An excitation loading mechanism for static load modal testing of vehicle tires

Abstract

The application discloses a kind of for vehicle tire static load modal test excitation loading mechanism, including work type base and sample piece fixed pedestal, the top main shaft end of sample piece fixed pedestal is equipped with wheel hub adapter, the back of fixed plate is provided with Z direction stiffness measurement scale, horizontal excitation platform is provided on main loading platform, the bottom end surface central place of horizontal excitation platform is equipped with rolling bearing, the bottom of main loading platform is supported by two groups of air spring, and horizontal excitation platform is fixedly assembled with exciter by the exciter mounting seat of the outside of main loading platform.The method of Z direction static load loading and X, Y, Z direction excitation on static load loading surface to the tire piece to be measured can be realized simultaneously in the application;The structural design of main loading platform and horizontal excitation platform satisfies the demand of structural strength, first-order natural frequency, self-weight light weight, realizes the demand of "loading surface is excitation surface", so that the test result of test rig is closer to the vibration transmission characteristics under actual working condition.

Description

Technical Field

[0001] This invention relates to the field of tire excitation testing, and in particular to an excitation loading mechanism for static load modal testing of vehicle tires. Background Technology

[0002] During vehicle operation, the tires are supported by the ground, and due to the unevenness of the ground, they are also subjected to vibration excitation transmitted from the ground. This excitation is transmitted to the vehicle interior through structures such as tires, rims, and chassis, and is perceived by the occupants in the form of vibration or noise, affecting the driving and riding experience. In order to study this problem, it is necessary to study the vibration transmission characteristics of each subsystem along the vibration transmission path, and tires and rims are a key part of this study.

[0003] To study the vibration transmission characteristics of tire and rim systems, the following engineering methods are used:

[0004] A. Free modal testing: This method involves placing the tire and rim in a free suspension state, selecting specific excitation and measurement points for excitation and measurement, and establishing a modal model of the test component. However, over a long period of time, it was found that the modal characteristics exhibited by the tire and rim system in the free state and under working conditions are significantly different. The results obtained by this method have significant deviations from the study of vibration transmission characteristics under actual working conditions.

[0005] B. Static load constraint modal test; the tire and rim are fixed on a specific bracket, and a vertical static load is applied to the tire surface; this scheme is similar to the scheme in this patent; because the space is occupied by the loading mechanism, the tire loading surface of this scheme cannot be used as an excitation point and test point; while in actual working conditions, the loading surface is also the excitation surface; therefore, the modal model established by this method cannot accurately express the vibration transmission characteristics under actual working conditions.

[0006] Based on the above, this solution improves the B test method, realizing the requirement that "the loading surface is the excitation surface", making the bench test results closer to the vibration transmission characteristics under actual working conditions. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide an excitation loading mechanism for static load modal testing of vehicle tires.

[0008] This invention provides the following technical solution:

[0009] This invention provides an excitation loading mechanism for static load modal testing of vehicle tires, comprising an I-shaped base and a sample fixing base. The sample fixing base is slidably mounted on the top slide rail surface of the I-shaped base via a floor plate module. A hub adapter is installed at the top spindle end of the sample fixing base. A linear slide rail is mounted on the outer side of the sample fixing base via a fixing plate. A Z-axis stiffness measuring scale is provided on the back of the fixing plate. A main loading platform is slidably mounted on the outer surface of the linear slide rail via a slider. A threaded hole is provided on the main loading platform. A horizontal excitation platform is provided on the main loading platform. A rolling bearing is installed at the center of the bottom end face of the horizontal excitation platform. The bottom of the main loading platform is supported by two sets of air springs. A vibrator is fixedly mounted on the outer side of the main loading platform via a vibrator mounting seat.

[0010] As a preferred embodiment of the present invention, the air spring is supplied with compressed gas via an external air pump, enabling the main loading platform to move up and down via a linear slide rail, thereby adjusting the distance between the main loading platform and the horizontal excitation platform.

[0011] As a preferred embodiment of the present invention, the excitation rod end of the vibrator is connected to the rolling bearing end of the bottom surface of the horizontal excitation platform, and the vibrator is disposed on the X-direction outer side or Y-direction outer side of the main loading platform.

[0012] As a preferred embodiment of the present invention, a dynamic force sensor can be connected in series between the top spindle end of the sample fixing base and the hub adapter.

[0013] As a preferred embodiment of the present invention, the main loading platform and the horizontal excitation platform are made of magnesium alloy or titanium alloy. The bottom surface of the main loading platform is provided with ribs and weight reduction holes to enhance its structural rigidity. The bottom surface of the horizontal excitation platform is provided with a number of intersecting ribs to enhance its structural rigidity.

