Noise optimization test method for mechanical oil pump of automobile automatic transmission

Abstract

The invention discloses an automobile automatic transmission mechanical oil pump noise optimization testing method, and belongs to the technical field of automobile NVH testing. The method comprises: calculating the working order of a mechanical oil pump; the related structure and working condition information of the automatic transmission are confirmed, and working conditions related to NVH performance are analyzed; making a test project plan; testing according to the test project plan and the field test result; based on the test data, the noise contribution frequency of the mechanical oil pump is analyzed, noise generation reasons are analyzed in combination with the characteristics of the noise contribution frequency, a noise optimization scheme is made, and a noise optimization verification sample piece is manufactured; and according to the requirement on the NVH performance of the mechanical oil pump, repeating until the NVH performance of the mechanical oil pump meets the requirement or cannot be further optimized. According to the invention, accurate capture of correlation between fluid dynamic characteristics and noise of the oil duct under extreme oil supply flow and high-pressure working conditions is realized, and the problem of large deviation between a traditional test means and a real working condition is solved.

Description

Technical Field

[0001] This invention relates to a method for optimizing the noise of a mechanical oil pump in an automotive automatic transmission, belonging to the field of automotive NVH testing technology. Background Technology

[0002] The mechanical oil pump in an automatic transmission serves as the core hydraulic source of the drivetrain, providing both working oil pressure to the clutch and lubrication and cooling flow to the system. Under harsh operating conditions with high oil flow and high system pressure, the hydraulic fluid within the oil passages is prone to turbulence, flow disturbances, and cavitation, leading to abnormal noise during the operation of the mechanical oil pump. This noise issue directly affects the vehicle's ride quality, causing user complaints about the overall NVH performance of the vehicle. Summary of the Invention

[0003] To address the problems existing in the background art, the present invention provides a method for optimizing the noise of a mechanical oil pump in an automotive automatic transmission.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a method for optimizing the noise of a mechanical oil pump in an automotive automatic transmission, the method comprising the following steps: S1: Calculate the operating order of the mechanical oil pump; S2: Confirm the relevant structure and operating condition information of the automatic transmission, and analyze its operating conditions related to NVH performance; S3: Based on the information collected in S1 and S2, develop a test project plan map; S4: Conduct tests according to the established test plan and on-site test results; S5: Based on the test data, analyze the noise contribution frequency of the mechanical oil pump, analyze the causes of noise generation in combination with the characteristics of the noise contribution frequency, and formulate a noise optimization plan. S6: Implement the noise optimization scheme and produce a noise optimization verification prototype; S7: Based on the requirements for the NVH performance of the mechanical oil pump, repeat S4-S5 until the NVH performance of the mechanical oil pump meets the requirements or cannot be further optimized.

[0005] Furthermore, step S1 includes the following steps: S101: Confirm the relevant structural information of the mechanical oil pump installed in the target model under test, including: the number of teeth A of the mechanical oil pump drive teeth, the number of teeth B of the mechanical oil pump driven teeth, and the order R2 of the mechanical oil pump rotor. S102: Calculate the speed ratio R1=A / B between the pump shaft speed of the mechanical oil pump and the input speed of the drive source; S103: Calculate the operating order of the mechanical oil pump R=R1×R2, and the harmonic harmonic frequency iR of the mechanical oil pump, where i=1,2,3,……,n, and n is the harmonic harmonic multiple.

[0006] Furthermore, the relevant structure and operating condition information mentioned in S2 includes: the gear information and corresponding speed range of the automatic transmission, the commonly used working oil pressure range of the automatic transmission and the current value of the relevant oil circuit control solenoid valve in the corresponding valve body, and the working status of the hydraulic torque converter of the automatic transmission and the status of the corresponding solenoid valve.

[0007] Furthermore, step S4 includes the following steps: S401: Select either mechanical oil pump unit bench test or automatic transmission unit unit bench test; S402: Install a sound acquisition device at a distance of 0.5m from the mechanical oil pump; S403: Acquire A-weighted sound pressure level or sound power through a sound acquisition device; S404: During the testing process, the test project plan map is revised and optimized based on the feedback from on-site test results.

[0008] Furthermore, the process of analyzing test data described in S5 includes: For transient test data, use any one of the following analysis methods: acoustic diagnostics, interpolation method, or masking effect. For steady-state test data, any one of the following analysis methods is used: characteristic frequency filtering, envelope analysis, Hilbert transform, or fast Fourier transform.

[0009] Furthermore, the means of implementing the noise optimization scheme described in S6 include tooth profile modification, optimization of transmission fluid performance, optimization of shift lines, optimization of control oil pressure, and optimization of torque converter direct connection timing.

