Integrated hydraulic cylinder test bench

Abstract

The application discloses an integrated hydraulic cylinder test test-bed, which comprises a test unit, an oil supply unit, an auxiliary unit and an electric control unit, wherein the test unit is connected with the oil supply unit and the auxiliary unit respectively, the test unit, the oil supply unit and the auxiliary unit are connected with the electric control unit respectively, the oil supply unit provides the required pressure for the test of the test unit, the test unit is used for testing the oil pressure of the hydraulic cylinder and transmitting the pressure change signal in the hydraulic cylinder to the electric control unit, the electric control unit is used for controlling the electromagnetic valve to change the oil flow direction in the pipeline of the test-bed, and the auxiliary unit is used for injecting high-pressure gas into the pipeline after the test is completed and discharging the oil back to the oil tank. The application has the advantages that the oil is discharged based on the gas source, the full-automatic continuous test of the hydraulic cylinder is realized, and the test efficiency of the hydraulic cylinder is improved.

Description

Technical Field

[0001] This invention relates to the fields of wind turbine blade transportation and high-flow hydraulic technology, and more specifically, to an integrated hydraulic cylinder testing bench. Background Technology

[0002] Currently, high-flow hydraulic cylinders are core actuators in hydraulic suspension systems, and their performance directly affects the overall system's performance. In particular, designing a hydraulic cylinder test bench is crucial for ensuring the quality of hydraulic cylinders in the hydraulic suspension system of wind power transport vehicles. A hydraulic cylinder test bench is a device specifically designed to test the performance of hydraulic cylinders. According to GB / T15622-2005 "Test Methods for Hydraulic Cylinders," the test items and methods for hydraulic cylinder product performance should be able to comprehensively test key performance indicators such as starting pressure, pressure resistance, durability, and leakage. Therefore, testing with a hydraulic cylinder test bench prevents hydraulic cylinders with quality problems from entering the market, thus avoiding safety hazards and economic losses. A highly automated hydraulic cylinder test bench can reduce manual operation, improve testing efficiency, and reduce human error.

[0003] Existing hydraulic cylinder testing benches have several shortcomings, including low automation, limited test items, low accuracy, and inability to test multiple types of hydraulic cylinders, resulting in low testing efficiency and inaccurate test results. In particular, traditional testing benches are time-consuming and prone to errors due to manual adjustment of test parameters and lack of sensor detection, making it difficult to achieve high-precision control and data acquisition.

[0004] In summary, at least one of the following technical problems exists:

[0005] It suffers from low automation, limited testing items, low accuracy, and inability to simultaneously test multiple types and several hydraulic cylinders.

[0006] Low testing efficiency and inaccurate test results;

[0007] Manually adjusting test parameters and lacking sensor detection are time-consuming and prone to errors, making it difficult to achieve high-precision control and data acquisition.

[0008] Low efficiency in oil drainage and return, incomplete oil drainage, and low efficiency in continuous testing;

[0009] It is difficult to efficiently simulate the complete oil flow state test from the oil tank to the hydraulic cylinder. Summary of the Invention

[0010] The main objective of this invention is to provide an integrated hydraulic cylinder testing bench to address at least one of the following technical problems in existing technologies: low automation, limited testing items, low accuracy, inability to test multiple types of hydraulic cylinders; low testing efficiency and inaccurate test results; manual adjustment of test parameters and lack of sensor detection, which is time-consuming and prone to misoperation, making it difficult to achieve high-precision control and data acquisition; low oil discharge and return efficiency, incomplete oil discharge, and low continuous testing efficiency; and difficulty in efficiently simulating the complete oil flow state from the oil tank to the hydraulic cylinder.

[0011] To achieve the above objectives, according to one aspect of the present invention, an integrated hydraulic cylinder testing bench is provided, comprising a testing unit, an oil supply unit, an auxiliary unit, and an electronic control unit. The testing unit is connected to the oil supply unit and the auxiliary unit, respectively. The testing unit, the oil supply unit, and the auxiliary unit are all connected to the electronic control unit. The oil supply unit provides the testing unit with the pressure required for testing. The testing unit is used to test the hydraulic cylinder oil pressure and transmit the pressure change signal inside the hydraulic cylinder to the electronic control unit. The electronic control unit is used to control the solenoid valve to reverse and change the flow direction of the oil in the testing bench pipeline. The auxiliary unit is used to inject high-pressure gas into the pipeline after the test and discharge the oil back to the oil tank.

[0012] Preferably, the oil supply unit includes a motor, which is connected to a hydraulic pump via a coupling. The hydraulic pump is connected to a suction oil filter, which is connected to an oil tank. The hydraulic pump is connected to a second three-position four-way solenoid valve of the electronic control unit via a second check valve. The second three-position four-way solenoid valve is connected to a flow meter, which is connected to a return oil filter. The return oil filter is connected to an oil tank. An overflow valve is connected between the second check valve and the second three-position four-way solenoid valve.

[0013] Preferably, the auxiliary unit includes an air source connected to a pneumatic triplet, which is connected to a first one-way valve. The first one-way valve is connected to a three-position five-way solenoid directional valve of the electronic control unit. A first silencer and a second silencer are connected to the three-position five-way solenoid directional valve. The pneumatic triplet includes an air filter, a pressure reducing valve, and an oil mist lubricator connected in series. The auxiliary unit also includes a temperature sensor, a first swing air motor, a second swing air motor, a first throttle valve, and a second throttle valve. The temperature sensor is located in the oil tank. The first swing air motor, the second swing air motor, the first throttle valve, and the second throttle valve are located in the air path connecting the auxiliary unit and the test unit.

[0014] Preferably, the test unit includes several test branches, each test branch is equipped with a high-pressure ball valve, a quick connector, a pressure gauge, and a pressure sensor. The high-pressure ball valve is connected to the quick connector, and a pressure sensor and a pressure gauge are also provided between the high-pressure ball valve and the quick connector. The quick connector is connected to a corresponding hydraulic cylinder. A corresponding high-pressure ball valve and a swing air motor combination are also provided between the test branch and the air circuit of the auxiliary unit. The swing air motor drives the high-pressure ball valve to rotate, realizing the pneumatic connection or locking of the oil circuit. The test branches are arranged in pairs.

