Trailer axle structural strength testing device

Abstract

The invention relates to the technical field of vehicle testing, and discloses a trailer axle structural strength testing device, which comprises a gantry main force frame, two hydraulic parts, a first hydraulic part and a second hydraulic part, the axle covering mechanisms are symmetrically arranged on the two sides of the telescopic arm of the hydraulic part and comprise expansion air bags distributed in the circumferential direction and winding and unwinding rubber ropes linked with the expansion air bags, and the tail ends of the winding and unwinding rubber ropes are connected with the dynamic detection structure; the dynamic detection structure comprises a flexible rubber sleeve, a vertical attaching assembly and miniature strain gauges of a strain detection network, the miniature strain gauges are arranged on the lower surface of the flexible rubber sleeve in an array mode, the vertical attaching assembly is composed of two balance weight cylinders, and the flexible rubber sleeve is attached to a curved surface matched with the outer contour of an axle through the gravity action of the balance weight cylinders. According to the invention, high integration of dynamic loading and morphology adaptive detection of the axle is realized through modular design, the pneumatic and gravity synergistic effect breaks through the adaptive limitation of a traditional rigid clamp, the system is especially suitable for global strain field monitoring of the axle with a complex curved surface, and the test precision under a multi-directional load condition is improved.

Description

Technical Field

[0001] The present invention relates to the field of vehicle testing, and more specifically, it relates to a testing device for the structural strength of a trailer axle. Background Art

[0002] As a core component for carrying transportation loads, the structural strength of a trailer axle directly affects the safety performance of the entire vehicle. The axle strength detection device usually adopts a fixed structure, and simulates the stress conditions in actual use by applying static loads at both ends of the axle. As a core load-bearing component of the trailer, the structural strength of the axle is directly related to the safety, load-bearing capacity and service life of the vehicle. Traditional axle detection methods mostly use static loading or single-direction stress testing.

[0003] Traditional testing devices mostly use rigid fixtures for load application and strain detection, and their inherent defects are reflected in three aspects: First, as a complex spatial curved surface structure, it is difficult for a rigid fixture to fully conform to its outer contour, resulting in the omission of local stress concentration areas and insufficient integrity of test data; For this reason, we propose a testing device for the structural strength of a trailer axle. Summary of the Invention

[0004] The present invention provides a testing device for the structural strength of a trailer axle, which solves the technical problems of omission of local stress concentration areas and insufficient integrity of test data in related technologies.

[0005] The present invention provides a testing device for the structural strength of a trailer axle, including: a gantry main frame, with two hydraulic components symmetrically arranged below its cross beam;

[0006] An axle covering mechanism, symmetrically arranged on both sides of the telescopic arms of the hydraulic components, includes circumferentially distributed expansion air bags and retractable rubber ropes linked thereto, and the end of the retractable rubber rope is connected to a dynamic detection structure;

[0007] The dynamic detection structure includes a flexible rubber sleeve, a vertical attachment component and micro strain gauges of a strain detection network. Micro strain gauges are arranged in an array on the lower surface of the flexible rubber sleeve. The vertical attachment component consists of two counterweight cylinders, and the flexible rubber sleeve forms a curved surface fitting that matches the outer contour of the axle under the gravitational action of the counterweight cylinders;

[0008] Among them, when the expansion air bag is inflated, it drives the retractable rubber rope to unfold, driving the flexible rubber sleeve to unfold and wrap along the axle axis direction. When the hydraulic component applies multi-directional loads, the micro strain gauges collect real-time strain distribution data on the axle surface, and the vertical attachment component generates displacement compensation with the deformation of the axle to maintain the dynamic fitting of the strain gauges.

[0009] Furthermore, an axle dynamic simulation component is arranged at the position below the gantry main frame for placing the trailer axle to be detected. The telescopic arm bottom end of the hydraulic component is fixedly provided with a pressing claw.

[0010] Furthermore, the axle sleeve mechanism further includes a connecting column. An installation ring is fixedly arranged at one end of the connecting column close to the telescopic arm of the hydraulic component, and the installation ring is fixed on the outer wall of the telescopic arm of the hydraulic component.

[0011] Furthermore, a number of expansion air bags are provided and fixed on the connecting column. The expansion air bags communicate with the inside of the connecting column. The air inlet end of the connecting column is connected with an air supply pipe, and an air pump body is arranged at the end of the air supply pipe far from the connecting column.

