Hydraulic oil cylinder convergence experiment device and operation method thereof

Abstract

The invention relates to the technical field of hydraulic oil cylinder convergence experiments, in particular to a hydraulic oil cylinder convergence experiment device and an operation method thereof, and the experiment device comprises a frame system, a fixing system, a hydraulic system, a sensor system and a control system. The hydraulic oil cylinder convergence experiment device is used in the operation method. By means of the innovative throttling control, real-time monitoring, loading and fixing structure and the operation method thereof, the defects and deficiencies of speed control precision, real-time monitoring, universality and safety in the prior art are overcome, and then the detection precision, the experiment efficiency, the data integrity and the safety guarantee are improved.

Description

Technical Field

[0001] This invention relates to the field of hydraulic cylinder convergence test technology, and in particular to a hydraulic cylinder convergence test device and its operation method. Background Technology

[0002] With the rapid development of my country's equipment manufacturing industry, large-scale engineering machinery has experienced rapid development and widespread adoption. Hydraulic cylinders, the core actuators that convert hydraulic energy into mechanical energy, are widely used in various applications due to their simple structure, high output force, and smooth transmission. These applications include hydraulic support columns in mining, excavator bucket cylinders in engineering machinery, tower crane luffing cylinders in construction machinery, and lifting mechanisms in heavy vehicles. Since these devices often require reliable and stable power output from hydraulic cylinders, high demands are placed on their operational performance and quality. In these applications, the convergence (buffering) of the hydraulic cylinder directly determines the safety and stability of the equipment. Examples include the retraction process of a mining hydraulic support under roof pressure and the smoothness of lowering an excavator bucket. If the convergence speed of the hydraulic cylinder is out of control or its buffering performance is insufficient, it can easily lead to equipment impact vibration, accelerated component wear, and even safety accidents. Therefore, accurate testing of the convergence (buffering) of hydraulic cylinders is crucial. After the processing and manufacturing of hydraulic cylinders are completed, the relevant performance of hydraulic cylinders must be inspected before leaving the factory to verify whether the relevant performance indicators of hydraulic cylinders meet the design requirements. In order to verify these performance indicators, the hydraulic cylinders need to be tested by relevant testing equipment.

[0003] Existing technologies for testing the convergence (buffering) of hydraulic cylinders are insufficient to meet the requirements for high-precision and high-reliability testing, and have the following drawbacks:

[0004] 1. Low precision in convergence speed control: Existing technologies partially rely on the relief valve or directional valve of the hydraulic cylinder's own hydraulic system to regulate the flow rate, which cannot achieve uniform speed control during the retraction process, and is prone to speed fluctuations, resulting in distorted buffer performance evaluation data; some technologies use manual adjustment of the hydraulic circuit, which has large human error and cannot cope with the compatibility testing of different specifications of cylinders.

[0005] 2. Lagging and discontinuous speed monitoring: Existing technologies mostly calculate the average speed by using a stopwatch to time the cylinder stroke and a ruler to measure it. This cannot capture the instantaneous speed changes during the retraction process in real time, and it is difficult to monitor the speed fluctuations in the buffer section when the cylinder approaches the end of its stroke. It cannot fully reflect the dynamic characteristics of convergence (buffering).

[0006] 3. Poor versatility of experimental setup: Existing technologies are mostly designed for specific models of hydraulic cylinders, with fixed frame structures, which cannot be flexibly adapted to hydraulic cylinders of different diameters and strokes, resulting in high experimental costs; moreover, there is a lack of standardized throttling control components, making it difficult to reproduce experimental parameters and resulting in insufficient comparability and authority of experimental results.

[0007] 4. High safety risks: In the absence of stable loading control, the existing technology directly drives the hydraulic cylinder to retract. If the pressure in the hydraulic circuit changes suddenly, it can easily cause the hydraulic cylinder to "jump," which not only affects the experimental data but may also cause equipment collisions or component damage, posing a safety hazard.

[0008] In summary, the shortcomings of existing technologies in speed control, real-time monitoring, versatility, and safety can no longer meet the current demand for high-precision performance testing of hydraulic cylinders. There is an urgent need for a convergence (buffering) experimental device and its operation method that is simple in structure, precise in control, real-time in monitoring, and highly versatile, so as to solve the problems existing in the current technologies. Summary of the Invention

[0009] (a) Technical problems to be solved

[0010] In view of the shortcomings and deficiencies of existing technologies in terms of speed control accuracy, real-time monitoring, versatility and safety, the present invention provides a hydraulic cylinder convergence test device and its operation method, which solves the technical problems existing in traditional equipment and methods.

[0011] (II) Technical Solution

[0012] To achieve the above objectives, a hydraulic cylinder convergence experimental device is provided, comprising: a frame system, a fixing system, a hydraulic system, a sensor system, and a control system;

[0013] The frame system is integrally formed from high-strength alloy steel and is detachably connected. It has a horizontal gantry shape and includes: longitudinal beams, a first end crossbeam, a bottom end crossbeam, an external loading device, a first end crossbeam mounting device, and a bottom end crossbeam mounting device. One end of the longitudinal beam is located on the left and right sides of the bottom end crossbeam, and the other end of the longitudinal beam is movably connected to the first end crossbeam. The first end crossbeam mounting device and the bottom end crossbeam mounting device are arranged opposite each other and are detachably connected to the first end crossbeam and the bottom end crossbeam, respectively. The external loading device is connected to the bottom end crossbeam and drives it to move along the longitudinal beam.

