阅读说明：本技术 高压静电喷涂控制系统及控制方法 (High-voltage electrostatic spraying control system and control method ) 是由 熊文 姚路 徐雪强 邓庆 唐剑 于 2020-07-14 设计创作，主要内容包括：本发明公开了高压静电喷涂控制系统及控制方法,涉及静电粉末喷涂控制技术领域,该高压静电喷涂控制系统包括主控单元、高压推动单元、外部触发信号产生单元、喷枪接口信号处理单元与气压信号处理单元。该高压静电喷涂控制方法包括以下步骤：产生外部触发信号并发送至所述高压推动单元；将外部开关触发信号进行光耦隔离并发送至主控单元,根据反馈信号生成电路开关信号与气路开关信号；主控单元接收开关触发信号并生成反馈信号以及PWM和DAC信号；喷枪接口信号处理单元接收电路开关信号,控制电压输出；气压信号处理单元接收气路开关信号。本发明,实现静电电压、静电电流、流速气压和雾化气压四个变量的自动控制。(The invention discloses a high-voltage electrostatic spraying control system and a control method, and relates to the technical field of electrostatic powder spraying control. The high-voltage electrostatic spraying control method comprises the following steps: generating an external trigger signal and sending the external trigger signal to the high-voltage pushing unit; performing optical coupling isolation on an external switch trigger signal, sending the external switch trigger signal to a main control unit, and generating a circuit switching signal and a gas circuit switching signal according to a feedback signal; the main control unit receives the switch trigger signal and generates a feedback signal, a PWM signal and a DAC signal; the spray gun interface signal processing unit receives a circuit switching signal and controls voltage output; the air pressure signal processing unit receives an air channel switching signal. The invention realizes the automatic control of four variables of electrostatic voltage, electrostatic current, flow velocity air pressure and atomization air pressure.)

1. The high-voltage electrostatic spraying control system is characterized by comprising a main control unit, a high-voltage pushing unit, an external trigger signal generating unit, a spray gun interface signal processing unit and an air pressure signal processing unit;

the external trigger signal generating unit is connected with the high-voltage pushing unit and used for generating an external trigger signal and sending the external trigger signal to the high-voltage pushing unit;

the high-voltage pushing unit is connected with the main control unit and used for carrying out optical coupling isolation on an external switch trigger signal and sending the external switch trigger signal to the main control unit, generating a gas circuit switching signal and a circuit switching signal according to a feedback signal of the main control unit, and meanwhile, the high-voltage pushing unit receives PWM (pulse width modulation) and DAC (digital-to-analog converter) signals output by the main control unit and pushes a high-voltage pack module in the spray gun to generate high-voltage static electricity;

the main control unit is used for receiving the switch trigger signal processed by the high-voltage pushing unit, generating a feedback signal, a PWM (pulse-width modulation) signal and a DAC (digital-to-analog converter) signal according to set parameters, sending the generated feedback signal, the PWM signal and the DAC signal to the high-voltage pushing unit, collecting a current signal amplified and conditioned by the spray gun interface signal processing unit, forming a closed-loop system by adopting a PID (proportion integration differentiation) algorithm, stabilizing the voltage by constant current, and ensuring the stability of high-voltage static electricity;

the spray gun interface signal processing unit is connected with the high-voltage pushing unit and the main control unit and used for receiving circuit switching signals, controlling voltage output, processing current signals fed back by high-voltage static electricity to the ground, amplifying and conditioning the current signals to the main control unit for collection;

the air pressure signal processing unit is connected with the high-pressure pushing unit and the main control unit and used for receiving an air channel switching signal and feeding back the acquired analog quantity after signal processing to the main control unit, so that the main control unit controls spraying fluidization air pressure and atomization air pressure through algorithm operation PI, and a closed-loop system is formed.

