Device for testing friction force between piston rod of shock absorber and guider

Abstract

The utility model discloses a device for testing the friction force between a piston rod and a guider of a shock absorber, which comprises a shock absorber cylinder barrel, a piston assembly, a guider, a floating piston, a fixed barrel, a connecting nut and a data acquisition system, and is characterized in that the shock absorber cylinder barrel is used for storing a liquid medium and simulating the internal environment of the shock absorber; the piston assembly comprises a piston rod and can reciprocate along the shock absorber cylinder barrel, the guiders are fixed to the two ends of the shock absorber cylinder barrel to guide and seal the piston rod, the floating piston adjusts the pressure in the shock absorber cylinder barrel through the inflation system, the fixed barrel is matched with the movement range of the piston rod, and the connecting nut is used for being connected with external testing equipment. The data acquisition system monitors displacement, speed and damping force parameters in real time, interference of other parts in the shock absorber is isolated through modular design, and independent testing of a piston rod and a guider friction pair is achieved. The shock absorber cylinder simulates the real working condition, the pressure environment can be dynamically adjusted through combination of the floating piston and the inflation system, and the problem that an existing pressure condition is single is solved.

Description

A device for testing the friction force between a shock absorber piston rod and a guide. Technical Field

[0001] This utility model relates to the field of automotive parts testing technology, and in particular to a friction force testing device for a shock absorber piston rod and guide. Background Technology

[0002] As is well known, automotive shock absorbers are a crucial component of vehicle suspension systems, and their friction performance directly affects vehicle comfort and the driving experience. Currently, most shock absorber friction tests can only measure the friction force of the internal assembly after inflation and lubrication. In actual use, the friction force of the shock absorber is affected by multiple components, among which the friction force between the guide and the piston rod is the key factor determining the overall friction force of the shock absorber assembly. To eliminate the influence of other factors on the friction force between the guide and the piston rod, a device is needed that can solely test the friction force between the piston rod and the guide. However, most existing friction testing devices have the following limitations:

[0003] 1. It can only test the friction force of the shock absorber assembly. The measured friction force value of the shock absorber is also affected by the interference of other internal components of the shock absorber. It cannot measure the friction force between the piston rod and the guide friction pair.

[0004] 2. Moreover, most tests on the friction force of shock absorbers are conducted under a constant pressure environment between the piston rod and the guide, making it impossible to measure the true friction force of the piston rod and guide friction pair under no pressure or various pressure environments. Summary of the Invention

[0005] The purpose of this invention is to provide a friction force testing device that can test the friction force of the piston rod and guide friction pair in an automotive shock absorber under adjustable pressure.

[0006] To achieve the above objectives, this utility model adopts the following technical solution: a friction force testing device for a shock absorber piston rod and a guide, comprising a shock absorber cylinder, a piston assembly, a guide, a floating piston, a fixed cylinder, a connecting nut, and a data acquisition system, characterized in that the shock absorber cylinder is used to store a liquid medium and simulate the internal environment of the shock absorber; the piston assembly includes a piston rod and is capable of reciprocating along the shock absorber cylinder; the guide is fixed at both ends of the shock absorber cylinder to provide guidance and sealing for the piston rod; the floating piston adjusts the pressure inside the shock absorber cylinder through an inflation system; the fixed cylinder is adapted to the piston rod's range of motion; the connecting nut is used to connect external testing equipment; and the data acquisition system monitors displacement, velocity, and damping force parameters in real time.

[0007] In one embodiment, the floating piston is connected to an external inflation system via a valve, and the inflation system can adjust the gas pressure to change the pressure environment of the liquid medium inside the shock absorber cylinder.

[0008] In one embodiment, the inflation system includes a pressure sensor and a proportional valve, and dynamically adjusts the pressure environment through closed-loop control.

[0009] In one embodiment, the data acquisition system includes a displacement sensor, a force sensor, and a host computer. The displacement sensor monitors the movement trajectory of the piston rod, the force sensor collects damping force data, and the host computer integrates data storage and visualization analysis functions.

[0010] In one embodiment, the length of the fixed cylinder is adjustable and can be adapted to piston rods of different lengths via threaded connections or snap-fit ​​structures.

[0011] In one embodiment, the connecting nut adopts a standard interface design to adapt to the connecting table of different brands of dynamometers or fatigue testing machines.