[0014] As a preferred embodiment of the present invention, the upper surface of the horizontal excitation platform is frosted, knurled, or has friction pads with different coefficients of friction attached.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] This invention enables simultaneous static loading of the tested tire component in the Z direction and excitation in the X, Y, and Z directions on the static loading surface. The structural design of the main loading platform and the horizontal excitation platform ensures that the main loading platform simultaneously meets the requirements of structural strength, first-order natural frequency, and lightweight design, realizing the requirement that "the loading surface is the excitation surface," and making the bench test results closer to the vibration transmission characteristics under actual working conditions. Attached Figure Description

[0017] 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:

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0019] Figure 2 This is a schematic diagram of the main loading platform of the present invention;

[0020] Figure 3 This is a schematic diagram of the horizontal excitation platform of the present invention;

[0021] Figure 4 This is a schematic diagram of the exciter structure of the present invention;

[0022] Figure 5 This is a schematic diagram of the Z-axis stiffness measurement scale of the present invention;

[0023] Figure 6 This is a diagram showing the state of the wheel hub adapter assembled at the end of the sample fixing base in this invention;

[0024] Figure 7 This is a bottom view of the horizontal excitation platform in this invention;

[0025] Figure 8 This is a schematic diagram of an embodiment of the present invention during X-axis modal testing;

[0026] Figure 9 This is a schematic diagram of an embodiment of the present invention during Y-axis modal testing;

[0027] Figure 10 This is a schematic diagram of an embodiment of the present invention during Z-axis modal testing;

[0028] In the diagram: 1. I-shaped base; 2. Sample fixing base; 3. Iron floor module; 4. Hub adapter; 5. Linear slide rail; 6. Z-axis stiffness measuring scale; 7. Main loading platform; 8. Horizontal excitation platform; 9. Rolling bearing; 10. Air spring; 11. Vibrator mounting base; 12. Vibrator;

[0029] 71. Threaded hole. Detailed Implementation

[0030] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention. All identical reference numerals in the drawings refer to the same components.

[0031] Furthermore, detailed descriptions of known technologies are omitted if they are unnecessary to illustrate the features of the present invention. It should be noted that the terms "front," "rear," "left," "right," "up," and "down" used in the following description refer to directions in the accompanying drawings, while the terms "inner" and "outer" refer to directions toward or away from the geometric center of a particular component, respectively.

[0032] Example 1

[0033] like Figure 1-10 This invention provides an excitation loading mechanism for static load modal testing of vehicle tires, including an I-shaped base 1 and a sample fixing base 2. The sample fixing base 2 is slidably mounted on the top slide rail surface of the I-shaped base 1 via a floor module 3. A hub adapter 4 is installed at the top spindle end of the sample fixing base 2. A linear slide rail 5 is installed on the outer side of the sample fixing base 2 via a fixing plate. A Z-axis stiffness measuring scale 6 is provided on the back of the fixing plate. A main loading platform 7 is slidably mounted on the outer side of the linear slide rail 5 via a slider. A threaded hole 71 is provided on the main loading platform 7. A horizontal excitation platform 8 is provided on the main loading platform 71. A rolling bearing 9 is installed at the center of the bottom end face of the horizontal excitation platform 8. The bottom of the main loading platform 7 is supported by two sets of air springs 10. An exciter 12 is fixedly mounted on the outer side of the main loading platform 7 via an exciter mounting seat 11.

[0034] The air spring 10 is filled with compressed gas by an external air pump, which enables the main loading platform 7 to move up and down via the linear slide rail 5, thereby adjusting the distance between the main loading platform 7 and the horizontal excitation platform 8.

[0035] The excitation rod end of the vibrator 12 is connected to the end of the rolling bearing 9 on the bottom surface of the horizontal excitation platform 8. The vibrator 12 is located on the X-direction outer side or Y-direction outer side of the main loading platform 7.

[0036] A dynamic force sensor can be connected in series between the top spindle end of the sample fixing base 2 and the hub adapter 4.

[0037] The main loading platform 7 and the horizontal excitation platform 8 are made of magnesium alloy or titanium alloy. The bottom surface of the main loading platform 7 is provided with ribs and weight reduction holes to enhance its structural rigidity. The bottom surface of the horizontal excitation platform 8 is provided with several intersecting ribs to enhance its structural rigidity.

[0038] Furthermore, the working principle of this device is as follows:

[0039] Install the tire sample onto the top shaft of the sample fixing base 2, such as Figure 6 As shown, the main loading platform 7 has the following functions:

[0040] (1) Transmit the static load applied upward by the air spring to the tire sample under test, including X, Y, and Z direction excitation tests and stiffness tests;

[0041] (2) When performing vertical (Z-axis) excitation tests, the exciter is connected to the bottom, and the vibration is directly transmitted through the platform 7 without the need for horizontal excitation platform 8 to transmit it to the tire sample under test;

[0042] The vibrator 12 is a general-purpose standard experimental device;

[0043] Its function is to output vibration excitation to the outside;

[0044] When performing X and Y direction vibration tests, the vibrator 12 is connected to the horizontal excitation platform 8 through the excitation rod, so that the vibration excitation is transmitted to the tire part under test.

