A performance test system and method for a servo cylinder

Abstract

The application relates to a performance test system and method for a servo oil cylinder, comprising a hydraulic system, wherein the hydraulic system comprises a hydraulic pump, a servo spool valve, an electric cylinder and a control module, the hydraulic pump is communicated with the servo spool valve, the oil port of the servo spool valve is communicated with the servo oil cylinder, the piston rod of the servo oil cylinder is controlled to be extended and retracted, the electric cylinder is connected with the valve core of the servo spool valve and is used for adjusting the position of the valve core, and the electric cylinder is connected with the control module. The performance test system and method for the servo oil cylinder can simulate the working condition of the servo oil cylinder, can monitor and record test data in real time, and can verify the performance and reliability of the servo oil cylinder.

Description

Technical Field

[0001] This invention relates to the field of hydraulic cylinder testing technology, and in particular to a performance testing system and method for servo cylinders. Background Technology

[0002] Hydraulic test benches are primarily used for performance testing of hydraulic pumps, hydraulic motors, hydraulic valves, and hydraulic cylinders, and can test various specifications and series of hydraulic components. They are widely used in the performance testing of mechanical hydraulic devices in various industries such as aerospace, shipbuilding, mining and metallurgy, marine equipment, and intelligent equipment. With the rapid development of modern technology and manufacturing, there are increasingly more pressure-controlled equipment projects, making hydraulic test benches crucial for verifying equipment performance and reliability.

[0003] Straight-wing propellers are critical devices on warships, and servo cylinders, as the core components of straight-wing propellers, directly affect the warship's combat performance. Due to their unique operating conditions, servo cylinders on warships require fast response speeds and high homing accuracy, which places new demands on test benches. Currently, servo cylinder tests are generally conducted using conventional test benches, lacking testing equipment specifically designed to address the motion characteristics of servo cylinders. Summary of the Invention

[0004] To address the problems of existing technologies, this invention provides a performance testing system and method for servo hydraulic cylinders that uses a servo-controlled electric cylinder to simulate the motion of a pitch-controlled propeller. Simultaneously, by adding sensors to the servo cylinder to collect signals and upload them to the control module for real-time monitoring and recording, the system achieves servo cylinder operating condition simulation and can verify the performance and reliability of the servo cylinder.

[0005] The specific technical solution is as follows: A performance testing system for a servo cylinder includes a hydraulic system, which includes a hydraulic pump, a servo slide valve, an electric cylinder, and a control module. The hydraulic pump is connected to the servo slide valve, and the oil port of the servo slide valve is connected to the servo cylinder to control the extension and retraction of the piston rod of the servo cylinder. The electric cylinder is connected to the valve core of the servo slide valve to adjust the position of the valve core. The electric cylinder is connected to the control module.

[0006] As a preferred embodiment, the servo spool valve has a first oil port, a second oil port, and an inlet. The first and second oil ports are used to communicate with the rod-side chamber and rodless chamber of the servo cylinder, respectively, and the inlet is connected to the hydraulic pump.

[0007] As a preferred embodiment, the hydraulic system includes a relief valve disposed between the hydraulic pump and the servo spool valve.

[0008] As a preferred embodiment, the hydraulic system includes a thermometer, a pressure gauge, and a flow meter.

[0009] As a preferred embodiment, the performance testing system also includes a pressure sensor and a displacement sensor, which are mounted on the servo cylinder and electrically connected to the control module.

[0010] As a preferred embodiment, the servo slide valve and electric cylinder are mounted on a test bench.

[0011] A performance testing method for servo cylinders includes the following steps:

[0012] S100: Obtain valve core and valve body data of the servo spool valve;

[0013] S200: The valve core of the servo slide valve is adjusted to the neutral position by the electric cylinder. At this time, the first and second oil ports of the servo slide valve are closed, and the piston rod of the servo cylinder is kept in the neutral position under the pre-compression of the built-in spring of the servo cylinder.

[0014] S300: Set the system pressure, start the hydraulic station, the control module detects the flow signal, and controls the flow through the proportional valve to meet the test requirements;

[0015] S400: Start the preset program in the control module to control the electric cylinder to start the test, and the control module records the displacement curve of the servo cylinder.

[0016] As a preferred embodiment, in step S200, the accuracy of the valve core pre-opening during the debugging of the servo slide valve is 0.02~0.03mm.

