A road simulation test device and bench simulation method for a rear suspension system

Abstract

The present application relates to the field of automobile suspension testing, and in particular to a road simulation test device and bench simulation method for a rear suspension system. The test device includes: a fixing device for fixing to the ground; a frame replacement device, including a crossbeam, and a left longitudinal beam and a right longitudinal beam spaced apart; a suspension system, including two leaf springs and two leaf spring supports, the two leaf springs are fixed to the left longitudinal beam and the right longitudinal beam respectively through the leaf spring supports in a direction parallel to the left longitudinal beam, and sensors are connected to the two ends of the two leaf springs respectively; a mid-bridge replacement device and a rear-bridge replacement device, respectively slidably mounted on the two ends of the two leaf springs; four loading cylinders, respectively rotatably connected to the two ends of the mid-bridge replacement device and the rear-bridge replacement device. The road simulation test device for a rear suspension system provided by the present application can solve the problem in the related art that the stress conditions of the leaf springs of the existing rear suspension test system do not conform to reality, resulting in a large difference between the test results and the actual vehicle failure.

Description

Technical Field

[0001] The present application relates to the field of automobile suspension testing, and in particular to a road simulation test device and a bench simulation method for a rear suspension system. Background Art

[0002] At present, the leaf spring suspension system is the most widely used suspension system in commercial vehicles. It undertakes multiple functions such as load-bearing, guiding and shock absorption, and is crucial to the technical performance and safety performance of the entire vehicle. The existing leaf spring test device is generally set up as follows: first, the two ends of the leaf spring are mounted on the leaf spring support through the actual wheel track. For the front leaf spring, it is connected to the leaf spring support through the pin inserted into the lug. The support is connected to the guide rail and fixed to the iron floor. Then, the spring is clamped with U-bolts. The tightening torque of the U-bolts is strictly in accordance with the requirements specified in the drawings. Finally, an auxiliary fixture is used to connect it to the loading actuator through bolts, and the actuator applies a vertical load.

[0003] In the related technology, existing bench tests of the rear suspension assembly are all carried out independently on individual components, such as leaf spring tests and rear suspension bracket tests. However, the movements of the various components of the rear suspension under the actual vehicle are mutually influential and interrelated, and the force form is very complex, which cannot be simulated by a single bench. Therefore, the existing bench test results are very different from the actual vehicle failure.

[0004] Existing leaf springs are only loaded vertically, so test bench failures typically occur in the middle of the leaf spring, at the locating holes. However, on actual vehicles, cracks often occur at the lugs or ends, poorly matching the test bench. Analysis reveals that in the complete vehicle, the left and right leaf springs are in relative motion. Therefore, in addition to vertical loads, the leaf springs are also subject to lateral loads and S-shaped deformations. This forces the springs to bear stress at the ends, a load condition that existing test benches cannot replicate. Summary of the Invention

[0005] The embodiments of the present application provide a road simulation test device and a bench simulation method for a rear suspension system to solve the problem in the related art that the existing rear suspension test system cannot perform a complete bench test, the stress conditions of the vehicle leaf springs do not conform to reality, and the test results are greatly different from the actual vehicle failure.

[0006] In a first aspect, a rear suspension system road simulation test device is provided, comprising:

[0007] Fixing device for fixing to the ground;

[0008] A frame replacement device, comprising a crossbeam, and a left longitudinal beam and a right longitudinal beam spaced apart and parallel to the direction of vehicle travel, wherein the crossbeam is vertically connected between the left longitudinal beam and the right longitudinal beam, and the frame replacement device is fixedly connected to the fixing device and is restrained in the fixing device;

[0009] The suspension system includes two leaf springs and two leaf spring supports connected to the leaf springs, wherein the two leaf springs are fixed to the left and right longitudinal beams respectively through the leaf spring supports in a direction parallel to the left longitudinal beam; and sensors are connected to both ends of the two leaf springs;

[0010] The middle bridge replacement device and the rear bridge replacement device are respectively slidably mounted on both ends of the two leaf springs in a direction perpendicular to the left longitudinal beam;

[0011] There are four loading cylinders, which are rotatably connected to the two ends of the middle axle replacement device and the rear axle replacement device respectively.

