Suspension bushing test method and test tool

Abstract

The invention relates to the technical field of automobile accessories, in particular to a suspension bushing testing method and tool, and the method comprises the steps: obtaining the static reaction force Fnmj borne by a suspension bushing according to different working conditions of an automobile; according to the static bearing reaction Fnmj, bidirectional dynamic stiffness testing equipment applies bidirectional loads in the first direction, the second direction and the third direction to the suspension bushing, and the first direction, the second direction and the third direction are perpendicular to one another; acquiring mechanical performance data of the suspension bushing under each of the bidirectional loads; and calculating the dynamic stiffness parameter kndmj of the suspension bushing according to the mechanical performance data. According to the technical scheme, the dynamic stiffness parameter of the suspension bushing is obtained, and therefore reference data are provided for whole vehicle NVH performance design.

Description

Technical Field

[0001] The invention relates to the technical field of auto parts and automobiles, and in particular to a suspension bushing testing method and a testing tool. Background Art

[0002] NVH performance, namely noise, vibration and harshness performance, is an important indicator to measure the comfort and quality of automobiles. It covers all the noise and vibration generated by the vehicle during operation and the discomfort caused to the driver and passengers. Good NVH performance can provide a more comfortable and quiet riding environment for the driver and passengers, while reducing fatigue damage to vehicle components and increasing the overall service life of the vehicle.

[0003] The dynamic stiffness parameters of the suspension bushing play a vital role in NVH performance. Dynamic stiffness refers to the stiffness characteristics of the bushing under dynamic load, which directly affects the transmission and attenuation of the suspension system to engine vibration and road impact. A suitable dynamic stiffness parameter can effectively isolate the vibration between the engine and the body, reduce the noise inside the car, and improve ride comfort. On the contrary, if the dynamic stiffness parameters do not match, it may lead to aggravated NVH problems and affect the overall performance of the vehicle.

[0004] In the related technology, the traditional dynamic stiffness test methods have some shortcomings. First, these methods often use unidirectional preload, which cannot fully reflect the multi-directional stress state of the bushing in actual work. Secondly, the correspondence between the preload size and the actual vehicle working conditions is not strong, resulting in a large difference between the test results and the actual application. Furthermore, the magnitude of the excitation amplitude is not strongly corresponding to the vibration magnitude of the suspension under the actual vehicle working conditions, which makes the dynamic stiffness parameters of the bushing obtained from the test have weak reference value when applied to the NVH performance design of the whole vehicle. These problems limit the application value of traditional dynamic stiffness test methods in optimizing automotive NVH performance. Summary of the invention

[0005] The main purpose of the present invention is to propose a suspension bushing test method, which aims to obtain the dynamic stiffness parameters of the suspension bushing, thereby providing reference data for the NVH performance design of the whole vehicle.

[0006] To achieve the above object, the suspension bushing test method proposed in the present invention comprises: According to different working conditions of the car, the static support reaction force F of the suspension bushing is obtained. n mj ; According to the static support reaction force F n mj, a two-way dynamic stiffness test device applies a bidirectional load in a first direction, a second direction and a third direction to the suspension bushing, wherein the first direction, the second direction and the third direction are perpendicular to each other; Acquiring mechanical performance data of the suspension bushing under each of the bidirectional loads; According to the mechanical performance data, the dynamic stiffness parameter k of the suspension bushing is calculated. n dmj .

[0007] In one embodiment of the present invention, before the step of obtaining the mechanical performance data of the suspension bushing under each of the bidirectional loads, the step further includes: Fixing the suspension bushing on a test fixture, wherein the test fixture is connected to a two-way dynamic stiffness test device; The two-way dynamic stiffness testing device is driven to apply the two-way loads in the first direction, the second direction and the third direction to the testing fixture.

[0008] In one embodiment of the present invention, the static support reaction force on the suspension bushing is obtained according to different working conditions of the automobile, including: According to different working conditions of the car, different wheel torque T of the car is obtained. n w ; According to the wheel side moment T n w , the static support reaction force F of the suspension bushing in the first direction, the second direction and the third direction is obtained n mj .

