Limiting protection device of valve actuator

Abstract

The invention relates to the field of mechanical engineering, in particular to a limiting protection device of a valve actuator, which comprises the valve actuator for driving a valve to open and close, a mounting bracket and a limiting protection device main body, a driving piece is arranged in the valve actuator, and the limiting protection device main body comprises a shell and a limiting switch unit, the interior of the shell is divided into a sensor cabin, a control cabin and a brake cabin. A detection unit is installed on the output shaft, a control unit is installed in the control cabin, and the control unit is used for receiving angle and displacement data detected by the detection unit in real time and conducting redundancy check according to the angle and displacement data detected in real time. A self-locking unit is installed in the brake cabin, an early warning unit is installed on the outer side wall of the shell, and the early warning unit is used for conducting early warning according to the judgment result of the control unit. According to the limiting protection device, the defects of a traditional limiting protection device in the aspects of safety, adaptability, stability and operability are overcome, and the operation reliability and maintenance efficiency of the valve actuator are remarkably improved.

Description

Technical Field

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

[0002] In industrial automation systems, the limit protection device of the valve actuator is a core component to ensure accurate control and safe operation of the valve opening and closing action. Traditional limit protection devices mostly use a single mechanical limit or electronic sensor to achieve position detection, such as a mechanical stopper with a contact limit switch, or rely on a single signal source such as a Hall sensor. However, this type of design has many defects in practical applications: Insufficient safety: Mechanical limit switches rely on rigid contact triggering, and valve actuators are prone to impact loads when they stop suddenly at the limit position, causing wear or even breakage of transmission parts (such as gears and couplings). Single electronic sensors are prone to signal distortion in high temperature, vibration or electromagnetic interference environments, resulting in misjudgment or missed judgment, and there is a risk of overtravel.

[0003] 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 cause the valve to lose control. For example, after the encoder fails, the redundant sensor cannot continue to monitor the displacement, and the control system loses the basis for protection logic judgment.

[0004] Limited dynamic adjustment capability: Most devices use fixed threshold limits and cannot dynamically adjust the deceleration range according to load changes (such as pipeline pressure fluctuations, valve sticking), resulting in frequent triggering of hard limits or premature braking, reducing operating efficiency.

[0005] Although some improvement solutions have proposed dual sensors or buffer structures to address the above problems, they still do not systematically integrate functions such as multi-level limit protection 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 valve actuators in complex industrial environments. Summary of the invention

[0006] In order 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 supply redundancy, quick installation and emergency unlocking, the present invention 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.

[0007] In order to achieve the above-mentioned purpose, the technical scheme of the present invention is as follows: a limit protection device for a valve actuator, comprising a valve actuator for driving a valve to open and close, a mounting bracket and a limit protection device body, a driving member is arranged inside the valve actuator, the limit protection device body is mounted on one side of an output shaft of the driving member through the mounting bracket, the limit protection device body comprises: a housing and a limit switch unit, the interior of the housing is divided into a sensor cabin, a control cabin and a brake cabin; A detection unit is installed on the output shaft; A control unit is installed in the control cabin; The limit switch unit includes a first limit switch and a second limit switch; A self-locking unit is installed in the brake cabin, and the self-locking unit includes an electromagnetic brake and a mechanical lock. The electromagnetic brake is coaxially fixedly connected with the output shaft of the driving member, and the mechanical lock is linked with the mechanical limit switch; An early warning unit is installed on the outer wall of the housing, and the early warning unit is used to issue an early warning according to the judgment result of the control unit; 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; 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 simultaneously starts the electromagnetic brake and mechanical lock 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.

[0008] Furthermore, the detection unit includes an encoder and a magnetic grating sensor, the encoder is installed at one end of the output shaft of the driver, and the magnetic grating sensor is embedded in the side wall of the output shaft of the driver, and the encoder and the magnetic grating sensor are used to detect the rotation angle and linear displacement of the output shaft of the driver in real time; 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 redundancy check according to the angle and displacement data detected in real time; The first limit switch is an electronic limit switch, which is installed in the safety buffer area of ​​the output shaft, and the second limit switch is a mechanical limit switch, which is installed at the travel limit position of the output shaft; The early warning unit includes an indicator light and a buzzer. The indicator light is used to flash and emit light of different colors to indicate different early warning reminders. The buzzer is used to emit different alarm sounds. Both the indicator light and the buzzer are connected to the controller signal. When the controller determines that the real-time detected angle and location data are different from the preset limit value, the early warning unit emits an audible and visual alarm signal.

