Electric truck frame fatigue performance bench test device and method

Abstract

The application discloses a kind of electric truck frame fatigue performance test rig device and method, it is related to the performance test of automobile key parts technical field, in front support setting torsion shaft, main plate and side support and with rear support combination use, realize the bending and torsional fatigue performance test of frame using same test rig, in goods box loading system with two day beam makes load uniform distribution, by adjusting six air springs in gas pressure, and by six pressure sensors reading load value, realize to different loading quality electric truck frame different goods box load, avoid the trouble caused by repeatedly increasing and decreasing weight block quantity, improve test rig loading efficiency, the torsional fatigue test dynamic load of frame, according to the maximum static load that electric truck is loaded when front axle bears, calculate the maximum static load that each wheel bears in single-side front wheel suspension, multiplied by dynamic load coefficient and front axle wheel base, obtain the maximum fatigue dynamic load of frame torsional fatigue test.

Description

Technical Field

[0001] This invention belongs to the field of performance testing technology for key automotive components, specifically relating to a bench test device and method for fatigue performance testing of electric truck chassis. Background Technology

[0002] Electric freight vehicles, due to their low energy consumption and environmental friendliness, play a vital role in short-distance urban logistics and are increasingly favored by users. However, the increased weight of the power battery system increases the dynamic load on the chassis, significantly impacting the structural strength, stiffness, and especially fatigue life of the electric freight vehicle chassis, leading to premature fatigue failure. Therefore, designing a simple bench test device and method for the fatigue performance of electric freight vehicle chassis that can quickly adjust the cargo box load value on the chassis to adapt to different load capacities is crucial for accelerating the performance testing and product development of electric freight vehicle chassis.

[0003] Currently, there are also some patents for fatigue performance testing of truck frames. For example, Chinese invention patent application number CN106468622B discloses a frame torsional fatigue test bench with a load distribution device. The front and rear suspensions of the frame assembly are fixed to simulated suspensions. A jack-driven lever mechanism applies a vertical static load to the frame, simulating cargo weight. Two actuators on the gantry move the front simulated suspension with a 180° phase difference, applying a periodic torsional load to the frame and continuously conducting torsional fatigue tests. The disadvantage of this patented technical solution is that the concentrated load applied by the lever arm and jack does not match the uniformly distributed load of actual vehicle conditions, which significantly affects the frame fatigue life test results. Chinese invention patent application number CN111780985A discloses a heavy-duty vehicle frame bending and torsional fatigue test bench device and method. It collects the torsional angles of the front and rear crossbeams during the vehicle's operation, and inputs torsional loads at both ends of the front and rear axles through four torsional cylinders. At the same time, it simulates the cargo box and cargo load state of the actual vehicle through an airbag loading unit to conduct bending and torsional fatigue tests on the frame. The patented technology has three technical defects: First, it only considers the cargo load of the cargo box and does not consider the load of the cab and powertrain; second, for the truck frame structure, the cargo box load is applied locally by three sets of airbag loading units instead of applying an overall uniform load to the cargo box; third, the test method of applying frame fatigue load by collecting the torsional angles of the front and rear crossbeams of the frame during the vehicle's service life is only applicable after the prototype vehicle has been developed, and cannot be used to simulate and predict the fatigue performance of the frame and conduct bench tests during the frame product development stage and before the prototype vehicle is developed, making it difficult to conduct forward design and development of the frame. Summary of the Invention

[0004] In view of the above-mentioned problems in the prior art, the purpose of the present invention is to provide a bench test device and method for fatigue performance of electric truck frames.

[0005] This invention provides the following technical solution:

[0006] A bench test apparatus for fatigue performance of an electric truck frame includes a frame. A front support and a rear support are mounted on the bottom of the frame. The front support is located at the front of the frame, and the rear support is located at the rear of the frame. Leaf spring beams are mounted on both the front and rear supports and are connected to the bottom of the frame. The front support includes a front bracket, which includes a torsion shaft and a main plate. The main plate is connected to the torsion shaft, and the top of the main plate is connected to the leaf spring beam. Side limiting structures are movably mounted at both ends of the main plate to constrain the main plate from rotating around the torsion shaft.

[0007] As a further technical solution, the frame includes a left longitudinal beam, a right longitudinal beam, a front crossbeam, a second crossbeam, a third crossbeam, a fourth crossbeam, a fifth crossbeam, and a rear crossbeam. The front support also includes a front base plate. A concave vertical plate is welded to the front base plate, and vertical plate reinforcing ribs are welded to the front and rear sides of the concave vertical plate. The torsion shaft is mounted on the concave vertical plate, and a bearing upper seat is also mounted on the concave vertical plate. The bearing upper seat is located above the torsion shaft. A bearing side cover is mounted on one side of the bearing upper seat and the concave vertical plate. The bearing side cover is located on one side of the torsion shaft. The main plate is connected to the torsion shaft. A connecting seat is mounted on the main plate, and a hollow support beam is mounted on the connecting seat. The hollow support beam is connected to the leaf spring beam. The connecting seat includes a lower connecting plate, which is mounted on the main plate. A lower column is welded to the lower connecting plate, and an upper connecting plate is welded to the top of the lower column. A T-shaped groove is opened at the bottom end of the hollow support beam, and the upper connecting plate is slidably connected to the T-shaped groove.