[0010] Compared with the prior art, the beneficial effects of the present invention are: This invention calculates the operating order and harmonic characteristics of the mechanical oil pump, and formulates a test plan based on the actual operating parameters of the automatic transmission. This achieves precise capture of the correlation between the fluid dynamics characteristics of the oil passage and noise under extreme oil supply flow and high pressure conditions. Using single-unit or full-machine bench testing, combined with optimized acoustic acquisition equipment and multi-dimensional data analysis methods, the invention systematically simulates the noise radiation characteristics of the mechanical oil pump under actual vehicle conditions, solving the problem of large deviations between traditional testing methods and real operating conditions. Through low-cost and high-efficiency improvement measures such as gear profile modification and oil performance optimization, combined with simulation models and industry experience, the invention reduces the cost of verifying optimization schemes while ensuring improved NVH performance. Finally, through a cyclic testing verification mechanism, the invention ensures that the noise optimization results of the mechanical oil pump meet customer requirements and industry standards, significantly improving vehicle driving quality. Attached Figure Description

[0011] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0012] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0013] A method for optimizing the noise of a mechanical oil pump in an automotive automatic transmission, the method comprising the following steps: S1: Calculate the operating order of the mechanical oil pump; S2: Confirm the relevant structure and operating condition information of the automatic transmission, and analyze its operating conditions related to NVH performance; S3: Based on the information collected in S1 and S2, develop a test project plan map; Based on the automatic transmission gear information and corresponding speed range, common operating oil pressure range and corresponding main oil pressure solenoid valve current value, torque converter operating status and corresponding SLU control solenoid valve status collected by S2, S3 uses a combination of gear condition + speed range + main oil pressure + torque converter status to match test conditions, specifically including the following steps: S301: Transient operating conditions (including acceleration and deceleration conditions): Neutral, reverse, and gears 1-6 correspond to turbo input speeds of 750 rpm to 5500 rpm; 7th gear corresponds to turbo input speeds from 1000rpm to 4000rpm; 8th gear corresponds to turbo input speeds from 1000rpm to 3000rpm; S302: Steady-state operating condition: The first gear corresponds to engine speeds of 750 rpm, 2000 rpm, 3000 rpm, 4000 rpm, and 5000 rpm. Gears 2-5 correspond to engine speeds of 1000rpm, 2000rpm, 3000rpm, 4000rpm, 5000rpm, and 5500rpm, respectively. The 6 gears correspond to engine speeds of 000rpm, 2000rpm, 3000rpm, 4000rpm, and 5000rpm. The 7th gear corresponds to engine speeds of 1000rpm, 2000rpm, 3000rpm, and 4000rpm; 8 gears correspond to engine speeds of 1000rpm, 2000rpm, and 3000rpm; Reverse gear corresponds to engine speeds of 750 rpm, 1000 rpm, and 2000 rpm; Neutral gear corresponds to RPMs of 750rpm, 2000rpm, 3000rpm, and 4000rpm.

[0014] S4: Conduct tests according to the established test plan and on-site test results; S5: Based on the test data, analyze the noise contribution frequency of the mechanical oil pump, analyze the causes of noise generation in combination with the characteristics of the noise contribution frequency, and formulate a noise optimization plan. S6: Implement the noise optimization scheme and produce a noise optimization verification prototype; S7: Based on the requirements for the NVH performance of the mechanical oil pump, repeat S4-S5 until the NVH performance of the mechanical oil pump meets the requirements or cannot be further optimized.

[0015] Furthermore, step S1 includes the following steps: S101: Confirm the relevant structural information of the mechanical oil pump of the target model under test, including: the number of teeth A of the mechanical oil pump drive teeth, the number of teeth B of the mechanical oil pump driven teeth, and the order R2 of the mechanical oil pump rotor (corresponding to the number of meshing teeth in the oil pump rotor). S102: Calculate the speed ratio R1=A / B between the pump shaft speed of the mechanical oil pump and the input speed of the drive source; S103: Calculate the operating order of the mechanical oil pump, R = R1 × R2, and the harmonic harmonic frequency iR, where i = 1, 2, 3, ..., n, and n is the harmonic harmonic multiple. Preferably, n = 10, meaning that focusing on the first 10 harmonics of the mechanical oil pump is sufficient to meet its NVH performance optimization evaluation requirements.

[0016] Furthermore, the relevant structure and operating condition information mentioned in S2 includes: the gear information and corresponding speed range of the automatic transmission, the commonly used working oil pressure range of the automatic transmission and the current value of the relevant oil circuit control solenoid valve in the corresponding valve body, and the working status of the hydraulic torque converter of the automatic transmission and the status of the corresponding solenoid valve.

[0017] The gears include 8 forward gears, 1 reverse gear, 1 neutral gear, and 1 parking gear; The oil circuit control solenoid valve is the main oil pressure solenoid valve, with a control current of 0.2A and 0.4A, which realizes two-level adjustment of the main oil circuit pressure, high and low. The hydraulic torque converter is equipped with a direct-drive oil circuit SLU control solenoid valve, whose operating states include non-direct-drive state (control current 0A), intermediate state (control current 0.6A), and direct-drive state (control current 1A).

