A proportional valve driver with a chattering function

Abstract

The application discloses a proportional valve driver with a chatter function, comprising a microprocessor, a proportional valve control signal input circuit, a fundamental wave generating circuit, a PWM wave generating circuit, a triangular wave generating circuit, an AND gate circuit, a comparison circuit and a proportional valve control signal output circuit, and a communication circuit; the input ends of the fundamental wave generating circuit, the PWM wave generating circuit and the triangular wave generating circuit are connected with the microprocessor; the output ends of the fundamental wave generating circuit and the PWM wave generating circuit are connected with the input ends of the AND gate circuit respectively; the output end of the triangular wave generating circuit and the output end of the AND gate circuit are connected with the input ends of the comparison circuit respectively; the output end of the comparison circuit is connected with the input end of the proportional valve control signal output circuit; the output end of the proportional valve control signal output circuit is connected with an electromagnet of a proportional valve; one end of the communication circuit is connected with the microprocessor; and the other end of the communication circuit is connected with a target device.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of industrial automation control, and particularly relates to a proportional valve driver with a chatter function. BACKGROUND

[0002] With the continuous development of industrial automation control technology, hydraulic systems have been widely used in various industrial fields. As an important control component, the hydraulic proportional valve is used for precise control of pressure and flow in the hydraulic system by converting electrical signals into corresponding force or displacement. The existing hydraulic proportional valve is generally driven by a direct current proportional electromagnet, but in actual application, there are problems such as slow response speed, low control precision, and large hysteresis effect, which seriously affect the dynamic response and control stability of the system.

[0003] The traditional hydraulic proportional valve driver usually uses a low-frequency PWM wave as a driving signal. This driving method is prone to generate static friction when the valve core is stationary, which causes the valve core to lag when starting, resulting in slow system response. In addition, due to the inability of the control signal to dynamically change, the system may exhibit stickiness and friction lag during operation, affecting the overall response speed and sensitivity. SUMMARY

[0004] Therefore, the present application provides a proportional valve driver with a chatter function to solve the problem of slow response speed and low control precision of the existing hydraulic proportional valve caused by static friction and hysteresis effect.

[0005] In order to achieve the above purpose, the present application provides the following technical solutions:

[0006] A proportional valve driver with a chatter function, comprising a microprocessor, a proportional valve control signal input circuit, a fundamental wave generation circuit, a PWM wave generation circuit, a triangular wave generation circuit, an AND gate circuit, a comparison circuit, and a proportional valve control signal output circuit, and a communication circuit;

[0007] The input end of the proportional valve control signal input circuit is connected with a 0-10V voltage output end, and the output end of the proportional valve control signal input circuit is connected with the microprocessor;

[0008] The input ends of the fundamental wave generation circuit, the PWM wave generation circuit, and the triangular wave generation circuit are connected with the microprocessor, the output ends of the fundamental wave generation circuit and the PWM wave generation circuit are respectively connected with the input ends of the AND gate circuit, the output end of the triangular wave generation circuit and the output end of the AND gate circuit are respectively connected with the input ends of the comparison circuit, the output end of the comparison circuit is connected with the input end of the proportional valve control signal output circuit, and the output end of the proportional valve control signal output circuit is connected with the electromagnet of the proportional valve;

[0009] One end of the communication circuit is connected with the microprocessor, and the other end of the communication circuit is connected with the target device.

[0010] Optionally, the microprocessor comprises a first chip U1A, and the first chip U1A is an STM32F103VET6 chip.

[0011] Optionally, the proportional valve control signal input circuit comprises an eighth resistor R8 and a ninth resistor R9.

[0012] One end of the eighth resistor R8 is connected with the 0-10V voltage output end, and the other end of the eighth resistor R8 is connected with one end of the ninth resistor R9, and the other end of the ninth resistor R9 is grounded.

[0013] The connection end of the eighth resistor R8 and the ninth resistor R9 is connected with the 32th pin of the first chip U1A.

[0014] Optionally, the fundamental wave generation circuit and the PWM wave generation circuit are timer circuits inside the microprocessor, and the triangular wave generation circuit is a DAC peripheral circuit inside the microprocessor.

