Suspension vibration isolation NVH durability attenuation evaluation method

Abstract

The invention relates to the technical field of automobile suspension, in particular to a suspension vibration isolation NVH durability attenuation evaluation method. Comprising the following steps: before an endurance test, acquiring a first vibration isolation rate and a first vibration value of each suspension at each rotating speed point in a set rotating speed range under an experiment condition; after the endurance test, acquiring a second vibration isolation rate and a second vibration value of each suspension at each rotating speed point in a set rotating speed range under the experimental condition; determining an evaluation value of the engine mount based on the first vibration isolation rate, the second vibration isolation rate, the first vibration value and the second vibration value; and comparing the evaluation value with a set standard, and evaluating the NVH durability attenuation of the engine mount according to a comparison result. The evaluation method is simple, the NVH attenuation of the engine mount after the endurance test is evaluated and analyzed in two aspects, the change condition of the engine mount after the endurance test can be visually and accurately obtained, and the use condition of the engine mount can be conveniently and accurately analyzed.

Description

Technical Field

[0001] The present application relates to the technical field of automobile suspension, and specifically to a suspension vibration isolation NVH durability attenuation evaluation method. Background Art

[0002] With the development of society, cars have entered thousands of households. As an important part of the automobile powertrain, the engine mount not only bears the force and torque from the road and the engine, but also can mitigate the impact caused by the vibration. In order to withstand the impact caused by vibration for a long time and ensure the safety and stability of the car during driving, the engine mount must have sufficient rigidity and good durability. The engine mount system needs at least the following functions: withstand all dynamic forces and torques acting on the inside and outside of the powertrain during the driving of the car; isolate the vibration caused by the road and engine excitation, and reduce the damage caused by the vibration to the body and powertrain.

[0003] However, when the vehicle is traveling on an uneven road, the engine mount will be subjected to dual vibrations from the engine and the road, causing the engine mount to bear the vibration load for a long time, resulting in fatigue damage, which directly affects the service life of the vehicle. In addition, the vibration of the engine will also increase the noise inside the vehicle, seriously affecting the NVH performance of the vehicle. Currently, half of the new energy vehicles in China are extended-range vehicles or plug-in hybrid vehicles. The engine is charged or driven, and the engine is mounted on the vehicle body through the mount. When the new energy vehicle is low on power, the engine causes obvious noise inside the vehicle. After the vehicle has been durable and has a high mileage (3 years or 100,000 kilometers), the vibration isolation characteristics of the engine mount deteriorate, resulting in significantly louder noise inside the vehicle when the engine is working at low power, such as Figure 1 shown.

[0004] Therefore, in the early stages of automobile design, it is essential to fully verify the durability of the engine mount. However, at present, the existing durability verification analysis of the engine mount is more about analyzing the performance structure of the mount, and the analysis of the impact of the mount on the vehicle NVH before and after the durability test is not in-depth. Usually, only a general situation is obtained one-sidedly, that is, after the durability test, it is concluded that the NVH performance of the vehicle has decreased, but the specific decrease is not intuitively reflected. There is a lack of a reasonable evaluation system for the vibration isolation effect of the engine mount before and after the durability test, and it is impossible to more scientifically and reasonably evaluate the NVH attenuation of the engine mount after the durability test, which is not conducive to the selection and design of the engine mount in the early stages of automobile design. Summary of the invention

[0005] The purpose of this application is to address the deficiencies of the above-mentioned background technology and to provide a suspension vibration isolation NVH durability attenuation evaluation method.

[0006] The technical solution of the present application is: a suspension vibration isolation NVH durability attenuation evaluation method, comprising:

[0007] Before the durability test, obtain the first vibration isolation rate and the first vibration value of each mount at each direction and at each speed point within the set speed range under experimental conditions;

[0008] After the endurance test, the second vibration isolation rate and the second vibration value of each mount at each direction and each speed point within the set speed range under experimental conditions are obtained;

[0009] determining an evaluation value of the engine mount based on the first vibration isolation rate, the second vibration isolation rate, the first vibration value, and the second vibration value;

[0010] The evaluation value is compared with the set standard, and the engine mount NVH durability attenuation is evaluated based on the comparison result.

[0011] According to a suspension vibration isolation NVH durability attenuation evaluation method provided by the present application, the method for determining the evaluation value of the engine mount based on the first vibration isolation rate, the second vibration isolation rate, the first vibration value and the second vibration value comprises: calculating the first comprehensive vibration isolation rate of the engine mount based on the first vibration isolation rate of each mount in different directions and at different speeds, calculating the second comprehensive vibration isolation rate of the engine mount based on the second vibration isolation rate of each mount in different directions and at different speeds, and obtaining the difference between the first comprehensive vibration isolation rate and the second comprehensive vibration isolation rate as the vibration isolation rate attenuation value of the engine mount;

[0012] Calculate the difference between the second vibration value and the first vibration value of each mount in the same direction and at the same speed as the initial vibration difference, and obtain the vibration deterioration value of the engine mount based on the initial vibration difference of each mount in different directions and at different speeds;

[0013] The vibration isolation rate attenuation value and vibration deterioration value of the engine mount are used as evaluation values ​​of the engine mount.

