Full-automatic concrete impermeability instrument

Abstract

The invention provides a full-automatic concrete impermeability instrument. The full-automatic concrete impermeability instrument comprises a plurality of sealing testing devices, a multi-stage hydraulic cylinder, a water seepage detection array, a multi-stage pressurizing device and a closed-loop pressure controller, the multiple sealing testing devices are coaxially connected to piston rods of the multi-stage hydraulic cylinder respectively, each sealing testing device is provided with a multi-channel independent sealing cavity, the water seepage detection array is annularly distributed on the plane of the lowest end of each sealing cavity, and the water seepage detection array is composed of a humidity sensor and an image acquisition module. The multi-stage pressurizing device is arranged at the bottom of the instrument and comprises a high-precision hydraulic pump, a partial pressure valve group and an air pressure compensation unit, the closed-loop pressure controller controls the multi-stage hydraulic cylinder to drive the sealing test device to move up and down, and the output pressure gradient of the multi-stage pressurizing device is dynamically adjusted according to feedback data of the water seepage detection array. Parallel testing of multiple concrete test pieces is achieved, the pressure gradient is controllable, and the water seepage recognition precision and the testing accuracy are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete testing equipment, and more specifically, to a fully automatic concrete impermeability tester. Background Art

[0002] The impermeability performance of concrete is a key indicator for evaluating its durability, directly affecting the service life of the structure in water seepage, freeze-thaw and corrosion environments. Traditional impermeability testers mostly adopt the manual pressure application method for single specimens, which have problems such as low test efficiency, poor pressure control accuracy, and strong subjectivity in leakage judgment. Although existing automated equipment realizes pressure application through a hydraulic system, it generally has the following defects: (1) When multiple specimens are tested in parallel, the pressure gradients of each channel cannot be independently controlled, resulting in poor data comparability; (2) Relying on a single humidity sensor to detect water seepage is vulnerable to environmental interference and cannot capture the process of crack propagation; (3) Hydraulic pulsation and gas-liquid pressure imbalance cause fluctuations in the pressure curve, affecting the test accuracy. Summary of the Invention

[0003] In order to solve the above deficiencies of the prior art, the purpose of the present invention is to provide a fully automatic concrete impermeability tester to overcome the defects in the prior art.

[0004] To achieve the above object, the present invention provides a fully automatic concrete impermeability tester, which includes a plurality of sealing test devices, a multi-stage hydraulic cylinder, a water seepage detection array, a multi-stage pressurizing device and a closed-loop pressure controller; wherein, the multi-stage hydraulic cylinder is vertically erected at the center position of the instrument, and a plurality of sealing test devices are coaxially connected to each piston rod stage of the multi-stage hydraulic cylinder respectively. The multi-stage hydraulic cylinder is electrically connected and signal-connected to the closed-loop pressure controller, so that the closed-loop pressure controller controls the multi-stage hydraulic cylinder to drive a plurality of sealing test devices to move up and down separately or synchronously in the vertical direction; each sealing test device is provided with a multi-channel independent sealing cavity, and the water seepage detection array is annularly distributed on the lowest end plane of each sealing cavity. The water seepage detection array is composed of a humidity sensor and an image acquisition module; each humidity sensor and image acquisition module are electrically connected and signal-connected to the closed-loop pressure controller respectively, so that the closed-loop pressure controller can obtain the impedance change data of the humidity sensor and the crack image of the concrete specimen of the image acquisition module in real time, so as to dynamically adjust the output pressure gradient of the multi-stage pressurizing device; the multi-stage pressurizing device is arranged at the bottom of the instrument, and the multi-stage pressurizing device includes a high-precision hydraulic pump. The input end of the high-precision hydraulic pump is communicated with the hydraulic oil tank, the output end of the high-precision hydraulic pump is connected to the inlet of the pressure dividing valve group, and the respective outlets of the pressure dividing valve group are communicated with each sealing cavity respectively. The air cavity of the hydraulic oil tank is connected to the air pressure compensation unit; the high-precision hydraulic pump, the pressure dividing valve group and the air pressure compensation unit are electrically connected and signal-connected to the closed-loop pressure controller respectively. The closed-loop pressure controller is used to send a PWM speed regulation signal to the high-precision hydraulic pump to adjust the output flow rate in real time, to output a valve opening instruction to the pressure dividing valve group to achieve multi-channel independent pressure gradient control, and to drive the air pressure compensation unit to balance the hydraulic pulsation to control the gas-liquid pressure ratio, so that the closed-loop pressure controller dynamically adjusts the multi-stage pressurizing device according to the feedback data of the water seepage detection array.

[0005] Through the above technical solution, a plurality of sealing test devices are driven to lift separately or synchronously by a multi-stage hydraulic cylinder, and the pressure of each sealing cavity is independently controlled by combining with a pressure dividing valve group, so as to realize the parallel test of multiple concrete specimens and the controllable pressure gradient. The water seepage detection array integrates the impedance change detection of the humidity sensor and the crack analysis of the image acquisition module, so that the closed-loop pressure controller can determine the leakage point in real time and improve the water seepage identification accuracy. Based on the coordinated control of the air pressure compensation unit and the PWM speed regulation hydraulic pump of the closed-loop pressure controller, the gas-liquid pressure ratio can be automatically balanced and the hydraulic pulsation can be suppressed, so as to improve the test accuracy.

