Automobile steel plate spring fatigue test equipment and test method

Abstract

The invention discloses automobile steel plate spring fatigue test equipment and a test method, a push-pull test device of the automobile steel plate spring fatigue test equipment comprises a mounting assembly and a push-pull assembly, and the mounting assembly comprises a test platform, a first fixing part and a second fixing part; the push-pull assembly comprises a hydraulic servo actuator and a connecting part, the hydraulic servo actuator is connected with the side, close to the second fixing part, of the first fixing part, a mounting distance is formed between the hydraulic servo actuator and the test platform, and the hydraulic servo actuator can drive a telescopic rod of the telescopic cylinder to stretch out and draw back in a reciprocating mode in the first direction; a control computer of the simulation test control device is electrically connected with a hydraulic control system, the hydraulic control system is communicated with a hydraulic servo actuator, and the control computer is used for controlling the hydraulic pressure applied to the hydraulic servo actuator by the hydraulic control system according to first path spectrum information obtained in advance. The system can simulate the real automobile use condition, greatly improves the test accuracy, and is high in practicality and popularization.

Description

Technical Field

[0001] The invention relates to automobile leaf spring fatigue testing equipment and a testing method, belonging to the technical field of reliability testing of key automobile parts. Background Art

[0002] As one of the key components, automotive leaf springs are currently widely used in pickup trucks, trucks, and special vehicles. They mainly play a load-bearing and shock-absorbing role for the body load. As an important part of the automobile suspension system, the material of the leaf spring has an important impact on the performance and service life of the car. In the application of automobile springs, leaf springs are generally made of 65Mn (65 manganese steel). This material is widely used to withstand harsh conditions such as impact, pressing, and wear due to its excellent performance and strength. The hardness of 65Mn is below HRC20. After heat treatment, the hardness can reach above HRC60, and the hardness after quenching is generally around HRC62. The hardness range of automobile spring steel plates is between HRC40-55. Different hardnesses are required according to the requirements of different models, such as passenger cars, SUVs, off-road vehicles, military vehicles, trucks, etc., so they need to be customized according to the requirements of the model. The road simulation test of automobile leaf springs is of great significance to the development of product reliability and the promotion of industry verification technology progress.

[0003] However, the existing leaf spring fatigue test device can only measure the service life of the leaf spring according to the enterprise standard, and cannot simulate the actual automobile use conditions, which makes the accuracy of the leaf spring fatigue test results low. Summary of the invention

[0004] In view of this, an object of the present invention is to provide an automobile leaf spring fatigue test device and a test method, so as to at least solve the problem mentioned in the background technology that the existing leaf spring fatigue test device cannot simulate the actual automobile use condition.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] An automobile leaf spring fatigue testing device, comprising:

[0007] A push-pull test device, the push-pull test device comprises a mounting assembly and a push-pull assembly, the mounting assembly comprises a test platform, a first fixing component and a second fixing component, the first fixing component and the second fixing component are installed on the test platform at intervals along a first direction, and the second fixing component is at least used to install a leaf spring to be tested; the push-pull assembly comprises a hydraulic servo actuator and a connecting component, the hydraulic servo actuator is connected to a side of the first fixing component close to the second fixing component and has an installation distance with the test platform, the hydraulic servo actuator comprises a telescopic cylinder, the hydraulic servo actuator can drive the telescopic rod of the telescopic cylinder to reciprocate and extend along the first direction, and the connecting component is installed on a side of the telescopic rod close to the second fixing component to be detachably connected to at least the leaf spring to be tested;

[0008] A simulation test control device, the simulation test control device includes a control computer and a hydraulic control system, the control computer is electrically connected to the hydraulic control system, the hydraulic control system is connected to the hydraulic servo actuator, the control computer is used to control the hydraulic pressure applied to the hydraulic servo actuator by the hydraulic control system according to the first road spectrum information acquired in advance, so that the hydraulic servo actuator drives the telescopic rod to reciprocate and extend along the first direction under the action of the hydraulic pressure, and the first road spectrum information is the first displacement of the leaf spring along its own telescopic direction at different times during the vehicle's driving on a predetermined road surface.

[0009] Furthermore, the hydraulic control system comprises:

[0010] an oil source, the oil source being electrically connected to the control computer;

[0011] A hydraulic distributor, wherein the hydraulic distributor and the oil source are connected via a hydraulic pipeline, the hydraulic distributor is connected to the hydraulic servo actuator via a hydraulic oil pipe, and the hydraulic distributor is electrically connected to the control computer.

[0012] Furthermore, the first fixing component includes:

[0013] An installation box is set up on the test platform, and the hydraulic servo actuator is fixedly connected to a side wall of the installation box on a side close to the second fixing component;

[0014] A crimping assembly is used to crimp the installation box onto the test platform.

[0015] Furthermore, the mounting box includes a first side panel, a second side panel, a third side panel and a bottom panel, the bottom panel is crimped onto the test platform through the crimping assembly, the first side panel is located on a side of the bottom panel close to the second fixing component, the first side panel is fixedly connected to the hydraulic servo actuator, the second side panel is located on a side of the bottom panel away from the second fixing component, and the third side panel is located between the first side panel and the second side panel.

[0016] Further, a plurality of mounting grooves are arranged on the surface of the test platform, the plurality of mounting grooves are arranged at intervals along the second direction, the length of the mounting grooves extends along the first direction, an avoidance hole is arranged through the bottom plate, and the crimping assembly includes:

[0017] Side pressure plates, the side pressure plates include at least two, the at least two side pressure plates are respectively located on opposite sides of the bottom plate along the second direction, wherein the side pressure plates are provided with avoidance grooves near the bottom of the test platform, the groove bottoms of the avoidance grooves of at least two side pressure plates are in contact with the upper surface of the bottom plate, and the parts of at least two side pressure plates offset from the avoidance grooves are laid on the test platform;

[0018] An intermediate pressing plate, the intermediate pressing plate is placed on the bottom plate and covers at least a portion of the avoidance hole;

[0019] The first bolt set includes a first bolt body and a first T-shaped protrusion, the first T-shaped protrusion is adapted to the mounting groove and clamped in the mounting groove, the first bolt body includes a plurality of first bolt bodies, and the plurality of first bolt bodies are respectively penetrated through the side pressure plate and the middle pressure plate and extend into the mounting groove and are fixedly connected to the first T-shaped protrusion.

[0020] Furthermore, the first fixing component further includes:

[0021] The longitudinal stop blocks include at least three blocks, at least three of which are spaced apart along the second direction and abut against a side of the mounting box away from the hydraulic servo actuator, and at least three of the longitudinal stop blocks are fixedly connected to the test platform via a bolt set.

[0022] Furthermore, the second fixing component includes: a mounting beam, a fixing structure and a support rod, the support rod includes at least two, and the at least two support rods are arranged on the test platform at intervals along the second direction, the mounting beam is fixed to the top of the at least two support rods away from the test platform, and the fixing structure includes at least two, and the at least two fixing structures are arranged on the mounting beam at intervals along the second direction.

[0023] Furthermore, a plurality of transverse grooves with the same or different spacings are provided on one side of the mounting box close to the hydraulic servo actuator, a connecting seat and a second bolt set are provided between the hydraulic servo actuator and the mounting box, the second bolt set includes a plurality of second bolt bodies and a plurality of second T-shaped protrusions, the structure of the transverse grooves is adapted to the second T-shaped protrusions, the plurality of second T-shaped protrusions are respectively clamped in at least two of the transverse grooves, and a plurality of second bolt bodies are penetrated through the opposite sides of the connecting seat and are fixedly connected to the plurality of second T-shaped protrusions one by one.

[0024] Furthermore, the simulation test control device further comprises a sensor, the sensor being mounted on the telescopic rod and being electrically connected to the control computer, the sensor being used to detect a second displacement amount generated by the leaf spring to be tested when the telescopic rod is reciprocated and extended along a first direction and transmit the second displacement amount to the control computer, so that the control computer controls the hydraulic control system to drive the telescopic rod to drive the leaf spring to be tested to reach the first displacement amount according to the second displacement amount, or controls the hydraulic control system to stop working;

[0025] The second displacement is equal to the first displacement, greater than the first displacement, or less than the first displacement.