[0009] Furthermore, the dynamic threshold storage module has a built-in 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: ; in is the historical displacement standard deviation, is the ambient temperature compensation coefficient.

[0010] Furthermore, partitions are installed between each compartment inside the shell, and the partitions are electromagnetic shielding partitions.

[0011] Furthermore, an active heat dissipation component is provided in the sensor compartment of the outer shell, and the active heat dissipation component includes a fan and a temperature sensor. The fan and the temperature sensor are fixedly connected to the inner wall of the outer shell corresponding to the sensor compartment. A directional air duct is opened on the side wall of the outer shell corresponding to the sensor compartment. The fan and the temperature sensor are connected to the controller signal. The controller dynamically adjusts the heat dissipation intensity of the fan according to the temperature data monitored in real time by the temperature sensor.

[0012] Furthermore, an adjustable guide vane is provided in the directional air duct, and the guide vane is connected to a controller. The controller dynamically adjusts the angle of the guide vane according to data from a temperature sensor, thereby adjusting the heat dissipation airflow path.

[0013] Furthermore, a main power module and a backup power module are installed in the control cabin. Both the main power module and the backup power module use supercapacitors. The backup power module is connected in parallel with the main power supply. When the main power supply is cut off, the backup power module is automatically switched.

[0014] Furthermore, it also includes a remote communication module, the remote communication module signal is connected to the smart 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 early warning unit to the smart device in real time.

[0015] Furthermore, the mounting bracket is a U-shaped groove structure, the opening of the U-shaped groove faces the output shaft of the driving member, and the two side walls of the mounting bracket are provided with a plurality of evenly distributed mounting holes, and the mounting holes are used to fix the mounting bracket on the output shaft of the driving member through fasteners; A positioning groove and a guiding inclined surface are arranged at the bottom of the U-shaped groove of the mounting bracket, and a sliding block matching with the positioning groove is arranged on the side wall of the main shell of the position limiting protection device, and the sliding block is slidably matched with the positioning groove.

[0016] Furthermore, it also includes an emergency unlocking unit, which includes a manual knob and a mechanical unlocking connecting rod, the manual knob passes through the side wall of the housing and is linked with the mechanical lock, and the mechanical unlocking connecting rod is provided with a force-limiting spring assembly; When the mechanical lock is abnormally locked, the manual knob is rotated to drive the mechanical unlocking link through the force limiting spring assembly, thereby releasing the locking state of the mechanical lock.

[0017] The technical principle of the above scheme is as follows: through the multi-level limit protection mechanism (electronic limit deceleration + mechanical hard limit) and redundant detection technology (encoder + magnetic grid 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 the self-learning algorithm to adapt to different working conditions and environmental changes. The interior of the shell is divided into a sensor cabin, a control cabin and a brake cabin. Electromagnetic shielding partitions are used between the cabins to isolate interference. The sensor cabin is equipped with an active heat dissipation component (fan + temperature sensor + adjustable guide blade) to dynamically adjust the heat dissipation intensity according to the real-time temperature. The control cabin is equipped with a main power supply and a supercapacitor backup power supply, which automatically switches when the power is off to ensure the continuous operation of the system. The remote communication module realizes real-time data transmission to the smart device and supports remote monitoring and command issuance. The mounting bracket adopts a U-shaped groove structure, and the slider and the positioning groove are slid together to achieve quick installation. The emergency unlocking unit (manual knob + mechanical unlocking connecting rod + force limiting spring assembly) provides a manual unlocking function when the mechanical lock is abnormally locked to avoid overload damage.

