Full-automatic detection device for pressure test performance of valve

Abstract

The invention relates to the technical field of valve detection, and discloses a valve pressure test performance full-automatic detection device which comprises a rack, a left chuck, a right chuck, a supply / control loop, a pressure test pump valve group, a sensing acquisition unit, a pressure difference diagnosis module and a controller, the sensing acquisition unit is used for acquiring clamping counterforce of the left chuck and the right chuck and calculating counterforce difference to form unbalance loading, and the controller performs closed-loop deviation correction on the left proportional valve and the right proportional valve based on the unbalance loading and performs dynamic compensation in a pressure boosting and / or pressure maintaining stage so as to restrain unbalance loading drift caused by compression deformation or load redistribution of the valve to be tested. The two ends of the differential pressure diagnosis module are communicated with the left chuck pressure test channel and the right chuck pressure test channel respectively and used for detecting differential pressure diagnosis signals. And the controller carries out abnormity tracing on the basis of the steady state / fluctuation characteristics of the test pressure and the pressure difference diagnosis signal, and distinguishes leakage of the cavity A, leakage of the cavity B and leakage of the valve clack, so that the consistency and reliability of pressure test detection are improved.

Description

Technical Field

[0001] This invention relates to the field of valve testing technology, and in particular to a fully automatic valve pressure testing device. Background Technology

[0002] As critical control components in pipeline systems, valves typically undergo shell strength testing, sealing testing (valve disc / seat seal), and top seal testing before leaving the factory. Existing valve pressure testing equipment generally uses clamps to hold and position the valve under test, and then introduces the hydraulic or pneumatic test medium into the valve cavity through clamps or connectors to complete pressure increase, pressure holding, and leakage determination. With the diversification of valve specifications and the increasing demand for automated production, pressure testing equipment is gradually developing towards features such as "gas-water compatibility, automatic pressure increase and holding, automatic leak detection, and data traceability."

[0003] However, most existing pressure testing devices employ clamping methods with both ends clamping or one end fixed while the other is pushed forward. The clamping actuators often only provide unilateral or synchronous drive, typically relying on cylinder stroke, system pressure, or empirical settings as the basis for clamping. Although the force exerted by the clamp on the valve body at a single contact interface is equal to the reaction force of the valve body on the clamp according to Newton's third law, the left and right ends are two independent contact pairs, and their clamping forces are not necessarily equal. This can easily lead to inconsistent clamping forces (off-center loading) during actual clamping and pressure testing. Causes of off-center loading include: flatness / parallelism errors of the valve body's two end faces, non-collinear force lines due to clamp installation and guiding errors, additional torque introduced by clamping posture offset, and differences in friction between the left and right actuators, sealing resistance, or hysteresis of valve control elements. Off-center loading makes the valve body's stress state and deformation unstable, thus affecting the contact state of the sealing pair, leading to fluctuations in the pressure holding curve, inconsistent judgment of boundary leakage components, and inconsistent results from repeated clamping. This is especially problematic in automated leak detection and batch testing scenarios, easily resulting in disputed components and increased retesting costs.

[0004] On the other hand, the pressure testing process typically involves pressure increase and pressure holding stages. The valve body undergoes elastic deformation under pressure, and changes in internal pressure can cause load path redistribution, leading to a shift in the seemingly stable force state during the clamping stage during pressure increase or holding. Existing devices often lack real-time monitoring and adaptive adjustment capabilities for changes in clamping force, making it difficult to maintain a stable clamping state throughout the entire pressure testing process, thus affecting test consistency.

[0005] Therefore, existing pressure testing devices cannot correct the left and right clamping forces during the entire clamping and pressure testing process, which affects the consistency of repeated testing. This problem is particularly prominent in scenarios involving automated leak detection and batch testing, and urgently needs to be solved. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by proposing a fully automatic valve pressure testing device.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a fully automatic valve pressure testing device, comprising a frame, a left clamping plate and a right clamping plate for holding the valve to be tested, a supply / control circuit for conveying the test pressure medium, a test pressure pump valve group, a sensing and acquisition unit, a differential pressure diagnosis module, and a controller.

[0008] The frame is fixedly mounted with a first hydraulic cylinder and a second hydraulic cylinder arranged horizontally and mirror-symmetrically. The first hydraulic cylinder and the second hydraulic cylinder are respectively equipped with a left proportional valve and a right proportional valve to realize independent adjustment of the first hydraulic cylinder and the second hydraulic cylinder. The left clamping plate is driven by the first hydraulic cylinder and the right clamping plate is driven by the second hydraulic cylinder.

[0009] The left and right clamps are each provided with a test pressure channel. The test pressure pump valve group selectively supplies water pressure test medium and / or air pressure test medium to the test pressure channel through the supply / control circuit, so that the test pressure medium is introduced into the A and B chambers of the valve to be tested through the left and right clamps.

[0010] The sensing and acquisition unit is set on the force transmission path of the left and right clamping plates to obtain the clamping reaction force F_L on the left clamping plate side and the clamping reaction force F_R on the right clamping plate side.

