Loading device of automobile tire road test trailer and test method thereof

Abstract

The invention relates to a loading device of an automobile tire road test trailer and a test method thereof. Comprising an axle, a leveling assembly, a vertical loading assembly and a test tire, a rotating wheel below the axle abuts against the road surface, the rear portion of the leveling assembly is rotatably connected to a rack above the axle, and the vertical loading assembly is arranged in front of the leveling assembly and keeps perpendicular to the road surface. The test tire is detachably connected below the vertical loading assembly and abuts against the road surface. According to the invention, high-precision vertical loading is carried out on the tire for testing the relative gripping performance of the automobile tire on the wet road surface, and longitudinal force errors caused by inaccurate vertical road surface loading are eliminated, so that the testing precision of the relative gripping performance of the tire on the wet road surface is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of tire relative grip performance testing, and in particular relates to a loading device of a road test trailer for automobile tires and a testing method thereof. Background Art

[0002] Tires are the most important safety components of automobiles and the only ground-connected components. Tire grip performance is very important to the handling and safety performance of tires and vehicles, especially braking performance. There is no consistency between tire dry grip and wet grip performance, and they need to be tested separately. On wet roads, due to the significant reduction in the adhesion between tires and the ground, vehicles are prone to dangerous situations such as skidding and loss of control, which increases the safety risks of traffic accidents. Therefore, all vehicle and tire companies attach great importance to the relative grip performance test of tires on wet roads, which is used to guide the development and matching of tire braking performance; at the same time, national regulations and standards also attach great importance to the relative grip performance of tires on wet roads, and have successively promulgated GB / T 21910 "Test Method for Relative Grip Performance of Passenger Car Tires on Wet Roads" and GB / T 35163 "Test Method for Relative Grip Performance of Truck Tires on Wet Roads", and the national mandatory standards GB 9743-2024 "Passenger Car Tires" and GB 9744-2024 "Truck Tires" promulgated in 2024 clearly include tire wet road grip performance in mandatory management requirements. These demands require not only perfect technical standards and test sites, but also precise testing instruments and equipment.

[0003] Compared with dry-road testing, it is more difficult to achieve consistency in wet-road testing. Test results may be different at different sites, different locations at the same site, or at the same location at different times. Therefore, it is necessary to introduce standard tires with stable performance and good consistency, and evaluate the wet-road grip performance of the tire to be tested by comparing the wet grip performance of the tire to the standard tire.

[0004] The wet road grip performance test methods of this type of tire currently include the vehicle method and the trailer method. The vehicle method selects a test vehicle equipped with an ABS system that is suitable for both the tire to be tested and the standard tire, tests the tire to be tested and the standard tire separately, and uses instruments to test the deceleration performance of the tire during braking. The disadvantages of the vehicle method are: first, the specifications of standard tires are limited, and many tires to be tested cannot be installed on the same test vehicle as the standard tires for testing, and even with the help of reference tires (third tires) for transition, some tire specifications are also difficult to test using the vehicle method; second, the test efficiency is low and the cost is high. In addition, the vehicle method can only obtain the average deceleration, braking force coefficient and wet road relative grip performance index of the tire to be tested, and is powerless for key data such as tire peak braking force, braking peak adhesion coefficient, braking slip adhesion coefficient and slip rate that the automotive industry is concerned about.

[0005] The trailer method is to install a test tire (including the tire to be tested and the standard tire. Taking the car tire as an example, the vehicle method requires four tires to be installed at the same time) on a special test trailer towed by a tractor, and install the tire to be tested on the trailer, or install the tire to be tested on a special tire test vehicle. When it passes the test road surface at a specified speed, the maximum braking force of the tire from the start of emergency braking to the time when the wheel is locked is measured by a multi-component force sensor installed on the tire axle (the measurement components include but are not limited to the vertical direction and the longitudinal direction), thereby obtaining the (instantaneous) braking force, (instantaneous) test load, (instantaneous) braking force coefficient, peak braking force, braking peak adhesion coefficient, braking slip adhesion coefficient and slip rate, etc. The trailer method can meet the needs of both the tire industry and the automotive industry.