[0015] Optionally, the AND gate circuit comprises a second chip U2A, and the second chip U2A is a 74F08 chip.

[0016] The 1st pin of the second chip U2A is connected with the 67th pin of the first chip U1A, the 2nd pin of the second chip U2A is connected with the 63th pin of the first chip U1A, and the 3rd pin of the second chip U2A is connected with the input end of the comparison circuit.

[0017] The 67th pin of the first chip U1A is the output end of the fundamental wave generation circuit, and the 63th pin of the first chip U1A is the output end of the PWM wave generation circuit.

[0018] Optionally, the comparison circuit comprises a third chip U3A, and the third chip U3A is an LM339A chip.

[0019] The 5th pin of the third chip U3A is connected with the 3rd pin of the second chip U2A, the 4th pin of the third chip U3A is connected with the 29th pin of the first chip U1A, and the 2nd pin of the third chip U3A is connected with the input end of the proportional valve control signal output circuit.

[0020] The 3rd pin of the third chip U3A is connected with a 3.3V power supply output end, and the 12th pin of the third chip U3A is grounded.

[0021] The 29th pin of the first chip U1A is an output terminal of the triangular wave generating circuit.

[0022] Optionally, the proportional valve control signal output circuit comprises a first resistor R1 and a first transistor Q1.

[0023] One end of the first resistor R1 is connected with the 2nd pin of the third chip U3A, and the other end of the first resistor R1 is connected with the base of the first transistor Q1.

[0024] The collector of the first transistor Q1 is connected with the 2nd pin of the first connection terminal P1, and the emitter of the first transistor Q1 is grounded.

[0025] The 1st pin of the first connection terminal P1 is connected with a 12V power output terminal.

[0026] Optionally, the first transistor Q1 is an NPN type power transistor.

[0027] Optionally, the communication circuit comprises a fourth chip U4, and the fourth chip U4 is an SP3485 chip.

[0028] The 1st pin of the fourth chip U4 is connected with the 26th pin of the first chip U1A; the 2nd pin of the fourth chip U4 is connected with the 3rd pin of the fourth chip U4; the 3rd pin of the fourth chip U4 is connected with the 24th pin of the first chip U1A; the 4th pin of the fourth chip U4 is connected with the 25th pin of the first chip U1A; the 5th pin of the fourth chip U4 is grounded; the 6th pin of the fourth chip U4 is connected with one end of a fourth resistor R4; the 7th pin of the fourth chip U4 is connected with one end of a third resistor R3; the 8th pin of the fourth chip U4 is connected with a 3.3V power output terminal.

[0029] The other end of the fourth resistor R4 is divided into five paths, the first path is connected with one end of a seventh resistor R7, the second path is connected with one end of a fifth resistor R5, the third path is connected with one end of a second TVS tube T2, the fourth path is connected with one end of a third TVS tube T3, and the fifth path is connected with one end of a second fuse F2; the other end of the seventh resistor R7 is connected with the 3.3V power output terminal; the other end of the third TVS tube T3 is grounded; the other end of the second fuse F2 is an external 485 communication interface line A.

[0030] The other end of the third resistor R3 is divided into five paths, the first path is connected with the other end of the fifth resistor R5, the second path is connected with one end of the sixth resistor R6, the third path is connected with one end of the first TVS tube T1, the fourth path is connected with the other end of the second TVS tube T2, and the fifth path is connected with one end of the first fuse F1; the other end of the sixth resistor R6 is connected with the 3.3V power output end; the other end of the first TVS tube T1 is grounded; and the other end of the first fuse F1 is an external 485 communication interface line B.

[0031] Optionally, the fundamental wave output by the fundamental wave generating circuit is a square wave with a high-frequency duty cycle fixed at 50%, and the frequency of the fundamental wave is 4 kHz.

