Linear acceleration loading vehicle

Abstract

The invention provides a linear acceleration loading vehicle which is driven by a linear motor to be used as one or more chain links of an endless chain to circularly run along an annular track, and comprises a frame, and a track wheel, a loading assembly, a loading wheel and an electromechanical conversion assembly which are connected to the frame, two sides of the frame are respectively provided with a driving plate and at least two groups of rail wheels, the driving plate is electromagnetically coupled with the output end of the linear motor, each group of rail wheels are rolled in the annular rail, the middle part of the frame is provided with a floating frame used for being connected with the loading wheel, and the floating frame is connected with the output end of the loading assembly; an electric adjusting piece is arranged on the loading assembly and is used for adjusting the output load of the loading assembly; the electromechanical conversion assembly is in transmission connection with at least one set of rail wheels and is electrically connected with the electric adjusting piece. The linear acceleration loading vehicle provided by the invention can monitor and adjust the loading force of the loading wheel on the test road surface in real time, thereby improving the simulation comprehensiveness and integrity of the road surface load working condition.

Description

Technical Field

[0001] The invention belongs to the technical field of road performance testing, and in particular relates to a linear acceleration loading vehicle. Background Art

[0002] Linear acceleration loading tests are used to comprehensively simulate the actual service conditions of pavement materials and structures in specific geographical environments. They are a primary method for scientific research on pavement structures, materials, and processes. Existing linear acceleration loading test systems primarily include linear reciprocating motion loading tests and continuous cyclic loading tests based on circular tracks. The latter offers significant advantages over reciprocating motion loading in terms of operational continuity and test efficiency.

[0003] The main operating principle of existing cyclic loading test systems is that a loading vehicle and chain links form a chain structure. The wheels on the loading vehicle and each link operate continuously based on the constraints of the circular track. The magnetic plates on the loading vehicle and chain links work with linear motors to form electromagnetic coupling to generate driving force. A drawback of existing loading test systems is that the contact pressure between the loading vehicle and the road surface, i.e., the loading force, must be applied only when the chain is stopped. This makes it impossible to accurately simulate conditions where the road load frequently changes, thus affecting the authenticity of the accelerated loading test data. Furthermore, due to the significant energy loss and time required to start and stop the system, this system is not conducive to cost control and efficiency improvement. Summary of the Invention

[0004] An embodiment of the present invention provides a linear acceleration loading vehicle, which aims to improve the simulation authenticity of road load conditions and promote energy saving and efficiency improvement of linear acceleration loading tests.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: to provide a linear acceleration loading vehicle, which is used to circulate along a circular track as one or more links of a circular chain under the drive of a linear motor, and includes a frame, and rail wheels, a loading assembly, a loading wheel and an electromechanical conversion assembly connected to the frame; a drive plate and at least two sets of rail wheels are respectively provided on both sides of the frame, the drive plate is electromagnetically coupled with the output end of the linear motor, and each set of rail wheels rolls in the circular track, and a floating frame for connecting the loading wheel is provided in the middle of the frame, and the floating frame is connected to the output end of the loading assembly; an electric adjustment member is provided on the loading assembly, and the electric adjustment member is used to adjust the output load of the loading assembly; the electromechanical conversion assembly is transmission-connected to at least one set of rail wheels, and is electrically connected to the electric adjustment member.

[0006] In one possible implementation, the loading assembly includes a telescopic cylinder and an oil storage tank; one end of the telescopic cylinder is connected to the vehicle frame, and the other end is connected to the floating frame; a piston is provided inside the oil storage tank and has an oil chamber whose volume changes based on the movement of the piston, and the oil chamber is connected to the telescopic cylinder through an oil circuit, and a pressure sensor is provided on the oil circuit; the pressure sensor is used to feed back the oil pressure signal to the system controller, the electric adjustment member is connected to the oil storage tank and to the piston, and the electric adjustment member is controlled by the system controller.

[0007] In some embodiments, a sensing baffle is provided on the floating frame, and a displacement sensor is provided on the vehicle frame. The sensing end of the displacement sensor is aligned with the sensing baffle. The displacement sensor is used to detect the floating amount of the sensing baffle and feed back the detection value to the system controller.

[0008] Exemplarily, the electric adjustment component includes a drive motor, a sleeve and a transmission rod; the sleeve is rotatably connected to the oil storage tank and is located on the side of the piston facing away from the oil chamber; the transmission rod passes through the sleeve and is connected to the piston, and the transmission rod is threadedly engaged with the sleeve; the drive motor is connected to the oil storage tank and the output end is transmission-connected to the sleeve, and the drive motor is electrically connected to the electromechanical conversion assembly.

[0009] For example, a buffer airbag extending into the oil cavity is connected to the oil tank, and the buffer airbag has an inflation valve extending out of the oil tank.

[0010] In some embodiments, the floating frame includes two cantilever beams, one end of the cantilever beams is hinged to the frame, and the other end is hinged to the telescopic cylinder. The middle parts of the two cantilever beams are commonly connected to the loading shaft, and the loading wheel is rotatably connected to the loading shaft and is located between the two cantilever beams; wherein, two buffer blocks are provided on the frame, and the two buffer blocks are respectively supported on the ends of the two cantilever beams connected to the telescopic cylinder.

