A performance and reliability test bench for hydrostatically actuated hydraulic cylinders

Abstract

This invention relates to the field of performance testing technology for hydrostatic cylinders, and discloses a performance and reliability test bench for hydrostatic cylinders. The bench includes a mounting base, a hydrostatic cylinder under test, a moving unit, and a lateral loading mechanism. Pressure acquisition points are located at both ends of the hydrostatic cylinder under test, and pressure sensors are externally connected to these points. A first displacement sensor is built into the hydrostatic cylinder under test. The hydrostatic cylinder under test is fixedly mounted on the mounting base, and the lateral loading mechanism is fixed to the moving unit. The lateral loading mechanism is connected to the piston rod of the hydrostatic cylinder under test, and the lateral loading mechanism and the piston rod are perpendicular to each other. The hydrostatic cylinder under test can drive the lateral loading mechanism to move synchronously through the moving unit. The technical solution of this invention can test the durability, friction performance, load-bearing capacity, and uniformity of the hydrostatic cylinder under test.

Description

Technical Field

[0001] This invention relates to the field of performance testing technology for hydrostatic cylinders, and specifically to a performance and reliability testing bench for hydrostatic cylinders. Background Technology

[0002] Hydraulic servo actuators are widely used in testing and experimentation in the automotive, aerospace, rail, and civil engineering fields. They can simulate the loads that components experience during use and test the performance, strength, and fatigue performance of these components. The hydraulic servo actuator is a key component in the entire test bench. Because hydrostatic actuators have advantages such as long service life, high control frequency, and high precision, they are typically used to simulate loads.

[0003] Currently, most hydrostatic actuators are imported from abroad. The purchase and maintenance costs of hydrostatic actuators are relatively high, and foreign manufacturers have long monopolized the domestic market. In recent years, a few domestic manufacturers of electro-hydraulic servo testing equipment have begun to independently develop and produce hydrostatic actuators. However, their performance testing capabilities are limited, lacking effective testing platforms to detect various performance parameters. Existing testing platforms can only detect the starting pressure and internal / external leakage of hydrostatic actuators, but cannot accurately detect parameters related to measurement and control accuracy, such as durability, load-bearing capacity, uniformity, and friction performance. Therefore, there is an urgent need to design a performance and reliability testing platform for hydrostatic actuators to test key indicators such as friction performance, load-bearing capacity, uniformity, and durability. Summary of the Invention

[0004] The present invention aims to provide a performance and reliability test bench for hydrostatic actuated cylinders, which can test the durability, friction performance, load-bearing capacity and uniformity of the hydrostatic actuated cylinders under test.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a performance and reliability test bench for a hydrostatic actuated cylinder, comprising a mounting base, a hydrostatic actuated cylinder under test, a moving unit, and a lateral loading mechanism. Pressure acquisition points are provided at both ends of the hydrostatic actuated cylinder under test, and pressure sensors are externally connected to these points. A first displacement sensor is built into the hydrostatic actuated cylinder under test. The hydrostatic actuated cylinder under test is fixedly mounted on the mounting base. The lateral loading mechanism is fixed to the moving unit, and a force sensor is fixed to the lateral loading mechanism. The lateral loading mechanism is connected to the piston rod of the hydrostatic actuated cylinder under test, and the lateral loading mechanism and the piston rod of the hydrostatic actuated cylinder under test are perpendicular to each other. The hydrostatic actuated cylinder under test can drive the lateral loading mechanism to move synchronously through the moving unit.

