A limit protection device for a valve actuator

Abstract

The present invention relates to the field of mechanical engineering, and particularly to a limit protection device for a valve actuator, which includes a valve actuator for driving the opening and closing of a valve, a mounting bracket, and a main body of the limit protection device. A driving member is provided inside the valve actuator. The main body of the limit protection device includes: a housing and a limit switch unit. The interior of the housing is divided into a sensor compartment, a control compartment, and a braking compartment; a detection unit is installed on the output shaft, and a control unit is installed in the control compartment. The control unit is used to receive the angle and displacement data detected in real time by the detection unit, and perform redundant verification based on the angle and displacement data detected in real time; a self-locking unit is installed in the braking compartment, and a warning unit is installed on the outer side wall of the housing. The warning unit is used to give a warning according to the judgment result of the control unit. The present invention solves the deficiencies of traditional limit protection devices in terms of safety, adaptability, stability, and operability, and significantly improves the operation reliability and maintenance efficiency of the valve actuator.

Description

Technical Field

[0001] The present invention relates to the field of mechanical engineering, and particularly to a limit protection device for a valve actuator. Background Art

[0002] In an industrial automation system, the limit protection device of a valve actuator is a core component to ensure the precise control and safe operation of the valve opening and closing actions. Traditional limit protection devices mostly use single mechanical limit or electronic sensors to achieve position detection. For example, through mechanical stoppers cooperating with contact limit switches, or relying on a single signal source such as Hall sensors. However, such designs have many defects in practical applications:

[0003] Insufficient safety: Mechanical limit switches rely on rigid contact triggering. When the valve actuator suddenly stops at the limit position, it is easy to generate impact loads, resulting in wear or even fracture of transmission components (such as gears, couplings). And a single electronic sensor is prone to signal distortion in high-temperature, vibration or electromagnetic interference environments, causing misjudgment or missed judgment, and there is a risk of overtravel.

[0004] Lack of redundancy: Existing devices usually lack a multi-level detection mechanism. Once the main sensor fails, the system has no backup detection unit to take over, which may lead to valve out of control. For example, after the encoder fails, it is impossible to continue monitoring the displacement through redundant sensors, and the control system loses the basis for protection logic judgment.

[0005] Limited dynamic adjustment ability: Most devices use fixed threshold limits and cannot dynamically adjust the deceleration range according to load changes (such as pipeline pressure fluctuations, valve jamming), resulting in frequent triggering of hard limits or premature braking, reducing the operating efficiency.

[0006] In view of the above problems, although some improvement schemes have proposed dual sensors or buffer structures, they still have not systematically integrated functions such as multi-level limit and redundant control. Therefore, there is an urgent need for a limit protection device that integrates multi-level limit protection, intelligent diagnosis and rapid maintenance to improve the comprehensive performance of the valve actuator in a complex industrial environment. Summary of the Invention

[0007] To solve the above problems, the present invention provides a limit protection device for a valve actuator. Through designs such as multi-level limit protection, redundant detection, intelligent heat dissipation, power redundancy, quick installation and emergency unlocking, it solves the deficiencies of traditional limit protection devices in terms of safety, adaptability, stability and operability, and significantly improves the operating reliability and maintenance efficiency of the valve actuator.

[0008] To achieve the above object, the technical solution of the present invention is as follows: A limit protection device for a valve actuator, comprising a valve actuator for driving the opening and closing of a valve, a mounting bracket, and a main body of the limit protection device. A driving member is provided inside the valve actuator. The main body of the limit protection device is mounted on one side of the output shaft of the driving member through the mounting bracket. The main body of the limit protection device includes: a housing and a limit switch unit. The interior of the housing is divided into a sensor compartment, a control compartment, and a braking compartment;

[0009] A detection unit is mounted on the output shaft;

[0010] A control unit is mounted in the control compartment;

[0011] The limit switch unit includes a first limit switch and a second limit switch;

[0012] A self-locking unit is mounted in the braking compartment. The self-locking unit includes an electromagnetic brake and a mechanical latch. The electromagnetic brake is coaxially and fixedly connected to the output shaft of the driving member, and the mechanical latch is linked with the mechanical limit switch;

[0013] An early warning unit is mounted on the outer side wall of the housing. The early warning unit is used to give an early warning according to the judgment result of the control unit;

[0014] When the output shaft displacement data detected in real time by the detection unit reaches 90% of the preset limit value, the control unit triggers the first limit switch to perform electronic limit deceleration;

[0015] If the displacement data continues to increase and reaches 100% of the preset limit value, the control unit triggers the second limit switch to generate a mechanical hard limit signal, and the control unit synchronously starts the electromagnetic brake and the mechanical latch of the self-locking unit;

[0016] The early warning unit sends different early warning signals according to the comparison result between the real-time detection data of the detection unit and the preset limit value. [[ID=2...]]