[0014] According to a suspension vibration isolation NVH durability attenuation evaluation method provided by the present application, the method for calculating the first comprehensive vibration isolation rate of the engine suspension includes: obtaining the first vibration isolation rate based on the vibration values ​​of the active end and the passive end of the suspension in the same direction and at the same speed point; obtaining the first initial vibration isolation rate of a certain suspension in a certain direction based on the first vibration isolation rate of the suspension at all speed points within a set speed range; calculating the first comprehensive vibration isolation rate of the engine suspension based on the first initial vibration isolation rates of all suspensions in the engine suspension in all directions.

[0015] According to a suspension vibration isolation NVH durability attenuation evaluation method provided by the present application, the method for obtaining the first vibration isolation rate includes: calculating the first vibration isolation rate according to the following formula:

[0016] ΔVf1 =V a1 -V p1

[0017] Where: ΔV f1 ——The first vibration isolation rate of a certain suspension in a certain direction and at a certain speed;

[0018] V a1 ——Vibration value of a certain mount before endurance test at the active end in a certain direction and speed;

[0019] V p1 ——The vibration value of a certain mount before the passive endurance test in a certain direction and at a certain speed.

[0020] According to a suspension vibration isolation NVH durability attenuation evaluation method provided by the present application, the method for obtaining the first initial vibration isolation rate includes: calculating the first initial vibration isolation rate according to the following formula:

[0021]

[0022] Where: ΔV g1 ——The first initial vibration isolation rate of a certain suspension in a certain direction;

[0023] ΔV f1 ——The first vibration isolation rate of a certain suspension in a certain direction and at a certain speed;

[0024] i——rotational speed;

[0025] n1——minimum speed of the set speed range;

[0026] n2——The maximum speed in the set speed range.

[0027] According to a suspension vibration isolation NVH durability attenuation evaluation method provided by the present application, the method for obtaining the first comprehensive vibration isolation rate includes: calculating the first comprehensive vibration isolation rate according to the following formula:

[0028]

[0029] Where: ΔV zg1 ——The first comprehensive vibration isolation rate of the engine mount;

[0030] ΔV g1 ——The first initial vibration isolation rate of a certain suspension in a certain direction;

[0031] K j ——Vibration isolation coefficient of a certain suspension in a certain direction.

[0032] According to a suspension vibration isolation NVH durability attenuation evaluation method provided in the present application, the method for calculating the vibration deterioration value includes: obtaining the intermediate vibration difference of a certain suspension in a certain direction at all speed points within a set speed range based on the initial vibration difference of the rotation in this direction; calculating the vibration deterioration value of the engine suspension based on the intermediate vibration difference of all suspensions in the engine suspension in all directions.

[0033] According to a suspension vibration isolation NVH durability attenuation evaluation method provided by the present application, the method for calculating the initial vibration difference includes: calculating the initial vibration difference according to the following formula:

[0034] ΔV z =V h -V q

[0035] Where: ΔV z ——The initial vibration difference of a certain suspension in a certain direction and at a certain speed;

[0036] V h - vibration value of a certain mount after endurance test in a certain direction and at a certain speed;

[0037] V q ——The vibration value of a certain suspension before the endurance test in a certain direction and at a certain speed.

[0038] According to a suspension vibration isolation NVH durability attenuation evaluation method provided by the present application, the method for calculating the intermediate vibration difference includes: calculating the intermediate vibration difference according to the following formula:

[0039]

[0040] Where: ΔV d ——The intermediate vibration difference of a certain suspension in a certain direction;

[0041] ΔV z ——The initial vibration difference of a certain suspension in a certain direction and at a certain speed;

[0042] i——rotational speed;

[0043] n1——minimum speed of the set speed range;

[0044] n2——The maximum speed in the set speed range.

[0045] According to a suspension vibration isolation NVH durability attenuation evaluation method provided by the present application, the method for calculating the vibration deterioration value includes: calculating the vibration deterioration value according to the following formula:

[0046]

[0047] Where: ΔV eh - vibration deterioration value of engine mount;

[0048] ΔV d ——The intermediate vibration difference of a certain suspension in a certain direction;

[0049] K m ——The vibration difference coefficient of a certain suspension in a certain direction.

[0050] According to a suspension vibration isolation NVH durability attenuation evaluation method provided by the present application, the method for evaluating the engine suspension NVH durability attenuation based on the comparison results includes: if the evaluation value is not greater than the first set value, it is considered that the engine suspension NVH is in good condition; if the evaluation value is greater than the first set value and not greater than the second set value, it is considered that the engine suspension NVH is slightly deteriorated and acceptable; if the evaluation value is greater than the second set value and not greater than the third set value, it is considered that the engine suspension NVH is moderately deteriorated and acceptable; if the evaluation value is greater than the third set value, it is considered that the engine suspension NVH is severely deteriorated and needs to be replaced with new parts.