[0006] The beneficial effects of this scheme are as follows: Pressure acquisition points are set at both ends of the hydrostatic actuated cylinder under test. By connecting pressure sensors to these points, the starting pressure of the hydrostatic actuated cylinder can be detected. When testing the friction performance of the hydrostatic actuated cylinder, a constant lateral pressure is applied to the piston rod of the cylinder via a lateral loading mechanism to start the cylinder. The piston rod of the cylinder then reciprocates. Since the cylinder can drive the lateral loading mechanism synchronously through a moving unit, the lateral loading mechanism can apply a constant lateral pressure to the piston rod of the cylinder in real time. The pressure is detected by a pressure sensor at both ends of the tested hydrostatic actuated cylinder. The pressure difference between the two ends of the tested hydrostatic actuated cylinder is calculated and used to characterize the friction performance of the tested hydrostatic actuated cylinder. At the same time, the durability performance of the tested hydrostatic actuated cylinder is judged by detecting the number of reciprocating loads that the piston rod of the tested hydrostatic actuated cylinder can withstand under constant lateral pressure. By simulating the dynamic alternating lateral pressure of the lateral loading mechanism that moves synchronously with the tested hydrostatic actuated cylinder, the durability performance of the tested hydrostatic actuated cylinder can be more comprehensively evaluated, thereby shortening the testing and verification cycle of the tested hydrostatic actuated cylinder.

[0007] When testing the load-bearing capacity of a hydrostatic actuated cylinder, the piston rod of the cylinder is extended to a fixed length. Lateral pressure is applied to the piston rod through a lateral loading mechanism, and the lateral pressure is continuously increased. When the pressure of the hydrostatic actuated cylinder does not change, the lateral pressure borne by the cylinder is the maximum load-bearing capacity of the cylinder. The maximum load-bearing capacity of the hydrostatic actuated cylinder can be detected by a force sensor.

[0008] When testing the uniformity of the hydrostatic actuated cylinder, a constant lateral pressure is applied to the piston rod of the cylinder using a lateral loading mechanism. Under this constant lateral pressure, the cylinder is activated, and the piston rod reciprocates. Because the stroke of the cylinder is relatively long, if the gap between the cylinder and its piston rod is uneven, the lateral pressure applied in different stroke segments will be unbalanced. The uniformity of the cylinder's stroke is detected by the magnitude of the fluctuation in the applied lateral pressure. If the stroke of the cylinder is uneven, it may be due to problems in the machining or assembly process.

[0009] In summary, this technical solution can test the durability, friction performance, load-bearing capacity, and uniformity of the hydrostatic actuated cylinder under test.

[0010] Furthermore, the moving unit includes a fixed frame and a moving slide. The length direction of the fixed frame is parallel to the actuating cylinder of the hydrostatic pressure being measured. A guide rail is fixed on the fixed frame, and a slider is fixed on the moving slide, with the slider slidably mounted on the guide rail.

[0011] The beneficial effects of this scheme are as follows: the extension and retraction of the piston rod on the tested static pressure actuated cylinder can drive the lateral loading mechanism to move synchronously along the guide rail, thereby enabling the lateral loading mechanism to apply lateral pressure to the tested static pressure actuated cylinder in real time. At the same time, since the length direction of the fixed frame is parallel to the tested static pressure actuated cylinder, the test results are more reliable.

[0012] Furthermore, the lateral loading mechanism includes a lateral loading actuation cylinder, a vertical connecting unit, and a horizontal connecting unit. The piston rod of the lateral loading actuation cylinder is hinged to the horizontal connecting unit, and the lateral loading actuation cylinder is fixed on the vertical connecting unit.

[0013] The beneficial effects of this scheme are as follows: Since the piston rod of the lateral loading actuation cylinder is hinged to the horizontal connecting unit, the rotational degree of freedom of the lateral loading actuation cylinder along the axial direction of the piston rod of the tested hydrostatic actuation cylinder is retained, ensuring that there is no transitional constraint between the loading actuation cylinder and the test piece, reserving spatial degree of freedom, and compensating for installation and processing errors.

[0014] Furthermore, the vertical connection unit includes a pin seat and a connecting plate. There are two pin seats, which are fixed on the upper and lower sides of the movable slide respectively. The connecting plate is located between the two pin seats, and both ends of the connecting plate are hinged to the pin seats. The connecting plate is provided with a round hole. The lateral loading actuation cylinder is fixed on the connecting plate, and the piston rod on the lateral loading actuation cylinder can pass through the round hole.

[0015] The beneficial effects of this solution are as follows: Since the connecting plate is located between the two pin seats and the two ends of the connecting plate are hinged to the pin seats, the lateral loading actuation cylinder is installed on the moving slide through the vertical connecting unit. The axial degree of freedom and the horizontal rotation direction degree of freedom of the lateral loading actuation cylinder are reserved, ensuring that the actuation cylinder can move freely along the piston rod direction under loading conditions without being interfered by forces in other directions, thus compensating for installation errors and machining errors.