[0026] Furthermore, the push-pull assembly further includes:

[0027] A force relief mechanism is installed on the test platform and connected to the hydraulic servo actuator, and is used for applying a pulling force away from the test platform to the hydraulic servo actuator.

[0028] Furthermore, the force release mechanism comprises:

[0029] A gantry, the gantry being fixed on the test platform, and along the third direction, a side of the gantry away from the test platform is higher than the height of the hydraulic servo actuator;

[0030] A spring fixing plate, wherein the spring fixing plate is fixed to a side of the gantry away from the test platform;

[0031] A shock absorbing spring, wherein the shock absorbing spring comprises a plurality of springs, and the plurality of shock absorbing springs are arranged at intervals along the second direction and connected to the spring fixing plate;

[0032] A hook connecting plate is connected to the bottom of the plurality of damping springs away from the spring fixing plate, and the hydraulic servo actuator is connected to the hook connecting plate via a connecting belt.

[0033] Furthermore, the push-pull test device is provided in multiple configurations, and the oil pressure distributor includes multiple hydraulic output ports, and the multiple hydraulic output ports are connected to the hydraulic servo actuators of the multiple push-pull test devices in a one-to-one correspondence.

[0034] Furthermore, the automobile leaf spring fatigue test method is performed using the automobile leaf spring fatigue test equipment, and the method comprises the following steps:

[0035] Step s1, collecting, by controlling a computer, first displacements of the leaf spring along its own expansion and contraction direction at different times during driving of a vehicle equipped with a leaf spring on a predetermined road surface, so as to generate first road spectrum information from the first displacements at different times;

[0036] Step s2, controlling the hydraulic pressure applied to the hydraulic servo actuator by the hydraulic control system through the control computer according to the first spectrum information, so that the hydraulic servo actuator drives the telescopic rod of the telescopic cylinder to reciprocate and retract along the first direction under the action of the hydraulic pressure, and applies the tension and pressure generated when the telescopic rod reciprocates and retracts along the first direction to the leaf spring to be tested installed on the second fixed component.

[0037] Furthermore, before executing step s2, the method further includes:

[0038] The control computer receives the second displacement generated by the leaf spring to be tested when the telescopic rod reciprocates and retracts along the first direction detected by the sensor, so that the control computer controls the hydraulic control system to drive the telescopic rod to drive the leaf spring to be tested to reach the first displacement according to the second displacement, or controls the hydraulic control system to stop working.

[0039] Further, the control computer controls the hydraulic control system to drive the telescopic rod of the hydraulic servo actuator to drive the leaf spring to be tested to reach the first displacement according to the second displacement, comprising:

[0040] The control computer obtains a control error e(t) according to the difference between the second displacement and the first displacement, wherein the control error e(t)=r(t)-y(t), wherein r(t) is the first displacement and y(t) is the second displacement;

[0041] The control computer outputs a hydraulic control signal u(t) to the oil pressure distributor of the hydraulic control system through a proportional-integral-differential controller according to the control error e(t), so that the oil pressure distributor drives the telescopic rod to drive the leaf spring to be tested to reach the first displacement in response to the hydraulic control signal u(t), wherein the hydraulic control signal u(t) satisfies the following formula:

[0042]

[0043] In the formula, K p is the proportional gain, K i is the integration time, K d is the differential time.

[0044] Furthermore, before the control computer controls the hydraulic pressure applied to the hydraulic servo actuator by the hydraulic control system according to the first spectrum information, the method further includes:

[0045] The control computer increases or decreases the first displacement at different times in the first path spectrum information by a predetermined multiple, and generates second path spectrum information, so as to control the hydraulic pressure applied to the hydraulic servo actuator by the hydraulic control system according to the second path spectrum information through the control computer.

[0046] Compared with the prior art, the beneficial effects of the present invention are:

[0047] (1) The structure of the present invention is stable and reliable, and the cost is low. The first road spectrum information of the real road surface of the automobile test field, such as ordinary roads and comprehensive reinforced roads, can be collected through the simulation test control device. The hydraulic control system can output energy to the hydraulic servo actuator through the control computer to drive the hydraulic servo actuator to move according to the first displacement at different times displayed in the first road spectrum information, and act on the leaf spring to be tested. It can simulate the leaf spring to be tested under the actual automobile use conditions, and then accurately test the fatigue durability performance of the leaf spring on the actual road. There is no need for test personnel to conduct field tests on the leaf spring to be tested, which greatly improves the fatigue resistance test efficiency of the leaf spring and reduces the test cost caused by personnel testing;

[0048] (2) The present invention can realize closed-loop control, which adjusts the output of the control computer by comparing the difference between the expected input signal and the actual output signal, thereby improving the test accuracy and precision and timeliness of the entire automobile leaf spring fatigue test equipment, and ensuring that the automobile leaf spring fatigue test equipment can maintain good dynamic characteristics and stability under various working conditions;

[0049] (3) It is easy to operate and has good reliability. Different road spectrum information can be used to test the leaf springs to be tested according to their actual material properties, ensuring that the leaf springs to be tested have good bearing capacity and avoiding damage during the test. In addition, road spectrum information can be collected on a predetermined road surface for testing. The operation is convenient and efficient, reducing the workload of test personnel, improving test efficiency and reducing test costs. It has strong practicality and high promotion potential.

[0050] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings, in which:

[0052] Figure 1 A schematic diagram of the top structure of an automobile leaf spring fatigue testing device provided by one embodiment of the present invention;

[0053] Figure 2 for Figure 1 A schematic diagram of the front structure of

[0054] Figure 3 for Figure 1 A schematic diagram of the side structure of

[0055] Figure 4 for Figure 3 A partial enlarged schematic diagram of part A;

[0056] Figure 5 for Figure 1 The three-dimensional structure of Figure 1 ;

[0057] Figure 6 for Figure 1 The three-dimensional structure of Figure 2 ;

[0058] Figure 7 for Figure 1 The three-dimensional structure of Figure 3 ;

[0059] Figure 8 for Figure 7 A partial enlarged schematic diagram of part B in the middle;

[0060] Fig. 9 for Figure 7 A partial enlarged schematic diagram of part C in the middle;

[0061] Fig.10 for Figure 1 The three-dimensional structure of Figure 4 ;

[0062] Fig.11 for Fig.10 The partial enlarged schematic diagram of part D in the middle;

[0063] Fig.12It is a schematic diagram of the installation structure of the simulation test control device;

[0064] Fig.13 It is a flowchart of the simulation test process of the present invention;

[0065] Fig.14 It is the original data diagram of the collected road spectrum;

[0066] Fig.15 This is the data graph after the road spectrum is cut and processed;

[0067] Fig.16 This is the data graph after the road spectrum is iteratively processed;

[0068] Fig.17 This is the control principle diagram of the hydraulic servo actuator by the control computer.

[0069] In the figure: 1. test platform; 101. mounting groove; 2. second fixing component; 201. mounting crossbeam; 202. fixing structure; 2021. fixing support; 2022. connecting arm; 203. support rod; 204. mounting base plate; 205. convex bolt; 3. first fixing component; 301. mounting box; 3011. first side plate; 3012. second side plate; 3013. third side plate; 3014. base plate; 3015. avoidance hole; 3016. transverse slide groove; 302. side pressure plate; 3021. avoidance groove; 303. middle pressure plate; 304. longitudinal stop block; 305. first bolt set; 3051. first bolt body; 3052. first T-shaped convex block; 4. hydraulic servo actuation Device; 401, telescopic cylinder; 4011, telescopic rod; 402, hydraulic oil pipe; 403, connecting seat; 4031, fixing block; 4032, fork-shaped connecting part; 404, second bolt set; 405, oil source; 406, oil pressure distributor; 5, simulation test control device; 501, control computer; 502, sensor; 6, leaf spring to be tested; 7, force release mechanism; 701, gantry; 702, spring fixing plate; 703, shock-absorbing spring; 704, hook connecting plate; 705, hook; 706, threaded connector; 8, connecting belt; 9, connecting component; 901, locking member; 902, first limit plate; 903, second limit plate; 904, first fixing block; 905, second fixing block. DETAILED DESCRIPTION

[0070] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0071] like Figure 1-Figure 13 As shown, the first embodiment of the present invention provides an automobile leaf spring fatigue test device, which includes a push-pull test device and a simulation test control device 5.