[0017] As a preferred embodiment, the servo cylinder is used for the controllable pitch propeller of a ship.

[0018] As a preferred option, the servo cylinder is mounted on a test bench during performance testing.

[0019] The technical effects of this invention are as follows: The performance testing system and method for servo cylinders of this invention can simulate the working conditions of servo cylinders, monitor and record test data in real time, thereby verifying the performance and reliability of servo cylinders. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of a performance testing system for a servo hydraulic cylinder according to this embodiment.

[0021] Figure 2 This is a schematic diagram of the control module in this embodiment.

[0022] Figure 3 This is a schematic diagram of the valve core of the servo slide valve in this embodiment.

[0023] Figure 4 This is a schematic diagram of the servo cylinder formation record in this embodiment.

[0024] Figure 5This is a side view of the test bench for the servo cylinder in this embodiment.

[0025] Figure 6 This is a perspective view of the test bench for the servo hydraulic cylinder in this embodiment.

[0026] Figure 7 This is a schematic diagram of the oil tank in this embodiment.

[0027] Figure 8 This is a schematic diagram of the leakage point in this embodiment.

[0028] Figure 9 This is a schematic diagram of the filter-type oil shield of this embodiment.

[0029] Figure 10 This is a schematic diagram of the test rod assembly in this embodiment.

[0030] Figure 11 This is another schematic diagram of the test rod assembly in this embodiment.

[0031] Figure 12 This is a schematic diagram of the transverse servo cylinder test in this embodiment.

[0032] Figure 13 This is a schematic diagram of the longitudinal servo cylinder test in this embodiment. Detailed Implementation

[0033] The substantive features and advantages of the present invention will be further described below with reference to examples, but the present invention is not limited to the listed embodiments.

[0034] like Figures 1 to 4 As shown, this embodiment of a performance testing system for a servo cylinder includes a hydraulic system comprising a hydraulic pump 1, a servo valve 2, an electric cylinder 3, and a control module. The hydraulic pump 1 is connected to the servo valve 2, and the oil port of the servo valve 2 is connected to the servo cylinder 10, controlling the extension and retraction of the piston rod. The electric cylinder 3 is connected to the valve core 21 of the servo valve 2 and is used to adjust the position of the valve core 21. The electric cylinder 3 is also connected to the control module. Hydraulic systems generally have two energy sources: constant current sources and constant pressure sources. The working pressure of a constant current source system varies with the external load, while the working pressure of a constant pressure source system is set by an overflow valve and adjusted by regulating the throttling orifice of a control valve to correspond to the external load. Therefore, constant pressure source systems suffer from overflow and throttling losses, and their efficiency is not as high as that of constant current source systems. However, constant pressure source systems have better linearity and are often used in applications with high performance requirements. Servo cylinder components have high requirements for system performance (linearity, response, and accuracy), therefore a constant pressure source is used. The time requirement for pitch adjustment of a ship under idling and full-speed conditions is simulated by adjusting the flow rate using a constant-pressure variable pump. That is, the greater the flow rate, the faster the cylinder moves and the shorter the pitch adjustment time.

[0035] In the above technical solution, hydraulic pump 1 supplies hydraulic oil from the hydraulic station to the performance testing system. Servo spool valve 2 controls the extension and retraction of the piston rod of the servo cylinder. Electric cylinder 3 acts as the actuator for adjusting the servo spool valve core, controlled by a servo motor, achieving an accuracy of 0.01mm, meeting the accuracy requirement of 0.02~0.03mm for the valve core pre-opening 211 during servo cylinder assembly spool valve debugging. This opening K is a positive opening, intended to increase flow gain. Further reducing the opening would result in a zero opening, with no flow gain. An excessively large opening would cause mid-position leakage. Simulation models and experiments have proven that a larger opening does not necessarily lead to higher flow gain. The control module uses a preset motion function on the industrial control computer to drive the electric cylinder 3, simulating the motion trajectory of the controllable pitch propeller to proportionally control the valve core. In this embodiment, the control module includes an industrial control computer, a PLC module, a power supply module, and a display. The industrial control computer is connected to the PLC module, the power supply module, and the display.