[0018] The above scheme has the following beneficial effects: 1. Multi-level protection improves safety: Traditional limit protection devices usually rely only 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 buffer mechanism, which can easily lead to over-limit operation due to inertia or misoperation, thereby causing equipment damage or safety accidents.

[0019] This solution effectively avoids the risk of output shaft overrun through the "electronic deceleration-mechanical hard limit" collaborative mechanism, significantly improving equipment safety. This multi-level protection mechanism significantly reduces the risk of equipment overrun and improves system safety.

[0020] 2. Redundant detection and dynamic adaptation: Traditional detection units usually rely on only a single sensor. The detection accuracy is greatly affected by the environment, and the limit threshold cannot be adjusted dynamically, resulting in poor limit protection effect under complex working conditions (such as temperature changes and mechanical wear).

[0021] This solution adopts the redundant detection design of encoder and magnetic grating sensor, and improves the detection accuracy through dual sensor data verification. At the same time, the dynamic threshold storage module has a built-in self-learning algorithm, which analyzes the displacement fluctuation (standard deviation) of the valve actuator in N consecutive working cycles. ), combined with the ambient temperature compensation coefficient , dynamically correct the limit threshold. This design enables the system to adapt to different working conditions and environmental changes, extending the service life of the equipment.

[0022] 3. Intelligent heat dissipation and electromagnetic isolation: The traditional sensor cabin lacks effective heat dissipation design, and the sensor accuracy decreases in high temperature environment; at the same time, there is a lack of electromagnetic shielding measures between the functional units, and the signal transmission is easily interfered, affecting the stability of the system.

[0023] This solution sets up active heat dissipation components (fan + temperature sensor + adjustable guide blades) in the sensor cabin, dynamically adjusts the heat dissipation intensity and airflow 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 the compartments inside the shell to effectively isolate electromagnetic interference and ensure the stability of signal transmission and detection accuracy.

[0024] 4. High reliability and continuous operation: This solution is equipped with a main power module and a supercapacitor backup power module in the control cabin. When the main power 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 command issuance, reduces the cost of manual intervention, and improves the intelligence level of the system.

[0025] 5. Quick installation and universal adaptation: This solution adopts modular design and U-shaped mounting bracket. The two side walls of the bracket are equipped with evenly distributed mounting holes, which are suitable for a variety of valve actuators. The bottom of the U-shaped groove of the mounting bracket is equipped with a positioning groove and a guide slope. The slider of the main shell of the limit protection device slides with the positioning groove, which simplifies the alignment and installation process, improves the installation efficiency by more than 50%, and is suitable for rapid deployment on industrial sites.

[0026] 6. Emergency safety guarantee: Compared with the prior art where the mechanical lock cannot be manually unlocked when abnormally locked, this solution provides an emergency unlocking unit, which achieves safe unlocking through a manual knob and a force-limiting spring assembly, avoids overload damage, and ensures controllability under extreme faults.

[0027] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a front view of an embodiment of a limit protection device for a valve actuator of the present invention; Figure 2 It is an axonometric view of an embodiment of a limit protection device for a valve actuator of the present invention; Figure 3 An exploded schematic diagram of an embodiment of a limit protection device for a valve actuator of the present invention; Figure 4 It is a framework diagram of an embodiment of a limit protection device for a valve actuator of the present invention.

[0029] The figure marks in the drawings of the specification include: 1. driving member; 101. output shaft; 2. housing; 201. sensor cabin; 202. control cabin; 203. brake cabin; 3. mounting bracket; 301. positioning groove; 302. mounting hole; 4. partition. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are 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 therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0032] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] The following is further described in detail through specific implementation methods: Embodiment 1:

[0034] As attached Figures 1 to 4As shown: a limit protection device for a valve actuator, comprising a valve actuator for driving the valve to open and close, a mounting bracket 3 and a limit protection device body, wherein a driving member 1 is provided in the valve actuator, and in this embodiment, the driving member 1 is a driving motor, and the limit protection device body is installed on one side of the output shaft 101 of the driving member 1 through the mounting bracket 3. The limit protection device body comprises: a housing 2 and a limit switch unit, and the interior of the housing 2 is divided into a sensor cabin 201, a control cabin 202 and a brake cabin 203. The mounting bracket 3 is a U-shaped groove structure, and the opening of the U-shaped groove faces the output shaft 101 of the driving member 1. Both side walls of the mounting bracket 3 are provided with a number of evenly distributed mounting holes 302, and the mounting holes 302 are used to fix the mounting bracket 3 on the output shaft 101 of the driving member 1 through fasteners (hexagon socket screws are selected in this embodiment). A positioning groove 301 and a guide inclined surface are provided at the bottom of the U-shaped groove of the mounting bracket 3, and a slider (not shown in the figure) matching the positioning groove 301 is provided on the inner side wall of the housing 2, and the slider is slidably matched with the positioning groove 301.

[0035] A detection unit is installed on the output shaft 101, and the detection unit includes an encoder (in this embodiment, an incremental photoelectric encoder is selected, and a model example is Omron E6B2-CWZ6C) and a magnetic grating sensor (in this embodiment, a magnetic scale and a magnetic head sensor are selected, and a model example is Renishaw RGH22 series). The encoder is installed at one end of the output shaft 101 of the driver 1, and the magnetic grating sensor is embedded in the side wall of the output shaft 101 of the driver 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 driver 1 in real time.

[0036] A control unit is installed in the control cabin 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 check based on the angle and displacement data detected in real time. The dynamic threshold storage module has a built-in 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: ; in is the historical displacement standard deviation, is the ambient temperature compensation coefficient.

[0037] A main power module and a backup power module are installed in the control cabin 202. Both the main power module and the backup power module use supercapacitors (24V supercapacitors are selected in this embodiment). The backup power module is connected in parallel with the main power supply. When the main power supply is cut off, the backup power module is automatically switched.

[0038] The limit switch unit includes a first limit switch and a second limit switch. The first limit switch is an electronic limit switch, which is installed in the safety buffer area of ​​the output shaft 101. The second limit switch is a mechanical limit switch, which is installed at the travel limit position of the output shaft 101. In this embodiment, the first limit switch uses a Hall sensor (such as the selected model: Honeywell SS49E), which detects the magnetic field change of the magnetic grid sensor embedded in the side wall of the output shaft 101 and feeds back the position signal to the controller in real time. When the displacement of the output shaft 101 reaches 90% of the preset limit value, the Hall sensor triggers the electronic limit deceleration signal. The second limit switch uses a roller 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 the roller lever of the mechanical limit switch, triggering the mechanical hard limit signal, and at the same time, the mechanical lock locks the position of the output shaft 101.

[0039] A self-locking unit is installed in the brake cabin 203, and the self-locking unit includes an electromagnetic brake and a mechanical lock. The electromagnetic brake is coaxially fixedly connected to the output shaft 101 of the driving member 1, and the mechanical lock is linked to the mechanical limit switch.

[0040] An early warning unit is installed on the outer wall of the housing 2, and the early warning unit is used to issue 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 different colors of light to indicate different early warning reminders, and the buzzer is used to emit different alarm sounds.

[0041] 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 to perform electronic limit deceleration.

[0042] 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 simultaneously starts the electromagnetic brake and mechanical lock of the self-locking unit.

[0043] The early warning unit sends different early warning signals according to the comparison results of the real-time detection data of the detection unit and the preset limit value. The indicator light and buzzer are connected to the controller signal. When the controller determines that the real-time detection angle and location data are different from the preset limit value, the early warning unit sends out an audible and visual alarm signal.

[0044] The specific implementation process is as follows: (1) Installation process: Manually fix the mounting bracket 3 to the output shaft 101 of the driving member 1 with bolts, ensuring that the opening of the U-shaped groove faces the output shaft 101. Use a torque wrench to tighten the bolts according to the preset torque value (20 N·m is selected in this embodiment) to ensure that the mounting bracket 3 is stable. Align the slider of the limit protection device body with the positioning groove 301 of the mounting bracket 3, and slide along the guide slope to the installation position. Use fasteners (hexagon socket screws are selected in this embodiment) to fix the limit protection device body to the mounting bracket 3.