[0015] Preferably, the electronic control unit includes a PLC control system, a first three-position four-way solenoid directional valve, a second three-position four-way solenoid directional valve, and a three-position five-way solenoid directional valve. The pressure sensor of the test unit monitors the pressure change in the hydraulic cylinder and transmits the signal to the PLC control system. The PLC control system controls the first three-position four-way solenoid directional valve, the second three-position four-way solenoid directional valve, and the three-position five-way solenoid directional valve to switch directions, thereby changing the direction of oil flow in the test bench pipeline.

[0016] Preferably, under no-load conditions, the electronic control unit controls the motor speed to be increased slowly, and the system pressure is gradually increased to the minimum starting pressure of the hydraulic cylinder when it starts. By applying a fixed pressure to the inside of the hydraulic cylinder and holding the pressure for a certain period of time, pressure resistance data is obtained. During the test, the pressure sensor monitors the pressure change in real time and feeds it back to the PLC control system of the electronic control unit. If the pressure is lower than the set lower limit or higher than the set upper limit, the PLC control system controls the alarm to be issued and takes corresponding measures.

[0017] Preferably, the electronic control unit controls the oil supply unit to inject hydraulic oil into the hydraulic cylinder to a specified pressure value, and uses a pressure sensor to detect pressure changes over a certain period of time to test whether the piston leaks internally.

[0018] Preferably, when the test ends, the electronic control unit controls the four-way solenoid directional valve to the left position, and the swing air motor rotates in the opposite direction, locking the branch oil circuit connected to the hydraulic cylinder's air chamber and connecting the branch oil circuit connected to the return oil chamber. The electronic control unit controls the air source to pump air into the hydraulic cylinder, pushing the piston to move and draining the oil on the other side of the hydraulic cylinder piston back to the oil tank, completing the oil recovery and preparing for the next round of testing.

[0019] Preferably, the oil is drained back to the oil tank via an air source, and the first and second swing air motors are controlled by the air source, which in turn control the first and second high-pressure ball valves, thus achieving dual air-hydraulic linkage control.

[0020] Preferably, the PLC control system of the electronic control unit automatically records and saves the time-varying pressure curve data in the pipeline. Based on the pressure curve data, the PLC control system realizes the test functions of automatically switching the oil inlet and outlet direction, automatically locking the valve circuit, automatically switching the air circuit to discharge the oil inside the hydraulic cylinder, and automatically judging the sealing performance of the hydraulic cylinder.

[0021] The technical solution of this invention has the following technical effects:

[0022] This system integrates functions to test the reciprocating operation of a hydraulic cylinder and purge internal air. Under no-load conditions, the system pressure is adjusted and gradually increased to the point where the hydraulic cylinder starts, testing its minimum starting pressure. A constant pressure is applied to the hydraulic cylinder and held for a certain time to test its pressure resistance. Hydraulic oil is injected into the cylinder to a specified pressure value, and the system monitors pressure changes over a certain period to test for internal piston leakage. By pressurizing the hydraulic cylinder, leaks are checked at static seals, mating surfaces, and adjustable parts. Low-pressure sealing is tested under conditions with a cylinder diameter greater than 32mm and a minimum pressure below 0.5MPa. The system also tests the stroke by running the hydraulic cylinder to its extreme positions.

[0023] At the end of the test, the three-position five-way solenoid directional valve is controlled by the electronic control unit. The gas output from the air source is processed by the pneumatic triplet (air filter, pressure reducing valve, oil mist lubricator) and then passes through the first check valve to the three-position five-way solenoid directional valve, and is discharged through the first or second silencer. At the same time, the electronic control unit controls the four-way solenoid directional valve to the left position, and the swing air motor rotates in the opposite direction, locking the branch oil circuit connected to the hydraulic cylinder's air chamber and opening the branch oil circuit connected to the return oil chamber. The air source pumps gas into the hydraulic cylinder, pushing the piston to move and draining the oil on the other side of the hydraulic cylinder piston back to the oil tank, completing the oil recovery and preparing for the next round of complete oil circuit flow and pressure test, thus improving test efficiency.

[0024] The operation of draining oil back to the oil tank via an air source completes oil recovery, preparing for the next round of complete oil circuit flow and pressure testing, improving testing efficiency. Furthermore, the air source controls the swing air motor to operate the high-pressure ball valve, achieving automatic control. That is, air source linkage control: the auxiliary unit not only realizes the automatic recovery of oil after the test through the air source, but also controls the swing air motor to control the opening and closing of the high-pressure ball valve, realizing the automatic control of oil circuit connection or lock-up. This forms a dual application of the air source in oil recovery and oil circuit control, simplifying the system structure and improving the reliability of control.

[0025] After the test, the air source injects high-pressure gas into the pipeline to drain the oil back into the oil tank, preparing for the next batch of hydraulic cylinder tests. The swing air motor in the auxiliary unit is powered by the air source. When the air source fills the hydraulic cylinder, it locks the oil supply unit's inlet pipeline, achieving rapid and efficient drainage of the oil in the pipeline and simulating the complete oil flow state from the oil tank to the hydraulic cylinder. Attached Figure Description

[0026] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0027] Figure 1 A schematic diagram of an integrated hydraulic cylinder test bench according to the present invention is shown.

[0028] The above figures include the following reference numerals:

[0029] Air source 1; First silencer 2.1; Second silencer 2.2; Pneumatic triplet 3; 4; Three-position five-way solenoid directional valve 4; First throttle valve 5.1; Second throttle valve 5.2; First high-pressure ball valve 6.1; Second high-pressure ball valve 6.2; Third high-pressure ball valve 6.3; Fourth high-pressure ball valve 6.4; Fifth high-pressure ball valve 6.5; Sixth high-pressure ball valve 6.7; Eighth high-pressure ball valve 6.8; First pressure gauge 7.1; Second pressure gauge 7.2; Third pressure gauge 7.3; Fourth pressure gauge 7.4; Fifth pressure gauge 7.5; Sixth pressure gauge 7.6; Seventh pressure gauge 7.7; First pressure sensor 8.1; Second pressure sensor 8.2; Third pressure sensor 8.3; Fourth pressure sensor 8.4; Fifth pressure sensor 8.5; Sixth pressure sensor 8.6; First quick connector 9.1; Second quick connector 9.2; Third quick connector 9.3; Fourth quick connector 9.4; Fifth quick connector 9.5; Sixth quick connector 9.6; First swing air motor 10.1; Second swing air motor 10.2; First three-position four-way solenoid directional valve 11.1; Second three-position four-way solenoid directional valve 11.2; First check valve 12.1; Second check valve 12.2; Hydraulic pump 13; Coupling 14; Motor 15; Relief valve 16; Suction oil filter 17; Flow meter 18; Return oil filter 19; Temperature sensor 20; Oil tank 21. Detailed Implementation