[0012] In some embodiments, the loading cylinder includes a first loading cylinder, a second loading cylinder, a third loading cylinder, and a fourth loading cylinder;

[0013] The middle axle replacement device has middle axle mounting brackets installed at both ends and on the side away from the ground, and the rear axle replacement device has rear axle mounting brackets installed at both ends and on the side away from the ground;

[0014] The first loading cylinder and the second loading cylinder are respectively installed at both ends of the middle axle replacement device through the middle axle mounting frame, and the third loading cylinder and the fourth loading cylinder are respectively installed at both ends of the rear axle replacement device through the rear axle mounting frame.

[0015] In some embodiments, a middle bridge limit plate is provided at one end of the middle bridge replacement device close to the ground. There are two middle bridge limit plates, which are respectively located at both ends of the middle bridge replacement device. The opposing sides of the two middle bridge limit plates are respectively clamped on the sides of the two leaf springs that are away from each other.

[0016] A rear axle limit plate is provided at one end of the rear axle replacement device close to the ground. There are two rear axle limit plates, which are respectively located at both ends of the rear axle replacement device. The opposite sides of the two rear axle limit plates are respectively clamped on the sides of the two leaf springs that are away from each other.

[0017] In some embodiments, the suspension system further includes a connecting plate connecting the two leaf spring supports.

[0018] In some embodiments, the fixing device includes a plurality of fixing blocks and a transverse restraint device, wherein the transverse restraint device includes a first restraint device fixedly connected between two laterally opposite fixing blocks.

[0019] In some embodiments, there are four fixing blocks, which are fixed at the four corners of the ground to form a rectangle, and the left longitudinal beam and the right longitudinal beam are respectively fixed on two adjacent fixing blocks parallel to the forward direction of the vehicle;

[0020] There are two first restraining devices, which are respectively connected to two adjacent fixing blocks in a direction perpendicular to the left longitudinal beam and the right longitudinal beam.

[0021] In some embodiments, the lateral restraint device further includes a second restraint device connected between the left longitudinal beam and the right longitudinal beam.

[0022] In some embodiments, there are multiple second restraint devices, which are spaced apart and arranged between the left longitudinal beam and the right longitudinal beam.

[0023] In some embodiments, the loading cylinder is connected to the mid-bridge replacement device via a ball joint.

[0024] In a second aspect, a bench simulation method is provided, comprising:

[0025] Before the experiment, a road spectrum test is conducted. On a real vehicle, sensors are placed at both ends of the leaf spring. The road spectrum of relative displacement, force, and acceleration relative to the vehicle frame is obtained from the sensors placed at both ends of the leaf spring. The signals at the measurement points are used as responses, and the loading cylinder is used as excitation to calculate the transfer function. The sensors are then placed at the same locations as in any of the above-mentioned rear suspension system road simulation test devices.

[0026] The loading cylinder obtains excitation according to the transfer function and applies pressure to the suspension system.

[0027] The beneficial effects of the technical solution provided by this application include:

[0028] The embodiments of the present application provide a road simulation test device and a bench simulation method for a rear suspension system. Due to the provision of a frame substitute device, a mid-axle substitute device, and a rear-axle substitute device, a sufficient simulation environment is provided for testing the suspension system. Specifically, the suspension system is provided on the left and right longitudinal beams of the frame substitute device, the mid-axle substitute device and the rear-axle substitute device are provided at the front and rear ends of the leaf spring, respectively. Right loading cylinders are installed at both ends of the mid-axle substitute device and the rear-axle substitute device, respectively. The loading cylinders can apply force to both ends of the mid-axle substitute device and the rear-axle substitute device, and transmit this force to both ends of the leaf spring, applying vertical downward pressure to the leaf spring.