[0072] The push-pull test device includes an installation component and a push-pull component. The installation component includes a test platform 1, a first fixing component 3 and a second fixing component 2. The first fixing component 3 and the second fixing component 2 are installed on the test platform 1 at intervals along the first direction (Y direction). The second fixing component 2 is at least used to install the leaf spring 6 to be tested. The push-pull component includes a hydraulic servo actuator 4 and a connecting component 9. The hydraulic servo actuator 4 is connected to the side of the first fixing component 3 close to the second fixing component 2 and has an installation distance with the test platform 1. The hydraulic servo actuator 4 includes a telescopic cylinder 401. The hydraulic servo actuator 4 can drive the telescopic rod 4011 of the telescopic cylinder 401 to reciprocate and extend along the first direction. The connecting component 9 is installed on the side of the telescopic cylinder close to the second fixing component 2 to be detachably connected to at least the leaf spring 6 to be tested, so as to facilitate the installation of different leaf springs 6 to be tested on the second fixing component 2 for fatigue resistance testing. The overall structure of the push-pull test device is easy to assemble, which improves the efficiency of the preparation work in the early stage of the test.

[0073] The simulation test control device 5 includes a control computer 501 and a hydraulic control system. The control computer 501 is electrically connected to the hydraulic control system, and the hydraulic control system is connected to the hydraulic servo actuator 4. The control computer 501 is used to control the hydraulic pressure applied to the hydraulic servo actuator 4 by the hydraulic control system according to the first road spectrum information obtained in advance, so that the hydraulic servo actuator 4 drives the telescopic rod 4011 to reciprocate and retract along the first direction under the action of the hydraulic pressure. During the process of the telescopic rod 4011 reciprocating and retracting along the first direction, the steel leaf spring 6 to be tested is driven to produce telescopic deformation, so as to realize the fatigue test of the steel leaf spring 6 to be tested. The first road spectrum information is the first displacement amount of the steel leaf spring along its own telescopic direction at different times during the vehicle's driving on the predetermined road surface. That is to say, in this embodiment, it is only necessary to test a vehicle equipped with a steel leaf spring on the predetermined road surface, and test the first displacement amount of the steel leaf spring on the vehicle at different times and different positions on the predetermined road surface, so as to obtain the required first road spectrum information. During subsequent testing, it is only necessary to control the telescopic rod 4011 of the hydraulic servo actuator 4 to perform telescopic movement by the control computer 501 according to the first spectrum information to perform anti-fatigue test on the leaf spring 6 to be tested. This can improve the accuracy of the fatigue test results of the leaf spring 6 to be tested, and the operation is efficient and convenient, saving labor costs.

[0074] like Figure 8As shown, the connection component 9 in this embodiment includes a connection body, at least four locking members 901, a first limit plate 902 and a second limit plate 903. The connection body is fixedly connected to the end of the telescopic rod 4011 close to the second fixed member 2 or is integrally formed with the telescopic rod 4011, and the integrally formed setting is convenient for processing. The connection body includes a first fixed block 904 and a second fixed block 905, and the first fixed block 904 and the second fixed block 905 are respectively located on opposite sides of the telescopic rod 4011 along the direction indicated by X. The first fixed block 904 and the second fixed block 905 are respectively abutted against a side of the to-be-tested leaf spring 6 arranged on the second fixed member 2 close to the telescopic rod 4011, and the first fixed block 904 and the second fixed block 905 are both extended out of the to-be-tested leaf spring 6 on opposite sides along the Z direction. The first limit plate 902 is located at a side of the leaf spring 6 to be tested away from the telescopic rod 4011 and is arranged corresponding to the first fixed block 904. At least two locking members 901 are respectively located at two opposite sides of the first fixed block along the Z direction and penetrate the first fixed block 904 to be detachably connected to the first limit plate 902. The second limit plate 903 is located at a side of the leaf spring 6 to be tested away from the telescopic rod 4011 and is arranged corresponding to the second fixed block 905. At least two locking members 901 are respectively located at two opposite sides of the second fixed block 905 along the Z direction and penetrate the second fixed block 905 to be detachably connected to the second limit plate 903. Thus, in this embodiment, the telescopic rod 4011 is detachably connected to the leaf spring 6 to be tested through the connection seat, at least four locking members 901, the first limiting plate 902 and the second limiting plate 903, which can not only realize the fatigue test of different leaf springs 6 to be tested, but also ensure the connection strength and stability between the leaf spring 6 to be tested and the telescopic rod 4011 during the test, and the overall structure is assembled efficiently and conveniently. The locking member 901 can be specifically a bolt, a screw, etc.

[0075] The hydraulic control system includes an oil source 405 and an oil pressure distributor 406. The oil source 405 is electrically connected to the control computer 501, so that the control computer 501 can control the oil source 405 to deliver hydraulic oil to the oil pressure distributor 406. The oil pressure distributor 406 and the oil source 405 are connected through a hydraulic pipeline. Specifically, the hydraulic pipeline includes an oil return pipeline and an oil delivery pipeline. The oil delivery pipeline is provided with an oil supply pump, which is connected to the control computer 501 through a cable, and the control computer 501 automatically controls the output of hydraulic oil. The telescopic cylinder 401 of the hydraulic servo actuator 4 is connected to the oil pressure distributor 406 through the hydraulic oil pipe 402, and the oil pressure distributor 406 is electrically connected to the control computer 501. The control computer 501 collects the first road spectrum information of the real road surface of the automobile test site, and controls the oil pressure distributor 406 to output hydraulic energy to the hydraulic servo actuator 4, thereby driving the telescopic rod 4011 of the hydraulic servo actuator 4 to move according to the first displacement in the first road spectrum information and act on the leaf spring 6 to be tested, and at the same time feeds back the action signal to the control computer 501. One end of the telescopic rod 4011 of the telescopic cylinder 401 is connected to the leaf spring 6 to be tested through the connecting component 9, and the end away from the telescopic rod 4011 is connected to the first fixing component 3 through the connecting seat 403.

[0076] Therefore, this embodiment can control the oil source 405 to deliver hydraulic oil to the oil pressure distributor 406 through the control computer 501, and control the oil pressure distributor 406 to output hydraulic pressure to the hydraulic servo actuator 4, so that the hydraulic servo actuator 4 is sufficient to make the telescopic rod 4011 drive the tested leaf spring 6 to move a first displacement in the first direction under the hydraulic pressure, thereby realizing anti-fatigue testing of the tested leaf spring 6 according to the first road spectrum information collected under real road conditions, thereby improving the testing accuracy of the tested leaf spring 6.

[0077] The first fixing component 3 includes a mounting box 301 and a crimping assembly, the mounting box 301 is set on the test platform 1, the hydraulic servo actuator 4 is fixedly connected to the side wall of the mounting box 301 close to the second fixing component; the crimping assembly is used to crimp the mounting box 301 to the test platform 1. In this embodiment, the mounting box 301 is crimped to the test platform 1 by the crimping assembly, which is convenient for assembly and can ensure the stability between the mounting box 301 and the test platform 1 during the test process, thereby improving the stability and reliability of the overall equipment during the test process.

[0078] The installation box 301 includes a first side plate 3011, a second side plate 3012, a third side plate 3013 and a bottom plate 3014. The bottom plate 3014 is crimped onto the test platform 1 through a crimping assembly. The first side plate 3011 is located on a side of the bottom plate 3014 close to the second fixing component 2. The first side plate 3011 is fixedly connected to the hydraulic servo actuator 4. The second side plate 3012 is located on a side of the bottom plate 3014 away from the second fixing component. The third side plate 3013 is located between the first side plate 3011 and the second side plate 3012. The first side plate 3011, the second side plate 3012, the third side plate 3013 and the bottom plate 3014 are integrally formed to form the installation box 301, thereby ensuring the overall structural strength of the installation box 301.