[0009] In one embodiment of the present invention, the wheel side moment T n w , the static support reaction force F of the suspension bushing in the first direction, the second direction and the third direction is obtained n mj ,include: According to the wheel side moment T n w , the powertrain gravity is applied at the center of mass of the vehicle powertrain and the wheel torque T is applied at the axis of the engine crankshaft n w ; When the suspension bushing reaches static equilibrium, the static support reaction force F of the suspension bushing in the first direction, the second direction and the third direction is calculated. n mj .

[0010] In one embodiment of the present invention, different wheel side torques T of the vehicle are obtained according to different working conditions of the vehicle. n w ,include: According to different working conditions of the car, the output torque T of the car engine under each working condition is obtained. n e , the speed ratio of the transmission n t , speed ratio of the main reducer i n r And the transmission efficiency η of the automobile transmission system n ; According to the calculation formula, different wheel torques T of the car are obtained. n w .

[0011] In one embodiment of the present invention, the suspension bushing is fixed to a test fixture, and the test fixture is connected to a two-way dynamic stiffness test device, comprising: The two connecting surfaces of the suspension bushing along the first direction, the second direction and the third direction are respectively fixed to two matching fixing surfaces on the test fixture, and the back surfaces of any two fixing surfaces in each direction are respectively connected to the two-way dynamic stiffness test equipment.

[0012] In one embodiment of the present invention, before the step of fixing the suspension bushing on the test fixture and connecting the test fixture to the two-way dynamic stiffness test equipment, the step further includes: Designing the test fixture according to the dynamic stiffness simulation experiment of the suspension bushing; A constrained modal analysis is performed on the test fixture with boundary states.

[0013] In an embodiment of the present invention, the mechanical performance data includes actual dynamic force, actual amplitude and phase angle of the suspension bushing.

[0014] In one embodiment of the present invention, the step of controlling the two-way dynamic stiffness testing device to apply a bidirectional load in the first direction, the second direction and the third direction to the testing fixture comprises: Controlling the two-way dynamic stiffness testing device to apply a swept frequency excitation of a first frequency and a second frequency to the testing fixture; The bidirectional load on the suspension bushing under each frequency sweep excitation is obtained, and the two-way dynamic stiffness test equipment is controlled to apply bidirectional loads in the first direction, the second direction and the third direction to the test fixture.

[0015] The present invention further provides a test fixture, comprising an upper fixture and a lower fixture; the upper fixture comprises first fixing surfaces along a first direction, a second direction and a third direction respectively, the lower fixture comprises a second fixing surface adapted to the first fixing surface along each direction, and any two opposite first fixing surfaces and second fixing surfaces can be connected to the connection surface of the suspension bushing; Among them, the back side of any one of the first fixing surfaces of the upper clamp is configured to be connected to the upper support of the two-way dynamic stiffness testing device, and the back side of any one of the second fixing surfaces of the lower clamp is configured to be connected to the lower support of the two-way dynamic stiffness testing device.

[0016] In the technical solution of the present invention, by simulating the static support reaction force and dynamic load under typical working conditions of the NVH performance of the whole vehicle, the test method can test the dynamic stiffness parameters of the suspension bushing with high precision, which helps to more accurately evaluate the performance of the bushing under actual use conditions. Moreover, unlike the traditional unidirectional preload test method, this solution can achieve multi-directional preload and more comprehensively simulate the actual working conditions, thereby providing more accurate test results; further, accurate dynamic stiffness parameters are crucial to optimizing the NVH performance of the whole vehicle, and this technical solution helps to improve the ride comfort and handling stability of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] 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 the structures shown in these drawings without paying creative work.