[0006] The vertical loading mechanism of the test trailer is an important part of the tire's relative grip performance test on wet roads. Early test trailers vertically loaded the tires by adding weights to the vehicle (such as iron sand bags, weights, etc.), which was bulky and inconvenient. In the prior art, mechanical levers are used to implement vertical tire loading. The counterweights are placed on the crossbeam, and the position of the counterweights is adjusted by the motor system. The lever principle is used to vertically load the test tires. However, due to the different radii of the test tires, the crossbeam and the ground cannot be parallel, and their angle is related to the dynamic load radius of the tire. According to the principle of force and moment balance, the component of the weight of the weight parallel to the crossbeam is balanced by the traction provided by the traction motor, and the vertical component acting on the crossbeam acts on the ground through the tire, causing the tire to be subjected to the vertical and longitudinal (tangential) reaction forces of the ground. In order to distinguish the difference between the longitudinal (tangential) force caused by the insufficient vertical loading accuracy and the tire braking force, it is called additional longitudinal force, such as Figure 1 shown.

[0007] In the tire wet road relative grip performance test, although the influence of the above-mentioned additional longitudinal force on the measuring sensor can be eliminated by "resetting" the sensor to zero, the tire's own performance determines its longitudinal adhesion limit. Due to the existence of the additional longitudinal force, the peak braking force measured by the tire may be too small (if the direction of the additional longitudinal force is the same as the braking force) or too large (if the direction of the additional longitudinal force is opposite to the braking force). Therefore, it is necessary to take technical measures to correct the test error caused by insufficient vertical accuracy of the test trailer loading. Summary of the invention

[0008] In order to solve the above technical problems, the present invention provides a loading device for a car tire road test trailer and a testing method thereof, which performs high-precision vertical loading on the tires for testing the relative grip performance of car tires on wet roads, thereby eliminating the longitudinal force error caused by the inability to load accurately perpendicular to the road surface, thereby improving the accuracy of the tire wet road relative grip performance test.

[0009] To achieve the above object, the technical solution adopted by the present invention is:

[0010] A loading device for a car tire road test trailer comprises an axle, a leveling assembly, a vertical loading assembly and a test tire, wherein a rotating wheel below the axle abuts against the road surface, the rear portion of the leveling assembly is rotatably connected to a frame above the axle, the vertical loading assembly is arranged at the front portion of the leveling assembly and is kept in a vertical state with the road surface, and the test tire is detachably connected to the bottom of the vertical loading assembly and abuts against the road surface.

[0011] The leveling assembly includes a crossbeam, a first slide rail, a loading seat, a weight, an angle sensor and a driving component. The crossbeam is rotatably connected to the frame, the first slide rail is laid on the crossbeam, the loading seat is slidably connected to the first slide rail at the bottom, and the weight is detachably mounted on the loading seat; the angle sensor is arranged on the crossbeam; the driving component is arranged on the crossbeam, and the loading seat slides on the first slide rail driven by the driving component.

[0012] The vertical loading assembly is vertically installed on one side of the crossbeam, and the vertical loading assembly includes a servo motor, a test wheel position, a multi-component force sensor and a brake. The servo motor is arranged on the crossbeam and connected to the test wheel position through the multi-component force sensor. The test wheel position adjusts the up and down height position under the drive of the servo motor. The test tire is detachably connected to the test wheel position, and the brake is arranged on the test wheel position.

[0013] Furthermore, the vertical loading assembly also includes a support plate, a second slide rail and a support seat, the support plate is connected below the cross beam, the second slide rail is arranged on the support plate, the support seat slides on the second slide rail driven by a servo motor, and the support seat is connected to the test wheel position through a multi-component force sensor.

[0014] Furthermore, the vertical loading assembly also includes a fixed plate and a third slide rail, the third slide rail is arranged on the fixed plate, the fixed plate is slidably connected to the mounting seat on the beam through the third slide rail, the output end of the servo motor is connected to the fixed plate, and the test wheel position is connected to the fixed plate through a multi-component force sensor.

[0015] The present invention also provides a loading test method for a vehicle tire road test trailer, comprising the following steps:

[0016] S1: Hang the axle at the rear of the test trailer so that its rotating wheels are in contact with the road surface, install the test tires on the test wheel positions and let the test tires contact the road surface;

[0017] S2: Drive the servo motor to adjust the vertical position of the test wheel, and cooperate with the angle sensor to ensure that the beam remains horizontal;

[0018] S3: Set the vertical force required to load the vertical load on the test tire to Fz, set the weight of the weight to Mg, set the distance between the weight and the articulation axis to L1, set the distance between the test wheel position and the articulation axis to L2, and meet the requirements. Calculate the formula of

[0019] S4: When the weight Mg and the distance L2 between the test wheel and the articulated axis are fixed values, the driving component is started, and the lateral position of the weight on the beam is adjusted through the driving form of the motor, the reducer, and the gear rack, so as to change the value of L1, and finally change the actual vertical load value collected by the multi-component force sensor until its value reaches the required vertical force Fz; the weight can be added as needed, so as to change the size of Mg, so as to adapt to the vertical load requirements of different test tires;

[0020] S5: When the test trailer passes the test road surface at a constant speed at a specified speed, the maximum braking force of the tire from the start of emergency braking to the moment when the wheel is locked is measured by a multi-component force sensor.

