Integrated speed and displacement measurement sensor for valve

Abstract

The invention discloses an integrated speed and displacement measurement sensor for a valve, and relates to the technical field of sensors for valves of servo valves. Comprising a sensor framework, a sensor shell, a linear Hall sensor, a circuit board, a coil sensor and an iron core, the sensor framework is located in the sensor shell, the linear Hall sensor is installed on a side window of the sensor framework, and the circuit board is installed at the plane end of the lower portion of the sensor framework. The coil sensor is wound in an annular groove in the upper part of the sensor framework; the iron core is connected with a process hole of a servo valve element through a connecting rod, the two linear Hall sensors are arranged on the two sides of the iron core in the same direction, and an outer protruding structure of a sensor shell is connected with the side face of a servo valve body through a sealing ring so that a sealing cavity can be formed in the valve body. The sensor provided by the invention integrates the functions of measuring speed and displacement, the miniaturization of the sensor is realized, the applicability of the sensor on a servo valve is improved, the system size is reduced, and the production cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of valve sensor technology for servo valves, and specifically to an integrated velocity-displacement measurement sensor for valves. Background Technology

[0002] Currently, there is a lack of integrated, miniaturized valve core position and speed monitoring sensors suitable for general use in servo valves. Similar technologies exist in some existing patents, such as patent CN105156737B, which proposes a method for constructing a servo valve control system using computer communication and external displacement and speed sensors. However, the entire system is relatively large, and the displacement and speed sensors cannot be installed on the servo valve to achieve real-time position and speed feedback; the level of integration needs improvement. Patent CN108679026A proposes a method for achieving high-precision control of servo valves using multiple different sensors, but this requires significant modifications to the servo valve structure to accommodate multiple sensors.

[0003] Currently, the mainstream sensor used in servo valve products is the LVDT (Low Voltage Detector), which can only detect the position of a single valve core. Furthermore, it requires the design of corresponding encoding and demodulation circuits to convert the AC signal into a DC signal in order to obtain the valve core's direction and position. The encoding and demodulation circuits are generally quite large, accounting for about one-third of the sensor's circuitry, which hinders the miniaturization and low-cost implementation of the sensor. Summary of the Invention

[0004] The main objective of this invention is to provide an integrated velocity-displacement measurement sensor for valves, in order to overcome the problems existing in the prior art.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] An integrated velocity-displacement measurement sensor for valves includes a sensor frame, a sensor housing, a linear Hall sensor, a circuit board, a coil sensor, and an iron core. The sensor frame is located inside the sensor housing. The linear Hall sensor is fixedly installed on the side window of the sensor frame. The circuit board is installed on the lower flat end of the sensor frame. The coil sensor is wound in the annular groove on the upper part of the sensor frame.

[0007] The iron core is fixedly connected to the process hole of the servo valve core via a connecting rod. The two linear Hall sensors are arranged in the same direction on both sides of the iron core. The upper part of the sensor housing is a convex structure. The convex structure is connected to the side of the servo valve body through a sealing ring, so that the interior of the valve body forms a sealed cavity.

[0008] Furthermore, it also includes an isolator disposed on the outside of the iron core.

[0009] Furthermore, the circuit board integrates an MCU processor, which is electrically connected to both the linear Hall sensor and the coil sensor.

[0010] Furthermore, an electrical communication interface is installed on the opening side of the sensor housing.

[0011] Furthermore, the electrical communication interface is an analog interface or a digital interface. The analog interface is a 4-20mA current output interface or a 0-10V voltage output interface, and the digital interface is an interface using differential output.

[0012] Furthermore, the outer side of the sensor frame is connected to the sensor housing using encapsulating adhesive.

[0013] Furthermore, the circuit board is soldered to the socket at the planar end of the sensor frame.

[0014] Furthermore, the isolator is made of steel.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1) Since servo valves have different process requirements and flow channel design requirements for valve body, valve sleeve, and valve core, servo valves generally require an end cap to be installed on the side to form a sealed cavity inside the valve body, and the valve core needs to be machined with process holes. However, the sensor of this invention utilizes an existing and necessary structure to connect the magnetized iron core of the sensor signal generation end to the process hole on the valve core through a connecting rod, and connects to the side of the servo valve body through the outward protrusion structure on the upper part of the sensor housing, thereby replacing the end cap. This allows for integrated installation of the sensor without modifying the servo valve structure, reducing the cost of interface improvements for multiple sensors and servo valve flow channel design.