[0008] As a further technical solution, the side limiting structure includes a side bracket, the side bracket includes a side base plate, a side upright plate is welded on the side base plate, the top of the side upright plate abuts against both sides of the main board, and reinforcing ribs one are welded on the left and right sides of the side upright plate, and reinforcing ribs two are welded on the front and rear sides of the side upright plate.

[0009] As a further technical solution, the side limiting structure includes a side base plate, which is fixed to the ground iron by bolts. Slide rails are symmetrically arranged on the side base plate, and an electric slide table is slidably connected on the slide rails. An electric control system is installed in the electric slide table, which slides on the slide rails through a control program. A square groove is opened on the inner side of the electric slide table, and a stop plate is slidably installed in the square groove. A screw is threaded to one end of the stop plate, and a motor is connected to the top of the screw. The motor is installed on the electric slide table through a connecting bracket. A through hole is opened on the stop plate, and multiple reinforcing abutments are evenly distributed in the through hole.

[0010] As a further technical solution, the rear support includes a rear base, on which a vertical beam is welded, and around the bottom of the vertical beam are reinforced ribs. An upper crossbeam is welded onto the vertical beam, and the upper crossbeam is connected to the leaf spring beam.

[0011] As a further technical solution, the leaf spring beam includes a connecting beam, which is connected to the front bracket and the rear bracket respectively. Supports are symmetrically installed on the connecting beam, and the front frame hanger and the rear frame hanger are installed on the support through ball joints. The front frame hanger and the rear frame hanger are connected to the frame.

[0012] As a further technical solution, the vehicle frame is equipped with a cab and accessory loading system and a power battery loading system. The cab and accessory loading system is located at the front of the vehicle frame, and the power battery loading system is located in the middle of the vehicle frame. The accessory loading system includes a cab counterweight block, and the power battery loading system includes a connecting plate. Two connecting plates are located on the front and rear sides of the vehicle frame, and a crossbeam is welded between the two connecting plates. Connecting reinforcing ribs are welded to the bottom end of the crossbeam and the inner side of the connecting plate. The crossbeam carries the power battery counterweight block. The cab counterweight block and the power battery counterweight block are concave sheet steel plate counterweight blocks. A H-beam is installed on the vehicle frame through U-bolts and H-beam connecting plates. The H-beam includes longitudinal beams, and multiple short crossbeams are evenly welded between two longitudinal beams. A mounting plate is welded to the top of the welded connection between the longitudinal beams and the short crossbeams.

[0013] As a further technical solution, a gantry frame is also included. The gantry frame is located in the middle and rear of the vehicle frame. The gantry frame includes a base, on which columns are welded. Multiple column reinforcing ribs are welded to the bottom of the columns, and multiple mounting holes are provided on the columns. A top crossbeam is bolted between two columns. A cargo box loading system is installed between the gantry frame and the vehicle frame. The cargo box loading system includes H-beams, with both ends of the H-beams connected to the top crossbeam. Multiple air springs are installed between two H-beams arranged vertically. Pressure sensors are installed at the bottom of the air springs. A mounting plate is connected to the air springs. Electro-hydraulic servo actuators are installed on both sides of the top of the hollow support beam.

[0014] As a further technical solution, two electro-hydraulic servo actuators are installed on the mounting plate located in the middle of the H-beam.

[0015] A method for bench testing the fatigue performance of an electric truck frame includes the following steps:

[0016] Torsional fatigue test:

[0017] S1, Calculate the static load on the chassis: Calculate the weight of the cab and accessory loading system, the power battery loading system, and the cargo box loading system on the test chassis.

[0018] S2, Calculate the dynamic load for the frame torsional fatigue test: Calculate the static load of the front axle when the vehicle is fully loaded, find the frame torsional load when one side of the front wheel is suspended, and then multiply it by the dynamic load factor 1.5 to obtain the maximum dynamic fatigue load of the frame torsional load.

[0019] S3, install the test vehicle frame onto the test device, remove the side brackets on both sides of the main board, allowing the frame to rotate 120° around the torsion axis during the test.

[0020] S4, Apply static load: Load the cab counterweight and power battery counterweight at the corresponding positions, adjust the internal gas pressure of the six air springs, read the load values ​​of the six pressure sensors and sum them, and apply a uniform load of cargo box and cargo to the frame.