[0032] Compared with the prior art, the application has at least the following beneficial effects:

[0033] The application provides a proportional valve driver with a chattering function, comprising a microprocessor, a proportional valve control signal input circuit, a fundamental wave generating circuit, a PWM wave generating circuit, a triangular wave generating circuit, an AND gate circuit, a comparison circuit and a proportional valve control signal output circuit, and a communication circuit. The input ends of the fundamental wave generating circuit, the PWM wave generating circuit and the triangular wave generating circuit are connected with the microprocessor, the output ends of the fundamental wave generating circuit and the PWM wave generating circuit are connected with the input ends of the AND gate circuit respectively, the output end of the triangular wave generating circuit and the output end of the AND gate circuit are connected with the input ends of the comparison circuit respectively, the output end of the comparison circuit is connected with the input end of the proportional valve control signal output circuit, and the output end of the proportional valve control signal output circuit is connected with an electromagnet of a proportional valve. The microprocessor generates a fundamental wave, a PWM wave and a low-frequency triangular wave, and the fundamental wave, the PWM wave and the low-frequency triangular wave are superimposed and controlled in the AND gate circuit and the comparison circuit, so that an adjustable chattering signal is realized. The independent and adjustable chattering signal can keep the spool in a small continuous movement, effectively reduces the static friction, and makes the system response faster. At the same time, the chattering function can avoid the hysteresis effect caused by the static friction when the spool is in motion, so that the system can more smoothly and accurately adjust the valve opening, thereby improving the control precision and stability. In addition, the dynamic response speed of the proportional valve is also enhanced, so that the proportional valve can quickly and accurately respond to the change of the control signal. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more intuitively illustrate the prior art and the present application, exemplary drawings are given below. It should be understood that the specific shapes, configurations shown in the drawings should not be considered as limiting conditions in the implementation of the present application; for example, based on the technical concepts disclosed in the present application and the exemplary drawings, those skilled in the art can easily make routine adjustments or further optimizations on the increase / decrease / assignment of certain units (components), specific shapes, positional relationships, connection modes, size ratio relationships, etc.

[0035] Figure 1 A circuit principle block diagram of a proportional valve driver with a chatter function provided for an embodiment of the present application;

[0036] Figure 2 A circuit principle diagram of a microprocessor provided for an embodiment of the present application;

[0037] Figure 3 A circuit principle diagram of a proportional valve control signal input circuit provided for an embodiment of the present application;

[0038] Figure 4 A circuit principle diagram of an AND gate circuit, a comparison circuit and a proportional valve control signal output circuit provided for an embodiment of the present application;

[0039] Figure 5 A circuit principle diagram of a communication circuit provided for an embodiment of the present application. DETAILED DESCRIPTION

[0040] The present application is further described in detail below with reference to specific embodiments in conjunction with the accompanying drawings.

[0041] In the description of the present application: unless otherwise specified, the meaning of "a plurality of" is two or more. The terms "first", "second", "third" and the like in the present application are intended to distinguish the objects referred to, and do not have special technical connotations (for example, should not be understood as emphasizing importance or order, etc.). The expressions "include", "contain", "have" and the like also mean "not limited to" (certain units, components, materials, steps, etc.).

[0042] The terms such as "upper", "lower", "left", "right", "middle" and the like referred to in the present application are generally indications for the purpose of intuitive understanding based on the relative positional relationship in general, and are not absolute limitations on the positional relationship in the actual product.

[0043] Proportional valve full name electro-hydraulic proportional control valve, is a kind of input electrical signal proportional conversion into force or displacement, thereby continuously controlling pressure, flow and other parameters of a kind of hydraulic valve. Proportional valve is composed of DC proportional electric impact magnet and hydraulic valve. With the continuous improvement of automation degree, solenoid valve as the key component of fluid passage, the stability and reliability of its performance is particularly important. However, the traditional solenoid valve driver often exists slow response speed, low control degree and other problems, which affects the operation effect of the whole system. At present, the driving controller directly uses low frequency PWM wave as the proportional valve driving signal, the displacement or thrust of the solenoid valve core of the hydraulic proportional valve is proportional to the current of the flow path coil, if the fixed does not change, the valve core position is also fixed. When the current is changed, the valve core starts to act from the static state, and the so-called stick effect is generated, the hysteresis is increased, the response speed and sensitivity are reduced. Therefore, a small amplitude vibration signal is applied to the valve core to make it always in motion, and the static friction is converted into dynamic friction, so as to improve the response speed and response sensitivity, and reduce the hysteresis. This small amplitude vibration is called "chatter". Therefore, the present application aims to provide a new type of solenoid valve driver with chatter function, which solves the problems of slow response speed and low control precision of the existing hydraulic proportional valve caused by static friction and hysteresis effect.

