, method and solenoid valve equipment. Background Art

[0002] In the underlying execution system of the car, it is necessary to control the brake system, motor, solenoid valve and other execution components to ensure the body stability, driving safety and other performance of the car. To achieve the above performance, the solenoid valve is required to be able to close quickly and respond quickly.

[0003] In the current solenoid valve switch control circuit scheme, the high voltage generated by the self-induced electromotive force of the solenoid valve coil is often used to turn on the low-side MOS tube to release the self-induced current generated by the solenoid valve coil at the moment of power failure. However, this method will cause the drain of the low-side MOS tube to generate high voltage, which is enough to have an adverse effect on the life of the MOS tube. In addition, due to the high voltage caused by the instantaneous rapid release of current, the circuit components will have serious heat generation and are prone to damage, and high-frequency PWM control cannot be used.

[0004] Therefore, there is an urgent need for a solution that can quickly release the self-inductance current and achieve high-frequency PWM control. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a self-inductive current release control circuit, method and solenoid valve device.

[0006] On the one hand, the present invention provides a self-inductive current release control circuit, the self-inductive current release control circuit includes a solenoid valve drive module and a self-inductive current release module, the solenoid valve drive module is connected to the self-inductive current release module;

[0007] The solenoid valve driving module includes a first field effect tube, a solenoid valve coil and a second field effect tube; the self-inductance current release module includes a third field effect tube; the source of the third field effect tube is connected to the drain of the second field effect tube, the drain of the third field effect tube is connected to the source of the first field effect tube, and the source of the second field effect tube is grounded;

[0008] Among them, the third field effect tube is turned on when the source voltage reaches the self-inductance current release threshold, so that the self-inductance current generated by the solenoid valve coil is released in the freewheeling circuit, and the freewheeling circuit is a circuit formed between the solenoid valve coil and the third field effect tube.

[0009] In some possible implementations, the self-inductive current release control circuit further includes a self-inductive current release threshold adjustment module for adjusting the self-inductive current release threshold;

[0010] The self-inductive current release threshold adjustment module is connected to the solenoid valve driving module, and is connected to the self-inductive current release module through the gate of the third field effect transistor;

[0011] Wherein, the self-inductance current release threshold adjustment module adjusts the self-inductance current release threshold.

[0012] In some possible implementations, the self-inductance current release threshold adjustment module includes a voltage follower, a first triode, a second triode, a first diode, a third triode, and a fourth triode;

[0013] The first diode has an anode connected to the drain of the second field effect transistor and a cathode connected to the source of the first transistor;

[0014] The voltage follower, a voltage output terminal is connected to the collector of the first transistor;

[0015] The base of the first triode is connected to the gate of the third field effect transistor;

[0016] The emitter of the third transistor is grounded, and the collector is connected to the base of the fourth transistor;

[0017] The emitter of the fourth transistor is connected to the emitter of the first transistor.

[0018] After the voltage output terminal outputs different reference voltages, the base voltage of the first transistor is adjusted based on the different reference voltages to adjust the self-inductance current release threshold.

[0019] In some possible implementations, the self-inductance current release threshold adjustment module includes a third diode, and the gate and the drain of the third field effect tube are respectively connected to the third diode;

[0020] Wherein, the third diode is used to adjust the gate voltage of the third field effect tube to a preset gate voltage after being turned on, so as to adjust the self-inductance current release threshold.

[0021] In some possible implementations, the self-inductance current release module further includes a filter capacitor for reducing noise, and the gate and the source of the third field effect transistor are respectively connected to the filter capacitor.

[0022] In some possible implementations, the self-inductance current release threshold adjustment module further includes a fourth diode, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor and a control unit;

[0023] The fourth diode has an anode connected to the second resistor and a cathode connected to the sixth resistor;

[0024] The first resistor has one end connected to the control unit and the other end connected to the base of the second transistor;

[0025] The second resistor has one end connected to the anode of the fourth diode and the other end connected to the control unit;

[0026] The third resistor has one end connected to the base of the third transistor and the other end connected to the control unit;

[0027] The fourth resistor has one end connected to the base of the fourth transistor and the other end connected to the collector of the third transistor;

[0028] The fifth resistor has one end connected to the collector of the fourth transistor and the other end grounded;

[0029] The sixth resistor has one end connected to the base of the first transistor and the other end connected to the gate of the third field effect transistor;

[0030] The fourth diode, the first resistor, the second resistor, the third resistor, the fifth resistor and the sixth resistor are used to protect the circuit.

[0031] On the other hand, the present invention provides a self-inductive current release control method, the self-inductive current release control method comprising:

[0032] Controlling the drain voltage of the first field effect transistor to be a preset voltage, and turning on the first field effect transistor based on the preset voltage;

[0033] The second field effect transistor is turned on, so that after the driving current generated in the solenoid valve driving module flows through the solenoid valve coil, the solenoid valve coil generates a magnetic field;

[0034] The second field effect tube is controlled to be cut off, and the drain voltage of the second field effect tube increases until the third field effect tube is turned on when the self-inductance current release threshold is reached, and the freewheeling loop is formed, and the self-inductance current generated by the solenoid valve coil flows in the freewheeling loop.

[0035] In some possible implementations, the self-inductive current release control method further includes:

[0036] turning on the second transistor;

[0037] Controlling the voltage follower to be in a low level state, and turning off the first transistor based on the low level state, so that the self-inductance current release threshold is a first self-inductance current release threshold;

[0038] Controlling the second field effect tube to be cut off, and the drain voltage of the second field effect tube to increase until the source voltage of the third field effect tube is greater than or equal to the first self-inductance current release threshold, and the third field effect tube is turned on;

[0039] The first self-inductance current release threshold is equal to the field effect tube conduction voltage.