[0030] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0031] like Figure 1As shown, this embodiment of the invention provides an integrated hydraulic cylinder testing bench, including a testing unit, an oil supply unit, an auxiliary unit, and an electronic control unit. The testing unit is connected to the oil supply unit and the auxiliary unit, respectively. The testing unit, the oil supply unit, and the auxiliary unit are all connected to the electronic control unit. The oil supply unit provides the testing unit with the pressure required for testing. The testing unit is used to test the hydraulic cylinder oil pressure and transmit the pressure change signal inside the hydraulic cylinder to the electronic control unit. The electronic control unit is used to control the solenoid valve to change the direction of oil flow in the pipeline of the testing bench. The auxiliary unit is used to inject high-pressure gas into the pipeline after the test and discharge the oil back to the oil tank 21.

[0032] In this embodiment, the oil supply unit includes a second check valve 12.2, a hydraulic pump 13, a coupling 14, a motor 15, a relief valve 16, an oil suction filter 17, a flow meter 18, a return oil filter 19, a temperature sensor 20, and an oil tank 21. The motor 15 is connected to the hydraulic pump 13 via the coupling 14. The hydraulic pump 13 is connected to the oil suction filter 17, and the oil suction filter 17 is connected to the oil tank 21. The hydraulic pump 13 is connected to the second three-position four-way solenoid directional valve 11.2 of the electronic control unit via the second check valve 12.2. The second three-position four-way solenoid directional valve 11.2 is connected to the flow meter 18, the flow meter 18 is connected to the return oil filter 19, and the return oil filter 19 is connected to the oil tank 21. An relief valve 16 is connected between the second check valve 12.2 and the second three-position four-way solenoid directional valve 11.2. In the specific oil supply unit, motor 15 provides power, driving hydraulic pump 13 through coupling 14, serving as the power source for the oil supply unit. Coupling 14 connects motor 15 and hydraulic pump 13, transmitting power and ensuring their coaxiality for smooth power transmission. Hydraulic pump 13 converts the mechanical energy of motor 15 into hydraulic energy, drawing hydraulic oil from oil tank 21 and pressurizing it for output, providing the required pressure oil to the testing unit. Oil suction filter 17 is installed at the suction port of hydraulic pump 13, filtering the hydraulic oil drawn into oil tank 21 to prevent impurities from entering hydraulic pump 13, protecting the pump body and the entire hydraulic system. Oil tank 21 stores hydraulic oil, providing oil reserves for the hydraulic system, and also serves to dissipate heat and settle impurities. A second check valve 12.2 is installed between hydraulic pump 13 and the second three-position four-way solenoid directional valve 11.2 to prevent backflow of oil, ensuring that oil can only flow from hydraulic pump 13 to the directional valve, protecting hydraulic pump 13. The second three-position four-way solenoid directional valve 11.2 is controlled by the electronic control unit to change the flow direction of the oil, thereby controlling the movement direction of the hydraulic cylinder and realizing the switching of the oil flow direction during the test. The flow meter 18 measures the oil flow rate through the pipeline, providing a basis for system flow control and test data analysis. The return oil filter 19 is installed on the return oil line to filter the oil returning to the oil tank 21, removing impurities and ensuring the cleanliness of the oil in the oil tank 21. The relief valve 16 is connected in parallel on the oil line between the second check valve 12.2 and the second three-position four-way solenoid directional valve 11.2. When the system pressure exceeds the set value, the relief valve 16 opens, and the oil flows back to the oil tank 21, playing a safety protection role and preventing damage to components due to excessive system pressure.

[0033] In this embodiment, the auxiliary unit includes an air source 1, which is connected to a pneumatic triplet 3. The pneumatic triplet 3 is connected to a first one-way valve 12.1, which is connected to a three-position five-way solenoid directional valve 4 of the electronic control unit. A first silencer 2.1 and a second silencer 2.2 are connected to the three-position five-way solenoid directional valve 4. The pneumatic triplet 3 includes an air filter, a pressure reducing valve, and an oil mist lubricator connected in series. The auxiliary unit also includes a temperature sensor 20, a first swing air motor 10.1, a second swing air motor 10.2, a first throttle valve 5.1, and a second throttle valve 5.2. The temperature sensor 20 is located in the oil tank 21. The first swing air motor 10.1, the second swing air motor 10.2, the first throttle valve 5.1, and the second throttle valve 5.2 are located in the air path connecting the auxiliary unit and the test unit. Specifically, in the auxiliary unit, the air source 1 provides high-pressure gas, which is the power source of the auxiliary unit and is used to drain the oil back to the oil tank 21 after the test and to drive the swing air motors. The pneumatic triplet 3 includes an air filter, a pressure reducing valve, and an oil mist lubricator. The air filter filters impurities in the air source 1, ensuring gas cleanliness; the pressure reducing valve reduces the high-pressure gas from the air source 1 to the stable pressure required by the system; the oil mist lubricator injects lubricating oil into the air circuit to lubricate the pneumatic components and extend their service life. A first one-way valve 12.1 is installed between the pneumatic triplet 3 and the three-position five-way solenoid directional valve 4 to prevent gas backflow and ensure that gas can only flow from the pneumatic triplet 3 to the directional valve. The three-position five-way solenoid directional valve 4 is controlled by the electronic control unit to change the gas flow direction, controlling the direction of gas entering the swing air motor, thereby controlling the rotation direction of the swing air motor. At the same time, it discharges excess gas through the connected first silencer 2.1 and second silencer 2.2, reducing noise. The first silencer 2.1 and second silencer 2.2 are installed on the three-position five-way solenoid directional valve 4 to reduce noise during gas discharge and minimize environmental impact. Temperature sensor 20 is installed in oil tank 21 to monitor the temperature of the oil in oil tank 21 in real time, providing data support for system temperature control and fault diagnosis. The first swing air motor 10.1 and the second swing air motor 10.2 are installed in the air circuit connecting the auxiliary unit and the test unit. Driven by air source 1, they rotate, causing the high-pressure ball valve to rotate, thus opening or closing the oil circuit and controlling the flow of oil. The first throttle valve 5.1 and the second throttle valve 5.2 are installed in the air circuit connecting the auxiliary unit and the test unit to adjust the gas flow rate in the air circuit, control the rotation speed of the swing air motors, and make the switching of the high-pressure ball valve smoother.