[0029] Since the center axle replacement device and the rear axle replacement device are slidably mounted on the two leaf springs and form a "well" shape with the two leaf springs, and since the four loading cylinders are rotatably connected to the center and rear axle replacement devices, corresponding to the four corners of the suspension system, the loading cylinders can apply forces in different directions to the center and rear axle replacement devices and transmit the forces to the corresponding leaf springs, causing the leaf springs on the left and right sides to have different operating phases, thereby generating lateral force, S-shaped deformation and other stress states of the leaf springs;

[0030] Before use, a full-vehicle road simulation is performed. Using the actual vehicle as the test object, the entire road simulation test process, from road spectrum acquisition to drive signal acquisition, is completed. Specifically, the displacement, force, and acceleration road spectra of the actual vehicle are collected. Using these signals at the measurement points as responses and the cylinder as excitation, the transfer function of the device is calculated. The signals from the actual vehicle are then used to inversely determine the excitation for the loading cylinder, ultimately achieving full-vehicle road simulation.

[0031] Sensors located at both ends of the leaf spring obtain data on the force, displacement, and acceleration of the leaf spring to simulate actual vehicle signals for system verification. This solves the problem in related technologies that existing rear suspension test systems are unable to conduct complete bench tests, resulting in the vehicle leaf spring force conditions not being consistent with reality, leading to significant differences between test results and actual vehicle failures. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0033] Figure 1 A schematic diagram of the three-dimensional structure of a road simulation test device for a rear suspension system provided in an embodiment of the present application;

[0034] Figure 2 A front view of a road simulation test device for a rear suspension system provided in an embodiment of the present application;

[0035] Figure 3 A top view of the rear suspension system road simulation test device provided in an embodiment of the present application.

[0036] In the figure: 1. Fixing device; 11. Fixing block; 12. Lateral restraint device; 121. First restraint device; 122. Second restraint device; 2. Frame replacement device; 21. Left longitudinal beam; 22. Right longitudinal beam; 23. Cross beam; 3. Suspension system; 31. Leaf spring; 32. Leaf spring support; 33. Connecting plate; 4. Center bridge replacement device; 41. Center bridge mounting frame; 42. Center bridge limit plate; 5. Rear axle replacement device; 51. Rear axle mounting frame; 52. Rear axle limit plate; 6. Loading cylinder; 61. First loading cylinder; 62. Second loading cylinder; 63. Third loading cylinder; 64. Fourth loading cylinder; 7. Ball joint. DETAILED DESCRIPTION

[0037] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0038] Existing bench tests for rear suspension assemblies are all conducted independently on individual components, such as leaf spring tests and rear suspension bracket tests. However, the movements of the various components of the rear suspension under the actual vehicle are mutually influential and interrelated, and the force forms are very complex, which cannot be simulated on a single bench. Therefore, the existing bench test results are very different from the actual vehicle failures.

[0039] For example, existing leaf springs are only loaded vertically, so bench failures typically occur in the middle of the leaf spring, at the locating holes. However, on actual vehicles, leaf springs often crack at the lugs or ends, which poorly corresponds to bench test results. Analysis revealed that this is due to the relative motion of the left and right leaf springs in the complete vehicle. Therefore, in addition to being able to withstand vertical loads, vehicle leaf springs in bench tests must also be able to withstand lateral loads and S-shaped deformations. This allows the leaf spring to be stressed at the ends, a stress condition that existing benches cannot achieve.

[0040] An embodiment of the present application provides a road simulation test device for a rear suspension system, which can solve the problem in the related art that the existing rear suspension test system cannot perform a complete bench test, the stress conditions of the vehicle leaf springs are not consistent with reality, and the test results are greatly different from the actual vehicle failure.