[0014] The fixing system includes: a hydraulic cylinder fixing seat, a cylinder rod fixing seat, and a limiting buffer. The hydraulic cylinder fixing seat is connected to the bottom crossbeam mounting device. The hydraulic cylinder fixing seat is equipped with an adjustable mounting frame to adapt to the fixing requirements of cylinders with different diameters. The cylinder rod fixing seat is connected to the front crossbeam mounting device and has an anti-slip bushing inside to adapt to the fixing requirements of hydraulic rods with different diameters. The limiting buffer is fixed at the hydraulic cylinder fixing seat at the retracted end position of the hydraulic cylinder under test to prevent excessive retraction of the cylinder and damage to the components due to collision.

[0015] The hydraulic system includes: a throttle joint, a hydraulic pump, high-pressure hydraulic pipelines, a hydraulic oil tank, an externally loaded hydraulic cylinder, and a directional valve. The throttle joint is detachably connected to the hydraulic oil inlet and outlet of the hydraulic cylinder under test. The throttle joint is connected to the directional valve via high-pressure hydraulic pipelines. The directional valve is connected to the hydraulic pump and the hydraulic oil tank via high-pressure hydraulic pipelines. The hydraulic oil inlet and outlet of the externally loaded hydraulic cylinder are connected to the hydraulic pump via the high-pressure hydraulic pipelines.

[0016] The sensor system includes a displacement sensor, a video sensor, and a pressure sensor. The displacement sensor is installed on the longitudinal beam to measure its relative displacement with respect to the bottom crossbeam. The pressure sensor is installed at the hydraulic oil inlet and outlet of the hydraulic cylinder under test and the externally loaded hydraulic cylinder. The video sensor is installed on the bottom crossbeam to monitor the position of the hydraulic cylinder under test in real time.

[0017] The control system is electrically connected to the sensor system and the hydraulic system, realizing integrated control of speed regulation, data acquisition, curve generation and safety warning.

[0018] This invention provides a hydraulic cylinder convergence test device that, by utilizing innovative throttling control, real-time monitoring, loading and fixing structures, overcomes the shortcomings and deficiencies of existing technologies in terms of speed control accuracy, real-time monitoring, versatility and safety, thereby improving detection accuracy, experimental efficiency, data integrity and safety assurance.

[0019] Preferably, the control system includes: a PLC controller, a human-machine interface module, and a data acquisition module; the PLC controller is electrically connected to the human-machine interface module, the data acquisition module, the hydraulic pump, and the directional valve; the data acquisition module is electrically connected to the sensor system; and the operator operates the human-machine interface module.

[0020] Preferably, the longitudinal beam is provided with a slide rail, and the first end crossbeam and the bottom end crossbeam can slide on the slide rail; the longitudinal beam is provided with a pin hole, and the first end crossbeam is provided with a corresponding pin hole, so as to fix the relative position of the first end crossbeam and the longitudinal beam by means of a pin shaft.

[0021] Preferably, the external loading force device is driven by an external loading force hydraulic cylinder to drive the bottom crossbeam, and the stroke of the bottom crossbeam is 500-3000mm; the limiting buffer adopts a combination structure of elastic buffer block and rigid limiting plate; the diameter of the throttling orifice of the throttling connector is 0.5-5mm, which can be quickly replaced according to the flow requirements of different tested hydraulic cylinders.

[0022] Preferably, the hydraulic system further includes a relief valve, which is disposed at the hydraulic oil inlet and outlet of the pressure sensor located in the hydraulic cylinder under test and the externally loaded hydraulic cylinder.

[0023] Preferably, the displacement sensor is a wire-type displacement sensor, and the displacement sensor, video sensor, and pressure sensor transmit measurement data to the data acquisition module in real time via wires or wirelessly.

[0024] Preferably, the mounting frame of the hydraulic cylinder mounting base has upper and lower parts. The lower mounting frame is fixed to one end of the hydraulic cylinder mounting base, and the upper mounting frame moves up and down in the vertical direction under the drive of the hydraulic cylinder. It is equipped with an anti-slip bushing to adapt to the fixing requirements of hydraulic cylinders with different diameters.

[0025] An operating method for the above-mentioned hydraulic cylinder convergence test device includes the following steps:

[0026] S1: Experimental Preparation and Debugging Phase

[0027] S01: Based on the cylinder diameter and stroke of the hydraulic cylinder being tested, adjust the spacing between the longitudinal beams of the frame system, adjust the position of the first end crossbeam, and fix the position of the first end crossbeam and longitudinal beams with pins.

[0028] S02: Place the cylinder body of the hydraulic cylinder to be tested on the lower mounting frame, adjust the upper mounting frame to fix the cylinder body, and fix the cylinder rod of the hydraulic cylinder to be tested in the cylinder rod end fixing seat of the first end crossbeam to ensure that the axis of the hydraulic cylinder to be tested coincides with the center line of the frame system.

[0029] S03: Select a throttle connector with the corresponding orifice diameter and install it on the hydraulic oil inlet and outlet of the hydraulic cylinder respectively. The throttle connector is connected to the directional valve through a high-pressure hydraulic pipeline. The directional valve is connected to the hydraulic pump and the hydraulic oil tank through a high-pressure hydraulic pipeline.

[0030] S04: Install the wire-type displacement sensor on the longitudinal beam, fix the wire end to the bottom crossbeam, and perform zero-point calibration to ensure the calibration accuracy reaches ±0.1mm;

[0031] S05: Start the hydraulic pump and run it under no-load, preset the loading pressure and target retraction speed, adjust the relief valve to the corresponding pressure threshold, and complete the hydraulic system debugging;

[0032] S2: Parameter preset and system startup phase:

[0033] S21: Input experimental parameters into the human-machine interaction module, set safety protection thresholds, and save them to the PLC controller;

[0034] S22: Start the hydraulic system to ensure that the loading force is applied evenly to the cylinder piston rod; the control system adjusts the opening of the throttle connector through the PLC controller to perform a pre-retraction test on the hydraulic cylinder under test. If the speed fluctuation exceeds the preset threshold, the opening of the throttle connector is finely adjusted.

