Piezoelectric ceramic double loop driving circuit for piezoelectric injection valve

Abstract

The application discloses a piezoelectric ceramic double-loop driving circuit for a piezoelectric injection valve, which comprises a main control circuit, a charging switch circuit, a voltage sampling circuit, a current sampling circuit, a constant-current charging control circuit I and a constant-current charging control circuit II; the corresponding ends of the main control circuit are electrically connected with the corresponding ends of the voltage sampling circuit, the charging switch circuit, the current sampling circuit, the constant-current charging control circuit I and the constant-current charging control circuit II; the corresponding ends of the charging switch circuit are also electrically connected with the corresponding ends of the voltage sampling circuit, the current sampling circuit, the constant-current charging control circuit I and the constant-current charging control circuit II; the constant-current charging control circuit I, the current sampling circuit and the constant-current charging control circuit II are arranged in parallel; the application controls the charging and discharging of the ceramic through the current and voltage double-loop, so that the change rate of the charging and discharging of the ceramic tends to be constant, and the expensive high-voltage operational amplifier is not needed, thereby reducing the circuit cost.

Description

Technical Field

[0001] This invention relates to the field of piezoelectric ceramic technology for piezoelectric injection valves, and particularly to a dual-loop drive circuit for piezoelectric ceramics in a piezoelectric injection valve. Background Technology

[0002] The piezoelectric spray valve achieves the spraying of various adhesives by controlling the expansion and contraction deformation of the piezoelectric ceramic to drive the movement of a spring structure. The deformation of the piezoelectric ceramic is controlled by the voltage applied across its terminals; different voltages result in different displacements. The conventional approach is to drive the ceramic by controlling the voltage across its terminals, using a high-voltage operational amplifier (op-amp). However, high-voltage op-amps are expensive, increasing circuit costs. This solution achieves a dual-control loop of current and voltage to drive the piezoelectric ceramic through a voltage-driven mechanism.

[0003] Piezoelectric ceramics are capacitive, and their voltage is changed by charging and discharging them with a constant current. The piezoelectric inverse effect is a mechanical structure that drives adhesive spraying by deforming the piezoelectric ceramic. This solution is a current-controlled piezoelectric ceramic driving scheme, which can effectively drive the piezoelectric ceramic. Summary of the Invention

[0004] This invention provides a dual-loop drive circuit for a piezoelectric ceramic jet valve. The piezoelectric ceramic is driven by a dual control circuit of current and voltage, thereby achieving rapid voltage control at both ends of the piezoelectric ceramic. Due to the inverse piezoelectric effect, the ceramic deformation displacement changes rapidly, controlling the piezoelectric valve to jet glue at high speed.

[0005] To achieve the above objectives, the present invention provides a piezoelectric ceramic dual-loop drive circuit for a piezoelectric injection valve, comprising: a main control circuit, a charging switch circuit, a voltage sampling circuit, a current sampling circuit, a constant current charging control circuit one, and a constant current charging control circuit two.

[0006] The corresponding terminals of the main control circuit are electrically connected to the corresponding terminals of the voltage sampling circuit, the charging switch circuit, the current sampling circuit, the constant current charging control circuit one, and the constant current charging control circuit two, respectively.

[0007] The corresponding terminals of the charging switch circuit are also electrically connected to the corresponding terminals of the voltage sampling circuit, the current sampling circuit, the constant current charging control circuit one, and the constant current charging control circuit two, respectively; the constant current charging control circuit one, the current sampling circuit, and the constant current charging control circuit two are arranged in parallel.

[0008] The charging switch circuit includes field-effect transistors Q1, Q2, and Q3. When the piezoelectric ceramic is charging, field-effect transistor Q1 is closed, field-effect transistor Q2 is open, and field-effect transistor Q3 operates in the linear region to control the charging speed of Q3. When the piezoelectric ceramic is discharging, field-effect transistor Q1 is open, field-effect transistor Q2 operates in the linear region to control the discharging speed of field-effect transistor Q2, and field-effect transistor Q3 is closed.

[0009] Preferably, the main control circuit is an MCU.

[0010] Preferably, the voltage sampling circuit includes resistor R8, resistor R9, and operational amplifier UA2; the positive terminal of operational amplifier UA2 is electrically connected to one end of resistor R8 and resistor R9 respectively, and the output terminal of operational amplifier UA2 is electrically connected to the negative terminal of operational amplifier UA2 and the corresponding terminal of MCU respectively; the other end of resistor R8 and the other end of resistor R9 are electrically connected to the corresponding terminal of charging switch circuit respectively.