[0016] Furthermore, it also includes a fixing unit, which includes a fixing seat with a connecting hole. The connecting hole is coaxially arranged with the piston rod of the hydraulic cylinder being tested for hydrostatic pressure.

[0017] The beneficial effects of this solution are as follows: Due to the installation of the fixed base, the internal leakage of the tested hydrostatic actuated cylinder under rated pressure can be detected, as well as the internal leakage of the tested hydrostatic actuated cylinder under rated pressure when subjected to lateral pressure. Specifically, when the tested hydrostatic actuated cylinder reaches its rated pressure, the piston rod of the tested hydrostatic actuated cylinder is fixed on the fixed base. At this time, the flow rate change in the low-pressure area of ​​the tested hydrostatic actuated cylinder is detected using a flow meter to determine the internal leakage of the tested hydrostatic actuated cylinder under rated pressure. Lateral pressure is applied to the tested hydrostatic actuated cylinder by a lateral loading actuated cylinder. At this time, the flow rate change in the low-pressure area of ​​the tested hydrostatic actuated cylinder can be detected using a flow meter to determine the internal leakage of the tested hydrostatic actuated cylinder under rated pressure when subjected to lateral pressure.

[0018] Furthermore, the horizontal connection unit includes a connecting seat, the piston rod of the lateral loading actuation cylinder is rotatably connected to the connecting seat, a connecting rod is welded on the connecting seat, a force sensor is sleeved on the connecting rod and fixed on the connecting seat, an L-shaped connecting strip is fixed on the connecting rod, and the piston rod of the hydrostatic pressure actuation cylinder being measured is fixed on the other side of the L-shaped connecting strip.

[0019] The beneficial effects of this solution are as follows: by connecting the piston rod of the hydrostatic actuating cylinder under test with the piston rod of the lateral loading actuating cylinder through the L-shaped connecting strip, the piston rod of the hydrostatic actuating cylinder under test and the piston rod of the lateral loading actuating cylinder are perpendicular to each other, thereby improving the reliability of the test.

[0020] Furthermore, a second displacement sensor is fixedly connected to the mounting base.

[0021] The beneficial effect of this solution is that the second displacement sensor can be used to calibrate the accuracy of the first displacement sensor.

[0022] Furthermore, a support frame is provided between the specimen installation unit and the fixing unit, and a third displacement sensor is fixed on the support frame.

[0023] The beneficial effects of this scheme are as follows: a constant lateral pressure is applied to the piston rod of the hydrostatic actuated cylinder under test by a lateral loading actuated cylinder, and the lateral displacement of the piston rod of the hydrostatic actuated cylinder under test under this lateral pressure is detected by a third displacement sensor. The stiffness of the piston rod of the hydrostatic actuated cylinder under test under this lateral pressure is determined by calculation. This index can be used to determine the stiffness of the hydrostatic actuated cylinder under test. Attached Figure Description

[0024] Figure 1 A three-dimensional diagram of a performance and reliability test bench for hydrostatically actuated hydraulic cylinders;

[0025] Figure 2 Three-dimensional diagrams of the specimen installation unit, linear movement unit, and lateral loading mechanism. Detailed Implementation

[0026] The following detailed description illustrates the specific implementation method:

[0027] The reference numerals in the accompanying drawings include: worktable 1, mounting base 2, hydraulic cylinder for measuring static pressure 3, fixed frame 4, movable slide 5, upper guide rail 6, lower guide rail 7, slider 8, lateral loading hydraulic cylinder 9, pin seat 10, connecting plate 11, rectangular hole 12, connecting seat 13, rotating shaft 14, force sensor 15, L-shaped connecting strip 16, fixed seat 17, second displacement sensor 18, support frame 19, third displacement sensor 20, and connecting rod 21.

[0028] Example

[0029] like Figure 1 The table shown is a performance and reliability test bench for hydrostatically actuated hydraulic cylinders, including a workbench 1, a specimen mounting unit, a moving unit, a fixing unit, and a lateral loading mechanism.

