Loading device and ring road acceleration loading test system

Abstract

The application provides a loading device and a loop track accelerated loading test system, and belongs to the technical field of road performance testing. The loading device comprises a gantry frame, a bearing frame, an equal load beam and a loading vehicle. The two sides of the gantry frame are respectively provided with rail wheel sets, and the rail wheel sets on the two sides are respectively used for clamping and rolling the tracks on the two sides of the test loop track. The bearing frame is slidingly connected to the middle part of the gantry frame along the road width direction of the test loop track, and a pressure sensor is arranged between the two sides of the bearing frame and the gantry frame. One side of the equal load beam is hingedly connected to the bearing frame, and the other side is connected to the bearing frame through a loading cylinder. The middle part of the loading vehicle is provided with a connecting beam, and the connecting beam is hingedly connected to the middle part of the equal load beam. The loading cylinder is provided with an adjusting part for flexibly adjusting the jacking force. The pressure sensor is used for detecting the lateral force transmitted to the bearing frame when the loading vehicle turns. The loading device provided by the application can improve the comprehensiveness of the loop track accelerated loading test data.

Description

Technical Field

[0001] This invention belongs to the field of road performance testing technology, specifically relating to a loading device and a ring track accelerated loading test system. Background Technology

[0002] Accelerated loading tests are used to comprehensively simulate the actual service conditions of pavement materials and structures under special geographical environments, and are of great importance for research on new pavement structures, materials, and processes. Accelerated loading test projects mainly include two types: straight-track accelerated loading tests and circular-track accelerated loading tests.

[0003] In the case of the ring track acceleration loading test, the ring track structure is typically a circular track consisting of two curves and two straight sections, thus enabling the continuity of the acceleration loading test. However, due to the current use of level road surfaces, the ring track acceleration loading test lacks effective simulation conditions for the actual working conditions of vehicles going uphill and downhill; furthermore, the impact of road surface performance on sideslip during vehicle cornering cannot be effectively tested. Therefore, there is still significant room for improvement in the comprehensiveness of data from the ring track acceleration loading test, and a more comprehensive test scheme urgently needs to be developed. Summary of the Invention

[0004] This invention provides a loading device and a ring-track accelerated loading test system, aiming to improve the comprehensiveness of ring-track accelerated loading test data.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: Firstly, a loading device is provided, comprising: The gantry frame is equipped with rail wheel sets on both sides. The rail wheel sets on both sides are used to clamp and roll the rails on both sides of the test ring. The support frame is slidably connected to the middle of the gantry frame along the width of the test track, and pressure sensors are installed on both sides of the support frame and between the support frame and the gantry frame. The load-bearing beam is hinged to the load-bearing frame on one side and connected to the load-bearing frame on the other side via a loading cylinder; The loading vehicle has a connecting beam in the middle, which is hinged to the load-sharing beam at the middle. The loading cylinder is used to push the load-equalizing beam to apply load to the test track surface of the loading vehicle. The loading cylinder has an adjustment component for flexibly adjusting its pushing force. The pressure sensor is used to detect the lateral force transmitted to the load-bearing frame when the loading vehicle turns a corner.

[0006] In conjunction with the first aspect, in one possible implementation, the loading cylinder includes: The cylinder body is hinged to the outside of the support frame and is equipped with an adjusting component; The pressure regulating piston is slidably connected to the cylinder body and is drivenly connected to the adjusting component. The pressure regulating piston divides the inside of the cylinder body into a sealed medium cavity, which is filled with fluid. The loading piston is slidably connected in the medium cavity. The loading piston has a loading rod that extends downward through the cylinder and is hinged to the load equalizing beam. The loading piston also has a damping hole that extends vertically through the cylinder. The adjusting component is used to drive the pressure regulating piston to move up and down to adjust the volume of the medium cavity, and the damping orifice is used to balance the fluid pressure on both sides of the loading piston.

[0007] In some embodiments, the loading piston divides the medium chamber into a rodless chamber and a rod chamber; the rodless chamber is provided with a first high-pressure airbag, and the rod chamber is provided with a second high-pressure airbag.

[0008] For example, the loading piston has a liquid flow hole that runs vertically through it, and a liquid flow valve is provided inside the liquid flow hole; wherein, the liquid flow valve opens when the fluid pressure difference on both sides of the loading piston is greater than a set threshold, and closes when the fluid pressure difference on both sides of the loading piston is less than or equal to the set threshold.

[0009] For example, a flow valve includes: The valve body is embedded in the liquid flow hole, and a valve hole is provided through the center of the valve body along its axial direction. The valve hole includes a small diameter section and two large diameter sections located at both ends of the small diameter section. The valve core is slidably connected to the small diameter section. The valve core has a through hole in the center and an annular groove in the middle of the outer periphery of the valve core. The annular groove and the through hole are connected through a radial hole. Two valve stems are fixedly connected to two large-diameter sections respectively, and are respectively inserted into the two ends of the through hole. Each valve stem is fitted with an elastic element that abuts against the valve core. Specifically, when the fluid pressure difference across the loading piston is greater than a set threshold, the valve core slides to the low-pressure side to the open state based on the pressure difference, overcoming the elastic force of the elastic element; when the fluid pressure difference across the loading piston is equal to or less than the set threshold, the valve core resets under the action of the elastic force of the elastic element and remains in the closed state.