[0079] The test platform 1 is a cast iron floor with a slide groove. Specifically, a plurality of mounting grooves 101 are arranged on the surface of the test platform 1, and the plurality of mounting grooves 101 are arranged at intervals along the second direction (X direction), and the length of the mounting grooves 101 extends along the first direction, and an avoidance hole 3015 is arranged through the bottom plate 3014. The crimping assembly includes a side pressure plate 302, an intermediate pressure plate 303 and a first bolt set 305, the side pressure plate 302 includes at least two and at least two side pressure plates 302 are respectively located on opposite sides of the bottom plate along the second direction, wherein the side pressure plate 302 is provided with an avoidance groove 3021 near the bottom of the test platform 1, the groove bottoms of the avoidance grooves 3021 of at least two side pressure plates 302 are both in contact with the upper surface of the bottom plate 3014, and at least two side pressure plates 302 are staggered in the avoidance grooves 3021 and are laid on the test platform 1; the intermediate pressure plate 303 is laid on the bottom plate 3014 and covers at least part of the avoidance hole 3015 of the bottom plate; Figure 3-Figure 4 As shown, the first bolt set 305 includes a first bolt body 3051 and a first T-shaped protrusion 3052. The first T-shaped protrusion 3052 is adapted to the mounting groove 101 of the test platform 1 and is clamped in the mounting groove 101. The first bolt body 3052 includes a plurality of first bolt bodies 3051, which are respectively penetrated and arranged on the side pressure plate 302 and the middle pressure plate 303 and extend into the mounting groove 101 of the test platform 1 and are fixedly connected to the first T-shaped protrusion 3052. In this embodiment, the mounting box 301 is stably and firmly mounted on the test platform 1 through the side pressure plate 302, the middle pressure plate 303 and the first bolt set 305, and the connection strength and stability between the mounting box 301 and the test platform 1 are improved through the fit between the first T-shaped protrusion 3052 and the mounting groove 101.

[0080] The first fixing component also includes a longitudinal abutment block 304, which includes at least three pieces. The at least three longitudinal abutment blocks 304 are arranged at intervals along the second direction and abut against the side of the installation box 301 away from the hydraulic servo actuator 4, and at least three of the longitudinal abutment blocks 304 are fixedly connected to the test platform 1 through a bolt set. At least three longitudinal abutment blocks 304 can apply an abutment force toward the hydraulic servo actuator 4 to the installation box 301, thereby buffering the thrust acting on the installation box 301 during the movement of the telescopic rod 4011 of the hydraulic servo actuator 4, further improving the stability of the installation box 301 relative to the test platform 1, and preventing the installation box 301 from slipping due to the thrust applied by the telescopic rod 4011 of the hydraulic servo actuator 4, thereby further improving the test accuracy of the push-pull test device on the leaf spring 6 to be tested.

[0081] The side of the installation box 301 close to the hydraulic servo actuator 4 is provided with a plurality of transverse grooves 3016 with the same or different spacings, the connecting seat 403 is fixed on the transverse grooves 3016 by the second bolt set 404, and the end of the telescopic cylinder 401 away from the telescopic rod 4011 is connected to the connecting seat 403. Figure 8 As shown, the connection seat 403 includes a fixed block 4031, and the fixed block 4031 is provided with a fork-shaped connecting portion 4032 matching the connecting ear of the telescopic cylinder 401 at one end close to the telescopic cylinder 401, and abuts against the mounting box 301 at the side away from the telescopic cylinder 401. The structure of the second bolt set 404 is similar to that of the first bolt set 305, and specifically includes a plurality of second bolt bodies and a plurality of second T-shaped protrusions. The structure of the transverse slide 3016 is adapted to the second T-shaped protrusions, and the plurality of second T-shaped protrusions are respectively clamped in at least two of the transverse slides 3016. The plurality of second bolt bodies penetrate the opposite sides of the fixed block 4031 of the connection seat 403 and are fixedly connected to the plurality of second T-shaped protrusions one by one. Among them, the hydraulic servo actuator 4 is installed and fixed on the transverse slide 3016 of the mounting box 301. The installation height and left and right position of the hydraulic servo actuator 4 can be adjusted through the transverse slide 3016, which is suitable for testing leaf springs of different models and has a wider range of applications. The mounting box 301 is made of gray cast iron, which has good stability and impact toughness, and the mounting box 301 is firmly fixed on the test platform 1 through the pressure plate assembly, which can effectively resist the large recoil force generated during the movement of the hydraulic servo actuator 4.

[0082] The second fixing component 2 includes a mounting beam 201, a fixing structure 202 and a support rod 203. The support rod 203 includes at least two, at least two support rods 203 are spaced apart along the second direction on the test platform 1. The mounting beam 201 is fixed to the top of the at least two support rods 203 away from the test platform 1. The fixing structure 202 includes at least two, at least two fixing structures 202 are spaced apart along the second direction on the mounting beam 201. The opposite ends of the leaf spring 6 to be tested along the second direction (i.e., the opposite sides of the length direction of the leaf spring 6 to be tested) are respectively fixed to the mounting beam 201 through corresponding fixing structures 202. For the convenience of installation, the mounting beam 201 is made of large channel steel parts, and fixing structures 202 matching the leaf spring 6 to be tested are set at the two ends of the top of the mounting beam 201. The fixing structure 202 can be selected and installed according to the structure of the leaf spring 6 to be tested, such as a fixed axle seat, a clamping structure, etc. Specifically, Figure 8 As shown, the fixing structure 202 includes a fixing support 2021, the lower end of which is connected to the mounting crossbeam 201 by bolts, and the fixing support 2021 is close to the telescopic rod 4011. The connecting arm 2022 includes two connecting arms, which are arranged at intervals along the height direction of the fixing support 2021. The end of the leaf spring 6 to be tested is clamped in the clamping space formed between the two connecting arms 2022. The connecting arm 2022 is provided with a mounting hole group, so that the end of the leaf spring 6 to be tested is connected and restricted in the clamping space by the connecting bolts arranged in the mounting hole group. Support rods 203 are symmetrically arranged at both ends of the bottom of the mounting crossbeam 201, so that the mounting crossbeam 201 is fixed to the test platform 1 through the support rods 203. Specifically, a mounting base plate 204 is provided at the bottom of the support rod 203 , and a plurality of mounting holes are provided on the mounting base plate 204 . The mounting base plate 204 is fixedly connected to the slide groove of the test platform 1 via convex bolts 205 provided in the mounting holes.

[0083] In this embodiment, the simulation test control device 5 also includes a sensor 502, which is installed on the telescopic rod 4011 of the telescopic cylinder 401 and is electrically connected to the control computer 501. The sensor 502 is used to detect the second displacement of the leaf spring 6 to be tested when the telescopic rod 4011 reciprocates and retracts along the first direction, and transmits the second displacement to the control computer 501, so that the control computer 501 can control the hydraulic control system according to the second displacement, and then drive the telescopic rod 4011 of the hydraulic servo actuator 4 to drive the leaf spring 6 to be tested to reach the first displacement. Wherein, the second displacement is equal to the first displacement or greater than the first displacement or less than the first displacement. The second displacement generated by the leaf spring 6 to be tested is monitored in real time by the sensor 502, and dynamic feedback adjustment is realized, so that the control of the fatigue resistance test according to the first spectrum information can be made more accurate. Alternatively, the hydraulic control system can be controlled to stop working urgently by the sensor 502 to avoid misoperation of the equipment and improve the reliability of the overall device.

[0084] In this embodiment, the push-pull test device can be multiple settings, and the oil pressure distributor 406 includes multiple hydraulic output ports, and the multiple hydraulic output ports are connected to the hydraulic servo actuators 4 of multiple push-pull test devices one by one. The hydraulic servo actuators 4 of multiple push-pull test devices can be controlled simultaneously by one oil pressure distributor 406, so that fatigue tests can be performed on multiple leaf springs 6 to be tested at the same time, thereby improving the test efficiency.

[0085] like Figure 1-Figure 13 As shown, on the basis of the first embodiment, the second embodiment of the present invention provides an automobile leaf spring fatigue test equipment, wherein the push-pull assembly further includes a force release mechanism 7, which is installed on the test platform 1 and connected to the hydraulic servo actuator 4, and the force release mechanism 7 is used to apply a pulling force away from the test platform 1 to the hydraulic servo actuator 4. Since the hydraulic servo actuator 4 has a large cylinder weight, if the force release mechanism is not provided, a large friction force will be generated between the telescopic rod 4011 and the cylinder body of the telescopic cylinder 401 under the action of gravity, thereby wearing out the telescopic cylinder 401. After the force release mechanism is provided, during the simulation test, the friction force between the telescopic rod 4011 and the cylinder body is reduced, thereby improving the service life of the hydraulic servo actuator 4.