[0011] In one possible implementation, the electromechanical conversion assembly includes a driving pulley, a passive pulley, a first transmission belt and a generator; the generator is connected to the frame and the power input end is connected to the passive pulley, the driving pulley is coaxially connected to one set of rail wheels and is connected to the passive pulley through the first transmission belt; the generator is electrically connected to the electric adjustment member.

[0012] In some embodiments, each set of rail wheels includes a first wheel body and a second wheel body that are coaxially connected and rotate in opposite directions; the first wheel body is used to roll the inner rail of the circular track, and the second wheel body is used to roll the outer rail of the circular track; wherein, the driving pulley is coaxially connected to the first wheel body; the electromechanical conversion assembly also includes a reverse transmission assembly, and the second wheel body is connected to the driven pulley through the reverse transmission assembly.

[0013] Exemplarily, the reverse transmission assembly includes a driving gear and a reverse gear; the driving gear is coaxially connected to the second wheel body, and the reverse gear is rotationally connected to the frame and meshed with the driving gear; wherein the wheel side of the reverse gear is coaxially connected to the first transmission wheel, the wheel side of the driven pulley is coaxially connected to the second transmission wheel, and the first transmission wheel and the second transmission wheel are connected by a second transmission belt.

[0014] For example, there are two connecting shafts spaced apart on both sides of the frame, a rigid link is hinged on one of the connecting shafts, and a flexible link is hinged on the other connecting shaft, and the rigid link and the flexible link are respectively hinged to one of the links of the chain; the connection length of the rigid link, the connection length of the flexible link, and the spacing between the two connecting shafts are all consistent with the pitch of the chain.

[0015] The beneficial effect of the linear acceleration loading vehicle provided by the present invention is that: compared with the prior art, the linear acceleration loading vehicle of the present invention serves as one or more links of the endless chain, and cooperates with the endless track through the rail wheels on both sides of the frame, thereby being able to continuously circulate along the endless track under the electromagnetic coupling driving force of the linear motor on the drive plate. During operation, the electromechanical conversion component can convert the rotational mechanical energy of at least one set of rail wheels into electrical energy, thereby meeting the power demand of the electric adjustment part. The electric adjustment part can adjust the load applied by the loading component to the floating frame, so that the loading force of the loading wheel installed on the floating frame on the test road surface can be flexibly adjusted under normal operation of the endless chain, so that the test road surface can obtain a constantly changing load, which can not only improve the simulation authenticity of the road load working condition, thereby improving the reliability of the linear acceleration loading test data, but also save the huge energy consumption and time cost caused by the start and stop of the system, thereby achieving energy saving and efficiency improvement of the linear acceleration loading test. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the three-dimensional structure of a linear acceleration loading vehicle provided in an embodiment of the present invention; Figure 2 A schematic diagram of the operating state of a linear acceleration loading vehicle provided by an embodiment of the present invention; Figure 3 Schematic diagram of the coordination structure between the rail wheel and the annular track in an embodiment of the present invention; Figure 4 A schematic structural diagram of a loading component used in an embodiment of the present invention; Figure 5 A schematic diagram of the internal structure of an oil storage tank used in an embodiment of the present invention; Figure 6 A schematic diagram of the three-dimensional structure of a vehicle frame used in an embodiment of the present invention; Figure 7 for Figure 6 Schematic diagram of the local enlarged structure at A in the middle; Figure 8 A schematic structural diagram of an electromechanical conversion assembly used in an embodiment of the present invention; Figure 9 This is a schematic structural diagram of the flexible connecting rod used in an embodiment of the present invention.

[0017] In the figure: 10, chain; 20, circular track; 21, inner rail; 22, outer rail; 30, frame; 31, drive plate; 32, floating frame; 321, cantilever beam; 322, loading shaft; 33, induction baffle; 34, displacement sensor; 35, buffer block; 36, connecting shaft; 37, rigid connecting rod; 38, flexible connecting rod; 381, fixed sleeve; 382, pull rod shaft; 383, rubber body; 384, limit plate; 40, rail wheel; 41, first wheel body; 42, second wheel body; 50, loading assembly; 500, electric adjustment member; 501, drive motor; 502, screw sleeve; 503, transmission Rod; 504, first gear; 505, second gear; 51, telescopic cylinder; 52, oil storage tank; 521, piston; 522, oil chamber; 523, cushioning airbag; 5231, inflation valve; 53, oil circuit; 531, pressure sensor; 60, loading wheel; 70, electromechanical conversion assembly; 71, driving pulley; 72, driven pulley; 73, first transmission belt; 74, generator; 75, reverse transmission assembly; 751, driving gear; 752, reverse gear; 753, first transmission wheel; 754, second transmission wheel; 755, second transmission belt; 80, linear motor; 90, test road surface. DETAILED DESCRIPTION

[0018] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0019] It should be noted that when an element is referred to as being "disposed on" or "connected to" another element, it may be directly on the other element or indirectly on the other element. It should be understood that the terms "upper", "lower", "inner", "outer", etc., indicating the orientation or positional relationship, are 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, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. The terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. In the description of this application, "multiple" and "several" mean two or more, unless otherwise clearly and specifically defined.