[0017] Further, the detection unit includes an encoder and a magnetic grating sensor. The encoder is mounted at one end of the output shaft of the driving member, and the magnetic grating sensor is embedded in the side wall of the output shaft of the driving member. The encoder and the magnetic grating sensor are used to detect the rotation angle and linear displacement of the output shaft of the driving member in real time;

[0018] The control unit includes a controller and a dynamic threshold storage module. The controller and the dynamic threshold storage module are used to receive the rotation angle and linear displacement data detected in real time by the detection unit, and perform redundant verification according to the real-time detected angle and displacement data; <00000...]]

[0019] The first limit switch is an electronic limit switch, and the first limit switch is mounted in the safety buffer area of the output shaft. The second limit switch is a mechanical limit switch, and the second limit switch is mounted at the stroke limit position of the output shaft;

[0020] The warning unit includes an indicator light and a buzzer. The indicator light is used to flash and emit lights of different colors to indicate different warning reminders, and the buzzer is used to emit different alarm sounds. Both the indicator light and the buzzer are signal-connected to the controller. When the controller determines that the angle detected in real time is different from the preset limit value in the data, the warning unit emits an audible and visual alarm signal.

[0021] Further, the dynamic threshold storage module is built-in with a self-learning algorithm. The self-learning algorithm automatically corrects the limit threshold by analyzing the displacement fluctuations of the valve actuator in N consecutive working cycles. The correction formula is:

[0022] ;

[0023] Where is the historical displacement standard deviation, is the environmental temperature compensation coefficient.

[0024] Further, partition boards are installed between the compartments inside the housing, and the partition boards are electromagnetic shielding partition boards.

[0025] Further, an active heat dissipation component is provided in the sensor compartment of the housing. The active heat dissipation component includes a fan and a temperature sensor. Both the fan and the temperature sensor are fixedly connected to the inner side wall of the housing corresponding to the sensor compartment. A directional air duct is provided on the side wall of the housing corresponding to the sensor compartment. Both the fan and the temperature sensor are signal-connected to the controller, and the controller dynamically adjusts the heat dissipation intensity of the fan according to the temperature data monitored by the temperature sensor in real time.

[0026] Further, adjustable guide vanes are provided in the directional air duct. The guide vanes are connected to the controller, and the controller dynamically adjusts the angle of the guide vanes according to the data of the temperature sensor, so as to adjust the heat dissipation air flow path.

[0027] Further, a main power supply module and a backup power supply module are installed in the control compartment. Both the main power supply module and the backup power supply module use super capacitors. The backup power supply module is connected in parallel with the main power supply. When the main power supply is powered off, the backup power supply module is automatically switched.

[0028] Further, it also includes a remote communication module. The remote communication module is signal-connected to an intelligent device, and the remote communication module is used to transmit the data of the detection unit, the status information of the control unit, and the alarm signal of the warning unit to the intelligent device in real time.

[0029] Further, the mounting bracket is of a U-shaped groove structure. The opening of the U-shaped groove faces the output shaft side of the driving part. A plurality of uniformly distributed mounting holes are provided on both side walls of the mounting bracket, and the mounting holes are used to fix the mounting bracket on the output shaft of the driving part through fasteners;

[0030] The bottom of the U-shaped groove of the mounting bracket is provided with a positioning groove and a guiding inclined surface, and the side wall of the main body shell of the limit protection device is provided with a slider matching the positioning groove, and the slider is slidably matched with the positioning groove.

[0031] Furthermore, it further includes an emergency unlocking unit, which includes a manual knob and a mechanical unlocking link. The manual knob penetrates through the side wall of the shell and is linked with the mechanical lock, and the mechanical unlocking link is provided with a force-limiting spring assembly;

[0032] When the mechanical lock is abnormally locked, rotate the manual knob, and drive the mechanical unlocking link through the force-limiting spring assembly, so as to release the locked state of the mechanical lock.

