Wide-temperature-range direct-drive servo valve

Abstract

The invention discloses a wide-temperature-range direct-driven servo valve which is composed of a valve body, a driving mechanism, a sensor and a controller, the controller is connected with the driving mechanism and the sensor through a high and low temperature resistant shielding cable and a special plug, and electronic elements are prevented from being damaged by high temperature in the valve body; the driving mechanism is flexibly formed according to the operation mode of the valve element, a wide-temperature-range rotary transformer is adopted as a sensor, a rotor and a motor are coaxial, non-contact high-precision position detection is achieved, and signals are transmitted to an external controller. The controller carries out accurate driving and feedback control on the motor according to a control signal and sensor feedback, accurate adjustment of the position of the valve element is guaranteed, and the stability and reliability of the system are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of servo valves, and particularly to a wide-temperature-range direct-drive servo valve. Background Art

[0002] In many fields with strict requirements for fluid control accuracy, such as industrial automation, aerospace, and high-end equipment manufacturing, as a core hydraulic control component, the performance of a direct-drive servo valve directly determines the control efficiency and operation reliability of the entire system. In order to pursue structural compactness, traditional direct-drive servo valves generally integrate electronic components directly inside the valve body. Although this design simplifies the layout, it has significant shortcomings in environmental adaptability.

[0003] Under high-temperature working conditions, it is difficult for the heat inside the valve body to dissipate effectively, and the heat continuously accumulates and conducts to the electronic components. The electrical characteristics of semiconductor materials, packaging materials, etc. of the electronic components deteriorate rapidly at high temperatures. For example, the on-resistance of transistors surges, the dielectric loss of capacitors increases, and the internal solder joints of chips are desoldered, directly causing circuit failure, resulting in the inability to transmit and execute servo valve control commands normally, and the system is at risk of paralysis.

[0004] In a low-temperature environment, problems such as reduced electron mobility inside electronic devices, shrinkage and embrittlement of circuit board substrates, increased brittleness of solder joints, delayed sensor signal transmission, unstable amplifier gain, and abnormal power output of drive circuits occur frequently, seriously interfering with the precise control of the servo valve and reducing its response speed and control accuracy; therefore, it is urgent to develop a wide-temperature-range direct-drive servo valve. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above technical deficiencies, and propose a wide-temperature-range direct-drive servo valve to solve the problems raised in the background art.

[0006] To achieve the above technical objectives, the technical solution of the present invention provides a wide-temperature-range direct-drive servo valve, including: a valve body, a drive mechanism, a sensor, and a controller. The drive mechanism is connected to the spool inside the valve body, and the sensor is mechanically connected to the drive mechanism; the controller is electrically connected to the sensor and the drive mechanism through a cable. The controller includes a processor and a power supply circuit, an execution circuit, a sensor input circuit, and a minimum system electrically connected thereto. The minimum system includes a clock circuit and a reset circuit. The execution circuit is electrically connected to the drive mechanism to control the position of the spool inside the valve body and feedback the state of the drive mechanism to the processor. The sensor is electrically connected to the sensor input circuit and obtains the state information of the spool through the connection between the drive mechanism and the spool.

[0007] Furthermore, the drive mechanism includes a motor, the sensor is a resolver, and both ends of the rotor of the motor are respectively connected to the rotor of the sensor and the spool.

[0008] Further, the driving mechanism includes a transmission mechanism and a motor. The two ends of the transmission mechanism are respectively connected to the rotor of the motor and the valve core. The motor drives the valve core to perform telescopic movement in the valve body through the transmission mechanism. The sensor is a resolver, and the rotor of the sensor is coaxially connected to the rotor of the motor.

[0009] Further, the execution circuit includes a motor drive circuit, a sampling circuit, and an analog / digital conversion circuit. The motor drive circuit and the sampling circuit are electrically connected to the motor. The motor drive circuit converts the instructions of the processor into electrical signals to drive the motor. After the sampling circuit collects the electrical signals during the operation of the motor, they are converted into digital signals through the analog / digital conversion circuit and fed back to the processor.