[0045] The encoder is mounted on one end of the output shaft 101 of the driver 1, and the encoder is ensured to be coaxial with the output shaft 101. The magnetic grating sensor is embedded in the side wall of the output shaft 101, and the positions of the magnetic grating sensor and the encoder are ensured to correspond to ensure detection accuracy.

[0046] Connect the main power module and the backup power module to the control unit to ensure a 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 voltage of the main power module and the backup power module are both 24V.

[0047] (2) Debugging process: Start the control unit to perform system initialization and self-test. Check whether the signal output of the encoder and magnetic grating sensor is normal, and ensure that the detection unit can collect the rotation angle and linear displacement data of the output shaft 101 in real time.

[0048] According to the working requirements of the valve actuator, set the initial limit threshold (in this embodiment, the rotation angle limit value is ±90° and the linear displacement limit value is ±50mm). Enter the initial limit threshold in the control unit .

[0049] The valve actuator is allowed to perform N consecutive working cycles (N=10 in this embodiment), and the dynamic threshold storage module records the displacement data of each working cycle. Calculate the historical displacement standard deviation : ; in, For the Displacement data of the working cycle, for The average displacement of each working cycle.

[0050] Unread compensation coefficient according to environment (In this embodiment, = 0.5), calculate the corrected limit threshold : ; For example, if =50mm, =2mm, then: mm; The corrected limit threshold Stored in the dynamic threshold storage module.

[0051] (3) Usage process: 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 by the detection unit in real time 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 smooth deceleration of the output shaft 101.

[0052] 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 synchronously starts the electromagnetic brake of the self-locking unit, which is coaxially fixedly connected to the output shaft 101 of the drive member 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 stops completely.

[0053] The early warning unit sends different early warning signals according to the comparison results of the real-time detection data of the detection unit and the preset limit value. That is, when the displacement data reaches 90% of the preset limit value, the indicator light flashes yellow and the buzzer emits an intermittent alarm sound. When the displacement data reaches 100% of the preset limit value, the indicator light flashes red and the buzzer emits a continuous alarm sound. The operator takes corresponding measures according to the early warning signal, such as checking the working status of the valve actuator or adjusting the operating parameters.

[0054] When the main power module loses power, the backup power module automatically switches to ensure that the limit protection device continues to work. The control unit records the power switching event and issues a power failure alarm through the early warning unit.

[0055] Embodiment 2:

[0056] The difference from Example 1 is that partitions 4 are installed between each compartment inside the shell 2, and the partitions 4 are electromagnetic shielding partitions 4, and the partitions 4 are made of metal material with high magnetic permeability (galvanized steel plates are used in this embodiment).

[0057] The specific implementation process is as follows: In this embodiment, the thickness of the partition 4 is 1.5 mm, which can effectively shield electromagnetic interference in the frequency range of 10 kHz to 1 GHz, and the surface is coated with a conductive coating to enhance the electromagnetic shielding effect. A conductive sealing strip is installed between the contact surface of the partition 4 and the shell 2 to ensure the continuity of the electromagnetic shielding.

[0058] When the valve actuator is working, the electromagnetic shielding partition 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.

[0059] Embodiment 3:

[0060] The difference from Example 2 is that an active heat dissipation component is provided in the sensor compartment 201 of the outer shell 2, and the active heat dissipation component includes a fan and a temperature sensor. The fan and the temperature sensor are fixedly connected to the inner wall of the outer shell 2 corresponding to the sensor compartment 201, and a directional air duct is opened on the side wall of the outer shell 2 corresponding to the sensor compartment 201. The fan and the temperature sensor are both connected to the controller signal, and the controller dynamically adjusts the heat dissipation intensity of the fan according to the temperature data monitored in real time by the temperature sensor.

[0061] An adjustable guide vane is provided in the directional air duct, and the guide vane is connected to the controller. The controller dynamically adjusts the angle of the guide vane according to the data of the temperature sensor, thereby adjusting the heat dissipation airflow path.

[0062] The specific implementation process is as follows: The temperature sensor monitors the temperature in the sensor compartment 201 in real time and feeds the data back to the controller. In this embodiment, the temperature sensor collects temperature data once a 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.