[0011] The two ends of the differential pressure diagnostic module are respectively connected to the test pressure channels of the left and right clamping plates to indirectly connect to chambers A and B;

[0012] The controller is configured to:

[0013] (1) Calculate the off-center load based on the clamping reaction force, the off-center load is the reaction force difference ΔF=|F_L-F_R|, and perform closed-loop correction by adjusting the left proportional valve and the right proportional valve so that the off-center load does not exceed the preset threshold.

[0014] (2) During the pressure test and / or pressure holding stages, continuously monitor the off-center load and dynamically compensate and adjust the left proportional valve and the right proportional valve to suppress the off-center load changes caused by pressure deformation or load redistribution of the valve under test during the pressure test.

[0015] Preferably, a spherical sub-assembly is provided between the telescopic end of the first hydraulic cylinder and the left clamping plate. The spherical sub-assembly includes a spherical seat and a ball-head rod. The ball-head rod and the spherical seat cooperate to form a swingable connection, so that the left clamping plate can adaptively conform to the end face of the valve to be tested during the clamping process.

[0016] The first hydraulic cylinder has a first guide groove at its telescopic end. The end of the spherical seat away from the ball head rod is slidably connected to the first guide groove. The sensing and acquisition unit is fixedly installed between the inner wall of the first guide groove and the spherical seat. A buffer is provided between the spherical seat and the left clamping plate. The buffer is preferably a rubber ring or an elastic ring to absorb minor clamping errors and impact loads.

[0017] Preferably, a guide plate is slidably installed inside the frame, the right clamping plate is fixedly connected to the guide plate, the extension end of the second hydraulic cylinder is provided with a second guide groove, the end of the guide plate away from the right clamping plate is slidably connected to the second guide groove, and the sensing and acquisition unit is fixedly installed between the inner wall of the second guide groove and the guide plate.

[0018] Preferably, the sensing and acquisition unit is a tension-compression type sensor. Because the system pressure of the first hydraulic cylinder and the second hydraulic cylinder is affected by sealing friction, guide resistance, valve control hysteresis and clamping error, it cannot accurately reflect the actual clamping reaction force at the end face of the left and right clamping plates. Therefore, it is preferable to use a tension-compression type force sensor to directly measure F_L and F_R along the force transmission path.

[0019] Preferably, the differential pressure diagnostic module includes a detection chamber, with diaphragms fixedly installed at both ends of the detection chamber. A sealed storage chamber is formed between the two diaphragms and filled with silicone oil. A connecting rod and two return springs are provided inside the storage chamber. The two ends of the connecting rod are fixedly connected to the diaphragms, and a limit plate is fixedly installed on the surface of the connecting rod. The two return springs abut against both sides of the limit plate. A non-contact displacement sensor is fixedly installed on the surface of the differential pressure diagnostic module to detect the displacement of the limit plate and output a differential pressure diagnostic signal.

[0020] Preferably, the differential pressure diagnostic module is further provided with a bypass channel, and an electromagnetic control valve is provided on the bypass channel to control the opening and closing or the degree of opening of the bypass channel.

[0021] Preferably, the non-contact displacement sensor is used to acquire the displacement X of the limiting plate relative to the center position. The controller determines the direction of the pressure difference based on the sign of the displacement and determines the trend of the pressure difference based on the magnitude of the displacement or its rate of change over time. The center position is the position of the limiting plate when the pressures in chamber A and chamber B are equal or under a preset reference state.

[0022] Preferably, the controller uses the establishment conditions and / or steady-state conditions of the differential pressure diagnostic signal as permission conditions for entering the pressure holding and leak detection process or the next process; the steady-state conditions include that the fluctuation amplitude of the differential pressure diagnostic signal within a preset time window does not exceed a preset threshold.

[0023] Preferably, the controller generates a feedforward compensation amount for off-center load correction based on the pressure difference change between chamber A and chamber B as reflected by the differential pressure diagnostic signal. The feedforward compensation amount is used to correct the control amount of the left proportional valve and the right proportional valve during the pressure test and / or pressure holding stages, so as to reduce off-center load drift caused by pressure deformation of the valve under test or load redistribution.

[0024] Preferably, the controller simultaneously acquires test pressure change information and differential pressure diagnostic signal change information during the pressure holding and leak detection process, and determines the source of the abnormality accordingly;

[0025] When the test pressure decreases and the differential pressure diagnostic signal remains stable or its fluctuation meets the steady-state condition, the source of the abnormality is determined to be leakage of the valve under test.

[0026] When the test pressure decreases and the differential pressure diagnostic signal fluctuates significantly, fails to establish or maintain a steady state, the abnormality is determined to be caused by the failure to establish the working condition or by factors in the test system, and at least one corrective action is triggered, such as venting, waiting for steady state, repressurizing, or reclamping.