[0030] like Figure 1 As shown, the specimen installation unit includes a mounting base 2, a hydrostatic pressure actuation cylinder 3 under test, and a transition flange. The mounting base 2 is bolted onto the workbench 1 and has mounting holes. The hydrostatic pressure actuation cylinder 3 under test is mounted on the mounting base 2 via the transition flange. The piston rod of the hydrostatic pressure actuation cylinder 3 under test passes through the transition flange and is located on the right side of the mounting base 2. The piston rod of the hydrostatic pressure actuation cylinder 3 under test does not contact the transition flange. The hydrostatic pressure actuation cylinder 3 under test has a built-in first displacement sensor. Pressure acquisition points are provided at both ends of the hydrostatic pressure actuation cylinder 3 under test, and an external pressure sensor is connected to each pressure acquisition point. An external leakage detection connector is provided at the bottom of the hydrostatic pressure actuation cylinder 3 under test.

[0031] like Figure 2 As shown, the moving unit is located to the right of the specimen mounting unit. The moving unit includes a fixed frame 4 and a moving slide 5. The fixed frame 4 is bolted to the workbench 1, and the length of the fixed frame 4 is parallel to the piston rod of the hydrostatic cylinder 3 being measured. An upper guide rail 6 and a lower guide rail 7 are bolted to the left side of the fixed frame 4. Specifically, the upper guide rail 6 is bolted to the upper side of the fixed frame 4, and the lower guide rail 7 is bolted to the lower side of the fixed frame 4. Four sliders 8 are welded to the right side of the moving slide 5. Two sliders 8 are welded to the upper side of the moving slide 5, and the other two sliders 8 are welded to the lower side of the moving slide 5. The sliders 8 on the upper side of the moving slide 5 are slidably mounted on the upper guide rail 6, and the sliders 8 on the lower side of the moving slide 5 are slidably mounted on the lower guide rail 7.

[0032] like Figure 2 As shown, the lateral loading mechanism includes a lateral loading actuation cylinder 9, a flange, a vertical connection unit, and a horizontal connection unit.

[0033] like Figure 2 As shown, the vertical connecting unit is located on the right side of the movable slide 5, between the upper guide rail 6 and the lower guide rail 7. The vertical connecting unit includes a pin seat 10 and a connecting plate 11. There are two pin seats 10, which are welded to the upper and lower sides of the movable slide 5 respectively. The upper and lower ends of the connecting plate 11 are hinged to the pin seats 10, and the connecting plate 11 can swing back and forth. A round hole is opened in the middle of the connecting plate 11. A rectangular hole 12 is opened on the movable slide 5 between the two pin seats 10. The lateral loading actuation cylinder 9 is mounted on the connecting plate 11 through a flange. The piston rod of the lateral loading actuation cylinder 9 passes through the round hole and the rectangular hole 12 in sequence, and is located on the left side of the movable slide 5. The piston rod of the lateral loading actuation cylinder 9 does not contact the round hole and the rectangular hole 12.

[0034] like Figure 2 As shown, the horizontal connecting unit is located on the left side of the movable slide table 5. The horizontal connecting unit includes a connecting seat 13, on which a rotating shaft 14 is welded. The piston rod of the lateral loading actuation cylinder 9 is rotatably connected to the rotating shaft 14. A connecting rod 21 is welded to the left side of the connecting seat 13. A force sensor 15 is sleeved on the connecting rod 21. The force sensor 15 is fixed to the connecting seat 13 by bolts. An L-shaped connecting strip 16 is welded to the left side of the connecting rod 21. The piston rod of the measured static pressure actuation cylinder 3 is connected to the other side of the L-shaped connecting strip 16 by bolts, so that the piston rod of the measured static pressure actuation cylinder 3 and the piston rod of the lateral loading actuation cylinder 9 are perpendicular to each other.

[0035] like Figure 1 As shown, the fixing unit is located to the right of the specimen mounting unit. The fixing unit includes a fixing base 17, which is mounted on the workbench 1 by bolts. A second displacement sensor 18 is fixed to the fixing base 17 by bolts. The second displacement sensor 18 is used to calibrate the first displacement sensor. The fixing base 17 has a connecting hole, which is coaxially arranged with the piston rod of the hydrostatic cylinder 3 being measured.