[0006] As a further illustration of the fully automatic concrete impermeability tester described in the present invention, preferably, a semiconductor temperature control module is provided around the periphery of each sealed cavity, and an annular flexible sealing ring is provided on the contact surface between each sealed cavity and the concrete specimen. A temperature sensor is embedded inside the flexible sealing ring. Each semiconductor temperature control module and temperature sensor are electrically connected and signal-connected to a closed-loop pressure controller respectively, so that the closed-loop pressure controller controls the semiconductor temperature control module according to the feedback data of the temperature sensor to keep the test environment temperature stable.

[0007] Through the above technical solution, the semiconductor temperature control module combined with the embedded temperature sensor constitutes a closed-loop temperature control system, which can accurately control the test environment temperature in the sealed cavity, eliminate the interference of temperature changes on the concrete permeability, and ensure the comparability of test data for different batches. The temperature sensor inside the flexible sealing ring monitors the temperature of the specimen contact surface in real time, avoiding seal failure caused by hydraulic heat generation or environmental temperature difference, and improving the sealing reliability of long-term tests. In addition, the test temperature can be quickly switched (such as -20°C to 80°C) through the semiconductor temperature control module to simulate the impermeability performance of concrete under freeze-thaw cycles or high-temperature environments, meeting diverse test requirements.

[0008] As a further illustration of the fully automatic concrete impermeability tester described in the present invention, preferably, each stage of the piston rod of the multi-stage hydraulic cylinder corresponds to an independent oil inlet and an independent oil return port, and the oil inlet and oil return port of each stage of the piston rod are both connected with an electro-hydraulic proportional valve for independently adjusting the flow rate and pressure of each stage of the oil circuit; a displacement sensor is installed on each stage of the piston rod for real-time detecting the telescopic stroke of the corresponding piston rod; a pressure sensor is provided at the end of each stage of the piston rod for monitoring the actual pressure on the concrete specimen. Each electro-hydraulic proportional valve, displacement sensor and pressure sensor are electrically connected and signal-connected to the closed-loop pressure controller respectively, so that the closed-loop pressure controller generates an independent PWM control signal according to the preset target pressure or displacement to drive the corresponding electro-hydraulic proportional valve, and separately adjusts or synchronously adjusts the extension or retraction speed and stroke of the corresponding piston rod according to the data feedback by the displacement sensor and the pressure sensor, so as to realize the precise positioning and constant pressure control of each stage of the piston rod.

[0009] Through the above technical solution, each stage of the piston rod is controlled by an independent oil circuit and an electro-hydraulic proportional valve. The closed-loop pressure controller dynamically adjusts the flow rate and pressure of each oil circuit through PWM signals to realize the independent or synchronous movement of different piston rods, improving the positioning accuracy. The displacement sensor monitors the piston rod stroke in real time, combined with the feedback data of the pressure sensor, to ensure uniform stress on the specimen, avoid seal failure or specimen damage caused by eccentric loading, and improve the accuracy of impermeability performance evaluation.

[0010] As a further illustration of the fully automatic concrete impermeability tester described in the present invention, preferably, a redundant standby valve group is connected in parallel to each stage of the oil circuit of the multi-stage hydraulic cylinder. The redundant standby valve group is electrically connected and signal-connected to the closed-loop pressure controller, so that when the electro-hydraulic proportional valve fails or the displacement sensor feedback is abnormal, the closed-loop pressure controller automatically switches to the redundant standby valve group.

[0011] Through the above technical solution, the redundant standby valve group and the main electro-hydraulic proportional valve form a dual-channel hydraulic control system. When it is detected that the main valve fails or the displacement / pressure feedback is abnormal, the closed-loop pressure controller can switch to the standby valve group to ensure that the test process is uninterrupted, improve the system reliability, and avoid test interruption or data loss caused by the failure of a single valve group.

[0012] As a further illustration of the fully automatic concrete impermeability tester described in the present invention, preferably, the humidity sensors of the water seepage detection array are arranged in a ring at equal intervals on the bottom surface of the sealed cavity; the image acquisition module includes a ring-shaped fill light and a macro camera. The axis of the lens of the macro camera coincides with the axis of the sealed cavity, and the ring-shaped fill light surrounds the outside of the macro camera; the ring-shaped fill light and the macro camera are respectively electrically connected and signal-connected to the closed-loop pressure controller, so that the closed-loop pressure controller dynamically adjusts the color temperature and brightness of the ring-shaped fill light according to the contrast of the crack images captured by the macro camera.

[0013] Through the above technical solution, the humidity sensors are arranged in a ring at equal intervals to ensure 360° dead-angle-free detection of the water seepage position and accurately locate the coordinates of the leakage point. The coaxial layout of the macro camera eliminates image distortion, and together with the dynamic adjustment of the ring-shaped fill light, it improves the resolution of crack recognition. The closed-loop pressure controller analyzes the image contrast in real time and automatically adjusts the color temperature and brightness of the ring-shaped fill light, which can eliminate the interference of water stain reflection or shadow and ensure the image clarity at different penetration stages (such as capillary water seepage and pressure gushing water).