[0086] The hydraulic servo actuator 4 is connected to the test platform 1 through a force relief mechanism. The force relief mechanism is arranged between the first fixing component 3 and the second fixing component 2, and is connected to the middle of the hydraulic servo actuator 4. The force relief mechanism can realize force relief and support to the middle of the hydraulic servo actuator 4, ensure the stability of the hydraulic servo actuator 4, ensure the normal operation of the telescopic rod 4011 of the hydraulic servo actuator 4, and not be affected by the side stress, and at the same time make the hydraulic servo actuator 4 have a certain shock absorption effect during the movement process, thereby improving the test accuracy.

[0087] The de-energizing mechanism comprises a gantry 701, a spring fixing plate 702, a shock absorbing spring 703 and a hook connecting plate 704. The gantry 701 is fixed on the test platform 1. Along the third direction (Z direction), the side of the gantry 701 away from the test platform 1 is higher than the height of the hydraulic servo actuator 4. The spring fixing plate 702 is fixed to the side of the gantry 701 away from the test platform 1. The shock absorbing spring 703 comprises a plurality of springs, and the plurality of shock absorbing springs 703 are arranged at intervals along the second direction and connected to the spring fixing plate 702. The hook connecting plate 704 is connected to one end of the plurality of shock absorbing springs 703 away from the spring fixing plate 702. The hydraulic servo actuator 4 is connected to the hook connecting plate 704 via a connecting belt 8. In this embodiment, only one shock absorbing spring 703 may be provided. However, providing a plurality of shock absorbing springs 703 will make the pulling force applied by the de-energizing mechanism to the hydraulic servo actuator 4 stronger and more evenly distributed.

[0088] A hook 705 is provided at the lower part of the hook connecting plate 704; the hydraulic servo actuator 4 is connected to the hook 705 through a connecting belt 8. A threaded connector 706 is provided on the side of the telescopic cylinder 401 of the hydraulic servo actuator 4 close to the hook connecting plate 704. The lower part of the threaded connector 706 has an external thread, which is threadedly connected and tightened with a threaded hole pre-set on the hydraulic servo actuator 4. A connecting hole is provided on the side of the threaded connector 706 close to the hook connecting plate 704. The connecting belt 8 passes through the connecting hole to connect the hook 705 and the threaded connector together, and then the hydraulic servo actuator 4 is connected to the hook connecting plate 704 together, which is convenient to connect. The threaded connector 706 is easy to process. When installing, it is only necessary to set a threaded hole on the telescopic cylinder 401 of the hydraulic servo actuator 4 that is compatible with the external thread set at the lower part of the threaded hole threaded connector 706, and the assembly is efficient and convenient.

[0089] Specifically, the gantry 701 is composed of a gantry beam and supporting columns symmetrically arranged at both ends of the bottom of the gantry beam, and the bottom ends of the supporting columns are connected to the slide slots of the test platform 1 through support plates. The spring fixing plate 702 is fixed to the gantry beam by welding or bolting. The spring fixing plate 702 and the hook connecting plate 704 are respectively provided with a plurality of U-shaped hooks corresponding to the shock absorbing springs 703 on one side close to each other, and the upper end of the shock absorbing spring 703 close to the spring fixing plate 702 is suspended on the spring fixing plate 702 through the U-shaped hook, and the lower end of the shock absorbing spring 703 close to the hook connecting plate 704 is connected to the hook connecting plate 704.

[0090] Among them, at least eight shock-absorbing springs 703 are provided.

[0091] The connecting belt 8 can be a connecting piece with adjustable length such as a screw rod, a telescopic rod 4011 structure, etc., which is convenient for disassembly, assembly and replacement.

[0092] like Figure 13-Figure 17 As shown, a fatigue test method for an automobile leaf spring is performed using the above-mentioned automobile leaf spring fatigue test equipment, and the method comprises the following steps:

[0093] Step s1, collecting, by controlling the computer 501, first displacements of the leaf spring along its own expansion and contraction direction at different times during the driving of the vehicle equipped with the leaf spring on a predetermined road surface, so as to generate first road spectrum information from the first displacements at different times;

[0094] Step s2, controlling the hydraulic control system to apply hydraulic pressure to the hydraulic servo actuator 4 according to the first spectrum information by controlling the computer 501, so that the hydraulic servo actuator 4 drives the telescopic rod 4011 of the telescopic cylinder 401 to reciprocate and retract along the first direction under the action of hydraulic pressure, and applies the tension and pressure generated when the telescopic rod 401 reciprocates and retracts along the first direction to the leaf spring 6 to be tested installed on the second fixed component 2.

[0095] The automobile leaf spring fatigue test method provided by the embodiment of the present invention can collect the first road spectrum information of the real road surface of the automobile test field such as ordinary road and comprehensive reinforced road surface by controlling the computer 501, and control the hydraulic control system by controlling the computer 501 to output energy to the hydraulic servo actuator 4 to drive the telescopic rod 4011 of the hydraulic servo actuator 4 to move according to the first displacement at different times displayed in the first road spectrum information, and make the movement of the telescopic rod 4011 act on the leaf spring 6 to be tested, which can simulate the leaf spring 6 to be tested under the actual automobile use conditions, and then can accurately test the fatigue durability performance of the leaf spring 6 to be tested on the actual road. There is no need for test personnel to conduct field tests on the leaf spring 6 to be tested, which greatly improves the anti-fatigue test efficiency of the leaf spring 6 to be tested and reduces the test cost caused by personnel testing.

[0096] Before executing the step s2, the method further includes: the control computer 501 receives the second displacement amount generated by the steel leaf spring 6 to be tested when the telescopic rod 4011 reciprocates and retracts along the first direction detected by the sensor 502, so that the control computer 501 controls the hydraulic control system to drive the telescopic rod 4011 to drive the steel leaf spring 6 to be tested to reach the first displacement amount according to the second displacement amount, or controls the hydraulic control system to stop working. Among them, the second displacement amount generated by the steel leaf spring 6 to be tested is detected in real time by the sensor 502, and dynamic adjustment is achieved, so that the steel leaf spring 6 to be tested can accurately reach the first displacement amount, thereby improving the control accuracy. When the operation is improper, a protection value can be preset in the control computer 501. When the second displacement amount measured by the sensor 502 is much larger than the first displacement amount and exceeds the protection value, an emergency stop is achieved.

[0097] Specifically, the step of the control computer 501 controlling the hydraulic control system to drive the telescopic rod 4011 of the hydraulic servo actuator 4 to drive the leaf spring 6 to reach the first displacement according to the second displacement includes:

[0098] The control computer 501 obtains a control error e(t) according to the difference between the second displacement and the first displacement, and the control error e(t)=r(t)-y(t), wherein r(t) is the first displacement and y(t) is the second displacement; e(t) can be obtained by outputting a difference signal after comparing the first displacement and the second displacement by a numerical comparator set in the control computer 501, or can be obtained by comparing through a pre-set comparison program instruction.

[0099] The control computer 501 outputs a hydraulic control signal u(t) to the oil pressure distributor 406 of the hydraulic control system through a proportional-integral-differential controller according to the control error e(t), so that the oil pressure distributor 406 responds to the hydraulic control signal u(t) and drives the telescopic rod 4011 to drive the leaf spring 6 to be tested to reach the first displacement, wherein the hydraulic control signal u(t) satisfies the following formula:

[0100]

[0101] In the formula, K p is the proportional gain, K i is the integration time, K d is the differential time, K p e(t) is the proportional part, K p e(t) is directly proportional to the control error e(t) and responds quickly to error changes; is the integral part, Accumulating all past errors helps eliminate steady-state errors. is the differential part, Predict future trends and reduce overshoot and oscillation. The time variable t represents the time from the start of the control process (i.e., the first time the telescopic rod 4011 is controlled to move) to the current moment, and t is used to represent the value of the error e(t) at the current moment and the rate of change of the error over time. The time variable τ represents a series of time points in the integration process. In , τ is the integral variable, which is used to represent the error value at all time points from the start time 0 to the current time t. The integral term calculates the cumulative effect of the total error by accumulating the error values ​​at these time points, thereby eliminating the steady-state error.