[0020] Please also refer to Figures 1 to 9The linear acceleration loading vehicle provided by the present invention is now described. The linear acceleration loading vehicle is used to circulate along the circular track 20 as one or more links of the endless chain 10 under the drive of a linear motor 80. The linear acceleration loading vehicle includes a frame 30, and rail wheels 40, a loading assembly 50, a loading wheel 60, and an electromechanical conversion assembly 70 connected to the frame 30. A drive plate 31 and at least two sets of rail wheels 40 are respectively provided on both sides of the frame 30. The drive plate 31 is electromagnetically coupled to the output end of the linear motor 80. Each set of rail wheels 40 rolls within the circular track 20. A floating frame 32 for connecting to the loading wheel 60 is provided in the middle of the frame 30. The floating frame 32 is connected to the output end of the loading assembly 50. The loading assembly 50 is provided with an electric adjustment member 500 for adjusting the output load of the loading assembly 50. The electromechanical conversion assembly 70 is transmission-connected to at least one set of rail wheels 40 and electrically connected to the electric adjustment member 500.

[0021] It should be noted that, in this embodiment, the endless chain 10 is a closed-loop structure having two straight sections, an upper and a lower section. When the loading wheel 60 moves to the lower straight section of the endless chain 10, it rolls on the test road surface 90. The role of the annular track 20 is, on the one hand, to provide running trajectory constraints for each link of the endless chain 10 and the loading vehicle, and on the other hand, to provide a reaction force for the loading vehicle to ensure that the loading vehicle can apply sufficient loading force to the test road surface 90 in the lower straight section.

[0022] It should be understood that the linear motor 80 is an electric drive device that directly converts electrical energy into linear motion mechanical energy. Its working principle is the law of electromagnetic induction. In this embodiment, the cooperation between the drive plate 31 and the linear motor 80 can be as follows: Figure 3 As shown, the drive plate 31 adopts a magnetic conductive plate such as a copper plate or an aluminum plate. The drive plate 31 extends into the air gap of the linear motor 80. When the linear motor 80 is energized to generate an alternating magnetic field, the drive plate 31 acts as a secondary to generate electromagnetic coupling with the alternating magnetic field to obtain an electromagnetic driving force in a linear direction, thereby driving the frame 30 to run along the circular track 20. It should be noted that in this embodiment, the drive plates 31 are provided on both sides of the frame 30 to ensure that the force on the frame 30 is balanced. At the same time, the drive plates 31 can also be provided on each link of the chain 10 to ensure that the chain 10 as a whole is subjected to a stable and sufficient driving force.

[0023] In this embodiment, the electromechanical conversion component 70 refers to a component that can convert mechanical energy into electrical energy. Specifically, the electromechanical conversion component 70 obtains rotational mechanical energy by connecting to at least one set of rail wheels 40. The rotational mechanical energy is converted into electrical energy and then transmitted to the electric adjustment component 500, thereby meeting the power supply needs of the loading vehicle during its continuous movement along the circular track 20.

[0024] In this embodiment, the function of the loading assembly 50 is to provide a supporting force for the floating frame 32. When the loading wheel 60 rolls and contacts the test road surface 90, a reaction force is generated on the floating frame 32. When the reaction force exceeds the supporting force of the loading assembly 50, the floating frame 32 will swing upward until the two are balanced. Therefore, the output load of the loading assembly 50 on the floating frame 32 is proportional to the loading force of the loading wheel 60 on the test road surface 90; the function of the electric adjustment member 500 is to adjust the output load of the loading assembly 50, thereby realizing the adjustment of the contact pressure between the loading wheel 60 and the test road surface 90, that is, the loading force adjustment.

[0025] Compared with the prior art, the linear acceleration loading vehicle provided in this embodiment is one or more links of the endless chain 10. The linear acceleration loading vehicle cooperates with the circular track 20 through the rail wheels 40 on both sides of the frame 30, thereby being able to continuously circulate along the circular track 20 under the electromagnetic coupling driving force of the linear motor 80 on the drive plate 31. During operation, the electromechanical conversion component 70 can convert the rotational mechanical energy of at least one set of rail wheels 40 into electrical energy, thereby meeting the power demand of the electric adjustment member 500. The electric adjustment member 500 can adjust the load applied by the loading component 50 to the floating frame 32, thereby being able to flexibly adjust the loading force of the loading wheel 60 installed on the floating frame 32 on the test road surface 90 under normal operation of the endless chain 10, so that the test road surface 90 can obtain a continuously changing load, which can not only improve the simulation authenticity of the road load working condition, thereby improving the reliability of the linear acceleration loading test data, but also save the huge energy consumption and time cost caused by the start and stop of the system, thereby achieving energy saving and efficiency improvement of the linear acceleration loading test.

[0026] As a specific implementation of the above-mentioned loading component 50, please combine Figure 1 、 Figure 4 and Figure 5 It is understood that the loading assembly 50 includes a telescopic cylinder 51 and an oil storage tank 52; one end of the telescopic cylinder 51 is connected to the vehicle frame 30, and the other end is connected to the floating frame 32; a piston 521 is provided inside the oil storage tank 52 and has an oil chamber 522 whose volume changes based on the movement of the piston 521, and the oil chamber 522 is connected to the telescopic cylinder 51 through an oil circuit 53, and a pressure sensor 531 is provided on the oil circuit 53; the pressure sensor 531 is used to feed back the oil pressure signal to the system controller, the electric adjustment component 500 is connected to the oil storage tank 52 and to the piston 521, and the electric adjustment component 500 is controlled by the system controller.