[0033] The technical principle of the above solution is as follows: Through a multi-level limit protection mechanism (electronic limit deceleration + mechanical hard limit) and redundant detection technology (encoder + magnetic grating sensor), the rotation angle and linear displacement of the output shaft are monitored in real time to ensure the limit accuracy and safety. The dynamic threshold storage module dynamically corrects the limit threshold through a self-learning algorithm to adapt to different working conditions and environmental changes. The interior of the shell is divided into a sensor compartment, a control compartment and a braking compartment. The compartments are isolated from interference by electromagnetic shielding partitions. The sensor compartment is provided with an active heat dissipation assembly (fan + temperature sensor + adjustable guide vane), and the heat dissipation intensity is dynamically adjusted according to the real-time temperature. The control compartment is equipped with a main power supply and a super capacitor backup power supply, which are automatically switched when the power is off to ensure the continuous operation of the system. The remote communication module realizes the real-time transmission of data to the intelligent device, supporting remote monitoring and instruction issuing. The mounting bracket adopts a U-shaped groove structure, and the quick installation is realized through the sliding fit of the slider and the positioning groove. The emergency unlocking unit (manual knob + mechanical unlocking link + force-limiting spring assembly) provides a manual unlocking function when the mechanical lock is abnormally locked, avoiding overload damage.

[0034] The following beneficial effects can be obtained by adopting the above solution:

[0035] 1. Multi-level protection improves safety: Traditional limit protection devices usually only rely on a single limit switch (such as a mechanical limit switch). When the output shaft approaches the limit position, there is a lack of a buffering mechanism, and it is easy to cause over-limit operation due to inertia or misoperation, which may lead to equipment damage or safety accidents.

[0036] In this solution, through the "electronic deceleration - mechanical hard limit" coordination mechanism, the risk of the output shaft exceeding the limit is effectively avoided, and the safety of the equipment is significantly improved. This multi-level protection mechanism significantly reduces the risk of the equipment running over the limit and improves the safety of the system.

[0037] 2. Redundant detection and dynamic adaptation: Traditional detection units usually only rely on a single sensor, and the detection accuracy is greatly affected by the environment, and the limit threshold cannot be dynamically adjusted, resulting in poor limit protection effect under complex working conditions (such as temperature change, mechanical wear).

[0038] This solution adopts a redundant detection design of an encoder and a magnetic grating sensor to improve the detection accuracy through dual-sensor data verification. At the same time, the dynamic threshold storage module incorporates a self-learning algorithm that analyzes the displacement fluctuations (standard deviation ) during N consecutive working cycles of the valve actuator, and combines with the environmental temperature compensation coefficient to dynamically correct the limit threshold. This design enables the system to adapt to different working conditions and environmental changes, and extends the service life of the equipment.

[0039] 3. Intelligent heat dissipation and electromagnetic isolation: The traditional sensor compartment lacks an effective heat dissipation design, and the sensor accuracy decreases in high-temperature environments; at the same time, there is a lack of electromagnetic shielding measures between functional units, and signal transmission is vulnerable to interference, affecting the system stability.

[0040] This solution sets up an active heat dissipation component (fan + temperature sensor + adjustable diversion vane) in the sensor compartment, dynamically adjusts the heat dissipation intensity and air flow path according to the real-time temperature, and ensures that the detection unit works in a constant-temperature environment. In addition, electromagnetic shielding partitions are installed between compartments inside the housing to effectively isolate electromagnetic interference and ensure the stability of signal transmission and detection accuracy.

[0041] 4. High reliability and continuous operation: This solution is equipped with a main power supply module and a supercapacitor backup power supply module in the control compartment. When the main power supply is cut off, it automatically switches to the backup power supply to ensure the continuous operation of the system. In addition, the remote communication module transmits detection data, control status, and warning signals to intelligent devices in real time, supports remote monitoring and instruction issuance, reduces the cost of manual intervention, and improves the intelligent level of the system.

[0042] 5. Quick installation and general adaptability: This solution adopts a modular design and a U-shaped mounting bracket. The two side walls of the bracket are provided with evenly distributed mounting holes to adapt to a variety of valve actuators. The bottom of the U-shaped groove of the mounting bracket is provided with a positioning groove and a guiding inclined surface. The slider of the main body housing of the limit protection device is slidably matched with the positioning groove, which simplifies the alignment and installation process, and the installation efficiency is increased by more than 50%, suitable for rapid deployment in industrial sites.

[0043] 6. Emergency safety guarantee: Compared with the existing technology where the mechanical lock cannot be manually unlocked when it is abnormally locked, this solution provides an emergency unlocking unit, which realizes safe unlocking through a manual knob and a force-limiting spring assembly, avoids overload damage, and ensures controllability under extreme faults.

[0044] The additional aspects and advantages of the present invention will be partially given in the following description, partially will become apparent from the following description, or be understood through the practice of the present invention. Brief Description of the Drawings

[0045] Figure 1 It is the front view of the embodiment of the limit protection device for the valve actuator of the present invention;

[0046] Figure 2 Isometric view of the limit protection device embodiment of the valve actuator of the present invention;

[0047] Figure 3 Explosion diagram of the limit protection device embodiment of the valve actuator of the present invention;

[0048] Figure 4 Frame diagram of the limit protection device embodiment of the valve actuator of the present invention.