[0012] In one embodiment, the cylinder of the shock absorber is filled with magnetorheological fluid, and the viscosity of the fluid is controlled by an external magnetic field to simulate different damping characteristics.

[0013] In one embodiment, the inner surface of the guide is provided with a wear-resistant coating, the material of which is polytetrafluoroethylene or ceramic composite material.

[0014] In one embodiment, a temperature sensor is provided between the piston assembly and the guide to monitor the operating temperature of the friction pair in real time.

[0015] In one embodiment, the data acquisition system supports wireless transmission, and test data is remotely shared and analyzed through a cloud platform.

[0016] By adopting the above technical solution, this utility model has the following advantages:

[0017] 1. In this utility model, the modular design isolates interference from other internal components of the shock absorber, enabling independent testing of the piston rod and guide friction pair. The shock absorber cylinder simulates real working conditions, and the combination of the floating piston and the air charging system allows for dynamic adjustment of the pressure environment, solving the problem of single pressure conditions in existing technologies. The adaptability design of the connecting nut makes the device compatible with commercially available indicator machines or fatigue testing machines, while the data acquisition system improves the comprehensiveness and accuracy of the test through multi-parameter monitoring, providing a reliable basis for subsequent optimization of the friction pair structure.

[0018] 2. By linking the inflation system with the floating piston, this solution achieves precise control of the internal pressure of the shock absorber cylinder. The inflation system adjusts the gas pressure to drive the floating piston, thereby changing the pressure distribution of the liquid medium and simulating the pressure environment under different shock absorber operating conditions. This design breaks through the limitation of fixed pressure in traditional devices, enabling the testing of the friction characteristics of the piston rod and guide friction pair under various operating conditions such as high pressure, low pressure, or no pressure, providing a technical basis for the dynamic performance evaluation of the friction pair.

[0019] 3. A pressure sensor monitors the gas pressure inside the shock absorber cylinder in real time. A proportional valve dynamically adjusts the gas flow rate based on the difference between the set and actual values, forming a closed-loop control. This technology solves the problems of low accuracy and slow response caused by manual pressure adjustment, ensuring the stability and repeatability of the pressure environment during testing. The closed-loop control mechanism significantly improves the reliability of test data, and is particularly suitable for simulating complex operating conditions requiring continuously changing pressure, such as the dynamic response testing of vehicle shock absorbers on bumpy roads.

[0020] 4. Through the collaborative operation of multiple sensors, this solution achieves comprehensive monitoring of the dynamic characteristics of the friction pair. Displacement sensors accurately record the piston rod's trajectory, force sensors capture changes in frictional force, and the host computer integrates the data using algorithms to generate a visual report. This technology solves the problem that traditional testing devices can only output a single force value, enabling analysis of the frictional behavior of the friction pair under different speeds and displacements, providing multi-dimensional data support for optimizing guide structure (such as groove design and material selection).

[0021] 5. The adjustable design of the fixed cylinder allows the device to adapt to different models of piston rods, expanding the versatility of the testing device. The length of the fixed cylinder can be quickly adjusted via a threaded or snap-fit ​​structure, ensuring compatibility with both short-stroke and long-stroke shock absorbers without replacing core components. This technology solves the problem of limited testing range caused by the fixed size of existing devices, reducing the procurement costs of testing equipment for different vehicle models and improving the device's economy and practicality.

[0022] 6. The standardized connection interface design allows this device to quickly interface with mainstream testing equipment on the market without additional modifications. By using a unified interface specification, the problem of poor compatibility between traditional testing devices and external equipment is solved, simplifying the testing process and shortening equipment debugging time. Furthermore, the standardized design reduces user dependence on specific brand equipment, enhancing the device's flexibility and market competitiveness.

[0023] 7. By introducing magnetorheological fluid, this scheme expands the testing capabilities of the device. The external magnetic field can dynamically adjust the fluid viscosity, simulating the operating conditions of the shock absorber under different damping modes (such as sport mode and comfort mode). This technology overcomes the limitations of traditional oil media, enabling the testing device to evaluate the adaptability of friction pairs in variable damping environments, and providing an experimental platform for the research and development of intelligent shock absorbers.

[0024] 8. By applying a wear-resistant coating, frictional wear between the guide and the piston rod is significantly reduced, extending the device's service life. PTFE or ceramic composite materials possess a low coefficient of friction and high corrosion resistance, ensuring that the performance of the friction pair is unaffected by coating degradation during testing. Furthermore, the coating design can simulate the surface treatment process of the guide in actual vibration dampers, making the test results closer to real-world conditions and enhancing the engineering guidance value of the data.