2. The system of claim 1, wherein the high voltage boost unit comprises: the trigger circuit comprises a first drive circuit, a second drive circuit and a trigger signal processing circuit;

the trigger signal processing circuit is connected with the first driving circuit and used for transmitting an external trigger signal to the main control unit after optically coupling and uncoupling, receiving a feedback signal of the main control unit and generating an air circuit switching signal and a circuit switching signal according to the feedback signal;

the first driving circuit is connected with the second driving circuit and used for pushing a high-voltage pack module in the spray gun to generate high-voltage static electricity according to PWM and DAC signals output by the main control unit;

the second driving circuit is connected with the trigger signal processing circuit and is used for being matched with the first driving circuit to push the high-voltage pack module in the spray gun.

3. The high-voltage electrostatic painting control system of claim 2, wherein: the first driving circuit comprises a driver U, a resistor R, a diode D, a diode Q, a capacitor C, a capacitor E, an inductor L, an MOS tube U and a voltage stabilizing tube U4, wherein the resistor R, the capacitor C, the diode D and the inductor L are all connected with the driver U, the MOS tube U is connected with the resistor R, the diode D is connected with the MOS tube U, the diode D is connected with the diode D, the inductor L is connected with the resistor R and the capacitor E, the resistor R is connected with the resistor R, and the resistor R is connected with the voltage stabilizing tube U4, the voltage regulator tube U4D is connected with a resistor R86, and a resistor R86 is connected with a diode Q5 and a capacitor C8.

4. The high-voltage electrostatic painting control system of claim 2, wherein: the second driving circuit comprises a driver U7, a resistor R1, a resistor R2, a resistor R3, a resistor R5, a resistor R90, a resistor R91, a resistor R94, a resistor R97, a resistor R101, a resistor R102, a resistor R103, a resistor R104, a resistor R105, a resistor R106, a diode D21, a diode D3, a diode D9, a diode Q6, a capacitor C10, a capacitor CE6, a MOS tube U9, a MOS tube U10 and a voltage regulator tube U4B, wherein the resistor R101, the resistor R102, the resistor R103, the resistor R104, the resistor R105, the resistor R106, the diode D21, the capacitor C10 and the capacitor CE6 are all connected with the driver U7, the resistor R102 is connected with the MOS tube U9, the resistor R101 is connected with the MOS tube U10, the resistor R10, the diode D10 and the CE 72 are connected between the resistor R10 and the capacitor CE 72, the resistor R10 and the CE 72 are connected with the voltage regulator tube U10 in parallel with the resistor R10, the resistor R90, the resistor R91, the resistor R94 and the resistor R97 are all connected with a voltage regulator tube U4B, and the diode Q6 is connected with a voltage regulator tube U4B.

5. The high-voltage electrostatic painting control system of claim 2, wherein: the trigger signal processing circuit comprises an amplifier U, a resistor R, a voltage regulator tube U12, a capacitor C, a diode D and a diode Q, wherein the resistor R, the diode D and the voltage regulator tube U12 are respectively connected with the amplifier U, the resistor R and the capacitor C are connected with the voltage regulator tube U12, the capacitor C is connected with the resistor R, the voltage regulator tube U12 are connected in series, the diode D and the voltage regulator tube U12 are connected between the resistor R and the resistor R, the resistor R and the resistor R are connected with the voltage regulator tube U, The resistor R71 is connected in series between the resistor R69 and the capacitor C15, the resistor R68 and the capacitor C16 are both connected with the resistor R69, the voltage regulator tube U12C is connected with the resistor R68, the resistor R63, the resistor R67 and the capacitor C17 are both connected with the voltage regulator tube U12C, and the capacitor C21 and the diode Q3 are both connected with the resistor R63.

6. The high-voltage electrostatic spraying control system according to claim 1, wherein: the master control unit comprises a master control chip and a sampling circuit, a crystal oscillator circuit and a memory which are connected with the master control chip, wherein the model of the master control chip is STM32F103ZET 6.

7. The high-voltage electrostatic spraying control system according to claim 1, wherein: the air pressure signal processing unit comprises a first electromagnetic valve control circuit, a second electromagnetic valve control circuit, a third electromagnetic valve control circuit and a fourth electromagnetic valve control circuit, wherein the four electromagnetic valve control circuits respectively comprise a control chip, and the model of the chip is L6219 DS.