[0102] Specific example:

[0103] Assume that at a certain time t = 5 seconds, the control error e(t) is 2, then:

[0104] Proportional term K p e(5) reflects the error value at t=5 seconds.

[0105] Integral Item It reflects the accumulation of all error values ​​from 0 seconds to 5 seconds.

[0106] Differential term It reflects the rate of change of the error at t = 5 seconds.

[0107] Therefore, in the hydraulic control system of this embodiment, in order to ensure the stability and accuracy of the system, this embodiment uses a closed-loop control strategy. The core of this closed-loop control strategy is to adjust the output of the control computer 501 by comparing the difference between the expected input signal (i.e., the first displacement set in the first spectrum information) and the actual output signal (the second displacement obtained by sensor feedback), thereby achieving precise control of the hydraulic control system. The oil pressure distributor 406 of the hydraulic control system adjusts the pressure parameters of the hydraulic oil provided to the hydraulic servo actuator 4 in response to the hydraulic control signal u(t). Specifically, the control computer 501 can convert the calculated hydraulic control signal u(t) into a physical quantity, such as voltage or current, which is used to adjust the position or opening of the hydraulic valve of the oil pressure distributor 406, thereby changing the pressure of the hydraulic cylinder of the oil pressure distributor 406 or the position of the piston, so that the hydraulic servo actuator 4 can accurately control the leaf spring 6 to be tested to reach the first displacement. After the system responds, the sensor obtains new actual values ​​again and repeats the above process to form a continuous feedback loop, thereby improving the test accuracy and timeliness of the entire automotive leaf spring fatigue test equipment, and ensuring that the automotive leaf spring fatigue test equipment can maintain good dynamic characteristics and stability under various working conditions.

[0108] Before the hydraulic pressure applied to the hydraulic servo actuator 4 by the control computer 501 according to the first spectrum information is controlled by the hydraulic control system, the method further includes:

[0109] After the first displacement at different moments in the first road spectrum information is increased or decreased by a predetermined multiple by the control computer 501, the second road spectrum information is generated, so that the hydraulic pressure applied to the hydraulic servo actuator 4 by the hydraulic control system is controlled by the control computer 501 according to the second road spectrum information. Therefore, different road spectrum information can be used to test the leaf springs 6 to be tested according to their actual material properties, so as to avoid damage to the leaf springs 6 to be tested due to the first displacement exceeding the bearing capacity, or inaccurate testing of the leaf springs 6 to be tested due to insufficient first displacement. In addition, anti-fatigue testing through the second road spectrum information can also avoid the test personnel from re-collecting road spectrum information with a larger or smaller amplitude on the predetermined road surface, thereby reducing the workload of the test personnel, improving the test efficiency and reducing the test cost. The predetermined multiple may be one of 1.2 times, 1.3 times, 1.5 times, 2 times, 2.3 times, 2.5 times, 2.6 times, 2.8 times, 3 times, 3.1 times, 3.4 times, 3.5 times, 3.7 times, 3.8 times, etc. The predetermined multiple may also be other multiple values ​​besides the aforementioned data. This embodiment does not make a sole limitation on this.

[0110] The first spectrum information is a set of time series data, and each time point corresponds to a first displacement. Specifically, in this embodiment, when the first displacement at different times in the first spectrum information is increased or decreased by a predetermined multiple by the control computer 501, the control computer 501 can use a predetermined programming language (the predetermined programming language can include Python) to read the first spectrum information and adjust the displacement according to the predetermined multiple. At this time, the control computer 501 can specifically perform the following method steps:

[0111] 1. The first route map information can be set to be stored in a CSV file. When reading the route map data, a programming language (such as Python) can be used to read the route map data. Here Python is used as an example:

[0112] Python

[0113] import pandas as pd

[0114] #Read CSV file

[0115] file_path='path_to_your_spectrum_file.csv'

[0116] data = pd.read_csv(file_path)

[0117] #Assume that there is a column named 'time' in the data file to represent time, and a column named 'displacement' to represent the first displacement

[0118] time = data['time']

[0119] displacement=data['displacement']

[0120] ```

[0121] 2. Apply multiple adjustment:

[0122] Adjust the size of the first displacement according to a predetermined multiple. Assume that you want to increase or decrease the first displacement by `scale_factor` times:

[0123] Python

[0124] scale_factor = 1.5 # For example, increase by 1.5 times

[0125] # Apply multiple adjustment

[0126] adjusted_displacement=displacement*scale_factor

[0127] ```

[0128] 3. Save the adjusted data:

[0129] Save the adjusted data into a new file to obtain the second spectrum information for subsequent testing.

[0130] Python

[0131] #Create a new DataFrame

[0132] adjusted_data=pd.DataFrame({

[0133] 'time':time,

[0134] 'adjusted_displacement':adjusted_displacement

[0135] })

[0136] #Save to a new CSV file

[0137] output_file_path='path_to_your_adjusted_spectrum_file.csv'

[0138] adjusted_data.to_csv(output_file_path,index=False)

[0139] ```

[0140] 4. Verification results:

[0141] You can verify through visualization or other means whether the adjusted data is as expected.

[0142] Python

[0143] import matplotlib.pyplot as plt

[0144] #Draw the original first displacement and the adjusted displacement

[0145] plt.figure(figsize=(10,6))

[0146] plt.plot(time,displacement,label='Original Displacement')

[0147] plt.plot(time,adjusted_displacement,label='Adjusted Displacement',linestyle="--')

[0148] plt.xlabel('Time(s)')

[0149] plt.ylabel('Displacement')

[0150] plt.legend()

[0151] plt.title('Displacement Adjustment')

[0152] plt.show()

[0153] Full code example:

[0154] Python

[0155] import pandas as pd

[0156] import matplotlib.pyplot as plt

[0157] #Read CSV file

[0158] file_path='path_to_your_spectrum_file.csv'

[0159] data = pd.read_csv(file_path)

[0160] #Assume that there is a column named 'time' in the data file to represent time, and a column named 'displacement' to represent displacement

[0161] time = data['time']

[0162] displacement=data['displacement']

[0163] # Apply multiple adjustment

[0164] scale_factor = 1.5 # For example, increase by 1.5 times

[0165] adjusted_displacement=displacement*scale_factor

[0166] #Create a new DataFrame

[0167] adjusted_data=pd.DataFrame({

[0168] 'time':time,

[0169] 'adjusted_displacement':adjusted_displacement

[0170] })

[0171] #Save to a new CSV file

[0172] output_file_path='path_to_your_adjusted_spectrum_file.csv'.

[0173] In step s1, the first road spectrum information of the real predetermined road surface of the automobile test site such as ordinary road and comprehensive reinforced road surface is collected; the first road spectrum information is the first displacement of the leaf spring at different times during the vehicle driving process, and the first road spectrum information is formed after data processing using the American MTS eDAQ data processing system. Generally, the simulation test is carried out using an equivalent road surface of a predetermined length such as 500,000 kilometers or 1 million kilometers, and simulation tests of different kilometers can also be carried out according to the standard requirements of automobile R&D enterprises; and the obtained first road spectrum information is imported into the control computer 501.

[0174] The equipment required for the first road spectrum information collection includes data acquisition device, data processing software, data acquisition software, displacement sensor, triaxial sensor, strain gauge. The specific steps for collecting road spectrum data are as follows:

[0175] s1.1. Place the displacement sensor, X, Y, Z three-axis sensor, and strain gauge on the leaf spring of the test vehicle, connect them to the data acquisition system, and then drive the vehicle to the test track, and drive over the washboard road, Belgian road, cobblestone road, twisted road, pothole road, vibrating road, wavy road, noisy road, ordinary road, high-speed ring road, mountain road and other roads at a constant speed. The vibration and amplitude are transmitted to the data acquisition device through the sensor, and the time history curve of the vibration and strain gauge signal is collected by the data acquisition device, such as Fig.14 shown.

[0176] s1.2. After the first spectrum information is collected, the collected first spectrum information is cut and iteratively processed in the data processing software cRPC Project Manager. Cut off the part with greater damage contribution, and keep as much as possible the part with no damage contribution or less damage contribution, so that the frequency components and amplitudes of the strain signals before and after do not change significantly, indicating that the trimmed signal can effectively reflect the load environment during driving, thereby improving the accuracy of the test results obtained after the fatigue test of the leaf spring to be tested using the first spectrum information, such as Fig.15 shown.