[0051] The advantages of this application are as follows: 1. This application evaluates and analyzes the NVH attenuation of the engine mount by collecting the vibration conditions of the engine mount before and after the endurance test. This application determines the evaluation value of the engine mount from two aspects: one is the vibration isolation rate of the engine mount, and the other is the vibration condition of the engine mount. The vibration conditions of the engine mount before and after the endurance test can be accurately obtained, and analyzed to accurately evaluate the NVH attenuation of the engine mount after the endurance test, and determine whether the engine mount needs to be replaced after the endurance test. This application can be applied to the design and selection of the engine mount, and provide a more intuitive and quantitative indicator for the selection of the engine mount.

[0052] 2. The method of obtaining the evaluation value in the present application is very simple. The present application calculates the vibration isolation rate attenuation value of the engine mount before and after the endurance test based on the vibration isolation rate, and calculates the vibration deterioration value of the engine mount before and after the endurance test based on the vibration value. The vibration condition of the engine mount is analyzed from two aspects. Based on these two parameters, the final evaluation value that can evaluate the engine mount after the endurance test can be obtained, which is convenient for accurately evaluating the NVH attenuation condition of the engine mount after the endurance test, and quantitatively analyzing the NVH attenuation condition, providing more intuitive data;

[0053] 3. The method for obtaining the first comprehensive vibration isolation rate of the present application is very simple. The calculation of the first comprehensive vibration isolation rate of the present application is performed step by step. First, the first vibration isolation rate of a certain mount in the same direction and at the same speed is calculated, and then the first initial vibration isolation rate of the mount in a certain direction is calculated. Finally, the first initial vibration isolation rate is summarized and calculated to obtain the first comprehensive vibration isolation rate. The first comprehensive vibration isolation rate reflects the vibration isolation condition of the engine mount before the endurance test. The calculation logic is simple and the calculation is accurate. The actual vibration isolation condition of the engine mount before the endurance test can be accurately obtained, which is convenient for comparison with the vibration isolation condition after the endurance test, so as to accurately judge the vibration isolation change of the engine mount before and after the endurance test.

[0054] 4. The calculation of the first vibration isolation rate of the mount in this application is based on the difference in vibration values ​​between the active end and the passive end of the mount in a certain direction and at a certain speed. In fact, it represents the attenuation of the engine mount vibration at the active end and the passive end. The attenuation corresponds to the vibration isolation of the engine mount. In this way, the vibration isolation of the mount in a certain direction and at a certain speed can be accurately obtained;

[0055] 5. The present application can obtain the vibration isolation condition of the mount in a certain direction by summarizing and calculating the first vibration isolation rate at all speed points within a set speed range of the mount in a certain direction. The calculation method is simple, and the obtained first initial vibration isolation rate accurately reflects the vibration isolation condition of the mount in the direction before the endurance test, which is convenient for vibration isolation analysis of the engine mount.

[0056] 6. The present application summarizes and calculates the first initial vibration isolation rates of all mounts in all directions, and thus the vibration isolation of the engine mount before the endurance test, i.e., the first comprehensive vibration isolation rate of the present application, can be obtained. The vibration isolation after the endurance test can be obtained in the same way, i.e., the second comprehensive vibration isolation rate of the present application. By comparing the first comprehensive vibration isolation rate with the second comprehensive vibration isolation rate, the vibration isolation change of the engine mount after the endurance test can be intuitively obtained.

[0057] 7. The method of calculating the vibration deterioration value in the present application is very simple. The calculation of the vibration deterioration value is carried out on the change of the vibration value of a certain suspension in a certain direction and at a certain speed before and after the endurance test. The vibration deterioration value can be obtained by analyzing the vibration change of each suspension in each direction and at each speed point, which can facilitate a more intuitive vibration change of the engine suspension after the endurance test and can quantitatively analyze the change;

[0058] 8. This application compares the vibration values ​​of a suspension before and after an endurance test in a certain direction and at a certain speed. The difference between the vibration values ​​before and after the endurance test can be used to obtain the vibration change of the suspension in the direction and at the speed, which is convenient for subsequent accurate analysis of the vibration change of the suspension before and after the endurance test.

[0059] 9. The present application summarizes the initial vibration difference of a certain suspension in a certain direction and at a certain speed, and summarizes the initial vibration difference of the suspension at all speed points in the direction, so as to accurately obtain the vibration change of the suspension before and after the endurance test in the direction. The calculation method is simple, and the actual vibration change of the suspension before and after the endurance test can be obtained, which is convenient for further analysis and judgment.