[0010] For example, the adjusting element includes: The rotary drive component is fixedly connected to the outer wall of the cylinder body; The rotating sleeve is rotatably connected to the center of the top wall of the cylinder. The drive rod is connected to the pressure regulating piston at one end and passes through the rotating sleeve at the other end, which is connected to the output end of the rotary drive component. The drive rod and the rotating sleeve are threaded together.

[0011] In conjunction with the first aspect, in one possible implementation, the front and rear ends of the gantry frame are provided with sliding grooves, and the front and rear ends of the support frame are respectively slidably connected to the two sliding grooves; each sliding groove is provided with two pushers, which are located on both sides of the support frame, and each pusher is provided with a pressure sensor between it and the support frame.

[0012] In some embodiments, the pushing component is a telescopic cylinder, the output end of which is provided with an elastic support, and the pressure sensor is located between the elastic support and the side wall of the support frame.

[0013] For example, the upper and lower sides of the end of the support frame that extends into the chute are provided with rollers, and each roller rolls against the chute wall.

[0014] In some possible implementations, the loading device also includes a controller, which is electrically connected to the pressure sensor, the regulator and the loading vehicle, and wirelessly connected to a remote industrial computer.

[0015] The beneficial effects of the loading device provided by the present invention are as follows: Compared with the prior art, the loading device of the present invention uses the rail wheel groups on both sides of the gantry frame to clamp and roll the rails on both sides of the test ring track, which not only ensures the movement stability of the gantry frame along the test ring track, but also ensures that the loading force transmitted to the loading vehicle is sufficient and stable by means of the reaction force provided by the rails.

[0016] One side of the load-equalizing beam is hinged to the loading beam. When loading is required, the other side of the load-equalizing beam is pushed by the loading cylinder, which causes the load-equalizing beam to swing down and transfer the load to the loading vehicle through the hinge point in its middle. This allows the loading vehicle to apply the load to the test track surface. On the one hand, this avoids the motion jamming that is common in traditional overall lifting loading methods. On the other hand, by using a centrally located hinge point to transfer the load, it avoids uneven load distribution on both sides of the loading vehicle, thereby improving test accuracy.

[0017] During testing, the jacking force of the loading cylinder can be adjusted by adjusting the adjustment component to simulate the load changes on the road surface when the loading vehicle goes up and down the slope, thereby improving the comprehensiveness of data collection in the accelerated loading test. Moreover, the adjustment of the jacking force is flexible, which can avoid the impact problem caused by direct adjustment, thus ensuring the service life of the loading cylinder.

[0018] In addition, when the loading vehicle passes through a curve, the pressure sensor can detect the lateral force transmitted from the loading vehicle to the support frame, thereby judging the lateral slip tendency between the loading vehicle and the road surface through the lateral force, and further improving the comprehensiveness of the road performance test data.

[0019] Secondly, embodiments of the present invention also provide a ring-track accelerated loading test system, including a test ring track, a track laid along the test ring track, and the aforementioned loading device.

[0020] The beneficial effects of the ring track accelerated loading test system provided by the present invention are as follows: Compared with the prior art, the ring track accelerated loading test system of the present invention adopts the above-mentioned loading device, which can use the detection value of the pressure sensor to feed back the data on the influence of road surface performance on sideslip during the cornering process of the loading vehicle, and at the same time use the adjusting component to flexibly adjust the jacking force of the loading cylinder to simulate the scenario of the loading vehicle going up and down the slope, thereby further improving the comprehensiveness of data acquisition in the accelerated loading test. Attached Figure Description

[0021] Figure 1 This is a three-dimensional structural diagram of the loading device provided in an embodiment of the present invention; Figure 2 This is a front view of the loading device provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the connection structure between the support frame and the gantry frame in an embodiment of the present invention; Figure 4 For along Figure 3 Schematic diagram of the cross-sectional structure along line AA; Figure 5 This is a cross-sectional view of the loading cylinder used in an embodiment of the present invention; Figure 6 This is a cross-sectional view of the flow valve used in the embodiment of the present invention in the closed state. Figure 7 This is a cross-sectional view of the flow valve used in the embodiment of the present invention in the open state.

[0022] In the diagram: 10. Gantry frame; 11. Rail wheel assembly; 12. Slide rail; 121. Pushing component; 122. Elastic support component; 20. Bearing frame; 21. Roller assembly; 30. Pressure sensor; 40. Load-equalizing beam; 50. Loading cylinder; 51. Cylinder body; 511. Medium chamber; 512. Rodless chamber; 5121. First high-pressure airbag; 5122. First inflation port; 5123. First air valve; 513. Rod chamber; 5131. Second high-pressure airbag; 5132. Second inflation port; 5133. Second air... 52. Valve; 53. Pressure regulating piston; 54. Loading piston; 55. Loading rod; 56. Damping orifice; 67. Loading carriage; 68. Connecting beam; 79. Adjusting component; 70. Rotary drive component; 71. Rotating sleeve; 72. Drive rod; 83. Test ring track; 84. Track; 95. Fluid flow valve; 96. Valve body; 97. Valve orifice; 98. Small diameter section; 99. Large diameter section; 90. Valve core; 91. Through hole; 92. Annular groove; 92. Radial hole; 92. Valve stem; 92. Elastic component. Detailed Implementation

[0023] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0024] It should be noted that when an element is referred to as being "set on" or "connected to" another element, it can be directly on or indirectly on the other element. It should be understood that the terms "upper," "lower," "front," "rear," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" or "several" means two or more, unless otherwise explicitly specified.

