Circuit structure of proportional valve controller

Abstract

The utility model discloses a circuit structure of a proportional valve controller, which comprises a first input circuit, a first output circuit, a first follow current circuit, a first RC absorption circuit, an MOS tube Q5 and a sampling circuit, a source electrode of the MOS tube Q5 is electrically connected with external + 24V voltage through the first input circuit, a grid electrode of the MOS tube Q5 is used as a first signal input end, and a second signal input end of the MOS tube Q5 is used as a second signal input end. The drain electrode of the MOS tube Q5 is electrically connected with the input end of the first output circuit, the output end of the first output circuit serves as a first signal output end, the output end of the first follow current circuit is electrically connected with the drain electrode of the MOS tube Q5, the on-off state of an MOS is controlled through an input signal, filtering shaping output is conducted through an inductor and a capacitor, and the output end of the first follow current circuit serves as a second signal output end. A control signal is calculated by software to output a PWM wave, and the final output signal is a sinusoidal signal with the flutter frequency of 50HZ. The circuit structure of the proportional valve controller has the advantages of being good in control accuracy and response speed.

Description

Technical Field

[0001] This utility model relates to the field of proportional valve technology, and in particular to a circuit structure for a proportional valve controller. Background Technology

[0002] Hydraulic proportional valves have wide applications in various fields, including industrial automation, machine tools, agriculture, aerospace, medical equipment, and the automotive industry. The development trend of hydraulic proportional valves is towards higher performance, smaller size, and greater integration. Proportional valves are further divided into ordinary proportional valves and servo proportional valves. Servo proportional valves integrate a controller and have built-in valve spool displacement feedback. Besides being easier to control, they can also acquire the valve opening size. However, servo proportional valves are often larger in size, and repair is difficult after a failure, with less adaptability.

[0003] A control circuit capable of driving a standard proportional valve is needed to meet practical requirements. Utility Model Content

[0004] To address the aforementioned problems, a circuit structure for a proportional valve controller is provided, aiming to solve the issues existing in the prior art.

[0005] The specific technical solution is as follows:

[0006] A circuit structure for a proportional valve controller includes a first input circuit, a first output circuit, a first freewheeling circuit, a first RC snubber circuit, a MOSFET Q5, and a sampling circuit. The source of the MOSFET Q5 is electrically connected to an external +24V voltage through the first input circuit. The gate of the MOSFET Q5 serves as a first signal input terminal. The drain of the MOSFET Q5 is electrically connected to the input terminal of the first output circuit. The output terminal of the first output circuit serves as a first signal output terminal. The output terminal of the first freewheeling circuit is electrically connected to the drain of the MOSFET Q5. The input terminal of the first freewheeling circuit is electrically connected to the first output circuit through the first RC snubber circuit. The common terminal of the first freewheeling circuit and the first RC snubber circuit is grounded through the sampling circuit.

[0007] The circuit structure of the aforementioned proportional valve controller also includes a second input circuit, a second output circuit, a second freewheeling circuit, a second RC snubber circuit, and a MOSFET Q6. The source of the MOSFET Q6 is electrically connected to an external +24V voltage through the second input circuit. The gate of the MOSFET Q6 serves as a second signal input terminal. The drain of the MOSFET Q6 is electrically connected to the input terminal of the second output circuit. The output terminal of the second output circuit serves as a second signal output terminal. The output terminal of the second freewheeling circuit is electrically connected to the drain of the MOSFET Q6. The input terminal of the second freewheeling circuit is electrically connected to the second output circuit through the second RC snubber circuit. The common terminal of the second freewheeling circuit and the second RC snubber circuit is grounded after passing through the sampling circuit.

[0008] The circuit structure of the above-mentioned proportional valve controller also has the following features: the first input circuit includes an inductor L12 and a resistor R42. One end of the inductor L12 is connected to an external +24V power supply as the first power input terminal, and the other end of the inductor L12 is connected to the source of the MOS transistor Q5. The gate of the MOS transistor Q5 is connected to the first power input terminal through the resistor R42.

[0009] The second input circuit includes an inductor L13 and a resistor R41. One end of the inductor L13 serves as the second power input terminal and is electrically connected to an external +24V source. The other end of the inductor L13 is electrically connected to the source of the MOSFET Q6. The gate of the MOSFET Q6 is electrically connected to the second power input terminal through the resistor R41.

[0010] The circuit structure of the above-mentioned proportional valve controller also has the following features: the first output circuit includes an inductor L18 and a diode D28; the drain of the MOS transistor Q5 is electrically connected to the anode of the diode D28 through the inductor L18; and the cathode of the diode D28 serves as the first signal output terminal.