[0012] Furthermore, a number of limiting rings are fixedly arranged on the ridges of the number of expansion air bags. The retractable rubber rope passes through the number of limiting rings in turn, and the retractable rubber rope is of a hollow structure. Two micro solenoid valves are arranged at the air inlet end of the retractable rubber rope, and the two micro solenoid valves respectively control the air inlet and air release of the retractable rubber rope. The micro solenoid valve for air inlet is communicated with the air supply pipe through a hose.

[0013] Furthermore, a secondary air bag is arranged on the side wall of the retractable rubber rope close to the spiral center. A secondary air control pipe is arranged inside the retractable rubber rope, and the diameter of the secondary air control pipe is smaller than the hollow diameter of the retractable rubber rope.

[0014] Furthermore, a flow guiding thin pipe is arranged between the secondary air control pipe and the secondary air bag. The secondary air bag is communicated with the secondary air control pipe through a number of flow guiding thin pipes, and the secondary air bag is not communicated with the retractable rubber rope.

[0015] Furthermore, a rotating column is rotatably arranged inside the counterweight cylinder. A magnetic strip is fixedly arranged on the lower wall of the rotating column, a stress plate is fixedly arranged on the upper wall of the rotating column, and a telescopic air column is fixedly arranged on one side of the stress plate. The telescopic air column is communicated with the secondary air control pipe, and the elastic force of the telescopic air column is greater than the elastic force of the secondary air bag.

[0016] Furthermore, the inside of the flexible rubber sleeve is divided into two layers of space. The first layer of space is provided with a hardening inner pipe with an S-shaped wire routing, and the second layer of space is a sealed water bag. The hardening inner pipe is communicated with the retractable rubber rope.

[0017] Furthermore, the connecting end of the micro strain gauge is connected with a main control wire, and the main control wire is connected with the main board of the intelligent control system.

[0018] The beneficial effects of the present invention are as follows:

[0019] The present invention realizes the highly integrated dynamic loading and morphology adaptive detection of the axle through modular design. Its core innovation lies in the adoption of a flexible sleeve mechanism driven by an inflatable airbag, which forms a dual adaptive fitting mechanism in cooperation with the gravity sagging component. The circumferentially distributed inflatable airbags can expand non-uniformly along the axle contour, driving the retractable rubber rope to drive the flexible rubber sleeve to unfold axially. In cooperation with the constant pressure fitting effect of the counterweight cylinder, it ensures that the strain detection network always maintains a micron-level dynamic contact with the axle surface. This synergistic effect of pneumatic and gravity breaks through the adaptation limitations of traditional rigid fixtures, is particularly suitable for the global strain field monitoring of axles with complex curved surfaces, significantly improves the test accuracy under multi-directional load conditions, and provides reliable data support for the structural durability assessment of heavy-duty vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is the overall structural schematic diagram of the present invention;

[0021] Figure 2 is the structural schematic diagram of the protective cylinder of the present invention;

[0022] Figure 3 is the internal structural schematic diagram of the protective cylinder of the present invention;

[0023] Figure 4 is the structural schematic diagram of the retractable rubber rope of the present invention;

[0024] Figure 5 is of the present invention Figure 4 magnified schematic diagram at position A in;

[0025] Figure 6 is the internal structural schematic diagram of the flexible rubber sleeve of the present invention;

[0026] Figure 7 is of the present invention Figure 6 magnified schematic diagram at position B in;

[0027] Figure 8 is the structural schematic diagram of the lower wall of the flexible rubber sleeve of the present invention.

[0028] In the figure: 11, gantry main frame; 12, hydraulic components; 14, axle dynamic simulation component; 15, pressing claw; 2, axle sleeve mechanism; 21, mounting ring; 22, protective cylinder; 23, connecting column; 24, inflatable airbag; 25, limit ring; 26, micro solenoid valve; 27, air supply pipe; 28, retractable rubber rope; 29, auxiliary airbag; 201, air control auxiliary pipe; 202, diversion capillary tube; 3, dynamic detection structure; 31, flexible rubber sleeve; 32, counterweight cylinder; 33, micro strain gauge; 34, hardening inner tube; 35, water bag; 36, telescopic air column; 37, rotating column; 38, magnetic strip; 39, stress plate; 301, main control line; 4, air pump body. DETAILED DESCRIPTION OF THE INVENTION

[0029] Reference will now be made to example embodiments to discuss the subject matter described herein. It should be understood that discussing these embodiments is only to enable those skilled in the art to better understand and thus implement the subject matter described herein, and changes can be made to the functions and arrangements of the elements discussed without departing from the scope of protection of the content of this specification. Each example can omit, substitute, or add various processes or components as needed. Additionally, the features described relative to some examples can also be combined in other examples.