[0063] That is, when the temperature is below 30°C, the fan runs at low speed. When the temperature reaches 30°C to 40°C, the fan runs at medium speed. When the temperature is above 40°C, the fan runs at high speed. For example, if the temperature sensor detects that the temperature is 35°C, the controller adjusts the fan speed to medium speed.

[0064] At the same time, the controller dynamically adjusts the angle of the guide vane according to the data of the temperature sensor to adjust the heat dissipation airflow path. When the temperature distribution in the sensor cabin 201 is uneven, the controller adjusts the angle of the guide vane to allow more airflow to flow to the high temperature area. For example, if the temperature on the left side is higher, the controller adjusts the angle of the guide vane to 30° to allow more airflow to flow to the left side.

[0065] For example, assuming that the temperature on the left side of the sensor cabin 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 guide vane angle to 30° to allow more airflow 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.

[0066] The active heat dissipation component ensures that the temperature in the sensor cabin 201 is kept within a reasonable range to avoid the influence of high temperature on the detection unit (encoder and magnetic grating sensor). For example, the encoder and magnetic grating sensor work at a suitable temperature to improve the detection accuracy. The controller dynamically adjusts the heat dissipation intensity of the fan and the angle of the guide vane according to the data of the temperature sensor to ensure that the temperature distribution in the sensor cabin 201 is uniform. For example, the controller adjusts the heat dissipation intensity in real time to avoid the temperature in the sensor cabin 201 being too high or too low.

[0067] When the temperature sensor detects an abnormal temperature, the controller will sound an alarm through the early warning unit. If the temperature exceeds 50°C, the indicator light of the early warning unit will flash red and the buzzer will sound a continuous alarm.

[0068] Embodiment 4:

[0069] The difference from Example 3 is that it also includes a remote communication module (a 4G communication module is selected in this embodiment), and the remote communication module signal is connected to a smart device (such as a mobile phone, a computer, and a tablet, etc.). 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 early warning unit to the smart device in real time.

[0070] The specific implementation process is as follows: Start the controller and remote communication module, perform initialization and self-test, check whether the signal connection of the communication module is normal, and ensure that it can establish communication with the smart device. Open the monitoring software on the smart device to observe whether the data of the detection unit, the status information of the control unit, and the alarm signal of the early warning unit can be received. Send control instructions on the smart device to observe whether the controller can execute the instructions.

[0071] The remote communication module transmits the data of the detection unit, the status information of the control unit and the alarm signal of the early warning unit to the intelligent device in real time. The operator monitors the working status of the valve actuator in real time through the intelligent device. At the same time, the operator sends control instructions through the intelligent device to remotely control the working status of the valve actuator.

[0072] For example, the operator can monitor the working status of the valve actuator in real time through the mobile phone: when the displacement reaches 90% of the preset limit value, the mobile phone receives an alarm prompt, and the operator sends a deceleration command remotely. 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.

[0073] Embodiment 5:

[0074] The difference from Example 4 is that it also includes an emergency unlocking unit (not shown in the figure), which includes a manual knob and a mechanical unlocking link. The manual knob passes through the side wall of the shell 2 and is linked with the mechanical lock. The mechanical unlocking link is provided with a force limiting spring assembly. The mechanical unlocking link is fixed to the manual knob and the mechanical lock using a pin to ensure that the mechanical unlocking link can rotate freely.

[0075] When the mechanical lock is abnormally locked, the manual knob is rotated to drive the mechanical unlocking link through the force limiting spring assembly, thereby releasing the locking state of the mechanical lock.

[0076] 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 to drive the mechanical unlocking link through the force-limiting spring assembly to release the locked state of the mechanical lock.

[0077] That is, the operator rotates the manual knob 90° clockwise, and the force-limiting spring assembly begins to compress. The mechanical unlocking connecting rod drives the mechanical lock to unlock, and the output shaft 101 returns to a free state.

[0078] 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 10N·m, the force-limiting spring assembly is compressed, the operator feels resistance, and stops turning the manual knob.

