A method for evaluating abnormal noise of a powertrain mounting system

Abstract

The application discloses a kind of abnormal sound evaluation methods of power assembly suspension system, comprising the following steps: power assembly suspension sample is installed to whole vehicle sample car;Point-off condition power assembly suspension abnormal sound evaluation is carried out on flat road;Whole vehicle is placed in test track, and bad road passing test is carried out, and power assembly suspension abnormal sound evaluation is carried out simultaneously;Whole vehicle sample car passes various bad road pavement at required speed, and the vibration acceleration of wheel knuckle is collected;Obtain the vibration spectrum of whole vehicle passing various bad road pavement;Whole vehicle sample car is placed in low-temperature environment bin, and point-off condition power assembly suspension abnormal sound evaluation is carried out;Whole vehicle sample car is placed on four-channel tire coupling road simulation machine, and power assembly suspension abnormal sound evaluation is carried out;Calculate the suspension abnormal sound score of whole vehicle driving condition and the suspension abnormal sound score of bench low-temperature condition, and finally calculate the suspension abnormal sound score.

Description

Technical Field

[0001] This invention belongs to the field of powertrain mounting technology, specifically relating to a method for evaluating abnormal noises in a powertrain mounting system. Background Technology

[0002] The powertrain mount's primary spring is made of rubber. In the vehicle's operating state, it mainly functions as a load-bearing element, vibration damper, and limiter. During use, it is subjected to various complex excitations and abnormal noises caused by rubber hardening at low temperatures. When the vehicle is turned off or when going over speed bumps, the powertrain mount is subjected to significant impacts, resulting in structural and impact noises. During vehicle operation, it encounters various rough roads, including but not limited to unrepaired roads, uneven roads, road ridges, small round bumps, concrete roads, washboard roads, cobblestone roads, Belgian roads, pothole roads, stepped or twisted roads, large round bumps, curved or twisted roads, smooth roads, and unrepaired roads in urban areas. These rough road conditions cause mount resonance, friction, and impact noises. At low temperatures, the rubber mount material hardens, increasing static and dynamic stiffness. The fluid inside the hydraulic mount cavity freezes, causing active and semi-active mount control modes to fail, resulting in abnormal mount noises.

[0003] Currently, domestic vehicle manufacturers lack a systematic evaluation method for powertrain mount development in terms of abnormal noise. In the early stages of mount development, the abnormal noise problems generated by the mount under the vehicle condition are not fully identified, which leads to structural changes in the later stages of mount development, affecting development costs and cycle. Summary of the Invention

[0004] To address the aforementioned problems in existing technologies, this invention provides a method for evaluating abnormal noises in powertrain mounting systems. Considering the various complex operating conditions encountered by powertrain mountings, a comprehensive and systematic evaluation method is proposed for various abnormal noise problems that may occur in the vehicle under full-vehicle conditions. It mainly starts from the vehicle driving conditions and low-temperature test bench conditions, covering all operating conditions. It can fully identify abnormal noise problems generated by powertrain mountings under various complex operating conditions in the vehicle, which has guiding significance for the early development of mountings and can avoid the development costs and cycle costs caused by changes in mounting design.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A method for evaluating abnormal noises in a powertrain mounting system includes the following steps:

[0007] S1. Prepare powertrain mounting samples and vehicle samples, and install the mounting samples onto the vehicle samples;

[0008] S2. Place the complete vehicle prototype on a flat surface and evaluate the powertrain mounting noise under start-stop conditions, recording the score Frs;

[0009] S3. Place the vehicle at the test track and conduct a rough road test. Simultaneously evaluate the abnormal noise of the powertrain mounting and record the scores Fr1, Fr2, Fr3...Fri for various rough road surfaces.

[0010] S4. Drive the prototype vehicle through various rough road surfaces at the required speed and collect the vibration acceleration D of the wheel steering knuckles;

[0011] S5. The vibration acceleration D of the wheel steering knuckle is used to obtain the vibration spectrum T of the whole vehicle passing through various bad road surfaces through a four-channel tire-coupled road simulator.

[0012] S6. Place the complete vehicle prototype in a low-temperature environment chamber to evaluate the abnormal noise of the powertrain mounting under the start-stop condition and record the score Fts;

[0013] S7. Place the complete vehicle prototype on a four-channel tire-coupled road simulator, stimulate the vehicle on the four-channel tire-coupled road simulator, evaluate the abnormal noise of the powertrain mounting, and record the scores Ft1, Ft2, Ft3...Fti when passing through various bad road surfaces;

[0014] S8. For the ignition-shutdown condition, Ps represents its usage frequency; for the bad road pass test, Pai represents the usage frequency of various bad road surfaces.