[0049] Reference numerals in the accompanying drawings of the specification include: 1, driving member; 101, output shaft; 2, housing; 201, sensor compartment; 202, control compartment; 203, braking compartment; 3, mounting bracket; 301, positioning groove; 302, mounting hole; 4, partition. Detailed implementation manners

[0050] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0051] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0052] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installation", "connection", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0053] The following is a further detailed description through specific implementation manners:

[0054] Embodiment 1:

[0055] As shown in the appended Figures 1 to 4As shown in the figure: A limit protection device for a valve actuator, including a valve actuator for driving the opening and closing of a valve, a mounting bracket 3, and a main body of the limit protection device. A driving member 1 is provided inside the valve actuator. In this embodiment, the driving member 1 is a driving motor. The main body of the limit protection device is mounted on one side of the output shaft 101 of the driving member 1 through the mounting bracket 3. The main body of the limit protection device includes: a housing 2 and a limit switch unit. The interior of the housing 2 is divided into a sensor compartment 201, a control compartment 202, and a braking compartment 203. The mounting bracket 3 is of a U-shaped groove structure. The opening of the U-shaped groove faces one side of the output shaft 101 of the driving member 1. A plurality of uniformly distributed mounting holes 302 are provided on both side walls of the mounting bracket 3. The mounting holes 302 are used to fix the mounting bracket 3 on the output shaft 101 of the driving member 1 through fasteners (in this embodiment, socket head cap screws are selected). A positioning groove 301 and a guiding inclined surface are provided at the bottom of the U-shaped groove of the mounting bracket 3. A sliding block (not shown in the figure) matching the positioning groove 301 is provided on the inner side wall of the housing 2. The sliding block is in sliding fit with the positioning groove 301.

[0056] A detection unit is mounted on the output shaft 101. The detection unit includes an encoder (in this embodiment, an incremental photoelectric encoder is selected, model example: Omron E6B2-CWZ6C) and a magnetic grating sensor (in this embodiment, a magnetic grating ruler and a magnetic head sensor are selected, model example: Renishaw RGH22 series). The encoder is mounted at one end of the output shaft 101 of the driving member 1. The magnetic grating sensor is embedded in the side wall of the output shaft 101 of the driving member 1. The encoder and the magnetic grating sensor are used to detect the rotation angle and linear displacement of the output shaft 101 of the driving member 1 in real time.

[0057] A control unit is mounted in the control compartment 202. The control unit includes a controller and a dynamic threshold storage module. The controller and the dynamic threshold storage module are used to receive the rotation angle and linear displacement data detected by the detection unit in real time, and perform redundancy verification according to the angle and displacement data detected in real time. The dynamic threshold storage module is built-in with a self-learning algorithm. The self-learning algorithm automatically corrects the limit threshold by analyzing the displacement fluctuation of the valve actuator in N consecutive working cycles. The correction formula is:

[0058] ;

[0059] where is the historical displacement standard deviation, is the environmental temperature compensation coefficient.

[0060] A main power module and a backup power module are mounted in the control compartment 202. Both the main power module and the backup power module use supercapacitors (in this embodiment, 24V supercapacitors are selected). The backup power module is connected in parallel with the main power. When the main power is cut off, the backup power module is automatically switched.

[0061] The limit switch unit includes a first limit switch and a second limit switch. The first limit switch is an electronic limit switch and is installed in the safety buffer area of the output shaft 101. The second limit switch is a mechanical limit switch and is installed at the stroke limit position of the output shaft 101. In this embodiment, the first limit switch selects a Hall sensor (such as the selected model: Honeywell SS49E), and by detecting the magnetic field change of the magnetic grating sensor embedded on the side wall of the output shaft 101, it real-time feeds back the position signal to the controller. When the displacement of the output shaft 101 reaches 90% of the preset limit value, the Hall sensor triggers an electronic limit deceleration signal. The second limit switch selects a roller-type lever limit switch (such as the selected model: Omron Z-15GW22-B). When the displacement of the output shaft 101 reaches 100% of the preset limit value, the output shaft 101 touches and presses the roller lever of the mechanical limit switch, triggering a mechanical hard limit signal, and at the same time, the mechanical latch is linked to lock the position of the output shaft 101.

[0062] A self-locking unit is installed in the braking cabin 203. The self-locking unit includes an electromagnetic brake and a mechanical latch. The electromagnetic brake is coaxially and fixedly connected to the output shaft 101 of the driving member 1, and the mechanical latch is linked with the mechanical limit switch.