[0011] Preferably, the charging switch circuit further includes a transistor Q4, a battery, resistors R12, R13, RS1, and a crystal oscillator Y1; the positive terminal of the battery is electrically connected to one end of resistor R12, the source of the field-effect transistor Q1, and the other end of resistor R8; the negative terminal of the battery is electrically connected to the corresponding terminal of the current sampling circuit, one end of resistor RS1, and the other end of resistor R9, and grounded; the other end of resistor R12 is electrically connected to the gate of the field-effect transistor Q1 and one end of resistor R13; the other end of resistor R13 is grounded through transistor Q4. The corresponding terminal of transistor Q4 is also electrically connected to the corresponding terminal of MCU; the drain of field-effect transistor Q1 is electrically connected to the drain of field-effect transistor Q2 and one end of crystal oscillator Y1; the gate of field-effect transistor Q2 is electrically connected to the corresponding terminal of constant current charging control circuit one; the source of field-effect transistor Q2 is electrically connected to the drain of field-effect transistor Q3 and the other end of crystal oscillator Y1; the gate of field-effect transistor Q3 is electrically connected to the corresponding terminal of constant current charging control circuit two; and the source of field-effect transistor Q3 is electrically connected to the current sampling circuit and the other end of resistor RS1.

[0012] Preferably, the current sampling circuit includes resistors R1, R2, R3, and R4, and operational amplifier U3A; the positive terminal of operational amplifier U3A is electrically connected to one end of resistors R3 and R1, and the negative terminal of operational amplifier U3A is electrically connected to one end of resistors R4 and R2, respectively; the other end of resistor R3 is grounded, and the other end of resistor R1 is electrically connected to the source of field-effect transistor Q3; the other end of resistor R4 is electrically connected to the output terminal of operational amplifier U3A, a corresponding terminal of constant current charging control circuit one, a corresponding terminal of constant current charging control circuit two, and a corresponding terminal of MCU, respectively; and the other end of resistor R2 is electrically connected to the negative terminal of the battery.

[0013] Preferably, the constant current charging control circuit includes resistor R10, resistor R14, transistor Q5, diode D1, and error amplifier circuit 1. The first terminal of transistor Q5 is electrically connected to one terminal of diode D1, the gate of field-effect transistor Q2, and one terminal of resistor R10. The second terminal of transistor Q5 is electrically connected to one terminal of resistor R14 and the corresponding terminal of error amplifier circuit 1. The third terminal of transistor Q5 is grounded. The other terminal of diode D1 is electrically connected to the corresponding terminal of MCU. The other terminal of resistor R10 is electrically connected to the other terminal of resistor R14. The corresponding terminal of error amplifier circuit 1 is also electrically connected to the corresponding terminal of MCU.

[0014] Preferably, the error amplifier circuit includes resistors R5, R6, R7, and R11, capacitors C1 and C2, and operational amplifier U3B. The positive terminal of operational amplifier U3B is electrically connected to the corresponding terminal of the MCU via resistor R5. The negative terminal of operational amplifier U3B is electrically connected to one end of resistors R6 and R7, and one end of capacitor C2. The output terminal of operational amplifier U3B is electrically connected to one end of capacitor C1, the other end of capacitor C2, and one end of resistor R11. The other end of resistor R11 is electrically connected to the second terminal of transistor Q5. The other end of capacitor C1 is electrically connected to the other end of resistor R7. The other end of resistor R6 is electrically connected to the other end of resistor R4.

[0015] Preferably, the second constant current charging control circuit includes resistor R15, resistor R16, transistor Q6, diode D2, and a second error amplifier circuit. The first terminal of transistor Q6 is electrically connected to one terminal of diode D2, the gate of field-effect transistor Q3, and one terminal of resistor R15. The second terminal of transistor Q6 is electrically connected to one terminal of resistor R16 and the corresponding terminal of the second error amplifier circuit. The third terminal of transistor Q6 is grounded. The other terminal of diode D2 is electrically connected to the corresponding terminal of the MCU. The other terminal of resistor R15 is electrically connected to the other terminal of resistor R16. The corresponding terminal of the second error amplifier circuit is also electrically connected to the corresponding terminal of the MCU.