[0027] Here, the telescopic cylinder 51 outputs thrust to the floating frame 32, which in turn transmits the load to the loading wheel 60 via the floating frame 32. When the loading wheel 60 contacts the test surface 90 and transmits a reaction force to the floating frame 32, causing the telescopic cylinder 51 to retract, hydraulic oil flows through the oil passage 53 into the oil chamber 522 until the oil pressure in the telescopic cylinder 51 and the oil chamber 522 reach equilibrium. At this point, the oil pressure directly reflects the thrust of the telescopic cylinder 51 on the floating frame 32, and thus the loading force of the loading wheel 60 on the test surface 90. Therefore, a pressure sensor 531 connected to the oil passage 53 monitors the oil pressure in real time and feeds the monitoring data back to the system controller (the system controller can be the controller of the entire linear acceleration loading system, or a separate controller can be provided on the loading vehicle to establish a wireless transmission connection with the system controller. The pressure sensor 531 feeds the monitoring data back to the separate controller of the loading vehicle, which then transmits the monitoring data to the system controller via wireless signal transmission). The system controller can actively or passively control the movement of the electric adjustment member 500 based on commands input by the operator.

[0028] Specifically, when conducting a constant load test, if the oil pressure monitoring data received by the system controller exceeds the set range, it is necessary to issue an adjustment instruction to the electric adjustment component 500. For example, when the oil pressure monitoring data is higher than the set range, it can be determined that the load applied by the loading wheel 60 to the test road surface 90 is too large, and the system controller should control the electric adjustment component 500 to drive the piston 521 to move so that the volume of the oil chamber 522 increases, thereby reducing the oil pressure, and then adjusting the load applied by the loading wheel 60 to the test road surface 90 to within the target range; conversely, when the oil pressure monitoring data is lower than the set range, the electric adjustment component 500 drives the piston 521 to move so that the volume of the oil chamber 522 decreases, thereby restoring the oil pressure to within the set range. Through the real-time monitoring of the above-mentioned pressure sensor 531 and the adaptive adjustment of the electric adjustment component 500, the data accuracy and reliability of the constant load loading test on the test road surface 90 are improved.

[0029] When conducting a variable load test, corresponding control instructions can be entered into the system controller, and the action of the electric adjustment component 500 can be controlled based on the control instructions. For example, when the oil pressure monitoring data is in the first interval and has been running for a first period of time, the system controller controls the electric adjustment component 500 to drive the piston 521 to move and adjust the oil pressure to the second interval. After the oil pressure remains in the second interval and moves for a second period of time, the electric adjustment component 500 drives the piston 521 to move again and adjusts the oil pressure back to the first interval. Repeating this process can simulate the working condition where the loading wheel 60 continuously applies an alternating loading force to the test road surface 90. Of course, the loading force change intervals are not limited to two, and can also be changed in an orderly or random manner within more intervals. These can all be achieved through different instructions entered into the system controller.

[0030] It should be noted that the control strategies or logics used by the above-mentioned system controller to control the action of the electric adjustment member 500 based on the control instructions are conventional and commonly used technical means in automation control and will not be described in detail here.

[0031] In some embodiments, see Figure 6 An inductive baffle 33 is provided on the floating frame 32, and a displacement sensor 34 is provided on the vehicle frame 30. The sensing end of the displacement sensor 34 is aligned with the inductive baffle 33. The displacement sensor 34 is used to detect the floating amount of the inductive baffle 33 and feed back the detection value to the system controller.

[0032] The displacement sensor 34 can monitor in real time the floating amount of the baffle as it moves up and down with the floating frame 32. Since the loading wheel 60 contacts the test road surface 90 only when it moves to the lower straight section of the chain 10, the floating frame 32 is subjected to the reaction force and floats upward. The electric adjustment member 500 adjusts the volume of the oil chamber 522 only when the loading wheel 60 contacts the test road surface 90. When the loading wheel 60 moves to the other positions of the chain 10, the loading wheel 60 is in an unloaded state. At this time, the telescopic cylinder 51 can automatically extend and retract under the action of the oil pressure to drive the floating frame 32 to reset. During this process, the hydraulic oil in the oil chamber 522 flows into The telescopic oil cylinder 51 is used to balance the pressure, so the oil pressure will decrease (below the set range), which will affect the system controller's accurate judgment of the oil pressure during the loading process. Therefore, setting a displacement sensor 34 to detect the floating amount of the floating frame 32 allows the system controller to judge the position of the loading wheel 60. Specifically, when the displacement sensor 34 detects that the floating amount of the floating frame 32 exceeds the target value, it can be determined that the loading wheel 60 begins to contact the test road surface 90. Based on this as a prerequisite, the action of the electric adjustment component 500 is controlled based on the oil pressure monitoring data of the pressure sensor 531, thereby ensuring that the adjustment logic of the loading force is clear and accurate.

[0033] It should be noted that the system controller can control the electric adjustment component 500 during the process of the loading vehicle contacting the test road surface 90, or when the loading vehicle is in an unloaded state, that is, when the floating amount data detected by the displacement sensor 34 determines that the loading vehicle has left the test road surface 90, the electric adjustment component 500 is controlled to drive the piston 521 to move to adjust the oil pressure, thereby adjusting the loading force when the loading wheel 60 contacts the test road surface 90 next time. The advantage of this adjustment method is that when the loading wheel 60 is in an unloaded state, the movement resistance of the piston 521 can be reduced, thereby reducing the power requirement for the electric adjustment component 500, which is conducive to improving the smoothness of the adjustment.

