An experimental method for predicting the sound quality of the blowing noise of a vehicle air conditioner

Abstract

The present invention relates to a test method for predicting the sound quality of the whole vehicle air conditioner blowing noise, which comprises the following steps: calculating the transfer function from the HVAC assembly bench noise of the existing platform vehicle model to the whole vehicle air conditioner blowing noise; testing the HVAC assembly bench noise of the newly developed vehicle model based on the existing platform and calculating the sound quality of the whole vehicle air conditioner blowing noise of the newly developed vehicle model according to the transfer function. If it is found through the prediction results that the sound quality of the whole vehicle air conditioner blowing noise is poor and cannot meet the set development target, the relevant system can be optimized in advance until the target requirements are met, which can greatly save the later actual prototype vehicle adjustment cycle and the design change cost generated by the adjustment.

Description

Technical Field

[0001] The present invention relates to the field of automotive NVH improvement, and particularly to a method for predicting the sound quality of the whole vehicle air-conditioning blowing noise of a new vehicle model. Background Art

[0002] Before the present invention, there was no application of the same or similar method to predict the sound quality of the whole vehicle air-conditioning blowing noise.

[0003] As a modern means of transportation, automobiles have entered thousands of households and become an increasingly common means of transportation. With the improvement of people's living standards, an automobile is no longer a simple means of transportation. People's attention has gradually shifted from its functions to its quality, especially the comfort quality. The whole vehicle vibration noise is a comfort performance that customers can truly feel, and the air-conditioning system noise, as an important performance in the whole vehicle vibration noise, has also received more and more attention from customers. Especially in new energy vehicle models, due to the lack of a large masking noise source of the engine, the air-conditioning blowing noise becomes more prominent and has also become a major problem for customer complaints, often ranking among the top 10 in the JDPOWER IQS complaints. Therefore, reducing the whole vehicle air-conditioning blowing noise has become a very important task in the development of automotive vibration noise.

[0004] There are many methods for optimizing the whole vehicle air-conditioning blowing noise. At the source, it can be achieved by optimizing the blower motor, blade design, air door design, etc. On the path, it is usually achieved by optimizing the air duct, grille, instrument panel, etc. In terms of control, the voltage can be reduced, and then the rotational speed of the blower can be reduced to achieve the purpose of noise reduction.

[0005] Although there are many methods for reducing the whole vehicle air-conditioning blowing noise, most of them can only be carried out after the prototype vehicle comes out. Moreover, due to limitations in layout, cost, cycle, and other performances, it is often impossible to improve. Even if improvements are made, it will increase the cost and cycle. If the whole vehicle air-conditioning noise level can be predicted before the prototype vehicle comes out in the initial stage of project development, the design can be optimized in advance, which can greatly reduce the later development cycle and design cost. Therefore, based on this idea, the present invention provides a test method that can predict the sound quality of the whole vehicle air-conditioning noise. Summary of the Invention

[0006] In order to solve the problems existing in the prior art, the present invention provides a test method for predicting the sound quality of the whole vehicle air conditioning blowing noise. The method calculates the transfer function from the HVAC system bench noise to the whole vehicle noise through the whole vehicle blowing noise data of the existing platform model and the HVAC system bench noise data. Then, for the newly developed model on this platform model, before the prototype vehicle is released, after the HVAC assembly (including the air duct) has a sample, the HVAC system assembly bench noise is tested. Finally, the sound quality of the whole vehicle air conditioning blowing noise of the new model is predicted through the HVAC system bench noise sound quality of the new model and the transfer function of the existing platform model. Therefore, the optimized design can be carried out according to the predicted noise sound quality, which greatly reduces the later development cycle and development cost.

[0007] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0008] A test method for predicting the sound quality of air-conditioning blowing noise of a whole vehicle comprises the following steps:

[0009] 1) Calculate the transfer function from the HVAC assembly bench noise to the whole vehicle air conditioning blowing noise of the existing platform model;

[0010] 2) Test the HVAC assembly bench noise of a newly developed vehicle model based on the existing platform and, based on the transfer function obtained in step 1), deduce the sound quality of the air conditioning blowing noise of the newly developed vehicle model.