[0021] S5 uses two electro-hydraulic servo actuators to apply sinusoidal reverse vertical torsional fatigue loads symmetrically between 0 and the maximum dynamic load at the front wheel track spacing at both ends of the hollow support beam of the front bracket. The loading frequency is any frequency in the range of 0.5Hz-2Hz. The frame torsional fatigue test is carried out until the frame fails due to fatigue, and the frame torsional fatigue life test results are obtained.

[0022] A method for bench testing the fatigue performance of an electric truck frame includes the following steps:

[0023] Bending fatigue test:

[0024] S1, Calculate the static load on the chassis: Calculate the weight of the cab and accessory loading system, the power battery loading system, and the cargo box loading system on the test chassis.

[0025] S2, Calculate the dynamic load for the frame torsional fatigue test: Calculate the static load of the front axle when the vehicle is fully loaded, find the frame torsional load when one side of the front wheel is suspended, and then multiply it by the dynamic load factor 1.5 to obtain the maximum dynamic fatigue load of the frame torsional load.

[0026] S3, install the test vehicle frame onto the test device. In the electric truck frame fatigue performance bench test device, remove the two gantry frames, the H-beams connected to the gantry frames, the air springs and pressure sensors, and fix the positions of the two sides of the main board with the side brackets to constrain the frame to rotate 120° around the torsion axis during the test.

[0027] S4, Apply static load: Load cab counterweights and power battery counterweights at the corresponding positions;

[0028] S5, through two electro-hydraulic servo actuators, is installed on the mounting plates at both ends of the short crossbeam in the middle of the H-beam. A sinusoidal downward vertical bending fatigue load is applied between 0 and the maximum bending dynamic load, with the loading frequency being any frequency in the range of 0.5Hz-2Hz. The frame bending fatigue test is carried out until the frame fails due to fatigue, and the frame bending fatigue life test results are obtained.

[0029] The beneficial effects of this invention are:

[0030] By applying corresponding dynamic loads to the cab and accessory loading system and the power battery loading system respectively; adjusting the gas pressure in the six air springs through the cargo box loading system and reading the load values ​​by six pressure sensors, and using the H-beam to transfer the load, the overall uniform load on the cargo area of ​​the frame can be applied. It can also apply different loads to the frame of electric cargo trucks with different load capacities, avoiding the trouble caused by repeatedly increasing or decreasing the number of counterweights to apply the cargo box load, which can significantly improve the loading efficiency during the frame torsional fatigue bench test.

[0031] The side limiting structure in the front bracket is detachable and adjustable. When it is in the installed position, a frame bending fatigue test can be performed. When the side limiting structure is removed or adjusted, a frame torsional fatigue test can be performed. This achieves the goal of performing multiple frame performance tests with one set of testing equipment, simulating real vehicle conditions to the greatest extent, making the frame fatigue performance test results more accurate, and greatly saving the test equipment development cost.

[0032] The torsional load on the chassis when one front wheel is suspended is calculated by simulation. Then, the load is multiplied by a dynamic load factor of 1.5 to obtain the maximum dynamic fatigue load of the chassis torsion. This makes the calculation of chassis torsional fatigue load more scientific and reasonable. The loading frequency is specified as any frequency in the range of 0.5Hz-2Hz. Simulation prediction and bench testing of chassis fatigue performance can be carried out during the chassis product development and design stage and before the prototype is developed. This greatly reduces the complexity of the test and ensures the accuracy of chassis fatigue performance test results. Attached Figure Description

[0033] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0034] Figure 1 This is a schematic diagram of the isometric structure of the present invention;

[0035] Figure 2 This is a schematic diagram of the front support structure of the present invention;

[0036] Figure 3 This is an isometric schematic diagram of the side limiting structure of the present invention;

[0037] Figure 4 This is a schematic diagram of the rear support structure of the present invention;

[0038] Figure 5 This is a schematic diagram of the leaf spring beam structure of the present invention;

[0039] Figure 6 This is a schematic diagram of the gantry structure of the present invention;

[0040] Figure 7 This is a schematic diagram of the H-beam structure of the present invention;

[0041] Figure 8 This is a schematic diagram of the connecting frame structure of the present invention;

[0042] Figure 9 This is a schematic diagram of the vehicle frame structure of the present invention;

[0043] Figure 10 This is a schematic diagram of the frame torsional fatigue test of the present invention;

[0044] Figure 11 This is a schematic diagram of the frame bending fatigue test of the present invention.