[0040] In some possible implementations, the self-inductive current release control method further includes:

[0041] Controlling the second triode to be cut off;

[0042] Turning on the third transistor and the fourth transistor, controlling the voltage follower to output a reference voltage, turning on the second diode and the first transistor based on the reference voltage, the base voltage of the first transistor being the difference between the reference voltage and the turn-on voltage of the second diode, and the self-inductance current release threshold being the second self-inductance current release threshold;

[0043] Controlling the second field effect transistor to be cut off, and increasing the source voltage of the third field effect transistor until the source voltage of the third field effect transistor is greater than or equal to the second self-inductance current release threshold;

[0044] The second self-inductance current release threshold is the sum of the base voltage of the first transistor and the field effect transistor conduction voltage.

[0045] In some possible implementations, the self-inductive current release control method further includes:

[0046] Controlling the first triode, the second triode, the third triode and the fourth triode to be cut off;

[0047] Controlling the output voltage of the voltage follower to be zero;

[0048] Controlling the second field effect transistor to be cut off, turning on the third diode, adjusting the gate voltage of the third field effect transistor to be a preset gate voltage, and adjusting the self-inductance current release threshold to be a third self-inductance current release threshold;

[0049] Controlling the drain voltage of the second field effect transistor to continue to increase until the source voltage of the third field effect transistor is greater than or equal to the third self-inductance current release threshold;

[0050] Wherein, the third self-inductance current release threshold is the sum of the preset gate voltage and the field effect tube conduction voltage.

[0051] In addition, the present invention further provides a solenoid valve device, which includes the above-mentioned self-inductance current release control circuit.

[0052] The self-inductive current release control circuit, method and solenoid valve device proposed in the embodiments of the present invention have the following beneficial effects:

[0053] The embodiment of the present invention sets a self-inductance current release module to be connected to the solenoid valve drive module. When the second field effect tube is turned off, the third field effect tube is turned on to release the self-inductance current generated by the solenoid valve coil through the freewheeling circuit, thereby reducing the heating of the device and enabling high-frequency PWM control. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0055] Figure 1 An existing self-inductive current release circuit provided by an embodiment of the present invention Figure 1 ;

[0056] Figure 2 A self-inductive current release control circuit provided by an embodiment of the present invention Figure 1 ;

[0057] Figure 3 A self-inductive current release control circuit provided by an embodiment of the present invention Figure 2 ;

[0058] Figure 4 A self-inductive current release control method provided by an embodiment of the present invention is a process flow Figure 1 ;

[0059] Figure 5 A self-inductive current release control method provided by an embodiment of the present invention is a process flow Figure 2 ;

[0060] Figure 6 A self-inductive current release control method provided by an embodiment of the present invention is a process flow Figure 3 ;

[0061] Figure 7 A self-inductive current release control method provided by an embodiment of the present invention is a process flow Figure 4 . DETAILED DESCRIPTION

[0062] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0063] It should be noted that the terms "first", "second", etc. in the specification and claims of the embodiments of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this embodiment, unless otherwise specified, the meaning of "multiple" is two or more. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or server comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0064] In order to make the purpose, technical solution and advantages disclosed in the embodiments of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the embodiments of the present invention and are not used to limit the embodiments of the present invention.

[0065] See also Figure 1 , Figure 1 An existing self-inductive current release circuit provided by an embodiment of the present invention Figure 1 As shown in the figure, after the control field effect tube Q4 and field effect tube Q5 are turned on, the solenoid valve coil is powered on, the solenoid valve is opened, and after the control field effect tube Q5 is closed, due to the effect of the coil self-inductance electromotive force, the drain voltage of the field effect tube Q5 increases. When it increases to the conduction voltage of the voltage regulator tube Z3, the field effect tube Q5 is turned on, and the self-inductance current of the solenoid valve is released through the field effect tube Q5. When the self-inductance current is released to close to 0A, the solenoid valve is closed. This process is less than 1ms, meeting the requirements of fast closing. Since the high voltage generated by the coil self-inductance current at the drain of the field effect tube Q5 will affect the life of the field effect tube Q5, it can only be applied to low-frequency PWM control, and high-frequency PWM control cannot be used, otherwise it will cause the voltage regulator tube Z3 and the field effect tube Q5 to heat up seriously or even be damaged.

[0066] To this end, the present invention provides a self-inductive circuit release control circuit, a self-inductive circuit release control method and a solenoid valve device, which can switch the working mode to achieve fast closing and high-frequency PWM control.

[0067] See also Figure 2 , Figure 3 , as shown in the figure, in some possible embodiments, the self-inductive current release control circuit includes a solenoid valve driving module and a self-inductive current release module, and the solenoid valve driving module is connected to the self-inductive current release module;

[0068] The solenoid valve driving module includes a first field effect tube, a solenoid valve coil and a second field effect tube; the self-inductance current release module includes a third field effect tube; the source of the third field effect tube is connected to the drain of the second field effect tube, the drain of the third field effect tube is connected to the source of the first field effect tube, and the source of the second field effect tube is grounded;

[0069] Among them, the third field effect tube is turned on when the source voltage reaches the self-inductance current release threshold, so that the self-inductance current generated by the solenoid valve coil is released in the freewheeling circuit, and the freewheeling circuit is a circuit formed between the solenoid valve coil and the third field effect tube.