[0027] The present invention has the following beneficial effects:

[0028] 1. The fully automatic valve pressure testing device proposed in this invention achieves independent pressure regulation by using a first and second hydraulic cylinder arranged in a mirror-symmetrical manner with left and right proportional valves respectively. At the same time, the sensing and acquisition unit directly acquires the left and right clamping reaction forces F_L and F_R. The controller uses the reaction force difference ΔF=|F_L-F_R| as the off-center load amount for closed-loop correction. Therefore, it can automatically balance the left and right clamping forces during the clamping stage and continuously dynamically compensate during the pressure increase / holding stage. This suppresses off-center load drift caused by clamping errors, friction differences, pressure deformation of the valve under test, or load redistribution, thereby improving the repeatability and consistency of pressure test leak detection and reducing the retest rate.

[0029] 2. The fully automatic valve pressure testing device proposed in this invention sets a spherical sub-component and a buffer between the first hydraulic cylinder and the left clamping plate, so that the clamp has an adaptive fitting capability during the clamping process. It can actively eliminate the additional torque and local point contact caused by the non-parallel end faces / non-collinear force lines, reduce the probability of uneven force on the sealing surface and off-center load, and meet the requirements of off-center load correction to improve the basic conditions.

[0030] 3. The fully automatic valve pressure test performance testing device proposed in this invention has a differential pressure diagnosis module with diaphragms at both ends of the detection chamber to form a sealed storage chamber filled with silicone oil. The diaphragms drive the displacement of the limit plate through the connecting rod, and a non-contact displacement sensor is set on the outside of the module to collect the displacement X of the limit plate relative to the center position. The controller determines the differential pressure direction according to the sign of the displacement and the differential pressure trend according to the magnitude of the displacement or the rate of change with time. Therefore, the differential pressure diagnosis signal does not depend on the test medium and directly enters the detection chamber. It can be applied to both water pressure test and air pressure test at the same time, avoiding the influence of water / air mixture, bubbles, and contamination on the diagnostic accuracy.

[0031] Since the differential pressure diagnostic module can output a stable signal reflecting the direction and trend of the differential pressure between chamber A and chamber B, the controller can use this signal as the working condition criterion and feedforward for off-center load correction: on the one hand, it can suppress or slow down the correction action when the differential pressure has not been established or fluctuates greatly, so as to avoid the correction error caused by the unstable test conditions; on the other hand, it can correct the control quantities of the left proportional valve and the right proportional valve in advance before the load redistribution of the valve under test is caused by the change in differential pressure, thereby reducing the drift of the clamping reaction force difference during the pressure increase / holding stage and improving the stability of the off-center load closed loop and the consistency of the test judgment.

[0032] 4. The fully automatic valve pressure testing device proposed in this invention has a bypass channel in the differential pressure diagnosis module, which is controlled by an electromagnetic control valve to open or close. The controller can use the establishment and steady state of the differential pressure diagnosis signal as a condition for entering the pressure holding and leak detection process. During the pressure holding process, the controller compares the steady-state / fluctuation characteristics of the test pressure change and the differential pressure diagnosis signal. When the pressure decreases and the differential pressure remains steady, it is determined that the valve under test is leaking. When the pressure decreases and the differential pressure fluctuates greatly or cannot remain steady, it is determined that the working condition has not been established or there are factors in the test system, and the device triggers venting, steady-state waiting, repressurization, or re-clamping. Thus, the differential pressure diagnosis module is used to "eliminate misjudgments caused by reasons other than the valve under test", thereby improving the anti-interference ability and reliability of the fully automatic pressure test. Attached Figure Description

[0033] Figure 1 This is a three-dimensional structural diagram of the fully automatic valve pressure testing device proposed in this invention. Figure 1 .

[0034] Figure 2 This is a three-dimensional structural diagram of the fully automatic valve pressure testing device proposed in this invention. Figure 2 .

[0035] Figure 3 This is a three-dimensional structural diagram of the left and right clamping discs proposed in this invention.

[0036] Figure 4 This is a three-dimensional structural diagram of the valve opening and closing actuator proposed in this invention.

[0037] Figure 5 This is a schematic diagram of the cross-sectional structure of the left and right clamping plates proposed in this invention.

[0038] Figure 6 This is a schematic diagram of the orthographic structure of the spherical seat and ball head rod proposed in this invention.

[0039] Figure 7 This is a perspective structural diagram of the left clamping plate, the valve to be tested, and the right clamping plate proposed in this invention.

[0040] Figure 8 This is a schematic diagram of the cross-sectional structure of the differential pressure diagnostic module proposed in this invention.