[0036] In this embodiment, the servo spool valve 2 has a first port A, a second port B, and an inlet port P. The first port A and the second port B are used to communicate with the rod-side chamber and the rodless chamber of the servo cylinder, respectively, and the inlet port P is connected to the hydraulic pump 1. In this embodiment, the first port A is connected to the rod-side chamber of the servo cylinder, and the second port B is connected to the rodless chamber of the servo cylinder. When the valve core 21 is in the neutral position and the servo cylinder stops, the valve core 21 moves to the left, oil enters through the second port B, oil returns through the first port A, and the servo cylinder piston rod extends; when the valve core moves to the left, oil enters through the first port A, oil returns through the second port B, and the servo cylinder piston rod retracts. The hydraulic system includes a relief valve 4, which is disposed between the hydraulic pump 1 and the servo spool valve 2. The hydraulic system includes a thermometer 41, a pressure gauge 42, and a flow meter 43, which are used to measure temperature, pressure, and flow data, respectively. The hydraulic system also includes a filter 44 for filtering the oil. The performance testing system also includes a pressure sensor and a displacement sensor, which are disposed on the servo cylinder and electrically connected to the control module. By installing pressure sensors and magnetostrictive displacement sensors on the servo cylinder to collect signals and upload them to the industrial control computer for real-time monitoring and recording, the working condition simulation of the servo cylinder component is realized from the design perspective.

[0037] This embodiment provides a performance testing method for a servo cylinder, comprising the following steps: S100: acquiring data on the valve core and valve body of the servo slide valve; S200: using the electric cylinder 3 to adjust the valve core of the servo slide valve 2 to the neutral position, at which point both the first oil port A and the second oil port B of the servo slide valve 2 are closed, and the piston rod of the servo cylinder remains in the neutral position under the preload of the built-in spring of the servo cylinder 10; S300: setting the system pressure, starting the hydraulic station, the control module detecting the flow signal, and controlling the flow rate through the proportional valve to meet the test requirements; S400: starting the preset program in the control module, controlling the electric cylinder to start the test, and the control module recording the displacement curve of the servo cylinder.

[0038] In the above technical solution, before the test begins, the servo cylinder is installed on the test bench. The servo cylinder is used for the controllable pitch propeller of the ship. Since the transverse servo cylinder and the longitudinal servo cylinder jointly drive the controllable pitch propeller, the transverse servo cylinder can be tested first, and then the longitudinal servo cylinder can be tested. After the transverse servo cylinder test is completed, the longitudinal servo cylinder is replaced, and the above process is repeated. The preset program in the control module can be set in the industrial control computer. The preset program is the movement trajectory of the electric cylinder, that is, full right rudder means the transverse cylinder piston rod retracts to the bottom, and full left rudder means the transverse cylinder piston rod extends to the top. Various working conditions can be simulated according to requirements. In this embodiment, in step S200, the accuracy of the valve core pre-opening during the servo slide valve debugging is 0.02~0.03mm.

[0039] like Figure 4 As shown, the displacement curves of the two cylinders can be obtained through the above technical solution. Using an industrial control computer to combine the two curves, the actual total stroke of the lateral and longitudinal cylinders in this experiment can be calculated. Since the motion of the lateral and longitudinal servo cylinders is determined, and the transmission and motion forms between the components of the controllable pitch propeller are also determined, the motion trajectories of the two types of cylinders can be calculated under the condition of no manufacturing or installation errors. By comparing the theoretical total stroke curve and the actual total stroke curve, it can be determined whether the set of cylinders is qualified. Furthermore, a qualified total stroke curve can be obtained by matching the actual stroke curves of each lateral and longitudinal cylinder.