[0025] It is important to understand that for the accelerated loading test of the ring track, the test track is constructed on the test site according to the design materials, road structure and paving process. The test track is similar to the traditional runway structure, consisting of two straight sections and two curves. The traditional accelerated loading test mainly focuses on obtaining test data for the load applied to the straight sections, while the curves mainly serve to ensure the continuity of the test process.

[0026] The more pavement performance parameters obtained through accelerated loading tests, the more beneficial it is for research on pavement structure, materials, and process innovation and improvement. Therefore, the comprehensiveness of the test data is crucial. Traditional accelerated loading tests are usually limited to simulating the condition of a vehicle traveling in a straight line on a level road surface. Based on this condition, different parameters are obtained by changing the pavement temperature, humidity, and other conditions of the test track. However, actual pavements often have many uphill, downhill, and curve conditions. It is impossible to obtain accurate data to verify whether the vehicle has the same performance as a straight road surface under these conditions. This is the main problem that this application focuses on solving.

[0027] Please refer to the following: Figures 1 to 7The loading device provided by the present invention will now be described. The loading device includes a gantry frame 10, a support frame 20, a load-equalizing beam 40, and a loading vehicle 60. Wheel sets 11 are respectively provided on both sides of the gantry frame 10, and the wheel sets 11 on both sides are used to clamp and roll the tracks 81 on both sides of the test ring track 80. The support frame 20 is slidably connected to the middle of the gantry frame 10 along the width direction of the test ring track 80, and pressure sensors 30 are provided between both sides of the support frame 20 and the gantry frame 10. One side of the load-equalizing beam 40 is hinged to the support frame 20, and the other side is connected to the support frame 20 through a loading cylinder 50. A connecting beam 61 is provided in the middle of the loading vehicle 60, and the connecting beam 61 is hinged to the middle of the load-equalizing beam 40.

[0028] The loading cylinder 50 is used to push the load-equalizing beam 40 so that the loading vehicle 60 applies a load to the road surface of the test loop 80, and the loading cylinder 50 has an adjusting member 70 for flexibly adjusting its pushing force, and the pressure sensor 30 is used to detect the lateral force transmitted to the bearing frame 20 when the loading vehicle 60 turns.

[0029] It should be noted that the wheel sets 11 on both sides of the gantry frame 10 each include at least one wheel rolling on the upper rail surface of the track 81 and at least two wheels rolling on the lower rail surface of the track 81, thereby forming an upper and lower clamping of the track 81.

[0030] The loading vehicle 60 can be a single-axle vehicle or a multi-axle vehicle based on the actual wheel set of the vehicle. Its axles can be driven by a motor. The motor can draw power through the contact between the brushes set on the gantry frame 10 and the cable laid along the track 81. This driving and motor power drawing method is a common technical means in this field and will not be described in detail here.

[0031] The support frame 20 is slidably connected to the gantry frame 10, giving it the freedom to slide along the width of the road surface. Based on this, pressure sensors 30 are installed on both sides between the support frame 20 and the gantry frame 10. When the centrifugal force generated by the circular motion of the loading vehicle 60 as it passes through a curve exceeds the friction between its tires and the road surface, the loading vehicle 60 transmits a lateral force of lateral displacement along the width of the road surface to the support frame 20 through the load-equalizing beam 40. The function of the pressure sensors 30 is to detect the magnitude of this lateral force. Since the speed V of the loading vehicle 60, the radius R of the curve, and the load N applied by the loading vehicle 60 to the road surface are all known quantities, the magnitude of the centrifugal force F can be calculated as MV. 2 / R, where M=N / g, and g is the acceleration due to gravity. The difference between the centrifugal force F and the value detected by the pressure sensor 30 is the lateral friction force f between the tires of the loading vehicle 60 and the road surface. Based on this, the ratio of the lateral friction force f to the load N applied by the loading vehicle 60 to the road surface is the road friction coefficient. This friction coefficient is related to the lateral slip phenomenon during vehicle driving, but it is not the same as the linear friction coefficient between the road surface and the tires under normal straight-line driving conditions of the loading vehicle 60.

[0032] When a vehicle enters an uphill section from a level road, its center of gravity shifts towards the rear axle. Therefore, although the total load on the road surface decreases slightly, the load on the rear axle increases, while the load on the front axle decreases. Similarly, when a vehicle enters a downhill section, its center of gravity shifts forward, resulting in a decrease in the load on the rear axle and an increase in the load on the front axle. Therefore, in this embodiment, the adjusting element 70 is used to adjust the pushing force of the loading cylinder 50, thereby changing the load of the loading vehicle 60 on the test road surface, thus simulating the working conditions of a vehicle going uphill or downhill.