[0041] In the picture:

[0042] 100. Frame; 101. Guide plate; 102. Valve opening and closing actuator;

[0043] 201. Left clamping plate; 202. Right clamping plate; 203. First hydraulic cylinder; 204. Second hydraulic cylinder;

[0044] 301. Supply / control circuit; 302. Test pump valve assembly;

[0045] 400. Sensor acquisition unit;

[0046] 500. Differential pressure diagnostic module; 501. Diaphragm; 502. Connecting rod; 503. Return spring; 504. Limit plate; 505. Non-contact displacement sensor; 506. Bypass channel; 507. Solenoid control valve;

[0047] 601. Spherical seat; 602. Ball head; 603. Buffer component;

[0048] 700. Valve to be tested. Detailed Implementation

[0049] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0050] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0051] Example 1: Basic Structure of a Fully Automatic Valve Pressure Testing Performance Detector

[0052] Reference Figures 1-8 A fully automatic valve pressure testing device includes a frame 100, a left clamping plate 201 and a right clamping plate 202 for holding the valve 700 to be tested, a supply / control circuit 301 for conveying the test pressure medium, a test pressure pump valve group 302, a sensing and acquisition unit 400, a differential pressure diagnosis module 500, and a controller.

[0053] A first hydraulic cylinder 203 and a second hydraulic cylinder 204 are fixedly mounted on the frame 100 in a horizontal and mirror-symmetrical arrangement. The first hydraulic cylinder 203 and the second hydraulic cylinder 204 are respectively equipped with a left proportional valve and a right proportional valve to realize independent adjustment of the first hydraulic cylinder 203 and the second hydraulic cylinder 204. The left chuck 201 is driven by the first hydraulic cylinder 203, and the right chuck 202 is driven by the second hydraulic cylinder 204.

[0054] The left clamp 201 and the right clamp 202 are each equipped with a pressure test channel. The pressure test pump valve assembly 302 selectively supplies water pressure test medium and / or air pressure test medium to the pressure test channel through the supply / control circuit 301, so that the pressure test medium is introduced into the A chamber and B chamber of the valve under test 700 through the left clamp 201 and the right clamp 202 to complete the pressure increase, pressure holding and leakage determination. The pressure test pump valve assembly 302 is a conventional setting in the prior art and will not be described in detail here.

[0055] The sensing and acquisition unit 400 is used to acquire the clamping reaction force F_L on the left clamping plate 201 side and the clamping reaction force F_R on the right clamping plate 202 side respectively. It is preferably a tension-compression type force sensor, which is arranged on the force transmission path of the corresponding left clamping plate 201 and right clamping plate 202 to directly detect the clamping reaction force.

[0056] The two ends of the differential pressure diagnostic module 500 are connected to the test pressure channels of the left clamp 201 and the right clamp 202, respectively, so as to indirectly connect to the A and B chambers of the valve under test 700, and to obtain the diagnostic signal related to the differential pressure between the A and B chambers.

[0057] The controller is configured as follows:

[0058] (1) The off-center load is calculated based on the clamping reaction force. The off-center load is the reaction force difference ΔF=|F_L-F_R|. The off-center load is corrected by adjusting the left proportional valve and the right proportional valve in a closed loop so that the off-center load does not exceed the preset threshold.

[0059] (2) During the pressure test and / or pressure holding stages, continuously monitor the off-center load and dynamically compensate and adjust the left and right proportional valves to suppress the off-center load changes caused by the pressure deformation or load redistribution of the valve 700 under test during the pressure test.

[0060] In this embodiment, the test pressure channels of the left clamp 201 and the right clamp 202 are connected to the supply / control circuit 301 via quick-connect couplings, threaded couplings, or compression fittings. The outlet openings are located on one side of the valve under test 700, allowing the test pressure medium to enter the corresponding chamber of the valve under test 700 from the end faces of the left clamp 201 and the right clamp 202. The end faces of the left clamp 201 and the right clamp 202 are provided with multiple concentrically arranged sealing ring grooves, and sealing rings are installed in the sealing ring grooves. Under the action of clamping reaction force, they are pressed against the end face of the valve under test 700 to form an end face seal. A suitable sealing ring groove is selected to install the sealing ring to adapt to the end face structure or interface form of valves of different specifications.

[0061] Working principle / process:

[0062] Rapid approach phase: Control the first hydraulic cylinder 203 and the second hydraulic cylinder 204 to push the left clamp 201 and the right clamp 202 toward the valve to be tested 700;

[0063] Contact determination: When the sensing unit 400 detects that the clamping reaction force reaches the contact threshold and / or the reaction force rise rate exceeds the preset value, it determines that the left clamping plate 201 and the right clamping plate 202 are in contact with the end face of the valve under test 700 and enters the closed-loop correction stage.

[0064] Closed-loop correction: Real-time sampling of F_L and F_R calculates ΔF, and differential control is used to correct the outputs of the left and right proportional valves: when F_L>F_R, the output of the left proportional valve is reduced and / or the output of the right proportional valve is increased; when F_R>F_L, the output of the right proportional valve is reduced and / or the output of the left proportional valve is increased, so that ΔF converges to within the threshold. To avoid oscillation, a correction dead zone, a correction step size upper limit, and a regulation rate upper limit can be set.

[0065] Maintain compensation: ΔF is continuously monitored during the pressure boosting and holding stages. When ΔF exceeds the threshold window, a small correction is performed to suppress the clamping reaction force difference drift caused by the pressure deformation and load redistribution of the valve under test 700.