[0044] As shown in Figure 1 A proportional valve driver with chatter function, comprising a microprocessor, a proportional valve control signal input circuit, a fundamental wave generating circuit, a PWM wave generating circuit, a triangular wave generating circuit, an AND gate circuit, a comparison circuit and a proportional valve control signal output circuit, and a communication circuit.

[0045] The input end of the proportional valve control signal input circuit is connected with the 0-10V voltage output end, and the output end of the proportional valve control signal input circuit is connected with the microprocessor.

[0046] The input ends of the fundamental wave generating circuit, the PWM wave generating circuit and the triangular wave generating circuit are connected with the microprocessor, the output ends of the fundamental wave generating circuit and the PWM wave generating circuit are connected with the input ends of the AND gate circuit respectively, the output end of the triangular wave generating circuit and the output end of the AND gate circuit are connected with the input ends of the comparison circuit respectively, the output end of the comparison circuit is connected with the input end of the proportional valve control signal output circuit, and the output end of the proportional valve control signal output circuit is connected with the solenoid of the proportional valve.

[0047] One end of the communication circuit is connected with the microprocessor, and the other end of the communication circuit is connected with the target device.

[0048] The application discloses a proportional valve driver with fast response and high precision control characteristics. The system comprises a microprocessor, a microprocessor communication interface, a driving power supply part, a signal input end, a signal superposition circuit and a driving output end.

[0049] In the prior art, the following problems exist: for a closed-loop control system, the hysteresis of a proportional valve is too large, causing system vibration and closed-loop control failure; the hysteresis is mainly caused by the frictional force between a valve core and a valve body and static hydraulic force; for a direct drive valve driven by a proportional electromagnet, the hysteresis of the proportional electromagnet is also an important source of the hysteresis of the proportional valve; superimposed independent flutter: a triangular wave is superimposed on a linear driving current and is commonly used for driving a servo valve with a small coil current; the superimposed independent flutter is independent flutter, but the driving efficiency is low and the heat generation is serious; parasitic PWM flutter: a charging and discharging waveform (approximate triangular wave) generated by directly driving a PWM wave (50-500 Hz) is used as a source of flutter, the parasitic PWM flutter is parasitic flutter, and the amplitude of the flutter is not independently adjustable; the electromagnetic valve has high heat generation, low working efficiency and serious hysteresis.

[0050] Compared with the prior art, the proportional valve driver with the flutter function can effectively reduce the hysteresis effect, improve the control precision, reduce the power consumption, prolong the service life of the electromagnetic valve, improve the reliability and accuracy of a fluid control system and be suitable for various industrial scenes, and has high market promotion value.

[0051] The application provides a proportional valve driver with a chatter function, comprising a microprocessor, a proportional valve control signal input circuit, a fundamental wave generating circuit, a PWM wave generating circuit, a triangular wave generating circuit, an AND gate circuit, a comparison circuit and a proportional valve control signal output circuit, and a communication circuit. The input ends of the fundamental wave generating circuit, the PWM wave generating circuit and the triangular wave generating circuit are connected with the microprocessor, the output ends of the fundamental wave generating circuit and the PWM wave generating circuit are respectively connected with the input ends of the AND gate circuit, the output end of the triangular wave generating circuit and the output end of the AND gate circuit are respectively connected with the input ends of the comparison circuit, the output end of the comparison circuit is connected with the input end of the proportional valve control signal output circuit, and the output end of the proportional valve control signal output circuit is connected with an electromagnet of a proportional valve. The microprocessor is used for generating a fundamental wave, a PWM wave and a low-frequency triangular wave, and the fundamental wave, the PWM wave and the low-frequency triangular wave are superimposed and controlled in the AND gate circuit and the comparison circuit, so that an adjustable chatter signal is realized. The independent and adjustable chatter signal can keep a small continuous movement of a valve core, effectively reduce static friction, and make the system response faster. Meanwhile, the chatter function can avoid the hysteresis effect caused by static friction when the valve core is in action, so that the system can more smoothly and accurately adjust the valve opening, thereby improving the control precision and stability. In addition, the dynamic response speed of the proportional valve is enhanced, and it is ensured that the proportional valve can quickly and accurately respond to the change of the control signal.