[0011] Step 1) The transfer function calculation method comprises the following steps:

[0012] 1a) Test the whole vehicle air conditioning blowing noise of the existing platform model and process the data into the whole vehicle air conditioning blowing noise frequency curve of the existing platform model;

[0013] 1b) Test the HVAC assembly bench noise of the existing platform vehicle model and process the data into the HVAC assembly bench noise frequency curve of the existing platform vehicle model;

[0014] 1c) Subtract the frequency range curve of the HVAC assembly bench noise of the existing platform model obtained in step 1b) from the frequency range curve of the air conditioning blowing noise of the existing platform model obtained in step 1a) to obtain the transfer function from the HVAC assembly bench noise of the existing platform model to the air conditioning blowing noise of the whole vehicle.

[0015] The method for calculating the sound quality of the whole vehicle air conditioning blowing noise of the newly developed model in step 2) is: the measured HVAC assembly bench noise of the newly developed model is processed into the HVAC assembly bench noise frequency range curve of the newly developed model, and then the HVAC assembly bench noise frequency range curve of the newly developed model is added to the transfer function to obtain the whole vehicle air conditioning blowing noise frequency range curve of the newly developed model.

[0016] The test method for the blowing noise of the vehicle air conditioner of the existing platform models in step 1a) is as follows: Test the noise under the maximum air volume condition in three modes, namely the coldest inner circulation of the oncoming wind, the hottest outer circulation of the foot blowing wind, and the hottest outer circulation of the defrosting wind.

[0017] The test conditions for testing the blowing noise of the vehicle air conditioner of the existing platform models in step 1a) are consistent with those for testing the HVAC assembly bench noise of the existing platform models in step 1b).

[0018] The test method for the HVAC assembly bench noise of the existing platform models in step 1b) is to remove the HVAC assembly from the vehicle, then build a bench, and test the noise under the boundary conditions simulating the vehicle.

[0019] The said boundary conditions include: The coordinates of the sound measurement points are consistent with those of the vehicle; There should be a backpressure device at the outer circulation air inlet; There should be a reflection device around the HVAC; The components such as air ducts and grilles are consistent with those of the vehicle.

[0020] Before removing the HVAC assembly from the vehicle, first test the blowing noise of the vehicle air conditioner.

[0021] The test method for the HVAC assembly bench noise of the newly developed models in step 2) is as follows: Before the newly developed models come out, after there are prototype parts of the HVAC assembly, build an HVAC bench and conduct the HVAC assembly bench noise test.

[0022] The said frequency range curve is a 1 / 3 octave frequency range curve, and the analysis frequency range is 50 Hz to 10,000 Hz.

[0023] The beneficial effects of the present invention are as follows:

[0024] Through the test method described in the present invention, in the initial stage of project development (when the actual prototype vehicle has not come out), through the HVAC system bench noise and the transfer function from the bench to the vehicle, the sound quality of the blowing noise of the vehicle air conditioner of the newly developed models can be predicted. If it is found through the prediction results that the sound quality of the blowing noise of the vehicle air conditioner is poor and does not meet the set development goals, relevant systems can be optimized in advance until the target requirements are met, which can greatly save the calibration cycle of the actual prototype vehicle in the later stage and the design change costs generated by calibration. Description of the Drawings

[0025] The following further describes the present invention with reference to the drawings.

[0026] Figure 1 It is a 1 / 3 octave frequency range curve graph of the blowing noise of the vehicle air conditioner of the existing models;

[0027] Figure 2 It is a 1 / 3 octave frequency range curve graph of the HVAC assembly bench noise of the existing models;

[0028] Figure 3 is the transfer function from the HVAC assembly bench noise of the existing vehicle model to the vehicle air conditioner blowing noise;

[0029] Figure 4 is the 1 / 3 octave band curve of the HVAC assembly bench noise of the newly developed vehicle model;

[0030] Figure 5 is the sound quality prediction curve of the vehicle air conditioner blowing noise of the newly developed vehicle model;

[0031] Figure 6 is the flow chart of the test method described in the present invention. Detailed implementation manners

[0032] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation to the present invention.