[0033] The load-equalizing beam 40 is hinged to the bearing frame 20 in the middle. This allows the load to be transferred to the load-equalizing beam 40 through the hinge point and evenly distributed to the two wheels of the loading vehicle 60 when the loading cylinder 50 pushes the bearing frame 20 to swing. This avoids uneven load on both sides of the loading vehicle 60.

[0034] Compared with the prior art, the loading device provided in this embodiment uses a gantry frame 10 as the installation base, which can span across the road surface of the test ring track 80, thereby providing sufficient installation space and a stable leverage point for the loading vehicle 60. In terms of connection structure, the rail wheel sets 11 on both sides of the gantry frame 10 can clamp and roll the rails 81 on both sides of the test ring track 80 respectively. This not only ensures the movement stability of the gantry frame 10 along the test ring track 80, but also ensures that the loading force transmitted to the loading vehicle 60 is sufficient and stable by means of the reaction force provided by the rails 81.

[0035] One side of the load-equalizing beam 40 is hinged to the loading beam. When loading is required, the other side of the load-equalizing beam 40 is pushed by the loading cylinder 50, which causes the load-equalizing beam 40 to swing down and transfer the load to the loading vehicle 60 through the hinge point in its middle. This allows the loading vehicle 60 to apply the load to the road surface of the test track 80. On the one hand, this avoids the problem of motion jamming that is common in traditional overall lifting loading methods. On the other hand, by using a centrally located hinge point to transfer the load, it avoids uneven load distribution on both sides of the loading vehicle 60, thereby improving the accuracy of the test.

[0036] During testing, the jacking force of the loading cylinder 50 can be adjusted by adjusting the adjusting component 70 to simulate the load changes on the road surface when the loading vehicle 60 goes up and down the slope, thereby improving the comprehensiveness of data collection in the accelerated loading test. Moreover, the adjustment of the jacking force is flexible, which can avoid the impact problem caused by direct adjustment, thus ensuring the service life of the loading cylinder 50.

[0037] In addition, when the loading vehicle 60 passes through a curve, the pressure sensor 30 can detect the lateral force transmitted from the loading vehicle 60 to the support frame 20, thereby judging the lateral slip tendency data between the loading vehicle 60 and the road surface through the lateral force, and further improving the comprehensiveness of the road performance test data.

[0038] In some embodiments, see Figure 5 The loading cylinder 50 includes a cylinder body 51, a pressure regulating piston 52, and a loading piston 53. The cylinder body 51 is hinged to the outside of the support frame 20 and is provided with an adjusting member 70. The pressure regulating piston 52 is slidably connected inside the cylinder body 51 and is drivenly connected to the adjusting member 70. The pressure regulating piston 52 divides the interior of the cylinder body 51 into a sealed medium cavity 511, which is filled with fluid. The loading piston 53 is slidably connected inside the medium cavity 511. The loading piston 53 has a loading rod 531 that extends downward through the cylinder body 51 and is hinged to the load equalizing beam 40. The loading piston 53 also has a damping hole 532 that extends vertically. The adjusting member 70 is used to drive the pressure regulating piston 52 to move up and down to adjust the volume of the medium cavity 511. The damping hole 532 is used to balance the fluid pressure on both sides of the loading piston 53.

[0039] The cylinder body 51 is hinged to the support frame 20 to ensure that the cylinder body 51 can swing adaptively when the loading cylinder 50 pushes the load-equalizing beam 40, avoiding damage to the seal or other damage caused by the cylinder body 51 and loading cylinder 50 bearing additional bending moment during the loading process. It should be understood that since the difference in contact area between the piston and the fluid on both sides is equal to the cross-sectional area of ​​the loading cylinder 50, when the fluid pressure on both sides of the loading piston 53 is balanced, the load applied by the loading piston 53 to the load-equalizing beam 40 through the loading rod 531 is the product of the fluid pressure and the cross-sectional area of ​​the loading rod 531.

[0040] When the output load needs to be increased, the adjusting component 70 drives the pressure regulating piston 52 downward, thereby reducing the volume of the medium cavity 511 and increasing the fluid pressure on the upper side of the loading piston 53, thus increasing the downward pushing force of the loading piston 53. At this time, the load change of the rear axle on the road surface when the vehicle is going uphill can be simulated by the loading vehicle 60. When the output load needs to be reduced, the adjusting component 70 drives the pressure regulating piston 52 upward, thereby increasing the volume of the medium cavity 511 and decreasing the fluid pressure on the upper side of the loading piston 53, thus reducing the downward pushing force of the loading piston 53, thereby simulating the load change of the rear axle on the road surface when the vehicle is going downhill.

[0041] Based on the above, by providing a damping hole 532 on the loading piston 53 to connect the cavity spaces on both sides of the loading piston 53, fluid can flow from the upper side to the lower side of the loading piston 53 through the damping hole 532 when the pressure regulating piston 52 moves downward, until the fluid pressure on both sides of the loading piston 53 is equal. This can buffer the impact of the fluid on the loading piston 53 and cylinder 51 when the pressure regulating piston 52 moves downward, achieving flexible adjustment of the pushing force. On the other hand, it can simulate a more realistic working condition of a vehicle moving from a level road to an uphill road. Taking the rear axle load of a vehicle as an example, the principle is as follows: In the actual process of a vehicle going uphill, the load on the road surface increases sharply the moment the rear axle enters the uphill road surface from the horizontal road surface, and then gradually decreases to a stable state. In the stable state, the load on the road surface by the rear axle is still higher than that of driving on the horizontal road surface.