8. The high-voltage electrostatic spraying control method is characterized by comprising the following steps of:

an external trigger signal is generated by an external trigger signal generating unit and is sent to a high-voltage pushing unit;

the external switch trigger signal is optically coupled and isolated through the high-voltage pushing unit and is sent to the main control unit, a gas circuit switching signal and a circuit switching signal are generated according to a feedback signal of the main control unit, and meanwhile, PWM and DAC signals output by the main control unit are received, and a high-voltage bag module in the spray gun is pushed to generate high-voltage static electricity;

the spray gun interface signal processing unit receives a circuit switching signal, controls voltage output, simultaneously processes a current signal fed back by high-voltage static earth, amplifies and conditions the current signal and sends the amplified current signal to the main control unit for collection;

the air pressure signal processing unit receives an air channel switching signal and feeds back the acquired analog quantity after signal processing to the main control unit, so that the main control unit controls spraying fluidization air pressure and atomization air pressure through algorithm operation PI, and a closed-loop system is formed;

the main control unit receives the switch trigger signal processed by the high-voltage pushing unit, generates a feedback signal, a PWM (pulse width modulation) signal and a DAC (digital-to-analog converter) signal according to set parameters, sends the generated feedback signal, the PWM signal and the DAC signal to the high-voltage pushing unit, collects a current signal amplified and conditioned by the spray gun interface signal processing unit, forms a closed-loop system by adopting a PID (proportion integration differentiation) algorithm, and is constant in current and stable in voltage, so that high-voltage static stability is ensured.

9. The high-voltage electrostatic spraying control method according to claim 8, characterized in that: the gas circuit switching signal and the circuit switching signal are generated by a trigger signal processing circuit of the high-voltage pushing unit.

10. The high-voltage electrostatic spraying control method according to claim 8, characterized in that: the main control unit controls the electromagnetic valve control circuit through algorithm operation PI so as to control the spraying fluidization air pressure and the atomization air pressure.

Technical Field

The invention relates to the technical field of electrostatic powder spraying control, in particular to a high-voltage electrostatic spraying control system and a control method.

Background

Because the electrostatic spraying operation is applied to the powder spraying, the coating equipment can almost be fully automated, and the human resources are saved. Even if manual assistance is needed, the painting personnel can master the operation skills without long-term training. The powder coating is 100% solid content, and no solvent is needed, so the coating amount is reduced, the package is saved, and the storage space is reduced.

The powder coating avoids the waste caused by volatilization to the atmosphere because no organic volatile matters are generated, so that the energy cost is greatly reduced compared with the liquid coating. The thick film can be obtained by one-time spraying of the electrostatic spraying equipment, repeated spraying is not needed, priming is not needed, and the coating operation speed is higher and the efficiency is higher than that of the coating operation with the same film thickness. The coating equipment does not need rest time, so that the equipment space can be saved. In addition, the baking time of powder spraying is shorter than that of liquid spraying, so that the consumption of fuel energy can be greatly reduced, the coating operation line is shortened, and the yield and the production efficiency are improved.

Spraying powder coating on the surface of a workpiece by using electrostatic powder spraying equipment, wherein the powder is uniformly adsorbed on the surface of the workpiece under the electrostatic action to form a powdery coating; the powdery coating is baked, leveled and solidified at high temperature to become final coatings with different effects.

However, the existing electrostatic powder spraying control technology has some defects, the fluidization air pressure and the atomization air pressure cannot be effectively controlled, and the spraying effect is not ideal enough.

Therefore, a high-voltage electrostatic spraying control system and a control method are provided.