[0016] Preferably, the second error amplifier circuit includes resistors R17, R19, R20, and R18, capacitors C3 and C4, and operational amplifier U2B. The positive terminal of operational amplifier U2B is electrically connected to the corresponding terminal of the MCU via resistor R17. The negative terminal of operational amplifier U2B is electrically connected to one end of resistors R19, R20, and capacitor C4. The output terminal of operational amplifier U2B is electrically connected to one end of capacitor C3, the other end of capacitor C4, and one end of resistor R18. The other end of resistor R18 is electrically connected to the second terminal of transistor Q6. The other end of capacitor C3 is electrically connected to the other end of resistor R20. The other end of resistor R19 is electrically connected to the other end of resistor R4.

[0017] The technical solution of this invention has the following advantages: By controlling the charging and discharging of the ceramic through a dual-loop current and voltage circuit, the rate of change of the charging and discharging of the ceramic tends to be constant. Compared with the traditional high-voltage operational amplifier ceramic drive, this circuit does not need to use expensive high-voltage operational amplifiers, thus reducing circuit costs. The dual-loop current and voltage control is used to drive the piezoelectric ceramic, realizing rapid control of the voltage across the piezoelectric ceramic. Due to the inverse piezoelectric effect, the ceramic deformation displacement changes rapidly, controlling the piezoelectric valve to spray glue at high speed. Attached Figure Description

[0018] Figure 1 This is the circuit diagram of the present invention. Detailed Implementation

[0019] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0020] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0021] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0022] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0023] In this invention, unless otherwise expressly specified and limited, the first feature is "on" or "on" the second feature.

[0024] The term "below" can include situations where the first and second features are in direct contact, or situations where the first and second features are in contact through another feature between them. Furthermore, "above," "over," and "on top" of the first feature above the second feature includes situations where the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" of the first feature below the second feature includes situations where the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0025] Reference Figure 1 The present invention provides a piezoelectric ceramic dual-loop drive circuit for a piezoelectric jet valve, comprising: a main control circuit 100, a charging switch circuit 300, a voltage sampling circuit 200, a current sampling circuit 400, a constant current charging control circuit one 500, and a constant current charging control circuit two 600.

[0026] The corresponding terminals of the main control circuit 100 are electrically connected to the corresponding terminals of the voltage sampling circuit 200, the charging switch circuit 300, the current sampling circuit 400, the constant current charging control circuit 1 500, and the constant current charging control circuit 2 600, respectively.

[0027] The corresponding terminals of the charging switch circuit 300 are also electrically connected to the corresponding terminals of the voltage sampling circuit 200, the current sampling circuit 400, the constant current charging control circuit 1 500, and the constant current charging control circuit 2 600, respectively; the constant current charging control circuit 1 500, the current sampling circuit 400, and the constant current charging control circuit 2 600 are arranged in parallel.

[0028] The charging switch circuit 300 includes field-effect transistors Q1, Q2, and Q3. When the piezoelectric ceramic is charging, field-effect transistor Q1 is closed, field-effect transistor Q2 is open, and field-effect transistor Q3 operates in the linear region to control the charging speed of Q3. When the piezoelectric ceramic is discharging, field-effect transistor Q1 is open, field-effect transistor Q2 operates in the linear region to control the discharging speed of field-effect transistor Q2, and field-effect transistor Q3 is closed. The main control circuit 100 is configured as an MCU.

[0029] Furthermore, the voltage sampling circuit 200 includes resistors R8 and R9, and operational amplifier UA2; the positive terminal of operational amplifier UA2 is electrically connected to one end of resistors R8 and R9 respectively, and the output terminal of operational amplifier UA2 is electrically connected to the negative terminal of operational amplifier UA2 and the corresponding terminal of MCU respectively; the other end of resistors R8 and R9 is electrically connected to the corresponding terminal of charging switch circuit 300 respectively.

[0030] Furthermore, the charging switch circuit 300 also includes a transistor Q4, a battery, resistors R12, R13, RS1, and a crystal oscillator Y1; the positive terminal of the battery is electrically connected to one end of resistor R12, the source of the field-effect transistor Q1, and the other end of resistor R8; the negative terminal of the battery is electrically connected to the corresponding terminal of the current sampling circuit, one end of resistor RS1, and the other end of resistor R9 and grounded; the other end of resistor R12 is electrically connected to the gate of the field-effect transistor Q1 and one end of resistor R13; the other end of resistor R13 is grounded through transistor Q4. The corresponding terminal of transistor Q4 is also electrically connected to the corresponding terminal of the MCU; the drain of transistor Q1 is electrically connected to the drain of transistor Q2 and one end of crystal Y1; the gate of transistor Q2 is electrically connected to the corresponding terminal of constant current charging control circuit 500; the source of transistor Q2 is electrically connected to the drain of transistor Q3 and the other end of crystal Y1; the gate of transistor Q3 is electrically connected to the corresponding terminal of constant current charging control circuit 600; and the source of transistor Q3 is electrically connected to the current sampling circuit 400 and the other end of resistor RS1.