[0014] As a further illustration of the fully automatic concrete impermeability tester described in the present invention, preferably, when the crack length of the concrete specimen captured by the macro camera exceeds a preset safety value, the closed-loop pressure controller is also used to trigger a step-down command to the multi-stage pressurizing device to reduce the water pressure in the corresponding sealed cavity.

[0015] Through the above technical solution, when the macro camera detects that the crack length of the concrete specimen exceeds a preset threshold, the closed-loop pressure controller reduces the water pressure by controlling the multi-stage pressurizing device, avoiding sudden bursting of the specimen or damage to the sealing structure, and improving the safety of the test.

[0016] As a further illustration of the fully automatic concrete impermeability tester of the present invention, preferably, a high-speed switching valve is provided between each outlet of the pressure dividing valve group and the sealed cavity, and each high-speed switching valve is electrically connected and signal-connected to the closed-loop pressure controller respectively, so that when the moisture sensor in any sealed cavity detects a sudden drop in impedance or the crack length exceeds the threshold value by the water seepage detection array, the closed-loop pressure controller controls the corresponding high-speed switching valve to close within a preset time, and activates the emergency pressure relief channel of the multi-stage pressurizing device to release the pressure of the sealed cavity, while maintaining the pressurized state of other sealed cavities.

[0017] Through the above technical solution, when the moisture sensor detects a sudden drop in impedance (such as a sudden change in water seepage) or the image recognition shows that the crack exceeds the limit, the closed-loop pressure controller can close the corresponding high-speed switching valve within a preset time, completely cut off the pressure supply of the faulty cavity, prevent the further deterioration of water seepage, and avoid damaging the pipeline by controlling the pressure of each sealed cavity, thus improving the service life of the instrument.

[0018] As a further illustration of the fully automatic concrete impermeability tester of the present invention, preferably, the closed-loop pressure controller is electrically connected and signal-connected to the data storage unit and the wireless communication module respectively. The data storage unit is used to record the data of the water seepage detection array, the multi-stage pressurizing device and the closed-loop pressure controller. The wireless communication module is used to wirelessly connect to the remote terminal to monitor the test process in real time and receive the impermeability performance scoring report generated by the closed-loop pressure controller.

[0019] Through the above technical solution, the data storage unit records the data of the water seepage detection array, the multi-stage pressurizing device and the closed-loop pressure controller in real time, ensuring the complete traceability of the experimental data. The wireless communication module supports 4G / 5G / Wi-Fi multi-mode transmission and can realize remote monitoring of the test through the remote terminal.

[0020] The beneficial effects of the present invention are as follows: The present invention drives multiple sealed test devices to lift independently or synchronously through multi-stage hydraulic cylinders, and combines the pressure dividing valve group to independently control the pressure of each sealed cavity, realizing the parallel test of multiple concrete specimens with a controllable pressure gradient. The water seepage detection array integrates the impedance change detection of the moisture sensor and the crack analysis of the image acquisition module, enabling the closed-loop pressure controller to determine the leakage point in real time and improving the accuracy of water seepage identification. Based on the collaborative control of the air pressure compensation unit and the PWM speed control hydraulic pump of the closed-loop pressure controller, the air-liquid pressure ratio can be automatically balanced and the hydraulic pulsation can be suppressed, improving the test accuracy. Description of the Drawings

[0021] Figure 1 is a schematic structural diagram of the fully automatic concrete impermeability tester of the present invention;

[0022] Figure 2 is a system architecture diagram of the fully automatic concrete impermeability tester of the present invention;

[0023] Figure 3 It is the temperature control block diagram of the sealing test device of the present invention;

[0024] Figure 4 It is the control block diagram of the multi-stage hydraulic cylinder of the present invention;

[0025] Figure 5 It is the control block diagram of the water seepage detection array of the present invention. Specific embodiments

[0026] In order to further understand the structure, features and other purposes of the present invention, the following is a detailed description with reference to the attached preferred embodiments and accompanying drawings. The embodiments described by these drawings are only used to illustrate the technical solutions of the present invention and do not limit the present invention.

[0027] As the first embodiment of the present invention, as Figure 1 shown, the present invention provides a fully automatic concrete impermeability tester, which includes a number of sealing test devices 1, multi-stage hydraulic cylinders 2, water seepage detection arrays 3, multi-stage pressurizing devices 4 and a closed-loop pressure controller 5.

[0028] The multi-stage hydraulic cylinder 2 is vertically erected at the center position of the instrument, and a number of sealing test devices 1 are respectively coaxially connected to each stage of piston rod of the multi-stage hydraulic cylinder 2. The multi-stage hydraulic cylinder 2 is electrically connected and signal-connected to the closed-loop pressure controller 5, so that the closed-loop pressure controller 5 controls the multi-stage hydraulic cylinder 2 to drive a number of sealing test devices 1 to move up and down independently or synchronously in the vertical direction.