[0034] In this embodiment, the test unit includes a first high-pressure ball valve 6.1, a second high-pressure ball valve 6.2, a third high-pressure ball valve 6.3, a fourth high-pressure ball valve 6.4, a fifth high-pressure ball valve 6.5, a sixth high-pressure ball valve 6.7, an eighth high-pressure ball valve 6.8, a first pressure gauge 7.1, a second pressure gauge 7.2, a third pressure gauge 7.3, a fourth pressure gauge 7.4, a fifth pressure gauge 7.5, a sixth pressure gauge 7.6, a seventh pressure gauge 7.7, a first pressure sensor 8.1, a second pressure sensor 8.2, a third pressure sensor 8.3, a fourth pressure sensor 8.4, a fifth pressure sensor 8.5, a sixth pressure sensor 8.6, a first quick connector 9.1, a second quick connector 9.2, a third quick connector 9.3, a fourth quick connector 9.4, a fifth quick connector 9.5, and a sixth quick connector 9.6. Each high-pressure ball valve is connected to a corresponding quick-connect coupling. A pressure gauge and a pressure sensor are installed between the quick-connect coupling and the corresponding high-pressure ball valve. The quick-connect coupling is connected to the hydraulic cylinder under test, and the high-pressure ball valve is connected to a swing-type air motor. The swing-type air motor drives the high-pressure ball valve to rotate, thus opening or closing the oil circuit. In the test unit, the high-pressure ball valve and the hydraulic cylinder under test are connected via a quick-connect coupling and driven to rotate by the swing-type air motor, thus opening or closing the oil circuit and controlling whether oil enters the hydraulic cylinder under test and the on / off state of the oil circuit. The quick-connect coupling is used to connect the high-pressure ball valve and the hydraulic cylinder under test, enabling quick installation and disassembly, improving testing efficiency, and ensuring the sealing of the connection. The pressure gauge is installed between the quick-connect coupling and the high-pressure ball valve, visually displaying the pressure value of the oil in the pipeline, allowing operators to easily observe the pressure situation in real time. The pressure sensor is also installed between the quick-connect coupling and the high-pressure ball valve, converting the pressure change of the oil in the pipeline into an electrical signal, which is transmitted to the PLC control system of the electronic control unit, providing accurate data for pressure monitoring and control. The hydraulic cylinder under test is the object of the test. Through its connection with the test unit, it receives pressurized oil from the oil supply unit and undergoes various performance tests.

[0035] In this embodiment, the electronic control unit includes a PLC control system, a first three-position four-way solenoid directional valve 11.1, a second three-position four-way solenoid directional valve 11.2, and a three-position five-way solenoid directional valve 4. The pressure sensor of the testing unit monitors pressure changes in the hydraulic cylinder and transmits the signal to the PLC control system. The PLC control system controls the switching of the first three-position four-way solenoid directional valve 11.1, the second three-position four-way solenoid directional valve 11.2, and the three-position five-way solenoid directional valve 4, thereby changing the flow direction of the oil in the test bench pipeline. Specifically, the PLC control system is the core of the electronic control unit. It receives signals from the pressure sensor of the testing unit, processes and analyzes the data, and controls the switching of the first three-position four-way solenoid directional valve 11.1, the second three-position four-way solenoid directional valve 11.2, and the three-position five-way solenoid directional valve 4 according to a pre-written program, thus achieving automated control of the test bench. Simultaneously, the system automatically records and saves the time-varying pressure curve data in the pipeline, and automatically determines test results such as the hydraulic cylinder sealing performance based on the pressure curve data. The first three-position four-way solenoid directional valve 11.1 and the second three-position four-way solenoid directional valve 11.2 are controlled by the PLC control system, changing the flow direction of the oil in the oil supply unit pipeline, thereby controlling the movement direction of the hydraulic cylinder and achieving automatic switching of the oil inlet and outlet directions during the test. The three-position five-way solenoid directional valve 4 is controlled by the PLC control system, changing the flow direction of the gas in the auxiliary unit air circuit, controlling the rotation direction of the swing air motor and the gas discharge path, achieving automatic locking of the oil circuit and automatic oil recovery.

[0036] In this embodiment, under no-load conditions, the electronic control unit (ECU) slowly increases the speed of motor 15, gradually raising the system pressure to the minimum starting pressure of the hydraulic cylinder. A fixed pressure is applied to the hydraulic cylinder and held for a certain time to obtain pressure resistance data. During the test, a pressure sensor monitors pressure changes in real time and feeds them back to the ECU's PLC control system. If the pressure is lower than the set lower limit or higher than the set upper limit, the PLC control system issues an alarm and takes corresponding measures. The ECU controls the oil supply unit to inject hydraulic oil into the hydraulic cylinder to the specified pressure value. A pressure sensor detects pressure changes over a certain period to test whether the piston leaks internally. When the test ends, the ECU controls the first three-position four-way solenoid directional valve 11.1 to the left position, reversing the rotation direction of the swing air motor. This locks the branch oil circuit connected to the hydraulic cylinder's charging chamber and connects the branch oil circuit connected to the return oil chamber. The ECU controls the air source 1 to pump gas into the hydraulic cylinder, pushing the piston to move and draining the oil on the other side of the hydraulic cylinder piston back to the oil tank 21, completing oil recovery and preparing for the next round of testing and simulating the complete hydraulic oil flow process. Oil is drained back to oil tank 21 via air source 1. Air source 1 also controls a swing air motor, which in turn controls the high-pressure ball valve, achieving automatic control. The PLC control system of the electrical control unit automatically records and saves the time-varying pressure curve data in the pipeline. Based on the pressure curve data and a pre-programmed procedure, the PLC control system automatically switches the oil inlet / outlet direction, automatically locks the valve circuit, automatically switches the air circuit to drain oil from the hydraulic cylinder, and automatically determines the hydraulic cylinder's sealing performance.