[0070] Optionally, the self-inductance current release threshold refers to the minimum source voltage of the third field effect tube. When the minimum source voltage of the third field effect tube reaches the self-inductance current release threshold, the third field effect tube is turned on to form a freewheeling loop, and the self-inductance current is released in the freewheeling loop.

[0071] The embodiment of the present invention sets a self-inductance current release module to be connected to the solenoid valve drive module. When the second field effect tube is turned off, the third field effect tube is turned on to release the self-inductance current generated by the solenoid valve coil through the freewheeling circuit, thereby reducing the heating of the device and enabling high-frequency PWM control.

[0072] The self-inductance current release control circuit provided by the present invention can operate in at least three working modes, including a high-frequency PWM control mode, an adjustable response control mode and a forced fast response mode, and can achieve different self-inductance current release thresholds in the three working modes.

[0073] Please continue to see Figure 2 ,like Figure 2 As shown, a self-inductive current release control circuit provided by an embodiment of the present invention may include three modules, namely, a solenoid valve driving module, a self-inductive current release module and a self-inductive current release threshold adjustment module.

[0074] In some possible embodiments, the self-inductance current release control circuit further includes a self-inductance current release threshold adjustment module for adjusting the self-inductance current release threshold;

[0075] The self-inductive current release threshold adjustment module is connected to the solenoid valve driving module, and is connected to the self-inductive current release module through the gate of the third field effect transistor;

[0076] Wherein, the self-inductance current release threshold adjustment module adjusts the self-inductance current release threshold.

[0077] The embodiment of the present invention changes the self-inductance current release threshold by setting a self-inductance current release threshold adjustment module. The self-inductance current release threshold is related to the response speed of the solenoid valve. The higher the self-inductance current release threshold, the faster the solenoid valve response speed. Therefore, by increasing the self-inductance current release threshold, a faster solenoid valve response speed can be obtained, which meets the fast response requirements.

[0078] Please continue to see Figure 3 As shown in the figure, in some possible embodiments, the present invention provides a self-inductive current release control circuit, which can be switched to an adjustable response control mode based on the following structure of the self-inductive current control circuit:

[0079] The self-inductance current release threshold adjustment module includes a voltage follower tracker, a first transistor, a second transistor, a first diode, a third transistor, and a fourth transistor;

[0080] The first diode has an anode connected to the drain of the second field effect transistor, and a cathode connected to the source of the first transistor.

[0081] Optionally, the first diode D1 is used to prevent the voltage follower tracker from outputting to the source of the second field effect transistor Q2 through the voltage output terminal, the second diode D2, the sixth resistor R6, and the bias resistor R7, causing problems in chip diagnosis.

[0082] The voltage follower has a voltage output terminal connected to the collector of the first transistor.

[0083] Optionally, a voltage follower tracker is used to adjust the base voltage V Q5_bAdjustment is performed. The voltage follower tracker has four ports: B1, B2, B3, and B4. The B1 port is connected to the solenoid valve coil drive module through a wire. The B2 port is connected to the collector of the second diode D2 and the first transistor Q5 through a wire. The B3 port is an enable port, which is connected to the control unit through a second resistor R2, receives an enable signal sent by the control unit, and drives the voltage follower tracker to work. The B4 port is a voltage input port, which is electrically connected to the digital-to-analog converter DAC through the C2 port. The C1 port is connected to the A3 port of the control unit to receive different reference voltages. After the voltage follower tracker receives the reference voltage through the B4 port, the reference voltage Vref is output through the voltage output terminal B2, thereby adjusting the base voltage V of the first transistor Q5. Q5_b .

[0084] The base of the first transistor is connected to the gate of the third field effect transistor.

[0085] Optionally, the base of the first transistor Q5 is connected to the gate of the third field effect transistor Q3, so by adjusting the base voltage V Q5_b , which can indirectly adjust the self-inductance current release threshold of the third field effect transistor Q3. Since the field effect transistor conduction voltage Vth of the third field effect transistor Q3 remains unchanged, when the third field effect transistor Q3 is turned on, the difference between the source voltage and the gate voltage of the third field effect transistor Q3 should be greater than or equal to the field effect transistor conduction voltage Vth.

[0086] The emitter of the third transistor is grounded, and the collector is connected to the base of the fourth transistor.

[0087] The emitter of the fourth transistor is connected to the emitter of the first transistor.

[0088] Optionally, the circuit current can be amplified by setting the third transistor Q4 and the fourth transistor Q6 in parallel. After the voltage output terminal B2 outputs different reference voltages Vref, the base voltage V of the first transistor Q5 is adjusted based on the different reference voltages Vref. Q5_b , to adjust the self-inductance current release threshold.

[0089] The embodiment of the present invention adjusts the base voltage of the first transistor by outputting a reference voltage through a voltage follower tracker, thereby affecting the self-inductance current release threshold. On the basis of high-frequency PWM, the reference voltage can be flexibly adjusted to obtain different self-inductance current release thresholds, so that the response speed of the solenoid valve can be adjusted as needed. The larger the reference voltage, the higher the self-inductance current release threshold and the faster the response speed of the solenoid valve.

[0090] Please continue to see Figure 3As shown in the figure, in some possible embodiments, the present invention provides a self-inductive current release control circuit, which can be switched to a forced fast response control mode based on the following structure of the self-inductive current control circuit:

[0091] The self-inductance current release threshold adjustment module includes a third diode, and the gate and the drain of the third field effect tube are respectively connected to the third diode;

[0092] Optionally, the third diode Z2 may be a voltage regulator having a function of stabilizing circuit voltage. The third diode is used to adjust the gate voltage of the third field effect transistor to a preset gate voltage after being turned on, so as to adjust the self-inductance current release threshold.