[0021] Compared with the prior art, the advantages of the present invention are: in order to meet the requirements of accurate vertical loading of the test tire and ensuring that its longitudinal component is zero, the test wheel position is pushed downward by the servo motor, so that the crossbeam installed by the servo motor rotates upward with the hinge axis as the rotation center under the reverse force, and the vertical position of the test tire is adjusted. In conjunction with the angle sensor, the angle sensor feedback signal is made to be 0°, ensuring that the crossbeam is on a horizontal line, and the gravity of the weight acts vertically on the crossbeam, ensuring that the additional longitudinal force in the ground reaction force received by the test tire is zero. Therefore, there is no need to eliminate the influence of the additional longitudinal force on the measuring sensor by "returning to zero", thereby improving the accuracy of the relative grip performance test of the test tire on a wet road. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 The background technology of the present invention is a schematic diagram of the force analysis of a tire under the action of a vertical loading mechanism in the prior art;

[0024] Figure 2 It is a stereogram of embodiment 1 of the present invention;

[0025] Figure 3 This is a three-dimensional view of the embodiment 1 of the present invention after the test tire is hidden;

[0026] Figure 4 It is a top view of embodiment 1 of the present invention;

[0027] Figure 5 For the present invention Figure 4 AA section view;

[0028] Figure 6 For the present invention Figure 4 BB cross-sectional view;

[0029] Figure 7 It is a left view of embodiment 1 of the present invention;

[0030] Figure 8 It is a schematic diagram of force analysis symbols of the present invention;

[0031] Fig. 9 It is a stereoscopic diagram of embodiment 2 of the present invention.

[0032] Among them: 1. Axle; 11. Frame; 2. Leveling assembly; 21. Crossbeam; 211. Articulated shaft; 212. Mounting seat; 22. First slide rail; 23. Loading seat; 24. Weight; 25. Angle sensor; 26. Driving component; 3. Vertical loading assembly; 31. Servo motor; 32. Test wheel position; 33. Multi-component force sensor; 34. Support plate; 35. Second slide rail; 36. Support seat; 37. Fixed plate; 38. Third slide rail; 39. Brake; 4. Test tire. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0034] The specific implementation of the present invention will be described below in conjunction with the accompanying drawings:

[0035] Example 1

[0036] like Figure 2-8 As shown, a loading device for a vehicle tire road test trailer includes an axle 1, a leveling component 2, a vertical loading component 3 and a test tire 4, wherein the rotating wheel below the axle 1 abuts against the road surface, the rear portion of the leveling component 2 is rotatably connected to a frame 11 above the axle 1, the vertical loading component 3 is arranged at the front portion of the leveling component 2 and maintained in a vertical state with the road surface, and the test tire 4 is detachably connected to the bottom of the vertical loading component 3 and abuts against the road surface.

[0037] The leveling assembly 2 includes a crossbeam 21, a first slide rail 22, a loading seat 23, a weight 24, an angle sensor 25 and a driving member 26. One end of the crossbeam 21 is rotatably connected to the frame 11 via a hinge shaft 211. The first slide rail 22 is laid on the upper end surface of the crossbeam 21. The lower part of the loading seat 23 is slidably connected to the first slide rail 22. The weight 24 is detachably mounted on the loading seat 23. The angle sensor 25 is arranged on the crossbeam 21. The driving member 26 is arranged on the crossbeam 21. The loading seat 23 slides on the first slide rail 22 driven by the driving member 26.

[0038] The vertical loading component 3 is vertically installed on one side of the crossbeam 21. The vertical loading component 3 includes a servo motor 31, a test wheel position 32, a multi-component force sensor 33 and a brake 39. The servo motor 31 is set on the crossbeam 21 and connected to the test wheel position 32 through the multi-component force sensor 33. The test wheel position 32 is adjusted up and down under the drive of the servo motor 31. The test tire 4 is detachably connected to the test wheel position 32, and the brake 39 is set on the test wheel position 32.