[0031] Furthermore, the current sampling circuit 400 includes resistors R1, R2, R3, and R4, and operational amplifier U3A; the positive terminal of operational amplifier U3A is electrically connected to one end of resistors R3 and R1, respectively, and the negative terminal of operational amplifier U3A is electrically connected to one end of resistors R4 and R2, respectively; the other end of resistor R3 is grounded, and the other end of resistor R1 is electrically connected to the source of field-effect transistor Q3; the other end of resistor R4 is electrically connected to the output terminal of operational amplifier U3A, the corresponding terminal of constant current charging control circuit 500, the corresponding terminal of constant current charging control circuit 600, and the corresponding terminal of MCU, respectively; and the other end of resistor R2 is electrically connected to the negative terminal of the battery.

[0032] Furthermore, the constant current charging control circuit 500 includes resistors R10 and R14, transistor Q5, diode D1, and error amplifier circuit 1. The first terminal of transistor Q5 is electrically connected to one terminal of diode D1, the gate of field-effect transistor Q2, and one terminal of resistor R10. The second terminal of transistor Q5 is electrically connected to one terminal of resistor R14 and the corresponding terminal of error amplifier circuit 1. The third terminal of transistor Q5 is grounded. The other terminal of diode D1 is electrically connected to the corresponding terminal of MCU. The other terminal of resistor R10 is electrically connected to the other terminal of resistor R14. The corresponding terminal of error amplifier circuit 1 is also electrically connected to the corresponding terminal of MCU. The error amplifier circuit includes resistors R5, R6, R7, and R11, capacitors C1 and C2, and operational amplifier U3B. The positive terminal of operational amplifier U3B is electrically connected to the corresponding terminal of the MCU via resistor R5. The negative terminal of operational amplifier U3B is electrically connected to one end of resistors R6 and R7, and one end of capacitor C2. The output terminal of operational amplifier U3B is electrically connected to one end of capacitor C1, the other end of capacitor C2, and one end of resistor R11. The other end of resistor R11 is electrically connected to the second terminal of transistor Q5. The other end of capacitor C1 is electrically connected to the other end of resistor R7. The other end of resistor R6 is electrically connected to the other end of resistor R4.

[0033] Furthermore, the constant current charging control circuit 600 includes resistors R15 and R16, transistor Q6, diode D2, and error amplifier circuit 2. The first terminal of transistor Q6 is electrically connected to one terminal of diode D2, the gate of field-effect transistor Q3, and one terminal of resistor R15. The second terminal of transistor Q6 is electrically connected to one terminal of resistor R16 and the corresponding terminal of error amplifier circuit 2. The third terminal of transistor Q6 is grounded. The other terminal of diode D2 is electrically connected to the corresponding terminal of MCU. The other terminal of resistor R15 is electrically connected to the other terminal of resistor R16. The corresponding terminal of error amplifier circuit 2 is also electrically connected to the corresponding terminal of MCU. The second error amplifier circuit includes resistors R17, R19, R20, and R18, capacitors C3 and C4, and operational amplifier U2B. The positive terminal of operational amplifier U2B is electrically connected to the corresponding terminal of the MCU via resistor R17. The negative terminal of operational amplifier U2B is electrically connected to one end of resistors R19 and R20, and one end of capacitor C4. The output terminal of operational amplifier U2B is electrically connected to one end of capacitor C3, the other end of capacitor C4, and one end of resistor R18. The other end of resistor R18 is electrically connected to the second terminal of transistor Q6. The other end of capacitor C3 is electrically connected to the other end of resistor R20. The other end of resistor R19 is electrically connected to the other end of resistor R4.

[0034] The working principle of this invention is as follows:

[0035] a. This circuit has three power MOSFETs Q1, Q2, and Q3: When the piezoelectric ceramic is charging, MOSFET Q1 is closed, MOSFET Q2 is open, and MOSFET Q3 operates in the linear region to control the charging speed of Q3; when the piezoelectric ceramic is discharging, MOSFET Q1 is open, MOSFET Q2 operates in the linear region to control the discharging speed of MOSFET Q2, and MOSFET Q3 is closed.