[0177] s1.3. After the cutting is completed, the first road spectrum information is iteratively processed, and the cut road spectrum data is used as the iterative target of the road simulation system test bench, and the acceleration signal is reproduced in the time domain through the test bench closed-loop control strategy. Fig.16 As shown, the blue is the target signal and the red is the response signal. The target signal and the response signal overlap with each other, indicating that the test bench can accurately reproduce the vibration environment conditions of the prototype vehicle during actual driving.

[0178] In step s2, the hydraulic control system is controlled by the simulation test control device 5 to output energy to the hydraulic servo actuator 4, driving the hydraulic servo actuator 4 to start moving according to the first displacement at different times in the first road spectrum information, and acting on the leaf spring 6 to be tested, thereby evaluating the fatigue durability performance of the leaf spring on the actual road.

[0179] In addition, the second displacement generated when the telescopic rod 4011 of the telescopic cylinder 401 of the hydraulic servo actuator 4 reciprocates and retracts along the first direction is detected in real time by the sensor 502 and the second displacement is transmitted to the control computer 501, so that the control computer 501 adjusts the hydraulic pressure applied to the hydraulic servo actuator 4 by the hydraulic control system according to the second displacement. The second displacement matches the first displacement of the spring to be compressed determined in the first path spectrum information. When the detection feedback to the control computer 501 is that the displacement of the telescopic rod 4011 is insufficient, the control computer 501 controls the oil pressure distributor 406 to give more hydraulic strength, realizes feedback adjustment, and makes the test results more accurate. Specifically, when the displacement generated when the telescopic rod 4011 reciprocates and retracts along the first direction is smaller than that specified in the path spectrum, the hydraulic pressure applied to the hydraulic servo actuator 4 by the hydraulic control system is increased. On the contrary, when the second displacement is larger than the first displacement specified in the first path spectrum information, the control computer 501 controls the hydraulic control system to reduce the hydraulic pressure applied to the hydraulic servo actuator 4.

[0180] The specific steps of the simulation test are:

[0181] s2.1. Place the leaf spring 6 to be tested on the test platform 1 and install it on the second fixing component 2. After the installation is completed, turn on the high voltage power supply of the equipment system;

[0182] s2.2, the control computer 501 applies high pressure to the oil source, and the hydraulic servo actuator 4 moves by relying on the high pressure oil source;

[0183] s2.3, control the hydraulic servo actuator 4 to communicate with the computer, specifically open the computer software statusmanager → apply low pressure to the hydraulic servo actuator 4 → apply high pressure to the hydraulic servo actuator 4 → open the cRPC ProjectManager software → import the cut and iterated road spectrum → click to run. After clicking to run, the hydraulic servo actuator 4 will vibrate the steel leaf spring according to the collected road spectrum. If the hydraulic servo actuator 4 is placed vertically, the hydraulic servo actuator 4 will move up and down. If the hydraulic servo actuator 4 is placed horizontally, the hydraulic servo actuator 4 will move left and right or back and forth. That is, the movement direction of the hydraulic servo actuator 4 simulates the movement of the steel leaf spring in the corresponding direction during driving.

[0184] As can be seen from the above, the automobile leaf spring fatigue test equipment provided by the embodiment of the present invention has a stable and reliable structure and low cost. It can directly collect the first road spectrum information of the real road surface of the automobile test field such as ordinary roads and comprehensive reinforced roads through the simulation test control device or the control computer 501, and can control the hydraulic control system through the control computer 501 to output energy to the hydraulic servo actuator 4 to drive the hydraulic servo actuator 4 to move according to the first displacement at different times displayed in the first road spectrum information, and act on the leaf spring 6 to be tested. It can simulate the leaf spring 6 to be tested under the actual automobile use conditions, and then accurately test the fatigue durability performance of the leaf spring 6 to be tested on the actual road. There is no need for test personnel to conduct field tests on the leaf spring 6 to be tested, which greatly improves the fatigue resistance test efficiency of the leaf spring 6 to be tested and reduces the test cost caused by personnel testing;

[0185] Secondly, the embodiment of the present invention can realize closed-loop control, which adjusts the output of the control computer 501 by comparing the difference between the expected input signal and the actual output signal, thereby improving the test accuracy and precision and timeliness of the entire automobile leaf spring fatigue test equipment, and ensuring that the automobile leaf spring fatigue test equipment can maintain good dynamic characteristics and stability under various working conditions. The overall equipment is easy to operate and has good reliability. It can use different road spectrum information to test the leaf springs 6 to be tested according to their actual material properties, ensuring that the leaf springs 6 to be tested have good bearing capacity and avoid damage during the test. In addition, the road spectrum information can be collected on a predetermined road surface for testing. The operation is convenient and efficient, reducing the workload of test personnel, improving test efficiency and reducing test costs. It has strong practicality and high promotion potential.

[0186] The above description is only a preferred embodiment of the present invention and does not constitute any form of confidentiality restriction on the present invention. Any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. An automobile leaf spring fatigue test equipment, characterized in that: include: A push-pull test device, the push-pull test device comprising an installation component and a push-pull component, the installation component comprising a test platform (1), a first fixing component (3) and a second fixing component (2), the first fixing component (3) and the second fixing component (2) being installed on the test platform (1) at intervals along a first direction, the second fixing component (2) being used for installing at least a leaf spring (6) to be tested; the push-pull component comprising a hydraulic servo actuator (4) and a connecting component (9), the hydraulic servo actuator (4) being connected to a side of the first fixing component close to the second fixing component (2) and having an installation distance with the test platform (1), the hydraulic servo actuator (4) comprising a telescopic cylinder (401), the hydraulic servo actuator (4) being capable of driving a telescopic rod (4011) of the telescopic cylinder (401) to reciprocate and extend in the first direction, the connecting component (9) being installed on a side of the telescopic rod (4011) close to the second fixing component (2) so as to be detachably connected to at least the leaf spring (6) to be tested; A simulation test control device (5), the simulation test control device (5) comprising a control computer (501) and a hydraulic control system, the control computer (501) being electrically connected to the hydraulic control system, the hydraulic control system being connected to the hydraulic servo actuator (4), the control computer (501) being used to control the hydraulic pressure applied to the hydraulic servo actuator (4) by the hydraulic control system according to first road spectrum information acquired in advance, so that the hydraulic servo actuator (4) drives the telescopic rod (4011) to reciprocate and retract along a first direction under the action of the hydraulic pressure, the first road spectrum information being the first displacement amount of the leaf spring along its own telescopic direction at different times during the vehicle's driving on a predetermined road surface.

2. The automobile leaf spring fatigue testing equipment according to claim 1, characterized in that: The hydraulic control system comprises: An oil source (405), the oil source (405) being electrically connected to the control computer (501); The oil pressure distributor (406) is connected to the oil source (405) via a hydraulic pipeline, the oil pressure distributor (406) is connected to the hydraulic servo actuator (4) via a hydraulic oil pipe (402), and the oil pressure distributor (406) is electrically connected to the control computer (501).

3. The automobile leaf spring fatigue testing equipment according to claim 1, characterized in that: The first fixing component (3) comprises: An installation box (301), the installation box (301) is set up on the test platform (1), and the hydraulic servo actuator (4) is fixedly connected to a side wall of the installation box (301) close to the second fixing component (2); A crimping assembly, wherein the crimping assembly crimps the installation box (301) onto the test platform (1).

4. The automobile leaf spring fatigue testing equipment according to claim 3, characterized in that: The installation box (301) comprises a first side plate (3011), a second side plate (3012), a third side plate (3013) and a bottom plate (3014); the bottom plate (3014) is crimped onto the test platform (1) through the crimping assembly; the first side plate (3011) is located on a side of the bottom plate (3014) close to the second fixing component (2); the first side plate (3011) is fixedly connected to the hydraulic servo actuator (4); the second side plate (3012) is located on a side of the bottom plate (3014) away from the second fixing component; and the third side plate (3013) is located between the first side plate (3011) and the second side plate (3012).