[0018] Figure 1 A schematic flow chart of a suspension bushing testing method provided by the present invention; Figure 2 A flowchart of step S210 in an embodiment of the suspension bushing testing method provided by the present invention; Figure 3 A flowchart of step S2110 in an embodiment of the suspension bushing testing method provided by the present invention; Figure 4 A flowchart of step S2120 in an embodiment of the suspension bushing testing method provided by the present invention; Figure 5 A flowchart of step S400 in an embodiment of the suspension bushing testing method provided by the present invention; Figure 6 A schematic overall flow chart of the suspension bushing testing method provided by the present invention; Figure 7A test assembly diagram of the test tool provided by the present invention in a first direction; Figure 8 A test assembly diagram of the test tool provided by the present invention in a second direction; Fig. 9 A test assembly diagram of the test tool provided by the present invention in a third direction; Fig.10 A suspension bushing dynamic stiffness test data diagram obtained by the suspension bushing test method provided by the present invention; Fig.11 This is a model test diagram of the suspension bushing test method provided by the present invention.

[0019] Description of Figure Numbers: 10. upper fixture; 20. lower fixture; 11. first fixing surface; 21. second fixing surface; The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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 are within the scope of protection of the present invention.

[0021] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0022] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0023] The suspension bushing test method proposed by the present invention comprises: Step S210: Obtain the static support reaction force F of the suspension bushing according to different working conditions of the vehicle n mj ; Step S220: According to the static support reaction force F n mj , a two-way dynamic stiffness test device applies a bidirectional load in a first direction, a second direction and a third direction to the suspension bushing, wherein the first direction, the second direction and the third direction are perpendicular to each other; Step S500: obtaining mechanical performance data of the suspension bushing under each of the bidirectional loads; Step S600: Calculate the dynamic stiffness parameter k of the suspension bushing according to the mechanical performance data n dmj .

[0024] Explanation of step S210: Different working conditions of automobiles include working conditions of traditional fuel vehicles and working conditions of new energy vehicles. For traditional fuel vehicles, typical working conditions of the whole vehicle NVH performance include: N gear idling working condition, R gear idling working condition, D1 gear slow acceleration working condition (1POT) and 3 gear full throttle acceleration working condition (3WOT); for new energy vehicles, typical working conditions of the whole vehicle NVH performance include: idling charging (including feeding charging) working condition, D gear slow acceleration working condition (POT), and D gear full throttle acceleration working condition (WOT); based on this, the static support reaction force F of the suspension bushing of the automobile under different working conditions is obtained. n mj , such as the left suspension bushing and the right suspension bushing, how to obtain the static support reaction force F n mj , which will be explained later. Among them, the static support reaction force F of the suspension bushing under each working condition is n mj , including the static support reaction force F in the U, V and W directions n mj , where U, V, and W correspond to the three coordinate axis directions of the Y, X, and Z axes of the three-dimensional Cartesian coordinate system, respectively. Based on the installation position and force conditions of the suspension bushing in the automobile assembly, the static support reaction force F of the suspension bushing in the U, V, and W directions is n mj Both are bidirectional loads with two acting directions in opposite directions.

[0025] Step S220: According to the static support reaction force F n mjThe two-way dynamic stiffness test equipment applies a bidirectional load in a first direction, a second direction and a third direction to the suspension bushing, wherein the first direction, the second direction and the third direction are perpendicular to each other, wherein the bidirectional load applied by the two-way dynamic stiffness test equipment to the suspension bushing is the static support reaction force F received by the suspension bushing under different vehicle working conditions. n mj The two-way dynamic stiffness test equipment needs to perform mechanical tests on the suspension bushing three times in different directions in sequence. The first direction, the second direction and the third direction correspond to the U direction, the V direction and the W direction respectively, so as to simulate the stress conditions of the suspension bushing under different working conditions of the automobile. By testing and evaluating the suspension bushing in multiple directions using the dynamic stiffness two-way dynamic stiffness test equipment, the comprehensive mechanical performance of the suspension bushing can be obtained, which is convenient for optimizing the NVH performance of the automobile.

