Performance testing method of high-load large-stroke air spring assembly

Abstract

This invention relates to a performance testing method for a high-load-bearing, long-stroke air spring assembly, comprising the following steps: S1, determining the model and operating parameters; S2, installation and alignment; S3, air pressure setting; S4, pre-cycle; S5, stretching the air spring; S6, compressing the air spring; S7, unloading and returning; S8, recording deformation data. Before formally recording data, the performance testing method of this invention performs multiple complete compression and rebound pre-cycles on the air spring. This not only eliminates the initial structural stress relaxation of the air spring bladder and cord layer, improving the repeatability and consistency of stiffness testing, but also identifies hidden damage or assembly defects in the air bladder in advance, avoiding sudden failure during formal testing. Furthermore, it allows the rubber material of the air spring to reach a stable hysteresis working state, simulating the actual pre-service break-in process, making the subsequently measured stiffness parameters closer to the true values ​​of long-term stable operation, and thus making the test data more accurate.

Description

Technical Field

[0001] This invention relates to the field of air spring technology, and in particular to a performance testing method for a high-load, long-stroke air spring assembly. Background Technology

[0002] An air spring is a spring that utilizes the elasticity of air within a retractable, sealed container. Compared to metal springs, it offers advantages such as smaller weight, better comfort, fatigue resistance, and longer service life. It also boasts superior vibration damping, adjustable stiffness, and high load-bearing capacity. Therefore, air springs are widely used in automobiles and industrial equipment. The stiffness of an air spring is a crucial parameter characterizing its performance, directly reflecting its ability to withstand forces under static conditions. The main factors affecting the static stiffness of an air spring are displacement, load, and internal pressure. Under certain deformation conditions, a higher static stiffness value translates to a greater load-bearing capacity. Before deployment, air springs must undergo product characteristic testing to ensure their quality.

[0003] Currently, the air spring stiffness testing methods still have some shortcomings for high-load, long-stroke air springs: they do not consider nonlinearity under large displacement, the outer diameter testing method is rough, and there is no unloading return stroke, which affects the testing accuracy.

[0004] Therefore, this invention proposes a performance testing method for high-load, long-stroke air spring assemblies to solve the above problems. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a performance testing method for high load-bearing, long-stroke air spring assemblies, thereby improving the stiffness testing accuracy of high load-bearing, long-stroke air spring assemblies.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is: a performance testing method for a high-load-bearing, long-stroke air spring assembly, the innovation of which lies in the following steps: S1. Determine the model and operating parameters: Determine and record the air spring's model, number of bends, rated height H0, and maximum tensile height H. max Minimum compression height H min Within the range of rated load N and rated air pressure P, measure and record the initial outer diameter and initial internal pressure; S2. Installation and Alignment: Fix the lower end of the air spring to the lower frame of the electro-hydraulic servo fatigue testing machine. Connect the upper end of the air spring to a high-precision load sensor. Use a laser alignment instrument to adjust the coaxiality of the air spring to ensure that the coaxiality deviation is ≤0.5 mm. Apply an initial preload of 50~100N to the air spring from the upper frame of the electro-hydraulic servo fatigue testing machine to make the contact tight. Record the height of the air spring at this time as the installation height. S3. Air pressure setting: Set the first air pressure value, the second air pressure value and the third air pressure value according to the model of the air spring. Inflate the air spring in sequence to the first air pressure value, the second air pressure value and the third air pressure value. After each inflation, let it stand still for 5 minutes to confirm that there is no leakage. S4. Pre-cycle: Perform 3 to 5 compression-springback pre-cycles at a speed of 20 mm / min within the available stroke range; S5. Extending the air spring: Starting from the rated height H0, extend the air spring upwards at a speed of 10~30 mm / min to 0.9H. max During the stretching process, the displacement, load, and internal pressure data of the air spring are continuously collected. S6. Compressed Air Spring: Starting from the rated height H0, compress the air spring upwards and downwards at a speed of 10~30 mm / min until it reaches 1.1H. min During the compression process, the displacement, load, and internal pressure data of the air spring are continuously collected. S7. Unloading and Return: After compression is completed, the air spring returns to the rated height H0 at the same speed as the compression speed, and the displacement, load and internal pressure data of the air spring are continuously collected. S8. Record deformation data: Use a 3D laser profilometer to measure the outer diameter of the air spring and calculate the static stiffness, ultimate stiffness, residual deformation and volumetric stiffness coefficient.