[0029] Each sealing test device 1 is provided with a multi-channel independent sealing cavity 11, and the water seepage detection array 3 is annularly distributed on the lowest end plane of each sealing cavity 11. The water seepage detection array 3 is composed of a humidity sensor 31 and an image acquisition module 32. As Figure 2 shown, each humidity sensor 31 and image acquisition module 32 are respectively electrically connected and signal-connected to the closed-loop pressure controller 5, so that the closed-loop pressure controller 5 can obtain the impedance change data of the humidity sensor 31 and the crack images of the concrete specimens of the image acquisition module 32 in real time, so as to dynamically adjust the output pressure gradient of the multi-stage pressurizing device 4.

[0030] The multi-stage pressurizing device 4 is arranged at the bottom of the instrument. The multi-stage pressurizing device 4 includes a high-precision hydraulic pump 41. The input end of the high-precision hydraulic pump 41 is communicated with a hydraulic oil tank, the output end of the high-precision hydraulic pump 41 is connected to the inlet of a pressure dividing valve group 42, and the respective outlets of the pressure dividing valve group 42 are respectively communicated with each sealing cavity 11. The air cavity of the hydraulic oil tank is connected to a pneumatic compensation unit 43. As Figure 2As shown, the high-precision hydraulic pump 41, the pressure-dividing valve group 42, and the air pressure compensation unit 43 are respectively electrically connected and signal-connected to the closed-loop pressure controller 5. The closed-loop pressure controller 5 is used to send a PWM speed regulation signal to the high-precision hydraulic pump 41 to adjust the output flow rate in real time, to output a valve opening instruction to the pressure-dividing valve group 42 to achieve multi-channel independent pressure gradient control, and to drive the air pressure compensation unit 43 to balance the hydraulic pulsation to control the gas-liquid pressure ratio, so that the closed-loop pressure controller 5 dynamically adjusts the multi-stage pressurizing device 4 according to the feedback data of the water seepage detection array 3.

[0031] In this embodiment, the multi-stage hydraulic cylinder is used to drive multiple sealing test devices to lift individually or synchronously, and the pressure-dividing valve group is combined to independently control the pressure of each sealing cavity, so as to realize the parallel test of multiple concrete specimens with a controllable pressure gradient. The water seepage detection array integrates the impedance change detection of the humidity sensor and the crack analysis of the image acquisition module, so that the closed-loop pressure controller can determine the leakage point in real time and improve the water seepage identification accuracy. Based on the coordinated control of the air pressure compensation unit and the PWM speed regulation hydraulic pump of the closed-loop pressure controller, the gas-liquid pressure ratio can be automatically balanced and the hydraulic pulsation can be suppressed, improving the test accuracy.

[0032] Before the test, turn on the power supply and start the closed-loop pressure controller 5. The system self-checks whether each module such as the multi-stage hydraulic cylinder 2, the water seepage detection array 3, and the multi-stage pressurizing device 4 is normal. If each module is normal, the sealing test device 1 can be operated to lift, otherwise the sealing test device 1 cannot be operated to lift, and the system gives a prompt. When the system is in normal use, place the concrete specimen into the sealing cavity 11 of the sealing test device 1, ensure that the contact surface between the specimen and the bottom of the cavity is flat, and complete the installation of the specimen. Control the multi-stage hydraulic cylinder 2 by the closed-loop pressure controller 5 to drive the sealing test device 1 to press down, so that the specimen and the sealing cavity 11 form a sealed space.

[0033] When conducting the test, the closed-loop pressure controller 5 first controls the low-pressure mode of the multi-stage pressurization device 4 to inject a small amount of water into the sealed cavity 11. The initial humidity is detected by the humidity sensor 31 of the water seepage detection array 3. After confirming no leakage, it enters the pressurization stage. Then, the closed-loop pressure controller 5 sends a PWM speed regulation signal to the high-precision hydraulic pump 41 to adjust the flow rate according to the preset pressure gradient, and distributes different pressures to each sealed cavity 11 through the pressure dividing valve group 42. During this process, the air pressure compensation unit 43 balances the hydraulic pulsation in real time to keep the gas-liquid pressure ratio stable. During the test, the humidity sensor 31 of the water seepage detection array 3 continuously monitors the change in the bottom impedance of the specimen, and the data is transmitted to the closed-loop pressure controller 5 in real time. The image acquisition module 32 captures the crack image on the surface of the specimen and analyzes the crack propagation. If water seepage (sudden increase in humidity) or crack propagation is detected, the closed-loop pressure controller 5 immediately reduces the pressure of the corresponding cavity (by adjusting the opening of the pressure dividing valve group 42). If there is no leakage in the specimen, the pressure is gradually increased step by step according to the gradient until the set threshold is reached or the specimen is damaged. When the specimen penetrates or the pressure reaches the preset upper limit, the system stops pressurization, and the multi-stage hydraulic cylinder 2 automatically raises the sealing test device 1. The closed-loop pressure controller 5 outputs the final pressure value, water seepage time, crack image, and humidity change curve to generate an impermeability performance report. Finally, the water in the sealed cavity 11 is drained, and the humidity sensor 31 and the image acquisition module 32 are cleaned. The hydraulic pump 41 is turned off, the pressure dividing valve group 42 is reset, and the power is cut off after the equipment cools down. The entire test can be fully automated under the control of the closed-loop pressure controller 5. The pressure can be accurately adjusted through closed-loop control, and the test accuracy and efficiency are ensured by combining multi-sensor feedback.