[0035] S23: Activate the safety early warning module of the control system to ensure timely response in case of abnormal situations during the experiment;

[0036] S3: Experimental Operation and Data Acquisition Phase:

[0037] S31: The directional valve quickly switches to the retraction position, and the hydraulic oil is precisely controlled by the throttle joint to drive the detected hydraulic cylinder to retract at a uniform speed; the external loading force device maintains a stable loading pressure, and the relief valve monitors the circuit pressure in real time.

[0038] S32: The pull-wire displacement sensor continuously collects the cylinder retraction displacement data, and the pressure sensor synchronously collects the pressure data of the high-pressure hydraulic hose; the control system records the displacement, speed and pressure parameters at each time point in real time, forming a complete data acquisition chain;

[0039] S33: When the tested hydraulic cylinder retracts to the preset buffer section range, the control system automatically increases the sampling frequency, fully records the dynamic change curve of the speed dropping from the stable value to zero, and synchronously collects the buffer section pressure change data;

[0040] S4: Experiment Termination and Data Processing Phase

[0041] S41: When the hydraulic cylinder under test retracts to the end of its stroke, the limit buffer is triggered, and the control system controls the directional valve to cut off the hydraulic circuit and automatically relieve pressure, thus safely terminating the experiment. If an abnormality occurs during the experiment, the experiment will be terminated and restarted after the fault is investigated.

[0042] S42: The control system generates three dynamic curves: displacement / time, velocity / time, and pressure / time. It marks key data points in the buffer section and automatically calculates the buffer performance index using the velocity decay rate = (steady velocity - final velocity) / steady velocity × 100%.

[0043] S43: Evaluate the cylinder convergence performance based on dynamic curves and quantitative indicators.

[0044] This invention provides an operating method for the aforementioned hydraulic cylinder convergence test device. By standardizing and systematizing the operation of the innovative throttling control, real-time monitoring, loading, and fixing structure, it addresses the shortcomings and deficiencies of existing technologies in terms of speed control accuracy, real-time monitoring, versatility, and safety, thereby improving detection accuracy, experimental efficiency, data integrity, and safety assurance.

[0045] Preferably, the key data points of the buffer section include: maximum speed, speed decay inflection point, buffer end displacement and pressure peak value; the preset buffer section range is 2-5mm before the end of the stroke; the target retraction speed control adjustment range is 2-10mm / min.

[0046] Preferably, the coaxiality error between the axis of the hydraulic cylinder being tested and the center line of the frame system is ≤0.2mm; the tension of the displacement sensor's cable is in the range of 5-8N; and the speed fluctuation warning threshold is ±5% and the pressure change warning threshold is ±10%.

[0047] (III) Beneficial Effects

[0048] The present invention provides a hydraulic cylinder convergence test device and its operating method, which has the following beneficial effects:

[0049] 1. Improved detection accuracy: By controlling the speed through the throttle connector, the fluctuation range of the cylinder retraction speed can be controlled within ±5%, which is more than 60% higher than the ±15% fluctuation range of the existing method; the displacement measurement accuracy of the pull wire sensor can reach ±0.1mm, and the instantaneous speed measurement error is less than 0.01m / s, which can accurately capture the speed change in the buffer section.

[0050] 2. Optimized experimental efficiency: The assembly and debugging time of the experimental device is shortened to less than 30 minutes (the existing method requires 1-2 hours), and different specifications of hydraulic cylinders can be adapted by changing the throttling connector, without the need to replace the entire set of experimental equipment, reducing experimental costs by 40%-50%.

[0051] 3. Enhanced data integrity: It can generate displacement / time and velocity / time curves in real time, and record the entire process data of cylinder convergence. In particular, it can quantify the performance indicators of the buffer section, providing data support for the optimization of cylinder buffer structure (such as buffer chamber design and one-way valve parameter adjustment).

[0052] 4. Safety Guarantee: The stable external loading structure and controllable retraction speed can avoid equipment damage caused by cylinder "stirring" or sudden pressure changes, reducing the safety risk during the experiment by more than 90%. Attached Figure Description

[0053] Figure 1 This is a schematic diagram of the hydraulic cylinder convergence test device of the present invention;

[0054] Explanation of reference numerals in the attached figures:

[0055] A: Hydraulic cylinder under test; 1: Longitudinal beam; 2: First end crossbeam; 3: Bottom end crossbeam; 4: External loading device; 5: First end crossbeam mounting device; 6: Bottom end crossbeam mounting device; 7: Hydraulic cylinder mounting base; 8: Cylinder rod mounting base; 9: Throttling connector; 10: Hydraulic pump; 11: Hydraulic oil tank; 12: External loading hydraulic cylinder; 13: Displacement sensor; 14: Video sensor; 15: Control system; 16: Guide rail; 17: Pin hole; 18: Mounting frame. Detailed Implementation

[0056] To better explain and facilitate understanding of the present invention, a detailed description of the invention is provided below with reference to the accompanying drawings and specific embodiments. In this document, directional terms such as "up," "down," "left," and "right" are used interchangeably. Figure 1 The orientation is for reference. To better understand the above technical solution, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings.

[0057] The present invention provides a hydraulic cylinder convergence test device, which includes: a frame system, a fixing system, a hydraulic system, a sensor system, and a control system;

[0058] The frame system is integrally formed from high-strength alloy steel and is detachably connected. It has a horizontal gantry shape and includes: longitudinal beams, a first end crossbeam, a bottom end crossbeam, an external loading device, a first end crossbeam mounting device, and a bottom end crossbeam mounting device. One end of the longitudinal beam is located on the left and right sides of the bottom end crossbeam, and the other end of the longitudinal beam is movably connected to the first end crossbeam. The first end crossbeam mounting device and the bottom end crossbeam mounting device are arranged opposite each other and are detachably connected to the first end crossbeam and the bottom end crossbeam, respectively. The external loading device is connected to the bottom end crossbeam and drives it to move along the longitudinal beam.