[0060] 10. The present application can obtain the vibration deterioration value of the engine mount by summarizing and calculating the intermediate vibration differences of all mounts in all directions. The vibration deterioration value of the engine mount can reflect the vibration changes of the engine mount on the vehicle before and after the endurance test, and provide data support for the subsequent NVH attenuation analysis of the engine mount. The entire calculation method is simple, and the calculation results can accurately reflect the actual vibration changes.

[0061] 11. This application can accurately and intuitively evaluate the NVH attenuation after the engine mount durability test by comparing the evaluation value with the set standard, and can determine whether the engine mount needs to be replaced after completing the durability test and whether it meets the requirements. This evaluation method enables testers and selectors to intuitively and accurately obtain the actual situation of the engine mount, which greatly facilitates the selection and design of the engine mount.

[0062] The evaluation method of the present application is simple. It evaluates and analyzes the NVH attenuation of the engine mount after the durability test from two aspects. It can intuitively and accurately obtain the changes in the engine mount after the durability test, facilitate accurate analysis of the use of the engine mount, and is beneficial to engine selection and design, and has great promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 : Comparison of noise data during acceleration in the vehicle before and after the engine mount endurance test;

[0064] Figure 2 : Vibration isolation rate curve of engine mount before endurance test;

[0065] Figure 3 : Vibration isolation rate curve of engine mount after endurance test;

[0066] Figure 4: Vibration difference curve of the engine mount body end before and after the endurance test. DETAILED DESCRIPTION

[0067] The embodiments of the present application are described in detail below, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0068] In the description of the present application, it should be understood that the terms "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0069] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0070] The present application is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0071] The present application relates to a suspension vibration isolation NVH durability attenuation evaluation method. The present application mainly analyzes the state of the engine suspension before and after the durability test. By analyzing the vibration isolation rate and vibration conditions of the engine suspension before and after the durability test, an NVH attenuation evaluation value that can reflect the engine suspension after the durability test is obtained. By comparing the evaluation value with the set standard, it is possible to accurately obtain whether the engine suspension meets the vehicle interior noise requirements after completing the durability test, and determine whether the engine suspension needs to be replaced after the durability test. The method can be applied to the design and selection of engine suspensions, and provide a more intuitive and quantitative indicator for engine suspension selection.

[0072] The engine mount includes three independent mounts, the left mount, the right mount and the torsion mount. Each mount involves vibration and vibration isolation in three directions, namely, X-direction vibration isolation and vibration of the left mount, Y-direction vibration isolation and vibration of the left mount, Z-direction vibration isolation and vibration of the left mount, X-direction vibration isolation and vibration of the right mount, Y-direction vibration isolation and vibration of the right mount, Z-direction vibration isolation and vibration of the torsion mount, X-direction vibration isolation and vibration of the torsion mount, Y-direction vibration isolation and vibration of the torsion mount and Z-direction vibration isolation and vibration of the torsion mount. The vibration isolation rate refers to the vibration difference between the active and passive ends of the mount vibration. After the vibration is transmitted from the active end to the passive end, it will attenuate, and the vibration value of the passive end is lower than that of the active end.

[0073] Specifically, a suspension vibration isolation NVH durability attenuation evaluation method of the present application includes the following steps:

[0074] S1. Before the durability test, obtain the first vibration isolation rate and the first vibration value of each suspension at each direction and at each speed point within the set speed range under experimental conditions;

[0075] Before the endurance test, a standard test condition is established, such as setting the engine speed, driving environment, and establishing the same vibration sampling points, etc., to ensure that the sampling conditions remain unchanged and eliminate the interference of other factors on the test results; the first vibration isolation rate is actually also obtained based on the vibration value;

[0076] The set speed range of this application is 1200RPM~6000RPM. In actual application, it is not limited to this speed range. It only needs to meet the actual needs. The speed point is selected from the set speed range for sampling. For example, sampling can be performed every 100RPM, or other interval speeds can be selected for sampling;

[0077] S2. After the durability test, obtain the second vibration isolation rate and the second vibration value of each suspension at each direction and each speed point within the set speed range under the experimental conditions;

[0078] Similarly, after the endurance test, the same experimental conditions were constructed to sample the vibration of the suspension, and the second vibration isolation rate was also obtained based on the vibration value;

[0079] S3, determining an evaluation value of the engine mount based on the first vibration isolation rate, the second vibration isolation rate, the first vibration value, and the second vibration value;

[0080] The vibration isolation rate reflects the vibration change between the two ends of the mount, and the vibration value corresponds to the vibration of the mount itself. This application analyzes the engine mount from two aspects, namely, the vibration isolation rate change and the vibration change before and after the durability test, and combines the two changes to perform analysis and calculation, thereby obtaining the evaluation value of the engine mount;

[0081] S4. Compare the evaluation value with the set standard, and evaluate the engine mount NVH durability attenuation based on the comparison result.