[0093] Optionally, the preset gate voltage is the sum of the drain voltage at the D terminal of the second field effect tube Q2 and the regulated voltage of the third diode Z2. Since the third diode Z2 has a voltage stabilizing effect, the gate voltage at the G terminal of the third field effect tube Q3 is the preset gate voltage and remains unchanged. In order to turn on the third field effect tube Q3, the difference between the source voltage and the gate voltage of the third field effect tube Q3 should be greater than or equal to the field effect tube conduction voltage Vth. Therefore, the self-inductance current release threshold is adjusted to the sum of the preset gate voltage and the field effect tube conduction voltage Vth by setting the voltage regulator.

[0094] The embodiment of the present invention provides a diode with a voltage stabilizing function in the self-inductive current release threshold adjustment module, and connects the gate and drain of the third field effect tube, so that after the third diode is turned on, the gate voltage of the third field effect tube is limited to a preset gate voltage, thereby increasing the self-inductive current release threshold, delaying the time when the self-inductive current starts to be released, and thus reducing the follow-flow time of the self-inductive current.

[0095] Please continue to see Figure 3 As shown in the figure, in some possible embodiments, the self-inductance current release module also includes a filter capacitor for reducing noise, and the gate and source of the third field effect tube are respectively connected to the filter capacitor.

[0096] Optionally, the self-inductance current release module may also be provided with a filter capacitor C1.

[0097] The embodiment of the present invention can reduce the influence of noise on the circuit by setting a filter capacitor in the self-inductive current release module, and the filter capacitor can also absorb voltage fluctuations to keep the output voltage stable. When the voltage increases, the filter capacitor will absorb excess energy; when the voltage decreases, the filter capacitor will release energy, thereby ensuring the stable operation of the circuit and ensuring the stability and reliability of the circuit.

[0098] Please continue to see Figure 3, as shown in the figure, in some possible embodiments, the self-inductance current release threshold adjustment module also includes a fourth diode, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor and a control unit.

[0099] Optionally, the control unit MCU is provided with a plurality of ports, such as A1, A2, A3, and A4, and by setting these ports high or low, the switching of the working mode is controlled and the self-inductance current release threshold is adjusted.

[0100] The fourth diode has an anode connected to the second resistor and a cathode connected to the sixth resistor.

[0101] Optionally, the fourth diode D3 has an anode connected to the second resistor R2 and a cathode connected to the sixth resistor R6.

[0102] One end of the first resistor is connected to the control unit, and the other end is connected to the base of the second transistor.

[0103] Optionally, one end of the first resistor R1 is connected to a port of the control unit A1, and the other end is connected to a base of the second transistor Q7.

[0104] One end of the second resistor is connected to the anode of the fourth diode, and the other end is connected to the control unit.

[0105] Optionally, the second resistor R2 has one end connected to the anode of the fourth diode D3 and one end connected to the A4 port of the control unit.

[0106] The third resistor has one end connected to the base of the third transistor and the other end connected to the control unit.

[0107] Optionally, the third resistor R3 has one end connected to the base of the third transistor Q4 and one end connected to the A2 port of the control unit.

[0108] The fourth resistor has one end connected to the base of the fourth transistor and the other end connected to the collector of the third transistor.

[0109] Optionally, the fourth resistor R4 has one end connected to the base of the fourth transistor Q6 , and the other end connected to the collector of the third transistor Q4 .

[0110] The fifth resistor has one end connected to the collector of the fourth transistor and the other end grounded;

[0111] Optionally, the fifth resistor R5 has one end connected to the collector of the fourth transistor Q6 and one end grounded.

[0112] The sixth resistor has one end connected to the base of the first transistor and the other end connected to the gate of the third field effect transistor.

[0113] Optionally, a sixth resistor R6 has one end connected to the base of the first transistor Q5 and the other end connected to the gate G of the third field effect transistor Q3.

[0114] The fourth diode, the first resistor, the second resistor, the third resistor, the fifth resistor and the sixth resistor are used to protect the circuit.

[0115] Optionally, a bias resistor R7 may be further provided in the self-inductance current release module, and the gate G and the source S of the third field effect transistor Q3 are respectively connected to the bias resistor R7, which can improve the stability and safety of the circuit.

[0116] The embodiment of the present invention can protect the circuit, ensure the safety of the control unit port, prevent misconnection, and enhance the circuit stability by setting the first resistor, the second resistor, the third resistor, the fourth resistor, the fifth resistor and the sixth resistor in the self-inductance current release threshold adjustment module. By setting the fourth diode, the second transistor and the voltage follower are prevented from being turned on at the same time, which causes the voltage output end of the voltage follower to be directly grounded through the second transistor and burned due to overcurrent, thereby improving the safety of the circuit.

[0117] Figure 4 A self-inductive current release control method provided by an embodiment of the present invention is a process flow Figure 1 . This specification provides method operation steps as described in the embodiments or flowcharts, but may include more or fewer operation steps based on routine or non-creative work. The order of steps listed in the embodiments is only one way of executing the steps among many orders, and does not represent the only order of execution. When the actual system or server product is executed, it can be executed in the order of the method shown in the embodiments or the drawings or in parallel (for example, in a parallel processor or multi-threaded processing environment). Specifically, Figure 4 As shown, the self-inductance current release control method includes:

[0118] S101: Controlling the drain voltage of the first field effect transistor to be a preset voltage, and turning on the first field effect transistor based on the preset voltage.