[0034] For some possible implementations, see Figure 5The above-mentioned electric adjustment component 500 includes a drive motor 501, a sleeve 502 and a transmission rod 503; the sleeve 502 is rotatably connected to the oil storage tank 52 and is located on the side of the piston 521 away from the oil chamber 522; the transmission rod 503 passes through the sleeve 502 and is connected to the piston 521, and the transmission rod 503 is threadedly engaged with the sleeve 502; the drive motor 501 is connected to the oil storage tank 52 and the output end is transmission-connected to the sleeve 502, and the drive motor 501 is electrically connected to the electromechanical conversion component 70.

[0035] The driving motor 501 drives the screw sleeve 502 to rotate forward, which can drive the transmission rod 503 to penetrate into the interior of the oil storage tank 52 along the axial direction of the screw sleeve 502, thereby driving the piston 521 to compress the oil chamber 522. When the oil pressure needs to be lowered, the driving motor 501 drives the screw sleeve 502 to reverse. At this time, the transmission rod 503 moves along the axial direction of the screw sleeve 502 toward the direction away from the oil chamber 522, thereby driving the piston 521 to move in the opposite direction to increase the volume of the oil chamber 522. Here, the transmission rod 503 and the screw sleeve 502 are threadedly matched to drive the piston 521 to move. Not only is the structure simple and compact, but it can also convert a relatively small rotational driving force into a relatively large axial movement force, which is beneficial to reducing the rated power requirements of the driving motor 501.

[0036] Specifically, such as Figure 5 As shown, the screw sleeve 502 is fitted with a first gear 504, and the motor shaft of the drive motor 501 is fitted with a second gear 505, which is meshed with the first gear 504. The first gear 504 has more teeth than the second gear 505, thereby achieving a deceleration and torque increase effect, further reducing the rated power requirement of the drive motor 501. At the same time, it can also meet the offset requirement of the drive motor 501 relative to the transmission rod 503, preventing the drive motor 501 from affecting the axial movement of the transmission rod 503.

[0037] It should be noted that if Figure 5As shown, the oil storage tank 52 is connected to a buffer air bag 523 extending into the oil cavity 522 , and the buffer air bag 523 has an inflation valve 5231 extending out of the oil storage tank 52 . In this case, it is taken into consideration that the loading wheel 60 changes from an unloaded state to a loaded state when it moves along the endless chain 10 to contact the test road surface 90. Therefore, the floating frame 32 and the loading assembly 50 will be subjected to a large instantaneous impact force. This situation is very detrimental to the service life of the floating frame 32 and the loading assembly 50. Therefore, in this embodiment, a buffer air bag 523 is provided inside the oil chamber 522. When the hydraulic cylinder is impacted at the moment the loading wheel 60 contacts the test road surface 90, the oil pressure increases. At this time, the hydraulic oil in the hydraulic cylinder enters the oil chamber 522 through the oil passage 53 and squeezes the buffer air bag 523. The buffer air bag 523 contracts under the action of the external oil pressure, thereby increasing the space in the oil chamber 522 for accommodating the hydraulic oil, thereby avoiding excessive instantaneous increase in oil pressure and causing excessive impact on the hydraulic cylinder. At the same time, it can also enable the floating frame 32 to have a certain amount of flexible floating when the loading wheel 60 contacts the test road surface 90, thereby avoiding damage to the floating frame 32 due to rigid impact force.

[0038] Specifically, nitrogen can be injected into the interior of the buffer airbag 523 through the inflation valve 5231. The inflation pressure of the buffer airbag 523 should be equal to the oil pressure in the oil chamber 522 when the loading wheel 60 loads and rolls the test road surface 90. In this way, the oil pressure in the oil chamber 522 can be restored to the set range after the loading wheel 60 stably contacts the test road surface 90, thereby ensuring that the loading force is sufficient and stable.

[0039] For some examples, see Figure 6 The above-mentioned floating frame 32 includes two cantilever beams 321, one end of the cantilever beam 321 is hinged to the frame 30, and the other end is hinged to the telescopic cylinder 51. The middle parts of the two cantilever beams 321 are commonly connected to the loading shaft 322, and the loading wheel 60 is rotatably connected to the loading shaft 322 and is located between the two cantilever beams 321; wherein, two buffer blocks 35 are provided on the frame 30, and the two buffer blocks 35 are respectively supported on the ends of the two cantilever beams 321 connected to the telescopic cylinder 51.

[0040] The two cantilever beams 321 distributed at intervals can form a space therebetween that can accommodate the loading wheel 60. At the same time, the cantilever beam 321 is hinged to the frame 30 at one end and suspended and hinged to the telescopic cylinder 51 at the other end. The telescopic cylinder 51 can apply a thrust to the suspended end of the cantilever beam 321, so that the loading wheel 60 connected to the middle part of the cantilever beam 321 applies a load to the test road surface 90. On the one hand, this connection method can ensure that the cantilever beam 321 has at least one fixed force point, thereby improving the load capacity of the cantilever beam 321. On the other hand, it can amplify the thrust force transmitted to the loading wheel 60 by the telescopic cylinder 51 through the cantilever beam 321 based on the leverage effect, which is conducive to reducing the cylinder diameter of the telescopic cylinder 51, thereby reducing the installation space requirement of the telescopic cylinder 51 and improving the compactness of the overall structure.