Disclosure of Invention

The invention aims to provide a high-voltage electrostatic spraying control system and a control method, which realize automatic control of four variables of electrostatic voltage, electrostatic current, flow velocity air pressure and atomization air pressure, provide a plurality of control modes, introduce a learning control strategy into electrostatic spraying control, realize high-quality spraying on curved surfaces of complex workpieces and solve the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme: the high-voltage electrostatic spraying control system is characterized by comprising a main control unit, a high-voltage pushing unit, an external trigger signal generating unit, a spray gun interface signal processing unit and an air pressure signal processing unit;

the external trigger signal generating unit is connected with the high-voltage pushing unit and used for generating an external trigger signal and sending the external trigger signal to the high-voltage pushing unit;

the high-voltage pushing unit is connected with the main control unit and used for carrying out optical coupling isolation on an external switch trigger signal and sending the external switch trigger signal to the main control unit, generating a gas circuit switching signal and a circuit switching signal according to a feedback signal of the main control unit, and meanwhile, the high-voltage pushing unit receives PWM (pulse width modulation) and DAC (digital-to-analog converter) signals output by the main control unit and pushes a high-voltage pack module in the spray gun to generate high-voltage static electricity;

the main control unit is used for receiving the switch trigger signal processed by the high-voltage pushing unit, generating a feedback signal, a PWM (pulse-width modulation) signal and a DAC (digital-to-analog converter) signal according to set parameters, sending the generated feedback signal, the PWM signal and the DAC signal to the high-voltage pushing unit, collecting a current signal amplified and conditioned by the spray gun interface signal processing unit, forming a closed-loop system by adopting a PID (proportion integration differentiation) algorithm, stabilizing the voltage by constant current, and ensuring the stability of high-voltage static electricity;

the spray gun interface signal processing unit is connected with the high-voltage pushing unit and the main control unit and used for receiving circuit switching signals, controlling voltage output, processing current signals fed back by high-voltage static electricity to the ground, amplifying and conditioning the current signals to the main control unit for collection;

the air pressure signal processing unit is connected with the high-pressure pushing unit and the main control unit and used for receiving an air channel switching signal and feeding back the acquired analog quantity after signal processing to the main control unit, so that the main control unit controls spraying fluidization air pressure and atomization air pressure through algorithm operation PI, and a closed-loop system is formed.

Preferably, the high pressure push unit includes: the trigger circuit comprises a first drive circuit, a second drive circuit and a trigger signal processing circuit;

the trigger signal processing circuit is connected with the first driving circuit and used for transmitting an external trigger signal to the main control unit after optically coupling and uncoupling, receiving a feedback signal of the main control unit and generating an air circuit switching signal and a circuit switching signal according to the feedback signal;

the first driving circuit is connected with the second driving circuit and used for pushing a high-voltage pack module in the spray gun to generate high-voltage static electricity according to PWM and DAC signals output by the main control unit;

the second driving circuit is connected with the trigger signal processing circuit and is used for being matched with the first driving circuit to push the high-voltage pack module in the spray gun.

Preferably, the first driving circuit comprises a driver U, a resistor R, a diode D, a diode Q, a capacitor C, a capacitor E, an inductor L, an MOS tube U and a voltage regulator tube U4, wherein the resistor R, the capacitor C, the diode D and the inductor L are all connected with the driver U, the MOS tube U is connected with the resistor R, the diode D is connected with the MOS tube U, the diode D is connected with the diode D, the inductor L is connected with the resistor R and the capacitor E, the resistor R is connected with the resistor R, and the resistor R is connected with the voltage regulator tube U4, the voltage regulator tube U4D is connected with a resistor R86, and a resistor R86 is connected with a diode Q5 and a capacitor C8.

Preferably, the second driving circuit comprises a driver U7, a resistor R1, a resistor R2, a resistor R3, a resistor R5, a resistor R90, a resistor R91, a resistor R94, a resistor R97, a resistor R101, a resistor R102, a resistor R103, a resistor R104, a resistor R105, a resistor R106, a diode D21, a diode D3, a diode D9, a diode Q6, a capacitor C10, a capacitor CE6, a MOS tube U9, a MOS tube U10, a regulator U4B, wherein the resistor R101, the resistor R102, the resistor R103, the resistor R104, the resistor R105, the resistor R106, a diode D21, a capacitor C10, and a capacitor C6 are all connected with the driver U7, the resistor R102 is connected with the MOS tube U9, the resistor R101 is connected with the MOS tube U10, the resistor R10, the diode D10, the capacitor CE 72, the resistor R10, the resistor R72, the resistor R10, the capacitor CE, the resistor R72, the regulator U10, the capacitor CE, the resistor R72, the resistor R, the resistor R90, the resistor R91, the resistor R94 and the resistor R97 are all connected with a voltage regulator tube U4B, and the diode Q6 is connected with a voltage regulator tube U4B.