[0063] An early warning unit is installed on the outer side wall of the housing 2. The early warning unit is used to give an early warning according to the judgment result of the control unit. The early warning unit includes an indicator light and a buzzer. The indicator light is used to flash and emit lights of different colors to represent different early warning reminders, and the buzzer is used to emit different alarm sounds.

[0064] When the displacement data of the output shaft 101 detected in real time by the detection unit reaches 90% of the preset limit value, the control unit triggers the first limit switch for electronic limit deceleration.

[0065] If the displacement data continues to increase and reaches 100% of the preset limit value, the control unit triggers the second limit switch to generate a mechanical hard limit signal, and the control unit synchronously starts the electromagnetic brake and the mechanical latch of the self-locking unit.

[0066] The early warning unit sends different early warning signals according to the comparison result between the real-time detection data of the detection unit and the preset limit value. Among them, both the indicator light and the buzzer are signal-connected to the controller. When the controller judges that the real-time detected angle and position data are different from the preset limit value, the early warning unit issues an audible and visual alarm signal.

[0067] [[ID=!8]]The specific implementation process is as follows: [[ID=2!]]

[0068] [[ID=2!]](1)Installation process:

[0069] Manually fix the mounting bracket 3 on the output shaft 101 of the driving part 1 with bolts, ensuring that the opening of the U-shaped groove faces the output shaft 101 side. Use a torque wrench to tighten the bolts according to the preset torque value (20 N·m is selected in this embodiment) to ensure the stability of the mounting bracket 3. Align the slider of the main body of the limit protection device with the positioning groove 301 of the mounting bracket 3 and slide it to the installation position along the guiding inclined plane. Use fasteners (inner hexagon screws are selected in this embodiment) to fix the main body of the limit protection device on the mounting bracket 3.

[0070] Install the encoder at one end of the output shaft 101 of the driving part 1, ensuring that the encoder is coaxial with the output shaft 101. Embed the magnetic grating sensor on the side wall of the output shaft 101, ensuring that the positions of the magnetic grating sensor and the encoder correspond to ensure the detection accuracy.

[0071] Connect the main power module and the standby power module to the control unit to ensure stable power supply. Check whether the wiring of the power module is correct and use a multimeter to measure the voltage to ensure that the output voltages of the main power module and the standby power module are both 24V.

[0072] (2) Debugging process:

[0073] Start the control unit to perform system initialization and self-check. Check whether the signal outputs of the encoder and the magnetic grating sensor are normal to ensure that the detection unit can collect the rotation angle and linear displacement data of the output shaft 101 in real time.

[0074] According to the working requirements of the valve actuator, set the initial limit threshold (±90° for the rotation angle limit value and ±50mm for the linear displacement limit value are selected in this embodiment). Input the initial limit threshold into the control unit .

[0075] Let the valve actuator perform N consecutive working cycles (N = 10 is selected in this embodiment), and the dynamic threshold storage module records the displacement data of each working cycle. Calculate the historical displacement standard deviation :

[0076] ;

[0077] Among them, is the displacement data of the th working cycle, is times the average displacement of the working cycle.

[0078] According to the environmental unread compensation coefficient (0.5 is selected in this embodiment) , calculate the corrected limit threshold :

[0079] ;

[0080] For example, if =50mm, =2mm, then:

[0081] mm;

[0082] The corrected limit threshold Stored in the dynamic threshold storage module.

[0083] (3) Usage process:

[0084] When the valve actuator is working, the detection unit monitors the rotation angle and linear displacement of the output shaft 101 in real time, and the encoder and magnetic grating sensor transmit the collected data to the control unit. When the displacement data of the output shaft 101 detected in real time by the detection unit reaches 90% of the preset limit value, the control unit sends a deceleration signal to the first limit switch. After receiving the deceleration instruction, the first limit switch sends a signal to reduce the speed to the drive motor of the valve actuator. The drive motor of the valve actuator gradually reduces the speed of the output shaft 101 according to the deceleration signal, for example, from 100% of the rated speed to 30% of the rated speed. During the deceleration process, the detection unit continues to monitor the displacement data of the output shaft 101 in real time, and feeds the data back to the control unit. The control unit dynamically adjusts the deceleration amplitude according to the real-time displacement data to ensure that the output shaft 101 decelerates smoothly.

[0085] If the displacement data continues to increase and reaches 100% of the preset limit value, the control unit triggers the second limit switch to generate a mechanical hard limit signal. After receiving the hard limit command, the second limit switch triggers the mechanical limit mechanism. The control unit simultaneously activates the electromagnetic brake of the self-locking unit, which is coaxially fixedly connected to the output shaft 101 of the driver 1 and immediately brakes the output shaft 101. The mechanical lock is linked to the mechanical limit switch, and the mechanical lock locks the position of the output shaft 101 to prevent the output shaft 101 from continuing to move. The drive motor of the valve actuator stops running, and the output shaft 101 comes to a complete stop.