[0041] The above-mentioned buffer block 35 can specifically be a rubber block. In the initial state, the suspended end of the cantilever beam 321 is pressed against the buffer block 35 under the pushing action of the telescopic cylinder 51. When the loading wheel 60 contacts the test road surface 90, the suspended end of the cantilever beam 321 floats upward based on the reaction force and compresses the telescopic cylinder 51. At this time, the suspended end of the cantilever beam 321 is separated from the buffer block 35. When the loading wheel 60 passes the test road surface 90 and changes to an unloaded state, the cantilever beam 321 swings in the opposite direction under the pushing force of the telescopic cylinder 51 and is pressed against the buffer block 35 again, thereby ensuring the connection stability of the cantilever beam 321 and the frame 30 in the unloaded state. The role of the buffer block 35 is to prevent the cantilever beam 321 from rigidly colliding with the frame 30 and affecting its service life, while reducing operating noise.

[0042] Specifically, as an optional embodiment of the electromechanical conversion component 70, please refer to Figure 8 The electromechanical conversion assembly 70 includes a driving pulley 71, a passive pulley 72, a first transmission belt 73 and a generator 74; the generator 74 is connected to the frame 30 and the power input end is connected to the passive pulley 72, the driving pulley 71 is coaxially connected to one set of rail wheels 40 and is connected to the passive pulley 72 through the first transmission belt 73; the generator 74 is electrically connected to the electric adjustment member 500.

[0043] The function of the electromechanical conversion component 70 is to convert mechanical energy into electrical energy for use by the electric adjustment component 500, thereby achieving self-power supply, thereby solving the power demand of the electric adjustment component 500 that moves continuously with the frame 30. Moreover, since the linear acceleration loading system usually weighs tens of tons and the power consumption of the electric adjustment component 500 is relatively small, the operating resistance caused by the electromechanical conversion component 70 to the rail wheel 40 is almost negligible. Compared with the common method of obtaining electrical energy by using a slip ring to contact the power supply loop, it can greatly reduce the overall system cost and reduce the operating failure rate.

[0044] During the operation of the system, the rail wheel 40 rolls on the annular track 20 to obtain rotational power. At this time, the driving pulley 71 rotating with the rail wheel 40 drives the passive pulley 72 to rotate through the first transmission belt 73, so that the generator 74 obtains rotational mechanical energy. The generator 74 then converts the rotational mechanical energy into electrical energy and transmits it to the electric adjustment component 500, thereby ensuring that the electric adjustment component 500 can operate at any time and realize flexible adjustment of the output load of the loading component 50.

[0045] It should be understood here that, considering that the electric adjustment component 500 does not operate continuously but operates selectively based on control instructions, a battery can be set on the frame 30 in this embodiment, the generator 74 is electrically connected to the battery, and the battery is electrically connected to the electric adjustment component 500, so that under normal circumstances, the battery can be charged by the generator 74 and power can be supplied to the electric adjustment component 500 through the battery.

[0046] Furthermore, an electromagnetic clutch can be provided between the generator 74 and the driven pulley 72. The electromagnetic clutch is electrically connected to the system controller and powered by a battery. At the same time, a power detection module is provided on the battery. When the power detection module detects that the battery is fully charged, the system controller controls the electromagnetic clutch to disconnect. At this time, the generator 74 stops running, thereby reducing the resistance of the rail wheel 40, which is conducive to reducing operating energy consumption. When the power detection module detects that the battery power is lower than the set value, the system controller controls the electromagnetic clutch to close, so that the generator 74 starts to generate electricity and charge the battery. In addition, the provision of a battery is also conducive to providing continuous and stable power supply to the above-mentioned pressure sensor 531 and stroke sensor, thereby ensuring the continuity of pressure monitoring and floating monitoring.

[0047] It is important to understand that Figure 8 In this embodiment, each set of rail wheels 40 includes a first wheel body 41 and a second wheel body 42 that are coaxially connected and rotate in opposite directions; the first wheel body 41 is used to roll the inner rail 21 of the annular track 20, and the second wheel body 42 is used to roll the outer rail 22 of the annular track 20; wherein, the driving pulley 71 is coaxially connected to the first wheel body 41; the electromechanical conversion assembly 70 also includes a reverse transmission assembly 75, and the second wheel body 42 is connected to the driven pulley 72 through the reverse transmission assembly 75.

[0048] Considering that the annular track 20 needs to form a bilateral constraint on the rail wheel 40, the annular track 20 is composed of an inner rail 21 and an outer rail 22 arranged around the outer circumference of the inner rail 21, and the rail wheel 40 needs to roll the inner rail 21 and the outer rail 22 at the same time to eliminate the motion gap, thereby ensuring the operation stability. However, the direction of passive rotation of the rail wheel 40 when rolling the inner rail 21 is opposite to the direction of passive rotation when rolling the outer rail 22. Therefore, the rail wheel 40 is set to two independently rotatable first wheel bodies 41 and second wheel bodies 42. The first wheel body 41 rolls the inner rail 21, and the second wheel body 42 rolls the outer rail 22, thereby ensuring the constraint stability of the annular track 20 on the rail wheel 40.