[0079] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A limit protection device for a valve actuator, comprising a valve actuator for driving a valve to open and close, a mounting bracket (3) and a limit protection device body, wherein a driving member (1) is provided in the valve actuator, and the limit protection device body is mounted on one side of an output shaft (101) of the driving member (1) through the mounting bracket (3), characterized in that: The main body of the limit protection device comprises: a housing (2) and a limit switch unit, wherein the interior of the housing (2) is divided into a sensor cabin (201), a control cabin (202) and a brake cabin (203); A detection unit is mounted on the output shaft (101); A control unit is installed in the control cabin (202); The limit switch unit includes a first limit switch and a second limit switch; A self-locking unit is installed in the brake cabin (203), the self-locking unit comprising an electromagnetic brake and a mechanical lock, the electromagnetic brake is coaxially fixedly connected to the output shaft (101) of the driving member (1), and the mechanical lock is linked to the mechanical limit switch; An early warning unit is installed on the outer wall of the housing (2), and the early warning unit is used to issue an early warning according to the judgment result of 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 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 mechanical lock 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.

2. The limit protection device for the valve actuator according to claim 1, characterized in that: The detection unit comprises an encoder and a magnetic grating sensor, the encoder being mounted on one end of an output shaft (101) of the driving member (1), the magnetic grating sensor being embedded in a side wall of the output shaft (101) of the driving member (1), the encoder and the magnetic grating sensor being used to detect the rotation angle and linear displacement of the output shaft (101) of the driving member (1) in real time; 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 redundancy check according to the angle and displacement data detected in real time; The first limit switch is an electronic limit switch, which is installed in a safety buffer area of ​​the output shaft (101); the second limit switch is a mechanical limit switch, which is installed at a travel limit position of the output shaft (101); The early warning unit includes an indicator light and a buzzer. The indicator light is used to flash and emit light of different colors to indicate different early warning reminders. The buzzer is used to emit different alarm sounds. Both the indicator light and the buzzer are connected to the controller signal. When the controller determines that the real-time detected angle and location data are different from the preset limit value, the early warning unit emits an audible and visual alarm signal.

3. The limit protection device for the valve actuator according to claim 2, characterized in that: The dynamic threshold storage module has a built-in 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: ； in is the historical displacement standard deviation, is the ambient temperature compensation coefficient.

4. The limit protection device for the valve actuator according to claim 3, characterized in that: Partitions (4) are installed between each compartment inside the housing (2), and the partitions (4) are electromagnetic shielding partitions (4).

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

6. The limit protection device for the valve actuator according to claim 5, characterized in that: An adjustable guide vane is provided in the directional air duct, and the guide vane is connected to the controller. The controller dynamically adjusts the angle of the guide vane according to the data of the temperature sensor, thereby adjusting the heat dissipation airflow path.

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

8. The limit protection device for the valve actuator according to claim 7, characterized in that: It also includes a remote communication module, the remote communication module signal is connected to the smart 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 early warning unit to the smart device in real time.

9. The limit protection device for the valve actuator according to claim 8, characterized in that: The mounting bracket (3) is a U-shaped groove structure, the opening of the U-shaped groove faces the output shaft (101) of the driving member (1), and the two side walls of the mounting bracket (3) are provided with a plurality of evenly distributed mounting holes (302), and the mounting holes (302) are used to fix the mounting bracket (3) on the output shaft (101) of the driving member (1) by means of 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), and a sliding block matching the positioning groove (301) is provided on the side wall of the main housing (2) of the position limiting protection device, and the sliding block is slidably matched with the positioning groove (301).

10. The limit protection device for the valve actuator according to claim 9, characterized in that: It also includes an emergency unlocking unit, which includes a manual knob and a mechanical unlocking connecting rod, the manual knob passes through the side wall of the housing (2) and is linked to the mechanical lock, and the mechanical unlocking connecting rod is provided with a force-limiting spring assembly; When the mechanical lock is abnormally locked, the manual knob is rotated to drive the mechanical unlocking link through the force limiting spring assembly, thereby releasing the locking state of the mechanical lock.

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