[0041] See also Figures 1 to 3 As shown, the present application provides a rear suspension system road simulation test device (hereinafter referred to as the test device), comprising:

[0042] A fixing device 1, which is used to fix to the ground;

[0043] The frame substitute device 2 includes a left longitudinal beam 21 and a right longitudinal beam 22 spaced apart and parallel to the vehicle's direction of travel, and a crossbeam 23 connected to the left and right longitudinal beams 21 and 22 to simulate the actual frame of a real vehicle. Specifically, the crossbeam 23 is welded to the left and right longitudinal beams 21 and 22. The frame substitute device 2 is fixedly connected to the fixture 1 and is restrained in the fixture 1. The frame substitute device 2 serves as a replacement frame in the test device.

[0044] The suspension system 3 includes two leaf springs 31, each of which is connected to a leaf spring support 32. Figure 1As shown, two leaf springs 31 are fixed to the left and right longitudinal beams 21 and 22 respectively through leaf spring supports 32 in a direction parallel to the left longitudinal beam 21 , and sensors are fixedly connected to both ends of the two leaf springs 31 , that is, there are four sensors, which obtain data on the force, displacement, and acceleration of the leaf springs 31 to simulate real vehicle signals;

[0045] The middle bridge replacement device 4 and the rear bridge replacement device 5 are respectively slidably mounted on both ends of the two leaf springs 31 in a direction perpendicular to the leaf spring 31, and are combined with Figure 1 and Figure 3 As shown, the middle bridge replacement device 4, the rear bridge replacement device 5 and the two leaf springs 31 form a "well" shape. Specifically, the middle bridge replacement device 4 and the rear bridge replacement device 5 are both located above the leaf springs 31 to apply force to the leaf springs 31;

[0046] The loading cylinders 6 , specifically, there are four loading cylinders 6 , which are rotatably connected to both ends of the middle axle replacement device 4 and the rear axle replacement device 5 .

[0047] When the test device is in use, the entire suspension system 3 is fixed to the vehicle frame substitute device 2 through the leaf spring support 32, and the middle bridge substitute device 4 is set at the front end of the leaf spring 31 according to the actual vehicle situation. Figure 1 The rear axle replacement device 5 is also provided at the rear end of the leaf spring 31 according to the actual vehicle situation, see Figure 1 The position shown is to provide a real vehicle simulation environment for the suspension system 3;

[0048] The four loading cylinders 6 apply downward force to both ends of the center axle replacement device 4 and the rear axle replacement device 5. The leaf springs 31 located below the center axle replacement device 4 and the rear axle replacement device 5 are also subjected to a vertical downward force. At the same time, the loading cylinders 6 correspond to the four corners of the suspension system 3. Therefore, the loading cylinders 6 can apply forces in different directions to the center axle replacement device 4 and the rear axle replacement device 5 and transmit the forces to the corresponding leaf springs 31, causing the leaf springs 31 on the left and right sides to have different operating phases.

[0049] like Figure 1 As shown, the loading cylinder 6 includes a first loading cylinder 61, a second loading cylinder 62, a third loading cylinder 63 and a fourth loading cylinder 64, wherein the first loading cylinder 61 and the second loading cylinder 62 are located on the middle axle replacement device 4, and the third loading cylinder 63 and the fourth loading cylinder 64 are located on the rear axle replacement device 5; the forces acting on the leaf spring 31 are as follows:

[0050] Case 1, vertical load: the first loading cylinder 61, the second loading cylinder 62, the third loading cylinder 63 and the fourth loading cylinder 64 simultaneously apply the same force downward, that is, the leaf springs 31 on the left and right sides are simultaneously subjected to downward force;

[0051] Case 2, side load: the first loading cylinder 61 and the third loading cylinder 63 are loaded synchronously and in the same direction, and the second loading cylinder 62 and the fourth loading cylinder 64 are loaded synchronously and in the same direction, and the loading direction of the first loading cylinder 61 and the third loading cylinder 63 is opposite to the loading direction of the second loading cylinder 62 and the fourth loading cylinder 64;

[0052] Case three, S deformation and torsion: the first loading cylinder 61 and the fourth loading cylinder 64 are loaded synchronously in the same direction, the second loading cylinder 62 and the third loading cylinder 63 are loaded synchronously in the same direction, and the loading directions of the first loading cylinder 61 and the fourth loading cylinder 64 are opposite to those of the second loading cylinder 62 and the third loading cylinder 63.