[0033] Embodiment 1

[0034] The embodiment of the present invention provides a test method for predicting the sound quality of the vehicle air conditioner blowing noise, as Figure 6 shown, including the following steps:

[0035] 1) Calculate the transfer function from the HVAC assembly bench noise of the existing platform vehicle model to the vehicle air conditioner blowing noise;

[0036] 2) Test the HVAC assembly bench noise of the newly developed vehicle model based on the existing platform and calculate the sound quality of the vehicle air conditioner blowing noise of the newly developed vehicle model according to the transfer function obtained in step 1).

[0037] In this embodiment, both the HVAC assembly bench noise and the vehicle air conditioner blowing noise are represented by 1 / 3 octave band curves, and the analysis frequency range is 50 Hz to 10,000 Hz.

[0038] Specifically, the calculation method of the transfer function in step 1) includes the following steps:

[0039] 1a) Test the vehicle air conditioner blowing noise of the existing platform vehicle model and process the data into the 1 / 3 octave band curve of the vehicle air conditioner blowing noise of the existing platform vehicle model, as Figure 1 shown;

[0040] Among them, the test method of the vehicle air conditioner blowing noise of the existing platform vehicle model is usually to test the noise under the maximum air volume condition in three modes, and the three modes are: ① Head-on wind, coldest, inner circulation; ② Foot blowing wind, hottest, outer circulation; ③ Defrosting wind, hottest, outer circulation. In the vehicle air conditioner noise test, the requirements for instruments, measuring points, test settings, etc. are implemented according to the enterprise's test standards.

[0041] 1b) Test the HVAC assembly bench noise of the existing platform models and process the data into the 1 / 3 octave band frequency curves of the HVAC assembly bench noise of the existing platform models, as Figure 2 shown;

[0042] The method for testing the HVAC assembly bench noise of the existing platform models is as follows: Remove the HVAC system on the vehicle to build the bench, and then simulate the boundary conditions of the vehicle for testing. The HVAC system bench must include the following boundaries: ① The coordinates of the sound measurement points are the same as those of the vehicle; ② There should be a backpressure device at the fresh air inlet of the outside air circulation; ③ There should be a reflection device around the HVAC, such as the front windshield, firewall, floor, etc.; ④ The components such as air ducts and grilles are the same as those of the vehicle. In addition, in order to eliminate the differences of the HVAC, usually first test the air outlet noise data of the vehicle air conditioner, and then remove the HVAC system on the vehicle to build the bench.

[0043] When testing the HVAC assembly bench noise of the existing platform models, the test conditions are the same as those of the vehicle test.

[0044] 1c) Subtract the 1 / 3 octave band frequency curve of the HVAC assembly bench noise of the existing platform models obtained in step 1b) from the 1 / 3 octave band frequency curve of the vehicle air conditioner blowing noise of the existing platform models obtained in 1a) to obtain the transfer function from the HVAC assembly bench noise to the vehicle air conditioner blowing noise of the existing platform models, as Figure 3 shown.

[0045] In step 2), the test method for testing the HVAC assembly bench noise of the newly developed models based on the existing platform is as follows: Before the newly developed models come out, after there are prototype parts of the HVAC assembly, build the HVAC bench and conduct the HVAC assembly bench noise test.

[0046] The calculation method for the sound quality of the vehicle air conditioner blowing noise of the newly developed models is as follows: Process the measured HVAC assembly bench noise of the newly developed models into the 1 / 3 octave band frequency curve of the HVAC assembly bench noise of the newly developed models, as Figure 4 shown, and then add the 1 / 3 octave band frequency curve of the HVAC assembly bench noise of the newly developed models to the transfer function to obtain the 1 / 3 octave band frequency curve of the vehicle air conditioner blowing noise of the newly developed models, as Figure 5 shown.