[0045] The markings in the diagram are as follows: 100, front bracket; 110, front support; 111, front base plate; 112, concave vertical plate; 113, vertical plate reinforcing rib; 114, bearing upper seat; 115, bearing side cover; 120, torsion shaft; 130, main plate; 140, side bracket; 141, side base plate; 142, side vertical plate; 143, reinforcing rib one; 144, reinforcing rib two; 1401, slide rail; 1402, electric slide table; 1403, square groove; 1404, through hole. 1405. Support plate; 1406. Reinforcing support column; 1407. Motor; 1408. Screw; 1409. Connecting frame; 150. Connecting seat; 151. Lower connecting plate; 152. Lower column; 153. Upper connecting plate; 160. Hollow support beam; 200. Rear bracket; 201. Rear base; 202. Vertical beam; 203. Beam reinforcement rib; 204. Upper crossbeam; 300. Leaf spring beam; 301. Connecting beam; 302. Support; 303 304. Ball joint; 305. Front frame hanger; 306. Rear frame hanger; 407. Gantry frame; 401. Base; 402. Column; 403. Column reinforcing rib; 404. Top crossbeam; 500. Cargo box loading system; 501. Air spring; 502. Pressure sensor; 503. Electro-hydraulic servo actuator; 504. U-bolt; 505. H-beam connecting plate; 510. H-beam; 511. Longitudinal beam; 512. Short crossbeam; 513. Mounting plate; 600, Cab and accessory loading system; 601, Cab counterweight; 700, Power battery loading system; 701, Power battery counterweight; 710, Connecting plate; 711, Crossbeam; 713, Connecting reinforcing rib; 800, Frame; 801, Left longitudinal beam; 802, Right longitudinal beam; 803, Front crossbeam; 804, Second crossbeam; 805, Third crossbeam; 806, Fourth crossbeam; 807, Fifth crossbeam; 808, Rear crossbeam. Detailed Implementation

[0046] Example 1

[0047] like Figure 1 and Figure 9 As shown, the present invention provides a bench test device for fatigue performance of electric truck frame. The frame 800 includes a left longitudinal beam 801, a right longitudinal beam 802, a front crossbeam 803, a second crossbeam 804, a third crossbeam 805, a fourth crossbeam 806, a fifth crossbeam 807, and a rear crossbeam 808.

[0048] The chassis 800 is equipped with a front support 100 and a rear support 200 at its bottom. The front support 100 is located at the front of the chassis 800, and the rear support 200 is located at the rear of the chassis 800. Both the front support 100 and the rear support 200 are equipped with leaf spring beams 300, which are connected to the bottom of the chassis 800. The front support 100 supports the front of the chassis 800 through the leaf spring beams 300, and the rear support 200 supports the rear of the chassis 800 through the leaf spring beams 300. The use of the front support 100 and the rear support 200 to support the chassis 800 simulates the actual vehicle working conditions to the greatest extent, making the chassis fatigue performance test results more accurate.

[0049] like Figure 5 As shown, specifically, the leaf spring beam 300 includes a connecting beam 301, which is connected to the front support 100 and the rear support 200 respectively, as... Figure 4 As shown, the rear support 200 is fixedly installed on the ground rail by bolt connection. The rear support 200 includes a rear base 201, on which a vertical beam 202 is welded. The bottom of the vertical beam 202 is welded with beam reinforcing ribs 203. The stability of the bottom of the rear support 200 is ensured by multiple beam reinforcing ribs 203, making it more stable in supporting the frame 800. An upper crossbeam 204 is welded on the vertical beam 202 to form a π-shaped support structure. The upper crossbeam 204 is connected to the leaf spring beam 300.

[0050] Symmetrical supports 302 are mounted on the connecting beam 301. Front and rear frame hangers 304 and 305 are mounted on the supports 302 via ball joints 303, allowing the frame to rotate in three directions when subjected to load deformation. The front and rear frame hangers 304 and 305 are connected to the frame 800. Figure 1 As shown, the front and rear ends of the frame 800 are equipped with a front frame hanger 304 and a rear frame hanger 305, and the frame 800 is stably supported by multiple leaf spring beams 300 to ensure the smooth conduct of the fatigue performance test of the frame 800.

[0051] Example 2

[0052] Based on the above embodiment one, as follows Figure 1 and Figure 8As shown, a cab and accessory loading system 600 and a power battery loading system 700 are installed on the frame 800. The cab and accessory loading system 600 and the power battery loading system 700 respectively apply corresponding loads to the frame 800. Specifically, the cab and accessory loading system 600 is located at the front of the frame 800, and the power battery loading system 700 is located in the middle of the frame 800. The cab and accessory loading system 600 includes a cab counterweight 601, and the power battery loading system 700 includes connecting plates 710. The two connecting plates 710 are located on the front and rear sides of the frame 800. A crossbeam 711 is welded between the connecting plates 710. A connecting reinforcing rib 713 is welded to the bottom of the crossbeam 711 and the inner side of the connecting plate 710. The crossbeam 711 carries a power battery counterweight 701. The cab counterweight 601 and the power battery counterweight 701 are concave sheet steel plate counterweights. By loading the load through the cab counterweight 601 and the power battery counterweight 701, the number of counterweights can be adjusted according to the required loading requirements, which is conducive to installation and fastening. This allows different loads to be applied to the frame of electric trucks with different load capacities, significantly improving the loading efficiency during the frame torsional fatigue bench test.