[0053] In addition, sensors are installed at both ends of the two leaf springs 31 for obtaining data on the force, displacement and acceleration of the leaf springs 31 to simulate actual vehicle signals and achieve the purpose of system verification.

[0054] Here, the situation in which the leaf spring 31 is subjected to a lateral load in the above-mentioned second situation is described:

[0055] If the four loading cylinders 6 all apply the same force to the middle bridge replacement device 4 and the rear bridge replacement device 5 at the same time as in Case 1, that is, the left and right wheel hopping movements are consistent (in a real vehicle), then the leaf spring 31 is only subjected to vertical force. However, when the loading directions of the first loading cylinder 61, the third loading cylinder 63 and the second loading cylinder 62, the fourth loading cylinder 64 are opposite, that is, the left and right are inconsistent (in a real vehicle), a phase difference is generated; since the bridge is not deformed or the deformation is small, the resulting displacement must be borne by the leaf spring 31, and the force converted into is lateral force.

[0056] The rear suspension system road simulation test device provided in the present application first performs a full vehicle road simulation before use. Using the actual vehicle as the test object, the entire road simulation test process, from road spectrum acquisition to drive signal acquisition, is completed. Specifically, the displacement, force, and acceleration road spectra of the actual vehicle are acquired. These measured signals are used as responses, and the loading cylinder 6 is used as an excitation. The transfer function of the device is calculated. The signals of the actual vehicle are then inversely excited using these transfer functions to obtain the excitation of the loading cylinder 6, ultimately achieving full vehicle road simulation.

[0057] Then, the sensors are arranged at the same position of the test device, and the four loading cylinders 6 are used as controls and the four displacement load spectra are used as responses. The road spectrum iteration is performed so that the movement of the suspension system 3 on the test bench is similar to that of the whole vehicle, thereby achieving the purpose of system verification.

[0058] It should be noted that the above-mentioned same position means that the sensor arrangement position of the test device is consistent with the sensor position measured on the actual vehicle, that is, the sensor of the test device is arranged at the same position as the sensor of the whole vehicle.

[0059] In some optional embodiments, see Figure 1 As shown, center axle replacement device 4 is equipped with center axle mounting brackets 41 at both ends of the device, which are away from the ground. First and second loading cylinders 61 and 62 are mounted to both ends of the device via center axle mounting brackets 41. Correspondingly, rear axle replacement device 5 is equipped with rear axle mounting brackets 51 at both ends of the device, which are away from the ground. Third and fourth loading cylinders 63 and 64 are mounted to both ends of the device via rear axle mounting brackets 51. Preferably, both center axle replacement device 4 and rear axle replacement device 5 use steel supports to better fit the actual vehicle and achieve better test results.

[0060] Some of the optional embodiments are shown in Figure 1 and Figure 3 As shown, the installation distance between the first loading cylinder 61 and the second loading cylinder 62 is greater than the installation distance between the left and right leaf springs 31. On the one hand, this can make the force mode of the leaf spring 31 close to the actual vehicle situation. On the other hand, it also facilitates the loading of the loading cylinder 6. It should be noted that the specific loading force is automatically calculated through the transfer function during road simulation and does not affect the loading.

[0061] In some optional embodiments, see Figure 2 As shown, a middle bridge limiting plate 42 is provided at one end of the middle bridge replacement device 4 close to the ground, and there are two middle bridge limiting plates 42, which are respectively located at both ends of the middle bridge replacement device 4. The opposite sides of the two middle bridge limiting plates 42 are respectively clamped on the sides away from the two leaf springs 31, which can prevent the middle bridge replacement device 4 from sliding left and right.