[0010] Further, the power supply circuit includes an isolated power supply module, a step-down module, a voltage stabilization module, and a tertiary power supply. The input end of the isolated power supply module is connected to an external power supply, and the output end is connected to the input end of the step-down module. The output end of the step-down module is connected to the input end of the voltage stabilization module. The output end of the voltage stabilization module is connected to the input end of the tertiary power supply. The output end of the tertiary power supply is connected to the power supply ends of the processor and the minimum system.

[0011] Further, the I / O port of the processor is connected to an externally expanded memory and a communication transceiver, and the input ends of the analog / digital conversion circuit are connected in parallel with external input signals.

[0012] Further, the motor is a three-phase motor, and its stator is wound with high-temperature-resistant materials.

[0013] Further, the cable is connected to the sensor and the driving mechanism through a plug, and the plug is made of high and low temperature resistant materials.

[0014] Compared with the prior art, the beneficial effects of the present invention include:

[0015] 1. The present invention connects the controller to the driving mechanism and the sensor through a cable and a special plug, effectively avoiding the direct damage of high / low temperature environments during the operation of the valve body to electronic components: In wide temperature range application scenarios, the temperature inside the valve body fluctuates greatly, and ordinary connection methods are likely to cause the performance of electronic components to decline or even be damaged due to overheating or temperature changes. The combination of high and low temperature resistant flexible shielded cables and special plug sockets can not only withstand extreme temperatures but also have good shielding performance, reducing external interference, ensuring stable signal transmission, and ensuring the stable operation of the servo valve in complex temperature environments, improving reliability and service life.

[0016] 2. The present invention replaces the magnetic encoder with a wide-temperature-range resolver. The rotor is coaxial with the motor, and the position signal cable seat transmits the signal to an external controller, achieving contactless high-precision detection. Under wide-temperature-range working conditions, the magnetic encoder is vulnerable to temperature effects, resulting in a decrease or even failure of the measurement accuracy. However, the wide-temperature-range resolver, with its wide-temperature-range adaptability and high-precision characteristics, can stably and accurately feedback the position information of the motor rotor, thereby accurately reflecting the position of the spool. At the same time, the contactless detection method avoids mechanical wear, reduces maintenance costs, and improves the reliability and stability of detection, providing a strong guarantee for the precise control of the servo valve in a wide-temperature-range environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of a wide-temperature-range direct-drive servo valve provided by the present invention;

[0018] Figure 2 is a schematic diagram of the controller composition of a wide-temperature-range direct-drive servo valve provided by the present invention; DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0020] Refer to Figure 1 , the present invention provides a wide-temperature-range direct-drive servo valve, which mainly consists of a valve body 1, a driving mechanism, a sensor 4 and a controller 5. The driving mechanism is tightly connected to the spool in the valve body 1. The sensor 4 is mechanically connected to the driving mechanism. The controller 5 is electrically connected to the sensor 4 and the driving mechanism through a cable 6 respectively. The cable 6 is connected to the sensor 4 through a plug, and the plug is made of high and low temperature resistant materials. In a wide-temperature-range environment, the plug made of high and low temperature resistant materials can effectively prevent problems such as plug loosening and poor contact caused by temperature changes, ensuring the stability and reliability of the signal transmission between the sensor 4 and the controller 5.

[0021] In practical applications, the driving mechanism has two composition methods. When the spool in the valve body 1 operates in a rotating manner, the driving mechanism only includes a motor 3, and the sensor 4 is a resolver. The two ends of the rotor of the motor 3 are directly connected to the rotor of the sensor 4 and the spool respectively. The motor 3 directly drives the spool to rotate, and at the same time, the resolver can accurately feedback the position information of the rotor of the motor 3 in real time, thereby reflecting the position of the spool.