[0053] Example 3

[0054] Based on the above-described embodiment two, in order to conduct a torsional fatigue test on the frame 800, such as Figures 1-3 As shown, the front support 100 includes a front support 110, which includes a front base plate 111. A concave vertical plate 112 is welded onto the front base plate 111. Reinforcing ribs 113 are welded to the front and rear sides of the concave vertical plate 112 to enhance its stability. A torsion shaft 120 is mounted on the concave vertical plate 112. A bearing upper seat 114 is also mounted on the concave vertical plate 112, located above the torsion shaft 120. Both ends of the bearing upper seat 114 are connected to the concave vertical plate 112. The top of the concave upright plate 112 is fixedly connected. The bearing upper seat 114 and the bearing side cover 115 are installed on one side of the concave upright plate 112. The bearing side cover 115 is located on one side of the torsion shaft 120. The concave upright plate 112, the bearing upper seat 114 and the bearing side cover 115 form a hollow area. The torsion shaft 120 extends to the outside through the hollow area. The main plate 130 is connected to the torsion shaft 120. The main plate 130 can rotate around the torsion shaft 120. Therefore, the front support 110 and the main plate 130 are hinged.

[0055] Furthermore, the main board 130 is connected to the torsion shaft 120, and the top of the main board 130 is connected to the leaf spring beam 300. Side limiting structures are movably installed at both ends of the main board 130. The side limiting structures are used to constrain the main board 130 to rotate around the torsion shaft 120. In actual testing, when the side limiting structures on both sides of the main board 130 are removed, the main board 130 can rotate around the torsion shaft 120, thereby conducting a torsional fatigue test on the frame 800. Conversely, when the side limiting structures are installed on both sides of the main board 130 and abut against both sides of the main board 130, the main board 130 cannot rotate around the torsion shaft 120.

[0056] Furthermore, a connector 150 is installed on the main board 130, and a hollow support beam 160 is installed on the connector 150. The hollow support beam 160 is connected to the leaf spring beam 300. The connector 150 includes a lower connecting plate 151, which is installed on the main board 130. A lower column 152 is welded to the lower connecting plate 151, and an upper connecting plate 153 is welded to the top of the lower column 152. A T-shaped groove is opened at the bottom of the hollow support beam 160, and the upper connecting plate 153 is slidably connected to the T-shaped groove.

[0057] Example 4

[0058] Based on the above embodiment three, as follows Figure 2 As shown, the side limiting structure includes a side bracket 140, the side bracket 140 includes a side base plate 141, a side upright plate 142 is welded on the side base plate 141, the top of the side upright plate 142 abuts against both sides of the main plate 130, a first reinforcing rib 143 is welded on the left and right sides of the side upright plate 142, and a second reinforcing rib 144 is welded on the front and rear sides of the side upright plate 142.

[0059] like Figure 1 As shown, both the side base plate 141 and the front base plate 111 are bolted to the ground plate. Therefore, when it is necessary to remove the side upright plate 142, the side base plate 141 can be directly removed from the ground plate. Conversely, when it is necessary to restrict the rotation of the main plate 130, the side base plate 141 can be fixed to the ground plate by bolting.

[0060] Example 5

[0061] Based on the above embodiment three, in order to further facilitate the limiting adjustment of the side limiting structure on the motherboard 130, such as... Figure 3As shown, the side limiting structure includes a side base plate 141, which is fixed to the ground iron by bolts. A slide rail 1401 is symmetrically arranged on the side base plate 141, and an electric slide table 1402 is slidably connected to the slide rail 1401. An electric control system is installed inside the electric slide table 1402, which can slide on the slide rail 1401 via a control program. A square groove 1403 is formed inside the electric slide table 1402, and a stop plate 1405 is slidably installed in the square groove 1403. A screw rod 1408 is threaded to one end of the stop plate 1405, and a motor 1407 is connected to the top of the screw rod 1408. The side limiting structure is installed on the electric slide table 1402 via the connecting bracket 1409. During use, there is no need to install or remove the entire side limiting structure. When it is necessary to abut against the main board 130, the screw 1408 is rotated by the motor 1407, which causes the abutment plate 1405 to move up and down. The electric slide table 1402 moves along the slide rail 1401, which causes the abutment plate 1405 to move left and right. The up and down and left and right movements of the abutment plate 1405 make it accurately abut against the main board 130. Furthermore, the abutment plate 1405 is provided with a through hole 1404, and multiple reinforcing abutment posts 1406 are evenly distributed in the through hole 1404 to improve the strength of the abutment plate 1405.