[0037] Specifically, this invention includes an oil supply unit, a testing unit, an auxiliary unit, and an electrical control unit. The oil supply unit provides the required pressure for testing on the test bench. The testing unit monitors the oil pressure in its branch pipeline, and a pressure sensor monitors pressure changes within the hydraulic cylinder and transmits the signal to the PLC control system in the electrical control unit. After the test, the air source 1 in the auxiliary unit injects high-pressure gas into the pipeline, draining the oil back to the oil tank 21, preparing for the next batch of hydraulic cylinder tests. The swing air motor in the auxiliary unit is powered by the air source 1, locking the oil supply unit's inlet pipeline when the air source 1 is filling the hydraulic cylinder. The PLC control system in the electrical control unit receives signals from the pressure sensor and automatically records and analyzes the pressure data. The electrical control unit controls the electromagnetic reversing valve according to a preset program, realizing the functions of switching the oil flow direction on the test bench, the swing air motor driving the high-pressure ball valve to rotate to achieve valve opening, closing, and locking, draining oil from the hydraulic cylinder, and determining the sealing performance of the hydraulic cylinder. This invention of a continuous hydraulic cylinder testing test bench, based on the drainage of oil from the air source 1, realizes fully automatic continuous testing of hydraulic cylinders, thereby improving the efficiency of hydraulic cylinder testing.

[0038] Specifically, hydraulic pump 13 is powered by motor 15, pumping oil from oil tank 21. Impurities are filtered through a filter, and overflow valve 16 provides overflow protection for the hydraulic system. The oil supply unit provides test pressure to the hydraulic cylinder, switching the oil supply and return chambers of the cylinder using a three-position four-way directional valve. The test unit consists of several high-pressure ball valves, pressure gauges, pressure sensors, and quick connectors. The pressure gauges allow direct observation of the oil pressure in the pipeline. The pressure sensor converts the oil pressure into an electrical signal and transmits it to the PLC control system. The auxiliary unit consists of temperature sensor 20, a swing air motor, air source 1, a pneumatic triplet 3, and a throttle valve. Temperature sensor 20 detects the oil temperature in the hydraulic system. Air source 1 controls the rotation of the swing air motor. The function of air source 1 is to introduce air into the pipeline after the hydraulic cylinder test is completed. Pneumatic triplet 3 includes an air filter, a pressure reducing valve, and an oil mist lubricator, which purifies, stabilizes, and lubricates the gas supplied by air source 1. The throttle valve controls the gas flow rate in the air circuit. The electrical control unit (ECU) consists of a PLC control system and an electromagnetic directional valve, ensuring the sequential operation of the test items designed for the test bench. The ECU is characterized by: a pressure sensor in the test unit monitoring pressure changes in the hydraulic cylinder and transmitting the signal to the PLC control system. The PLC control system controls the electromagnetic directional valve to switch directions, thereby changing the flow direction of the oil in the test bench pipeline; a swing air motor is connected to a high-pressure ball valve, and the electrical signal from the PLC control system controls the valve core of a three-position five-way directional valve 4 to actuate, with air source 1 providing rotational power to achieve oil flow and locking. Air source 1 charges the hydraulic cylinder to achieve oil discharge. The oil supply unit is directly connected to the electromagnetic directional valve, and the valve core of the electromagnetic directional valve actuates to achieve oil supply and return to the two oil circuits. One end of the test unit is connected to the swing air motor-high-pressure ball valve assembly, and the other end is connected to the hydraulic cylinder under test via a quick connector. Every two test units are connected to the oil inlet and outlet of one hydraulic cylinder under test. The PLC control system automatically records and saves the time-varying pressure curve data in the pipeline. The PLC control system, based on pressure curve data and a pre-programmed sequence, performs tests including automatically switching the oil inlet / outlet direction, automatically locking corresponding valves, automatically switching the air path to discharge oil from the hydraulic cylinder, and automatically determining the hydraulic cylinder's sealing performance. During hydraulic cylinder testing, the piston's sides serve as the oil supply and return chambers; after testing, the oil supply path is locked, and the piston's sides become the air filling and return chambers.

[0039] Specifically, flow meter 18 records the return oil flow, and pressure gauge in the test unit monitors pipeline pressure. Air source 1 in the auxiliary unit can drain the oil from the hydraulic cylinder and pipeline back to oil tank 21 after the test. A swing air motor in the auxiliary unit drives the high-pressure ball valve to rotate, achieving oil circuit connection and lock-up. Pressure sensor in the electronic control unit monitors pressure changes in the hydraulic cylinder and transmits the signal to the PLC control system. The PLC control system in the electronic control unit controls the solenoid directional valve to change the direction of oil flow in the test bench pipeline. Overflow valve 16 in the oil supply unit can use an electro-proportional overflow valve to achieve active and continuous control of the oil pressure in the pipeline. Temperature sensor 20 in the oil supply unit detects the hydraulic system oil temperature, and is equipped with a cooling fan and heating coil. The PLC controls the hydraulic system oil temperature within the range of room temperature to 90°C. A manual high-pressure ball valve is also provided in the test unit to achieve manual control of pipeline connection and lock-up. Each pair of test units is connected to the oil inlet and outlet of the hydraulic cylinder under test.