[0025] 9. By integrating the temperature sensor, the potential temperature rise problem of friction pairs under high-speed operation is solved. Real-time monitoring of the operating temperature allows analysis of the correlation between friction force and temperature, avoiding test errors or equipment damage caused by overheating. This technology is particularly suitable for evaluating the stability of friction pairs under extreme conditions (such as continuous high-frequency vibration), providing data support for improving the heat resistance of materials.

[0026] 10. The combination of wireless transmission and a cloud platform enables real-time sharing and remote collaborative analysis of test data. Users can view test progress and results anytime via mobile devices or computers, improving R&D efficiency. Furthermore, cloud storage avoids the risk of local data loss, supports big data accumulation and machine learning analysis, and provides a technical foundation for long-term performance prediction and optimization of friction pairs. Attached Figure Description

[0027] The present invention will be further described below with reference to the accompanying drawings:

[0028] Figure 1 is a schematic diagram of the friction force testing device of this utility model.

[0029] Figure 2 is a side view of the friction force testing device of this utility model.

[0030] Figure 3 is a cross-sectional view along the AA direction in Figure 2.

[0031] Figure 4 is a wireframe diagram of the data acquisition system described in this utility model.

[0032] The names of the components shown in the diagram are as follows:

[0033] 1. Shock absorber cylinder; 11. Magnetorheological fluid; 2. Piston assembly; 21. Piston rod; 3. Guide; 31. Guide fixed end cap; 32. Wear-resistant coating; 4. Floating piston; 41. Floating piston cylinder; 42. Floating piston cylinder end cap; 43. Inflation chamber; 44. Magnetorheological fluid chamber; 5. Fixed cylinder; 51. Air chamber body; 6. Connecting nut; 7. Data acquisition system; 71. Displacement sensor; 72. Force sensor; 73. Host computer; 8. Air nozzle; 9. Temperature sensor. Detailed Implementation

[0034] To more clearly illustrate the overall concept of this utility model, a detailed description will be provided below with reference to the accompanying drawings.

[0035] It should be noted that many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0036] Furthermore, it should be understood in the description of this utility model that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0037] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral unit; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. However, specifying a direct connection indicates that the two main bodies at the connection point are not connected by an intermediate structure, but are simply connected to form a whole through a connecting structure. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0038] In this utility model, unless otherwise expressly specified and limited, the first feature "on" or "below" the second feature may be in direct contact with the first and second features, or indirect contact through an intermediate medium. In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0039] As shown in Figures 1 to 4, this utility model provides a friction force testing device for a shock absorber piston rod and guide, including a shock absorber cylinder 1, a piston assembly 2, a guide 3, a floating piston 4, a fixed cylinder 5, a connecting nut 6, and a data acquisition system 7. The shock absorber cylinder 1 stores a liquid medium and simulates the internal environment of the shock absorber. The piston assembly 2 includes a piston rod 21 and can reciprocate along the shock absorber cylinder 1. The guide 3 is fixed to both ends of the shock absorber cylinder 1 to provide guidance and sealing for the piston rod 21. The floating piston 4 adjusts the internal pressure of the shock absorber cylinder 1 through an inflation system. The fixed cylinder 5 is adapted to the movement range of the piston rod 21 and has a gas chamber. The connecting nut 6 is used to connect external testing equipment. The data acquisition system 7 monitors displacement, velocity, and damping force parameters in real time. Through modular design, interference from other internal components of the shock absorber is isolated, enabling independent testing of the friction pair between the piston rod and the guide. The shock absorber cylinder simulates real working conditions, and the combination of the floating piston and the inflation system can dynamically adjust the pressure environment, solving the problem of single pressure conditions in the prior art. The adaptability design of the connecting nut makes the device compatible with commercially available dynamometers or fatigue testing machines, while the data acquisition system improves the comprehensiveness and accuracy of the test through multi-parameter monitoring, providing a reliable basis for subsequent optimization of the friction pair structure.