[0040] like Figures 5 to 13 As shown, a test bench for a servo cylinder in this embodiment includes a base 5, a mounting frame 6, and a support frame 7. The mounting frame 6 and the support frame 7 are arranged opposite to each other on the base 5. The mounting frame 6 includes a first mounting hole 61 and a second mounting hole 62, with the second mounting holes 62 symmetrically arranged on both sides of the first mounting hole 61. The support frame 7 has positioning holes 71, which are respectively arranged corresponding to the second mounting holes 62. The bottom of the base 5 is provided with an oil tank 51, and the base 5 is provided with an oil drain port 52. The oil tank 51 is connected to the oil tank 8 through the oil drain port 52. In the above technical solution, the servo cylinder 10 and the servo slide valve 2 are mounted on the mounting frame 6. Through the symmetrically arranged second mounting holes 62, the mounting frame can be used for horizontal servo cylinders and vertical servo cylinders. During the testing of horizontal and vertical servo cylinders (such as...), Figure 12 and 13As shown, the servo slide valves are symmetrically positioned, eliminating the need to disassemble and replace the mounting bracket 6 when testing the horizontal or vertical servo cylinders, thus improving work efficiency. During installation, the servo cylinders are hoisted by a crane and mounted on the mounting bracket with six screws. By setting an oil tank 51 below the base 5, the oil leaking from the servo slide valve 2 can enter the oil tank. An oil drain port is opened at the bottom of the oil tank, and the oil in the oil tank returns to the oil tank under gravity due to the height difference, allowing the oil to be reused during long-term running-in tests. The base 5 is formed by welding channel steel, and the bottom surface of the base is welded with thin steel plates to form the oil tank. In this embodiment, the mounting bracket 6 and the support frame 7 are vertically arranged.

[0041] In this embodiment, the mounting bracket 6 is positioned at the center of gravity of the test bench for greater stability during testing. It measures 2300mm in length and 1200mm in width, with a total weight of approximately 240kg, and can be placed in workshops, high and low temperature chambers, or swing platforms according to testing requirements. The second mounting hole 62 houses the servo valve 2. The leakage point 22 of the servo valve 2 is equipped with a filter-type oil shield 23 to prevent contamination and waste caused by oil spraying. The filter-type oil shield 23 is secured to the annular groove 24 of the servo valve 2 for easy assembly. The filter-type oil shield 23 includes a fixing ring 231 and a filter screen 232. The filter screen 232 is mounted on the fixing ring 231 and is arranged in a cylindrical shape to cover the leakage point 22. The fixing ring is made of copper wire.

[0042] In this embodiment, the first mounting hole 61 is used to install the servo cylinder 10, and the positioning hole 71 is used to install the electric cylinder 3. The servo cylinder 10, the electric cylinder 3, and the servo slide valve 2 are connected by a test rod assembly 9. The test rod assembly 9 enables the electric cylinder 3 to drive the servo cylinder and the servo slide valve. The test rod assembly 9 includes a short connecting rod 91, a horizontal connecting rod 92, and an adjusting rod 93. One end of the short connecting rod 91 is connected to the electric cylinder 3, and the other end is connected to the horizontal connecting rod 92. One end of the horizontal connecting rod 92 is connected to the servo cylinder 10. The adjusting rod 93 is connected to both the horizontal connecting rod 92 and the servo slide valve 2. The adjusting rod 93 has a threaded adjusting double-ended rod 931. The adjusting rod 93 adjusts the center position of the valve core 21 of the servo slide valve 2 by using a threaded adjusting double-ended rod with different rotation directions at both ends (turning right to adjust closer, turning left to adjust farther), in order to compensate for the difference between the center position of the cylinder and the center position of the slide valve caused by machining errors. It also serves as the control rod of the servo slide valve 2, directly controlling the position of the servo slide valve core and controlling the opening and closing of the valve port. The horizontal connecting rod 92 serves as a structural rod connecting the servo cylinder piston rod, the servo slide valve piston rod, and the electric cylinder lead screw. It also limits the movement of the servo slide valve spool under hydraulic pressure, thus determining the position of the servo slide valve spool. The test rod assembly 9 is connected to the servo cylinder, electric cylinder, and servo slide valve via pins 20.