[0059] The fixing system includes: a hydraulic cylinder fixing seat, a cylinder rod fixing seat, and a limiting buffer. The hydraulic cylinder fixing seat is connected to the bottom crossbeam mounting device. The hydraulic cylinder fixing seat is equipped with an adjustable mounting frame to adapt to the fixing requirements of cylinders with different diameters. The cylinder rod fixing seat is connected to the front crossbeam mounting device and has an anti-slip bushing inside to adapt to the fixing requirements of hydraulic rods with different diameters. The limiting buffer is fixed at the hydraulic cylinder fixing seat at the retracted end position of the hydraulic cylinder under test to prevent excessive retraction of the cylinder and damage to the components due to collision.

[0060] The hydraulic system includes: a throttle joint, a hydraulic pump, high-pressure hydraulic pipelines, a hydraulic oil tank, an externally loaded hydraulic cylinder, and a directional valve. The throttle joint is detachably connected to the hydraulic oil inlet and outlet of the hydraulic cylinder under test. The throttle joint is connected to the directional valve via high-pressure hydraulic pipelines. The directional valve is connected to the hydraulic pump and the hydraulic oil tank via high-pressure hydraulic pipelines. The hydraulic oil inlet and outlet of the externally loaded hydraulic cylinder are connected to the hydraulic pump via the high-pressure hydraulic pipelines.

[0061] The sensor system includes a displacement sensor, a video sensor, and a pressure sensor. The displacement sensor is installed on the longitudinal beam to measure its relative displacement with respect to the bottom crossbeam. The pressure sensor is installed at the hydraulic oil inlet and outlet of the hydraulic cylinder under test and the externally loaded hydraulic cylinder. The video sensor is installed on the bottom crossbeam to monitor the position of the hydraulic cylinder under test in real time.

[0062] The control system is electrically connected to the sensor system and the hydraulic system, realizing integrated control of speed regulation, data acquisition, curve generation and safety warning.

[0063] An operating method for the aforementioned hydraulic cylinder convergence experimental device includes: an experimental preparation and debugging stage, a parameter preset and system startup stage, an experimental operation and data acquisition stage, and an experimental termination and data processing stage.

[0064] The experimental preparation and debugging phase includes:

[0065] 1. Adjust the spacing between the longitudinal beams of the frame system and the position of the first end crossbeam according to the cylinder diameter and stroke of the hydraulic cylinder being tested. Fix the positions of the first end crossbeam and longitudinal beams with pins.

[0066] 2. Place the cylinder body of the hydraulic cylinder to be tested on the lower mounting frame, adjust the upper mounting frame to fix the cylinder body, and fix the cylinder rod of the hydraulic cylinder to be tested in the cylinder rod end fixing seat of the first end crossbeam to ensure that the axis of the hydraulic cylinder to be tested coincides with the center line of the frame system.

[0067] 3. Select throttle connectors with corresponding orifice diameters and install them at the hydraulic oil inlet and outlet of the hydraulic cylinder respectively. The throttle connectors are connected to the directional valve through high-pressure hydraulic pipelines, and the directional valves are connected to the hydraulic pump and hydraulic oil tank through high-pressure hydraulic pipelines.

[0068] 4. Install the wire-type displacement sensor on the longitudinal beam, fix the wire end to the bottom crossbeam, and perform zero-point calibration to ensure the calibration accuracy reaches ±0.1mm;

[0069] 5. Start the hydraulic pump and run it under no-load, preset the loading pressure and target retraction speed, adjust the relief valve to the corresponding pressure threshold, and complete the hydraulic system debugging;

[0070] Parameter preset and system startup phase

[0071] 6. Input experimental parameters and set safety protection thresholds in the human-computer interaction module, and save them to the PLC controller;

[0072] 7. Start the hydraulic system to ensure that the loading force is applied evenly to the cylinder piston rod; the control system adjusts the opening of the throttle connector through the PLC controller to perform a pre-retraction test on the hydraulic cylinder under test. If the speed fluctuation exceeds the preset threshold, finely adjust the opening of the throttle connector.

[0073] 8. Activate the safety early warning module of the control system to ensure timely response in case of abnormal situations during the experiment;

[0074] Experimental run and data acquisition phase:

[0075] 9. The reversing valve quickly switches to the retraction position, and the hydraulic oil is precisely controlled by the throttle joint to drive the tested hydraulic cylinder to retract at a uniform speed; the external loading force device maintains a stable loading pressure, and the relief valve monitors the circuit pressure in real time.

[0076] 10. A pull-wire displacement sensor continuously collects displacement data of the hydraulic cylinder retraction, while a pressure sensor synchronously collects pressure data of the high-pressure hydraulic hose; the control system records displacement, velocity, and pressure parameters at each time point in real time, forming a complete data acquisition chain.

[0077] 11. When the hydraulic cylinder under test retracts to the preset buffer zone range, the control system automatically increases the sampling frequency, fully records the dynamic change curve of the speed dropping from the stable value to zero, and synchronously collects the pressure change data of the buffer zone;

[0078] Experiment termination and data processing phase

[0079] 12. When the hydraulic cylinder under test retracts to the end of its stroke, the limit buffer is triggered, and the control system controls the directional valve to cut off the hydraulic circuit and automatically relieve pressure, thus safely terminating the experiment. If any abnormality occurs during the experiment, the experiment will be terminated and restarted after the fault has been identified and the problem has been resolved.