[0062] Example 6

[0063] Based on the above embodiment five, such as Figures 1-9 and Figure 11As shown, a H-beam 510 is mounted on the frame 800 via U-bolts 504 and a H-beam connecting plate 505. The bending and torsional stiffness of the H-beam 510 is the same as that of the subframe, serving to evenly distribute the cargo load in the cargo box. The H-beam 510 includes longitudinal beams 511, with multiple short crossbeams 512 evenly welded between two longitudinal beams 511. A mounting plate 513 is welded to the top of the welded connection between the longitudinal beams 511 and the short crossbeams 512. The width of the longitudinal beam 511 is equal to the width of the upper flange of the frame longitudinal beam, and its length can cover the cargo area of ​​the frame assembly. The H-beam 510 is located at... Two electro-hydraulic servo actuators 503 are mounted on the mounting plate 513 in the middle of the H-beam 510 to conduct bending fatigue tests on the chassis. Specifically, the static load of the chassis 800 is calculated: the weight of the cab and accessory loading system 600, the power battery loading system 700, and the cargo box loading system 500 on the test chassis are calculated; the dynamic load of the chassis 800 for torsional fatigue testing is calculated: the static load of the front axle under full load is calculated, the torsional load of the chassis 800 when one front wheel is suspended is obtained, and then multiplied by the dynamic load factor 1.5. Obtain the maximum dynamic fatigue load of the chassis under torsion; install the test chassis onto the test apparatus. In the electric truck chassis fatigue performance bench test apparatus, remove the two gantry frames 400, the H-beam 510 connected to the gantry frames 400, the air spring 501, and the pressure sensor 502. The air spring 501 is used to apply the cargo load of the cargo box, and the pressure sensor 502 is used to monitor the load magnitude. Fix the positions of the main board 130 on both sides with the side bracket 140 to constrain the chassis 800 to rotate around the torsion axis 120° during the test; apply static load: The cab counterweight 601 and the power battery counterweight 701 are installed at the corresponding positions. Two electro-hydraulic servo actuators 503 are installed on the mounting plates 513 at both ends of the short crossbeam 512 in the middle of the H-beam 510. A sinusoidal downward vertical bending fatigue load is applied between 0 and the maximum bending dynamic load. The loading frequency is any frequency in the range of 0.5Hz-2Hz. The bending fatigue test of the frame 800 is carried out until the frame 800 fails due to fatigue. The bending fatigue life test results of the frame 800 are obtained.

[0064] Example 7

[0065] Based on the above-described embodiment five, the electric truck frame fatigue performance test bench device, such as... Figures 1-10As shown, it also includes a gantry frame 400, which is bolted to the ground rail. The gantry frame 400 is located in the middle and rear of the frame 800. The gantry frame 400 includes a base 401, on which columns 402 are welded. Multiple column reinforcing ribs 403 are welded to the bottom of the columns 402. Multiple mounting holes are provided on the columns 402. A top crossbeam 404 is bolted between two columns 402. The mounting height of the top crossbeam 404 can be adjusted as needed through the multiple mounting holes. A cargo box loading system 500 is installed between the gantry frame 400 and the frame 800. The cargo box loading system 500 includes a H-beam 510. The H-beam 510 has two... The ends are connected to the top crossbeam 404 respectively. Multiple air springs 501 are installed between the two vertically arranged H-beams 510. Pressure sensors 502 are installed at the bottom of each air spring 501. The mounting plate 513 is connected to the air springs 501. The upper ends of the six air springs 501 are fixed by the upper H-beams 510. Pressure sensors 502 are installed at the lower ends of the air springs 501, and their upward movement is constrained by the front and rear gantry frames 400. By adjusting the inflation pressure of the six air springs 501, different cargo loads on the chassis 800 can be applied, avoiding the hassle of repeatedly adding or removing counterweights and improving the loading efficiency of the test bench. The hollow support beam 160 has two sides at its top. Electro-hydraulic servo actuators 503 are installed to perform torsional fatigue tests on the chassis 800. The static load on the chassis 800 is calculated by: calculating the weight of the cab and accessory loading system 600, the power battery loading system 700, and the cargo box loading system 500 on the chassis under test; the dynamic load of the chassis 800 for torsional fatigue testing is calculated by: calculating the static load of the front axle under full load, determining the torsional load on the chassis 800 when one front wheel is suspended, and multiplying this by a dynamic load factor of 1.5 to obtain the maximum dynamic fatigue load of the chassis under torsion; the chassis under test is installed on the testing device, and the side supports 140 on both sides of the main board 130 are removed, allowing the chassis 800 to rotate 120° around the torsion axis during the test; static load is applied. Load: Load the cab counterweight 601 and the power battery counterweight 701 at the corresponding positions. By adjusting the internal gas pressure of the six air springs 501, read the load values ​​of the six pressure sensors 502 and sum them to apply a uniform load of cargo box and cargo to the frame. Through two electro-hydraulic servo actuators 503, apply a sinusoidal reverse vertical torsional fatigue load symmetrically between 0 and the maximum dynamic load at the front wheel track spacing width at both ends of the hollow support beam 160 of the front bracket 100. The loading frequency is any frequency in the range of 0.5Hz-2Hz. Perform a torsional fatigue test on the frame 800 until the frame 800 fails due to fatigue. Obtain the torsional fatigue life test results of the frame 800.