[0030] As Figure 1 , Figure 2 , Figure 3 and Figure 4 shown, a trailer axle structure strength testing device includes: a gantry main frame 11, with two hydraulic components 12 symmetrically arranged below its cross beam;

[0031] An axle covering mechanism 2, symmetrically arranged on both sides of the telescopic arms of the hydraulic components 12, includes circumferentially distributed expansion airbags 24 and retractable and release ropes 28 linked therewith, and the end of the retractable and release rope 28 is connected to a dynamic detection structure 3;

[0032] The dynamic detection structure 3 includes a flexible rubber sleeve 31, a vertical attachment component, and micro strain gauges 33 of a strain detection network. The lower surface of the flexible rubber sleeve 31 is arranged with micro strain gauges 33 in an array. The vertical attachment component consists of two counterweight cylinders 32, and the gravity of the counterweight cylinders 32 causes the flexible rubber sleeve 31 to form a curved surface that fits the outer contour of the axle;

[0033] Among them, when the expansion airbag 24 is inflated, it drives the retractable and release rope 28 to unfold, driving the flexible rubber sleeve 31 to unfold and wrap along the axle axis direction. When the hydraulic component 12 applies multi-directional loads, the micro strain gauges 33 collect real-time strain distribution data on the axle surface, and the vertical attachment component generates displacement compensation with the deformation of the axle to maintain the dynamic fitting of the strain gauges.

[0034] A dynamic simulation component 14 of the trailer axle is arranged at the position where the trailer axle is placed below the gantry main frame 11. The dynamic simulation component 14 of the trailer axle is used to place the trailer axle to be detected, and a pressing claw 15 is fixedly arranged at the bottom end of the telescopic arm of the hydraulic component 12.

[0035] The axle covering mechanism 2 further includes a connecting column 23. One end of the connecting column 23 close to the telescopic arm of the hydraulic component 12 is fixedly provided with a mounting ring 21, and the mounting ring 21 is fixed on the outer wall of the telescopic arm of the hydraulic component 12.

[0036] A number of expansion airbags 24 are provided and fixed on the connecting column 23. The expansion airbags 24 are internally interconnected with the connecting column 23. The air inlet end of the connecting column 23 is connected to an air supply pipe 27, and an air pump body 4 is arranged at the end of the air supply pipe 27 away from the connecting column 23.

[0037] A number of limiting rings 25 are fixedly arranged on the ridges of a number of expansion air bags 24. A retractable rubber rope 28 passes through the number of limiting rings 25 in sequence. The retractable rubber rope 28 is of a hollow structure. Two micro solenoid valves 26 are arranged at the air inlet end of the retractable rubber rope 28. The two micro solenoid valves 26 respectively control the air inlet and air release of the retractable rubber rope 28. The micro solenoid valve 26 for air inlet is communicated with an air supply pipe 27 through a hose.

[0038] As Figure 5 , Figure 6 and Figure 7 shown, a secondary air bag 29 is arranged on the side wall of the retractable rubber rope 28 close to the spiral center. A secondary air control pipe 201 is arranged inside the retractable rubber rope 28. The diameter size of the secondary air control pipe 201 is smaller than the hollow diameter size of the retractable rubber rope 28.

[0039] A diversion capillary 202 is arranged between the secondary air control pipe 201 and the secondary air bag 29. The secondary air bag 29 is communicated with the secondary air control pipe 201 through a number of diversion capillaries 202, and the secondary air bag 29 is not communicated with the retractable rubber rope 28.

[0040] A rotating column 37 is rotatably arranged inside a counterweight cylinder 32. A magnetic strip 38 is fixedly arranged on the lower wall of the rotating column 37. A stress plate 39 is fixedly arranged on the upper wall of the rotating column 37. A telescopic air column 36 is fixedly arranged on one side of the stress plate 39. The telescopic air column 36 is communicated with the secondary air control pipe 201, and the elastic force of the telescopic air column 36 is greater than the elastic force of the secondary air bag 29.

[0041] The inside of a flexible rubber sleeve 31 has two layers of space. The first layer of space is provided with a hardening inner pipe 34 with an S-shaped wire routing. The second layer of space is a sealed water bag 35. The hardening inner pipe 34 is communicated with the retractable rubber rope 28.