[0040] In specific applications, this test bench can perform the following tests: Testing the reciprocating motion of the hydraulic cylinder and expelling air from inside the cylinder. Adjusting the system pressure under no-load conditions to gradually increase the pressure until the hydraulic cylinder starts, testing the minimum starting pressure of the hydraulic cylinder. Applying 1.5 times the nominal pressure to the hydraulic cylinder and holding it for 10 minutes to test its pressure resistance. Injecting hydraulic oil into the hydraulic cylinder to the specified pressure value and monitoring pressure changes over a certain period to test for internal leakage of the piston. Checking for leaks at static seals, joint surfaces, and adjustable parts of the cylinder body by pressurizing the cylinder. Testing low-pressure sealing performance under conditions where the cylinder diameter is greater than 32mm and the minimum pressure is less than 0.5MPa. Testing the stroke by running the hydraulic cylinder to its extreme positions. Specifically, the test bench can perform the following tests on the hydraulic cylinder: Under no-load conditions, slowly increasing the motor speed by 15 rpm to gradually increase the system pressure until the hydraulic cylinder reaches displacement, testing the starting pressure of the hydraulic cylinder. At this time, the high-pressure ball valve group of the swing air motor (first swing air motor 10.1, first high-pressure ball valve 6.1 or second swing air motor 10.2, eighth high-pressure ball valve 6.8) is connected. The manual high-pressure ball valves (first high-pressure ball valve 6.1 to sixth high-pressure ball valve 6.7) are connected. The first three-position four-way solenoid directional valve 11.1 is the directional valve for controlling the air circuit. When the directional valve is in the right position, the first swing air motor 10.1 and the second swing air motor 10.2 rotate in the same direction. At this time, the high-pressure ball valve group of the swing air motor is connected or closed at the same time. The connection or closure of the high-pressure ball valve group of the swing air motor (first swing air motor 10.1, first high-pressure ball valve 6.1 or second swing air motor 10.2, eighth high-pressure ball valve 6.8) is controlled by the three-position five-way solenoid directional valve 4. The left and right positions of the solenoid valve core of the second three-position four-way solenoid directional valve 11.2 move at a certain frequency to test the reciprocating operation of the hydraulic cylinder. When the cylinder diameter is greater than 32mm and the minimum pressure is less than 0.5Mpa, the reciprocating operation is used to test the low-pressure sealing performance. By pressurizing the hydraulic cylinder, check for leaks at the static seals, joints, and adjustable parts of the cylinder body. Move the hydraulic cylinder to its extreme positions and measure the piston rod stroke. Inject hydraulic oil into the hydraulic cylinder to the nominal pressure, and use pressure sensors to detect pressure changes over a certain period to test for internal piston leakage. Given the nominal pressure of a certain model of hydraulic cylinder, apply 1.5 times the nominal pressure and hold for 10 minutes to test the hydraulic cylinder's pressure resistance. After the test, when the first three-position four-way solenoid directional valve 11.1 is in the left position, the first swing air motor 10.1 and the second swing air motor 10.2 rotate in opposite directions. At this time, one set of high-pressure ball valves of the swing air motors is connected, and the other set is locked. The branch oil circuit connected to the hydraulic cylinder's air filling chamber is locked, while the branch oil circuit connected to the hydraulic cylinder's return oil chamber is connected. Air source 1 pumps gas into the hydraulic cylinder, pushing the piston to move and draining the oil on the other side of the hydraulic cylinder piston back to the oil tank 21. The hydraulic cylinder test is complete.More specifically: the test bench is designed for a maximum test pressure of 60 MPa and a maximum flow rate of 45 L / min. The hydraulic pump 13, motor 15, and relief valve 16 in the oil supply unit are selected as needed. The oil tank 21 is equipped with a cooling fan and heating coil, and the oil temperature of the hydraulic system of the test bench is controlled by a PLC within the range of room temperature to 90°C. The hydraulic cylinder testing test bench uses No. 46 anti-wear hydraulic oil as the medium. The test bench can measure hydraulic cylinder diameters ranging from 20 mm to 800 mm.

[0041] Specifically, motor 15 and hydraulic pump 13 are connected via coupling 14. Motor 15 drives the pump blades to rotate, providing power to the pump. Oil in tank 21 is drawn out by hydraulic pump 13, filtered for impurities by the suction filter, and then enters the test unit through a three-position four-way solenoid valve. In the auxiliary unit, after the current batch of hydraulic cylinders is tested, the PLC controls the three-position five-way solenoid valve 4 to actuate, inflating the pipeline and discharging the oil. The oil returns to the oil supply unit through the three-position four-way solenoid valve, is filtered for impurities by the return oil filter, and then returns to tank 21. In the test unit, each swing air motor drives the corresponding high-pressure ball valve to control the flow and locking of the corresponding oil pipeline branch. In the test unit, pressure sensors transmit the pressure signal from the hydraulic cylinder to the PLC control system. The test unit is connected to the hydraulic cylinder's inlet and outlet ports via quick-connect couplings. For hydraulic cylinders with dual (inlet / outlet) ports, every two test units are connected to the oil inlet and outlet ports of one tested component.

[0042] This invention uses an air source 1 to drain oil back to the oil tank 21, controls a swing air motor, and then controls a high-pressure ball valve to achieve automatic control, thereby improving testing efficiency.

[0043] In this embodiment, the oil supply unit operates, with motor 15 driving hydraulic pump 13 via coupling 14. Hydraulic pump 13 draws hydraulic oil from oil tank 21 through suction filter 17, pressurizes it, and outputs it through second check valve 12.2. Between second check valve 12.2 and second three-position four-way solenoid directional valve 11.2, relief valve 16 provides safety protection to prevent excessive system pressure. Pressurized oil flows back to oil tank 21 via second three-position four-way solenoid directional valve 11.2, flow meter 18, and return filter 19, forming an oil supply circuit. The electronic control unit controls the second three-position four-way solenoid directional valve 11.2 to change the direction of oil flow, providing pressurized oil in different directions to the testing unit.

[0044] In this embodiment, the test unit operates, and the high-pressure ball valve is connected to the hydraulic cylinder under test via a quick connector. A pressure gauge and pressure sensor between the quick connector and the high-pressure ball valve monitor the oil pressure in the pipeline in real time. Under no-load conditions, the electronic control unit (ECU) controls the motor 15 to slowly increase its speed, gradually raising the system pressure. When the hydraulic cylinder starts, the pressure sensor transmits a signal to the ECU to obtain the minimum starting pressure of the hydraulic cylinder. A fixed pressure is applied to the inside of the hydraulic cylinder and held for a certain period. The pressure sensor monitors pressure changes in real time and obtains pressure resistance data. If the pressure is lower than the set lower limit or higher than the set upper limit, the ECU issues an alarm and takes corresponding measures. Simultaneously, the ECU controls the oil supply unit to inject hydraulic oil into the hydraulic cylinder to the specified pressure value. The pressure sensor detects pressure changes over a certain period to test whether the piston is leaking internally.