Preferably, the trigger signal processing circuit comprises an amplifier U11, a resistor R61, a voltage regulator U12 61, a capacitor C61, a diode D61, and a diode Q61, wherein the resistor R61, the diode D61, the voltage regulator U12 61 are respectively connected with the amplifier U61, the resistor R61, the capacitor C61 and the voltage regulator U12 61, the resistor R61, the voltage regulator U12 and the resistor R61 are connected in series with the voltage regulator U61, the voltage regulator R61, the resistor R61 and the voltage regulator U61 are connected in series, the voltage regulator 61, The resistor R70 and the resistor R71 are connected in series between the resistor R69 and the capacitor C15, the resistor R68 and the capacitor C16 are both connected with the resistor R69, the voltage-stabilizing tube U12C is connected with the resistor R68, the resistor R63, the resistor R67 and the capacitor C17 are both connected with the voltage-stabilizing tube U12C, and the capacitor C21 and the diode Q3 are both connected with the resistor R63.

Preferably, the main control unit includes the main control chip and the sampling circuit, the crystal oscillator circuit and the memory that are connected with it, the model of main control chip is STM32F103ZET 6.

Preferably, the air pressure signal processing unit includes a first solenoid valve control circuit, a second solenoid valve control circuit, a third solenoid valve control circuit, and a fourth solenoid valve control circuit, and each of the four solenoid valve control circuits includes a control chip, and the model of the chip is L6219 DS.

The high-voltage electrostatic spraying control method comprises the following steps:

an external trigger signal is generated by an external trigger signal generating unit and is sent to a high-voltage pushing unit;

the external switch trigger signal is optically coupled and isolated through the high-voltage pushing unit and is sent to the main control unit, a gas circuit switching signal and a circuit switching signal are generated according to a feedback signal of the main control unit, and meanwhile, PWM and DAC signals output by the main control unit are received, and a high-voltage bag module in the spray gun is pushed to generate high-voltage static electricity;

the spray gun interface signal processing unit receives a circuit switching signal, controls voltage output, simultaneously processes a current signal fed back by high-voltage static earth, amplifies and conditions the current signal and sends the amplified current signal to the main control unit for collection;

the air pressure signal processing unit receives an air channel switching signal and feeds back the acquired analog quantity after signal processing to the main control unit, so that the main control unit controls spraying fluidization air pressure and atomization air pressure through algorithm operation PI, and a closed-loop system is formed;

the main control unit receives the switch trigger signal processed by the high-voltage pushing unit, generates a feedback signal, a PWM (pulse width modulation) signal and a DAC (digital-to-analog converter) signal according to set parameters, sends the generated feedback signal, the PWM signal and the DAC signal to the high-voltage pushing unit, collects a current signal amplified and conditioned by the spray gun interface signal processing unit, forms a closed-loop system by adopting a PID (proportion integration differentiation) algorithm, and is constant in current and stable in voltage, so that high-voltage static stability is ensured.

Preferably, the air circuit switching signal and the circuit switching signal are generated by a trigger signal processing circuit of the high-voltage pushing unit.

Preferably, the main control unit controls the electromagnetic valve control circuit through algorithm operation PI so as to control spraying fluidization air pressure and atomization air pressure.

Compared with the prior art, the invention has the beneficial effects that:

1. the automatic control of four variables of electrostatic voltage, electrostatic current, flow velocity air pressure and atomization air pressure is realized, a plurality of control modes are provided, and a learning control strategy is introduced into the electrostatic spraying control, so that the high-quality spraying of the curved surface of the complex workpiece is realized.