[0034] As the second embodiment of the present invention, as Figure 3 shown, a semiconductor temperature control module 12 is provided on the periphery of each sealed cavity 11, and a ring-shaped flexible sealing ring is provided on the contact surface between each sealed cavity 11 and the concrete specimen. A temperature sensor 13 is embedded in the inner side of the flexible sealing ring. Each semiconductor temperature control module 12 and temperature sensor 13 are electrically connected and signal-connected to the closed-loop pressure controller 5 respectively, so that the closed-loop pressure controller 5 controls the semiconductor temperature control module 12 according to the feedback data of the temperature sensor 12 to keep the test environment temperature stable, such as controlling the temperature to be maintained at 20±1°C.

[0035] In this embodiment, the semiconductor temperature control module 12 and the embedded temperature sensor 13 form a closed-loop temperature control system, which can accurately control the temperature of the test environment in the sealed cavity 11, eliminate the interference of temperature changes on the concrete permeability, and ensure the comparability of test data for different batches. The temperature sensor 13 inside the flexible sealing ring monitors the temperature of the specimen contact surface in real time, avoiding seal failure caused by hydraulic heat generation or environmental temperature difference, and improving the seal reliability of long-term tests. In addition, the test temperature can be quickly switched (such as -20°C to 80°C) through the semiconductor temperature control module 12 to simulate the anti-seepage performance of concrete under freeze-thaw cycles or high-temperature environments, meeting diverse test requirements. Before the test and before the specimen is installed, the closed-loop pressure controller 5 first reads the initial data of the temperature sensor 13. If the ambient temperature deviates from the set value (such as 20 ± 1°C), the semiconductor temperature control module 12 is started for heating or cooling until the temperature is stable. During the test, the closed-loop pressure controller 5 monitors the data of the humidity sensor 31 and the temperature sensor 13 simultaneously to ensure no leakage and stable temperature. If water seepage or abnormal temperature is detected, the closed-loop pressure controller 5 automatically reduces the pressure of the corresponding cavity or adjusts the working mode of the temperature control module 12 to ensure that the test conditions meet the standards (such as 20 ± 1°C). When the specimen penetrates, the pressure reaches the upper limit, or the temperature exceeds the allowable range, the system stops pressurizing and raises the sealed test device 1.

[0036] As the third embodiment of the present invention, as Figure 4 shown, each stage of the piston rod of the multi-stage hydraulic cylinder 2 corresponds to an independent oil inlet and an oil return port, and the oil inlet and the oil return port of each stage of the piston rod are both connected with an electro-hydraulic proportional valve 21 for independently adjusting the flow rate and pressure of each stage of the oil circuit; a displacement sensor 22 is installed on each stage of the piston rod for real-time detection of the telescopic stroke of the corresponding piston rod; a pressure sensor 23 is arranged at the end of each stage of the piston rod for monitoring the actual pressure on the concrete specimen. Each electro-hydraulic proportional valve 21, displacement sensor 22, and pressure sensor 23 are electrically connected and signal-connected to the closed-loop pressure controller 5 respectively, so that the closed-loop pressure controller 5 generates an independent PWM control signal according to the preset target pressure or displacement to drive the corresponding electro-hydraulic proportional valve 21, and separately adjusts or synchronously adjusts the extension or retraction speed and stroke of the corresponding piston rod according to the data fed back by the displacement sensor 22 and the pressure sensor 23 to achieve precise positioning and constant pressure control of each stage of the piston rod.

[0037] In this embodiment, each stage of the piston rod adopts an independent oil circuit and is controlled by an electro-hydraulic proportional valve 21. The closed-loop pressure controller 5 dynamically adjusts the flow rate and pressure of each oil circuit through PWM signals to achieve the individual or synchronous movement of different piston rods, thereby improving the positioning accuracy. The displacement sensor 22 monitors the piston rod stroke in real time, and combines with the feedback data of the pressure sensor 23 to ensure uniform stress on the test piece, avoid seal failure or test piece breakage caused by eccentric load, and improve the accuracy of anti-seepage performance evaluation. After the test piece is installed, the closed-loop pressure controller 5 sends PWM signals to each electro-hydraulic proportional valve 21 according to the preset downward stroke to independently adjust the downward speed of each stage of the piston rod, so that the test piece is uniformly compressed. The pressure sensor 23 monitors the stress on the test piece in real time. If the pressure of a certain stage is insufficient, the oil inlet flow rate of the corresponding oil circuit is increased; if the pressure exceeds the limit, the flow rate is decreased or the oil is returned briefly. The displacement sensor 22 synchronously detects the position of the piston rod to prevent eccentric pressure on the test piece caused by non-synchronization. When the pressure reaches the sealing threshold (such as 0.5 MPa) and the displacement is stable, the system determines that the sealing is completed. During the test, the closed-loop pressure controller 5 adjusts each electro-hydraulic proportional valve 21 according to the preset pressure curve (such as 0.1 MPa / 5 min), and injects water into the sealing cavity 11 through the pressure dividing valve group 42 to increase the pressure. The data of the pressure sensor 23 is fed back in real time. If the pressure of a certain stage fluctuates, the opening of the corresponding electro-hydraulic proportional valve 21 or the rotation speed of the hydraulic pump 41 is adjusted to maintain a constant pressure.