[0040] In some embodiments, the floating piston 4 includes a floating piston cylinder 41 and a floating piston cylinder end cap 42 disposed at the end of the floating piston cylinder 41. The inner cavity of the floating piston 41 is divided into an inflation chamber 43 and a magnetorheological fluid chamber 44. The inflation chamber 43 is connected to an external inflation system through an air nozzle 8. The inflation system can adjust the gas pressure to change the pressure environment of the liquid medium inside the damper cylinder 1. The liquid medium inside the damper cylinder 1 can be a magnetorheological fluid 11, or it can be oil. In this way, through the linkage between the inflation system and the floating piston, this embodiment achieves precise control of the internal pressure of the cylinder. The inflation system pushes the floating piston to move by adjusting the gas pressure, thereby changing the pressure distribution of the liquid medium and simulating the pressure environment under different working conditions of the damper. This design breaks through the limitation of fixed pressure in traditional devices and can test the friction characteristics of the piston rod and guide friction pair under various working conditions such as high pressure, low pressure, or no pressure, providing a technical basis for the dynamic performance evaluation of the friction pair.

[0041] In some embodiments, the inflation system includes a pressure sensor and a proportional valve, and dynamically adjusts the pressure environment through closed-loop control. The pressure sensor monitors the gas pressure inside the cylinder in real time, and the proportional valve dynamically adjusts the gas flow rate based on the difference between the set value and the actual value, forming a closed-loop control. This technology solves the problems of low accuracy and slow response caused by manual pressure adjustment, ensuring the stability and repeatability of the pressure environment during testing. The closed-loop control mechanism significantly improves the reliability of test data, and is particularly suitable for simulating complex operating conditions that require continuous pressure changes, such as the dynamic response testing of vehicle shock absorbers on bumpy roads.

[0042] In some embodiments, as shown in Figure 4, the data acquisition system 7 includes a displacement sensor 71, a force sensor 72, and a host computer 73. The displacement sensor 71 monitors the movement trajectory of the piston rod 21, the force sensor 72 collects damping force data, and the host computer 73 integrates data storage and visualization analysis functions. Through the collaborative work of multiple sensors, this solution achieves comprehensive monitoring of the dynamic characteristics of the friction pair. The displacement sensor accurately records the movement trajectory of the piston rod, the force sensor captures changes in friction force, and the host computer integrates the data through algorithms and generates a visualization report. This technology solves the problem that traditional testing devices can only output a single force value, and can analyze the friction behavior of the friction pair under different speeds and displacements, providing multi-dimensional data support for optimizing the guide structure (such as groove design and material selection).

[0043] In some embodiments, the length of the fixed cylinder 5 can be set to be adjustable. The fixed cylinder 5 includes a gas chamber 51 and can be adapted to piston rods of different lengths via threaded connections or snap-fit ​​structures. The adjustable design of the fixed cylinder allows the device to adapt to different models of piston rods, expanding the versatility of the testing device. The length of the fixed cylinder can be quickly adjusted via threaded or snap-fit ​​structures, ensuring compatibility with short-stroke or long-stroke shock absorbers without replacing core components. This technology solves the problem of limited testing range caused by fixed dimensions in existing devices, reduces the procurement cost of testing equipment for different vehicle models, and improves the economy and practicality of the device.

[0044] In some embodiments, the connecting nut 6 adopts a standard interface design to adapt to the connection tables of different brands of dynamometers or fatigue testing machines. This standardized interface design allows the device to quickly interface with mainstream testing equipment on the market without additional modifications. By unifying interface specifications, the problem of poor compatibility between traditional testing devices and external equipment is solved, simplifying the testing process and shortening equipment debugging time. Furthermore, the standardized design reduces users' dependence on specific brand equipment, enhancing the device's flexibility and market competitiveness.

[0045] In some embodiments, the cylinder 1 of the shock absorber is filled with magnetorheological fluid, and the viscosity of the fluid is controlled by an external magnetic field to simulate different damping characteristics. The introduction of magnetorheological fluid expands the testing capabilities of the device. The external magnetic field can dynamically adjust the fluid viscosity to simulate the operating conditions of the shock absorber under different damping modes (such as sport mode and comfort mode). This technology overcomes the limitations of traditional oil-based media, enabling the testing device to evaluate the adaptability of the friction pair under variable damping environments, and providing an experimental platform for the development of intelligent shock absorbers.