[0119] Optionally, a power supply device may be provided in the solenoid valve control module to output a preset voltage to the drain of the first field effect transistor Q1 , and to power on the upper end of the solenoid valve coil by turning on the first field effect transistor Q1 .

[0120] S103: Turning on the second field effect transistor, after the driving current generated in the solenoid valve driving module flows through the solenoid valve coil, the solenoid valve coil generates a magnetic field;

[0121] Optionally, a control unit can be set in the self-inductance current release threshold adjustment module. For example, the control unit controls the on and off of the second field effect transistor Q2. Preferably, when the driving capability or driving voltage of the control unit is insufficient, a pre-driving circuit or pre-driving chip can be added between the control unit and the second field effect transistor Q2 to increase the driving capability and driving voltage.

[0122] Optionally, after the second field effect transistor Q2 is turned on, the solenoid valve driving module forms a loop, driving current flows through the solenoid valve coil, and the solenoid valve coil generates a magnetic field due to the electromagnetic effect.

[0123] S105: Control the second field effect transistor to be cut off, and the drain voltage of the second field effect transistor increases until the third field effect transistor is turned on when the self-inductance current release threshold is reached, and the freewheeling loop is formed, and the self-inductance current generated by the solenoid valve coil flows in the freewheeling loop.

[0124] Optionally, after the second field effect transistor Q2 is controlled to be cut off, a self-inductance current is generated in the solenoid valve coil, and the self-inductance current continuously accumulates at the drain of the second field effect transistor Q2, and the drain voltage of the second field effect transistor Q2 continuously increases. Since the source of the third field effect transistor Q3 is connected to the drain of the second field effect transistor Q2, the source voltage of the third field effect transistor Q3 also changes accordingly.

[0125] Optionally, the self-inductance current release threshold refers to a minimum source voltage of the third field effect transistor Q3 that enables a freewheeling loop to be formed and the self-inductance current to be released in the freewheeling loop.

[0126] The embodiment of the present invention sets a self-inductance current release module to slowly release the self-inductance current generated in the solenoid valve coil through the freewheeling loop formed in the self-inductance current release module, thereby reducing the heating of the circuit, enabling the switch of the second field effect tube to be controlled by high-frequency PWM, reducing circuit noise, and improving circuit stability.

[0127] See also Figure 5 , Figure 5 A self-inductive current release control method provided by an embodiment of the present invention is a process flow Figure 2 As shown in the figure, in some possible embodiments, the present invention provides a self-inductive current release control method for adjusting the working mode to a high-frequency PWM control mode, and the self-inductive current release control method further includes:

[0128] S201: Turn on the second transistor.

[0129] S203: Control the voltage follower to be in a low level state, and cut off the first transistor based on the low level state, so that the self-inductance current release threshold is the first self-inductance current release threshold.

[0130] Optionally, the control unit can control the voltage follower tracker to be in a low level state, and since the voltage output terminal of the voltage follower tracker is connected to the base and collector of the first transistor Q5, the first transistor Q5 is turned off. Further, since the base of the first transistor Q5 is connected to the gate of the third field effect transistor Q3, the gate voltage of the third field effect transistor Q3 is zero.

[0131] Furthermore, the third field effect transistor Q3 is a PMOS tube. To turn on the third field effect transistor Q3, the voltage difference between the source voltage and the gate voltage should be greater than or equal to the field effect transistor conduction voltage. Therefore, the first self-inductance current release threshold is equal to the field effect transistor conduction voltage Vth.

[0132] S205: Control the second field effect transistor to be turned off, and the drain voltage of the second field effect transistor increases until the source voltage of the third field effect transistor is greater than or equal to the first self-inductance current release threshold, and the third field effect transistor is turned on.

[0133] It should be noted that after the second field effect transistor Q2 is turned off, the self-inductance current in the solenoid valve coil accumulates at the drain of the second field effect transistor Q2, causing the drain voltage at the D end of the second field effect transistor Q2 and the source voltage at the S end of the third field effect transistor Q3 to increase, until the source voltage at the S end of the third field effect transistor Q3 increases to the self-inductance current release threshold, and then the third field effect transistor Q3 is turned on. Corresponding to different working modes, the self-inductance current release thresholds are the first self-inductance current release threshold, the second self-inductance current release threshold, and the third self-inductance current release threshold, which will not be repeated below.

[0134] The embodiment of the present invention controls the base voltage of the first transistor to be zero, adjusts the self-inductance current release threshold to the first self-inductance current release threshold, and turns on the third field effect tube when the source voltage of the third field effect tube reaches the first self-inductance current release threshold, and forms a freewheeling loop, so that the self-inductance current generated by the solenoid valve coil can be slowly released in the freewheeling loop. Compared with the case where the third field effect tube is not introduced, the circuit heating caused by the freewheeling is reduced, and high-frequency PWM control can be supported.

[0135] See also Figure 6 , Figure 6 A self-inductive current release control method provided by an embodiment of the present invention is a process flow Figure 3 As shown in the figure, in some possible embodiments, the present invention provides a self-inductive current release control method for adjusting the working mode to an adjustable response control mode, and the self-inductive current release control method further includes:

[0136] S301: Control the second transistor to be cut off.

[0137] Optionally, by setting the control unit A1 port low, the second transistor Q7 is turned off, so that the gate voltage of the third field effect transistor is only adjusted by the voltage follower tracker.