[0038] As the fourth embodiment of the present invention, as Figure 4 shown, a redundant standby valve group 24 is connected in parallel to each oil circuit of the multi-stage hydraulic cylinder 2. The redundant standby valve group 24 is electrically connected and signal-connected to the closed-loop pressure controller 5, so that when the electro-hydraulic proportional valve 21 fails or the displacement sensor 22 feedback is abnormal, the closed-loop pressure controller 5 automatically switches to the redundant standby valve group 24.

[0039] In this embodiment, the redundant standby valve group 24 and the main electro-hydraulic proportional valve 21 form a dual-channel hydraulic control system. When a main valve failure or abnormal displacement / pressure feedback is detected, the closed-loop pressure controller 5 can switch to the standby valve group to ensure the uninterrupted test process, improve the system reliability, and avoid test interruption or data loss caused by the failure of a single valve group. Before the test, after the system starts, the closed-loop pressure controller 5 will confirm that the standby valve group 24 is in the standby state and the oil circuit pressure is normal. During the sealing and pressurization process, if the data of a certain stage displacement sensor 22 is abnormal (such as signal loss or out-of-tolerance), or the electro-hydraulic proportional valve 21 fails to respond, the closed-loop controller 5 immediately closes the oil circuit of the faulty valve group, switches to the redundant standby valve group 24, and recalibrates the pressure and displacement of the piston rod at this stage to continue the test. During the test process, the closed-loop pressure controller 5 controls each oil circuit according to the preset pressure gradient, and the redundant standby valve group 24 is in the hot standby state. If the pressure fluctuation of the main valve group exceeds the limit (such as ±0.05 MPa) and the adjustment is ineffective, the system automatically switches to the standby valve group 24 and records the fault information. In addition, the closed-loop controller 5 will send test signals regularly to ensure that the standby valve group 24 can be enabled at any time.

[0040] As the fifth embodiment of the present invention, as Figure 5 shown, the humidity sensors 31 of the water seepage detection array 3 are arranged in a circular shape at equal intervals on the bottom surface of the sealing cavity 11; the image acquisition module 32 includes an annular supplementary light 321 and a macro camera 322. The optical axis of the macro camera 322 coincides with the axis of the sealing cavity 11, and the annular supplementary light 321 surrounds the outside of the macro camera 322; the annular supplementary light 321 and the macro camera 322 are electrically connected and signal-connected to the closed-loop pressure controller 5 respectively, so that the closed-loop pressure controller 5 dynamically adjusts the color temperature and brightness of the annular supplementary light 321 according to the contrast of the crack images collected by the macro camera 322.

[0041] In this embodiment, the humidity sensors 31 are arranged in a circular shape at equal intervals to ensure 360° dead-angle-free detection of the water seepage position and accurately locate the coordinates of the leakage point. The macro cameras 322 are coaxially arranged to eliminate image distortion. With the dynamic adjustment of the annular supplementary light 321, the resolution of crack identification is improved. The closed-loop pressure controller 5 analyzes the image contrast in real time and automatically adjusts the color temperature and brightness of the annular supplementary light 321, which can eliminate the reflection of water stains or shadow interference and ensure the image clarity at different seepage stages (such as capillary water seepage and pressure gushing water).

[0042] Before the test, the macro camera 322 captures an image of the initial state of the bottom surface of the test piece under optimized lighting conditions. The system automatically analyzes the image contrast and dynamically adjusts the parameters of the ring fill light 321 to ensure the crack detection sensitivity. During the test, the macro camera 322 continuously performs image acquisition, and the closed-loop pressure controller 5 analyzes the image features in real time. When a suspected crack is detected, the brightness of the ring fill light 321 is automatically increased (up to 150% of the reference value), the color temperature is adjusted to 4500K (optimal crack contrast), and the high-definition continuous shooting mode (5 frames per second) is triggered.

[0043] As the sixth embodiment of the present invention, the closed-loop pressure controller 5 is further configured to trigger a step-down instruction to the multi-stage pressurizing device 4 when the crack length of the concrete test piece captured by the macro camera 322 exceeds a preset safety value, so as to reduce the water pressure in the corresponding sealed cavity 11.

[0044] In this embodiment, when the macro camera 322 detects that the crack length of the concrete test piece exceeds a preset threshold (such as 5 mm), the closed-loop pressure controller 5 reduces the water pressure by controlling the multi-stage pressurizing device 4 (such as reducing the pressure by 0.2 MPa each time), avoiding sudden bursting of the test piece or damage to the sealing structure, and improving the safety of the test. The step-down pressure reduction can be set to a warning stage (cracks 3 - 5 mm), the closed-loop controller 5 triggers an audible and visual alarm, automatically increases the image acquisition frequency to 2 frames per second, and records the current pressure value as the initial cracking pressure; the first-stage pressure reduction (cracks 5 - 7 mm), the controller sends an instruction to the multi-stage pressurizing device (4), such as the pressure dividing valve group 42 reduces the opening degree by 10% step by step and the pressure in the corresponding sealed cavity 11 is reduced by 0.2 MPa, and maintains the state after the pressure reduction for observation for 3 minutes; the second-stage emergency pressure reduction (cracks > 7 mm), immediately starts a rapid pressure reduction program, such as the high-precision hydraulic pump 41 rotates at the lowest speed, the pressure dividing valve group 42 switches to the pressure relief mode, and the pressure is reduced to a safe value (below 0.5 MPa) within 30 seconds, etc.