5. The automobile leaf spring fatigue testing equipment according to claim 4, characterized in that: The test platform (1) is provided with a plurality of mounting grooves (101) on its surface, the plurality of mounting grooves (101) being arranged at intervals along the second direction, the length of the mounting grooves (101) extending along the first direction, the bottom plate (3014) being provided with an avoidance hole (3015) penetrating therein, and the crimping assembly comprising: A side pressure plate (302), the side pressure plates (302) comprising at least two pieces, the at least two side pressure plates (302) being respectively located on opposite sides of the bottom plate (3014) along the second direction, wherein the side pressure plates (302) are provided with avoidance grooves (3021) near the bottom of the test platform (1), the groove bottoms of the avoidance grooves (3021) of at least two side pressure plates (302) are both in contact with the upper surface of the bottom plate (3014), and the parts of at least two side pressure plates (302) that are offset from the avoidance grooves (3021) are laid on the test platform (1); An intermediate pressing plate (303), the intermediate pressing plate (303) being mounted on the bottom plate (3014) and covering at least a portion of the avoidance hole (3015); A first bolt set (305), the first bolt set (305) comprises a first bolt body (3051) and a first T-shaped protrusion (3052), the first T-shaped protrusion (3052) is adapted to the installation groove (101) and is clamped in the installation groove (101), the first bolt body (3051) comprises a plurality of first bolt bodies (3051), the plurality of first bolt bodies (3051) are respectively penetrated on the side pressure plate (302) and the middle pressure plate (303) and extend into the installation groove (101) to be fixedly connected with the first T-shaped protrusion (3052).

6. The automobile leaf spring fatigue testing equipment according to claim 5, characterized in that: The first fixing component (3) further comprises: A longitudinal stop block (304), the longitudinal stop block (304) comprising at least three blocks, the at least three longitudinal stop blocks (304) being arranged at intervals along the second direction and abutting against a side of the mounting box (301) away from the hydraulic servo actuator (4), and the at least three longitudinal stop blocks (304) being fixedly connected to the test platform (1) via a bolt set.

7. The automobile leaf spring fatigue testing equipment according to claim 1, characterized in that: The second fixing component (2) comprises: a mounting crossbeam (201), a fixing structure (202) and a support rod (203); the support rod (203) comprises at least two, and the at least two support rods (203) are arranged on the test platform (1) at intervals along the second direction; the mounting crossbeam (201) is fixed to the top of the at least two support rods (203) away from the test platform (1); the fixing structure (202) comprises at least two, and the at least two fixing structures (202) are arranged on the mounting crossbeam (201) at intervals along the second direction.

8. The automobile leaf spring fatigue testing equipment according to claim 3, characterized in that: A plurality of transverse grooves (3016) with the same or different spacings are provided on one side of the installation box (301) close to the hydraulic servo actuator (4); a connecting seat (403) and a second bolt set (404) are provided between the hydraulic servo actuator (4) and the installation box (301); the second bolt set (404) includes a plurality of second bolt bodies and a plurality of second T-shaped protrusions; the structure of the transverse groove (3016) is adapted to the second T-shaped protrusions; the plurality of second T-shaped protrusions are respectively clamped in at least two of the transverse grooves (3016); the plurality of second bolt bodies are arranged on opposite sides of the connecting seat (403) and are fixedly connected to the plurality of second T-shaped protrusions in a one-to-one correspondence.

9. The automobile leaf spring fatigue testing equipment according to claim 1, characterized in that: The simulation test control device (5) further comprises a sensor (502), wherein the sensor (502) is mounted on the telescopic rod (4011) and is electrically connected to the control computer (501), and the sensor (502) is used to detect a second displacement amount generated by the steel leaf spring (6) to be tested when the telescopic rod (4011) reciprocates and retracts along a first direction, and transmit the second displacement amount to the control computer (501), so that the control computer (501) controls the hydraulic control system to drive the telescopic rod (4011) to drive the steel leaf spring (6) to be tested to reach the first displacement amount according to the second displacement amount, or controls the hydraulic control system to stop working; The second displacement is equal to the first displacement, greater than the first displacement, or less than the first displacement.

10. The automobile leaf spring fatigue testing equipment according to any one of claims 1 to 9, characterized in that: The push-pull assembly also includes: A force relief mechanism (7), wherein the force relief mechanism (7) is installed on the test platform (1) and connected to the hydraulic servo actuator (4), and the force relief mechanism (7) is used to apply a pulling force away from the test platform (1) to the hydraulic servo actuator (4).

11. The automobile leaf spring fatigue testing equipment according to claim 10, characterized in that: The force release mechanism (7) comprises: A gantry (701), the gantry (701) being fixed on the test platform (1), and along the third direction, a side of the gantry (701) away from the test platform (1) is higher than the height of the hydraulic servo actuator (4); A spring fixing plate (702), wherein the spring fixing plate (702) is fixed to a side of the gantry (701) away from the test platform (1); A shock absorbing spring (703), wherein the shock absorbing spring (703) comprises a plurality of springs, and the plurality of shock absorbing springs (703) are arranged at intervals along the second direction and connected to the spring fixing plate (702); A hook connecting plate (704) is connected to the bottom of the plurality of shock absorbing springs (703) away from the spring fixing plate (702), and the hydraulic servo actuator (4) is connected to the hook connecting plate (704) via a connecting belt (8).

12. The automobile leaf spring fatigue testing equipment according to claim 2, characterized in that: The push-pull test device is provided in multiple configurations, and the oil pressure distributor (406) includes multiple hydraulic output ports, and the multiple hydraulic output ports are connected one-to-one with the hydraulic servo actuators (4) of the multiple push-pull test devices.

13. A fatigue test method for automobile leaf springs, characterized in that: The automobile leaf spring fatigue test method is performed using the automobile leaf spring fatigue test equipment according to any one of claims 1 to 12, and the method comprises the following steps: Step s1, collecting, by means of a control computer (501), first displacements of the leaf spring along its own expansion and contraction direction at different times during the driving of the vehicle equipped with the leaf spring on a predetermined road surface, so as to generate first road spectrum information from the first displacements at different times; Step s2, controlling the hydraulic pressure applied to the hydraulic servo actuator (4) by the hydraulic control system through the control computer (501) according to the first spectrum information, so that the hydraulic servo actuator (4) drives the telescopic rod (4011) of the telescopic cylinder (401) to reciprocate and extend in a first direction under the action of the hydraulic pressure, and applies the tension and pressure generated when the telescopic rod (4011) reciprocates and extends in the first direction to the leaf spring (6) to be tested mounted on the second fixed component (2).

14. The automobile leaf spring fatigue test method according to claim 13, characterized in that: Before executing step s2, the method further includes: The control computer (501) receives a second displacement amount generated by the leaf spring (6) to be tested when the telescopic rod (4011) reciprocates and retracts along a first direction, detected by the sensor (502), so that the control computer (501) controls the hydraulic control system to drive the telescopic rod (4011) to drive the leaf spring (6) to be tested to reach the first displacement amount according to the second displacement amount, or controls the hydraulic control system to stop working.

15. The automobile leaf spring fatigue test method according to claim 14, characterized in that: The step of the control computer (501) controlling the hydraulic control system to drive the telescopic rod (4011) of the hydraulic servo actuator (4) to drive the leaf spring (6) to be tested to reach the first displacement according to the second displacement comprises: The control computer (501) obtains a control error e(t) according to the difference between the second displacement and the first displacement, wherein the control error e(t)=r(t)-y(t), wherein r(t) is the first displacement and y(t) is the second displacement; The control computer (501) outputs a hydraulic control signal u(t) to the oil pressure distributor (406) of the hydraulic control system through a proportional-integral-differential controller according to the control error e(t), so that the oil pressure distributor (406) drives the telescopic rod (4011) to drive the leaf spring (6) to be tested to reach the first displacement in response to the hydraulic control signal u(t), wherein the hydraulic control signal u(t) satisfies the following formula: In the formula, K p is the proportional gain, K i is the integration time, K d is the differential time.

16. The automobile leaf spring fatigue test method according to claim 13, characterized in that: Before the control computer (501) controls the hydraulic pressure applied to the hydraulic servo actuator (4) by the hydraulic control system according to the first spectrum information, the method further comprises: The control computer (501) increases or decreases the first displacement at different times in the first path spectrum information by a predetermined multiple, thereby generating second path spectrum information, so as to control the hydraulic pressure applied to the hydraulic servo actuator (4) by the hydraulic control system according to the second path spectrum information through the control computer (501).

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