[0026] Step S500: Acquire the mechanical performance data of the suspension bushing under each of the bidirectional loads, wherein the relevant data is recorded by using a sensor, an industrial camera or other device, and the mechanical performance data is the test result of the suspension bushing in each direction, including the actual dynamic force, actual amplitude and phase angle of the suspension bushing. In one embodiment, the actual dynamic force (F 3WOT 左U 、F 3WOT 左V 、F 3WOT 左W 、F 2POT 左U 、F 2POT 左V 、F 2POT 左W ), actual amplitude (S 3WOT 左U , S 3WOT 左V , S 3WOT 左W , S 2POT 左U , S 2POT 左V , S 2POT 左W ) and the phase angle (θ 3WOT 左U ,θ 3WOT 左V ,θ 3WOT 左W ,θ 2POT 左U ,θ 2POT 左V ,θ 2POT 左W ).

[0027] Step S600: Calculate the dynamic stiffness parameter (k n dmj , unit: N / mm), and the dynamic damping coefficient (ζ n dmj , unit: -), dynamic stiffness parameter k n dmj Based on the actual dynamic force of the suspension bushing (F n dmj , unit: N), actual amplitude (S n dmj , unit: mm) and phase angle (θ n dmj , unit: degree), the specific calculation formula is as follows: , where k n d1mj , k n d2mj are storage stiffness and loss stiffness respectively. Dynamic stiffness and dynamic damping coefficient can be expressed as:

[0028]

[0029] In the technical solution of the present invention, by simulating the static support reaction force and dynamic load under typical working conditions of the NVH performance of the whole vehicle, the test method can test the dynamic stiffness parameters of the suspension bushing with high precision, which helps to more accurately evaluate the performance of the bushing under actual use conditions. Moreover, unlike the traditional unidirectional preload test method, this solution can achieve multi-directional preload and more comprehensively simulate the actual working conditions, thereby providing more accurate test results and enriching the test theory of the suspension bushing stiffness; further, accurate dynamic stiffness parameters are crucial to optimizing the NVH performance of the whole vehicle, and this technical solution helps to improve the ride comfort and handling stability of the vehicle.

[0030] In one embodiment of the present invention, before step S500, the method further includes: Step S300: fixing the suspension bushing on a test fixture, wherein the test fixture is connected to a two-way dynamic stiffness test device; Step S400: driving the two-way dynamic stiffness testing device to apply the two-way loads in the first direction, the second direction and the third direction to the testing fixture.

[0031] For step S300, first, a special test fixture needs to be prepared. The fixture is designed to simulate the actual installation position and stress conditions of the suspension bushing on the car, that is, the test fixture includes an inner side connected to the suspension bushing and an outer side connected to a two-way dynamic stiffness test device, so that the two-way dynamic stiffness test device applies a bidirectional load to the test fixture, and the action of the bidirectional load is transmitted to the suspension bushing to be tested, thereby obtaining the required mechanical performance data.