[0042] In response to the above actual working conditions, since the process of fluid passing through the damping hole 532 to achieve fluid pressure balance on both sides of the loading piston 53 is a slow one, the fluid pressure on the upper side of the loading piston 53 is higher than the fluid pressure on the lower side of the loading piston 53 at the instant when the adjusting component 70 drives the pressure regulating piston 52 downward, thereby increasing the pushing force of the loading piston 53 instantaneously, thus simulating the instant when the vehicle enters the uphill road surface; as the fluid gradually passes through the damping hole 532 and the fluid pressure on both sides of the loading piston 53 is balanced, the pushing force output by the loading piston 53 gradually decreases until it reaches a stable state, thus simulating the working condition of the vehicle driving stably on the uphill road surface.

[0043] Similarly, in the actual process of a vehicle descending a slope, the load on the road surface decreases sharply the moment the rear axle enters the downhill section from a level surface, and then gradually increases to a stable state. Corresponding to this process, the fluid pressure on the upper side of the loading piston 53 decreases the moment the pressure regulating piston 52 moves upward, while the fluid pressure on the lower side of the loading piston 53 remains unchanged. This results in a rapid decrease in output load. Then, as the fluid continuously passes through the damping orifice 532 and enters the upper cavity of the loading piston 53 under the action of pressure difference, the output load gradually increases. When the fluid pressure on both sides of the loading piston 53 is balanced, the output load also tends to stabilize.

[0044] For some possible implementations, please refer to [link / reference]. Figure 5 The loading piston 53 divides the medium chamber 511 into a rodless chamber 512 and a rod chamber 513. The rodless chamber 512 is provided with a first high-pressure airbag 5121, and the rod chamber 513 is provided with a second high-pressure airbag 5131.

[0045] Since the loading cylinder 50 extends through the cylinder body 51 to the lower side of the loading piston 53, the upper side of the loading piston 53 is a rodless chamber 512, while the lower side of the loading piston 53 is formed by the loading rod 531, and the loading piston 53 outputs a thrust by utilizing the difference in contact area between the fluid in the rodless chamber 512 and the rod chamber 513 and the loading piston 53.

[0046] The function of the first high-pressure airbag 5121 and the second high-pressure airbag 5131 is that the fluid filled in the medium cavity 511 is a liquid such as hydraulic oil, which has a low compression ratio, while the first high-pressure airbag 5121 and the second high-pressure airbag 5131 are filled with a gas with a high compression ratio, such as air or inert gas.

[0047] When the pressure regulating piston 52 moves downward, the instantaneous increase in fluid pressure in the rodless chamber 512 causes the thrust output of the loading piston 53 to increase instantaneously. At the same time, the first high-pressure airbag 5121 is also compressed. This can buffer the fluid impact on the one hand, and on the other hand, when the fluid in the rodless chamber 512 gradually enters the rod chamber 513 through the damping orifice 532, the first high-pressure airbag 5121 can expand and drive the fluid, thereby improving the fluid pressure balance efficiency.

[0048] When the pressure regulating piston 52 moves upward, the fluid pressure in the rodless chamber 512 drops instantaneously. As the thrust output by the loading piston 53 decreases instantaneously, the first high-pressure airbag 5121 also expands. This results in the second high-pressure airbag 5131 having a higher pressure than the first high-pressure airbag 5121. The second high-pressure airbag 5131 then forces the fluid from the rod chamber 513 through the damping hole 532 into the rodless chamber 512, prompting the fluid pressures in the rod chamber 513 and the rodless chamber 512 to reach equilibrium as quickly as possible.

[0049] By setting a unique high-pressure airbag and a second high-pressure airbag 5131, both the rodless chamber 512 and the rod chamber 513 can be filled with a mixture of gas and liquid, thereby increasing the compression ratio of the medium. This reduces rigid impact while realistically simulating the uphill and downhill conditions of a vehicle, and enables flexible adjustment of the pushing force of the loading cylinder 50.

[0050] Specifically, in combination Figures 5 to 7 Understandably, in this embodiment, the loading piston 53 has a liquid flow hole that runs vertically through it, and a liquid flow valve 90 is provided inside the liquid flow hole; wherein, the liquid flow valve 90 opens when the fluid pressure difference on both sides of the loading piston 53 is greater than a set threshold, and closes when the fluid pressure difference on both sides of the loading piston 53 is less than or equal to the set threshold.