[0017] 2) The linear Hall sensor, circuit board, coil sensor, sensor frame and sensor frame are integrated into a sensor component, realizing integration and miniaturization, and can realize the function of measuring valve core speed and displacement by a single sensor component.

[0018] 3) The circuit board and MCU processor can perform temperature compensation, filtering and linearization on the Hall voltage of the linear Hall sensor and the coil sensor, and output the signal through the electrical communication interface. The analog interface with 4-20mA current output or 0-10V voltage output and the digital interface with differential output can be selected as needed, and it is compatible with the mainstream electrical communication interfaces of current servo valves.

[0019] 4) By encapsulating the sensor frame and sensor housing with encapsulating glue and setting an isolator, the pressure resistance range of the sensor is improved, and the pressure applicability of the sensor in servo valves is broadened.

[0020] 5) Compared to traditional LVDT differential transformer displacement sensors used in proportional valves and servo valves, which require dedicated LVDT modem chips or very complex modem design circuits to process the AC signal output by the sensor into a DC voltage signal proportional to the displacement stroke, the sensor of this invention can output analog signals with a current output of 4-20mA or a voltage output of 0-10V adapted to servo valve control. This eliminates the need for matching modem chips (such as AD598, AD698 chips, etc., which are very expensive) or circuits on the servo valve main control circuit board, effectively reducing the design cost of valve controllers. It also optimizes the circuit board layout space, making the circuit board design more miniaturized and compact, while improving reliability. Attached Figure Description

[0021] Figure 1 This is a front sectional view of the present invention.

[0022] Figure 2 This is a side sectional view of the present invention.

[0023] Figure 3 This is a schematic diagram of the present invention.

[0024] Figure 4 This is a front view of the present invention.

[0025] Figure 5 This is a side view of the present invention.

[0026] Figure 6 This is a top view of the present invention.

[0027] Figure 7 This is a bottom view of the present invention.

[0028] Explanation of reference numerals in the attached diagram: 1-Sensor frame, 2-Sensor housing, 3-Linear Hall sensor, 4-Circuit board, 5-Coil sensor, 6-Iron core, 7-Isolator. Detailed Implementation

[0029] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0030] The main objective of this invention is to provide a universal solution for integrated and miniaturized valve sensors, enabling a single sensor to integrate the functions of measuring speed and displacement. Through structural design, the coil sensor, sensor frame, and circuit board are integrated into the sensor housing, thereby achieving sensor miniaturization, improving the applicability of the sensor in servo valves, reducing system size, and lowering production costs.

[0031] Combination Figures 1 to 7 This embodiment provides an integrated velocity-displacement measurement sensor for valves, including a sensor frame 1, a sensor housing 2, a linear Hall sensor 3, a circuit board 4, a coil sensor 5, an iron core 6, and an isolator 7.

[0032] The sensor frame 1, linear Hall sensor 3, circuit board 4, and coil sensor 5 are all located inside the sensor housing 2. The linear Hall sensor 3 is fixedly installed on the side window of the sensor frame 1, the circuit board 4 is installed on the lower flat end of the sensor frame 1, and the coil sensor 5 is wound in the annular groove on the upper part of the sensor frame 1, thereby realizing the integration and miniaturization of the sensor.

[0033] The iron core 6 is fixedly connected to the process hole of the servo valve core through a connecting rod. Two linear Hall sensors 3 are arranged in the same direction on both sides of the iron core 6. The upper part of the sensor housing 2 is a convex structure. The convex structure is connected to the side of the servo valve body through a sealing ring, so that the inside of the valve body forms a sealed cavity, thereby replacing the end cover and realizing the integrated installation of the sensor without modifying the servo valve structure.

[0034] As a preferred option, the isolator 7 is made of steel and is located on the outside of the iron core 6. It can isolate the oil pressure inside the isolator 7 without affecting the sensor measurement, thereby improving the pressure resistance of the sensor.