[0032] For step S400, during the test, the two-way dynamic stiffness test equipment is used to apply the two-way loads in the first direction, the second direction and the third direction to the test fixture. During this process, the suspension bushing needs to replace the connection surface multiple times. Specifically, when testing the dynamic stiffness of the suspension bushing in the U direction, the installation method of the test fixture is as follows. Figure 7 , given in the U and W directions Fig.10 In the corresponding preload, at this time, a first load is applied to the test fixture in the U direction, and a second load is applied to the test fixture in the W direction. Specifically, the two test bench supports of the two-way dynamic stiffness test equipment slowly apply the first load along the U direction to an equivalent static support reaction force, and the two test bench supports stop moving in the U direction. Then, the two-way dynamic stiffness test equipment drives the test bench supports to move in the W direction, thereby obtaining a second load along the W direction to an equivalent static support reaction force, thereby obtaining the dynamic stiffness parameters of the suspension bushing in the U direction; When testing the V-direction dynamic stiffness of the suspension bushing, please refer to the installation method of the test fixture. Figure 8 , given in the V direction Fig.10 In the corresponding preload, at this time, a first load is applied to the test fixture in the V direction, and a second load is applied to the test fixture in the W direction. Specifically, the two test bench supports of the two-way dynamic stiffness test equipment slowly apply the first load along the V direction to the equivalent static support reaction force, and the two test bench supports stop moving in the V direction. Then, the two-way dynamic stiffness test equipment drives the test bench supports to move in the W direction, thereby obtaining the second load along the W direction to the equivalent static support reaction force, thereby obtaining the dynamic stiffness parameters of the suspension bushing in the V direction; When testing the W-direction dynamic stiffness of the suspension bushing, please refer to the installation method of the test fixture. Fig. 9 , given in the W direction Fig.10 In the corresponding preload, at this time, a first load is applied to the test fixture in the W direction, and a second load is applied to the test fixture in the U direction. Specifically, the two test bench supports of the two-way dynamic stiffness test equipment slowly apply the first load along the W direction to the equivalent static support reaction force, and the two test bench supports stop moving in the W direction. Then, the two-way dynamic stiffness test equipment drives the test bench supports to move in the U direction, thereby obtaining the second load along the U direction to the equivalent static support reaction force, thereby obtaining the dynamic stiffness parameters of the suspension bushing in the W direction; in, Fig.10The data in the figure are obtained by simulating two operating conditions: full throttle acceleration in 3rd gear and slow throttle acceleration in 2nd gear. The specific method is explained below.

[0033] In one embodiment of the present invention, step S210 includes: Step S2110: Obtain different wheel torques T of the vehicle according to different working conditions of the vehicle n w ; Step S2120: According to each wheel side moment T n w , the static support reaction force F of the suspension bushing in the first direction, the second direction and the third direction is obtained n mj .

[0034] It needs to be explained that the static support reaction force F n mj It refers to the static load borne by the elastic center of the suspension under the typical working conditions of the vehicle NVH performance. To further explain, the output torque of the powertrain will be transmitted to the vehicle body through the suspension, thereby generating a force on the suspension. The wheel torque is the torque generated after the output torque of the powertrain is transmitted to the drive wheel through the transmission system. It directly reflects the traction or braking force of the powertrain on the vehicle body. Therefore, the wheel torque T under different working conditions of the vehicle is input through Adams or Matlab. n w Adams or Matlab further analyzes and obtains the static support reaction force F of the suspension bushing in the first direction, the second direction and the third direction. n mj。

[0035] In one embodiment of the present invention, step S2120 includes: Step S2121: According to each wheel side moment T n w , the powertrain gravity is applied at the center of mass of the vehicle powertrain and the wheel torque T is applied at the axis of the engine crankshaft n w ; Step S2122: When the suspension bushing reaches static equilibrium, the static support reaction force F of the suspension bushing in the first direction, the second direction and the third direction is calculated. n mj .

[0036] What needs to be explained about step S2121 is that applying the powertrain gravity at the powertrain mass center can simulate the effect of the powertrain weight on the suspension, reflecting the influence of the powertrain mass on the suspension; applying the wheel torque T at the engine crankshaft axisnw , can simulate the effect of the torque output by the engine on the suspension, reflecting the influence of the torque output by the powertrain on the suspension; the force of the powertrain on the suspension can be decomposed into two components, one pointing to the direction of the suspension along the center of gravity of the powertrain, and the other pointing to the direction of the suspension along the axis of the engine crankshaft. Therefore, the powertrain gravity is applied at the center of mass of the powertrain and the wheel torque T is applied at the axis of the engine crankshaft. nw , can more accurately simulate the effect of the powertrain on the suspension. In one example, the weight of the assembly is 2075N, so the wheel torque T is obtained when accelerating at full throttle in 3rd gear. nw The wheel torque T is 1793Nm when accelerating with slow throttle in 2nd gear nw How to obtain the wheel torque T of the car under different working conditions through the assembly gravity? nw , which will be explained later.