[0036] like Figure 1 As shown, a support frame 19 is provided between the specimen installation unit and the fixing unit. The support frame 19 is fixed to the workbench 1 by bolts. A third displacement sensor 20 is fixed to the support frame 19 by bolts. The third displacement sensor 20 is used to detect the lateral displacement of the piston rod of the hydrostatic actuated cylinder 3 under test.

[0037] The specific implementation process is as follows:

[0038] 1. Testing of the friction and durability of the hydrostatically actuated cylinder 3 under test.

[0039] Due to the pressure sensor, when testing the friction performance of the hydrostatic actuated cylinder 3, a constant lateral pressure is applied to the piston rod of the hydrostatic actuated cylinder 3 via the lateral loading actuated cylinder 9, activating the hydrostatic actuated cylinder 3. The piston rod of the hydrostatic actuated cylinder 3 then reciprocates. Since the hydrostatic actuated cylinder 3 can drive the lateral loading actuated cylinder 9 to move synchronously via the moving unit, the lateral loading actuated cylinder 9 can apply real-time hydrostatic pressure to the hydrostatic cylinder. A constant lateral pressure is applied to the piston rod of the hydraulic cylinder 3. The pressure at both ends of the hydraulic cylinder 3 is detected by a pressure sensor. The pressure difference between the two ends of the hydraulic cylinder 3 is calculated. The friction performance of the hydraulic cylinder 3 is characterized by the pressure difference between the two ends of the hydraulic cylinder 3. At the same time, the durability of the hydraulic cylinder 3 is judged by detecting the number of reciprocating loads that the piston rod of the hydraulic cylinder 3 can withstand under constant lateral pressure.

[0040] 2. Load-bearing capacity test of the hydrostatic actuated cylinder 3 under test

[0041] When testing the load-bearing capacity of the hydrostatic actuated cylinder 3, the piston rod of the hydrostatic actuated cylinder 3 is extended to a fixed length. Lateral pressure is applied to the piston rod of the hydrostatic actuated cylinder 3 by the lateral loading actuated cylinder 9, and the lateral pressure is continuously increased. When the pressure of the hydrostatic actuated cylinder 3 does not change, the lateral pressure borne by the hydrostatic actuated cylinder 3 is the maximum load-bearing capacity of the hydrostatic actuated cylinder. The maximum load-bearing capacity of the hydrostatic actuated cylinder can be detected by the force sensor 15.

[0042] 3. Uniformity test of the hydrostatic actuated cylinder 3 under test

[0043] When testing the uniformity of the hydrostatic actuated cylinder 3, a constant lateral pressure is applied to the piston rod of the hydrostatic actuated cylinder 3 by the lateral loading actuated cylinder 9. Under the action of the constant lateral pressure, the hydrostatic actuated cylinder 3 is started, and the piston rod of the hydrostatic actuated cylinder 3 reciprocates. Since the stroke of the hydrostatic actuated cylinder 3 is relatively long, when the gap between the hydrostatic actuated cylinder 3 and the piston rod of the hydrostatic actuated cylinder 3 is not uniform, the lateral pressure applied in different stroke segments is unbalanced. The uniformity of the stroke of the hydrostatic actuated cylinder 3 is detected by the magnitude of the fluctuation of the applied lateral pressure. When the stroke of the hydrostatic actuated cylinder 3 is not uniform, it may be due to problems in the processing or assembly of the hydrostatic actuated cylinder 3.

[0044] 4. Internal leakage detection of the tested hydrostatic actuated cylinder 3 under rated pressure.

[0045] Due to the installation of the fixed base 17, the internal leakage of the tested static pressure actuated cylinder 3 under rated pressure can be detected, as well as the internal leakage of the tested static pressure actuated cylinder 3 under rated pressure when subjected to lateral pressure. Specifically, when the tested static pressure actuated cylinder 3 reaches the rated pressure, the piston rod of the tested static pressure actuated cylinder 3 is fixed on the fixed base 17. At this time, the flow rate change in the low-pressure area of ​​the tested static pressure actuated cylinder 3 is detected by using a flow meter to determine the internal leakage of the tested static pressure actuated cylinder 3 under rated pressure. Lateral pressure is applied to the tested static pressure actuated cylinder 3 by the lateral loading actuated cylinder 9. At this time, the flow rate change in the low-pressure area of ​​the tested static pressure actuated cylinder 3 can be detected by using a flow meter to determine the internal leakage of the tested static pressure actuated cylinder 3 under rated pressure when subjected to lateral pressure.