[0015] S9. Calculate the suspension noise score under vehicle driving conditions: Sr = Frs * Ps + ∑Fri * Pai; Calculate the suspension noise score under low temperature test conditions: St = Fts * Ps + ∑Fti * Pai; Calculate the suspension noise score: S = Sr + St.

[0016] Furthermore, in step S1, the suspended prototype must meet the design requirements for structure, size, and stiffness; the prototype vehicle must have the ability to drive in low temperatures and on rough roads.

[0017] Furthermore, when the suspension prototype is installed on the vehicle prototype, the installation torque Q is required to be ≥100Nm.

[0018] Furthermore, a rough road driving test was conducted to require the vehicle to pass through various rough road surfaces at required speeds. The road surface and speed requirements for the rough road driving test are as follows:

[0019]

[0020] Furthermore, in step S4, a vibration acceleration sensor is installed at the wheel steering knuckle position and connected to a vibration noise data acquisition system to collect the vibration acceleration D of the wheel steering knuckle.

[0021] Furthermore, in step S6, the ambient temperature is set to -30℃, and the system is left to stand for 12 hours before evaluating the abnormal noise of the powertrain mounting under ignition-shutdown conditions.

[0022] Furthermore, in step S7, the ambient temperature is set to -30℃, and the vehicle is left to stand for 12 hours. The entire vehicle is then stimulated on a four-channel tire-coupled road simulator using a vibration road spectrum T to evaluate abnormal noises from the powertrain mounting.

[0023] Furthermore, in step S8, the frequency of use of the road surface tested by the bad road is as follows:

[0024] Serial Number bad road surface Pai usage frequency 1 dilapidated road 0.3 2 Arched uneven road 0.1 3 Corner Railway 0.3 4 Small round protrusion 0.3 5 cement road 1 6 washboard road 0.1 7 cobblestone 0.1 8 Belgium 0.3 9 Fish Scale Pit 0.3 10 Twisted Stairs 0.1 11 Large round protrusion 0.1 12 Twisted Road 1 13 Smooth Road 1 14 dilapidated roads around the city 0.3

[0025] The present invention has the following advantages:

[0026] 1. This invention provides a comprehensive evaluation method for abnormal noises in powertrain mounting systems.

[0027] 2. This invention proposes two evaluation conditions for abnormal noises in the powertrain mounting system from the perspective of the whole vehicle: the start-stop condition and the bad road passage test condition.

[0028] 3. This invention innovatively proposes a powertrain mounting system abnormal noise rating, which can quantify the level of abnormal noise in the mounting system. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0030] Figure 1 This is a flowchart of a method for evaluating abnormal noises in a powertrain mounting system according to an embodiment of the present invention. Detailed Implementation

[0031] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0032] Example

[0033] like Figure 1 As shown, a method for evaluating abnormal noises in a powertrain mounting system includes the following steps:

[0034] Step 1: Prepare powertrain mount prototypes. The prototypes must meet the design requirements for structure, dimensions, and rigidity. Prepare a prototype vehicle, which must be capable of low-temperature and rough-road driving. Install the mount prototypes onto the prototype vehicle, requiring an installation torque Q ≥ 100 Nm.

[0035] Step 2: Place the prototype vehicle on a flat surface and evaluate the powertrain mounting noise under start-stop conditions, recording the score Frs.

[0036] Step 3: Place the vehicle at the test track and conduct a rough road driving test, requiring the vehicle to pass through various rough road surfaces at the specified speeds. The road surfaces and speed requirements for the rough road driving test are shown in Table 1. Simultaneously, evaluate powertrain mounting noise and record the scores Fr1, Fr2, Fr3...Fri for each rough road surface.

[0037] Table 1. Road surface and speed requirements for the bad road traversal test.

[0038]

[0039] Step 4: Install vibration acceleration sensors at the wheel steering knuckles and connect them to the vibration and noise data acquisition system. Drive the prototype vehicle at the required speed through various rough road surfaces and collect the vibration acceleration D of the wheel steering knuckles.

[0040] Arrangement 5: The vibration acceleration D of the wheel steering knuckle is used to obtain the vibration spectrum T of the whole vehicle passing through various bad road surfaces through a four-channel tire-coupled road simulator.

[0041] Step 6: Place the vehicle prototype in a low-temperature environment chamber, set the ambient temperature to -30℃, and let it stand for 12 hours. Then, evaluate the abnormal noise of the powertrain suspension under the start-stop condition and record the score Fts.

[0042] Step 7: Place the complete vehicle prototype on a four-channel tire-coupled road simulator, set the ambient temperature to -30℃, and let it stand for 12 hours. Excite the vehicle on the four-channel tire-coupled road simulator using the vibration road spectrum T to evaluate the abnormal noise of the powertrain mounting. Record the scores Ft1, Ft2, Ft3...Fti for various bad road surfaces.