[0066] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A bench test apparatus for fatigue performance of an electric truck frame, comprising a frame (800), characterized in that, The frame (800) has a front support (100) and a rear support (200) mounted on its bottom. The front support (100) is located at the front of the frame (800), and the rear support (200) is located at the rear of the frame (800). Both the front support (100) and the rear support (200) are equipped with leaf spring beams (300), which are connected to the bottom of the frame (800). The front support (100) includes a front support (110), which includes a torsion shaft (120) and a main... The main plate (130) is connected to the torsion shaft (120). The top of the main plate (130) is connected to the leaf spring beam (300). Side limiting structures are movably installed at both ends of the main plate (130). The side limiting structures are used to constrain the main plate (130) to rotate around the torsion shaft (120). The side limiting structures in the front bracket (100) are detachable and adjustable. When in the installation position, the frame bending fatigue test can be carried out. When the side limiting structures are removed or adjusted, the frame torsional fatigue test can be carried out. It also includes a gantry frame (400), which is located in the middle and rear of the frame (800). The gantry frame (400) includes a base (401), on which columns (402) are welded. Multiple column reinforcing ribs (403) are welded to the bottom of the columns (402). Multiple mounting holes are provided on the columns (402). A top crossbeam (404) is bolted between two columns (402). A cargo loading system (500) is installed between the gantry frame (400) and the frame (800). The cargo box loading system (500) includes a H-beam (510), with both ends of the H-beam (510) connected to a top crossbeam (404). Multiple air springs (501) are installed between the two H-beams (510) arranged vertically. A pressure sensor (502) is installed at the bottom of the air spring (501). A mounting plate (513) is connected to the air spring (501). Electro-hydraulic servo actuators (503) are installed on both sides of the top of the hollow support beam (160). The hollow support beam (160) is connected to the leaf spring beam (300).

2. The bench test apparatus for fatigue performance of electric truck chassis according to claim 1, characterized in that, The frame (800) includes a left longitudinal beam (801), a right longitudinal beam (802), a front crossbeam (803), a second crossbeam (804), a third crossbeam (805), a fourth crossbeam (806), a fifth crossbeam (807), and a rear crossbeam (808). The front support (110) also includes a front base plate (111). A concave vertical plate (112) is welded onto the front base plate (111), and vertical plate reinforcing ribs (113) are welded to the front and rear sides of the concave vertical plate (112). The torsion shaft (120) is mounted on the concave vertical plate (112), and a bearing seat (114) is also mounted on the concave vertical plate (112). The bearing seat (114) is located above the torsion shaft (120). 4) A bearing side cover (115) is installed on one side of the concave upright plate (112). The bearing side cover (115) is located on one side of the torsion shaft (120). The main plate (130) is connected to the torsion shaft (120). A connecting seat (150) is installed on the main plate (130). A hollow support beam (160) is installed on the connecting seat (150). The connecting seat (150) includes a lower connecting plate (151). The lower connecting plate (151) is installed on the main plate (130). A lower column (152) is welded on the lower connecting plate (151). An upper connecting plate (153) is welded to the top of the lower column (152). A T-shaped groove is opened at the bottom of the hollow support beam (160). The upper connecting plate (153) is slidably connected to the T-shaped groove.

3. The bench test apparatus for fatigue performance of electric truck chassis according to claim 2, characterized in that, The side limiting structure includes a side bracket (140), the side bracket (140) includes a side base plate (141), a side upright plate (142) is welded on the side base plate (141), the top of the side upright plate (142) abuts against both sides of the main plate (130), a first reinforcing rib (143) is welded on the left and right sides of the side upright plate (142), and a second reinforcing rib (144) is welded on the front and rear sides of the side upright plate (142).

4. The bench test apparatus for fatigue performance of electric truck chassis according to claim 2, characterized in that, The side limiting structure includes a side base plate (141), which is fixed to the ground iron by bolts. A slide rail (1401) is symmetrically arranged on the side base plate (141). An electric slide table (1402) is slidably connected to the slide rail (1401). An electric control system is installed inside the electric slide table (1402), and the electric slide table (1402) slides on the slide rail (1401) through a control program. A square groove (1402) is provided on the inner side of the electric slide table (1402). 03), a stop plate (1405) is slidably installed in the square groove (1403). A screw rod (1408) is threaded to one end of the stop plate (1405). A motor (1407) is connected to the top of the screw rod (1408). The motor (1407) is installed on the electric slide table (1402) through the connecting bracket (1409). A through hole (1404) is opened on the stop plate (1405). Multiple reinforcing abutment posts (1406) are evenly distributed in the through hole (1404).