[0052] As shown in Figure 2 In a possible embodiment, the microprocessor comprises a first chip U1A, and the first chip U1A is an STM32F103VET6 chip.

[0053] In the embodiment, the microprocessor is a high-performance 32-bit ARM microprocessor. The rich peripherals such as on-chip serial communication, analog-to-digital conversion and general-purpose IO meet the functional requirements, are the main controller of the core algorithm, waveform signal generation output and other functions.

[0054] As shown in Figure 3 In a possible embodiment, the proportional valve control signal input circuit comprises an eighth resistor R8 and a ninth resistor R9.

[0055] One end of the eighth resistor R8 is connected with the 0-10V voltage output end, and the other end of the eighth resistor R8 is connected with one end of the ninth resistor R9. The other end of the ninth resistor R9 is grounded.

[0056] The connection ends of the eighth resistor R8 and the ninth resistor R9 are connected with the 32th pin of the first chip U1A.

[0057] In the embodiment, the proportional valve control signal input circuit is used for analog signal acquisition, and a 0-10V voltage input signal is used to control the opening of the proportional valve.

[0058] In a possible embodiment, the fundamental wave generation circuit and the PWM wave generation circuit are timer circuits inside the microprocessor; and the triangular wave generation circuit is a DAC peripheral circuit inside the microprocessor.

[0059] In the embodiment, the fundamental wave generation circuit generates a high-frequency square wave with a fixed duty cycle of 50%, and the frequency is set to 4KHz; the PWM wave generation circuit generates a square wave signal with an adjustable duty cycle, which is used to adjust the electrical signal of the proportional valve opening; and the triangular wave generation circuit generates a triangular wave signal used for superposition on the fundamental wave.

[0060] As shown in Figure 4 In a possible embodiment, the AND gate circuit includes a second chip U2A, and the second chip U2A is a 74F08 chip.

[0061] The first pin of the second chip U2A is connected with the 67th pin of the first chip U1A; the second pin of the second chip U2A is connected with the 63rd pin of the first chip U1A; and the third pin of the second chip U2A is connected with the input end of the comparison circuit.

[0062] The 67th pin of the first chip U1A is the output end of the fundamental wave generation circuit, and the 63rd pin of the first chip U1A is the output end of the PWM wave generation circuit.

[0063] In the embodiment, the PWM wave and the fundamental wave are superimposed by the AND gate circuit.

[0064] As shown in Figure 4 In a possible embodiment, the comparison circuit includes a third chip U3A, and the third chip U3A is an LM339A chip.

[0065] The fifth pin of the third chip U3A is connected with the third pin of the second chip U2A; the fourth pin of the third chip U3A is connected with the 29th pin of the first chip U1A; and the second pin of the third chip U3A is connected with the input end of the proportional valve control signal output circuit.

[0066] The third pin of the third chip U3A is connected with a 3.3V power supply output end, and the 12th pin of the third chip U3A is grounded.

[0067] The 29th pin of the first chip U1A is an output terminal of the triangular wave generating circuit.

[0068] In the embodiment, the signal obtained by superimposing the PWM wave and the fundamental wave is combined with the triangular wave, and the voltage comparator outputs the three kinds of waveforms superimposed.

[0069] As shown in the figure, in a possible embodiment, the proportional valve control signal output circuit comprises a first resistor R1 and a first transistor Q1. Figure 4

[0070] One end of the first resistor R1 is connected to the 2nd pin of the third chip U3A, and the other end of the first resistor R1 is connected to the base of the first transistor Q1.

[0071] The collector of the first transistor Q1 is connected to the 2nd pin of the first connection terminal P1, and the emitter of the first transistor Q1 is grounded.

[0072] The 1st pin of the first connection terminal P1 is connected to the output terminal of the 12V power supply.

[0073] In a possible embodiment, the first transistor Q1 is an NPN type power transistor.