[0007] Furthermore, in step S3, the first air pressure value is 0.2 MPa, the second air pressure value is the rated air pressure P, and the third air pressure value is 0.2 P.

[0008] Furthermore, the available travel range in step S4 is 0.2H. min ~0.8H max .

[0009] Furthermore, in step S6, if the load on the air spring drops by more than 20% of the current value during compression, the airbag becomes unstable, immediately triggering an emergency stop and unloading, and the height and load at the time of instability are recorded.

[0010] Furthermore, in step S6, during the compression process, the pressure is maintained for 5 minutes at the positions of 25% compression stroke, 50% compression stroke, and 75% compression stroke, respectively, and the pressure attenuation beam and load attenuation are recorded during the pressure maintenance.

[0011] Furthermore, the compression stroke is the rated height H0 and 1.1H. min The difference.

[0012] The advantages of this invention are: The performance testing method of this invention performs multiple complete compression and rebound pre-cycles on the air spring before formally recording data. This not only eliminates the initial structural stress relaxation of the air spring airbag and cord layer, improving the repeatability and consistency of stiffness testing, but also identifies hidden damage or assembly defects in the airbag in advance, avoiding sudden failure during formal testing. In addition, it enables the rubber material of the air spring to reach a stable hysteresis working state, simulating the actual pre-service break-in process, making the subsequently measured stiffness parameters closer to the true values ​​of long-term stable operation, and making the test data more accurate.

[0013] The performance testing method of this invention adopts continuous acquisition to fully record the force and displacement curves from the linear region to the hardened region to the ultimate bottoming-out region. Furthermore, the large stroke is clearly divided into different stiffness intervals for separate calculation and analysis, accurately capturing the nonlinear stiffness mutation and ultimate bottoming-out behavior under the large stroke, and providing a quantitative basis for judging whether a high-load, large-stroke air spring will experience bottoming-out failure. Detailed Implementation

[0014] To further illustrate the technical means and effects of the present invention in achieving the intended purpose, the following detailed description of the specific implementation methods, structures, features and effects of the present invention, in conjunction with preferred embodiments, is provided below.

[0015] Example This embodiment provides a performance testing method for a high-load-bearing, long-stroke air spring assembly, including the following steps: S1. Determine the model and operating parameters: Determine and record the air spring's model, number of bends, rated height H0, and maximum tensile height H. max Minimum compression height H min Within the range of rated load N and rated air pressure P, measure and record the initial outer diameter and initial internal pressure; S2. Installation and Alignment: Fix the lower end of the air spring to the lower frame of the electro-hydraulic servo fatigue testing machine. Connect the upper end of the air spring to a high-precision load sensor. Use a laser alignment instrument to adjust the coaxiality of the air spring to ensure that the coaxiality deviation is ≤0.5 mm. Apply an initial preload of 50~100N to the air spring from the upper frame of the electro-hydraulic servo fatigue testing machine to make the contact tight. Record the height of the air spring at this time as the installation height. S3. Air pressure setting: Set the first air pressure value to 0.2MPa, the second air pressure value to P, and the third air pressure value to 0.2P according to the model of the air spring. Inflate the air spring in sequence to the first air pressure value, the second air pressure value, and the third air pressure value. After each inflation, let it stand for 5 minutes to maintain the pressure and confirm that there is no leakage. S4, Pre-circulation: At a speed of 20 mm / min, within the available stroke of 0.2H min ~0.8H maxPerform 3-5 compression-springback pre-cycles within the specified range; S5. Extending the air spring: Starting from the rated height H0, extend the air spring upwards at a speed of 20mm / min to 0.9H. max During the stretching process, the displacement, load, and internal pressure data of the air spring are continuously collected. S6, Compressed Air Spring: Starting from the rated height H0, compress the air spring upwards and downwards at a speed of 20 mm / min to 1.1H. min During compression, the displacement, load, and internal pressure data of the air spring are continuously collected. If the load of the air spring drops by more than 20% of the current value during compression, the airbag becomes unstable, immediately triggering an emergency stop and unloading. The height and load at the time of instability are recorded. During compression, the pressure was held for 5 minutes at 25%, 50%, and 75% of the compression stroke, respectively. The pressure decay beam and load decay were recorded during these holding periods. The compression stroke was defined as the rated height H0 and 1.1H. min The difference.