[0082] The present application obtains the evaluation value of the engine mount after the durability test through the vibration isolation rate and the vibration value, quantifies the NVH attenuation of the engine mount after completing the durability test, and analyzes the quantified evaluation value, so as to intuitively determine whether the current engine mount meets the NVH attenuation requirements. If it does not meet the requirements, the engine mount needs to be replaced, or it is considered that the current engine mount does not meet the requirements of the vehicle model. This can intuitively facilitate experimenters or designers to judge the engine mount, which is beneficial to the design and selection of the engine mount.

[0083] In some embodiments of the present application, this embodiment optimizes the above-mentioned step S1 and step S2. This embodiment samples the vibration conditions of the engine mount before and after the endurance test, sets a vibration sensor in each direction of each mount of the engine mount, and installs vibration sensors at the passive and active ends of each mount of the engine mount to collect vibration values ​​of the engine mount before and after the endurance test.

[0084] The first vibration isolation rate is the difference between the vibration values ​​of the active end and the passive end of the suspension. The method for obtaining the first vibration isolation rate is: calculate the first vibration isolation rate according to the following formula:

[0085] ΔV f1 =V a1 -V p1

[0086] Where: ΔV f1 ——The first vibration isolation rate of a certain suspension in a certain direction and at a certain speed;

[0087] V a1 ——Vibration value of a certain mount before endurance test at the active end in a certain direction and speed;

[0088] V p1 ——The vibration value of a certain mount before the passive endurance test in a certain direction and at a certain speed.

[0089] The same method for obtaining the second vibration isolation rate is:

[0090] The second vibration isolation rate is calculated according to the following formula:

[0091] ΔV f2 =V a2 -V p2

[0092] Where: ΔV f2 ——The second vibration isolation rate of a certain suspension in a certain direction and at a certain rotation speed;

[0093] V a2 ——Vibration value of a certain mount after endurance test at the active end in a certain direction and speed;

[0094] V p2 ——The vibration value of a certain suspension after the passive end endurance test in a certain direction and at a certain speed.

[0095] The above method can be used to obtain the first vibration isolation rate and the second vibration isolation rate of the mount in a certain direction and at a certain rotation speed. The vibration isolation rate reflects the vibration attenuation value between the active end and the passive end of the engine mount.

[0096] In a further embodiment of the present application, this embodiment optimizes the above-mentioned step S3. This embodiment determines the evaluation value of the engine mount based on the first vibration isolation rate, the second vibration isolation rate, the first vibration value and the second vibration value. The method is as follows: the first comprehensive vibration isolation rate of the engine mount is calculated based on the first vibration isolation rate of each mount in different directions and at different speeds, and the second comprehensive vibration isolation rate of the engine mount is calculated based on the second vibration isolation rate of each mount in different directions and at different speeds, and the difference between the first comprehensive vibration isolation rate and the second comprehensive vibration isolation rate is obtained as the vibration isolation rate attenuation value of the engine mount; the difference between the second vibration value and the first vibration value of each mount in the same direction and at the same speed is calculated as the initial vibration difference, and the vibration deterioration value of the engine mount is obtained based on the initial vibration difference of each mount in different directions and at different speeds; the vibration isolation rate attenuation value and the vibration deterioration value of the engine mount are used as the evaluation value of the engine mount.

[0097] The method for calculating the first comprehensive vibration isolation rate is as follows: based on the vibration values ​​of the active end and the passive end of the suspension in the same direction and at the same speed point, the first vibration isolation rate is obtained, that is, the calculation of the first vibration isolation rate and the second vibration isolation rate as described above; based on the first vibration isolation rate of a certain suspension at all speed points within a set speed range in a certain direction, the first initial vibration isolation rate of the suspension in the direction is obtained, and the first initial vibration isolation rate is calculated specifically according to the following formula, as follows: Figure 2 As shown:

[0098]

[0099] Where: ΔV g1 ——The first initial vibration isolation rate of a certain suspension in a certain direction;

[0100] ΔV f1 ——The first vibration isolation rate of a certain suspension in a certain direction and at a certain speed;

[0101] i——rotational speed;

[0102] n1——minimum speed of the set speed range;

[0103] n2——the maximum speed of the set speed range;

[0104] Then, the first comprehensive vibration isolation rate of the engine mount is calculated based on the first initial vibration isolation rates of all mounts in the engine mount in all directions. Specifically, the first comprehensive vibration isolation rate is calculated according to the following formula:

[0105]

[0106] Where: ΔV zg1 ——The first comprehensive vibration isolation rate of the engine mount;

[0107] ΔV g1 ——The first initial vibration isolation rate of a certain suspension in a certain direction;

[0108] K j ——Vibration isolation coefficient of a certain suspension in a certain direction.