[0036] b. The charging and discharging currents of the piezoelectric ceramic will flow through resistor RS1 and be converted into voltages corresponding to the currents. These voltages are sampled by resistors R1, R2, R3, and R4 of the current sampling circuit 400 and operational amplifier U3A, and then output to the MCU to participate in the control of ceramic charging and discharging.

[0037] c. Charging circuit: When the ceramic is charging, the MCU controls the field-effect transistor Q1 to close via CTRL-3 and controls the field-effect transistor Q2 to open via CTRL-1; the MCU samples the ceramic voltage through resistors R8 and R9 of the voltage sampling circuit 200 and operational amplifier U2A, and sets the charging current setpoint IREF-2 by calculating and comparing the ceramic change rate with the set value inside the MCU; IREF-2 and the actual current I-ADC control the charging current through the circuit related to operational amplifier U2A.

[0038] d. Discharge Circuit: During ceramic discharge, the MCU controls the MOSFET Q1 to disconnect via CTRL-3 and controls the MOSFET Q2 to disconnect via CTRL-1. The MCU samples the ceramic voltage through resistors R8 and R9 of the voltage sampling circuit 200 and operational amplifier U2A. Internally, the MCU calculates and compares the ceramic voltage change rate with the set value to set the discharge current setpoint IREF-1. IREF-1 and the actual current I-ADC control the ceramic discharge current through the circuitry related to operational amplifier U2A.

[0039] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A piezoelectric ceramic dual-loop drive circuit for a piezoelectric injection valve, characterized in that, include: Main control circuit, charging switch circuit, voltage sampling circuit, current sampling circuit, constant current charging control circuit one, constant current charging control circuit two; The corresponding terminals of the main control circuit are electrically connected to the corresponding terminals of the voltage sampling circuit, the charging switch circuit, the current sampling circuit, the constant current charging control circuit one, and the constant current charging control circuit two, respectively. The corresponding terminals of the charging switch circuit are also electrically connected to the corresponding terminals of the voltage sampling circuit, the current sampling circuit, the constant current charging control circuit one, and the constant current charging control circuit two, respectively; the constant current charging control circuit one, the current sampling circuit, and the constant current charging control circuit two are arranged in parallel. The charging switch circuit includes field-effect transistors Q1, Q2, and Q3. When the piezoelectric ceramic is charging, field-effect transistor Q1 is closed, field-effect transistor Q2 is open, and field-effect transistor Q3 operates in the linear region to control the charging speed of Q3. When the piezoelectric ceramic is discharging, field-effect transistor Q1 is open, field-effect transistor Q2 operates in the linear region to control the discharging speed of field-effect transistor Q2, and field-effect transistor Q3 is closed.

2. The piezoelectric ceramic dual-loop drive circuit for the piezoelectric injection valve according to claim 1, characterized in that, The main control circuit is set as an MCU.

3. The piezoelectric ceramic dual-loop drive circuit for the piezoelectric injection valve according to claim 2, characterized in that, The voltage sampling circuit includes resistors R8 and R9, and operational amplifier UA2. The positive terminal of operational amplifier UA2 is electrically connected to one end of resistors R8 and R9, and the output terminal of operational amplifier UA2 is electrically connected to the negative terminal of operational amplifier UA2 and the corresponding terminal of the MCU. The other ends of resistors R8 and R9 are electrically connected to the corresponding terminals of the charging switch circuit.

4. The piezoelectric ceramic dual-loop drive circuit for the piezoelectric injection valve according to claim 3, characterized in that, The charging switch circuit also includes a transistor Q4, a battery, resistors R12, R13, RS1, and a crystal oscillator Y1. The positive terminal of the battery is electrically connected to one end of resistor R12, the source of the field-effect transistor Q1, and the other end of resistor R8. The negative terminal of the battery is electrically connected to the corresponding terminal of the current sampling circuit, one end of resistor RS1, and the other end of resistor R9, and grounded. The other end of resistor R12 is electrically connected to the gate of the field-effect transistor Q1 and one end of resistor R13. The other end of resistor R13 is grounded through transistor Q4. The corresponding terminal of transistor Q4 is also electrically connected to the corresponding terminal of the MCU; the drain of the field-effect transistor Q1 is electrically connected to the drain of the field-effect transistor Q2 and one end of the crystal Y1; the gate of the field-effect transistor Q2 is electrically connected to the corresponding terminal of the constant current charging control circuit; the source of the field-effect transistor Q2 is electrically connected to the drain of the field-effect transistor Q3 and the other end of the crystal Y1; the gate of the field-effect transistor Q3 is electrically connected to the corresponding terminal of the constant current charging control circuit; and the source of the field-effect transistor Q3 is electrically connected to the current sampling circuit and the other end of the resistor RS1.