[0018] Furthermore, step S4 includes the following steps: S401: Select either a mechanical oil pump unit bench test or an automatic transmission unit unit bench test to simulate the actual flow field working state of the mechanical oil pump. S402: Install a sound acquisition device at a distance of 0.5m from the mechanical oil pump; S403: Acquire A-weighted sound pressure level or sound power through a sound acquisition device; S404: During the testing process, the test project plan map is corrected and optimized based on the feedback from on-site test results, so as to achieve comprehensive, accurate and efficient data test collection.

[0019] Furthermore, the process of analyzing test data described in S5 includes: For transient test data, use any one of the following analysis methods: acoustic diagnostics, interpolation method, or masking effect. For steady-state test data, any one of the following analysis methods is used: characteristic frequency filtering, envelope analysis, Hilbert transform, or fast Fourier transform.

[0020] The key orders analyzed include the pump drive order R1, the pump operating order R, and the harmonic frequencies 2R, 4R, 5R, and 6R.

[0021] Furthermore, the means of implementing the noise optimization scheme described in S6 include tooth profile modification, optimization of transmission fluid performance, optimization of shift lines, optimization of control oil pressure, and optimization of torque converter direct connection timing.

[0022] When implementing optimization plans and producing verification prototypes, the implementation cost and verification cycle of the optimization plan should be comprehensively considered, taking into account simulation model calculation results, industry experience, and other factors.

[0023] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of the equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0024] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for optimizing the noise of a mechanical oil pump in an automotive automatic transmission, characterized in that: The method includes the following steps: S1: Calculate the operating order of the mechanical oil pump; S2: Confirm the relevant structure and operating condition information of the automatic transmission, and analyze its operating conditions related to NVH performance; S3: Based on the information collected in S1 and S2, develop a test project plan map; S4: Conduct tests according to the established test plan and on-site test results; S5: Based on the test data, analyze the noise contribution frequency of the mechanical oil pump, analyze the causes of noise generation in combination with the characteristics of the noise contribution frequency, and formulate a noise optimization plan. S6: Implement the noise optimization scheme and produce a noise optimization verification prototype; S7: Based on the requirements for the NVH performance of the mechanical oil pump, repeat S4-S5 until the NVH performance of the mechanical oil pump meets the requirements or cannot be further optimized.

2. The method for optimizing the noise of an automatic transmission hydraulic pump in an automobile according to claim 1, characterized in that: S1 includes the following steps: S101: Confirm the relevant structural information of the mechanical oil pump installed in the target model under test, including: the number of teeth A of the mechanical oil pump drive teeth, the number of teeth B of the mechanical oil pump driven teeth, and the order R2 of the mechanical oil pump rotor. S102: Calculate the speed ratio R1=A / B between the pump shaft speed of the mechanical oil pump and the input speed of the drive source; S103: Calculate the operating order of the mechanical oil pump R=R1×R2, and the harmonic harmonic frequency iR of the mechanical oil pump, where i=1,2,3,……,n, and n is the harmonic harmonic multiple.

3. The method for optimizing the noise of an automatic transmission hydraulic pump in an automobile according to claim 2, characterized in that: The relevant structure and operating condition information mentioned in S2 includes: the gear information and corresponding speed range of the automatic transmission, the commonly used working oil pressure range of the automatic transmission and the current value of the relevant oil circuit control solenoid valve in the corresponding valve body, as well as the working status of the hydraulic torque converter of the automatic transmission and the status of the corresponding solenoid valve.

4. The method for optimizing the noise of an automatic transmission hydraulic pump in an automobile according to claim 3, characterized in that: S4 includes the following steps: S401: Select either mechanical oil pump unit bench test or automatic transmission unit unit bench test; S402: Install a sound acquisition device at a distance of 0.5m from the mechanical oil pump; S403: Acquire A-weighted sound pressure level or sound power through a sound acquisition device; S404: During the testing process, the test project plan map is revised and optimized based on the feedback from on-site test results.

5. The method for optimizing the noise of an automotive automatic transmission mechanical oil pump according to claim 1, characterized in that: The analysis process of the test data described in S5 includes: For transient test data, use any one of the following analysis methods: acoustic diagnostics, interpolation method, or masking effect. For steady-state test data, any one of the following analysis methods is used: characteristic frequency filtering, envelope analysis, Hilbert transform, or fast Fourier transform.

6. The method for optimizing the noise of an automotive automatic transmission mechanical oil pump according to claim 5, characterized in that: The means of implementing the noise optimization scheme described in S6 include tooth profile modification, optimization of transmission fluid performance, optimization of shift lines, optimization of control oil pressure, and optimization of torque converter direct connection timing.

Images