[0080] 13. The control system generates three dynamic curves: displacement / time, velocity / time, and pressure / time. Key data points of the buffer section are marked, and the buffer performance index is automatically calculated using the velocity decay rate = (steady velocity - final velocity) / steady velocity × 100%.

[0081] 14. Evaluate the hydraulic cylinder convergence performance based on dynamic curves and quantitative indicators.

[0082] This invention provides a hydraulic cylinder convergence test device and its operating method. By utilizing innovative throttling control, real-time monitoring, loading and fixing structures and their operating methods, it overcomes the shortcomings and deficiencies of existing technologies in terms of speed control accuracy, real-time monitoring, versatility and safety, thereby improving detection accuracy, experimental efficiency, data integrity and safety assurance.

[0083] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention can be understood more clearly and thoroughly, and that the scope of the present invention can be fully conveyed to those skilled in the art.

[0084] Example 1: As Figure 1 As shown, a hydraulic cylinder convergence test device includes: a frame system, a fixing system, a hydraulic system, a sensor system, and a control system;

[0085] The frame system is made of high-strength alloy steel in one piece and can be detachably connected. The overall shape is a horizontal gantry type, including: longitudinal beam 1, first end crossbeam 2, bottom end crossbeam 3, external loading device 4, first end crossbeam mounting device 5, and bottom end crossbeam mounting device 6. One end of the longitudinal beam 1 is set on the left and right sides of the bottom end crossbeam 3, and the other end of the longitudinal beam 1 is movably connected to the first end crossbeam 2. The first end crossbeam mounting device 5 and the bottom end crossbeam mounting device 6 are set opposite to each other and are detachably connected to the first end crossbeam 2 and the bottom end crossbeam 3, respectively. The external loading device 4 is connected to the bottom end crossbeam 3 and drives it to move along the longitudinal beam 1.

[0086] The fixing system includes: a hydraulic cylinder fixing seat 7, a cylinder rod fixing seat 8, and a limiting buffer. The hydraulic cylinder fixing seat 7 is connected to the bottom crossbeam mounting device 6. The hydraulic cylinder fixing seat is equipped with an adjustable mounting frame to adapt to the fixing requirements of cylinders with different diameters. The cylinder rod fixing seat 8 is connected to the front crossbeam mounting device 5 and is equipped with an anti-slip bushing inside to adapt to the fixing requirements of hydraulic rods with different diameters. The limiting buffer is fixed to the hydraulic cylinder fixing seat 7 at the end point of the retraction of the hydraulic cylinder under test to prevent the cylinder from retracting too much and causing collision damage to the components.

[0087] The hydraulic system includes: a throttle connector 9, a hydraulic pump 10, high-pressure hydraulic pipelines, a hydraulic oil tank 11, an externally loaded hydraulic cylinder 12, and a directional valve. The throttle connector 9 is detachably connected to the hydraulic oil inlet and outlet of the hydraulic cylinder A under test. The throttle connector 9 is connected to the directional valve through high-pressure hydraulic pipelines. The directional valve is connected to the hydraulic pump 10 and the hydraulic oil tank 11 through high-pressure hydraulic pipelines. The hydraulic oil inlet and outlet of the externally loaded hydraulic cylinder 12 are connected to the hydraulic pump 10 through high-pressure hydraulic pipelines.

[0088] The sensor system includes: displacement sensor 13, video sensor 14 and pressure sensor. Displacement sensor 13 is installed on the longitudinal beam 1 to measure its relative displacement with the bottom crossbeam 3. Pressure sensor is installed at the hydraulic oil inlet and outlet of the hydraulic cylinder A under test and the external loading force hydraulic cylinder 12. Video sensor 14 is installed on the bottom crossbeam 3 to monitor the position of the hydraulic cylinder A under test in real time.

[0089] The control system 15 is electrically connected to the sensor system and hydraulic system to achieve integrated control of speed regulation, data acquisition, curve generation and safety warning.

[0090] The control system includes a PLC controller, a human-machine interface module, and a data acquisition module. The PLC controller is electrically connected to the human-machine interface module, the data acquisition module, the hydraulic pump, and the directional valve. The data acquisition module is electrically connected to the sensor system. The operator operates the human-machine interface module.

[0091] The longitudinal beam 1 is provided with a slide rail 16, and the first end crossbeam 2 and the bottom end crossbeam 3 can slide on the slide rail 16; the longitudinal beam 1 is provided with a pin hole 17, and the first end crossbeam 2 is provided with a corresponding pin hole, and the relative position of the first end crossbeam 2 and the longitudinal beam 1 is fixed by the pin shaft.

[0092] The external loading force device 4 is driven by the external loading force hydraulic cylinder 12 to drive the bottom crossbeam 3, and the stroke of the bottom crossbeam 3 is 500-3000mm; the limiting buffer adopts a combination structure of elastic buffer block and rigid limiting plate; the diameter of the throttling orifice of the throttling connector 9 is 0.5-5mm, which can be quickly replaced according to the flow requirements of different tested hydraulic cylinders A.

[0093] The hydraulic system also includes a relief valve, which is located at the hydraulic oil inlet and outlet of the hydraulic cylinder A under test and the externally loaded hydraulic cylinder 12, respectively, where the pressure sensor is located.

[0094] The displacement sensor 13 is a pull-wire type displacement sensor. The displacement sensor 13, video sensor 14 and pressure sensor transmit measurement data to the data acquisition module in real time via wires or wirelessly.

[0095] The mounting frame 18 of the hydraulic cylinder mounting base 7 has two parts, upper and lower. The lower mounting frame 18 is fixed to one end of the hydraulic cylinder mounting base 7, and the upper mounting frame 18 moves up and down in the vertical direction under the drive of the hydraulic cylinder. It is equipped with anti-slip bushings inside to adapt to the fixing requirements of hydraulic cylinders with different cylinder diameters.