[0086] The early warning unit sends different warning signals based on the comparison of the detection unit's real-time detection data with the preset limit value. For example, when the displacement data reaches 90% of the preset limit value, the indicator light flashes yellow and the buzzer sounds intermittently. When the displacement data reaches 100% of the preset limit value, the indicator light flashes red and the buzzer sounds continuously. The operator takes appropriate measures based on the warning signal, such as checking the operating status of the valve actuator or adjusting operating parameters.

[0087] When the main power supply module is powered off, the backup power supply module automatically switches to ensure the continuous operation of the limit protection device. The control unit records the power supply switching event and issues a power failure alarm through the warning unit.

[0088] Embodiment 2:

[0089] The difference from Embodiment 1 is that partition plates 4 are installed between the compartments inside the housing 2. The partition plates 4 are electromagnetic shielding partition plates 4, and the partition plates 4 are made of a metal material with high magnetic permeability (galvanized steel plate is selected in this embodiment).

[0090] The specific implementation process is as follows: In this embodiment, the thickness of the partition plate 4 is 1.5 mm, which can effectively shield electromagnetic interference in the frequency range of 10 kHz to 1 GHz, and a conductive coating is applied on the surface to enhance the electromagnetic shielding effect. A conductive sealing strip is installed between the contact surfaces of the partition plate 4 and the housing 2 to ensure the continuity of electromagnetic shielding.

[0091] When the valve actuator is working, the electromagnetic shielding partition plate 4 effectively isolates the electromagnetic interference between the compartments. The detection unit, the control unit, and the self-locking unit work together in a low electromagnetic interference environment to ensure the stability and reliability of the system.

[0092] Embodiment 3:

[0093] The difference from Embodiment 2 is that an active heat dissipation component is provided in the sensor compartment 201 of the housing 2. The active heat dissipation component includes a fan and a temperature sensor. Both the fan and the temperature sensor are fixedly connected to the inner side wall of the housing 2 corresponding to the sensor compartment 201. A directional air duct is provided on the side wall of the housing 2 corresponding to the sensor compartment 201. Both the fan and the temperature sensor are signal-connected to the controller, and the controller dynamically adjusts the heat dissipation intensity of the fan according to the temperature data real-time monitored by the temperature sensor.

[0094] Adjustable flow guiding vanes are provided in the directional air duct. The flow guiding vanes are connected to the controller, and the controller dynamically adjusts the angle of the flow guiding vanes according to the data of the temperature sensor, thereby adjusting the heat dissipation air flow path.

[0095] The specific implementation process is as follows: The temperature sensor real-time monitors the temperature in the sensor compartment 201 and feeds the data back to the controller. In this embodiment, the temperature sensor collects temperature data once per second and transmits the data to the controller. The controller dynamically adjusts the heat dissipation intensity of the fan according to the data of the temperature sensor.

[0096] That is, when the temperature is lower than 30 °C, the fan runs at a low speed. When the temperature reaches 30 °C to 40 °C, the fan runs at a medium speed. When the temperature is higher than 40 °C, the fan runs at a high speed. For example, if the temperature sensor detects that the temperature is 35 °C, the controller adjusts the fan speed to medium speed.

[0097] Meanwhile, the controller dynamically adjusts the angle of the deflector blades according to the data of the temperature sensor to adjust the heat dissipation air flow path. When the temperature distribution in the sensor compartment 201 is uneven, the controller adjusts the angle of the deflector blades to make more air flow to the high-temperature area. For example, if the temperature on the left side is higher, the controller adjusts the angle of the deflector blades to 30° to make more air flow to the left side.

[0098] Specific examples are as follows: Assume that the temperature on the left side in the sensor compartment 201 is 45°C and the temperature on the right side is 35°C: The controller adjusts the fan speed to high speed. The controller adjusts the angle of the deflector blades to 30° to make more air flow to the left side. After heat dissipation, the temperature on the left side drops to 40°C and the temperature on the right side drops to 33°C.

[0099] The active heat dissipation component ensures that the temperature in the sensor compartment 201 is maintained within a reasonable range to avoid the influence of high temperature on the detection units (encoder and magnetic grating sensor). For example, the encoder and magnetic grating sensor work at an appropriate temperature to improve the detection accuracy. The controller dynamically adjusts the heat dissipation intensity of the fan and the angle of the deflector blades according to the data of the temperature sensor to ensure uniform temperature distribution in the sensor compartment 201. For example, the controller avoids the temperature in the sensor compartment 201 being too high or too low by adjusting the heat dissipation intensity in real time.