[0037] What needs to be explained about step S2122 is that based on obtaining different wheel side moments T n w Then, slowly apply the powertrain gravity (2075N) at the powertrain center of mass and the wheel torque T at the engine crankshaft axis. nw (The torque is 1793Nm when accelerating at full throttle in 3rd gear, and 1250Nm when accelerating at slow throttle in 2nd gear). When static equilibrium is reached, the static support reaction force at the elastic center of the suspension bushing is calculated, and the static support reaction force is decomposed into each translational direction of the left suspension. The static support reaction force obtained is the output value of the two-way dynamic stiffness test equipment.

[0038] In one embodiment of the present invention, step S2110 includes: Step S2111: According to different working conditions of the vehicle, the output torque T of the vehicle engine under each working condition is obtained. n e , the speed ratio of the transmission n t , speed ratio of the main reducer i n r And the transmission efficiency η of the automobile transmission system n ; Step S2112: According to the calculation formula, different wheel side torques T of the vehicle are obtained. n w .

[0039] It is understandable that the car has a fixed output torque T of the car engine in each driving condition. n e , the speed ratio of the transmission n t , speed ratio of the main reducer i n rAnd the transmission efficiency η of the automobile transmission system n Specifically, for the vehicle's 3rd gear full throttle acceleration condition, at this time, the output torque T 3 e The speed ratio of the transmission is 280Nm. 3 t 1.59, main reducer i 3 r The speed ratio is 4.24, and the torque transmission efficiency η3 is 95%; for the 2nd gear slow throttle acceleration condition, at this time, the output torque T 2 e The speed ratio of the transmission is 130Nm. 2 t 2.82, main reducer i 2 r The speed ratio is 3.79 and the torque transmission efficiency η2 is 90%. The following calculation formula is used to obtain: ; , Based on the above output wheel torque T n w , we can get the static support reaction force F of the suspension bushing in the U, V, and W directions n mj , as shown in the table:

[0040] In one embodiment of the present invention, the suspension bushing is fixed to a test fixture, and the test fixture is connected to a two-way dynamic stiffness test device, comprising: The two connecting surfaces of the suspension bushing along the first direction, the second direction and the third direction are fixed to the two fixing surfaces adapted on the test fixture respectively, and the backs of any two fixing surfaces in each direction are connected to the two-way dynamic stiffness test equipment respectively. Specifically, when testing the dynamic stiffness of the suspension bushing in the U direction, the installation method of the test fixture is as follows: Figure 7 , the suspension bushing is vertically connected to two fixed surfaces on the test fixture along the height direction; When testing the V-direction dynamic stiffness of the suspension bushing, please refer to the installation method of the test fixture. Figure 8 , the suspension bushing is vertically connected to two fixed surfaces on the test fixture along the width direction; When testing the W-direction dynamic stiffness of the suspension bushing, please refer to the installation method of the test fixture. Fig. 9 The suspension bushing is horizontally connected to the two fixed surfaces on the test fixture along the length direction. The design method of the test fixture is explained below.

[0041] In one embodiment of the present invention, before step S300, the method further includes: Step S110: designing the test tooling according to the dynamic stiffness simulation experiment of the suspension bushing; Step S120: performing constrained modal analysis on the test fixture in a boundary state.

[0042] For step S110, the structure of the test fixture is designed according to the dynamic stiffness simulation experiment of the suspension bushing. Specifically, the test fixture includes an upper clamp and a lower clamp, and the upper clamp and the lower clamp enclose a limiting space, and the limiting space is used to install the suspension bushing, wherein the upper clamp and the lower clamp each have three fixed surfaces, and every two fixed surfaces are arranged adjacent to each other, and the back side of each fixed surface is used to connect two bracket seats of a two-way dynamic stiffness test device, so that the two-way dynamic stiffness test device can apply a bidirectional load in the first direction, the second direction and the third direction to the suspension bushing.