[0109] Similarly, the second comprehensive vibration isolation rate of this embodiment is calculated according to the above method: based on the second vibration isolation rate of a certain suspension at all speed points within a set speed range in a certain direction, the second initial vibration isolation rate of the suspension in the direction is obtained. Specifically, the second initial vibration isolation rate is calculated according to the following formula, such as Figure 3 As shown:

[0110]

[0111] Where: ΔV g2 ——The second initial vibration isolation rate of a certain suspension in a certain direction;

[0112] ΔV f2 ——The second vibration isolation rate of a certain suspension in a certain direction and at a certain rotation speed;

[0113] i——rotational speed;

[0114] n1——minimum speed of the set speed range;

[0115] n2——the maximum speed of the set speed range;

[0116] Then, based on the second initial vibration isolation rates of all the mounts in the engine mounts in all directions, the second comprehensive vibration isolation rate of the engine mount is calculated. Specifically, the second comprehensive vibration isolation rate is calculated according to the following formula:

[0117]

[0118] Where: ΔV zg2 ——The second comprehensive vibration isolation rate of the engine mount;

[0119] ΔV g2——The second initial vibration isolation rate of a certain suspension in a certain direction;

[0120] K j ——Vibration isolation coefficient of a certain suspension in a certain direction.

[0121] At this point, the first comprehensive vibration isolation rate and the second comprehensive vibration isolation rate of the engine mount can be obtained. The first comprehensive vibration isolation rate represents the vibration isolation of the engine mount before the endurance test, and the second comprehensive vibration isolation rate represents the vibration isolation of the engine mount after the endurance test. Generally speaking, the vibration isolation of the engine mount will weaken after the endurance test. Under normal circumstances, the first comprehensive vibration isolation rate of the same engine mount is greater than the second comprehensive vibration isolation rate. The difference between the first comprehensive vibration isolation rate and the second comprehensive vibration isolation rate is the vibration isolation rate attenuation value of the engine mount. The vibration isolation rate attenuation value represents the attenuation of the vibration isolation effect of the engine mount after the endurance test.

[0122] K in this embodiment j It is the contribution coefficient of the mount in a certain direction to the overall vibration isolation rate of the engine mount. This coefficient is obtained by constructing a standard test. For specific coefficients, see Table 1:

[0124] Table 1: Vibration isolation coefficient table for suspension in a certain direction

[0125]

[0126] In a preferred embodiment of the present application, the present embodiment optimizes the above-mentioned method for calculating the vibration deterioration value. Specifically, the method for calculating the vibration deterioration value is: the difference between the second vibration value and the first vibration value of each suspension in the same direction and at the same speed is calculated as the initial vibration difference value, and the initial vibration difference value is calculated specifically according to the following formula:

[0127] ΔV z =V h -V q

[0128] Where: ΔV z ——The initial vibration difference of a certain suspension in a certain direction and at a certain speed;

[0129] V h - vibration value of a certain mount after endurance test in a certain direction and at a certain speed;

[0130] V q - vibration value of a certain mount before endurance test in a certain direction and at a certain speed;

[0131] Based on the initial vibration difference of a certain suspension at all speed points within a set speed range in a certain direction, the intermediate vibration difference of the rotation in this direction is obtained, such as Figure 3As shown, the initial vibration difference is calculated according to the following formula:

[0132]

[0133] Where: ΔV d ——The intermediate vibration difference of a certain suspension in a certain direction;

[0134] ΔV z ——The initial vibration difference of a certain suspension in a certain direction and at a certain speed;

[0135] i——rotational speed;

[0136] n1——minimum speed of the set speed range;

[0137] n2——the maximum speed of the set speed range;

[0138] The vibration deterioration value of the engine mount is calculated based on the intermediate vibration difference of all mounts in all directions of the engine mount. Specifically, the vibration deterioration value is calculated according to the following formula:

[0139]

[0140] Where: ΔV eh - vibration deterioration value of engine mount;

[0141] ΔV d ——The intermediate vibration difference of a certain suspension in a certain direction;

[0142] K m ——The vibration difference coefficient of a certain suspension in a certain direction.

[0143] The calculation methods of vibration deterioration value and vibration isolation rate attenuation value are different. The calculation of vibration isolation rate attenuation value is to first calculate the comprehensive vibration isolation rate before the endurance test, and then compare it with the comprehensive vibration isolation rate after the endurance test. The vibration deterioration value is to directly compare the vibration value before the endurance test and the vibration value after the endurance test of a certain suspension in a certain direction and a certain speed, and then summarize the comparison results to obtain the required vibration deterioration value.

[0144] K in this embodiment m It is the contribution coefficient of the mount in a certain direction to the overall vibration difference of the engine mount. This coefficient is obtained by constructing a standard test. For specific coefficients, see Table 2:

[0145] Table 2: Vibration difference coefficient table of the suspension body end in a certain direction

[0146]

[0147] In other embodiments of the present application, this embodiment optimizes the above-mentioned step S4, and the method for evaluating the durable attenuation of the engine suspension NVH according to the comparison result is: if the evaluation value is not greater than the first set value, it is considered that the engine suspension NVH is in good condition; if the evaluation value is greater than the first set value and not greater than the second set value, it is considered that the engine suspension NVH is slightly deteriorated and acceptable; if the evaluation value is greater than the second set value and not greater than the third set value, it is considered that the engine suspension NVH is moderately deteriorated and acceptable; if the evaluation value is greater than the third set value, it is considered that the engine suspension NVH is severely deteriorated and needs to be replaced with new parts.