[0066] Example 2: Installation method of left clamping plate 201, right clamping plate 202 and sensing acquisition unit 400

[0067] like Figure 5 , Figure 6 As shown, a spherical sub-assembly is provided between the telescopic end of the first hydraulic cylinder 203 and the left clamping plate 201. The spherical sub-assembly includes a spherical seat 601 and a ball head rod 602. The ball head rod 602 and the spherical seat 601 cooperate to form a swingable connection, so that the left clamping plate 201 can adaptively fit the end face of the valve 700 under test during the clamping process, thereby reducing the non-parallelism of the end faces and the non-collinearity of the force lines and the local point contact caused by the clamping posture deviation.

[0068] Furthermore, a first guide groove is provided at the telescopic end of the first hydraulic cylinder 203, and the end of the spherical seat 601 away from the ball head rod 602 is slidably connected to the first guide groove to limit radial offset and allow axial sliding; the sensing and acquisition unit 400 is fixedly installed between the inner wall of the first guide groove and the spherical seat 601 so as to obtain the clamping reaction force while maintaining the spherical pair's swinging ability.

[0069] Furthermore, a buffer 603 is provided between the spherical seat 601 and the left clamping plate 201. The buffer 603 is preferably a rubber ring or an elastic ring to absorb minor clamping errors and impact loads, thereby improving the closed-loop convergence stability of ΔF.

[0070] like Figure 2 , Figure 3 , Figure 5 As shown, a guide plate 101 is slidably installed inside the frame 100, and the right clamping plate 202 is fixedly connected to the guide plate 101. The extension end of the second hydraulic cylinder 204 has a second guide groove. The end of the guide plate 101 away from the right clamping plate 202 is slidably connected to the second guide groove, so that the right clamping plate 202 moves stably in a straight line along the clamping direction and restricts the sway. The sensing and acquisition unit 400 is fixedly installed between the inner wall of the second guide groove and the guide plate 101 to obtain the right clamping reaction force F_R, so as to cooperate with the left clamping reaction force F_L to complete the off-center load closed-loop correction and dynamic compensation.

[0071] Example 3: Specific structure of differential pressure diagnostic module 500

[0072] like Figure 8 As shown, the differential pressure diagnostic module 500 is provided with a detection chamber. A diaphragm 501 is fixedly installed in both ports of the detection chamber. A sealed storage chamber is formed between the two diaphragms 501 and the storage chamber is filled with silicone oil medium.

[0073] A connecting rod 502 and two return springs 503 are installed inside the storage cavity. Both ends of the connecting rod 502 are fixedly connected to the diaphragm 501. A limiting disk 504 is fixedly mounted on the surface of the connecting rod 502, and the two return springs 503 abut against both sides of the limiting disk 504. A non-contact displacement sensor 505 is fixedly mounted on the surface of the differential pressure diagnostic module 500 to detect the displacement of the limiting disk 504 and output a differential pressure diagnostic signal.

[0074] Through the isolation of the diaphragm 501 and the transmission of silicone oil, the pressure difference between chamber A and chamber B causes the diaphragm 501 to generate a micro-displacement, which is transmitted to the limiting plate 504, realizing the "pressure difference → displacement" output mode. This can avoid the test medium from directly entering the test chamber and causing pollution, bubble interference, or the influence of medium difference, thus making it suitable for both water pressure test and air pressure test conditions.

[0075] like Figure 8As shown, the differential pressure diagnostic module 500 is also equipped with a bypass channel 506, and an electromagnetic control valve 507 is provided on the bypass channel 506 to control the opening and closing or the degree of opening of the bypass channel 506.

[0076] In this embodiment, the controller can control the solenoid control valve 507 as follows according to the pressure test requirements:

[0077] (1) Initialization / Benchmark Calibration Procedure: Before the start of the test or before each test procedure switch, the controller opens the solenoid control valve 507 to open the bypass channel 506, thereby balancing the pressure at both ends of the differential pressure diagnosis module 500, and the limit plate 504 returns to the neutral position. The controller reads the output of the non-contact displacement sensor 505 as the neutral zero point. After calibration, the bypass channel 506 is closed to enter the differential pressure establishment and diagnosis procedure.

[0078] (2) Pressure boosting and switching buffering process: In the initial stage of pressure boosting, valve group switching or when the pressure fluctuation is large, the controller can adjust the electromagnetic control valve 507 to a small opening, so that the bypass channel 506 provides throttling damping for the pressure difference change at both ends, suppresses the transient impact displacement of the diaphragm 501 and the limit plate 504, reduces the overshoot and jitter of the differential pressure diagnostic signal, and improves the stability of the differential pressure diagnostic signal.

[0079] (3) Universality of air pressure / water pressure conditions: When conducting air pressure tests, since gas is compressible and more susceptible to residual gas and fluctuations, the throttling damping of the bypass channel 506 helps to shorten the time for the differential pressure diagnostic signal to reach a steady state and improve readability; when conducting water pressure tests, since water medium has low compressibility and transient impacts are more obvious, the opening or throttling of the bypass channel 506 can achieve differential pressure impact peak reduction and buffer protection, so that the differential pressure diagnostic module 500 can stably output differential pressure direction and trend signals under both air pressure and water pressure test conditions, avoiding misjudgment caused by unstable operating conditions.