[0045] As the seventh embodiment of the present invention, as Figure 1 shown, a high-speed switching valve 44 is provided between each outlet of the pressure dividing valve group 42 and the sealed cavity 11. Each high-speed switching valve 44 is electrically connected and signal-connected to the closed-loop pressure controller 5 respectively, so that when the moisture sensor 31 in any sealed cavity 11 detected by the water seepage detection array 3 has a sudden drop in impedance or the crack length exceeds the threshold, the closed-loop pressure controller 5 controls the corresponding high-speed switching valve 44 to close within a preset time (such as within 50 ms), and starts the emergency pressure relief channel of the multi-stage pressurizing device 4 to release the pressure in the sealed cavity 11, while maintaining the pressurized state of other sealed cavities 11.

[0046] Through the above technical solution, when the humidity sensor 31 detects a sudden drop in impedance (such as a sudden change in water seepage) or the image recognition shows that the crack exceeds the limit, the closed-loop pressure controller 5 can close the corresponding high-speed switching valve 44 within a preset time, completely cut off the pressure supply of the faulty cavity, prevent the further deterioration of water seepage, and avoid damaging the pipeline by controlling the pressure of each sealed cavity, thus improving the service life of the instrument. The high-speed switching valve 44 can adopt a normally closed solenoid valve, which automatically closes when powered off to ensure that the pressure can be blocked even in case of control failure of the closed-loop pressure controller 5.

[0047] As the eighth embodiment of the present invention, as Figure 2 shown, the closed-loop pressure controller 5 is electrically connected and signal-connected to the data storage unit 51 and the wireless communication module 52 respectively. The data storage unit 51 is used to record the data of the water seepage detection array 3, the multi-stage pressurizing device 4 and the closed-loop pressure controller 5. The wireless communication module 52 is used to wirelessly connect to the remote terminal 6 to monitor the test process in real time and receive the anti-seepage performance scoring report generated by the closed-loop pressure controller 5.

[0048] In this embodiment, the data storage unit 51 records the data of the water seepage detection array 3, the multi-stage pressurizing device 4 and the closed-loop pressure controller 5 in real time, such as full-dimensional test parameters such as water seepage rate, pressure curve, crack image, temperature control data, etc., to ensure the complete traceability of the experimental data. The wireless communication module 52 supports 4G / 5G / Wi-Fi multi-mode transmission, and can view key data such as pressure fluctuation and water seepage alarm in real time through the remote terminal 6 (such as a PC or a tablet) to realize remote monitoring of the test.

[0049] It should be noted that the above invention content and specific implementation manners are intended to prove the practical application of the technical solution provided by the present invention, and should not be construed as a limitation on the protection scope of the present invention. Those skilled in the art can make various modifications, equivalent replacements or improvements within the spirit and principle of the present invention. The protection scope of the present invention shall be subject to the appended claims.

Claims

1. An automatic concrete impermeability tester, characterized in that, It includes several seal testing devices (1), multi-stage hydraulic cylinders (2), water seepage detection arrays (3), multi-stage pressurizing devices (4), and a closed-loop pressure controller (5); among them, The multi-stage hydraulic cylinders (2) are vertically installed at the center position of the instrument. Several seal testing devices (1) are respectively coaxially connected to the piston rods of each stage of the multi-stage hydraulic cylinders (2). The multi-stage hydraulic cylinders (2) are electrically connected and signal-connected to the closed-loop pressure controller (5), so that the closed-loop pressure controller (5) controls the multi-stage hydraulic cylinders (2) to drive several seal testing devices (1) to move up and down independently or synchronously in the vertical direction; Each seal testing device (1) is provided with a multi-channel independent seal cavity (11). The water seepage detection arrays (3) are annularly distributed on the lowest end plane of each seal cavity (11). The water seepage detection arrays (3) are composed of humidity sensors (31) and image acquisition modules (32); each humidity sensor (31) and image acquisition module (32) are respectively electrically connected and signal-connected to the closed-loop pressure controller (5), so that the closed-loop pressure controller (5) can obtain the impedance change data of the humidity sensors (31) and the crack images of the concrete specimens of the image acquisition modules (32) in real time, and dynamically adjust the output pressure gradient of the multi-stage pressurizing device (4); The multi-stage pressurizing device (4) is arranged at the bottom of the instrument. The multi-stage pressurizing device (4) includes a high-precision hydraulic pump (41). The input end of the high-precision hydraulic pump (41) is communicated with the hydraulic oil tank. The output end of the high-precision hydraulic pump (41) is connected to the inlet of the pressure dividing valve group (42). The respective outlets of the pressure dividing valve group (42) are respectively communicated with each seal cavity (11). The air cavity of the hydraulic oil tank is connected to the air pressure compensation unit (43); the high-precision hydraulic pump (41), the pressure dividing valve group (42), and the air pressure compensation unit (43) are respectively electrically connected and signal-connected to the closed-loop pressure controller (5). The closed-loop pressure controller (5) is used to send a PWM speed regulation signal to the high-precision hydraulic pump (41) to adjust the output flow rate in real time, to output a valve opening instruction to the pressure dividing valve group (42) to achieve multi-channel independent pressure gradient control, and to drive the air pressure compensation unit (43) to balance the hydraulic pulsation to control the gas-liquid pressure ratio, so that the closed-loop pressure controller (5) dynamically adjusts the multi-stage pressurizing device (4) according to the feedback data of the water seepage detection array (3).