[0042] As Figure 8 shown, the connecting end of a micro strain gauge 33 is connected with a main control wire 301, and the main control wire 301 is connected with the main board of an intelligent control system.

[0043] First, place the trailer axle to be detected on the axle dynamic simulation part 14. Then, drive the pressure applying claws 15 to descend through the telescopic arms of the two hydraulic parts 12 and press on the trailer axle. Gradually apply pressure to the trailer axle according to the strength detection requirements.

[0044] Before detecting the pressure applied to the trailer axle, control the expansion air bag 24 to deflate and shrink through the valve at the air supply end of the air pump body 4. While the expansion air bag 24 shrinks, the weight of the flexible rubber sleeve 31 is added to pull the retractable rubber rope 28 to extend along the limiting ring 25. As the limiting ring 25 extends, the flexible rubber sleeve 31 automatically descends to the trailer axle, and the flexible rubber sleeve 31 is distributed on both sides of the pressure applying claws 15.

[0045] When the flexible rubber sleeve 31 contacts the trailer axle, a certain amount of air is stored in the retractable rubber rope 28 and the hard inner tube 34. Under the support of air pressure, the hard inner tube 34 props up the flexible rubber sleeve 31 to form an arc, so that the flexible rubber sleeve 31 can be ensured to be in stable contact and prevented from closing together under the gravity of the two counterweight cylinders 32. When the flexible rubber sleeve 31 drops to the preset position, the micro solenoid valve 26 is controlled by the intelligent control system to release the air in the hard inner tube 34. At this time, the flexible rubber sleeve 31 softens and is naturally laid on the trailer axle under the gravity of the two counterweight cylinders 32.

[0046] While the rubber rope 28 is being retracted and extended, the auxiliary airbag 29 is squeezed, and the air in the auxiliary airbag 29 is squeezed into the air control auxiliary pipe 201, and then enters the telescopic air column 36, so that the telescopic air column 36 expands and extends. The extension of the telescopic air column 36 pushes the force-bearing plate 39, thereby driving the rotating column 37 to rotate, so that the magnetic strip 38 rotates to the side close to the trailer axle, so that it is adsorbed on the trailer axle, ensuring that the flexible rubber sleeve 31 will not be displaced due to the compression and deformation of the trailer axle;

[0047] The protective sleeve 22 is disposed outside the inflation bag.

[0048] When the flexible rubber sleeve 31 softens, the liquid in the water bag 35 can ensure that the flexible rubber sleeve 31 fits more closely to the trailer axle and can also generate displacement compensation as the axle deforms.

[0049] When the detection is completed, the air pump body 4 is used to inflate the expansion bag 24, causing the expansion bag 24 to expand, thereby pulling the flexible rubber sleeve 31 up, and another micro solenoid valve 26 controls the air in the air supply pipe 27 to enter the retractable rubber rope 28, so that the hardened inner tube 34 becomes hard, supporting the flexible rubber sleeve 31.

[0050] Dynamic fit stage:

[0051] Airbag contraction and rubber sleeve expansion: The air pump body 4 supplies air to the inflatable airbag 24 at a pressure of 0.6 MPa, and the airbag contracts and the volume change rate is 85%, driving the release length of the retractable rubber rope 28 to 1.2 m. The flexible rubber sleeve 31 descends at a speed of 3 cm / s under the action of gravity.

[0052] Three-level fit control:

[0053] Primary support: The hard inner tube 34 is maintained at an air pressure of 0.2 MPa, so that the flexible rubber sleeve 31 forms a rigid support surface with a preset curvature radius R=90 mm.

[0054] Adaptive adjustment: After triggering the positioning signal, the micro solenoid valve 26 completes the pressure relief of the hardening inner tube 34 within 0.5 s, and the pressure drops to 0.05 MPa. The counterweight cylinder 32 drives the flexible rubber sleeve 31 to achieve full-surface fitting, and the contact pressure is evenly distributed in the range of 0.8 - 1.2 N / cm².

[0055] Magnetic adsorption compensation: The 0.15 MPa air flow generated by the compression of the auxiliary airbag 29 drives the telescopic air column 36 to elongate by 15 mm, driving the magnetic strip 38, and the magnetic force intensity of 0.8 T completes the magnetic adsorption with the axle, and the displacement compensation ability reaches ±10 mm.