[0080] Example 4: Differential Pressure Diagnostic Module 500's Differential Pressure Direction / Trend Determination, Median Calibration, and Steady-State Permission

[0081] The non-contact displacement sensor 505 is used to acquire the displacement X of the limiting plate 504 relative to the center position. The controller determines the direction of the pressure difference based on the sign of the displacement and determines the trend of the pressure difference based on the magnitude of the displacement or its rate of change over time. The center position is the position of the limiting plate 504 when the pressures in chambers A and B are equal or under a preset reference state. Figure 8 As shown, with the bypass channel 506 closed by the electromagnetic control valve 507, the pressure in chamber A of the valve under test 700 is P_a, and the pressure in chamber B is P_b. When P_a < P_b, the limit plate 504 moves towards chamber A with a displacement of X = -L; when P_a > P_b, the limit plate 504 moves towards chamber B with a displacement of X = L; when P_a = P_b, the displacement X = 0.

[0082] (1) Initialization / calibration of median reference

[0083] In this embodiment, the controller initializes the differential pressure diagnostic module 500 before device startup or each test: it controls the solenoid valve 507 to open the bypass channel 506 to make the pressure at both ends more consistent, or reads the displacement sensor output as the midpoint zero point when chambers A and B are under equal pressure, and uses this zero point for subsequent calculation of the sign and amplitude of the displacement X. During the initial pressurization phase or after valve group switching, the controller can also briefly open the bypass channel 506 to suppress fluctuations, and close the bypass channel 506 to enter the leak detection process after the differential pressure diagnostic signal meets the establishment and steady-state conditions.

[0084] (2) Steady-state permitting conditions

[0085] The controller uses the establishment conditions and / or steady-state conditions of the differential pressure diagnostic signal as permission conditions for entering the pressure holding and leak detection process or the next process; the steady-state conditions include that the fluctuation amplitude of the differential pressure diagnostic signal within the preset time window does not exceed the preset threshold, so as to avoid false judgments caused by entering the leak detection process before the working conditions are established.

[0086] Example 5: Differential pressure in the differential pressure diagnostic module 500 participates in off-center load correction feedforward and anomaly cause correction.

[0087] The controller generates a feedforward compensation amount for off-center load correction based on the pressure difference change between chamber A and chamber B (e.g., the displacement X of limit plate 504 relative to the center position and / or its rate of change over time) in response to the pressure difference diagnostic signal. The feedforward compensation amount is used to correct the control quantities of the left and right proportional valves during the pressure test and / or pressure holding stages, so as to reduce the off-center load drift caused by the pressure deformation or load redistribution of the valve under test 700 and improve the convergence and stability of the off-center load closed loop.

[0088] In this embodiment, the controller converts the displacement X and / or displacement change rate into a feedforward compensation amount, and differentially superimposes it onto the control amounts of the left and right proportional valves. Under the premise that the differential pressure diagnostic signal has been established, the controller applies a pre-correction of equal magnitude and opposite direction to the left and right proportional valves, so that the redistribution of the clamping reaction force occurs in advance, thereby reducing the off-center load drift amplitude before the load change of the valve under test 700 causes a significant reaction force difference ΔF drift. The feedforward compensation amount can be set with amplitude and rate of change limits to avoid overcompensation caused by unsteady differential pressure or transient impact.

[0089] Furthermore, during the pressure holding and leak detection process, the controller simultaneously acquires information on changes in test pressure and changes in differential pressure diagnostic signals, and uses this information to determine the source of the anomaly.

[0090] When the test pressure decreases and the differential pressure diagnostic signal is established and shows a continuous and smooth trend (including monotonic changes or slow stabilization), and its high-frequency fluctuation amplitude within the preset time window does not exceed the preset threshold, the abnormality is more likely to originate from the leakage of the valve under test 700.

[0091] When the test pressure decreases and the differential pressure diagnostic signal cannot be established, or when there is obvious overshoot, repeated jumps or large fluctuations within the preset time window and the steady-state condition is not met, the abnormality is more likely to be caused by the failure to establish the working condition or by factors of the test system. This triggers at least one corrective action among venting, steady-state waiting, repressurization or reclamping, thereby reducing the probability of misjudging system factors as leakage of the valve under test 700 and improving the consistency of batch testing.

[0092] When the exhaust or steady-state waiting process is triggered, the controller can simultaneously control the bypass channel 506 to open or throttle to a small degree to accelerate the differential pressure diagnostic signal to enter steady state and shorten the correction time.