[0138] S303: Turn on the third transistor and the fourth transistor, control the voltage follower to output a reference voltage, turn on the second diode and the first transistor based on the reference voltage, the base voltage of the first transistor is the difference between the reference voltage and the turn-on voltage of the second diode, and the self-inductance current release threshold is the second self-inductance current release threshold.

[0139] Optionally, by setting the A2 and A4 ports of the control unit high, the voltage follower tracker outputs the reference voltage Vref through the voltage output port B2, and turns on the third transistor Q4, the fourth transistor Q6, the second diode D2 and the first transistor Q5, the control unit A3 port is set high to drive the DAC and make the DAC output the reference voltage Vref to the voltage follower B4 port, so that the voltage follower tracker receives the reference voltage Vref, and the conduction voltage of the second diode D2 is V D2 , then the base voltage of the first transistor V Q5_b = (Vref-Vth), the gate voltage of the third field effect transistor Q3 is also (Vref-V D2 ), since the field effect tube conduction voltage of the third field effect tube is Vth, the second self-inductance current release threshold is (Vref-V D2 +Vth).

[0140] S305: Control the second field effect transistor to be cut off, and the source voltage of the third field effect transistor to increase until the source voltage of the third field effect transistor is greater than or equal to the second self-inductance current release threshold.

[0141] Wherein, the second self-inductance current release threshold is, the base voltage V Q5_b The sum of the field effect tube conduction voltage Vth.

[0142] It should be noted that the adjustable response control mode is implemented on the basis of the high-frequency PWM control mode. By controlling the value of the reference voltage Vref, the base voltage V of the first transistor Q5 can be adjusted. Q5_b The size of the second self-inductance current release threshold is adjusted to obtain different sizes of the second self-inductance current release threshold. In the adjustable response control mode, the second self-inductance current release threshold is adjustable.

[0143] The embodiment of the present invention turns on the third transistor and the fourth transistor, controls the voltage follower tracker to output reference voltages of different magnitudes, thereby adjusting the first transistor to have different base voltages, and indirectly adjusting the second self-inductive current release threshold. Within a certain range, by adjusting the reference voltage, a faster solenoid valve response speed can be obtained. The larger the output reference voltage, the larger the second self-inductive current release threshold, the later the start time of the self-inductive current release in the freewheeling circuit, the shorter the freewheeling time, and the faster the response speed of the solenoid valve.

[0144] See also Figure 7 , Figure 7 A self-inductive current release control method provided by an embodiment of the present invention is a process flow Figure 4 As shown in the figure, in some possible embodiments, the present invention provides a self-inductive current release control method for adjusting the working mode to a forced fast response mode. In some possible embodiments, the self-inductive current release control method further includes:

[0145] S401: Control the first transistor, the second transistor, the third transistor and the fourth transistor to be cut off.

[0146] Optionally, by controlling the first transistor Q5, the second transistor, the third transistor Q4 and the fourth transistor Q6 to be cut off, the gate of the third field effect transistor Q3 is connected to the voltage output terminal B2 of the voltage follower tracker through the second diode D2, and the gate voltage of the third field effect transistor Q3 is regulated by the voltage output terminal B2 of the voltage follower tracker.

[0147] S403: Control the output voltage of the voltage follower tracker to be zero.

[0148] Optionally, the output voltage of the voltage follower tracker reaches the gate of the third field effect transistor Q3 through the second diode D2, so that the gate voltage is zero.

[0149] S405: Control the second field effect transistor to be turned off, turn on the third diode, adjust the gate voltage of the third field effect transistor to a preset gate voltage, and adjust the self-inductance current release threshold to a third self-inductance current release threshold.

[0150] Optionally, after the second field effect transistor Q2 is turned off, the source voltage of the third field effect transistor Q3 increases to turn on the third diode Z2. Since the voltage regulator has a voltage stabilizing effect, the source voltage of the third field effect transistor Q3 increases to the point where the third diode Z2 is turned on, and the gate voltage of the third field effect transistor Q3 is limited to the sum of the drain voltage and the stabilizing voltage Vz.

[0151] S407: Control the drain voltage of the second field effect transistor to continue to increase until the source voltage of the third field effect transistor is greater than or equal to the third self-inductance current release threshold.

[0152] Optionally, the source voltage of the third field effect transistor Q3 is controlled to continue to rise to a third self-inductance current release threshold, and the third field effect transistor Q3 is turned on. The third self-inductance current release threshold is the sum of the preset gate voltage and the field effect transistor conduction voltage V th sum.

[0153] Furthermore, the third self-inductance current release threshold is greater than the first self-inductance current release threshold. Since the preset voltage provided by the power supply device to the voltage follower tracker is greater than the base voltage output by the voltage follower tracker to the first transistor Q5, the third self-inductance current release threshold is also greater than the second self-inductance current release threshold. Therefore, the self-inductance current release threshold in the forced fast response mode is the maximum value, and the solenoid valve in this mode has the fastest response speed and the shortest follow-up time.

[0154] The embodiment of the present invention increases the third self-inductance current release threshold by setting a voltage regulator in the self-inductance current release threshold control module, thereby delaying the conduction time of the third field effect tube, delaying the time point when the self-inductance current starts to be released in the freewheeling circuit, making the freewheeling time the shortest and the response speed of the solenoid valve the fastest.

[0155] In addition, the present invention further provides a solenoid valve device, which includes the above-mentioned self-inductance current release control circuit.