[0043] For step S120, in order to avoid the influence of the vibration of the test fixture itself on the test results and improve the accuracy and reliability of the test results, the first-order modal frequency of the test fixture is greater than 1.5 times the upper limit of the frequency range to be tested. For example, the frequency range of the dynamic stiffness parameter test of the suspension bushing is 0-500Hz, and the first-order modal frequency of the test fixture with boundary state must be greater than 750Hz.

[0044] In an embodiment of the present invention, the mechanical performance data includes actual dynamic force, actual amplitude and phase angle of the suspension bushing.

[0045] In one embodiment of the present invention, step S400 includes: Step S410: controlling the two-way dynamic stiffness test device to apply a swept frequency excitation of a first frequency and a second frequency to the test fixture; Step S420: obtaining the bidirectional load on the suspension bushing under each frequency sweep excitation, and controlling the two-way dynamic stiffness test equipment to apply the bidirectional load in the first direction, the second direction and the third direction to the test fixture.

[0046] For step S410, the swept frequency excitation can cover the possible resonant frequencies of the suspension bushing, as well as the common vibration frequency range during vehicle driving, such as idle vibration, acceleration vibration, road noise, etc. By applying swept frequency excitations of different frequencies to the test fixture, the various vibration frequencies that the suspension bushing may encounter during actual work are simulated, thereby more comprehensively evaluating the dynamic stiffness characteristics of the suspension bushing.

[0047] For step S420, by measuring the actual dynamic force, actual amplitude and phase angle of the suspension bushing at different frequencies and loads, the dynamic stiffness parameters and dynamic damping coefficient of the suspension bushing can be calculated, thereby evaluating the vibration isolation performance of the suspension bushing. Through sweep frequency excitation and data analysis, the mechanical performance of the suspension bushing at different frequencies and loads can be obtained, providing important data support for the NVH performance design of the entire vehicle.

[0048]

[0049] Through the above data, the dynamic stiffness data performance of the suspension bushing under the vehicle's 3rd gear full throttle acceleration and the vehicle's 2nd gear slow throttle acceleration are obtained.

[0050] The present invention further provides a test fixture, comprising an upper fixture 10 and a lower fixture 20; the upper fixture 10 comprises first fixing surfaces 11 along a first direction, a second direction and a third direction respectively, the lower fixture 20 comprises a second fixing surface 21 adapted to the first fixing surface 11 along each direction, and any two opposite first fixing surfaces 11 and second fixing surfaces 21 can be connected to a suspension bushing; Among them, the back side of any one of the first fixed surfaces 11 of the upper clamp 10 is configured to be connected to the upper support of the test bench of the two-way dynamic stiffness testing equipment, and the back side of any one of the second fixed surfaces 21 of the lower clamp 20 is configured to be connected to the lower support of the test bench of the two-way dynamic stiffness testing equipment.

[0051] Specifically, each fixing surface of the upper fixture 10 and the lower fixture 20 is provided with a plurality of screw holes for screwing the support on the test bench, the support under the test bench and the suspension bushing. Figures 7 to 9 As shown, a set of test fixtures is used to test the two-way preload dynamic stiffness of the suspension bushing in three translational directions. The test fixture has a simple structure and is easy to install in different directions. It also has the characteristics of strong applicability, wide test frequency range and high test result accuracy.

[0052] The above are only exemplary embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A suspension bushing testing method, characterized in that: The suspension bushing test method includes: According to different working conditions of the car, the static support reaction force F of the suspension bushing is obtained. n mj ; According to the static support reaction force F n mj , a two-way dynamic stiffness test device applies a bidirectional load in a first direction, a second direction and a third direction to the suspension bushing, wherein the first direction, the second direction and the third direction are perpendicular to each other; Acquiring mechanical performance data of the suspension bushing under each of the bidirectional loads; According to the mechanical performance data, the dynamic stiffness parameter k of the suspension bushing is calculated. n dmj .