[0016] S7. Unloading and Return: After compression is completed, the air spring returns to the rated height H0 at the same speed as the compression speed, and the displacement, load and internal pressure data of the air spring are continuously collected. S8. Record deformation data: Use a 3D laser profilometer to measure the outer diameter of the air spring and calculate the static stiffness, ultimate stiffness, residual deformation and volumetric stiffness coefficient.

[0017] Before formally recording data, the performance testing method involves subjecting the air spring to multiple complete compression and rebound pre-cycles. This not only eliminates the initial structural stress relaxation of the air spring bladder and cord layer, improving the repeatability and consistency of stiffness testing, but also identifies hidden damage or assembly defects in the air bladder in advance, preventing sudden failure during formal testing. Furthermore, it allows the rubber material of the air spring to reach a stable hysteresis working state, simulating the actual pre-service break-in process, making the subsequently measured stiffness parameters closer to the true values ​​of long-term stable operation, and thus making the test data more accurate.

[0018] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A performance testing method for a high-load-bearing, long-stroke air spring assembly, characterized in that: Includes the following steps: S1. Determine the model and operating parameters: Determine and record the air spring's model, number of bends, rated height H0, and maximum tensile height H. max Minimum compression height H min Within the range of rated load N and rated air pressure P, measure and record the initial outer diameter and initial internal pressure; S2. Installation and Alignment: Fix the lower end of the air spring to the lower frame of the electro-hydraulic servo fatigue testing machine. Connect the upper end of the air spring to a high-precision load sensor. Use a laser alignment instrument to adjust the coaxiality of the air spring to ensure that the coaxiality deviation is ≤0.5mm. Apply an initial preload of 50~100N to the air spring from the upper frame of the electro-hydraulic servo fatigue testing machine to make the contact tight. Record the height of the air spring at this time as the installation height. S3. Air pressure setting: Set the first air pressure value, the second air pressure value and the third air pressure value according to the model of the air spring. Inflate the air spring in sequence to the first air pressure value, the second air pressure value and the third air pressure value. After each inflation, let it stand still for 5 minutes to confirm that there is no leakage. S4. Pre-cycle: Perform 3 to 5 compression-springback pre-cycles at a speed of 20 mm / min within the available stroke range; S5. Extending the air spring: Starting from the rated height H0, extend the air spring upwards at a speed of 10~30 mm / min to 0.9H. max During the stretching process, the displacement, load, and internal pressure data of the air spring are continuously collected. S6. Compressed Air Spring: Starting from the rated height H0, compress the air spring upwards and downwards at a speed of 10~30 mm / min until it reaches 1.1H. min During the compression process, the displacement, load, and internal pressure data of the air spring are continuously collected. S7. Unloading and Return: After compression is completed, the air spring returns to the rated height H0 at the same speed as the compression speed, and the displacement, load and internal pressure data of the air spring are continuously collected. S8. Record deformation data: Use a 3D laser profilometer to measure the outer diameter of the air spring and calculate the static stiffness, ultimate stiffness, residual deformation and volumetric stiffness coefficient.

2. The performance testing method for the high-load-bearing, long-stroke air spring assembly according to claim 1, characterized in that: In step S3, the first air pressure value is 0.2 MPa, the second air pressure value is the rated air pressure P, and the third air pressure value is 0.2 P.

3. The performance testing method for the high-load-bearing, long-stroke air spring assembly according to claim 1, characterized in that: The available travel range in step S4 is 0.2H. min ~0.8H max .

4. The performance testing method for the high-load-bearing, long-stroke air spring assembly according to claim 1, characterized in that: In step S6, if the load on the air spring drops by more than 20% of the current value during compression, the airbag becomes unstable, immediately triggering an emergency stop and unloading. The height and load at the time of instability are recorded.

5. The performance testing method for the high-load-bearing, long-stroke air spring assembly according to claim 1, characterized in that: In step S6, during the compression process, the pressure is maintained for 5 minutes at the positions of 25% compression stroke, 50% compression stroke, and 75% compression stroke, respectively. During the pressure maintenance, the pressure attenuation beam and the load attenuation are recorded.

6. The performance testing method for the high-load-bearing, long-stroke air spring assembly according to claim 5, characterized in that: The compression stroke is between the rated height H0 and 1.1H. min The difference.