[0056] Multi-directional load application stage:

[0057] The hydraulic component 12 applies multi-directional loads according to a preset program: In the vertical direction: step loading from 0 - 30 T at a rate of 5 T / s.

[0058] Lateral torsional load: reciprocating swing of ±15° at a frequency of 0.5 Hz.

[0059] Impact load: peak value of 40 T and duration of 50 ms.

[0060] The axle dynamic simulation component 14 synchronously provides support stiffness adjustment in the range of 10 - 100 kN / mm to simulate the constraint conditions under actual working conditions.

[0061] Data acquisition stage:

[0062] Micro strain gauge 33 array: 200 micro strain gauges 33 are arranged on the lower surface of the flexible rubber sleeve 31, with a grid length of 2 mm and a sensitivity coefficient of 2.0 ± 1%. The surface strain data is collected at a sampling frequency of 1 kHz.

[0063] Traditional strain gauge testing requires manual wiring. This device adopts a modular design. Each single dynamic detection structure 3 integrates 128-channel strain measurement. With the daisy-chain connection of the main control line 301, it can be expanded to 512 channels. The actual measurement shows that the system synchronous acquisition error is less than 2 μs, meeting the requirements of multi-axis fatigue testing.

[0064] The micro strain gauge 33 uses a flexible circuit board to achieve the integration of 200 measuring point lines, and the wiring thickness is only 0.6 mm.

[0065] Detection efficiency:

[0066] It can synchronously capture the micro strain changes of the axle surface at the order of 10⁻⁶.

[0067] The system can still maintain an effective data acquisition rate of 98% under a 40 T impact load.

[0068] Engineering value: The measured three-dimensional strain distribution cloud map can accurately locate the stress concentration area, providing a direct basis for the optimization of the axle structure.

[0069] Dynamic compensation mechanism:

[0070] The sealed water bag 35 is filled with silicone oil with a viscosity of 50 cSt, and the deformation of the axle is adaptively compensated through fluid pressure, and the compensation response time < 20 ms.

[0071] Data transmission: The main control line 301 adopts the CAN bus protocol to transmit data to the intelligent control system in real time. The system built-in AI algorithm performs real-time filtering and anomaly detection on the 120-channel data stream.

[0072] Improve detection accuracy: Through the close fit of the flexible rubber sleeve 31 with the axle and the real-time data acquisition of the micro strain gauge 33, the strain of the axle under different loads can be more accurately reflected, providing more reliable data support for the strength evaluation of the axle.

[0073] Ensure data stability: The vertical attachment component generates displacement compensation with the deformation of the axle, maintaining the dynamic fit of the strain gauge, ensuring that during the deformation of the axle, the strain gauge can still stably collect data, avoiding data loss or errors caused by the displacement or detachment of the strain gauge.

[0074] Enhance fit and adaptability: The liquid in the water bag 35 enables the flexible rubber sleeve 31 to better adapt to the irregular shape of the axle surface, improving the fit, and at the same time providing displacement compensation when the axle is compressed and deformed, ensuring the continuity and accuracy of the detection process.

[0075] Easy to operate and high degree of automation: The entire detection process is controlled by the intelligent control system, including the pressurization of the hydraulic component 12, the inflation and deflation of the expansion airbag 24, the switching of the micro solenoid valve 26, etc. It is easy to operate, has a high degree of automation, reduces manual intervention, and improves the detection efficiency and safety.

[0076] Protect the axle surface: The flexible rubber sleeve 31 plays a certain protective role on the axle surface during the detection process, avoiding scratches or damage that may be caused by the direct contact of hard detection components with the axle surface.

[0077] Strong repeatability and reliability: The structural design and working principle of this test device enable it to be reused multiple times, and the results of each detection have high reliability and consistency, providing a strong guarantee for the quality control and performance evaluation of the trailer axle.

[0078] The above describes the embodiments of the present invention, but the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of this embodiment, those of ordinary skill in the art can also make many forms, all of which fall within the protection scope of this embodiment.