[0062] Correspondingly, two rear axle limit plates 52 are also provided at one end of the rear axle replacement device 5 close to the ground. The two rear axle limit plates 52 are respectively located at both ends of the rear axle replacement device 5 and are clamped on the sides of the two leaf springs 31 that are away from each other.

[0063] In some optional embodiments, see Figure 3 As shown, suspension system 3 includes a connecting plate 33, which connects the left and right leaf spring supports 32 and balances some of the stresses within suspension system 3. Of course, the suspension system includes more than just left and right leaf springs 31 and connecting plate 33; it also includes U-bolts, left and right suspension brackets, and various fasteners to achieve more realistic testing.

[0064] In some optional embodiments, see Figure 1 As shown, the fixing device includes multiple fixing blocks 11 and a lateral restraint device 12, wherein the lateral restraint device 12 includes a first restraint device 121, and the first restraint device 121 is fixedly connected between two laterally opposite fixing blocks 11, and the fixing blocks 11 are fixed on the ground.

[0065] Specifically, combined Figure 1 and Figure 3 As shown, there are four fixing blocks 11, which can be rectangular or as shown in FIG. Figure 1 The triangle shown in FIG, the fixing blocks 11 are fixed to the four corners of the ground to form a rectangle, and the left longitudinal beam 21 and the right longitudinal beam 22 in the frame replacement device 2 are respectively fixed on two adjacent fixing blocks 11 parallel to the direction of vehicle travel; preferably, combined with Figure 1 As shown, the left longitudinal beam 21 and the right longitudinal beam 22 are embedded in the fixed block 11;

[0066] Preferably, combined Figure 1 and Figure 3 As shown, there are two first restraining devices 121, which are respectively connected to two adjacent fixed blocks 11 in a direction perpendicular to the left longitudinal beam 21 and the right longitudinal beam 22 to restrain the tendency of the fixed blocks 11 to expand outward when loaded by the loading cylinder 6.

[0067] Optionally, the first restraint device 121 is made of steel plate. In order to reduce the influence of the fixing device 1 on the suspension system test, Figure 1 and Figure 3 As shown, holes are drilled evenly spaced apart on the first restraint device 121 to reduce its own weight and thus reduce the impact on the test.

[0068] In some optional embodiments, see Figure 3 As shown, the lateral restraint device 12 further includes a second restraint device 122. There are multiple second restraint devices 122, which are spaced apart and arranged between the left longitudinal beam 21 and the right longitudinal beam 22. Figure 3 As shown, Figure 3 Two second restraining devices 122 are provided, and the two second restraining devices 122 are respectively located on both sides of the crossbeam 23 .

[0069] Optionally, the second restraint device 122 is made of a steel plate. In order to reduce the influence of the fixing device 1 on the suspension system test, Figure 3 As shown, holes are drilled evenly spaced apart on the second restraint device 122 to reduce its own weight and thus reduce the impact on the test.

[0070] In some optional embodiments, see Figure 1 As shown, the loading cylinder 6 is connected to the middle axle replacement device 4 and the rear axle replacement device 5 respectively through a ball joint 7. Specifically, the ball joint 7 can transmit force and torque to meet the changes in the force and torque applied by this test device to the suspension system 3.

[0071] In some optional embodiments, see Figure 1 and Figure 2As shown, the loading cylinder 6 includes a hydraulic cylinder and a piston rod. Specifically, the loading cylinder realizes loading by sliding the piston rod up and down in the hydraulic cylinder, and applies force to the middle axle replacement device 4 or the rear axle replacement device 5, thereby applying force to the leaf spring 31.