[0096] Example 2: Figure 1As shown, an operating method for the aforementioned hydraulic cylinder convergence experimental device includes: an experimental preparation and debugging stage, a parameter preset and system startup stage, an experimental operation and data acquisition stage, an experimental termination and data processing stage, and an experimental cleanup and equipment reset stage. Specific steps include:

[0097] The experimental preparation and debugging phase includes:

[0098] 1. Based on the cylinder diameter and stroke of the hydraulic cylinder A being tested, adjust the spacing between the longitudinal beams 1 of the frame system, adjust the position of the first end crossbeam 2, and fix the position of the first end crossbeam 2 and the longitudinal beam 1 with a high-strength pin.

[0099] 2. Adjust the position of the hydraulic cylinder fixing seat 7 on the bottom crossbeam 2, place the cylinder body of the hydraulic cylinder A to be tested on the lower mounting frame 18, adjust the upper mounting frame 18 to fix the cylinder body of the hydraulic cylinder A to be tested, and fix the cylinder rod of the hydraulic cylinder A to be tested in the cylinder rod end fixing seat 8 of the first crossbeam 2 to ensure that the hydraulic cylinder axis coincides with the center line of the frame system and the coaxiality error is ≤0.2mm;

[0100] 3. Based on the rated flow rate and predetermined target of the hydraulic cylinder A under test, select the corresponding orifice diameter throttle connector 9 through fluid dynamics calculations, and install it on the hydraulic oil inlet and outlet of the hydraulic cylinder under test respectively. The throttle connector 9 is connected to the reversing valve through high-pressure hydraulic pipelines. The reversing valve is connected to the hydraulic pump 10 and the hydraulic oil tank 11 through high-pressure hydraulic pipelines. Check the sealing of the hydraulic circuit to ensure that there is no leakage.

[0101] 4. Fix the pull wire end of the pull wire displacement sensor 13 to the bottom crossbeam 3. Install the sensor on the longitudinal beam 1, so that the tension of the pull wire is in the range of 5-8N. Perform zero-point calibration and accuracy calibration on the sensor through the built-in calibration program of the control system to ensure that the calibration accuracy reaches ±0.1mm. Start the data transmission test to confirm that there is no packet loss or delay in data transmission, and ensure the reliability of data acquisition.

[0102] 5. Fill the hydraulic oil tank 11 with standard hydraulic oil until the oil level reaches 80%-90% of the rated capacity of the tank. Start the oil temperature control module and adjust the oil temperature to the range of 35-40℃. Start the hydraulic pump 10 and run it unloaded for 5 minutes. Check that there are no leaks in the high-pressure hydraulic pipelines, joints and seals. Set the loading pressure and target retraction speed through the touch screen, and adjust the relief valve to the corresponding pressure threshold to complete the hydraulic system debugging.

[0103] Parameter preset and system startup phase

[0104] 6. Input experimental parameters through the human-machine interaction module, including the model of the hydraulic cylinder to be tested, cylinder diameter, stroke, target retraction speed, loading pressure, and buffer section monitoring range. Set safety protection thresholds, setting the speed fluctuation warning threshold to ±5% and the pressure sudden change warning threshold to ±10%. After setting the parameters, save them to the PLC controller.

[0105] 7. Start the hydraulic system and supply hydraulic oil to the throttle joint, hydraulic pump 10, and high-pressure hydraulic pipeline at the preset pressure. Stabilize the loading pressure through the relief valve to ensure that the loading force is evenly applied to the piston rod of the cylinder. The loading pressure stabilization time is ≤3s. The control system adjusts the opening of the throttle joint 9 through the PLC controller to perform a pre-retraction test on the hydraulic cylinder A under test. Collect the speed data during the pre-retraction process. If the speed fluctuation exceeds the preset threshold, the operator adjusts the opening of the throttle joint until the speed fluctuation is stabilized within ±5%, thus completing the speed pre-control and ensuring the accuracy of the formal experiment.

[0106] 8. After confirming that the limit buffer is installed in place, the hydraulic system is leak-free, and the sensor data transmission is normal, activate the safety warning module of the control system and start the audible and visual alarm device to put the system in a safe standby state, so as to ensure that it can respond in time when abnormal situations occur during the experiment and avoid equipment damage or safety accidents caused by cylinder movement and sudden pressure changes.

[0107] Experimental run and data acquisition phase:

[0108] 9. The control system issues a retraction command, the reversing valve quickly switches to the retraction position, the hydraulic oil enters the rodless chamber of the cylinder after the flow rate is precisely controlled by the throttle connector 9, and drives the cylinder to retract at a uniform speed; the external loading force device 4 maintains a stable loading pressure, the overflow valve monitors the circuit pressure in real time, and timely removes abnormal pressure to avoid pressure fluctuations affecting the experimental accuracy.

[0109] 10. The pull-wire displacement sensor 13 continuously collects cylinder retraction displacement data at a sampling frequency of 100Hz, and the pressure sensor synchronously collects pressure data from the high-pressure hydraulic hose. The collected raw data is transmitted to the control system 15 in real time. The control system 15 converts the displacement data into instantaneous velocity data through a built-in algorithm with a measurement error of less than 0.01m / s. It records the displacement, velocity, and pressure parameters at each time point in real time, forming a complete data acquisition chain.

[0110] 11. When the tested hydraulic cylinder A retracts to the preset buffer section range, the control system 15 automatically increases the sampling frequency to 200Hz, accurately captures the speed decay process of the buffer section, fully records the dynamic change curve of the speed from the stable value to zero, and synchronously collects the pressure change data of the buffer section, quantifies key performance indicators such as buffer time, speed decay rate, and pressure peak, and provides core data for convergence evaluation.