[0035] In this embodiment, an MCU processor is integrated on the circuit board 4. The MCU processor is electrically connected to the linear Hall sensor 3 and the coil sensor 5. The coil sensor 5 is a speed-sensing coil sensor.

[0036] In this embodiment, an electrical communication interface is installed on the opening side of the sensor housing 2. Preferably, the electrical communication interface is an analog interface or a digital interface. The analog interface is a 4-20mA current output interface or a 0-10V voltage output interface, and the digital interface is an interface using differential output.

[0037] In this embodiment, the outer side of the sensor frame 1 and the sensor housing 2 are bonded together with encapsulating adhesive. Figure 2 Encapsulation and connection are performed near the gray area.

[0038] In this embodiment, the circuit board 4 is soldered to the socket at the flat end of the sensor frame 1.

[0039] During installation, the circuit board and the opening surface of the sensor housing 2 are on the same side. The opening surface of the sensor housing 2 can be selected to install a pressure-resistant electrical communication interface as needed. After the electrical communication interface is installed, the inside of the sensor housing 2 and the outside of the sensor frame 1 are sealed with glue (near the gray area). This not only provides short-circuit shielding but also fixes the sensor frame 1, linear Hall sensor 3, circuit board 4, and coil sensor 5, ensuring the structural strength of the circuit and the sensor.

[0040] Sensor measurement principle:

[0041] An iron core 6, securely connected to the valve core via a connecting rod, extends into the encapsulated sensor. The iron core 6, after being charged and demagnetized, possesses a stable magnetic field strength and can move in the same axial direction as the valve core. The displacement of the iron core 6 causes a change in the vertical magnetic field strength experienced by the linear Hall sensor 3. When the iron core 6 moves upward, the vertical magnetic field strength decreases; when it moves downward, the vertical magnetic field strength increases. Simultaneously, the thickness, material, and current of the linear Hall sensor 3 are fixed, so the Hall voltage is only related to the vertical magnetic field strength. The valve core displacement is determined by measuring the Hall voltage (the valve core displacement is small, with a maximum stroke of less than 1 mm, preventing it from exceeding the measurement range). Two linear Hall sensors 3 are mounted in the same direction on both sides of the measuring iron core 6, compensating for small-angle tilts of the iron core 6. The circuit board 4 contains a temperature sensor and a temperature compensation circuit to enhance the Hall voltage and reduce errors.

[0042] Since a single sensor integrates a linear Hall sensor 3 and a coil sensor 5, the coil sensor 5 generates a corresponding induced electromotive force while the valve core is moving. By measuring the voltage change at the sensing point, the speed of the valve core movement can be measured.

[0043] The measured signal is filtered, linearized, and temperature-compensated by the MCU processor. Communication with the control terminal is achieved via electrical communication interfaces selected through openings on the two sides of the sensor housing. Analog interfaces with 4–20mA current output or 0–10V voltage output, as well as digital interfaces using differential output, can be selected as needed. This ensures compatibility with mainstream electrical interfaces for servo valves, meaning the servo valve's main control board can directly use the sensor signal. After the main control circuit adjusts the control signal, higher precision, stability, and faster valve core control are achieved.

[0044] In this embodiment, through structural and circuit design, a linear Hall sensor 3 and a coil sensor 5 are integrated on a single sensor assembly, enabling a single sensor to simultaneously measure the speed and displacement of the valve core.

[0045] Through the design of the sensor frame 1, the coil sensor 5 is wound inside the upper annular groove of the sensor frame. Two linear Hall sensors 3 are fixed to the lower half of the square window side of the sensor frame 1 through the mounting window, and are soldered to the circuit board 4 through the insertion hole on the sensor frame 1. The circuit board 4 is mounted on the flat end of the sensor frame 1. The main components are rationally distributed in space through the frame design, which realizes the miniaturization of the structure.

[0046] The sensor frame 1, sensor housing 2, and circuit board 4 are fixed by encapsulating adhesive, which improves the pressure resistance and sealing of these parts, enabling them to work in a wider range of oil pressures. At the same time, it is equipped with an isolator, which can isolate high-pressure oil inside the sensor without affecting the magnetic circuit, further improving the adaptability of oil pressure.