[0045] In this embodiment, the auxiliary unit operates. At the end of the test, the electronic control unit controls the three-position five-way solenoid directional valve 4. The gas output from the air source 1 is processed by the pneumatic triplet 3 (air filter, pressure reducing valve, oil mist lubricator) and then reaches the three-position five-way solenoid directional valve 4 through the first one-way valve 12.1, and is discharged through the first silencer 2.1 or the second silencer 2.2. At the same time, the electronic control unit controls the first three-position four-way solenoid directional valve 11.1 to the left position, and the swing air motor rotates in the opposite direction, locking the branch oil circuit connected to the hydraulic cylinder's air chamber and opening the branch oil circuit connected to the return oil chamber. The air source 1 pumps gas into the hydraulic cylinder, pushing the piston to move and draining the oil on the other side of the hydraulic cylinder piston back to the oil tank 21, completing the oil recovery and preparing for the next round of complete oil circuit flow and pressure test, thus improving test efficiency. The swing air motor drives the high-pressure ball valve to rotate, realizing the connection or locking of the oil circuit. The throttle valve is used to regulate the gas flow in the air circuit, and the temperature sensor 20 monitors the oil temperature in the oil tank 21.

[0046] In this embodiment, the electronic control unit (ECU) controls the PLC control system to receive pressure change signals from the pressure sensor of the test unit and control the first three-position four-way solenoid directional valve 11.1, the second three-position four-way solenoid directional valve 11.2, and the three-position five-way solenoid directional valve 4 to switch directions, thereby changing the flow direction of oil and gas in the test bench pipeline. Simultaneously, the PLC control system automatically records and saves the time-varying pressure curve data in the pipeline, and based on a pre-written program, implements functions such as automatically switching the oil inlet / outlet direction, automatically locking valve circuits, automatically switching the gas circuit to discharge oil from the hydraulic cylinder, and automatically determining the sealing performance of the hydraulic cylinder.

[0047] In this embodiment, the testing unit, oil supply unit, auxiliary unit and electrical control unit are integrated into one unit through integrated design. The units work closely together to realize the integration of functions such as hydraulic cylinder testing, pressure control and oil recovery. The structure is compact and occupies a small area, which improves the practicality and portability of the equipment.

[0048] In this embodiment, fully automatic control of the test bench is achieved through automated control via the PLC control system of the electronic control unit. This includes functions such as automatically switching the oil inlet / outlet direction, automatically locking the valve circuit, automatically switching the air circuit to discharge oil from the hydraulic cylinder, and automatically determining the sealing performance of the hydraulic cylinder. This reduces manual intervention, improves testing efficiency and accuracy, and reduces human error.

[0049] In this embodiment, through the linkage control of air source 1, the auxiliary unit not only realizes the automatic recovery of oil after the test, but also controls the swing air motor through air source 1 to control the opening and closing of the high-pressure ball valve, realizing the automatic control of oil circuit connection or lock-up. This forms a dual application of air source 1 in oil recovery and oil circuit control, which simplifies the system structure and improves the reliability of control.

[0050] In this embodiment, it has comprehensive testing functions, which can complete the detection of multiple key performance indicators such as minimum starting pressure test, pressure resistance test, and internal leakage test of hydraulic cylinder. The pressure sensor monitors pressure changes in real time and feeds them back to the PLC control system, realizing a comprehensive evaluation of the hydraulic cylinder performance and meeting the testing requirements under different working conditions.

[0051] In this embodiment, through data processing and recording, the PLC control system automatically records and saves the time-varying pressure curve data in the pipeline, providing rich historical data for the performance analysis and quality evaluation of the hydraulic cylinder, facilitating subsequent traceability and optimization, and improving the scientificity and reliability of the test results.

[0052] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:

[0053] This system integrates functions to test the reciprocating operation of a hydraulic cylinder and purge internal air. Under no-load conditions, the system pressure is adjusted and gradually increased to the point where the hydraulic cylinder starts, testing its minimum starting pressure. A constant pressure is applied to the hydraulic cylinder and held for a certain time to test its pressure resistance. Hydraulic oil is injected into the cylinder to a specified pressure value, and the system monitors pressure changes over a certain period to test for internal piston leakage. By pressurizing the hydraulic cylinder, leaks are checked at static seals, mating surfaces, and adjustable parts. Low-pressure sealing is tested under conditions with a cylinder diameter greater than 32mm and a minimum pressure below 0.5MPa. The system also tests the stroke by running the hydraulic cylinder to its extreme positions.

[0054] At the end of the test, the three-position five-way solenoid directional valve 4 is controlled by the electronic control unit. The gas output from the air source 1 is processed by the pneumatic triplet 3 (air filter, pressure reducing valve, oil mist lubricator) and then reaches the three-position five-way solenoid directional valve 4 through the first one-way valve 12.1, and is discharged through the first silencer 2.1 or the second silencer 2.2. At the same time, the electronic control unit controls the first three-position four-way solenoid directional valve 11.1 to the left position, and the swing air motor rotates in the opposite direction, locking the branch oil circuit connected to the hydraulic cylinder's air chamber and opening the branch oil circuit connected to the return oil chamber. The air source 1 pumps gas into the hydraulic cylinder, pushing the piston to move and draining the oil on the other side of the hydraulic cylinder piston back to the oil tank 21, completing the oil recovery and preparing for the next round of complete oil circuit flow and pressure test. This complete simulation test of the complete flow state of hydraulic oil from the oil cylinder to the oil circuit improves test efficiency.

[0055] The operation of returning the hydraulic fluid to the oil tank 21 via air source 1 completes the oil recovery, preparing for the next round of complete oil circuit flow and pressure testing. This fully simulates the complete flow state of hydraulic oil from the cylinder to the oil circuit, improving testing efficiency. Furthermore, air source 1 controls the swing air motor to operate the high-pressure ball valve, achieving automatic control. That is, air source 1 is linked to control the auxiliary unit. Through air source 1, not only is the automatic recovery of hydraulic fluid achieved after the test, but the swing air motor is also controlled by air source 1 to control the opening and closing of the high-pressure ball valve, realizing automatic control of oil circuit connection or lockout. This forms a dual application of air source 1 in oil recovery and oil circuit control, simplifying the system structure and improving control reliability.