[0046] In some embodiments, the guide 3 may include a guide fixing end cap 31, and the inner surface of the guide 3 may be provided with a wear-resistant coating 32. The wear-resistant coating 32 is made of polytetrafluoroethylene (PTFE) or ceramic composite material. By providing a wear-resistant coating, the frictional wear between the guide and the piston rod is significantly reduced, extending the service life of the device. PTFE or ceramic composite material has a low coefficient of friction and high corrosion resistance, ensuring that the performance of the friction pair is not affected by coating degradation during testing. Furthermore, the coating design can simulate the surface treatment process of the guide in an actual vibration damper, making the test results closer to real working conditions and enhancing the engineering guidance value of the data.

[0047] In some embodiments, a temperature sensor 9 is provided between the piston assembly 2 and the guide 3 to monitor the operating temperature of the friction pair in real time. By integrating the temperature sensor, the problem of temperature rise that may occur in the friction pair under high-speed movement is solved. By monitoring the operating temperature in real time, the correlation between friction force and temperature can be analyzed, avoiding test errors or equipment damage caused by overheating. This technology is particularly suitable for evaluating the stability of the friction pair under extreme conditions (such as continuous high-frequency vibration), providing data support for improving the heat resistance of materials.

[0048] In some embodiments, the data acquisition system 7 supports wireless transmission, enabling remote sharing and analysis of test data via a cloud platform. This combination of wireless transmission and the cloud platform facilitates real-time sharing and remote collaborative analysis of test data. Users can view test progress and results anytime via mobile devices or computers, improving R&D efficiency. Furthermore, cloud storage avoids the risk of local data loss, supports big data accumulation and machine learning analysis, and provides a technical foundation for long-term performance prediction and optimization of friction pairs.

[0049] In addition to the preferred embodiments described above, the technical solutions protected by this utility model are not limited to the above embodiments. It should be noted that any combination of the technical solutions of any embodiment with one or more other embodiments is within the protection scope of this utility model. Although this utility model has been described in detail above with general descriptions and specific embodiments, some modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of this utility model are within the scope of protection claimed by this utility model.

Claims

1. A device for testing the friction force between a shock absorber piston rod and a guide, comprising a shock absorber cylinder, a piston assembly, a guide, a floating piston, a fixed cylinder, a connecting nut, and a data acquisition system, characterized in that, The damper cylinder is used to store liquid medium and simulate the internal environment of the damper. The piston assembly includes a piston rod and can reciprocate along the cylinder. The guide is fixed at both ends of the cylinder to provide guidance and sealing for the piston rod. The floating piston adjusts the pressure inside the cylinder through an inflation system. The fixed cylinder is adapted to the range of motion of the piston rod. The connecting nut is used to connect external testing equipment. The data acquisition system monitors displacement, velocity, and damping force parameters in real time.

2. The friction force testing device according to claim 1, characterized in that, The floating piston is connected to an external inflation system via a gas nozzle. The inflation system can adjust the gas pressure to change the pressure environment of the liquid medium inside the cylinder.

3. The friction force testing device according to claim 1, characterized in that, The inflation system includes a pressure sensor and a proportional valve, and achieves dynamic adjustment of the pressure environment through closed-loop control.

4. The friction force testing device according to claim 1, characterized in that, The data acquisition system includes a displacement sensor, a force sensor, and a host computer. The displacement sensor monitors the movement trajectory of the piston rod, the force sensor collects damping force data, and the host computer integrates data storage and visualization analysis functions.

5. The friction force testing device according to claim 1, characterized in that, The length of the fixed cylinder is adjustable and can be adapted to piston rods of different lengths via threaded connections or snap-fit ​​structures.

6. The friction force testing device according to claim 1, characterized in that, The connecting nut adopts a standard interface design to be compatible with the connecting table of different brands of indicator machines or fatigue testing machines.

7. The friction force testing device according to claim 1, characterized in that, The cylinder of the shock absorber is filled with magnetorheological fluid, and the viscosity of the fluid is controlled by an external magnetic field to simulate different damping characteristics.

8. The friction force testing device according to claim 1, characterized in that, The inner surface of the guide is provided with a wear-resistant coating, which is made of polytetrafluoroethylene or ceramic composite material.

9. The friction force testing device according to claim 1, characterized in that, A temperature sensor is installed between the piston assembly and the guide to monitor the operating temperature of the friction pair in real time.

10. The friction force testing device according to claim 1, characterized in that, The data acquisition system supports wireless transmission, and test data can be remotely shared and analyzed through a cloud platform.

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