[0022] When the spool in the valve body 1 operates in a telescopic manner, the drive mechanism consists of a transmission mechanism 2 and a motor 3. The two ends of the transmission mechanism 2 are respectively connected to the rotor of the motor 3 and the spool. The sensor 4 is also a resolver, and the rotor of the sensor 4 is coaxially connected to the rotor of the motor 3. The motor 3 drives the spool to expand and contract in the valve body 1 through the transmission mechanism 2. At the same time, the resolver is coaxially connected to the rotor of the motor 3 to feedback the position of the spool in the valve body 1.

[0023] Referring to Figure 2 , the controller 5 includes a processor 7, a power supply circuit 8, an execution circuit 9, a sensor input circuit, and a minimum system. The minimum system is composed of a clock circuit and a reset circuit, providing a basic guarantee for the stable operation of the processor 7.

[0024] The power supply circuit 8 specifically includes an isolation power supply module, a buck module, a voltage stabilization module, and a tertiary power supply. The input end of the isolation power supply module is connected to the external power input, and its output end is connected to the input end of the buck module. The buck module adjusts the voltage to an appropriate range, and its output end is then connected to the input end of the voltage stabilization module. The voltage stabilization module further stabilizes the voltage. Finally, the output end of the voltage stabilization module is connected to the input end of the tertiary power supply, and the output end of the tertiary power supply provides a stable and reliable power supply for the processor 7 and the minimum system. This power supply design can effectively cope with voltage fluctuations in a wide temperature range, ensuring that the system can be stably powered under various temperature conditions.

[0025] The execution circuit 9 includes a motor drive circuit, a sampling circuit, and an analog / digital conversion circuit. Both the motor drive circuit and the sampling circuit are electrically connected to the motor 3. The motor drive circuit is responsible for converting the instructions issued by the processor 7 into electrical signals to drive the motor 3 to rotate; the sampling circuit collects the electrical signals during the operation of the motor 3, such as current, voltage, etc., and then converts these analog signals into digital signals through the analog / digital conversion circuit and feedbacks them to the processor 7 so that the processor 7 can monitor and adjust the operation state of the motor 3 in real time.

[0026] The sensor input circuit is electrically connected to the sensor 4 for receiving the signals collected by the sensor 4. The I / O port of the processor 7 is connected to an external extended memory and a communication transceiver. The external extended memory is used to store important data such as fault information, and the communication transceiver realizes data communication between the controller 5 and the host computer.

[0027] To facilitate the understanding of the present invention, the following combines Figure 1 - Figure 2 to elaborate in detail on the working principle of this solution:

[0028] After the 24V power supply becomes effective, the controller 5 undergoes a power-on reset process of 200ms and then enters the initialization state. In the initialization state, the controller 5 reads the communication signal from the host computer and the control signal input externally. The control signal includes various forms of analog signals. The controller 5 will compare the status information sent by the host computer with the read analog information. If the two match, the controller 5 enters the control mode; if not, it reports the controller fault through the communication signal.

[0029] After entering the control mode, the controller 5 analyzes the detected control signal according to the set control period. According to a certain control law, it outputs the corresponding motor drive signal to drive the motor 3 to rotate, thereby driving the spool to adjust the hydraulic oil circuit. At the same time, the sampling circuit in the execution circuit 9 samples the three-phase current of the motor 3, converts it into a digital signal through the analog / digital conversion circuit and then feeds it back to the processor 7. The processor 7 performs the feedback control of the current loop. In addition, the sensor 4 (resolver) feeds back the position information of the spool, including phase and speed information. The processor 7 analyzes this information and performs the feedback control of speed and position on the output motor drive signal to achieve precise adjustment of the spool position.