2. The performance of the paint is obviously superior to that of the traditional spraying equipment through the test of various environments. The intelligent degree is high, and no danger exists; the pollution is effectively reduced, the materials are greatly saved, and the labor cost is greatly reduced.

Drawings

FIG. 1 is a block diagram of the present invention;

FIG. 2 is a circuit diagram of a master control unit according to the present invention;

FIG. 3 is a circuit diagram b of the master control unit according to the present invention;

FIG. 4 is a circuit diagram of a master control unit c according to the present invention

FIG. 5 is a circuit diagram d of the master control unit of the present invention;

FIG. 6 is a circuit diagram e of the master control unit according to the present invention;

FIG. 7 is a circuit diagram a of the pneumatic signal processing unit according to the present invention;

FIG. 8 is a circuit diagram b of the pneumatic signal processing unit according to the present invention;

FIG. 9 is a first driving circuit diagram of the high voltage driving unit of the present invention;

FIG. 10 is a second driving circuit diagram of the high voltage driving unit of the present invention;

FIG. 11 is a circuit diagram of a trigger signal processing circuit of the high voltage driving unit according to the present invention;

FIG. 12 is a circuit diagram of the human-computer interaction unit of the present invention;

FIG. 13 is a circuit diagram b of the human-computer interaction unit according to the present invention;

FIG. 14 is a circuit diagram c of the human-computer interaction unit according to the present invention;

FIG. 15 is a spray gun interface signal processing unit a of the present invention;

FIG. 16 is a spray gun interface signal processing unit b of the present invention;

FIG. 17 is a spray gun interface signal processing unit c of the present invention;

fig. 18 shows a signal processing unit d of the torch interface according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1 to 18, the present invention provides a technical solution:

a high-voltage electrostatic spraying control system comprises a main control unit, a high-voltage pushing unit, an external trigger signal generating unit, a spray gun interface signal processing unit, an air pressure signal processing unit, a man-machine interaction unit connected with the main control unit and a power circuit for supplying power to the man-machine interaction unit and the air pressure signal processing unit, as shown in figure 1.

As shown in fig. 1, the external trigger signal generating unit is connected to the high voltage pushing unit for generating an external trigger signal and sending the external trigger signal to the high voltage pushing unit.

As shown in fig. 9 to 11, the high voltage pushing unit is connected to the main control unit, and is configured to optically couple and isolate the external switch trigger signal and send the external switch trigger signal to the main control unit, and generate the air circuit switching signal and the circuit switching signal according to the feedback signal of the main control unit. Meanwhile, the high-voltage pushing unit receives PWM and DAC signals output by the main control unit and pushes a high-voltage pack module in the spray gun to generate high-voltage static electricity. The high pressure push unit includes: the circuit comprises a first driving circuit, a second driving circuit and a trigger signal processing circuit. The trigger signal processing circuit is connected with the first driving circuit and used for transmitting an external trigger signal to the main control unit after optically coupling and uncoupling and receiving a feedback signal of the main control unit and generating an air circuit switching signal and a circuit switching signal according to the feedback signal. The first driving circuit is connected with the second driving circuit and used for pushing a high-voltage pack module in the spray gun to generate high-voltage static electricity according to PWM and DAC signals output by the main control unit. The second driving circuit is connected with the trigger signal processing circuit and is used for being matched with the first driving circuit to push the high-voltage pack module in the spray gun.

As shown in fig. 2 to 6, the main control unit is configured to receive the switch trigger signal processed by the high voltage driving unit, generate a feedback signal and PWM and DAC signals according to the set parameters, and send the generated feedback signal and PWM and DAC signals to the high voltage driving unit. Meanwhile, the main control unit collects current signals amplified and conditioned by the spray gun interface signal processing unit, and a closed-loop system is formed by adopting a PID algorithm, so that constant current and voltage are stabilized, and high-voltage static stability is ensured. The main control unit comprises a main control chip and a sampling circuit, a crystal oscillator circuit and a memory which are connected with the main control chip, wherein the model of the main control chip is STM32F103ZET 6.