[0051] If the damping orifice 532 is too large, it will lose its damping effect, affecting the realism of the instantaneous load change when a vehicle enters an uphill or downhill road from a level road. However, because the damping orifice 532 restricts the flow velocity of fluid between the rod chamber 513 and the rodless chamber 512, the process of restoring stability after a rapid load change is relatively slow. In actual working conditions, the load on the road surface quickly returns to a stable state after the vehicle enters an uphill or downhill road. Therefore, in this embodiment, a flow valve 90 is set on the loading piston 53 to increase the speed at which the fluid pressure in the rod chamber 513 and the rodless chamber 512 returns to equilibrium after an instantaneous change. The principle is as follows: The flow valve 90 is a normally closed valve that can open in both directions. Its opening and closing state depends on the fluid pressure difference between the rod chamber 513 and the rodless chamber 512. When the regulating element 70 drives the pressure regulating piston 52 downward, the fluid pressure in the rodless chamber 512 increases instantaneously, causing the pushing force of the loading piston 53 to increase instantaneously. When the fluid pressure in the rodless chamber 512 is higher than the fluid pressure in the rod chamber 513, and the difference between the two reaches a set threshold, the flow valve 90 opens. At this time, the fluid in the rodless chamber 512 can flow to the rod chamber 513 simultaneously through the flow valve 90 and the damping orifice 532, thereby increasing the pressure of the rod chamber. The fluid pressure balance speed of rodless chamber 513 and rodless chamber 512; conversely, when the regulating component 70 drives the pressure regulating piston 52 to move upward, the fluid pressure of rodless chamber 512 decreases instantaneously, causing the pushing force of loading piston 53 to decrease instantaneously. When the fluid pressure of rodless chamber 512 is lower than the fluid pressure of rod chamber 513, and the difference between the two reaches the set threshold, the flow valve 90 opens. At this time, the fluid in rod chamber 513 flows to rodless chamber 512 through flow valve 90 and damping orifice 532 to balance the fluid pressure. Compared with simply setting damping orifice 532, the fluid pressure balancing efficiency can be improved.

[0052] Optionally, in this embodiment, the structure of the flow valve 90 is as follows: Figure 6 and Figure 7 As shown, the flow valve 90 includes a valve body 91, a valve core 92, and two valve stems 924. The valve body 91 is embedded in the flow hole, and a valve hole 911 is provided through the center of the valve body 91 along its axial direction. The valve hole 911 includes a small diameter section 9111 and two large diameter sections 9112 located at both ends of the small diameter section 9111. The valve core 92 is slidably connected to the small diameter section 9111. A through hole 921 is provided at the center of the valve core 92, and an annular groove 922 is provided in the middle of the outer periphery of the valve core 92. The annular groove 922 and the through hole 921 are connected through a radial hole 923. The two valve stems 924 are fixedly connected in the two large diameter sections 9112 and are respectively inserted into the two ends of the through hole 921. The two valve stems 924 are respectively fitted with elastic members 925 that abut against the valve core 92.

[0053] Specifically, when the fluid pressure difference across the loading piston 53 is greater than a set threshold, the valve core 92 slides to the low-pressure side to the open state based on the pressure difference, overcoming the elastic force of the elastic element 925; when the fluid pressure difference across the loading piston 53 is equal to or less than the set threshold, the valve core 92 resets under the action of the elastic force of the elastic element 925 and remains in the closed state.

[0054] When the fluid pressure difference across the valve core 92 is equal to or lower than the set threshold, the axial force generated on the valve core 92 based on the fluid pressure difference is insufficient to overcome the elastic force of the elastic element 925, such as a spring. Therefore, the valve core 92 is in the neutral position and remains in the plugged state with the two valve stems 924, and the fluid cannot enter the through hole 921. When the fluid pressure difference is higher than the set threshold, the difference in fluid squeezing force on both sides of the valve core 92 is higher than the elastic force applied to it by the elastic element 925. Therefore, the valve core 92 will move axially toward the side with lower fluid pressure, thereby forming an open state in which the large-diameter section 9112 on the low-pressure side is connected to the annular groove 922 and the valve stem 924 on the high-pressure side is withdrawn from the through hole 921. At this time, the fluid on the high-pressure side enters the through hole 921 and enters the annular groove 922 through the radial hole 923 from the through hole 921, and then flows into the large-diameter section 9112 on the low-pressure side.

[0055] As the fluid continues to flow from the high-pressure side to the low-pressure side, the fluid pressure difference on both sides of the loading piston 53 gradually decreases. When the fluid pressure difference decreases to be equal to or less than the set threshold, the force exerted by the elastic element 925 on the valve core 92 is greater than the force exerted by the pressure difference, thereby causing the valve core 92 to slide to the middle position and re-form the closed state where the through hole 921 and the valve stems 924 on both sides are inserted.

[0056] This design utilizes the insertion and engagement of two valve stems 924 with the through hole 921 and the elastic force of the elastic element 925 on the valve core 92 to achieve switching based on changes in fluid pressure difference. This not only enables bidirectional opening but also features a simple, compact structure and high stability.

[0057] For example, such as Figure 5 As shown, the adjusting component 70 includes a rotary drive component 71, a rotating sleeve 72, and a drive rod 73; the rotary drive component 71 is fixedly connected to the outer wall of the cylinder body 51; the rotating sleeve 72 is rotatably connected to the center of the top wall of the cylinder body 51; one end of the drive rod 73 is connected to the pressure regulating piston 52, and the other end passes through the rotating sleeve 72 and is connected to the output end of the rotary drive component 71, and the drive rod 73 is threadedly engaged with the rotating sleeve 72.