[0111] Experiment termination and data processing phase

[0112] 12. When the cylinder rod of the hydraulic cylinder A under test retracts to the end of its stroke, the limit buffer triggers the position switch. After receiving the position signal, the control system 15 immediately outputs a control command to control the directional valve to cut off the hydraulic circuit, stop the hydraulic pump 10 from supplying oil, and start the relief valve to automatically depressurize, so that the hydraulic cylinder A under test remains stationary and the experiment is safely terminated. If abnormal speed or pressure occurs during the experiment, the safety warning module is immediately activated to forcibly terminate the experiment and depressurize. The experiment can be restarted after the fault is investigated, ensuring the safety of the experiment process and the reliability of the data.

[0113] 13. The control system's data processing software automatically organizes and collects data from the entire process, removes abnormal data points, generates three dynamic curves: displacement / time, velocity / time, and pressure / time, marks key data points in the buffer section, and automatically calculates buffer performance indicators using the formula: velocity decay rate = (stable velocity - final velocity) / stable velocity × 100%.

[0114] 14. Based on dynamic curves and quantitative indicators, evaluate whether the hydraulic cylinder buffer performance meets the design standards, and provide accurate data support for the optimization of the hydraulic cylinder buffer chamber structure, adjustment of one-way valve parameters, and improvement of product quality;

[0115] Experimental cleaning and apparatus reset stage

[0116] 15. Turn off the hydraulic pump 10. After the hydraulic circuit is completely depressurized (pressure drops to 0MPa), disconnect the connecting flange between the cylinder and the loading end, and remove the hydraulic cylinder A under test; remove the throttle connector 9, and clean the quick connector, pipe interface and throttle connector 9 to remove oil residue and impurities.

[0117] 16. Return the cylinder mounting base 8 and the sensor to their initial positions, and straighten the high-pressure hydraulic pipeline to avoid bending or wear; turn off the power to the control system, and perform a visual inspection and record the status of the experimental device.

[0118] Key data points for the buffer section include: maximum speed, speed decay inflection point, buffer end displacement, and pressure peak; the preset buffer section range is 2-5mm before the end of the stroke; the target retraction speed control adjustment range is 2-10mm / min.

[0119] The coaxiality error between the axis of the tested hydraulic cylinder A and the center line of the frame system is ≤0.2mm; the tension of the pull wire of the pull wire displacement sensor 13 is in the range of 5-8N; the speed fluctuation warning threshold is ±5% and the pressure change warning threshold is ±10%.

[0120] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0121] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0122] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "over," or "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," or "beneath" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0123] In the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0124] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A hydraulic cylinder convergence test device, characterized by The application relates to a test system for a hydraulic cylinder. The test system comprises a frame system, a fixing system, a hydraulic system, a sensor system and a control system. The frame system is detachably connected and comprises longitudinal beams, a first-end cross beam, a bottom-end cross beam, an external loading device, a first-end cross beam mounting device and a bottom-end cross beam mounting device. The longitudinal beams are arranged at the left and right sides of the bottom-end cross beam, and the other ends of the longitudinal beams are movably arranged on the first-end cross beam. The first-end cross beam mounting device and the bottom-end cross beam mounting device are oppositely arranged and detachably connected with the first-end cross beam and the bottom-end cross beam respectively. The external loading device is connected with the bottom-end cross beam and drives the bottom-end cross beam to move along the longitudinal beams. The fixing system comprises a hydraulic cylinder fixing seat, a cylinder rod fixing seat and a limiting buffer.

2. The hydraulic cylinder convergence test apparatus according to claim 1, characterized by: The hydraulic cylinder fixing seat is connected with the bottom-end cross beam mounting device and is provided with an adjustable mounting frame to adapt to the fixing requirements of hydraulic cylinders with different diameters.

3. The hydraulic cylinder convergence test apparatus according to claim 2, characterized by: The cylinder rod fixing seat is connected with the first-end cross beam mounting device and is internally provided with an anti-skid bushing to adapt to the fixing requirements of hydraulic rods with different diameters.

4. The hydraulic cylinder convergence test apparatus according to claim 3, characterized by: The limiting buffer is fixedly arranged on the hydraulic cylinder fixing seat at the retraction end position of the tested hydraulic cylinder to avoid component collision and damage caused by excessive retraction of the hydraulic cylinder.

5. The hydraulic cylinder convergence test apparatus according to claim 4, characterized by: The hydraulic system comprises a throttle joint, a hydraulic pump, a high-pressure hydraulic pipeline, a hydraulic oil tank, an external loading force hydraulic cylinder and a reversing valve.

6. The hydraulic cylinder convergence test apparatus according to claim 5, wherein: The throttle joint is detachably connected with the hydraulic oil inlet and outlet of the tested hydraulic cylinder and is connected with the reversing valve through the high-pressure hydraulic pipeline. The reversing valve is connected with the hydraulic pump and the hydraulic oil tank through the high-pressure hydraulic pipeline. The external loading force hydraulic cylinder is connected with the hydraulic pump through the high-pressure hydraulic pipeline. The sensor system comprises a displacement sensor, a video sensor and a pressure sensor. The displacement sensor is arranged on the longitudinal beam to measure the relative displacement of the bottom-end cross beam. The pressure sensor is arranged on the hydraulic oil inlet and outlet of the tested hydraulic cylinder and the external loading force hydraulic cylinder. The video sensor is arranged on the bottom-end cross beam. The control system is electrically connected with the sensor system and the hydraulic system. The control system comprises a PLC controller, a man-machine interaction module and a data acquisition module. The PLC controller is electrically connected with the man-machine interaction module, the data acquisition module, the hydraulic pump and the reversing valve. The data acquisition module is electrically connected with the sensor system. An operator operates the man-machine interaction module. The longitudinal beam is provided with a sliding rail, and the first-end cross beam and the bottom-end cross beam can slide on the sliding rail. The longitudinal beam is provided with a pin hole, and the first-end cross beam is provided with a corresponding pin hole. The relative position of the first-end cross beam and the longitudinal beam is fixed by using a pin shaft. The external loading device drives the bottom-end cross beam by the external loading force hydraulic cylinder. The stroke of the bottom-end cross beam is 500-3000 mm. The limiting buffer adopts a combined structure of an elastic buffer block and a rigid limiting plate. The aperture of the throttle hole of the throttle joint is 0.5-5 mm, and the throttle joint can be quickly replaced according to the flow requirements of different tested hydraulic cylinders. The hydraulic system further comprises an overflow valve. The overflow valve is arranged on the hydraulic oil inlet and outlet of the tested hydraulic cylinder and the external loading force hydraulic cylinder. The displacement sensor is a pull-wire displacement sensor. The displacement sensor, the video sensor and the pressure sensor adopt wire or wireless real-time transmission to transmit measurement data to the data acquisition module.