[0043] Step 8: For the ignition shutdown condition, Ps represents its usage frequency. For the bad road pass test, Pai represents the usage frequency of various bad road surfaces. The usage frequency of the bad road pass test surfaces is shown in Table 2.

[0044] Table 2. Road surface usage frequency for the bad road pass test.

[0045] Serial Number bad road surface Pai usage frequency 1 dilapidated road 0.3 2 Arched uneven road 0.1 3 Corner Railway 0.3 4 Small round protrusion 0.3 5 cement road 1 6 washboard road 0.1 7 cobblestone 0.1 8 Belgium 0.3 9 Fish Scale Pit 0.3 10 Twisted Stairs 0.1 11 Large round protrusion 0.1 12 Twisted Road 1 13 Smooth Road 1 14 dilapidated roads around the city 0.3

[0046] Step 9: Calculate the suspension noise score under vehicle driving conditions: Sr = Frs * Ps + ∑Fri * Pai; calculate the suspension noise score under low temperature test conditions: St = Fts * Ps + ∑Fti * Pai; and calculate the suspension noise score: S = Sr + St.

[0047] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for evaluating abnormal noises in a powertrain mounting system, characterized in that, Includes the following steps: S1. Prepare powertrain mounting samples and vehicle samples, and install the mounting samples onto the vehicle samples; S2. Place the complete vehicle prototype on a flat surface and evaluate the powertrain mounting noise under start-stop conditions, recording the score Frs; S3. Place the vehicle at the test track and conduct a rough road test. Simultaneously evaluate the abnormal noise of the powertrain mounting and record the scores Fr1, Fr2, Fr3...Fri for various rough road surfaces. S4. Drive the prototype vehicle through various rough road surfaces at the required speed and collect the vibration acceleration D of the wheel steering knuckles; S5. The vibration acceleration D of the wheel steering knuckle is used to obtain the vibration spectrum T of the whole vehicle passing through various bad road surfaces through a four-channel tire-coupled road simulator. S6. Place the complete vehicle prototype in a low-temperature environment chamber to evaluate the abnormal noise of the powertrain mounting under the start-stop condition and record the score Fts; S7. Place the complete vehicle prototype on a four-channel tire-coupled road simulator, stimulate the vehicle on the four-channel tire-coupled road simulator, evaluate the abnormal noise of the powertrain mounting, and record the scores Ft1, Ft2, Ft3...Fti when passing through various bad road surfaces; S8. For the ignition-shutdown condition, Ps represents its usage frequency; for the bad road pass test, Pai represents the usage frequency of various bad road surfaces. S9. Calculate the suspension noise score under vehicle driving conditions: Sr = Frs * Ps + ∑Fri * Pai; Calculate the suspension noise score under low temperature test conditions: St = Fts * Ps + ∑Fti * Pai; Calculate the suspension noise score: S = Sr + St.

2. The method for evaluating abnormal noises in a powertrain mounting system as described in claim 1, characterized in that, In step S1, the suspended prototype must meet the design requirements for structure, size and stiffness; the prototype vehicle must have the ability to drive in low temperature and on rough roads.

3. The method for evaluating abnormal noises in a powertrain mounting system as described in claim 1, characterized in that, In step S1, the suspension sample is installed on the vehicle prototype, requiring an installation torque Q ≥ 100 Nm.

4. The method for evaluating abnormal noises in a powertrain mounting system as described in claim 1, characterized in that, In step S3, a bad road driving test is conducted to require the vehicle to pass through various bad road surfaces at required speeds. The road surface and speed requirements for the bad road driving test are as follows:

5. The method for evaluating abnormal noises in a powertrain mounting system as described in claim 1, characterized in that, In step S4, a vibration acceleration sensor is installed at the wheel steering knuckle and connected to a vibration noise data acquisition system to collect the vibration acceleration D of the wheel steering knuckle.

6. The method for evaluating abnormal noises in a powertrain mounting system as described in claim 1, characterized in that, In step S6, the ambient temperature is set to -30℃, and the system is left to stand for 12 hours before evaluating the abnormal noise of the powertrain mounting under ignition-shutdown conditions.

7. The method for evaluating abnormal noises in a powertrain mounting system as described in claim 1, characterized in that, In step S7, the ambient temperature is set to -30℃, and the vehicle is left to stand for 12 hours. The entire vehicle is then stimulated using a four-channel tire-coupled road simulator via vibration road spectrum T to evaluate powertrain mounting noise.

8. The method for evaluating abnormal noises in a powertrain mounting system as described in claim 1, characterized in that, In step S8, the frequency of road surface use during the bad road test is as follows: 。

Images