[0156] The implementation of the embodiments of the present invention has the following beneficial effects:

[0157] 1. In the embodiment of the present invention, a self-inductance current release module is connected to the solenoid valve drive module. When the second field effect tube is turned off, the third field effect tube is turned on, so that the self-inductance current generated by the solenoid valve coil is released through the freewheeling circuit, thereby reducing the heating of the device and being able to be controlled by high-frequency PWM.

[0158] 2. The embodiment of the present invention changes the self-inductance current release threshold by setting a self-inductance current release threshold adjustment module. The self-inductance current release threshold is related to the response speed of the solenoid valve. The higher the self-inductance current release threshold, the faster the solenoid valve response speed. Therefore, by increasing the self-inductance current release threshold, a faster solenoid valve response speed can be obtained, which meets the fast response requirements.

[0159] 3. The embodiment of the present invention adjusts the base voltage of the first transistor by outputting a reference voltage through a voltage follower, thereby affecting the self-inductance current release threshold. On the basis of high-frequency PWM, the reference voltage can be flexibly adjusted to obtain different self-inductance current release thresholds, so that the response speed of the solenoid valve can be adjusted as needed. The larger the reference voltage, the higher the self-inductance current release threshold and the faster the response speed of the solenoid valve.

[0160] 4. The embodiment of the present invention sets a diode with a voltage stabilizing function in the self-inductive current release threshold adjustment module, and connects the gate and drain of the third field effect tube, so that after the third diode is turned on, the gate voltage of the third field effect tube is limited to a preset gate voltage, thereby increasing the self-inductive current release threshold, delaying the time when the self-inductive current starts to be released, and thus reducing the follow-up time of the self-inductive current.

[0161] 5. The embodiment of the present invention can reduce the influence of noise on the circuit by setting a filter capacitor in the self-inductive current release module. The filter capacitor can also absorb voltage fluctuations to keep the output voltage stable. When the voltage increases, the filter capacitor will absorb excess energy; when the voltage decreases, the filter capacitor will release energy, thereby ensuring the stable operation of the circuit and ensuring the stability and reliability of the circuit.

[0162] 6. The embodiment of the present invention can protect the circuit, ensure the safety of the control unit port, prevent misconnection, and enhance the circuit stability by setting the first resistor, the second resistor, the third resistor, the fourth resistor, the fifth resistor and the sixth resistor in the self-inductance current release threshold adjustment module. By setting the fourth diode, the second transistor and the voltage follower are prevented from being turned on at the same time, which causes the voltage output end of the voltage follower to be directly grounded through the second transistor and burned due to overcurrent, thereby improving the safety of the circuit.

[0163] 7. The embodiment of the present invention sets a self-inductance current release module to slowly release the self-inductance current generated in the solenoid valve coil through the freewheeling loop formed in the self-inductance current release module, thereby reducing the heating of the circuit, enabling the switch of the second field effect tube to be controlled by high-frequency PWM, reducing circuit noise, and improving circuit stability.

[0164] 8. The embodiment of the present invention controls the base voltage of the first transistor to be zero, adjusts the self-inductance current release threshold to the first self-inductance current release threshold, and turns on the third field effect tube when the source voltage of the third field effect tube reaches the first self-inductance current release threshold, and forms a freewheeling loop, so that the self-inductance current generated by the solenoid valve coil can be slowly released in the freewheeling loop. Compared with the case where the third field effect tube is not introduced, the circuit heating caused by the freewheeling is reduced, and high-frequency PWM control can be supported.

[0165] 9. The embodiment of the present invention turns on the third transistor and the fourth transistor and controls the voltage follower to output reference voltages of different magnitudes, thereby adjusting the first transistor to have different base voltages and indirectly adjusting the second self-inductive current release threshold. Within a certain range, by adjusting the reference voltage, a faster solenoid valve response speed can be obtained. The larger the output reference voltage, the larger the second self-inductive current release threshold, the later the start time of the self-inductive current release in the freewheeling circuit, the shorter the freewheeling time, and the faster the response speed of the solenoid valve.

[0166] It should be noted that the self-inductive current release threshold control circuit embodiment, the self-inductive current release threshold control method embodiment and the solenoid valve device provided in the embodiments of the present invention are based on the same inventive concept.

[0167] It should be noted that the sequence of the embodiments of the present invention described above is for description only and does not represent the advantages and disadvantages of the embodiments. The above describes specific embodiments of this specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0168] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device and server embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiments.

[0169] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A self-inductive current release control circuit, characterized in that: The self-inductive current release control circuit comprises a solenoid valve driving module and a self-inductive current release module, wherein the solenoid valve driving module is connected to the self-inductive current release module; The solenoid valve driving module includes a first field effect tube, a solenoid valve coil and a second field effect tube; the self-inductance current release module includes a third field effect tube; the source of the third field effect tube is connected to the drain of the second field effect tube, the drain of the third field effect tube is connected to the source of the first field effect tube, and the source of the second field effect tube is grounded; Among them, the third field effect tube is turned on when the source voltage reaches the self-inductance current release threshold, so that the self-inductance current generated by the solenoid valve coil is released in the freewheeling circuit, and the freewheeling circuit is a circuit formed between the solenoid valve coil and the third field effect tube.

2. The self-inductive current release control circuit according to claim 1, characterized in that: The self-inductance current release control circuit also includes a self-inductance current release threshold adjustment module for adjusting the self-inductance current release threshold; The self-inductive current release threshold adjustment module is connected to the solenoid valve driving module, and is connected to the self-inductive current release module through the gate of the third field effect transistor; Wherein, the self-inductance current release threshold adjustment module adjusts the self-inductance current release threshold.