[0093] In this embodiment, to further distinguish between leakage in cavity A, leakage in cavity B, and internal leakage of the valve disc (cavity A and cavity B are connected), the controller uses the sign and time-varying trend of the displacement X output by the differential pressure diagnostic module 500, and combines it with the test pressure pump valve group 302 to determine the connection / isolation status of cavity A and cavity B. Specifically, during the pressure holding stage or diagnostic stage, the controller can isolate cavity A and cavity B through the supply / control loop 301 (e.g., closing the branch connected to cavity A and closing the branch connected to cavity B), and collect the displacement X and its changing trend within a preset time window:

[0094] (1) Judgment of leakage in cavity A: When the sign of displacement X indicates that the pressure P_a in cavity A is lower than the pressure P_b in cavity B (i.e., P_a < P_b, X is negative), and |X| shows a continuous increasing trend or gradually stabilizes under small fluctuations during the pressure holding process, while the test pressure decreases, it is more likely that the pressure difference is gradually established due to leakage from cavity A or leakage through the external passage on the side of cavity A.

[0095] (2) Judgment of leakage in cavity B: When the sign of displacement X indicates that the pressure P_b in cavity B is lower than the pressure P_a in cavity A (i.e., P_a > P_b, X is positive), and |X| shows a continuous increasing trend or gradually stabilizes under small fluctuations during the pressure holding process, while the test pressure decreases, it is more likely that the pressure difference is gradually established due to leakage from cavity B or leakage through the external passage on the side of cavity B.

[0096] (3) Valve disc internal leakage judgment: When the initial pressure difference (|X|>0) is diagnosed or the initial pressure difference is established by the manual operation of the test pressure pump valve group 302, and |X| shows a trend of gradually decreasing and approaching zero during the pressure holding process (that is, the pressure difference between cavity A and cavity B gradually disappears and the pressure of the two cavities tends to be balanced), and the test pressure decreases at the same time, it is more likely that there is internal leakage between cavity A and cavity B caused by the valve disc not closing tightly.

[0097] The controller can perform differential pressure initialization before the above discrimination: by opening the bypass channel 506 to make chamber A and chamber B equal pressure and establish a mid-level reference, and then closing the bypass channel 506 to enter the diagnosis; or by using the test pressure pump valve group 302 to perform alternating pressurization / isolation of chamber A and chamber B to establish an identifiable initial differential pressure, thereby improving the distinction between internal leakage and external leakage.

[0098] Example 6: Valve opening and closing actuator 102

[0099] like Figure 1 , Figure 2 , Figure 4 As shown, the frame 100 can also be optionally equipped with a valve opening and closing actuator 102, which is used to connect with the handwheel or valve stem of the valve under test 700 to realize the automatic opening and closing or preset opening degree of the valve under test 700, thereby improving the fully automatic detection adaptation capability. The valve opening and closing actuator 102 can also be used for valve disc internal leakage detection and repeated verification of sealing performance. For example, when the displacement X of the valve under test 700 is closed to the correct position each time, the displacement X shows that |X| gradually decreases and approaches zero within a preset time window, and the test pressure decays and shows a similar trend in repeated cycles, it can further corroborate the internal leakage caused by the valve disc not closing tightly, which is due to the interconnection between chamber A and chamber B. When the pressure difference trend changes significantly after repeated opening and closing or can be restored to a stable state, it can be used to eliminate occasional operating conditions or verify the repeatability and reliability of the valve disc sealing state. It should be noted that the valve opening and closing actuator 102 is an optional module and can be configured or omitted according to the valve type and production line cycle requirements. It is not a limitation of the essential components of this invention.

[0100] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A fully automatic valve pressure testing device, comprising a frame (100), a left clamping plate (201) and a right clamping plate (202) for holding the valve (700) to be tested, a supply / control circuit (301) for conveying the test pressure medium, a test pressure pump valve assembly (302), a sensing and acquisition unit (400), a differential pressure diagnostic module (500), and a controller, characterized in that: A first hydraulic cylinder (203) and a second hydraulic cylinder (204) are fixedly installed on the frame (100) in a horizontal and mirror-symmetrical arrangement. The first hydraulic cylinder (203) and the second hydraulic cylinder (204) are respectively provided with a left proportional valve and a right proportional valve to realize independent adjustment of the first hydraulic cylinder (203) and the second hydraulic cylinder (204). The left chuck (201) is driven by the first hydraulic cylinder (203), and the right chuck (202) is driven by the second hydraulic cylinder (204). The left clamp (201) and the right clamp (202) are each provided with a pressure test channel. The pressure test pump valve group (302) selectively delivers water pressure test medium and / or air pressure test medium to the pressure test channel through the supply / control circuit (301), so that the pressure test medium is introduced into the A and B chambers of the valve to be tested (700) through the left clamp (201) and the right clamp (202). The sensing and acquisition unit (400) is set on the force transmission path of the left clamping plate (201) and the right clamping plate (202) to acquire the clamping reaction force F_L on the left clamping plate (201) side and the clamping reaction force F_R on the right clamping plate (202) side; The two ends of the differential pressure diagnostic module (500) are respectively connected to the test pressure channels of the left clamp (201) and the right clamp (202) to indirectly connect to the A chamber and the B chamber; The controller is configured to: (1) Calculate the off-center load based on the clamping reaction force, the off-center load is the reaction force difference ΔF=|F_L-F_R|, and perform closed-loop correction by adjusting the left proportional valve and the right proportional valve so that the off-center load does not exceed the preset threshold. (2) During the pressure test and / or pressure holding stages, continuously monitor the off-center load and dynamically compensate and adjust the left proportional valve and the right proportional valve to suppress the off-center load change caused by the pressure deformation or load redistribution of the valve under test (700) during the pressure test.