[0045] When performing Z-axis vibration test, the exciter 12 is connected to the main loading platform 7 through the excitation rod, so that the vibration excitation is transmitted to the tire under test.

[0046] The specific working principle is as follows:

[0047] Its main loading platform 7 is driven by air spring 10, without the need for other external driving equipment. When static load is applied, air spring 10 is inflated, and the height of air spring 10 increases accordingly, driving the main loading platform 7 to rise. After contacting the surface of the tire of the test piece, the tire gradually deforms under the force. When the loading requirement is reached, the air spring 10 is stopped from being inflated, and the upward force of air spring 10 and the downward force of tire are balanced.

[0048] A dynamic force sensor can be connected in series between the hub adapter 4 and the sample fixing base 2 to measure the wheel center force. Various models of dynamic force sensors are available, and their testing principle is as follows: 3-4 three-dimensional force sensor units (LC) are arranged between the base plate and the top plate, with each sensor unit positioned on the same pitch circle; (the base plate is fixed to the flange face of the sample fixing base, and the top plate is fixed to the wheel rim of the test piece (or the wheel rim adapter 4); each sensor unit outputs forces in three directions (Fxi, Fyi, Fzi); by collecting the outputs of all sensor units and performing specific calculations, the loads in six directions on the wheel center of the test piece can be obtained (forces: Fx, Fy, Fz; torques: Mx, My, Mz).

[0049] The main loading platform 7 and the horizontal excitation platform 8 need to transmit the vibration excitation of the exciter 12 to the test piece, and their own weight has a direct impact on the experimental performance. Simply put, the greater their mass, the more vibration energy they consume, and the less vibration energy is applied to the test piece. Therefore, their own weight must be controlled.

[0050] Meanwhile, the main loading platform 7 and the horizontal excitation platform 8 are in direct contact with the device under test, and their own natural frequencies need to avoid the frequency range of the device under test that is of interest to the test. Here, it needs to be greater than 250Hz.

[0051] Based on the above two points, the materials of the main loading platform 7 and the horizontal excitation platform 8 need to simultaneously meet the requirements of low density and high hardness, with magnesium alloy and titanium alloy considered as backup materials; in terms of structure, their rigidity is enhanced by arranging ribs and stiffeners, and their weight is optimized by arranging weight-reducing holes, such as... Figure 2 and Figure 7 As shown;

[0052] The upper surface of the horizontal excitation platform 8 undergoes special treatment to control its friction coefficient, ensuring that more of the excitation energy output by the vibrator 12 is transferred to the tire being tested. This treatment includes the following three methods:

[0053] 1. The horizontal excitation platform 8 is sandblasted and then hard anodized. This solution is simple and easy to implement, but the coefficient of friction is not high, and it is suitable for tires with softer materials.

[0054] 2. Horizontal excitation platform 8 surface knurling followed by hard anodizing;

[0055] 3. Friction pads of different mesh sizes (coefficient of friction) are glued to the surface of the horizontal excitation platform 8. The advantage is that different friction pads can be replaced according to needs, but the disadvantage is that they are prone to wear after long-term use. This solution recommends using the third method.

[0056] Under the constraint of the linear slide rail 5, the main loading platform 7 can move in the Z direction; driven by the two sets of air springs 10 below, it applies static load to the tire being tested.

[0057] X-axis modal testing (e.g.) Figure 8 As shown, the horizontal excitation platform 8 is arranged along the X direction. After the static load is completed, the exciter 12 is arranged in the "X direction excitation" position, and the excitation rod of the exciter 12 is connected and locked with a nut. The horizontal excitation platform 8 transmits the excitation to the tire surface of the test piece under the drive of the exciter 12. At the same time, the static load on the test piece in the Z direction and the excitation in the X direction on the static load surface are realized.

[0058] Y-direction modal testing (e.g.) Figure 9 As shown), the horizontal excitation platform 8 is arranged along the Y direction. After the static load is completed, the exciter 12 is arranged in the "Y direction excitation". The installation of the excitation rod of the exciter 12 is the same as that of the X direction application. The horizontal excitation platform 8 transmits the excitation to the tire surface of the test piece under the drive of the exciter 12. At the same time, the static load on the test piece in the Z direction and the excitation in the Y direction on the static load surface are realized.