Claims

1. A trailer axle structure strength testing device, characterized in that: include: The main gantry frame (11) has two hydraulic components (12) symmetrically arranged below its crossbeam; The axle covering mechanism (2) is symmetrically arranged on both sides of the telescopic arm of the hydraulic component (12), and comprises circumferentially distributed expansion airbags (24) and retractable rubber ropes (28) linked thereto, wherein the ends of the retractable rubber ropes (28) are connected to the dynamic detection structure (3); The dynamic detection structure (3) comprises a flexible rubber sleeve (31), a vertically attached component and a micro strain gauge (33) of a strain detection network; the micro strain gauges (33) are arranged in an array on the lower surface of the flexible rubber sleeve (31); the vertically attached component is composed of two counterweight cylinders (32); and the gravity of the counterweight cylinders (32) causes the flexible rubber sleeve (31) to form a curved surface that matches the outer contour of the axle; When the inflatable airbag (24) is inflated, it drives the retractable rubber rope (28) to unfold, driving the flexible rubber sleeve (31) to unfold and cover along the axis of the vehicle axle; when the hydraulic component (12) applies a multi-directional load, the micro strain gauge (33) collects strain distribution data on the surface of the vehicle axle in real time, and the vertical contact component generates displacement compensation as the vehicle axle deforms, thereby maintaining the dynamic contact of the strain gauge.

2. A trailer axle structure strength testing device according to claim 1, characterized in that: A vehicle axle dynamic simulation component (14) is provided at a position where a trailer axle is placed below the main gantry frame (11), and the vehicle axle dynamic simulation component (14) is used to place a trailer axle to be tested, and a pressure claw (15) is fixedly provided at the bottom end of the telescopic arm of the hydraulic component (12).

3. A trailer axle structure strength testing device according to claim 1, characterized in that: The axle covering mechanism (2) further comprises a connecting column (23), one end of the connecting column (23) close to the telescopic arm of the hydraulic component (12) being fixedly provided with a mounting ring (21), and the mounting ring (21) being fixed to the outer wall of the telescopic arm of the hydraulic component (12).

4. A trailer axle structure strength testing device according to claim 3, characterized in that: A plurality of expansion air bags (24) are provided and fixed on the connecting column (23); the expansion air bags (24) and the interior of the connecting column (23) are in communication with each other; an air supply pipe (27) is connected to the air inlet end of the connecting column (23); an air pump body (4) is provided at one end of the air supply pipe (27) away from the connecting column (23).

5. A trailer axle structure strength testing device according to claim 4, characterized in that: A plurality of limiting rings (25) are fixedly arranged on the ridges of the plurality of inflatable air bags (24); the retractable rubber rope (28) passes through the plurality of limiting rings (25) in sequence; the retractable rubber rope (28) is a hollow structure; two micro solenoid valves (26) are arranged at the air inlet end of the retractable rubber rope (28); the two micro solenoid valves (26) respectively control the air intake and air discharge of the retractable rubber rope (28); and the micro solenoid valve (26) for air intake is connected to the air supply pipe (27) through a hose.

6. The trailer axle structure strength testing device according to claim 1, characterized in that: A secondary air bag (29) is provided on the side wall of the retractable rubber rope (28) close to the spiral center, and a secondary air control pipe (201) is provided inside the retractable rubber rope (28). The diameter of the secondary air control pipe (201) is smaller than the diameter of the hollow core of the retractable rubber rope (28).

7. A trailer axle structure strength testing device according to claim 6, characterized in that: A flow guiding tube (202) is provided between the air control auxiliary tube (201) and the auxiliary air bag (29); the auxiliary air bag (29) is connected to the air control auxiliary tube (201) via a plurality of flow guiding tubes (202), and the auxiliary air bag (29) is not connected to the retractable rubber rope (28).

8. The trailer axle structure strength testing device according to claim 7, characterized in that: A rotating column (37) is rotatably arranged inside the counterweight cylinder (32), a magnetic strip (38) is fixedly arranged on the lower wall of the rotating column (37), a force-bearing plate (39) is fixedly arranged on the upper wall of the rotating column (37), a telescopic gas column (36) is fixedly arranged on one side of the force-bearing plate (39), the telescopic gas column (36) is communicated with the auxiliary gas control pipe (201), and the elastic force of the telescopic gas column (36) is greater than the elastic force of the auxiliary air bag (29).

9. The trailer axle structure strength testing device according to claim 1, characterized in that: The interior of the flexible rubber sleeve (31) is divided into two layers of space. The first layer of space is provided with a hard inner tube (34) arranged in an S-shaped pattern. The second layer of space is a sealed water bag (35). The hard inner tube (34) is in communication with the retractable rubber rope (28).

10. The trailer axle structure strength testing device according to claim 1, characterized in that: The connection end of the micro strain gauge (33) is connected to a master control line (301), and the master control line (301) is connected to a main board of the intelligent control system.

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