[0074] In the embodiment, the first transistor Q1 is used as a power output in the rear stage to drive the electromagnetic iron to control the opening of the proportional valve.

[0075] As shown in the figure, in a possible embodiment, the communication circuit comprises a fourth chip U4, and the fourth chip U4 is an SP3485 chip. Figure 5 The 1st pin of the fourth chip U4 is connected to the 26th pin of the first chip U1A; the 2nd pin of the fourth chip U4 is connected to the 3rd pin of the fourth chip U4; the 3rd pin of the fourth chip U4 is connected to the 24th pin of the first chip U1A; the 4th pin of the fourth chip U4 is connected to the 25th pin of the first chip U1A; the 5th pin of the fourth chip U4 is grounded; one end of the fourth resistor R4 is connected to the 6th pin of the fourth chip U4; one end of the third resistor R3 is connected to the 7th pin of the fourth chip U4; the 8th pin of the fourth chip U4 is connected to the output terminal of the 3.3V power supply.

[0076]

[0077] ​​The other end of the fourth resistor R4 is divided into five paths, the first path is connected with one end of the seventh resistor R7, the second path is connected with one end of the fifth resistor R5, the third path is connected with one end of the second TVS tube T2, the fourth path is connected with one end of the third TVS tube T3, and the fifth path is connected with one end of the second fuse F2; the other end of the seventh resistor R7 is connected with the 3.3V power output end; the other end of the third TVS tube T3 is grounded; and the other end of the second fuse F2 is connected with the external 485 communication interface line A.

[0078] The other end of the third resistor R3 is divided into five paths, the first path is connected with the other end of the fifth resistor R5, the second path is connected with one end of the sixth resistor R6, the third path is connected with one end of the first TVS tube T1, the fourth path is connected with the other end of the second TVS tube T2, and the fifth path is connected with one end of the first fuse F1; the other end of the sixth resistor R6 is connected with the 3.3V power output end; the other end of the first TVS tube T1 is grounded; and the other end of the first fuse F1 is connected with the external 485 communication interface line B.

[0079] In the embodiment, the communication circuit is used to generate a data communication interface, and the proportional valve is controlled in opening degree through the data interface.

[0080] In a possible embodiment, the fundamental wave generated by the fundamental wave generating circuit is a square wave with a high frequency duty cycle fixed at 50%, and the frequency of the fundamental wave is 4 kHz.

[0081] The technical features of the above embodiments can be combined in any manner (as long as the combination of the technical features does not exist contradictions), in order to make the description simple, not all possible combinations of the technical features in the above embodiments are described; these embodiments which are not explicitly written should also be considered as the scope of the present disclosure.

Claims

1. A proportional valve driver with a chattering function, characterized by, The proportional valve driver comprises a microprocessor, a proportional valve control signal input circuit, a fundamental wave generating circuit, a PWM wave generating circuit, a triangular wave generating circuit, an AND gate circuit, a comparison circuit, a proportional valve control signal output circuit, and a communication circuit; The microprocessor comprises a first chip U1A, which is an STM32F103VET6 chip; An input end of the proportional valve control signal input circuit is connected with a 0-10V voltage output end, and an output end of the proportional valve control signal input circuit is connected with the microprocessor; Input ends of the fundamental wave generating circuit, the PWM wave generating circuit and the triangular wave generating circuit are connected with the microprocessor, output ends of the fundamental wave generating circuit and the PWM wave generating circuit are respectively connected with input ends of the AND gate circuit, an output end of the triangular wave generating circuit and an output end of the AND gate circuit are respectively connected with input ends of the comparison circuit, an output end of the comparison circuit is connected with an input end of the proportional valve control signal output circuit, and an output end of the proportional valve control signal output circuit is connected with an electromagnet of a proportional valve; One end of the communication circuit is connected with the microprocessor, and the other end of the communication circuit is connected with a target device; The proportional valve control signal input circuit comprises an eighth resistor R8 and a ninth resistor R9; One end of the eighth resistor R8 is connected with the 0-10V voltage output end, and the other end of the eighth resistor R8 is connected with one end of the ninth resistor R9, and the other end of the ninth resistor R9 is grounded; Connection ends of the eighth resistor R8 and the ninth resistor R9 are connected with a 32th pin of the first chip U1A; The fundamental wave generating circuit and the PWM wave generating circuit are timer circuits inside the microprocessor, and the triangular wave generating circuit is a DAC peripheral circuit inside the microprocessor; The AND gate circuit comprises a second chip U2A, which is a 74F08 chip; A 1st pin of the second chip U2A is connected with a 67th pin of the first chip U1A, a 2nd pin of the second chip U2A is connected with a 63th pin of the first chip U1A, and a 3rd pin of the second chip U2A is connected with an input end of the comparison circuit; The 67th pin of the first chip U1A is an output end of the fundamental wave generating circuit, and the 63th pin of the first chip U1A is an output end of the PWM wave generating circuit.