[0011] The second output circuit includes an inductor L19 and a diode D29. The drain of the MOSFET Q6 is electrically connected to the anode of the diode D29 through the inductor L19, and the cathode of the diode D29 serves as the second signal output terminal.

[0012] The circuit structure of the above-mentioned proportional valve controller also has the following feature: the first RC absorption circuit includes a capacitor C74 and a resistor R70, and the anode of the diode D28 is sequentially electrically connected to the input terminal of the first freewheeling circuit through the capacitor C74 and the resistor R70.

[0013] The second RC snubber circuit includes a capacitor C75 and a resistor R67. The anode of the diode D29 is sequentially connected to the input terminal of the second freewheeling circuit through the capacitor C75 and the resistor R67.

[0014] The circuit structure of the above-mentioned proportional valve controller also has the following features: the first freewheeling circuit includes a diode D30, an inductor L20 and a resistor R69. The cathode of the diode D30 is electrically connected to the drain of the MOS transistor Q5, and the anode of the diode D30 is electrically connected to the resistor R70 after passing through the inductor L20 and the resistor R69 in sequence.

[0015] The second freewheeling circuit includes a diode D31, an inductor L21, and a resistor R68. The cathode of the diode D31 is electrically connected to the drain of the MOSFET Q6, and the anode of the diode D31 is electrically connected to the resistor R67 after passing through the inductor L21 and the resistor R68 in sequence.

[0016] The circuit structure of the aforementioned proportional valve controller also has the following characteristics: the sampling circuit includes a resistor R66, a capacitor C76, and a suppression diode 34. The resistor R66, capacitor C76, and suppression diode 34 are connected in parallel. One of the common terminals of the three in parallel is grounded, and the other common terminal serves as the acquisition terminal. The common terminal of the resistor R69 and the resistor R70 is electrically connected to the acquisition terminal, and the common terminal of the resistor R67 and the resistor R68 is also electrically connected to the acquisition terminal.

[0017] In summary, the beneficial effects of this scheme are:

[0018] The proportional valve controller circuit structure provided by this utility model controls the switching state of the MOS transistor through an input signal, and the output is filtered and shaped by an inductor and capacitor. The control signal is calculated by software to output a PWM wave, and the final output signal has a dithering frequency of 50Hz sine wave. The proportional valve controller circuit structure provided by this utility model has the advantages of good control accuracy and response speed. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the circuit structure of the proportional valve controller of this utility model. Detailed Implementation

[0020] The technical solution of this utility model will be clearly and completely described below with reference to its embodiments. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0021] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0022] The present invention will be further described below with reference to specific embodiments, but this is not intended to limit the present invention.

[0023] Figure 1 This is a schematic diagram of the circuit structure of the proportional valve controller of this utility model, as shown below. Figure 1 As shown, the circuit structure of the proportional valve controller provided in this embodiment includes a first input circuit, a first output circuit, a first freewheeling circuit, a first RC snubber circuit, a MOSFET Q5, and a sampling circuit. The source of the MOSFET Q5 is electrically connected to an external +24V voltage through the first input circuit. The gate of the MOSFET Q5 serves as the first signal input terminal. The drain of the MOSFET Q5 is electrically connected to the input terminal of the first output circuit. The output terminal of the first output circuit serves as the first signal output terminal. The output terminal of the first freewheeling circuit is electrically connected to the drain of the MOSFET Q5. The input terminal of the first freewheeling circuit is electrically connected to the first output circuit through the first RC snubber circuit. The common terminal of the first freewheeling circuit and the first RC snubber circuit is grounded after passing through the sampling circuit.

[0024] In the above embodiment, it further includes a second input circuit, a second output circuit, a second freewheeling circuit, a second RC snubber circuit, and a MOSFET Q6. The source of the MOSFET Q6 is electrically connected to an external +24V voltage through the second input circuit. The gate of the MOSFET Q6 serves as a second signal input terminal. The drain of the MOSFET Q6 is electrically connected to the input terminal of the second output circuit. The output terminal of the second output circuit serves as a second signal output terminal. The output terminal of the second freewheeling circuit is electrically connected to the drain of the MOSFET Q6. The input terminal of the second freewheeling circuit is electrically connected to the second output circuit through the second RC snubber circuit. The common terminal of the second freewheeling circuit and the second RC snubber circuit is grounded after passing through a sampling circuit.