7. The hydraulic cylinder convergence test apparatus according to claim 6, characterized by: The mounting frame of the hydraulic cylinder fixing base has upper and lower parts, the lower part mounting frame is fixed at one end of the hydraulic cylinder fixing base, the upper part mounting frame moves up and down along the vertical direction under the drive of the hydraulic cylinder, and an anti-skid bushing is arranged in the upper part mounting frame, so that the fixing requirement of the hydraulic cylinder with different cylinder diameters is met.

8. An operating method of the hydraulic cylinder convergence experiment device, using the hydraulic cylinder convergence experiment device according to claims 1-7, comprising the following steps: S1: experimental preparation and debugging stage: S01: adjust the distance between the longitudinal beams of the frame system according to the cylinder diameter and stroke of the tested hydraulic cylinder, adjust the position of the first end cross beam, and fix the position of the first end cross beam and the longitudinal beam through the pin shaft; S02: place the cylinder body of the tested hydraulic cylinder on the lower part mounting frame, adjust the cylinder body fixing of the upper part mounting frame, fix the cylinder rod of the tested hydraulic cylinder in the cylinder rod end fixing base of the first end cross beam, and ensure that the axis of the tested hydraulic cylinder coincides with the center line of the frame system; S03: select the throttle joint corresponding to the hole diameter, and respectively install the throttle joint in the hydraulic oil inlet and outlet of the hydraulic cylinder, the throttle joint is connected with the reversing valve through the high-pressure hydraulic pipeline, the reversing valve is connected with the hydraulic pump and the hydraulic oil tank through the high-pressure hydraulic pipeline; S04: install the wire displacement sensor on the longitudinal beam, fix the wire end of the wire displacement sensor to the bottom cross beam, and perform zero point calibration to ensure that the calibration accuracy is ±0.1 mm; S05: start the hydraulic pump and run under no load, preset the loading pressure and target retraction speed, adjust the overflow valve to the corresponding pressure threshold, and complete the hydraulic system debugging; S2: parameter presetting and system starting stage: S21: input the experimental parameters through the man-machine interaction module, set the safety protection threshold, and save to the PLC controller; S22: start the hydraulic system to ensure that the loading force uniformly acts on the oil cylinder piston rod; the control system adjusts the opening of the throttle joint through the PLC controller to test the pre-retraction of the tested hydraulic cylinder, and adjusts the opening of the throttle joint if the speed fluctuation exceeds the preset threshold; S23: activate the control system safety warning module to ensure that the system can respond in time when an abnormal condition occurs during the experiment; S3: experimental operation and data acquisition stage: S31: the reversing valve is quickly switched to the retraction station, the hydraulic oil is accurately controlled to drive the tested hydraulic cylinder to retract at a constant speed through the throttle joint; the external loading device maintains stable loading pressure, and the overflow valve monitors the loop pressure in real time; S32: the wire displacement sensor continuously collects the retraction displacement data of the oil cylinder, and the pressure sensor synchronously collects the pressure data of the high-pressure hydraulic hose; the control system records the displacement, speed and pressure parameters at each time node in real time to form a complete data acquisition chain; S33: when the tested hydraulic cylinder retracts to the preset buffer segment range, the control system automatically increases the sampling frequency to record the dynamic change curve of the speed from the stable value to zero, and synchronously collects the pressure change data in the buffer segment; S4: experimental termination and data processing stage S41: when the tested hydraulic cylinder retracts to the stroke end point, the limit buffer is triggered, the control system controls the reversing valve to cut off the hydraulic circuit to automatically release pressure, and the experiment is safely terminated; If an abnormality occurs during the experiment, the experiment is terminated, and the experiment is restarted after the fault is checked. S42: The control system generates displacement / time, speed / time, and pressure / time dynamic curves, labels key data points of the buffer section, and automatically calculates buffer performance indicators using a speed attenuation rate=(steady speed-end point speed) / steady speed*100%; S43: Based on the dynamic curves and quantitative indicators, the oil cylinder convergence performance is evaluated.

9. The method of operating a hydraulic cylinder convergence test apparatus of claim 8, wherein: The key data points of the buffer section include maximum speed, speed attenuation inflection point, buffer end point displacement, and pressure peak value; the preset buffer section range is 2-5 mm before the end of the stroke; and the target retraction speed control adjustment range is 2-10 mm / min.

10. The method of operating a hydraulic cylinder convergence test apparatus of claim 9, wherein: The detected hydraulic oil cylinder axis is coaxial with the frame system centerline with an error of ≤0.2 mm; the displacement sensor's wire tension is in the range of 5-8 N; the speed fluctuation early warning threshold is ±5%, and the pressure sudden change early warning threshold is ±10%.

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