[0100] When the temperature sensor detects abnormal temperature, the controller issues an alarm through the warning unit. If the temperature exceeds 50°C, the indicator light of the warning unit flashes red light and the buzzer emits a continuous alarm sound.

[0101] Embodiment 4:

[0102] The difference from Embodiment 3 is that it further includes a remote communication module (a 4G communication module is selected in this embodiment), the remote communication module is signal-connected to intelligent devices (such as mobile phones, computers, and tablets, etc.), and the remote communication module is used to transmit the data of the detection unit, the status information of the control unit, and the alarm signal of the warning unit to the intelligent devices in real time.

[0103] The specific implementation process is as follows: Start the controller and the remote communication module, perform initialization and self-check, check whether the signal connection of the communication module is normal, and ensure that it can establish communication with the intelligent device. Open the monitoring software on the intelligent device to observe whether it can receive the data of the detection unit, the status information of the control unit, and the alarm signal of the warning unit. Send a control instruction on the intelligent device to observe whether the controller can execute the instruction.

[0104] The remote communication module transmits the data of the detection unit, the status information of the control unit, and the alarm signal of the warning unit to the intelligent device in real time, and the operator monitors the working status of the valve actuator through the intelligent device in real time. At the same time, the operator sends a control instruction through the intelligent device to remotely control the working status of the valve actuator.

[0105] Specifically, for example, the operator can monitor the working status of the valve actuator in real time through a mobile phone: when the displacement reaches 90% of the preset limit value, the mobile phone receives an alarm prompt, and the operator remotely sends a deceleration command. When the displacement reaches 100% of the preset limit value, the mobile phone receives a system stop prompt, and the operator remotely checks the system status.

[0106] Embodiment 5:

[0107] The difference from Embodiment 4 is that it further includes an emergency unlocking unit (not shown in the figure). The emergency unlocking unit includes a manual knob and a mechanical unlocking link. The manual knob penetrates the side wall of the housing 2 and is linked with the mechanical lock. The mechanical unlocking link is provided with a force-limiting spring assembly; a pin shaft is used to fix the mechanical unlocking link to the manual knob and the mechanical lock to ensure that the mechanical unlocking link can rotate freely.

[0108] When the mechanical lock is abnormally locked, rotate the manual knob, and drive the mechanical unlocking link through the force-limiting spring assembly, thereby releasing the locked state of the mechanical lock.

[0109] The specific implementation process is as follows: Under normal circumstances, the mechanical lock is automatically controlled by the control unit, and there is no need to use the emergency unlocking unit. When the mechanical lock is abnormally locked, the operator rotates the manual knob, drives the mechanical unlocking link through the force-limiting spring assembly, and releases the locked state of the mechanical lock.

[0110] That is, the operator rotates the manual knob clockwise by 90°, and the force-limiting spring assembly starts to compress. The mechanical unlocking link drives the mechanical lock to unlock, and the output shaft 101 returns to the free state.

[0111] During the emergency unlocking process, the force-limiting spring assembly limits the operating force to prevent excessive force from damaging the mechanical lock. When the operating force exceeds 10 N·m, the force-limiting spring assembly compresses, and the operator feels the resistance and stops rotating the manual knob.