[0039] The vertical loading assembly 3 also includes a support plate 34, a second slide rail 35 and a support seat 36. The support plate 34 is connected below the cross beam 21. The second slide rail 35 is arranged on the support plate 34. The support seat 36 slides on the second slide rail 35 driven by the servo motor 31. The support seat 36 is connected to the test wheel position 32 through a multi-component force sensor 33.

[0040] The present invention also provides a loading test method for a vehicle tire road test trailer, comprising the following steps:

[0041] S1: The vehicle axle 1 is mounted on the rear of the test trailer so that its rotating wheels are in contact with the road surface, and the test tire 4 is installed on the test wheel position 32 and the test tire 4 is in contact with the road surface;

[0042] S2: driving the servo motor 31 to adjust the vertical position of the test wheel 32, and cooperating with the angle sensor 25 to ensure that the crossbeam 21 remains horizontal;

[0043] S3: Set the vertical force required to load the vertical load on the test tire 4 to Fz, set the weight of the weight 24 to Mg, set the distance between the weight 24 and the articulation axis 211 to L1, set the distance between the test wheel position 32 and the articulation axis 211 to L2, and meet Calculate the formula of

[0044] S4: When the weight Mg of the weight 24 and the distance L2 between the test wheel position 32 and the hinge shaft 211 are fixed values, the driving component 26 is started, and the lateral position of the weight 24 on the crossbeam 21 is adjusted through the driving form of the motor, the reducer, and the gear rack, so as to change the value of L1, and finally change the actual vertical load value collected by the multi-component force sensor 33, until the value reaches the required vertical force Fz; the weight 24 can be added as needed, so as to change the size of Mg, so as to adapt to the vertical load requirements of different test tires 4;

[0045] S5: When the test trailer passes the test road surface at a constant speed at a specified speed, the maximum braking force of the tire from the start of emergency braking of the brake 39 to the moment when the wheel is locked is measured by the multi-component force sensor 33.

[0046] Description of the working method of the present invention:

[0047] The loading device of the automobile tire road test trailer adopting this structure is composed of an axle 1, a leveling component 2, a vertical loading component 3 and a test tire 4. The rotating wheel under the axle 1 is a driven wheel, and its function is to keep the axle 1 stable when the test trailer is dragged through the test road surface. The crossbeam 21 can be rotatably connected to the frame 11 above the axle 1. More preferably, the crossbeam 21 can be connected to the frame 11 in the form of an articulated shaft 211, so that the crossbeam 21 can be rotated through the connection form of the articulated shaft 211 and with it as the rotation center. The connection position of the articulated shaft 211 is not limited to the position under the crossbeam 21. In order to maintain the horizontal state of the crossbeam 21, on the one hand, an angle sensor 25 is added to the crossbeam 21, and on the other hand, a vertical loading component 3 is set on the crossbeam 21. A support plate 34 is set below the end of the crossbeam 21 opposite to the articulated shaft 211, and the support plate 34 is set below the end of the crossbeam 21 opposite to the articulated shaft 211. 4 is provided with a servo motor 31, the output end of the servo motor 31 drives the support seat 36 to slide on the second slide rail 35, and the support seat 36 is connected to the test wheel position 32 through the multi-component force sensor 33. Therefore, the test wheel position 32 can only move vertically up and down along the direction of the second slide rail 35 under the drive of the servo motor 31. The height of the test wheel position 32 is adjusted by the servo motor 31, and high-precision vertical loading is achieved in conjunction with the leveling component 2. The support plate 34 and the crossbeam 21 connected thereto can provide sufficient supporting force for the test wheel position 32, so that the test tire 4 installed thereon can carry a heavier load. Therefore, after the test tire 4 is installed on the test wheel position 32, the test tire 4 is abutted against the ground. At this time, the crossbeam 21 will definitely be in an inclined state because the test tire 4 abuts against the road surface, and the feedback signal of the angle sensor 25 will not be 0°. If the beam 21 is tilted downward, the servo motor 31 is driven to push the test wheel position 32 downward, thereby lifting the beam 21 upward until the beam 21 is horizontal; if the beam 21 is tilted upward, the servo motor 31 is driven to push the test wheel position 32 upward, thereby lowering the beam 21 until the beam 21 is horizontal.