[0056] After the test, the air source 1 injects high-pressure gas into the pipeline and discharges the oil back to the oil tank 21 to prepare for the next batch of hydraulic cylinder tests. The swing air motor in the auxiliary unit is powered by the air source 1. When the air source 1 fills the hydraulic cylinder with air, it locks the oil supply unit inlet pipeline to achieve rapid and efficient emptying of the oil in the pipeline and simulates the complete oil flow state from the oil tank 21 to the hydraulic cylinder.

[0057] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An integrated hydraulic cylinder testing bench, characterized in that, It includes a testing unit, an oil supply unit, an auxiliary unit, and an electronic control unit. The testing unit is connected to the oil supply unit and the auxiliary unit, respectively. The testing unit, the oil supply unit, and the auxiliary unit are all connected to the electronic control unit. The oil supply unit provides the pressure required for testing to the testing unit. The testing unit is used to test the hydraulic cylinder oil pressure and transmit the pressure change signal in the hydraulic cylinder to the electronic control unit. The electronic control unit is used to control the solenoid valve to change the direction of oil flow in the test bench pipeline. The auxiliary unit is used to inject high-pressure gas into the pipeline after the test and discharge the oil back to the oil tank. The test unit includes several test branches. Each test branch is equipped with a high-pressure ball valve, a quick connector, a pressure gauge, and a pressure sensor. The high-pressure ball valve is connected to the quick connector. A pressure sensor and a pressure gauge are also provided between the high-pressure ball valve and the quick connector. The quick connector is connected to the corresponding hydraulic cylinder. A corresponding high-pressure ball valve and a swing air motor combination are also provided between the test branch and the air circuit of the auxiliary unit. The swing air motor drives the high-pressure ball valve to rotate, realizing the pneumatic connection or locking of the oil circuit. The test branches are set in pairs. The auxiliary unit includes an air source connected to a pneumatic triplet, which is connected to a first one-way valve. The first one-way valve is connected to a three-position five-way solenoid directional valve of the electronic control unit. A first silencer and a second silencer are connected to the three-position five-way solenoid directional valve. The pneumatic triplet includes an air filter, a pressure reducing valve, and an oil mist lubricator connected in series. The auxiliary unit also includes a temperature sensor, a first swing air motor, a second swing air motor, a first throttle valve, and a second throttle valve. The temperature sensor is located in the oil tank. The first swing air motor, the second swing air motor, the first throttle valve, and the second throttle valve are located in the air path connecting the auxiliary unit and the test unit. It also includes: the first three-position four-way solenoid directional valve, the sixth high-pressure ball valve, and the eighth high-pressure ball valve; During testing, the first three-position four-way solenoid directional valve controls the sixth and eighth high-pressure ball valves, the swing air motor high-pressure ball valve group is connected, and the manual high-pressure ball valve is connected. The first three-position four-way solenoid directional valve is the directional valve for controlling the air path. When the first three-position four-way solenoid directional valve is in the right position, the first swing air motor and the second swing air motor rotate in the same direction. At this time, the swing air motor high-pressure ball valve group is connected or closed at the same time. When the test ends, the electronic control unit controls the first three-position four-way solenoid directional valve to the left position, and the first swing air motor and the second swing air motor rotate in opposite directions, locking the branch oil circuit connected to the hydraulic cylinder's air chamber and opening the branch oil circuit connected to the return oil chamber. The electronic control unit controls the air source to pump air into the hydraulic cylinder, pushing the piston to move and draining the oil on the other side of the hydraulic cylinder piston back to the oil tank, completing the oil recovery and preparing for the next round of testing. The oil is drained back to the oil tank via an air source, and the first and second swing air motors are controlled by the air source, which in turn control the first and second high-pressure ball valves, achieving dual control through air-liquid linkage.

2. The integrated hydraulic cylinder testing bench as described in claim 1, characterized in that, The oil supply unit includes a motor, which is connected to a hydraulic pump via a coupling. The hydraulic pump is connected to a suction oil filter, which is connected to an oil tank. The hydraulic pump is connected to a second three-position four-way solenoid valve of the electronic control unit via a second check valve. The second three-position four-way solenoid valve is connected to a flow meter, which is connected to a return oil filter, which is connected to an oil tank. An overflow valve is connected between the second check valve and the second three-position four-way solenoid valve.

3. The integrated hydraulic cylinder testing bench as described in claim 1, characterized in that, The electronic control unit includes a PLC control system, a first three-position four-way solenoid directional valve, a second three-position four-way solenoid directional valve, and a three-position five-way solenoid directional valve. The pressure sensor of the test unit monitors the pressure change in the hydraulic cylinder and transmits the signal to the PLC control system. The PLC control system controls the first three-position four-way solenoid directional valve, the second three-position four-way solenoid directional valve, and the three-position five-way solenoid directional valve to switch directions, thereby changing the flow direction of oil and air in the test bench pipeline.

4. The integrated hydraulic cylinder testing bench as described in claim 1, characterized in that, Under no-load conditions, the electronic control unit controls the motor speed to be increased slowly, and the system pressure is gradually increased to the minimum starting pressure of the hydraulic cylinder when it starts. By applying a fixed pressure to the inside of the hydraulic cylinder and holding the pressure for a certain period of time, pressure resistance data is obtained. During the test, the pressure sensor monitors the pressure change in real time and feeds it back to the PLC control system of the electronic control unit. If the pressure is lower than the set lower limit or higher than the set upper limit, the PLC control system will issue an alarm and take corresponding measures.

5. The integrated hydraulic cylinder testing bench as described in claim 1, characterized in that, The electronic control unit controls the oil supply unit to inject hydraulic oil into the hydraulic cylinder to a specified pressure value, and uses a pressure sensor to detect pressure changes over a certain period of time to test whether the piston leaks internally.

6. The integrated hydraulic cylinder testing bench as described in claim 1, characterized in that, The PLC control system of the electrical control unit automatically records and saves the time-varying pressure curve data in the pipeline. Based on the pressure curve data, the PLC control system realizes the test functions of automatically switching the oil inlet and outlet direction, automatically locking the valve circuit, automatically switching the air circuit to discharge the oil inside the hydraulic cylinder, and automatically judging the sealing performance of the hydraulic cylinder.

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