[0049] Since the inner rail 21 mainly provides reaction force to the roller when the loading wheel 60 follows the endless chain 10 to contact the test road surface 90, and the inner rail 21 mainly provides support force to the rail wheel 40 when it reaches the unloaded state of the upper straight section, the contact pressure between the first wheel body 41 and the inner rail 21 is always higher than the contact pressure between the second wheel body 42 and the outer rail 22. Therefore, the rotational stability of the first wheel body 41 is higher than that of the second wheel body 42. Therefore, it is chosen here to coaxially fix the drive pulley 71 and the first wheel body 41, thereby improving the power input stability of the engine and thus improving the electromechanical conversion stability.

[0050] Of course, in order to further improve the working stability of the electromechanical conversion assembly 70 , the second wheel 42 is used to cooperate with the reverse transmission assembly 75 to transmit rotational mechanical energy to the generator 74 simultaneously with the first wheel 41 .

[0051] For example, combined Figure 8 It is understood that the above-mentioned reverse transmission assembly 75 includes a driving gear 751 and a reverse gear 752; the driving gear 751 is coaxially connected to the second wheel body 42, and the reverse gear 752 is rotatably connected to the frame 30 and meshed with the driving gear 751; wherein, the wheel side of the reverse gear 752 is coaxially connected to the first transmission wheel 753, and the wheel side of the driven pulley 72 is coaxially connected to the second transmission wheel 754, and the first transmission wheel 753 and the second transmission wheel 754 are connected by a second transmission belt 755.

[0052] By utilizing the reverse property of the external meshing gear transmission, the driving gear 751 rotates in the same direction as the second wheel body 42, and the reverse gear 752, driven by the driving gear 751, will form the same direction as the first wheel body 41. Then, the first transmission wheel 753, which rotates synchronously with the reverse gear 752, transmits the rotational mechanical energy to the second transmission wheel 754 through the second transmission belt 755, so that the generator 74 obtains the rotational mechanical energy from the second wheel body 42 synchronously.

[0053] It should be understood that the product of the transmission ratio of the above-mentioned driving gear 751 and the reverse gear 752 and the transmission ratio of the first transmission wheel 753 and the second transmission wheel 754 is equal to the transmission ratio of the driving pulley 71 and the driven pulley 72, thereby ensuring that the rotational mechanical energy transmitted to the generator 74 by the first wheel body 41 and the second wheel body 42 is consistent, avoiding interference between the two power routes.

[0054] Please note that Figure 6 and Figure 9 In this embodiment, two connecting shafts 36 are spaced apart on both sides of the frame 30, one of the connecting shafts 36 is hinged with a rigid link 37, and the other connecting shaft 36 is hinged with a flexible link 38, and the rigid link 37 and the flexible link 38 are respectively hinged to one of the links of the endless chain 10; the connection length of the rigid link 37, the connection length of the flexible link 38, and the spacing between the two connecting shafts 36 are all consistent with the pitch of the endless chain 10.

[0055] Normally, the frame 30 cannot match the size of a single link due to the installation space requirement of the loading wheel 60. Therefore, the frame 30 as a whole is equivalent to the combination of three links of the endless chain 10, that is, the rigid link 37 and the flexible link 38 each serve as a link, and the two connecting shafts 36 also serve as a link. This ensures that the frame 30 can turn smoothly with the endless chain 10, while ensuring that the frame 30 has sufficient space for installing the loading wheel 60.

[0056] Considering the stability of the operation of the link chain 10, it needs to have a certain tensioning force. However, considering that the processing and assembly errors of the link chain 10 affect the consistency of the chain link pitch, the link chain 10 is prone to chain jamming failure when in a tensioned state. Especially for a linear acceleration loading vehicle, as multiple chain links, it is more likely to get stuck during cornering and steering. Therefore, the flexible link 38 is used here to provide flexible expansion and contraction between the frame 30 and the corresponding chain link, thereby eliminating the difference in the pitch of each chain link and improving the stability and smoothness of the operation of the link chain 10.

[0057] Specifically, such as Figure 9 As shown, the above-mentioned flexible connecting rod 38 includes a fixed sleeve 381, a pull rod shaft 382 and two rubber bodies 383; wherein, one end of the fixed sleeve 381 is hinged to one of the connecting shafts 36, one end of the pull rod shaft 382 extends into the interior of the fixed sleeve 381 and has a slider, the slider slides with the fixed sleeve 381, and the other end of the pull rod shaft 382 is hinged to the chain link adjacent to the frame 30; the two rubber bodies 383 are arranged in the fixed sleeve 381 and are respectively located on both sides of the slider, and the two rubber bodies 383 are respectively in contact with the two limit plates 384 arranged in the fixed sleeve 381.

[0058] The two rubber bodies 383 form abutment on both sides of the slider, which not only ensures that the fixed sleeve 381 and the pull rod shaft 382 have sufficient tensile strength, but also enables the pull rod shaft 382 and the fixed sleeve 381 to obtain a certain elastic expansion and contraction, thereby eliminating the influence of the difference in chain link pitch on the smooth operation of the chain 10, thereby avoiding the chain jamming phenomenon and improving the operation stability of the linear acceleration loading test.