[0048] According to the requirement of loading the vertical load on the test tire 4, the required vertical force is set to Fz, the weight of the weight 24 is set to Mg, the distance between the weight 24 and the hinge shaft 211 is set to L1, and the distance between the test wheel position 32 and the hinge shaft 211 is set to L2. When the weight 24 is not added, the weight Mg of the weight 24 and the distance L2 between the test wheel position 32 and the hinge shaft 211 are fixed values. According to the lever principle, the relationship between Fz, Mg, L1 and L2 meets Therefore, the farther the distance between the weight 24 and the hinge shaft 211 is, the larger the value of Fz will be. In the absence of a driving component 26 to change the position of the loading seat 23, the position of the weight 24 can be calculated, and then the weight 24 can be pulled to change its position on the beam 21, so as to adjust the value of Fz. The weight 24 can also be pulled along the first slide rail 22 by a driving component 26, such as a motor, a reducer, or a gear rack to change its position, so as to adjust the value of Fz. The function of the multi-component force sensor 33 is to collect the value of Fz in order to facilitate the position adjustment of the weight 24.

[0049] It should be noted that in the driving member 26, Figure 6 As shown, it can be realized by a motor, a reducer, a gear rack drive, which belongs to the prior art, and its purpose is to adjust the position of the weight 24 on the beam 21, so how to achieve it will not be described in detail here.

[0050] At this time, the crossbeam 21 is on the horizontal line, and the gravity of the weight 24 acts vertically on the crossbeam 21, ensuring that the additional longitudinal force in the ground reaction force on the tire is zero. When the weight 24 passes forward and is located above the central axis where the test tire 4 is located, this treatment can reduce the total weight of the weight 24. In other words, the maximum vertical load of the test tire 4 is not completely provided by the weight 24, and the dead weight of the crossbeam 21 and the components installed thereon can be used, so that the weight of the whole vehicle is reduced. When the weight of the weight 24 is not enough to change the size of Fz, the size of Mg can be changed by adding weights 24, so that it can be applied to tires of more different specifications and load sizes. When passing the test road surface at a constant speed at a specified speed, the multi-component force sensor installed 33 measures the maximum braking force of the tire from the time when the brake 39 starts emergency braking to the time when the test tire is locked, thereby obtaining data such as the (instantaneous) braking force, (instantaneous) test load, (instantaneous) braking force coefficient, peak braking force, braking peak adhesion coefficient, braking slip adhesion coefficient and slip rate. Compared with the prior art, when facing test tires 4 with different radii, the crossbeam 21 cannot always maintain a horizontal state, so it is always necessary to eliminate the additional longitudinal force by "zeroing" the sensor. The intervention and calibration of more parameters during the test process will result in the final data being unable to be close to the measurement of the actual data. Fundamentally eliminating this additional longitudinal force can avoid excessive data calibration, making the output of the final test data more intuitive and objective.

[0051] Example 2

[0052] The difference between this embodiment and embodiment 1 is that:

[0053] like Fig. 9As shown, the vertical loading assembly 3 also includes a fixed plate 37 and a third slide rail 38. The third slide rail 38 is arranged on the fixed plate 37. The fixed plate 37 is slidably connected to the mounting seat 212 on the beam 21 through the third slide rail 38. The output end of the servo motor 31 is connected to the fixed plate 37. The test wheel position 32 is connected to the fixed plate 37 through the multi-component force sensor 33.

[0054] By slidably connecting the fixing plate 37 in the mounting seat 212 on the crossbeam 21, the servo motor 31 is connected to the fixing plate 37 through its output end, so that it can move the fixing plate 37 up and down during the driving process, thereby driving the test tire 4 on the test wheel position 32 on the fixing plate 37 to move vertically up and down only along the direction of the third slide rail 38. The height of the test wheel position 32 is adjusted by the servo motor 31, and high-precision vertical loading is achieved in conjunction with the leveling component 2. The fixing plate 37 can provide support for the test wheel position 32, so that the test tire 4 installed thereon can carry a heavier load, but the load borne on the fixing plate 37 will be worse than that of the support plate 34 in Example 1, but the good operation of the device can still be guaranteed.