[0047] The sensor housing 2 is designed with an outward convex structure to encapsulate the sensor part inside. The outward convex structure of the sensor housing 2 is connected to the side of the valve body through a sealing ring, so that the inside of the valve body forms a sealed cavity, ensuring the integrity of the internal flow channel and replacing the function of the end cap. It is compatible with the structure of most servo valve hardware, and the housing with different radii can be replaced according to the interface requirements to achieve hardware interface adaptation.

[0048] The sensor's signal generation end utilizes a magnetic core 6, which is fixed to the servo valve core via a connecting rod and a process hole. When the valve core is displaced by the input signal, it causes the magnetic core 6 to move relative to it. The magnetic field changes at the generation end are then collected by a coil sensor 5 and a linear Hall sensor 3 at the acquisition end. After temperature compensation, the Hall voltages of the two linear Hall sensors 3 (one on each side, one in the same direction) are measured. The signal is then output from the electrical communication interface via the internal circuit board 4 and the MCU processor. The interface can be configured with either a 4-20mA current output or a 0-10V voltage output analog interface, or a differential output digital interface, compatible with current mainstream servo valve electrical interfaces. This means the servo valve's main control board can directly use the sensor's signal. After adjusting the control signal through the main control circuit, higher precision, stability, and faster valve core control are achieved. The hardware and electrical interface designs are compatible with current mainstream servo valve interfaces, enhancing the sensor's applicability in servo valves.

[0049] The sensor provided in this embodiment has been used in the 634 jet tube servo valve developed by the 704 Research Institute of China Shipbuilding Industry Corporation, and has achieved good results, especially in improving the valve core control accuracy and dynamic performance, and reducing manufacturing and maintenance costs.

[0050] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the technical scope of the present invention. Therefore, any minor modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. An integrated all-in-one velocity displacement measurement sensor for a valve, characterized by, The sensor assembly includes a sensor frame (1), a sensor housing (2), a linear Hall sensor (3), a circuit board (4), a coil sensor (5), and an iron core (6). The sensor frame (1) is located inside the sensor housing (2). The linear Hall sensor (3) is fixedly installed on the side window of the sensor frame (1). The circuit board (4) is installed on the lower flat end of the sensor frame (1). The coil sensor (5) is wound in the annular groove at the upper part of the sensor frame (1). The iron core (6) is fixedly connected to the process hole of the servo valve core through a connecting rod. The two linear Hall sensors (3) are arranged in the same direction on both sides of the iron core (6). The upper part of the sensor housing (2) is a convex structure. The convex structure is connected to the side of the servo valve body through a sealing ring so that the inside of the valve body forms a sealed cavity.

2. An integrated one-piece velocity displacement measurement sensor for a valve as defined in claim 1, wherein It also includes an isolator (7) disposed on the outside of the iron core (6).

3. An integrated one-piece velocity displacement measurement sensor for a valve as defined in claim 1, wherein, The circuit board (4) integrates an MCU processor, which is electrically connected to the linear Hall sensor (3) and the coil sensor (5) respectively.

4. An integrated one-piece velocity displacement measurement sensor for a valve as defined in claim 1, wherein, An electrical communication interface is installed on the opening side of the sensor housing (2).

5. An integrated one-piece velocity displacement measurement sensor for a valve as defined in claim 4, wherein, The electrical communication interface is either an analog interface or a digital interface. The analog interface is a 4-20mA current output interface or a 0-10V voltage output interface, and the digital interface is an interface using differential output.

6. The integrated velocity-displacement measurement sensor for valves as described in claim 1, characterized in that, The outer side of the sensor frame (1) is connected to the sensor housing (2) by encapsulating adhesive.

7. The integrated velocity-displacement measurement sensor for valves as described in claim 1, characterized in that, The circuit board (4) is soldered to the socket at the flat end of the sensor frame (1).

8. The integrated velocity-displacement measurement sensor for valves as described in claim 2, characterized in that, The isolator (7) is made of steel.

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