5. The piezoelectric ceramic dual-loop drive circuit for the piezoelectric injection valve according to claim 4, characterized in that, The current sampling circuit includes resistors R1, R2, R3, and R4, and operational amplifier U3A. The positive terminal of operational amplifier U3A is electrically connected to one end of resistors R3 and R1, and the negative terminal of operational amplifier U3A is electrically connected to one end of resistors R4 and R2. The other end of resistor R3 is grounded, and the other end of resistor R1 is electrically connected to the source of field-effect transistor Q3. The other end of resistor R4 is electrically connected to the output terminal of operational amplifier U3A, the corresponding terminal of constant current charging control circuit one, the corresponding terminal of constant current charging control circuit two, and the corresponding terminal of MCU. The other end of resistor R2 is electrically connected to the negative terminal of the battery.

6. The piezoelectric ceramic dual-loop drive circuit for the piezoelectric injection valve according to claim 5, characterized in that, The constant current charging control circuit includes resistors R10 and R14, transistor Q5, diode D1, and error amplifier circuit 1. The first terminal of transistor Q5 is electrically connected to one terminal of diode D1, the gate of field-effect transistor Q2, and one terminal of resistor R10. The second terminal of transistor Q5 is electrically connected to one terminal of resistor R14 and the corresponding terminal of error amplifier circuit 1. The third terminal of transistor Q5 is grounded. The other terminal of diode D1 is electrically connected to the corresponding terminal of the MCU. The other terminal of resistor R10 is electrically connected to the other terminal of resistor R14. The corresponding terminal of error amplifier circuit 1 is also electrically connected to the corresponding terminal of the MCU.

7. The piezoelectric ceramic dual-loop drive circuit for the piezoelectric injection valve according to claim 6, characterized in that, The error amplifier circuit includes resistors R5, R6, R7, and R11, capacitors C1 and C2, and operational amplifier U3B. The positive terminal of operational amplifier U3B is electrically connected to the corresponding terminal of the MCU via resistor R5. The negative terminal of operational amplifier U3B is electrically connected to one end of resistors R6 and R7, and one end of capacitor C2. The output terminal of operational amplifier U3B is electrically connected to one end of capacitor C1, the other end of capacitor C2, and one end of resistor R11. The other end of resistor R11 is electrically connected to the second terminal of transistor Q5. The other end of capacitor C1 is electrically connected to the other end of resistor R7. The other end of resistor R6 is electrically connected to the other end of resistor R4.

8. The piezoelectric ceramic dual-loop drive circuit for the piezoelectric injection valve according to claim 7, characterized in that, The second constant current charging control circuit includes resistors R15 and R16, transistor Q6, diode D2, and a second error amplifier circuit. The first terminal of transistor Q6 is electrically connected to one end of diode D2, the gate of field-effect transistor Q3, and one end of resistor R15. The second terminal of transistor Q6 is electrically connected to one end of resistor R16 and the corresponding terminal of the second error amplifier circuit. The third terminal of transistor Q6 is grounded. The other end of diode D2 is electrically connected to the corresponding terminal of the MCU. The other end of resistor R15 is electrically connected to the other end of resistor R16. The corresponding terminal of the second error amplifier circuit is also electrically connected to the corresponding terminal of the MCU.

9. The piezoelectric ceramic dual-loop drive circuit for the piezoelectric injection valve according to claim 8, characterized in that, The second error amplifier circuit includes resistors R17, R19, R20, and R18, capacitors C3 and C4, and operational amplifier U2B. The positive terminal of operational amplifier U2B is electrically connected to the corresponding terminal of the MCU via resistor R17. The negative terminal of operational amplifier U2B is electrically connected to one end of resistors R19 and R20, and one end of capacitor C4. The output terminal of operational amplifier U2B is electrically connected to one end of capacitor C3, the other end of capacitor C4, and one end of resistor R18. The other end of resistor R18 is electrically connected to the second terminal of transistor Q6. The other end of capacitor C3 is electrically connected to the other end of resistor R20. The other end of resistor R19 is electrically connected to the other end of resistor R4.

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