[0055] The beneficial effects of the present invention are as follows: in order to meet the requirements of accurately vertically loading the test tire 4 and ensuring that its longitudinal component is zero, the test wheel position 32 is pushed downward by the servo motor 31, so that the crossbeam 21 installed by the servo motor 31 rotates upward with the hinge shaft 211 as the rotation center under the reverse force, and the vertical position of the test tire 4 is adjusted. In conjunction with the angle sensor 25, the feedback signal of the angle sensor 25 is made to be 0°, ensuring that the crossbeam 21 is on a horizontal line, and the gravity of the weight 24 acts vertically on the crossbeam 21, ensuring that the additional longitudinal force in the ground reaction force received by the test tire 4 is zero. Therefore, there is no need to eliminate the influence of the additional longitudinal force on the measuring sensor by "returning to zero", thereby improving the accuracy of the relative grip performance test of the test tire 4 on a wet road.

[0056] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments may still be modified, or some or all of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A loading device for a trailer for a vehicle tire road test, characterized in that: It includes an axle, a leveling component, a vertical loading component and a test tire. The rotating wheel below the axle abuts against the road surface. The rear part of the leveling component is rotatably connected to the frame above the axle. The vertical loading component is arranged at the front part of the leveling component and is kept vertical to the road surface. The test tire is detachably connected to the bottom of the vertical loading component and abuts against the road surface.

2. The loading device of the automobile tire road test trailer according to claim 1, characterized in that: The leveling assembly includes a crossbeam, a first slide rail, a loading seat and a weight. The crossbeam is rotatably connected to the frame, the first slide rail is laid on the crossbeam, the lower part of the loading seat is slidably connected to the first slide rail, and the weight is detachably mounted on the loading seat.

3. The loading device of the automobile tire road test trailer according to claim 2, characterized in that: The leveling assembly further includes an angle sensor, which is disposed on the crossbeam.

4. The loading device of the automobile tire road test trailer according to claim 3 is characterized in that: The leveling assembly further includes a driving member, which is disposed on the crossbeam. The loading seat slides on the first slide rail under the driving of the driving member.

5. The loading device of the automobile tire road test trailer according to claim 4, characterized in that: The vertical loading assembly is vertically installed on one side of the crossbeam, and the vertical loading assembly includes a servo motor, a test wheel position and a multi-component force sensor. The servo motor is arranged on the crossbeam and connected to the test wheel position through the multi-component force sensor. The test wheel position adjusts the up and down height position under the drive of the servo motor, and the test tire is detachably connected to the test wheel position.

6. The loading device of the automobile tire road test trailer according to claim 5, characterized in that: The vertical loading assembly also includes a support plate, a second slide rail and a support seat, the support plate is connected below the cross beam, the second slide rail is arranged on the support plate, the support seat slides on the second slide rail driven by a servo motor, and the support seat is connected to the test wheel position through a multi-component force sensor.

7. The loading device of the automobile tire road test trailer according to claim 5, characterized in that: The vertical loading assembly also includes a fixed plate and a third slide rail, wherein the third slide rail is arranged on the fixed plate, and the fixed plate is slidably connected to the mounting seat on the beam through the third slide rail. The output end of the servo motor is connected to the fixed plate, and the test wheel position is connected to the fixed plate through a multi-component force sensor.

8. The loading device for the automobile tire road test trailer according to claim 6 or 7, characterized in that: The vertical loading assembly also includes a brake, which is arranged on the test wheel position.

9. A loading test method for a vehicle tire road test trailer according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1: Hang the axle at the rear of the test trailer so that its rotating wheels are in contact with the road surface, install the test tires on the test wheel positions and let the test tires contact with the road surface; S2: Drive the servo motor to adjust the vertical position of the test wheel, and cooperate with the angle sensor to ensure that the beam remains horizontal; S3: Set the vertical force required to load the vertical load on the test tire to Fz, set the weight of the weight to Mg, set the distance between the weight and the articulation axis to L1, set the distance between the test wheel position and the articulation axis to L2, and meet the requirements. Calculate the formula of S4: When the weight Mg and the distance L2 between the test wheel and the articulated axis are fixed values, the driving component is started, and the lateral position of the weight on the beam is adjusted through the driving form of the motor, the reducer, and the gear rack, so as to change the value of L1, and finally change the actual vertical load value collected by the multi-component force sensor until its value reaches the required vertical force Fz; S5: When the test trailer passes the test road surface at a constant speed at a specified speed, the maximum braking force of the tire from the start of emergency braking to the moment when the wheel is locked is measured by a multi-component force sensor.

10. The loading test method of the automobile tire road test trailer according to claim 8, characterized in that: The S4 also includes: weights can be added as needed, so as to change the size of Mg to adapt to the vertical load requirements of different test tires.

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