2. The fully automatic valve pressure testing device according to claim 1, characterized in that: A spherical sub-assembly is provided between the telescopic end of the first hydraulic cylinder (203) and the left clamping plate (201). The spherical sub-assembly includes a spherical seat (601) and a ball head rod (602). The ball head rod (602) and the spherical seat (601) cooperate to form a swingable connection, so that the left clamping plate (201) can adaptively fit the end face of the valve (700) to be tested during the clamping process. The first hydraulic cylinder (203) has a first guide groove at its telescopic end. The end of the spherical seat (601) away from the ball head rod (602) is slidably connected to the first guide groove. The sensing and acquisition unit (400) is fixedly installed between the inner wall of the first guide groove and the spherical seat (601). A buffer (603) is provided between the spherical seat (601) and the left clamping plate (201). The buffer (603) is preferably a rubber ring or an elastic ring to absorb small clamping errors and impact loads.

3. The fully automatic valve pressure testing device according to claim 1, characterized in that: A guide plate (101) is slidably installed inside the frame (100). The right clamp (202) is fixedly connected to the guide plate (101). The telescopic end of the second hydraulic cylinder (204) is provided with a second guide groove. The end of the guide plate (101) away from the right clamp (202) is slidably connected to the second guide groove. The sensing and acquisition unit (400) is fixedly installed between the inner wall of the second guide groove and the guide plate (101).

4. The fully automatic valve pressure testing device according to claim 1, characterized in that: The sensing and acquisition unit (400) is a tension-compression type sensor.

5. The fully automatic valve pressure testing device according to claim 1, characterized in that: The differential pressure diagnostic module (500) is provided with a detection chamber. A diaphragm (501) is fixedly installed in both ends of the detection chamber. A sealed storage chamber is formed between the two diaphragms (501) and filled with silicone oil medium. A connecting rod (502) and two return springs (503) are provided in the storage chamber. The two ends of the connecting rod (502) are fixedly connected to the diaphragm (501) respectively. A limit plate (504) is fixedly installed on the surface of the connecting rod (502). The two return springs (503) are respectively pressed against the two sides of the limit plate (504). A non-contact displacement sensor (505) is fixedly installed on the surface of the differential pressure diagnostic module (500) for detecting the displacement of the limit plate (504) and outputting a differential pressure diagnostic signal.

6. The fully automatic valve pressure testing device according to claim 5, characterized in that: The differential pressure diagnostic module (500) is also equipped with a bypass channel (506), and an electromagnetic control valve (507) is provided on the bypass channel (506) to control the opening and closing or the degree of opening of the bypass channel (506).

7. The fully automatic valve pressure testing performance testing device according to claim 6, characterized in that: The non-contact displacement sensor (505) is used to obtain the displacement X of the limiting plate (504) relative to the center position. The controller determines the direction of the pressure difference according to the sign of the displacement and determines the trend of the pressure difference according to the magnitude of the displacement or its rate of change over time. The center position is the position of the limiting plate (504) when the pressures of chamber A and chamber B are equal or under a preset reference state.

8. A fully automatic valve pressure testing device according to any one of claims 1-7, characterized in that: The controller uses the establishment conditions and / or steady-state conditions of the differential pressure diagnostic signal as permission conditions for entering the pressure holding and leak detection process or the next process; the steady-state conditions include that the fluctuation amplitude of the differential pressure diagnostic signal within a preset time window does not exceed a preset threshold.

9. A fully automatic valve pressure testing device according to any one of claims 1-7, characterized in that: The controller generates a feedforward compensation amount for off-center load correction based on the pressure difference change between chamber A and chamber B as reflected by the differential pressure diagnostic signal. The feedforward compensation amount is used to correct the control amount of the left proportional valve and the right proportional valve during the pressure test and / or pressure holding stages, so as to reduce off-center load drift caused by pressure deformation or load redistribution of the valve under test (700).

10. A fully automatic valve pressure testing device according to any one of claims 1-7, characterized in that: During the pressure holding and leak detection process, the controller simultaneously acquires test pressure change information and differential pressure diagnostic signal change information, and determines the source of the abnormality accordingly. When the test pressure decreases and the differential pressure diagnostic signal remains stable or its fluctuation meets the steady-state condition, the source of the abnormality is determined to be leakage of the valve under test (700); When the test pressure decreases and the differential pressure diagnostic signal fluctuates significantly, fails to establish or maintain a steady state, the abnormality is determined to be caused by the failure to establish the working condition or by factors in the test system, and at least one corrective action is triggered, such as venting, waiting for steady state, repressurizing, or reclamping.

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