[0058] The rotary drive component 71 can be a bidirectional drive motor, such as a servo motor or a stepper motor. The transmission connection between the rotary drive component 71 and the rotating sleeve 72 can be gear transmission. By rotating the rotating sleeve 72 through the rotary drive component 71, the threaded engagement between the rotating sleeve 72 and the drive rod 73 can drive the drive rod 73 to move axially, thereby driving the pressure regulating piston 52 to slide up and down within the cylinder 51. The driving method is stable and efficient, and the axial movement of the drive rod 73 can be controlled by controlling the rotation angle of the drive motor, thereby achieving accurate adjustment of the movement of the pressure regulating piston 52 and improving the adjustment accuracy of the pushing force output by the loading cylinder 50.

[0059] like Figure 5 As shown, considering that the air pressure of the first high-pressure airbag 5121 and the second high-pressure airbag 5131 determines the fluid pressure in the medium chamber 511 under normal conditions, the fluid pressure can be finely adjusted by changing the inflation volume of the first high-pressure airbag 5121 and the second high-pressure airbag 5131 (it is difficult to achieve a large adjustment). Therefore, in this embodiment, the first high-pressure airbag 5121 is connected to the top of the rodless chamber 512, i.e., the pressure regulating piston 52. The center of the drive rod 73 and the pressure regulating piston 52 are provided with a first inflation hole 5122 that communicates with the first high-pressure airbag 5121. A first air valve 5123 is provided in the first inflation hole 5122. The second high-pressure airbag 5131 is connected to the bottom of the rod chamber 513. A second inflation hole 5132 that communicates with the second high-pressure airbag 5131 is provided on the bottom wall of the cylinder 51. A second air valve 5133 is provided in the second inflation hole 5132.

[0060] In some embodiments, please refer to Figure 3 and Figure 4 The front and rear ends of the gantry frame 10 are provided with sliding grooves 12, and the front and rear ends of the support frame 20 are respectively slidably connected to the two sliding grooves 12. Each sliding groove 12 is provided with two pushers 121, which are located on both sides of the support frame 20. Each pusher 121 is provided with a pressure sensor 30 between it and the support frame 20.

[0061] The slidable connection of both ends of the support frame 20 to one of the slide grooves 12 ensures the connection stability of the support frame 20. After the pusher 121 forms a sliding constraint on the support frame 20, the lateral force exerted by the loading beam on the gantry frame 10 when the loading vehicle 60 passes through a curve can be detected by the corresponding pressure sensor 30. The pusher 121 can be a telescopic cylinder or an electric push rod. The pushing action of the pusher 121 can drive the support frame 20 to slide in the slide groove 12, thereby adjusting the position of the loading vehicle 60 in the road width direction to meet the loading test requirements at different locations on the road surface.

[0062] For example, such as Figure 4As shown, the aforementioned pusher 121 is a telescopic cylinder, and the output end of the telescopic cylinder is provided with an elastic support 122. The pressure sensor 30 is located between the elastic support 122 and the side wall of the support frame 20.

[0063] Specifically, the elastic support 122 can be a single-layer or multi-layer stacked disc spring. By setting the elastic support 122, the jacking member 121 can form a lateral elastic constraint on the support frame 20. This allows the support frame 20 to obtain a corresponding lateral displacement when the loading vehicle 60 sideslips due to centrifugal force exceeding lateral friction during a curve. Based on the detection value of the pressure sensor 30, the magnitude of the sliding friction between the tires and the road surface when the loading vehicle 60 sideslips can be calculated. Compared with the method of rigidly constraining the support frame 20, which can only obtain lateral static friction, obtaining lateral sliding friction by simulating the actual sideslip situation facilitates in-depth research on the relationship between road performance and vehicle cornering stability, and improves the comprehensiveness of data acquisition in accelerated loading tests.

[0064] It should be noted that, since the friction between the support frame 20 and the slide 12 has a significant impact on the lateral force test data, in order to improve the accuracy of the data, such as... Figure 4 As shown, in this embodiment, the upper and lower sides of the end of the support frame 20 that extends into the slide groove 12 are provided with roller rows 21, and each roller row 21 rolls against the groove wall of the slide groove 12. The roller rows 21 are composed of several rollers arranged sequentially along the extension direction of the slide groove 12. By setting the roller rows 21 to replace sliding friction with rolling friction, the influence of motion friction of the support frame 20 can be avoided to the greatest extent, thereby improving data reliability.

[0065] It should be understood that, based on the above embodiments, the loading device also includes a controller, which is electrically connected to the pressure sensor 30, the rotary drive component 71, the loading vehicle 60, and the jacking component 121, and is wirelessly connected to a remote industrial control computer.

[0066] It should be noted that the remote industrial control computer can be an industrial control computer set up in a central control room outside the test site. The controller and the remote industrial control computer can transmit signals through a wireless transmission module. These are very mature existing technologies and will not be described in detail here.

[0067] The pressure sensor 30 can feed its detection data back to the controller in real time, and the controller can then transmit the data wirelessly to a remote industrial control computer (so that the operator can monitor the lateral force data of the curve). The operator can send commands to the controller through the remote industrial control computer. Based on the control commands, the controller controls the rotary drive component 71, the loading vehicle 60, and the jacking component 121 to perform corresponding actions. The control commands should specifically include at least the speed of the loading vehicle 60, the rotation angle of the rotary drive component 71 (so as to adjust the up and down sliding amount of the pressure regulating piston 52, thereby controlling the load size and variation pattern), and the extension and retraction amount of the jacking component 121 (so as to control the position of the loading vehicle 60 in the width direction of the road surface).