[0059] It should be noted that the linear acceleration loading vehicle provided in this embodiment can be used for single-axis single-wheel loading tests, single-axis dual-wheel loading tests, and multi-axis loading tests. Specifically, the loading shaft 322 is provided with flanges that can accommodate single and dual wheels, thereby meeting the requirements of single-axis single-wheel loading tests and single-axis dual-wheel loading tests. The two vehicle frames 30 can be connected via a fixed link and a flexible link 38 to form a biaxial structure. More than two vehicle frames 30 can also be connected sequentially via fixed links and flexible links 38. Of course, under normal circumstances, multi-axis loading tests typically do not exceed three axes, thereby meeting the requirements of multi-axis loading tests.

[0060] 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 in the scope of protection of the present invention.

Claims

1. Linear acceleration loading vehicle, characterized in that: The invention relates to a chain comprising one or more links of a chain that circulates along a circular track under the drive of a linear motor, and comprises a frame, and rail wheels, a loading assembly, a loading wheel, and an electromechanical conversion assembly connected to the frame; a drive plate and at least two groups of rail wheels are respectively provided on both sides of the frame, the drive plate is electromagnetically coupled to the output end of the linear motor, and each group of rail wheels rolls in the circular track; a floating frame for connecting to the loading wheel is provided in the middle of the frame, and the floating frame is connected to the output end of the loading assembly; The loading assembly is provided with an electric adjustment member, which is used to adjust the output load of the loading assembly; the electromechanical conversion assembly is transmission-connected to at least one group of the rail wheels and is electrically connected to the electric adjustment member.

2. The linear acceleration loading vehicle according to claim 1, characterized in that: The loading assembly includes a telescopic oil cylinder and an oil storage tank; one end of the telescopic oil cylinder is connected to the vehicle frame, and the other end is connected to the floating frame; the oil storage tank is provided with a piston and an oil chamber whose volume changes according to the movement of the piston; the oil chamber is connected to the telescopic oil cylinder via an oil circuit, and a pressure sensor is provided on the oil circuit; The pressure sensor is used to feed back an oil pressure signal to the system controller. The electric adjustment member is connected to the oil storage tank and to the piston, and the electric adjustment member is controlled by the system controller.

3. The linear acceleration loading vehicle according to claim 2, characterized in that: The floating frame is provided with an inductive baffle, the vehicle frame is provided with a displacement sensor, the sensing end of the displacement sensor is aligned with the inductive baffle, and the displacement sensor is used to detect the floating amount of the inductive baffle and feed back the detection value to the system controller.

4. The linear acceleration loading vehicle according to claim 2, characterized in that: The electric adjustment member includes a drive motor, a screw sleeve and a transmission rod; the screw sleeve is rotatably connected to the oil storage tank and is located on the side of the piston away from the oil chamber; the transmission rod passes through the screw sleeve and is connected to the piston, and the transmission rod is threadedly engaged with the screw sleeve; The driving motor is connected to the oil storage tank and the output end is transmission-connected to the screw sleeve. The driving motor is electrically connected to the electromechanical conversion assembly.

5. The linear acceleration loading vehicle according to claim 2, characterized in that: The oil storage tank is connected to a buffer air bag extending into the oil cavity, and the buffer air bag has an inflation valve extending out of the oil storage tank.

6. The linear acceleration loading vehicle according to claim 2, characterized in that: The floating frame includes two cantilever beams, one end of the cantilever beams is hinged to the frame, and the other end is hinged to the telescopic cylinder. The middle parts of the two cantilever beams are commonly connected to the loading shaft, and the loading wheel is rotatably connected to the loading shaft and is located between the two cantilever beams; wherein, two buffer blocks are provided on the frame, and the two buffer blocks are respectively supported on the ends of the two cantilever beams connected to the telescopic cylinder.

7. The linear acceleration loading vehicle according to claim 1, wherein: The electromechanical conversion assembly includes a driving pulley, a passive pulley, a first transmission belt and a generator; the generator is connected to the frame and the power input end is connected to the passive pulley, the driving pulley is coaxially connected to one group of the rail wheels and is connected to the passive pulley through the first transmission belt; the generator is electrically connected to the electric adjustment member.

8. The linear acceleration loading vehicle according to claim 7, characterized in that: Each set of rail wheels includes a first wheel body and a second wheel body that are coaxially connected and rotate in opposite directions; the first wheel body is used to roll the inner rail of the annular track, and the second wheel body is used to roll the outer rail of the annular track; wherein, the driving pulley is coaxially connected to the first wheel body; the electromechanical conversion assembly also includes a reverse transmission assembly, and the second wheel body is connected to the driven pulley through the reverse transmission assembly.

9. The linear acceleration loading vehicle according to claim 8, characterized in that: The reverse transmission assembly includes a driving gear and a reverse gear; the driving gear is coaxially connected to the second wheel body, and the reverse gear is rotatably connected to the frame and meshed with the driving gear; wherein the wheel side of the reverse gear is coaxially connected to the first transmission wheel, and the wheel side of the driven pulley is coaxially connected to the second transmission wheel, and the first transmission wheel and the second transmission wheel are connected by a second transmission belt.

10. The linear acceleration loading vehicle according to any one of claims 1 to 9, characterized in that: Two connecting shafts are spaced apart on both sides of the frame, one of the connecting shafts is hinged with a rigid link, and the other connecting shaft is hinged with a flexible link, and the rigid link and the flexible link are respectively hinged to one of the links of the chain; the connection length of the rigid link, the connection length of the flexible link, and the spacing between the two connecting shafts are all consistent with the pitch of the chain.

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