As shown in fig. 15 to 18, the spray gun interface signal processing unit is connected to the high voltage pushing unit and the main control unit, and is configured to receive a circuit switching signal and control voltage output. And meanwhile, current signals fed back from the high-voltage static earth are processed and amplified and conditioned to be collected by the main control unit.

As shown in fig. 7 and 8, the air pressure signal processing unit is connected to the high pressure pushing unit and the main control unit, and is configured to receive an air path switching signal and feed back an analog quantity acquired after signal processing to the main control unit, so that the main control unit controls the spraying fluidization air pressure and the atomization air pressure through algorithm operation PI, thereby forming a closed-loop system. The air pressure signal processing unit comprises a first electromagnetic valve control circuit, a second electromagnetic valve control circuit, a third electromagnetic valve control circuit and a fourth electromagnetic valve control circuit, wherein the four electromagnetic valve control circuits respectively comprise a control chip, and the model of the chip is L6219 DS.

As shown in fig. 12 to 14, the human-computer interaction unit includes an LCD liquid crystal display circuit and a plurality of operation key circuits. The operation key circuit adopts an optical coupling isolation technology, so that the stability of key input is ensured and system parameters are set. The LCD circuit is communicated with the main control chip in an RS422 communication mode, data are sent to the LED nixie tube according to a protocol for display, and meanwhile, the LCD circuit has a multi-machine communication function and can send the data to the background monitoring platform through RS485 interface communication.

The electrostatic spraying control system realizes automatic control of four variables of electrostatic voltage, electrostatic current, flow velocity and air pressure and atomization air pressure, provides multiple control modes, introduces a learning control strategy into electrostatic spraying control, and realizes high-quality spraying of the curved surface of a complex workpiece.

As shown in fig. 9, the first driving circuit includes a driver U3, a resistor R76, a resistor R77, a resistor R78, a resistor R79, a resistor R80, a resistor R81, a resistor R82, a resistor R83, a resistor R84, a resistor R85, a resistor R86, a diode D1, a diode D2, a diode D24, a diode Q5, a capacitor C1, a capacitor C8, a capacitor E8, an inductor L1, a MOS transistor U1, a MOS transistor U2, and a regulator U4D. The resistor R76, the resistor R77, the resistor R78, the resistor R79, the resistor R80, the resistor R81, the capacitor C1, the diode D24 and the inductor L1 are all connected with the driver U3, the MOS tube U1 is connected with the resistor R76, and the MOS tube U2 is connected with the resistor R77. Diode D2 is connected to MOS transistor U1, diode D1 is connected to diode D2, inductor L1 is connected to resistor R82 and capacitor E8, and resistor R82 is connected to resistor R83. The resistor R83 is connected with the resistor R84 and the resistor R85, the resistor R85 is connected with the voltage regulator tube U4D, the voltage regulator tube U4D is connected with the resistor R86, and the resistor R86 is connected with the diode Q5 and the capacitor C8.

As shown in fig. 10, the second driving circuit includes a driver U7, a resistor R1, a resistor R2, a resistor R3, a resistor R5, a resistor R90, a resistor R91, a resistor R94, a resistor R97, a resistor R101, a resistor R102, a resistor R103, a resistor R104, a resistor R105, a resistor R106, a diode D21, a diode D3, a diode D9, a diode Q6, a capacitor C10, a capacitor CE6, a MOS transistor U9, a MOS transistor U10, and a regulator U4B. The resistor R101, the resistor R102, the resistor R103, the resistor R104, the resistor R105, the resistor R106, the diode D21, the capacitor C10 and the capacitor CE6 are all connected with the driver U7, and the resistor R102 is connected with the MOS transistor U9. The resistor R101 is connected to the MOS transistor U10, and the resistor R5 and the diode D3 are connected between the capacitor CE6 and the driver U7. The diode D9 is connected between the resistor R5 and the capacitor CE6, the capacitor CE6 is connected with the voltage regulator tube U4B, and the resistor R1, the resistor R2 and the resistor R3 are connected between the capacitor CE6 and the voltage regulator tube U4B in parallel. The resistor R90, the resistor R91, the resistor R94 and the resistor R97 are all connected with a voltage regulator tube U4B, and the diode Q6 is connected with a voltage regulator tube U4B.