[0072] In some embodiments, the top of the loading cylinder 6 is connected to a gantry crane and a control system, and the top of the loading cylinder 6 is connected to the gantry crane through a ball joint. Specifically, the control system controls the four loading cylinders 6, thereby simulating the whole vehicle to load the four leaf spring stress points, and the operating posture of the entire rear suspension system is reproduced through the whole vehicle road simulation. In this way, the suspension system can not only withstand vertical loads, but also generate lateral forces, S deformations and other stress states of the leaf springs through the difference in the operating phases of the left and right suspensions.

[0073] Before the test, sensors were placed at both ends of the two leaf springs 31 on the entire vehicle to obtain displacement relative to the frame and perform a road spectrum test. Then, sensors were arranged at the same positions on the test device. The four loading cylinders 6 were used as controls and the four displacement load spectra were used as responses. Road spectrum iteration was performed to ensure that the movement of the suspension system 3 on the test bench was similar to that of the entire vehicle, thereby achieving the purpose of system verification.

[0074] The present application provides a rear suspension system road simulation test device, which improves the bench test accuracy by simulating the road of the whole vehicle and realizing various stress conditions for the leaf spring 31 through four loading cylinders 6, and ensures that the movement of the suspension system 3 in the bench test is consistent with that of the actual vehicle, and the test results are equivalent to those of the whole vehicle test; and, after the entire suspension system 3 is assembled, it is directly installed on the frame replacement device 2, and then a mid-bridge replacement device 4 and a rear axle replacement device 5 are set on the suspension system 3, and the mid-bridge replacement device 4 and the rear axle replacement device 5 are connected with loading cylinders 6, which can improve the test efficiency, and the frame replacement device 2, the mid-bridge replacement device 4 and the rear axle replacement device 5 can be reused, and different sizes of frame replacement devices 2, the mid-bridge replacement device 4 and the rear axle replacement device 5 can be replaced according to the test needs, which can reduce the test cost. While ensuring the accuracy of the bench test, it can also replace the whole vehicle test, which can save the development cycle and reduce the test cost.

[0075] The present application also provides a bench simulation method, which comprises the following steps:

[0076] Before the experiment, a road spectrum test was conducted. Sensors were placed at both ends of the leaf spring 31 of the actual vehicle. The sensors collected the displacement, force, and acceleration road spectra of the actual vehicle. These signals at the measuring points were used as responses, and the loading cylinder 6 was used as excitation to calculate the transfer function of the device.

[0077] In the aforementioned rear suspension system road simulation test device, sensors are placed at the same position of the suspension system 3. Then, the signals measured by the actual vehicle are inversely excited using the calculated transfer function to obtain the excitation of the loading cylinder 6, ultimately achieving full vehicle road simulation.

[0078] The loading cylinder 6 applies pressure to the suspension system 3, that is, to the two leaf springs 31. Since there are four loading cylinders 6 and they are controlled separately, they can apply forces in different directions to the two ends of the two leaf springs 31, that is, the four corners of the suspension system 3, to meet different road simulation tests during vehicle operation.

[0079] In the description of this application, it should be noted that the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships 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. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0080] It should be noted that, in this application, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0081] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

Claims

1. A road simulation test device for a rear suspension system, characterized in that: It includes: A fixing device (1) for fixing to the ground; A vehicle frame replacement device (2) comprises a crossbeam (23), and a left longitudinal beam (21) and a right longitudinal beam (22) spaced apart and parallel to the vehicle running direction, wherein the crossbeam (23) is vertically connected between the left longitudinal beam (21) and the right longitudinal beam (22), and the vehicle frame replacement device (2) is fixedly connected to the fixing device (1) and is limited in the fixing device (1); A suspension system (3) includes two leaf springs (31) and two leaf spring supports (32) connected to the leaf springs (31), wherein the two leaf springs (31) are fixed to the left longitudinal beam (21) and the right longitudinal beam (22) respectively through the leaf spring supports (32) in a direction parallel to the left longitudinal beam (21); and sensors are connected to both ends of the two leaf springs (31); The middle bridge replacement device (4) and the rear bridge replacement device (5) are respectively slidably mounted on both ends of the two leaf springs (31) in a direction perpendicular to the left longitudinal beam (21); Loading cylinders (6), there are four loading cylinders (6), which are rotatably connected to the two ends of the middle axle replacement device (4) and the rear axle replacement device (5); The loading cylinder (6) comprises a first loading cylinder (61), a second loading cylinder (62), a third loading cylinder (63) and a fourth loading cylinder (64); The middle axle replacement device (4) has middle axle mounting brackets (41) installed at both ends and on the side away from the ground, and the rear axle replacement device (5) has rear axle mounting brackets (51) installed at both ends and on the side away from the ground. The first loading cylinder (61) and the second loading cylinder (62) are respectively mounted on the two ends of the middle axle replacement device (4) via the middle axle mounting frame (41), and the third loading cylinder (63) and the fourth loading cylinder (64) are respectively mounted on the two ends of the rear axle replacement device (5) via the rear axle mounting frame (51).