[0046] 5. Stiffness test of the hydrostatic actuated cylinder 3 under test

[0047] A constant lateral pressure is applied to the piston rod of the hydrostatic actuated cylinder 3 by the lateral loading actuated cylinder 9. The lateral displacement of the piston rod of the hydrostatic actuated cylinder 3 under the lateral pressure is detected by the third displacement sensor 20. The stiffness of the piston rod of the hydrostatic actuated cylinder 3 under the lateral pressure is determined by calculation. This index can be used to determine the stiffness of the hydrostatic actuated cylinder 3.

[0048] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A performance and reliability test bench for hydrostatically actuated hydraulic cylinders, characterized in that: The device includes a mounting base, a hydraulic cylinder for measuring static pressure, a moving unit, and a lateral loading mechanism. The hydraulic cylinder for measuring static pressure has pressure acquisition points at both ends, and pressure sensors are externally connected to the pressure acquisition points. The hydraulic cylinder for measuring static pressure has a built-in first displacement sensor. The hydraulic cylinder for measuring static pressure is fixedly mounted on the mounting base. The lateral loading mechanism is fixed on the moving unit, and a force sensor is fixed on the lateral loading mechanism. The lateral loading mechanism is connected to the piston rod of the hydraulic cylinder for measuring static pressure, and the lateral loading mechanism and the piston rod of the hydraulic cylinder for measuring static pressure are perpendicular to each other. The hydraulic cylinder for measuring static pressure can drive the lateral loading mechanism to move synchronously through the moving unit. The moving unit includes a fixed frame and a moving slide. The length of the fixed frame is parallel to the actuating cylinder of the hydrostatic pressure being measured. A guide rail is fixed on the fixed frame, and a slider is fixed on the moving slide. The slider is slidably mounted on the guide rail. The lateral loading mechanism includes a lateral loading actuation cylinder, a vertical connecting unit, and a horizontal connecting unit. The piston rod of the lateral loading actuation cylinder is hinged to the horizontal connecting unit, and the lateral loading actuation cylinder is fixed on the vertical connecting unit. The vertical connection unit includes a pin seat and a connecting plate. There are two pin seats, which are fixed on the upper and lower sides of the movable slide respectively. The connecting plate is located between the two pin seats, and both ends of the connecting plate are hinged to the pin seats. The connecting plate can swing back and forth. The connecting plate has a round hole. The lateral loading actuation cylinder is fixed on the connecting plate, and the piston rod on the lateral loading actuation cylinder can pass through the round hole.

2. The performance and reliability test bench for hydrostatically actuated hydraulic cylinders according to claim 1, characterized in that: The horizontal connection unit includes a connecting seat, the piston rod of the lateral loading actuation cylinder is rotatably connected to the connecting seat, a connecting rod is welded on the connecting seat, a force sensor is sleeved on the connecting rod and fixed on the connecting seat, an L-shaped connecting strip is fixed on the connecting rod, and the piston rod of the hydrostatic pressure actuation cylinder being measured is fixed on the other side of the L-shaped connecting strip.

3. The performance and reliability test bench for hydrostatically actuated hydraulic cylinders according to claim 2, characterized in that: It also includes a fixing unit, which includes a fixing base with a connecting hole. The connecting hole is coaxially arranged with the piston rod of the hydrostatic actuation cylinder being measured.

4. The performance and reliability test bench for hydrostatically actuated hydraulic cylinders according to claim 3, characterized in that: A second displacement sensor is fixedly connected to the fixed base.

5. A performance and reliability test bench for hydrostatically actuated hydraulic cylinders according to claim 4, characterized in that: A support frame is provided between the specimen installation unit and the fixing unit, and a third displacement sensor is fixed on the support frame.

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