[0059] During Z-axis modal testing (e.g.) Figure 10As shown), without using the horizontal excitation platform 8, the vibrator 12 is arranged in the "Z-direction excitation" configuration (placed below the main loading platform 7). The thread of the excitation rod end of the vibrator 12 is screwed into the threaded hole in the middle of the lower surface of the main loading platform 7 and locked with a nut. The main loading platform 7 transmits the excitation to the tire surface of the test piece under the drive of the vibrator 12. At the same time, the Z-direction static load on the test piece and the Z-direction excitation on the static load surface are realized.

[0060] Z-axis stiffness test (e.g.) Figure 10 as well as Figure 5 As shown), a Z-axis stiffness measuring scale 6 is set on one side of the back of the fixing plate on the outer side of the sample fixing base 2. The Z-axis stiffness measuring scale 6 has a pointer on its side, which makes it easy to point to the Z-axis stiffness measuring scale 6 for reading. The horizontal excitation platform 8 and the vibrator 12 are not used. The static load force of the tire under test is adjusted to a specific value, and the reading of the Z-axis stiffness measuring scale 6 is read at the same time. A series of such static load forces and scale readings are recorded, and the stiffness characteristics of the test part are calculated.

[0061] For example, when the force sensor outputs F1=250N, the reading on the Z-axis stiffness measuring scale 6 is H1=50mm. If the load on the workpiece continues and the force sensor outputs F2=1000N again, the reading on the Z-axis stiffness measuring scale 6 is H2=75mm. Therefore, the stiffness of the workpiece is: D=(F2-F1) / (H2-H1)=(1000-250) / (75-50)=30N / mm=3*10 4 N / m;

[0062] The following table summarizes the roles of the main loading platform and the level incentive platform in different test applications:

[0063] X-direction excitation test Y-direction stimulus test Z-direction excitation test Stiffness test Main loading platform 1. Static load loading 1. Static load loading 1. Static load application; 2. Vibration excitation; 1. Static load loading Horizontal incentive platform X-axis vibration excitation Y-axis vibration excitation Do not use Do not use vibrator Connects to a horizontal excitation platform to output vibration excitation. Connects to a horizontal excitation platform to output vibration excitation. Connects to the main loading platform and outputs vibration excitation. Do not use

[0064] This invention enables simultaneous static loading of the tested tire component in the Z direction and excitation in the X, Y, and Z directions on the static loading surface. The structural design of the main loading platform 7 and the horizontal excitation platform 8 ensures that the main loading platform 7 simultaneously meets the requirements of structural strength, first-order natural frequency, and lightweight design, realizing the requirement that "the loading surface is the excitation surface," and making the bench test results closer to the vibration transmission characteristics under actual working conditions.

[0065] Finally, it should be noted that the above descriptions 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. An excitation loading mechanism for static load modal testing of vehicle tires, comprising an I-shaped base (1) and a sample fixing base (2), characterized in that, The sample fixing base (2) is slidably installed on the top slide rail surface of the I-shaped base (1) via the iron floor module (3). A hub adapter (4) is installed on the top spindle end of the sample fixing base (2). A linear slide rail (5) is installed on the outside of the sample fixing base (2) via a fixing plate. A Z-axis stiffness measuring scale (6) is provided on the back of the fixing plate. A main loading platform (7) is slidably installed on the outer side of the linear slide rail (5) via a slider. A threaded hole (71) is provided on the main loading platform (7). A horizontal excitation platform (8) is provided on the main loading platform (7). A rolling bearing (9) is installed at the center of the bottom end face of the horizontal excitation platform (8). The bottom of the main loading platform (7) is supported by two sets of air springs (10). An exciter (12) is fixedly assembled on the outside of the main loading platform (7) via an exciter mounting seat (11).

2. The excitation loading mechanism for static load modal testing of vehicle tires according to claim 1, characterized in that, The excitation rod end of the exciter (12) is connected to the end of the rolling bearing (9) on the bottom surface of the horizontal excitation platform (8), and the exciter (12) is located on the X-direction outer side or Y-direction outer side of the main loading platform (7).

3. The excitation loading mechanism for static load modal testing of vehicle tires according to claim 1, characterized in that, A dynamic force sensor can be connected in series between the top spindle end of the sample fixing base (2) and the hub adapter (4).

4. The excitation loading mechanism for static load modal testing of vehicle tires according to claim 1, characterized in that, The main loading platform (7) and the horizontal excitation platform (8) are made of magnesium alloy or titanium alloy. The bottom surface of the main loading platform (7) is provided with ribs and weight reduction holes to enhance its structural rigidity. The bottom surface of the horizontal excitation platform (8) is provided with several intersecting ribs to enhance its structural rigidity.

5. The excitation loading mechanism for static load modal testing of vehicle tires according to claim 1, characterized in that, The upper surface of the horizontal excitation platform (8) is frosted, knurled, or has friction pads with different coefficients of friction attached.

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