[0025] In the above embodiment, the first input circuit includes an inductor L12 and a resistor R42. One end of the inductor L12 is connected to the external +24V as the first power input terminal, and the other end of the inductor L12 is connected to the source of the MOSFET Q5. The gate of the MOSFET Q5 is connected to the first power input terminal through the resistor R42.

[0026] The second input circuit includes an inductor L13 and a resistor R41. One end of the inductor L13 serves as the second power input terminal and is electrically connected to an external +24V source. The other end of the inductor L13 is electrically connected to the source of the MOSFET Q6. The gate of the MOSFET Q6 is electrically connected to the second power input terminal through the resistor R41.

[0027] It should be noted that both the first and second signal input terminals are calculated by software to output PWM waves, and the final output signal has a dithering frequency of 50Hz sine wave and a basic PWM frequency of 1kHz.

[0028] In the above embodiment, the first output circuit includes an inductor L18 and a diode D28. The drain of the MOSFET Q5 is electrically connected to the anode of the diode D28 through the inductor L18, and the cathode of the diode D28 serves as the first signal output terminal.

[0029] The second output circuit includes an inductor L19 and a diode D29. The drain of the MOSFET Q6 is electrically connected to the anode of the diode D29 through the inductor L19, and the cathode of the diode D29 serves as the second signal output terminal.

[0030] In the above embodiment, the first RC absorption circuit includes a capacitor C74 and a resistor R70, and the anode of the diode D28 is sequentially connected to the input terminal of the first freewheeling circuit through the capacitor C74 and the resistor R70.

[0031] The second RC snubber circuit includes a capacitor C75 and a resistor R67. The anode of diode D29 is sequentially connected to the input terminal of the second freewheeling circuit through capacitor C75 and resistor R67.

[0032] In the above embodiment, the first freewheeling circuit includes a diode D30, an inductor L20 and a resistor R69. The cathode of the diode D30 is electrically connected to the drain of the MOSFET Q5, and the anode of the diode D30 is electrically connected to the resistor R70 after passing through the inductor L20 and the resistor R69 in sequence.

[0033] The second freewheeling circuit includes a diode D31, an inductor L21, and a resistor R68. The cathode of the diode D31 is electrically connected to the drain of the MOSFET Q6, and the anode of the diode D31 is electrically connected to the resistor R67 after passing through the inductor L21 and the resistor R68 in sequence.

[0034] In the above embodiment, the sampling circuit includes a resistor R66, a capacitor C76, and a suppression diode 34. The resistor R66, capacitor C76, and suppression diode 34 are connected in parallel. One of the common terminals of the three in parallel is grounded, and the other common terminal of the three in parallel serves as the acquisition terminal. The common terminal of resistors R69 and R70 is electrically connected to the acquisition terminal, and the common terminal of resistors R67 and R68 is also electrically connected to the acquisition terminal.

[0035] It should be noted that, through functional analysis of the valve body, a chatter control mode is introduced for valve body control. This involves periodically varying the current magnitude of the valve core near a given current, causing the valve core to vibrate at a certain frequency. When the valve core is in chatter mode, its mechanical friction is in dynamic friction mode, which simultaneously overcomes the valve body's hysteresis effect. When the control current changes, it can react very quickly and has a certain degree of control accuracy.

[0036] Working principle: +24V is filtered by inductor L12 and then applied to the source of MOSFET Q5. Under the control of the signal input at the first signal input terminal, MOSFET Q5 intermittently turns on and off, outputting a 24V voltage. This voltage is then filtered by inductor L18 and rectified by diode D28, finally supplying 24V to the proportional valve. When MOSFET Q5 is on and off, the proportional valve core coil generates a large back electromotive force (EMF). This back EMF can affect MOSFET Q5 and, in severe cases, may break it down. Diode D30, inductor L20, and resistor R69 provide a freewheeling path to dissipate the back EMF, thus protecting the valve. The MOSFET, capacitor C74, and resistor R70 form an RC snubber circuit, which is connected in parallel across the proportional valve core. When power is off, a surge pulse is generated momentarily when the coil is released. This surge pulse can interfere with sensitive devices such as the MOSFET, causing malfunctions. Therefore, an RC snubber circuit is used to absorb the surge pulse. Resistor R66 is a sampling resistor that samples the current of the proportional valve, converts it into voltage, and feeds the sampled voltage back to the CPU to control the duty cycle of the output PWM wave and adjust the output of the proportional valve. Capacitor C76 filters the sampled voltage to absorb voltage glitches, and transient suppression diode D34 protects the sampled voltage by absorbing any transient high voltages that may occur.

[0037] The above are merely preferred embodiments of the present utility model and are not intended to limit the implementation methods and protection scope of the present utility model. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the content of the present utility model specification should be included within the protection scope of the present utility model.