3. The self-inductive current release control circuit according to claim 2, characterized in that: The self-inductance current release threshold adjustment module includes a voltage follower, a first triode, a second triode, a first diode, a third triode, and a fourth triode; The first diode has an anode connected to the drain of the second field effect transistor and a cathode connected to the source of the first transistor; The voltage follower, a voltage output terminal is connected to the collector of the first transistor; The base of the first triode is connected to the gate of the third field effect transistor; The emitter of the third transistor is grounded, and the collector is connected to the base of the fourth transistor; The emitter of the fourth transistor is connected to the emitter of the first transistor. After the voltage output terminal outputs different reference voltages, the base voltage of the first transistor is adjusted based on the different reference voltages to adjust the self-inductance current release threshold.

4. The self-inductive current release control circuit according to claim 2, characterized in that: The self-inductance current release threshold adjustment module includes a third diode, and the gate and the drain of the third field effect tube are respectively connected to the third diode; Wherein, the third diode is used to adjust the gate voltage of the third field effect tube to a preset gate voltage after being turned on, so as to adjust the self-inductance current release threshold.

5. The self-inductive current release control circuit according to claim 1, characterized in that: The self-inductance current release module also includes a filter capacitor for reducing noise, and the gate and source of the third field effect tube are respectively connected to the filter capacitor.

6. The self-inductive current release control circuit according to claim 3, characterized in that: The self-inductance current release threshold adjustment module also includes a fourth diode, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor and a control unit; The fourth diode has an anode connected to the second resistor and a cathode connected to the sixth resistor; The first resistor has one end connected to the control unit and the other end connected to the base of the second transistor; The second resistor has one end connected to the anode of the fourth diode and the other end connected to the control unit; The third resistor has one end connected to the base of the third transistor and the other end connected to the control unit; The fourth resistor has one end connected to the base of the fourth transistor and the other end connected to the collector of the third transistor; The fifth resistor has one end connected to the collector of the fourth transistor and the other end grounded; The sixth resistor has one end connected to the base of the first transistor and the other end connected to the gate of the third field effect transistor; The fourth diode, the first resistor, the second resistor, the third resistor, the fifth resistor and the sixth resistor are used to protect the circuit.

7. A self-inductive current release control method, characterized in that: The self-inductive current release control method is implemented based on the self-inductive current release control circuit according to any one of claims 1 to 6, and the self-inductive current release control method includes: Controlling the drain voltage of the first field effect transistor to be a preset voltage, and turning on the first field effect transistor based on the preset voltage; The second field effect transistor is turned on, so that after the driving current generated in the solenoid valve driving module flows through the solenoid valve coil, the solenoid valve coil generates a magnetic field; The second field effect tube is controlled to be cut off, and the drain voltage of the second field effect tube increases until the third field effect tube is turned on when the self-inductance current release threshold is reached, and the freewheeling loop is formed, and the self-inductance current generated by the solenoid valve coil flows in the freewheeling loop.

8. The self-inductive current release control method according to claim 7, wherein the self-inductive current release control method is implemented based on the self-inductive current release control circuit according to claim 3, and the self-inductive current release control method further comprises: turning on the second transistor; Controlling the voltage follower to be in a low level state, and turning off the first transistor based on the low level state, so that the self-inductance current release threshold is a first self-inductance current release threshold; Controlling the second field effect tube to be cut off, and the drain voltage of the second field effect tube to increase until the source voltage of the third field effect tube is greater than or equal to the first self-inductance current release threshold, and the third field effect tube is turned on; The first self-inductance current release threshold is equal to the field effect tube conduction voltage.

9. The self-inductive current release control method according to claim 7, characterized in that: The self-inductive current release control method is implemented based on the self-inductive current release control circuit according to claim 3, and the self-inductive current release control method further includes: Controlling the second triode to be cut off; Turning on the third transistor and the fourth transistor, controlling the voltage follower to output a reference voltage, turning on the second diode and the first transistor based on the reference voltage, the base voltage of the first transistor being the difference between the reference voltage and the turn-on voltage of the second diode, and the self-inductance current release threshold being the second self-inductance current release threshold; Controlling the second field effect transistor to be cut off, and increasing the source voltage of the third field effect transistor until the source voltage of the third field effect transistor is greater than or equal to the second self-inductance current release threshold; The second self-inductance current release threshold is the sum of the base voltage of the first transistor and the field effect transistor conduction voltage.

10. The self-inductive current release control method according to claim 7, characterized in that: The self-inductive current release control method is implemented based on the self-inductive current release control circuit according to claim 4, and the self-inductive current release control method further includes: Controlling the first triode, the second triode, the third triode and the fourth triode to be cut off; Controlling the output voltage of the voltage follower to be zero; Controlling the second field effect transistor to be cut off, turning on the third diode, adjusting the gate voltage of the third field effect transistor to be a preset gate voltage, and adjusting the self-inductance current release threshold to be a third self-inductance current release threshold; Controlling the drain voltage of the second field effect transistor to continue to increase until the source voltage of the third field effect transistor is greater than or equal to the third self-inductance current release threshold; Wherein, the third self-inductance current release threshold is the sum of the preset gate voltage and the field effect tube conduction voltage.

11. A solenoid valve device, characterized in that: The solenoid valve device comprises the self-inductance current release control circuit as described in any one of claims 1-6.

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