[0148] The vibration deterioration value and the vibration isolation rate attenuation value represent two aspects of the engine mount, which affect the in-vehicle noise, namely the NVH performance. The vibration of the engine mount is the main cause of the in-vehicle noise, and the vibration isolation of the engine mount can reduce the in-vehicle noise. Analyzing and evaluating the engine mount from these two aspects can accurately reflect the impact of the engine mount on the in-vehicle noise after the durability test, so as to judge whether the engine mount meets the NVH attenuation requirements.

[0149] This embodiment calculates the sum of the vibration deterioration value and the vibration isolation rate attenuation value as the evaluation value, and then compares the evaluation value with the set standard. The set standard of this embodiment is the standard range, which is obtained through a large number of standard tests. The set standard includes three set values, namely the first set value, the second set value and the third set value. The first set value of this embodiment can be set to 5dBm / s 2 , the second setting value can be set to 15dBm / s 2 , the third setting value can be set to 28dBm / s 2 In actual application, it is not limited to the above setting values ​​and can be selected according to the actual situation as long as it meets the needs.

[0150] Specifically, the NVH attenuation determination results before and after the engine mount durability test of this embodiment can be seen in Table 3:

[0151] Table 3: NVH attenuation determination table before and after engine mount durability test

[0152]

[0153] The suspension vibration isolation NVH durability attenuation evaluation method of the present application is actually operated as follows: before the durability test, the first vibration isolation rate and the first vibration value of each suspension in each direction and at each speed point within the set speed range under the experimental conditions are obtained; after the durability test, the second vibration isolation rate and the second vibration value of each suspension in each direction and at each speed point within the set speed range under the experimental conditions are obtained; the first vibration isolation rate and the second vibration isolation rate are calculated according to the above method; the first comprehensive vibration isolation rate of the engine suspension is calculated based on the first vibration isolation rate of each suspension in different directions and at different speeds, and the second comprehensive vibration isolation rate of the engine suspension is calculated based on the second vibration isolation rate of each suspension in different directions and at different speeds, and the difference between the first comprehensive vibration isolation rate and the second comprehensive vibration isolation rate is obtained as the vibration isolation rate attenuation value of the engine mount; the second vibration isolation rate of each suspension in the same direction and at the same speed is calculated The difference between the value and the first vibration value is the initial vibration difference; the intermediate vibration difference of a certain suspension at all speed points within a set speed range in a certain direction is obtained; the vibration deterioration value of the engine suspension is calculated based on the intermediate vibration difference of all suspensions in the engine suspension in all directions; the vibration isolation rate attenuation value and the vibration deterioration value of the engine suspension are used as the evaluation value of the engine suspension; if the evaluation value is not greater than the first set value, it is considered that the NVH state of the engine suspension is good; if the evaluation value is greater than the first set value and not greater than the second set value, it is considered that the NVH of the engine suspension is slightly deteriorated and acceptable; if the evaluation value is greater than the second set value and not greater than the third set value, it is considered that the NVH of the engine suspension is moderately deteriorated and acceptable; if the evaluation value is greater than the third set value, it is considered that the NVH of the engine suspension is severely deteriorated and needs to be replaced with new parts.

[0154] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited by the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present application. The present application may have various changes and improvements without departing from the spirit and scope of the present application, and these changes and improvements fall within the scope of the present application to be protected. The scope of protection claimed in the present application is defined by the attached claims and their equivalents.

Claims

1. A suspension vibration isolation NVH durability attenuation evaluation method, characterized by: include, Before the durability test, obtain the first vibration isolation rate and the first vibration value of each mount at each direction and at each speed point within the set speed range under experimental conditions; After the endurance test, the second vibration isolation rate and the second vibration value of each mount at each direction and each speed point within the set speed range under experimental conditions are obtained; determining an evaluation value of the engine mount based on the first vibration isolation rate, the second vibration isolation rate, the first vibration value, and the second vibration value; The evaluation value is compared with the set standard, and the engine mount NVH durability attenuation is evaluated based on the comparison result.

2. A suspension vibration isolation NVH durability attenuation evaluation method as claimed in claim 1, characterized in that: The method for determining the evaluation value of the engine mount based on the first vibration isolation rate, the second vibration isolation rate, the first vibration value and the second vibration value comprises: calculating the first comprehensive vibration isolation rate of the engine mount based on the first vibration isolation rate of each mount in different directions and at different speeds, calculating the second comprehensive vibration isolation rate of the engine mount based on the second vibration isolation rate of each mount in different directions and at different speeds, and obtaining the difference between the first comprehensive vibration isolation rate and the second comprehensive vibration isolation rate as the vibration isolation rate attenuation value of the engine mount; Calculate the difference between the second vibration value and the first vibration value of each mount in the same direction and at the same speed as the initial vibration difference, and obtain the vibration deterioration value of the engine mount based on the initial vibration difference of each mount in different directions and at different speeds; The vibration isolation rate attenuation value and vibration deterioration value of the engine mount are used as evaluation values ​​of the engine mount.