2. The suspension bushing testing method according to claim 1, characterized in that: Before the step of obtaining the mechanical performance data of the suspension bushing under each of the bidirectional loads, the method further includes: Fixing the suspension bushing on a test fixture, wherein the test fixture is connected to a two-way dynamic stiffness test device; The two-way dynamic stiffness testing device is driven to apply the two-way loads in the first direction, the second direction and the third direction to the testing fixture.

3. The suspension bushing testing method according to claim 1, characterized in that: The static support reaction force of the suspension bushing is obtained according to different working conditions of the automobile, including: According to different working conditions of the car, different wheel torque T of the car is obtained. n w ; According to the wheel side moment T n w , the static support reaction force F of the suspension bushing in the first direction, the second direction and the third direction is obtained n mj .

4. The suspension bushing testing method according to claim 3, characterized in that: According to each of the wheel side moments T n w , the static support reaction force F of the suspension bushing in the first direction, the second direction and the third direction is obtained n mj ,include: According to the wheel side moment T n w , the powertrain gravity is applied at the center of mass of the vehicle powertrain and the wheel torque T is applied at the axis of the engine crankshaft n w ; When the suspension bushing reaches static equilibrium, the static support reaction force F of the suspension bushing in the first direction, the second direction and the third direction is calculated. n mj .

5. The suspension bushing testing method according to claim 3, characterized in that: According to different working conditions of the vehicle, different wheel side torques T of the vehicle are obtained. n w ,include: According to different working conditions of the car, the output torque T of the car engine under each working condition is obtained. n e , the speed ratio of the transmission n t , speed ratio of the main reducer i n r And the transmission efficiency η of the automobile transmission system n ; According to the calculation formula, different wheel torques T of the car are obtained. n w .

6. The suspension bushing testing method according to claim 2, characterized in that: The suspension bushing is fixed on a test fixture, and the test fixture is connected to a two-way dynamic stiffness test device, including: The two connecting surfaces of the suspension bushing along the first direction, the second direction and the third direction are respectively fixed to two matching fixing surfaces on the test fixture, and the back surfaces of any two fixing surfaces in each direction are respectively connected to the two-way dynamic stiffness test equipment.

7. The suspension bushing testing method according to claim 6, characterized in that: Before the step of fixing the suspension bushing on the test fixture and connecting the test fixture to the two-way dynamic stiffness test equipment, the method further includes: Designing the test fixture according to the dynamic stiffness simulation experiment of the suspension bushing; A constrained modal analysis is performed on the test fixture with boundary states.

8. The suspension bushing testing method according to claim 1, characterized in that: The mechanical performance data includes the actual dynamic force, actual amplitude and phase angle of the suspension bushing.

9. The suspension bushing testing method according to claim 2, characterized in that: The step of controlling the two-way dynamic stiffness testing device to apply a bidirectional load in the first direction, the second direction and the third direction to the testing fixture comprises: Controlling the two-way dynamic stiffness testing device to apply a swept frequency excitation of a first frequency and a second frequency to the testing fixture; The bidirectional load on the suspension bushing under each frequency sweep excitation is obtained, and the two-way dynamic stiffness test equipment is controlled to apply bidirectional loads in the first direction, the second direction and the third direction to the test fixture.

10. A test tool, applied to the suspension bushing test method according to any one of claims 1 to 9, characterized in that: The test fixture comprises an upper fixture and a lower fixture; the upper fixture comprises first fixing surfaces respectively along a first direction, a second direction and a third direction, and the lower fixture comprises a second fixing surface adapted to the first fixing surface along each direction, and any two opposite first fixing surfaces and second fixing surfaces can be connected to the connection surface of the suspension bushing; Among them, the back side of any one of the first fixing surfaces of the upper clamp is configured to be connected to the upper support of the two-way dynamic stiffness testing device, and the back side of any one of the second fixing surfaces of the lower clamp is configured to be connected to the lower support of the two-way dynamic stiffness testing device.

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