As shown in fig. 11, the trigger signal processing circuit includes an amplifier U11, a resistor R61, a resistor R62, a resistor R63, a resistor R64, a resistor R65, a resistor R66, a resistor R67, a resistor R68, a resistor R69, a resistor R70, a resistor R71, a resistor R72, a resistor R73, a resistor R74, a resistor R75, a regulator U12A, a regulator U12D, a regulator U12B, a regulator U12C, a capacitor C15, a capacitor C16, a capacitor C17, a capacitor C21, a diode D19, a diode D20, a diode D40, and a diode Q3. The resistor R74, the diode D40 and the voltage regulator tube U12A are respectively connected with the amplifier U11. The resistor R75 and the capacitor C15 are connected with a voltage regulator tube U12A, the capacitor C15 is connected with the resistor R72, the resistor R73, the resistor R64 and the voltage regulator tube U12B in series, the diode D19, the diode D20 and the voltage regulator tube U12D are connected between the resistor R72 and the resistor R64, the resistor R69 is connected with the voltage regulator tube U12B, and the resistor R65, the resistor R66, the resistor R70 and the resistor R71 are connected between the resistor R69 and the capacitor C15 in series. The resistor R68 and the capacitor C16 are connected with the resistor R69, the voltage regulator tube U12C is connected with the resistor R68, the resistor R63, the resistor R67 and the capacitor C17 are connected with the voltage regulator tube U12C, and the capacitor C21 and the diode Q3 are connected with the resistor R63.

The invention also discloses a high-voltage electrostatic spraying control method, which comprises the following steps:

and setting parameters through a human-computer interaction unit.

An external trigger signal is generated by an external trigger signal generating unit and is sent to a high-voltage pushing unit;

and the external switch trigger signal is subjected to optical coupling isolation through the trigger signal processing circuit and is sent to the main control unit, and an air circuit switching signal and a circuit switching signal are generated according to a feedback signal of the main control unit. Meanwhile, the first driving circuit and the second driving circuit receive PWM and DAC signals output by the main control unit and push a high-voltage pack module in the spray gun to generate high-voltage static electricity.

The main control unit receives the trigger signal processed by the trigger signal processing circuit, generates a feedback signal, a PWM (pulse width modulation) signal and a DAC (digital-to-analog converter) signal according to set parameters, and sends the generated feedback signal, the PWM signal and the DAC signal to the high-voltage pushing unit. Meanwhile, the main control unit collects current signals amplified and conditioned by the spray gun interface signal processing unit, and a closed-loop system is formed by adopting a PID algorithm, so that constant current and voltage are stabilized, and high-voltage static stability is ensured;

the signal processing unit receives the circuit switching signal through the spray gun interface, controls voltage output, simultaneously processes a current signal fed back by high-voltage static earth, amplifies and conditions the current signal and sends the amplified current signal to the main control unit for collection.

And the air pressure signal processing unit is used for receiving the air channel switching signal and feeding back the acquired analog quantity after signal processing to the main control unit. So that the main control unit controls the electromagnetic valve control circuit through algorithm operation PI to control the spraying fluidization air pressure and the atomization air pressure, and a closed-loop system is formed.

The high-voltage electrostatic spraying control system and the control method realize automatic control of four variables of electrostatic voltage, electrostatic current, flow velocity air pressure and atomization air pressure, provide multiple control modes, introduce a learning control strategy into electrostatic spraying control and realize high-quality spraying of the curved surface of a complex workpiece. The performance of the paint is obviously superior to that of the traditional spraying equipment through the test of various environments. The intelligent degree is high, and no danger exists; the pollution is effectively reduced, the materials are greatly saved, and the labor cost is greatly reduced.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.