[0068] Based on the same inventive concept, combined with Figures 1 to 7 It is understood that this application embodiment also provides a ring track accelerated loading test system, including a test ring track 80, a track 81 arranged along the test ring track 80, and the above-mentioned loading device.

[0069] Compared with the prior art, the ring track accelerated loading test system provided by the present invention adopts the above-mentioned loading device, which can use the detection value of pressure sensor 30 to feed back the data on the influence of road performance on sideslip during the cornering process of loading vehicle 60. At the same time, the adjusting component 70 is used to flexibly adjust the jacking force of loading cylinder 50 to simulate the scenario of loading vehicle 60 going up and down slope, further improving the comprehensiveness of data acquisition in the accelerated loading test.

[0070] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A loading device, characterized in that, include: The gantry frame has rail wheel sets on both sides, and the rail wheel sets on both sides are used to clamp and roll the rails on both sides of the test ring. The support frame is slidably connected to the middle of the gantry frame along the width direction of the test track, and pressure sensors are provided on both sides of the support frame and between the gantry frame; The load-bearing beam is hinged to the support frame on one side and connected to the support frame on the other side via a loading cylinder. The loading vehicle has a connecting beam in the middle, which is hinged to the middle of the load-sharing beam; The loading cylinder is used to push the load-equalizing beam so that the loading vehicle applies a load to the road surface of the test loop, and the loading cylinder has an adjusting component for flexibly adjusting its pushing force. The pressure sensor is used to detect the lateral force transmitted to the bearing frame when the loading vehicle turns a corner. The loading cylinder includes: The cylinder body is hinged to the outside of the support frame and is equipped with the adjusting component; A pressure regulating piston is slidably connected to the cylinder body and is drivenly connected to the adjusting component. The pressure regulating piston divides the interior of the cylinder body into a sealed medium cavity, which is filled with fluid. A loading piston is slidably connected within the medium cavity. The loading piston has a loading rod that extends downward through the cylinder and is hinged to the load-equalizing beam. The loading piston also has a damping hole that extends vertically through the cylinder. The adjusting component is used to drive the pressure regulating piston to move up and down to adjust the volume of the medium cavity, and the damping orifice is used to balance the fluid pressure on both sides of the loading piston. The loading piston divides the medium chamber into a rodless chamber and a rod chamber. The rodless chamber is provided with a first high-pressure airbag, and the rod chamber is provided with a second high-pressure airbag. The loading piston has a through-hole for fluid flow, and a fluid flow valve is provided inside the through-hole; wherein, the fluid flow valve opens when the fluid pressure difference on both sides of the loading piston is greater than a set threshold, and closes when the fluid pressure difference on both sides of the loading piston is less than or equal to the set threshold.

2. The loading device as described in claim 1, characterized in that, The flow valve includes: A valve body is fitted into the liquid flow hole. A valve hole is provided through the center of the valve body along its axial direction. The valve hole includes a small diameter section and two large diameter sections located at both ends of the small diameter section. A valve core is slidably connected to the small-diameter section. The valve core has a through hole at its center and an annular groove at the center of its outer periphery. The annular groove communicates with the through hole through a radial hole. Two valve stems are fixedly connected to the two large-diameter sections respectively, and are respectively inserted into the two ends of the through hole. Each of the two valve stems is fitted with an elastic element that abuts against the valve core. Specifically, when the fluid pressure difference across the loading piston is greater than the set threshold, the valve core slides to the low-pressure side to the open state based on the pressure difference, overcoming the elastic force of the elastic element; when the fluid pressure difference across the loading piston is equal to or less than the set threshold, the valve core resets and remains in the closed state under the action of the elastic force of the elastic element.

3. The loading device as described in claim 1, characterized in that, The adjusting element includes: A rotary drive component is fixedly connected to the outer wall of the cylinder body; A rotating sleeve is rotatably connected to the center of the top wall of the cylinder. The drive rod has one end connected to the pressure regulating piston and the other end passing through the rotating sleeve and being connected to the output end of the rotary drive component. The drive rod is threadedly engaged with the rotating sleeve.

4. The loading device as described in claim 1, characterized in that, The front and rear ends of the gantry frame are provided with sliding grooves, and the front and rear ends of the support frame are respectively slidably connected to the two sliding grooves. Each of the slides has two pushers arranged opposite each other, the two pushers are located on both sides of the support frame, and each pusher is provided with a pressure sensor between itself and the support frame.

5. The loading device as described in claim 4, characterized in that, The pushing component is a telescopic cylinder, and the output end of the telescopic cylinder is provided with an elastic support component. The pressure sensor is located between the elastic support component and the side wall of the support frame.

6. The loading device as described in claim 4, characterized in that, The bearing frame has rollers on both the upper and lower sides of the end that extends into the chute, and each roller rolls against the chute wall.

7. A ring-track accelerated loading test system, characterized in that, It includes a test loop, a track laid along the test loop, and a loading device as described in any one of claims 1-6.

Images