[0043] During operation, the electric cylinder 3 transmits force to the horizontal connecting rod 92 via the short connecting rod 91, thereby driving the adjusting rod 93 to move the valve core of the servo slide valve 2 in a reciprocating linear motion. The short connecting rod 91 and the horizontal connecting rod 92 are fitted with a shaft hole, with a fit tolerance of D8 / h8. The material of the rod assembly and pin is selected as 45# steel after quenching and tempering. The adjusting rod, horizontal rod, and servo slide valve are connected by pins and spherical bearings to ensure that the servo cylinder, servo slide valve, and electric cylinder will not jam due to machining and installation errors during relative movement. The test linkage is equivalent to a four-bar linkage. The electric cylinder, as the driving element, is equivalent to a single-degree-of-freedom sliding joint; the driven servo valve core is also equivalent to a single-degree-of-freedom sliding joint; and the servo cylinder piston rod connected by the cross link is also equivalent to a single-degree-of-freedom sliding joint. The pins between the adjusting rod and the servo valve core, and between the electric screw and the short connecting rod, do not affect the movement of the output component (servo valve core) and are considered as local degrees of freedom. Therefore, according to the mechanical degree-of-freedom calculation method: degree of freedom F = 3n - 2p l -P H The degree of freedom of the test linkage is F = 3 × 4 - 2 × 3 - 3 = 1, so the mechanism has a definite motion. If the short connecting rod is removed, the degree of freedom of the test linkage becomes F = 3 × 3 - 2 × 3 - 3 = 0, and the linkage cannot move. Therefore, the function of the short connecting rod is to increase the degree of freedom of the linkage, giving it a definite motion trajectory.

[0044] It should be noted that the above preferred embodiments are merely illustrative of the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A performance test system for a servo cylinder, characterized by The system includes a hydraulic system comprising a hydraulic pump, a servo valve, an electric cylinder, and a control module. The hydraulic pump is connected to the servo valve, and the oil port of the servo valve is connected to the servo cylinder to control the extension and retraction of the piston rod of the servo cylinder. The electric cylinder is connected to the valve core of the servo valve for adjusting the valve core position. The electric cylinder is also connected to the control module. The servo valve and the electric cylinder are mounted on a test bench, which includes a base, a mounting bracket, and a support frame. The mounting bracket includes a first mounting hole and a second mounting hole, with the second mounting hole symmetrically arranged on the first mounting hole. On both sides of the mounting hole, the servo cylinder is installed in the first mounting hole, and the servo slide valve is installed in the second mounting hole. The servo cylinder, electric cylinder, and servo slide valve are connected by a test rod assembly. The test rod assembly includes a short connecting rod, a horizontal connecting rod, and an adjusting rod. One end of the short connecting rod is connected to the electric cylinder, and the other end is connected to the horizontal connecting rod. One end of the horizontal connecting rod is connected to the servo cylinder. The adjusting rod is connected to the horizontal connecting rod and the servo slide valve respectively. The electric cylinder transmits force to the horizontal connecting rod through the short connecting rod, which drives the adjusting rod to drive the valve core of the servo slide valve to perform reciprocating linear motion.

2. The performance test system for a servo ram as defined in claim 1, wherein, The servo spool valve has a first oil port, a second oil port, and an inlet. The first and second oil ports are used to communicate with the rod-side chamber and rodless chamber of the servo cylinder, respectively, and the inlet is connected to the hydraulic pump.

3. The performance test system for a servo ram as defined in claim 2, wherein, The hydraulic system includes a relief valve, which is located between the hydraulic pump and the servo spool valve.

4. The performance test system for a servo ram as defined in claim 3, wherein, The hydraulic system includes a thermometer, a pressure gauge, and a flow meter.

5. The performance test system for a servo ram as defined in claim 4, wherein, The performance testing system also includes pressure sensors and displacement sensors, which are mounted on the servo cylinder and electrically connected to the control module.

6. A performance test method for a servo cylinder, applied to the performance test system for a servo cylinder according to any one of claims 1 to 5, characterized by, Includes the following steps: S100: Obtain valve core and valve body data of the servo spool valve; S200: The valve core of the servo slide valve is adjusted to the neutral position by the electric cylinder. At this time, the first and second oil ports of the servo slide valve are closed, and the piston rod of the servo cylinder is kept in the neutral position under the pre-compression of the built-in spring of the servo cylinder. S300: Set the system pressure, start the hydraulic station, the control module detects the flow signal, and controls the flow through the proportional valve to meet the test requirements; S400: Start the preset program in the control module to control the electric cylinder to start the test, and the control module records the displacement curve of the servo cylinder.

7. The performance test method for a servo cylinder according to claim 6, characterized by, In step S200, the accuracy of the valve core pre-opening during the debugging of the servo slide valve is 0.02~0.03mm.

8. The performance test method for a servo cylinder according to claim 7, characterized by, The servo cylinder is used for the ship's controllable pitch propeller.

9. The performance test method for a servo cylinder according to claim 8, wherein During performance testing, the servo cylinder is mounted on a test bench.

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