[0112] Obviously, the above embodiments are only examples clearly described and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. A limit protection device for a valve actuator, comprising a valve actuator for driving the opening and closing of a valve, a mounting bracket (3), and a limit protection device main body. A driving member (1) is provided in the valve actuator. The limit protection device main body is mounted on one side of the output shaft (101) of the driving member (1) through the mounting bracket (3), and is characterized in that, The main body of the limit protection device includes: a housing (2) and a limit switch unit. The interior of the housing (2) is divided into a sensor compartment (201), a control compartment (202), and a braking compartment (203); A detection unit is installed on the output shaft (101). The detection unit includes an encoder and a magnetic grating sensor. The encoder is installed at one end of the output shaft (101) of the driving member (1), and the magnetic grating sensor is embedded in the side wall of the output shaft (101) of the driving member (1). The encoder and the magnetic grating sensor are used to detect the rotation angle and linear displacement of the output shaft (101) of the driving member (1) in real time; A control unit is installed in the control compartment (202). The control unit includes a controller and a dynamic threshold storage module. The controller and the dynamic threshold storage module are used to receive the rotation angle and linear displacement data detected by the detection unit in real time, and perform redundancy verification based on the angle and displacement data detected in real time; The limit switch unit includes a first limit switch and a second limit switch. The first limit switch is an electronic limit switch, and the first limit switch is installed in the safe buffer area of the output shaft (101). The second limit switch is a mechanical limit switch, and the second limit switch is installed at the stroke limit position of the output shaft (101); A self-locking unit is installed in the braking compartment (203). The self-locking unit includes an electromagnetic brake and a mechanical latch. The electromagnetic brake is coaxially and fixedly connected to the output shaft (101) of the driving member (1), and the mechanical latch is linked with the mechanical limit switch; An early warning unit is installed on the outer side wall of the housing (2). The early warning unit is used to give an early warning according to the judgment result of the control unit; When the displacement data of the output shaft (101) detected by the detection unit in real time reaches 90% of the preset limit value, the control unit triggers the first limit switch to perform electronic limit deceleration; When the displacement data continues to increase and reaches 100% of the preset limit value, the control unit triggers the second limit switch to generate a mechanical hard limit signal, and the control unit synchronously starts the electromagnetic brake and the mechanical latch of the self-locking unit; The early warning unit sends different early warning signals according to the comparison result between the real-time detection data of the detection unit and the preset limit value. The early warning unit includes an indicator light and a buzzer. The indicator light is used to flash and emit different colors of light to represent different early warning reminders, and the buzzer is used to emit different alarm sounds. Both the indicator light and the buzzer are signal-connected to the controller. When the controller judges that the angle and position data detected in real time are different from the preset limit value, the early warning unit issues an audible and visual alarm signal.

2. The limit protection device for a valve actuator according to claim 1, characterized in that, The dynamic threshold storage module is built-in with a self-learning algorithm. The self-learning algorithm automatically corrects the limit threshold by analyzing the displacement fluctuations of the valve actuator in N consecutive working cycles. The correction formula is: ； wherein is the historical displacement standard deviation, is the environmental temperature compensation coefficient.

3. The limit protection device of the valve actuator according to claim 2, characterized in that, Partition plates (4) are installed between the compartments inside the housing (2). The partition plates (4) are electromagnetic shielding partition plates (4).

4. The limit protection device of the valve actuator according to claim 3, characterized in that, An active heat dissipation component is provided in the sensor compartment (201) of the outer shell (2). The active heat dissipation component includes a fan and a temperature sensor. Both the fan and the temperature sensor are fixedly connected to the inner side wall of the corresponding outer shell (2) of the sensor compartment (201). A directional air duct is provided on the side wall of the corresponding outer shell (2) of the sensor compartment (201). Both the fan and the temperature sensor are signal-connected to a controller, and the controller dynamically adjusts the heat dissipation intensity of the fan according to the temperature data real-time monitored by the temperature sensor.

5. The limit protection device of the valve actuator according to claim 4, characterized in that, An adjustable deflector blade is provided in the directional air duct. The deflector blade is connected to the controller, and the controller dynamically adjusts the angle of the deflector blade according to the data of the temperature sensor, thereby adjusting the heat dissipation air flow path.

6. The limit protection device for a valve actuator according to claim 5, characterized in that, A main power module and a backup power module are installed in the control compartment (202). Both the main power module and the backup power module use super capacitors. The backup power module is connected in parallel with the main power supply. When the main power supply is powered off, the backup power module is automatically switched.

7. The limit protection device for a valve actuator according to claim 6, characterized in that, It also includes a remote communication module. The remote communication module is signal-connected to an intelligent device, and the remote communication module is used to transmit the data of the detection unit, the status information of the control unit, and the alarm signal of the warning unit to the intelligent device in real time.

8. The limit protection device of the valve actuator according to claim 7, characterized in that, The mounting bracket (3) is of a U-shaped groove structure. The opening of the U-shaped groove faces the side of the output shaft (101) of the driving member (1). A plurality of uniformly distributed mounting holes (302) are provided on both side walls of the mounting bracket (3). The mounting holes (302) are used to fix the mounting bracket (3) on the output shaft (101) of the driving member (1) through fasteners; A positioning groove (301) and a guiding inclined surface are provided at the bottom of the U-shaped groove of the mounting bracket (3). A sliding block matching the positioning groove (301) is provided on the side wall of the main body shell (2) of the limit protection device. The sliding block is in sliding fit with the positioning groove (301).

9. The limit protection device for a valve actuator according to claim 8, characterized in that, It also includes an emergency unlocking unit. The emergency unlocking unit includes a manual knob and a mechanical unlocking link. The manual knob penetrates through the side wall of the outer shell (2) and is linked with a mechanical lock. The mechanical unlocking link is provided with a force-limiting spring assembly; When the mechanical lock is abnormally locked, rotate the manual knob to drive the mechanical unlocking link through the force-limiting spring assembly, thereby releasing the locked state of the mechanical lock.

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