2. The rear suspension system road simulation test device according to claim 1, characterized in that: A middle bridge limiting plate (42) is provided at one end of the middle bridge replacement device (4) close to the ground. There are two middle bridge limiting plates (42), which are respectively located at the two ends of the middle bridge replacement device (4). The opposite sides of the two middle bridge limiting plates (42) are respectively clamped on the sides of the two leaf springs (31) that are away from each other. A rear axle limiting plate (52) is provided at one end of the rear axle replacement device (5) close to the ground. There are two rear axle limiting plates (52), which are respectively located at both ends of the rear axle replacement device (5). The opposite sides of the two rear axle limiting plates (52) are respectively clamped on the sides of the two leaf springs (31) that are away from each other.

3. The rear suspension system road simulation test device according to claim 1, characterized in that: The suspension system (3) further comprises a connecting plate (33), wherein the connecting plate (33) connects the two leaf spring supports (32).

4. The rear suspension system road simulation test device according to claim 1, characterized in that: The fixing device (1) comprises a plurality of fixing blocks (11) and a transverse restraining device (12). The transverse restraining device (12) comprises a first restraining device (121). The first restraining device (121) is fixedly connected between two laterally opposite fixing blocks (11).

5. The rear suspension system road simulation test device according to claim 4, characterized in that: There are four fixing blocks (11), which are fixed at the four corners of the ground to form a rectangle. The left longitudinal beam (21) and the right longitudinal beam (22) are respectively fixed on two adjacent fixing blocks (11) parallel to the forward direction of the vehicle. There are two first restraining devices (121), which are respectively connected to two adjacent fixing blocks (11) in a direction perpendicular to the left longitudinal beam (21) and the right longitudinal beam (22).

6. The rear suspension system road simulation test device according to claim 4, characterized in that: The lateral restraint device (12) further includes a second restraint device (122), wherein the second restraint device (122) is connected between the left longitudinal beam (21) and the right longitudinal beam (22).

7. The rear suspension system road simulation test device according to claim 6, characterized in that: There are a plurality of second restraint devices (122), which are arranged at intervals between the left longitudinal beam (21) and the right longitudinal beam (22).

8. The rear suspension system road simulation test device according to claim 1, characterized in that: The loading oil cylinder (6) is connected to the mid-bridge replacement device (4) via a ball joint (7).

9. A bench simulation method, characterized in that: The bench simulation method is applied to a rear suspension system road simulation test device, and the bench simulation method includes: Before the experiment, a road spectrum test is performed. On a real vehicle, sensors are arranged at both ends of the leaf spring (31). The road spectrum of relative displacement, force and acceleration with the frame is obtained through the sensors arranged at both ends of the leaf spring (31) of the whole vehicle. The signal of the measuring point is used as a response, and the loading cylinder (6) is used as an excitation to calculate the transfer function. The sensors are arranged at the same position as the rear suspension system road simulation test device as described in any one of claims 1 to 8. The loading cylinder (6) obtains excitation according to the transfer function and applies pressure to the suspension system (3).

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