2. The proportional valve driver with a chattering function according to claim 1, characterized in that, The comparison circuit comprises a third chip U3A, which is an LM339A chip; A 5th pin of the third chip U3A is connected with the 3rd pin of the second chip U2A, a 4th pin of the third chip U3A is connected with a 29th pin of the first chip U1A, and a 2nd pin of the third chip U3A is connected with an input end of the proportional valve control signal output circuit; A 3rd pin of the third chip U3A is connected with a 3.3V power supply output end, and a 12th pin of the third chip U3A is grounded. The 29th pin of the first chip U1A is an output terminal of the triangular wave generating circuit.

3. The proportional valve driver with a chattering function according to claim 2, characterized in that, The proportional valve control signal output circuit comprises a first resistor R1 and a first transistor Q1. One end of the first resistor R1 is connected with the 2nd pin of the third chip U3A, and the other end of the first resistor R1 is connected with the base of the first transistor Q1. The collector of the first transistor Q1 is connected with the 2nd pin of the first connection terminal P1, and the emitter of the first transistor Q1 is grounded. The 1st pin of the first connection terminal P1 is connected with the output terminal of a 12V power supply.

4. The proportional valve driver with a chattering function according to claim 3, wherein The first transistor Q1 is an NPN type high-power transistor.

5. The proportional valve driver with chatter function according to claim 1, wherein The communication circuit comprises a fourth chip U4, and the fourth chip U4 is an SP3485 chip. The 1st pin of the fourth chip U4 is connected with the 26th pin of the first chip U1A; the 2nd pin of the fourth chip U4 is connected with the 3rd pin of the fourth chip U4; the 3rd pin of the fourth chip U4 is connected with the 24th pin of the first chip U1A; the 4th pin of the fourth chip U4 is connected with the 25th pin of the first chip U1A; the 5th pin of the fourth chip U4 is grounded; the 6th pin of the fourth chip U4 is connected with one end of a fourth resistor R4; the 7th pin of the fourth chip U4 is connected with one end of a third resistor R3; the 8th pin of the fourth chip U4 is connected with the output terminal of a 3.3V power supply. The other end of the fourth resistor R4 is divided into five paths, the first path is connected with one end of a seventh resistor R7, the second path is connected with one end of a fifth resistor R5, the third path is connected with one end of a second TVS tube T2, the fourth path is connected with one end of a third TVS tube T3, and the fifth path is connected with one end of a second fuse F2; the other end of the seventh resistor R7 is connected with the output terminal of the 3.3V power supply; the other end of the third TVS tube T3 is grounded; the other end of the second fuse F2 is an external 485 communication interface line A. The other end of the third resistor R3 is divided into five paths, the first path is connected with the other end of the fifth resistor R5, the second path is connected with one end of a sixth resistor R6, the third path is connected with one end of a first TVS tube T1, the fourth path is connected with the other end of the second TVS tube T2, and the fifth path is connected with one end of a first fuse F1; the other end of the sixth resistor R6 is connected with the output terminal of the 3.3V power supply; the other end of the first TVS tube T1 is grounded; the other end of the first fuse F1 is an external 485 communication interface line B.

6. The proportional valve driver with chatter function according to claim 1, wherein The fundamental wave output by the fundamental wave generating circuit is a square wave with a fixed 50% duty cycle and a frequency of 4kHz.

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