[0030] During the power-on, periodic operation and maintenance of the controller 5, it comprehensively detects its own status. The detection contents include whether the power supply is normal three times, whether the control signal exceeds the range, whether the motor drive output is abnormal, etc. When it is detected that an abnormality occurs for three consecutive beats, it is determined that the controller 5, the resolver or the motor 3 is abnormal, and the controller 5 immediately enters the safety mode. In the safety mode, the controller 5 no longer responds to the control signals from communication and external analog quantity setting, and will store the fault information before and after the fault occurs through the external expansion memory. At the same time, the control of the motor is always set to invalid to ensure the safety of the system.

[0031] For the convenience of debugging, the controller 5 can be set to the maintenance mode through an external switch. In this mode, all the faults generated by the controller 5 can be set to invalid through the host computer. Technicians can read the information of the external expansion memory of the controller through the host computer to deeply analyze the faults, so as to quickly locate and solve the problems.

[0032] The specific implementation manners of the present invention described above do not constitute a limitation to the protection scope of the present invention. Any other corresponding changes and deformations made according to the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A wide-temperature-range direct-drive servo valve, comprising a valve body, a drive mechanism, a sensor and a controller, wherein the drive mechanism is connected to a spool in the valve body, and the sensor is mechanically connected to the drive mechanism; it is characterized in that: The controller is electrically connected to the sensor and the drive mechanism through a cable. The controller includes a processor and a power supply circuit, an execution circuit, a sensor input circuit, and a minimum system that are electrically connected to it. The minimum system includes a clock circuit and a reset circuit. The execution circuit is electrically connected to the drive mechanism to control the position of the spool in the valve body and feedback the state of the drive mechanism to the processor. The sensor is electrically connected to the sensor input circuit and obtains the state information of the spool through the connecting member between the drive mechanism and the spool.

2. The wide-temperature-range direct-drive servo valve according to claim 1, wherein: The drive mechanism includes a motor, the sensor is a resolver, and both ends of the rotor of the motor are respectively connected to the rotor of the sensor and the spool.

3. The wide-temperature-range direct-drive servo valve according to claim 1, wherein: The drive mechanism includes a transmission mechanism and a motor. Both ends of the transmission mechanism are respectively connected to the rotor of the motor and the spool. The motor drives the spool to perform telescopic movement in the valve body through the transmission mechanism. The sensor is a resolver, and the rotor of the sensor is coaxially connected to the rotor of the motor.

4. A wide-temperature-range direct-drive servo valve according to claim 2 or 3, characterized in that: The execution circuit includes a motor drive circuit, a sampling circuit, and an analog / digital conversion circuit. The motor drive circuit and the sampling circuit are electrically connected to the motor. The motor drive circuit converts the instructions of the processor into electrical signals to drive the motor. After the sampling circuit collects the electrical signals during the operation of the motor, they are converted into digital signals through the analog / digital conversion circuit and feedback to the processor.

5. The wide-temperature-range direct-drive servo valve according to claim 4, wherein: The power supply circuit includes an isolated power supply module, a buck module, a voltage stabilizing module, and a tertiary power supply. The input end of the isolated power supply module is connected to an external power supply, and the output end is connected to the input end of the buck module. The output end of the buck module is connected to the input end of the voltage stabilizing module. The output end of the voltage stabilizing module is connected to the input end of the tertiary power supply. The output end of the tertiary power supply is connected to the power supply terminals of the processor and the minimum system.

6. The wide-temperature-range direct-drive servo valve according to claim 5, wherein: The I / O port of the processor is connected to an externally expanded memory and a communication transceiver. The input end of the analog / digital conversion circuit is connected in parallel with an external input signal.

7. The wide-temperature-range direct-drive servo valve according to claim 6, characterized in that: The motor is a three-phase motor, and its stator is wound with high-temperature resistant materials.

8. A wide-temperature-range direct-drive servo valve according to claim 7, characterized in that: The cable is connected to the sensor and the drive mechanism through a plug, and the plug is made of materials resistant to high and low temperatures.

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