Claims

1. A circuit structure for a proportional valve controller, characterized in that, The circuit includes a first input circuit, a first output circuit, a first freewheeling circuit, a first RC snubber circuit, a MOSFET Q5, and a sampling circuit. The source of the MOSFET Q5 is electrically connected to an external +24V voltage through the first input circuit. The gate of the MOSFET Q5 serves as a first signal input terminal. The drain of the MOSFET Q5 is electrically connected to the input terminal of the first output circuit. The output terminal of the first output circuit serves as a first signal output terminal. The output terminal of the first freewheeling circuit is electrically connected to the drain of the MOSFET Q5. The input terminal of the first freewheeling circuit is electrically connected to the first output circuit through the first RC snubber circuit. The common terminal of the first freewheeling circuit and the first RC snubber circuit is grounded through the sampling circuit.

2. The circuit structure of a proportional valve controller according to claim 1, characterized in that: It also includes a second input circuit, a second output circuit, a second freewheeling circuit, a second RC snubber circuit, and a MOSFET Q6. The source of the MOSFET Q6 is electrically connected to an external +24V voltage through the second input circuit. The gate of the MOSFET Q6 serves as a second signal input terminal. The drain of the MOSFET Q6 is electrically connected to the input terminal of the second output circuit. The output terminal of the second output circuit serves as a second signal output terminal. The output terminal of the second freewheeling circuit is electrically connected to the drain of the MOSFET Q6. The input terminal of the second freewheeling circuit is electrically connected to the second output circuit through the second RC snubber circuit. The common terminal of the second freewheeling circuit and the second RC snubber circuit is grounded after passing through the sampling circuit.

3. The circuit structure of a proportional valve controller according to claim 2, characterized in that: The first input circuit includes an inductor L12 and a resistor R42. One end of the inductor L12 serves as the first power input terminal and is electrically connected to an external +24V source. The other end of the inductor L12 is electrically connected to the source of the MOSFET Q5. The gate of the MOSFET Q5 is electrically connected to the first power input terminal through the resistor R42. The second input circuit includes an inductor L13 and a resistor R41. One end of the inductor L13 serves as the second power input terminal and is electrically connected to an external +24V source. The other end of the inductor L13 is electrically connected to the source of the MOSFET Q6. The gate of the MOSFET Q6 is electrically connected to the second power input terminal through the resistor R41.

4. The circuit structure of a proportional valve controller according to claim 2, characterized in that: The first output circuit includes an inductor L18 and a diode D28. The drain of the MOSFET Q5 is electrically connected to the anode of the diode D28 through the inductor L18, and the cathode of the diode D28 serves as the first signal output terminal. The second output circuit includes an inductor L19 and a diode D29. The drain of the MOSFET Q6 is electrically connected to the anode of the diode D29 through the inductor L19, and the cathode of the diode D29 serves as the second signal output terminal.

5. The circuit structure of a proportional valve controller according to claim 4, characterized in that: The first RC snubber circuit includes a capacitor C74 and a resistor R70. The anode of the diode D28 is sequentially connected to the input terminal of the first freewheeling circuit through the capacitor C74 and the resistor R70. The second RC snubber circuit includes a capacitor C75 and a resistor R67. The anode of the diode D29 is sequentially connected to the input terminal of the second freewheeling circuit through the capacitor C75 and the resistor R67.

6. The circuit structure of a proportional valve controller according to claim 5, characterized in that: The first freewheeling circuit includes a diode D30, an inductor L20, and a resistor R69. The cathode of the diode D30 is electrically connected to the drain of the MOSFET Q5, and the anode of the diode D30 is electrically connected to the resistor R70 after passing through the inductor L20 and the resistor R69 in sequence. The second freewheeling circuit includes a diode D31, an inductor L21, and a resistor R68. The cathode of the diode D31 is electrically connected to the drain of the MOSFET Q6, and the anode of the diode D31 is electrically connected to the resistor R67 after passing through the inductor L21 and the resistor R68 in sequence.

7. The circuit structure of a proportional valve controller according to claim 6, characterized in that: The sampling circuit includes a resistor R66, a capacitor C76, and a suppression diode 34. The resistor R66, capacitor C76, and suppression diode 34 are connected in parallel. One of the common terminals of the three in parallel is grounded, and the other common terminal serves as the acquisition terminal. The common terminal of the resistor R69 and the resistor R70 is electrically connected to the acquisition terminal, and the common terminal of the resistor R67 and the resistor R68 is also electrically connected to the acquisition terminal.

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