3. A suspension vibration isolation NVH durability attenuation evaluation method as claimed in claim 2, characterized in that: The method for calculating the first comprehensive vibration isolation rate of the engine mount includes: obtaining the first vibration isolation rate based on the vibration values ​​of the active end and the passive end of the mount in the same direction and at the same speed point; obtaining the first initial vibration isolation rate of a certain mount in a certain direction based on the first vibration isolation rate of the mount at all speed points within a set speed range in a certain direction; and calculating the first comprehensive vibration isolation rate of the engine mount based on the first initial vibration isolation rates of all mounts in the engine mount in all directions.

4. A suspension vibration isolation NVH durability attenuation evaluation method as claimed in claim 3, characterized in that: The method for obtaining the first vibration isolation rate includes: calculating the first vibration isolation rate according to the following formula: ΔV f1 =V a1 -V p1 Where: ΔV f1 ——The first vibration isolation rate of a certain suspension in a certain direction and at a certain speed; V a1 ——Vibration value of a certain mount before endurance test at the active end in a certain direction and speed; V p1 ——The vibration value of a certain mount in a certain direction and at a certain speed before the passive endurance test.

5. The NVH durability attenuation evaluation method of suspension vibration isolation according to claim 3, characterized in that: The method for obtaining the first initial vibration isolation rate includes: calculating the first initial vibration isolation rate according to the following formula: Where: ΔV g1 ——The first initial vibration isolation rate of a certain suspension in a certain direction; ΔV f1 ——The first vibration isolation rate of a certain suspension in a certain direction and at a certain speed; i——rotational speed; n1——minimum speed of the set speed range; n2——The maximum speed in the set speed range.

6. A suspension vibration isolation NVH durability attenuation evaluation method as claimed in claim 3, characterized in that: The method for obtaining the first comprehensive vibration isolation rate includes: calculating the first comprehensive vibration isolation rate according to the following formula: Where: ΔV zg1 ——The first comprehensive vibration isolation rate of the engine mount; ΔV g1 ——The first initial vibration isolation rate of a certain suspension in a certain direction; K j ——Vibration isolation coefficient of a certain suspension in a certain direction.

7. The NVH durability attenuation evaluation method of suspension vibration isolation according to claim 2, characterized in that: The method for calculating the vibration deterioration value includes: obtaining the intermediate vibration difference of a certain suspension in a certain direction based on the initial vibration difference at all speed points within a set speed range in the certain direction; and calculating the vibration deterioration value of the engine suspension based on the intermediate vibration difference of all suspensions in the engine suspension in all directions.

8. The NVH durability attenuation evaluation method of suspension vibration isolation according to claim 7, characterized in that: The method for calculating the initial vibration difference includes: calculating the initial vibration difference according to the following formula: ΔV z =V h -V q Where: ΔV z ——The initial vibration difference of a certain suspension in a certain direction and at a certain speed; V h - vibration value of a certain mount after endurance test in a certain direction and at a certain speed; V q ——The vibration value of a certain suspension before the endurance test in a certain direction and at a certain speed.

9. The NVH durability attenuation evaluation method of suspension vibration isolation according to claim 7, characterized in that: The method for calculating the intermediate vibration difference includes: calculating the intermediate vibration difference according to the following formula: Where: ΔV d ——the difference of the intermediate vibration of a certain suspension in a certain direction; ΔV z ——The initial vibration difference of a certain suspension in a certain direction and at a certain speed; i——rotational speed; n1——minimum speed of the set speed range; n2——The maximum speed in the set speed range.

10. The NVH durability attenuation evaluation method of suspension vibration isolation according to claim 7, characterized in that: The method for calculating the vibration deterioration value includes: calculating the vibration deterioration value according to the following formula: Where: ΔV eh ——Vibration deterioration value of engine mount; ΔV d ——the difference of the intermediate vibration of a certain suspension in a certain direction; K m ——The vibration difference coefficient of a certain suspension in a certain direction.

11. The NVH durability attenuation evaluation method of suspension vibration isolation according to claim 1, characterized in that: The method for evaluating the durable attenuation of the engine suspension NVH according to the comparison result includes: if the evaluation value is not greater than the first set value, it is considered that the NVH state of the engine suspension is good; if the evaluation value is greater than the first set value and not greater than the second set value, it is considered that the slight deterioration of the NVH of the engine suspension is acceptable; if the evaluation value is greater than the second set value and not greater than the third set value, it is considered that the moderate deterioration of the NVH of the engine suspension is acceptable; if the evaluation value is greater than the third set value, it is considered that the NVH of the engine suspension is severely deteriorated and needs to be replaced with new parts.

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