5. The bench test apparatus for fatigue performance of electric freight vehicle frames according to claim 3 or 4, characterized in that, The rear support (200) includes a rear base (201), on which a vertical beam (202) is welded. A beam reinforcing rib (203) is welded around the bottom of the vertical beam (202). An upper crossbeam (204) is welded on the vertical beam (202). The upper crossbeam (204) is connected to the leaf spring beam (300). The leaf spring beam (300) includes a connecting beam (301). The connecting beam (301) is connected to the front support (100) and the rear support (200) respectively. A support (302) is symmetrically installed on the connecting beam (301). A front frame hanger (304) and a rear frame hanger (305) are installed on the support (302) through a ball joint (303). The front frame hanger (304), the rear frame hanger (305) and the frame (800) are connected.

6. The bench test apparatus for fatigue performance of electric truck chassis according to claim 5, characterized in that, The chassis (800) is equipped with a cab and accessory loading system (600) and a power battery loading system (700). The cab and accessory loading system (600) is located at the front of the chassis (800), and the power battery loading system (700) is located in the middle of the chassis (800). The cab and accessory loading system (600) includes a cab counterweight (601), and the power battery loading system (700) includes a connecting plate (710). The two connecting plates (710) are located on the front and rear sides of the chassis (800), and a crossbeam (711) is welded between the two connecting plates (710). The bottom end of the crossbeam (711) and The inner side of the connecting plate (710) is welded with connecting reinforcing ribs (713). The crossbeam (711) carries the power battery counterweight block (701). The cab counterweight block (601) and the power battery counterweight block (701) are concave sheet steel plate counterweight blocks. The frame (800) is equipped with a H-beam (510) by U-bolts (504) and H-beam connecting plate (505). The H-beam (510) includes a longitudinal beam (511). Multiple short crossbeams (512) are evenly welded between the two longitudinal beams (511). The top of the welded connection between the longitudinal beam (511) and the short crossbeam (512) is welded with an mounting plate (513).

7. The bench test apparatus for fatigue performance of electric truck chassis according to claim 6, characterized in that, in, Two electro-hydraulic servo actuators (503) are installed on the mounting plate (513) located in the middle of the H-beam (510).

8. A method for using the bench test apparatus for fatigue performance of electric truck frames as described in claim 7, characterized in that, Includes the following steps: Torsional fatigue test: S1, calculate the static load of the chassis (800): calculate the weight of the cab and accessory loading system (600), the power battery loading system (700) and the cargo box loading system (500) on the test chassis. S2, calculate the dynamic load of the frame (800) torsional fatigue test: calculate the static load of the front axle when the whole vehicle is fully loaded, find the torsional load of the frame (800) when the front wheel on one side is suspended, and then multiply it by the dynamic load coefficient 1.5 to obtain the maximum dynamic fatigue load of the frame torsion. S3, install the test vehicle frame onto the test device, remove the side brackets (140) on both sides of the main board (130), and allow the frame (800) to rotate 120° around the torsion axis during the test; S4, Apply static load: Load cab counterweight (601) and power battery counterweight (701) at the corresponding positions, and apply uniform load of cargo box and cargo to the frame by adjusting the internal gas pressure of six air springs (501), reading the load values ​​of six pressure sensors (502) and summing them. S5, through two electro-hydraulic servo actuators (503), a sinusoidal reverse vertical torsional fatigue load is symmetrically applied at the front wheel track spacing width at both ends of the hollow support beam (160) of the front bracket (100) between 0 and the maximum dynamic load, and the loading frequency is any frequency in the range of 0.5Hz-2Hz, to conduct a torsional fatigue test on the frame (800) until the frame (800) fails due to fatigue, and the torsional fatigue life test result of the frame (800) is obtained.

9. A method for using the bench test apparatus for fatigue performance of electric truck frames as described in claim 8, characterized in that, Includes the following steps: Bending fatigue test: S1, calculate the static load of the chassis (800): calculate the weight of the cab and accessory loading system (600), the power battery loading system (700) and the cargo box loading system (500) on the test chassis. S2, calculate the dynamic load of the frame (800) torsional fatigue test: calculate the static load of the front axle when the whole vehicle is fully loaded, find the torsional load of the frame (800) when the front wheel on one side is suspended, and then multiply it by the dynamic load coefficient 1.5 to obtain the maximum dynamic fatigue load of the frame torsion. S3, install the test vehicle frame onto the test device. In the electric truck frame fatigue performance bench test device, remove the two gantry frames (400), the H-beam (510) connected to the gantry frames (400), the air spring (501) and the pressure sensor (502), fix the positions of the two sides of the main board (130) with the side bracket (140), and constrain the frame (800) to rotate 120° around the torsion axis during the test; S4, Apply static load: Load cab counterweight (601) and power battery counterweight (701) at the corresponding positions. S5, by means of two electro-hydraulic servo actuators (503), installed on the mounting plates (513) at both ends of the short crossbeam (512) in the middle position of the H-beam (510), a sinusoidal downward vertical bending fatigue load is applied between 0 and the maximum bending dynamic load, and the loading frequency is any frequency in the range of 0.5Hz-2Hz, and the frame (800) bending fatigue test is carried out until the frame (800) fails due to fatigue, and the bending fatigue life test result of the frame (800) is obtained.

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