2. The fully automatic concrete impermeability tester according to claim 1, wherein A semiconductor temperature control module (12) is provided on the periphery of each seal cavity (11), and an annular flexible seal ring is provided on the contact surface between each seal cavity (11) and the concrete specimen. A temperature sensor (13) is embedded inside the flexible seal ring. Each semiconductor temperature control module (12) and temperature sensor (13) are respectively electrically connected and signal-connected to the closed-loop pressure controller (5), so that the closed-loop pressure controller (5) controls the semiconductor temperature control module (12) according to the feedback data of the temperature sensor (12) to keep the test environment temperature stable.

3. The fully automatic concrete impermeability tester according to claim 1, characterized in that, Each stage of the piston rod of the multi-stage hydraulic cylinder (2) corresponds to an independent oil inlet and an independent oil return port to form independent oil circuits. The oil inlet and the oil return port of each stage of the piston rod are both connected with an electro-hydraulic proportional valve (21) for independently adjusting the flow rate and pressure of each stage of the oil circuit. A displacement sensor (22) is installed on each stage of the piston rod for real-time detection of the telescopic stroke of the corresponding piston rod. A pressure sensor (23) is arranged at the end of each stage of the piston rod for monitoring the actual pressure exerted on the concrete specimen. Each electro-hydraulic proportional valve (21), displacement sensor (22) and pressure sensor (23) are respectively electrically connected and signal-connected to the closed-loop pressure controller (5), so that the closed-loop pressure controller (5) generates an independent PWM control signal according to the preset target pressure or displacement to drive the corresponding electro-hydraulic proportional valve (21), and separately adjusts or synchronously adjusts the extension or retraction speed and stroke of the corresponding piston rod according to the data fed back by the displacement sensor (22) and the pressure sensor (23), so as to realize the precise positioning and constant pressure control of each stage of the piston rod.

4. The fully automatic concrete impermeability tester according to claim 3, wherein, A redundant standby valve group (24) is connected in parallel to each stage of the oil circuit of the multi-stage hydraulic cylinder (2). The redundant standby valve group (24) is electrically connected and signal-connected to the closed-loop pressure controller (5), so that when the electro-hydraulic proportional valve (21) fails or the displacement sensor (22) feeds back abnormally, the closed-loop pressure controller (5) automatically switches to the redundant standby valve group (24).

5. The fully automatic concrete impermeability tester according to claim 1, wherein The humidity sensors (31) of the water seepage detection array (3) are arranged in an annular and equally spaced manner on the bottom surface of the sealed cavity (11). The image acquisition module (32) includes an annular supplementary light (321) and a macro camera (322). The optical axis of the macro camera (322) coincides with the axis of the sealed cavity (11). The annular supplementary light (321) surrounds the outside of the macro camera (322). The annular supplementary light (321) and the macro camera (322) are respectively electrically connected and signal-connected to the closed-loop pressure controller (5), so that the closed-loop pressure controller (5) dynamically adjusts the color temperature and brightness of the annular supplementary light (321) according to the contrast of the crack image collected by the macro camera (322).

6. The fully automatic concrete impermeability tester according to claim 5, wherein, The closed-loop pressure controller (5) is also used to trigger a step-down command to the multi-stage pressurizing device (4) when the crack length of the concrete specimen captured by the macro camera (322) exceeds the preset safety value, so as to reduce the water pressure of the corresponding sealed cavity (11).

7. The fully automatic concrete impermeability tester according to claim 1, wherein, A high-speed switch valve (44) is provided between each outlet of the pressure dividing valve group (42) and the sealed cavity (11). Each high-speed switch valve (44) is respectively electrically connected and signal-connected to the closed-loop pressure controller (5), so that when the water seepage detection array (3) detects that the impedance of the humidity sensor (31) of any sealed cavity (11) drops suddenly or the crack length exceeds the threshold value, the closed-loop pressure controller (5) controls the corresponding high-speed switch valve (44) to close within the preset time, and starts the emergency pressure relief channel of the multi-stage pressurizing device (4) to release the pressure of the sealed cavity (11), while maintaining the pressurized state of other sealed cavities (11).

8. The fully automatic concrete impermeability tester according to claim 1, characterized in that, The closed-loop pressure controller (5) is electrically and signal-connected to the data storage unit (51) and the wireless communication module (52) respectively. The data storage unit (51) is used to record the data of the water seepage detection array (3), the multi-stage pressurization device (4) and the closed-loop pressure controller (5). The wireless communication module (52) is used to wirelessly connect to the remote terminal (6) to monitor the test process in real time and receive the anti-seepage performance score report generated by the closed-loop pressure controller (5).

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