[0047] Through the obtained 1 / 3 octave band frequency curve of the vehicle air conditioner blowing noise of the newly developed models, the sound quality of the vehicle air conditioner blowing noise of the newly developed models can be predicted. If it is found through the prediction results that the sound quality of the vehicle air conditioner blowing noise is poor and does not meet the set development goals, the relevant systems can be optimized in advance until the target requirements are met. This can greatly save the calibration cycle of the actual prototype vehicle in the later stage and the design change costs generated by the calibration.

[0048] The above specific implementation manners describe the basic principles and main features of the present invention. Those skilled in the art should understand that the protection scope of the present invention is not limited by the above embodiments, and any changes or substitutions that can be conceived without creative efforts should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope defined by the claims.

Claims

1. An experimental method for predicting the sound quality of the blowing noise of a vehicle air conditioner, characterized in that , including the following steps: 1) Calculate the transfer function from the HVAC assembly bench noise to the whole vehicle air conditioning blowing noise of the existing platform model; 2) Test the HVAC assembly bench noise of a newly developed vehicle model based on the existing platform and, based on the transfer function obtained in step 1), deduce the sound quality of the whole vehicle air conditioning blowing noise of the newly developed vehicle model; in: Step 1) The transfer function calculation method comprises the following steps: 1a) Test the whole vehicle air conditioning blowing noise of the existing platform model and process the data into the whole vehicle air conditioning blowing noise frequency curve of the existing platform model; 1b) Test the HVAC assembly bench noise of the existing platform vehicle model and process the data into the HVAC assembly bench noise frequency curve of the existing platform vehicle model; 1c) Subtracting the frequency range curve of the HVAC assembly bench noise of the existing platform model obtained in step 1b) from the frequency range curve of the air conditioning blowing noise of the existing platform model obtained in step 1a) to obtain a transfer function from the HVAC assembly bench noise of the existing platform model to the air conditioning blowing noise of the whole vehicle; The method for calculating the sound quality of the whole vehicle air conditioning blowing noise of the newly developed model in step 2) is: the measured HVAC assembly bench noise of the newly developed model is processed into the HVAC assembly bench noise frequency range curve of the newly developed model, and then the HVAC assembly bench noise frequency range curve of the newly developed model is added to the transfer function to obtain the whole vehicle air conditioning blowing noise frequency range curve of the newly developed model.

2. The test method for predicting the sound quality of the blowing noise of a vehicle air conditioner according to claim 1, characterized in that The test method for the whole vehicle air conditioning blowing noise of the existing platform model in step 1a) is: testing the noise of the maximum air volume condition under three modes, the three modes are the coldest internal circulation of headwind, the hottest external circulation of footwind and the hottest external circulation of defrost wind.

3. The test method for predicting the sound quality of the blowing noise of the vehicle air conditioner according to claim 1, wherein The test conditions for testing the whole vehicle air conditioning blowing noise of the existing platform model in step 1a) are consistent with the test conditions for testing the HVAC assembly bench noise of the existing platform model in step 1b).

4. The test method for predicting the sound quality of the blowing noise of a vehicle air conditioner according to claim 1, characterized in that, In step 1b), the test method for the bench noise of the HVAC assembly of the existing platform vehicle model is to remove the HVAC assembly from the whole vehicle, then build a bench, and test the noise under boundary conditions simulating the whole vehicle.

5. The test method for predicting the sound quality of the blowing noise of a vehicle air conditioner according to claim 4, characterized in that, The boundary conditions include: the coordinates of the sound measurement point are consistent with the entire vehicle; there must be a back pressure device at the external circulation air inlet; there must be a reflection device around the HVAC; the air duct and grille components are consistent with the entire vehicle.

6. The test method for predicting the sound quality of the blowing noise of a vehicle air conditioner according to claim 4, characterized in that Before removing the HVAC assembly from the vehicle, test the air conditioning noise of the vehicle.

7. The test method for predicting the sound quality of the blowing noise of the vehicle air conditioner according to claim 1, characterized in that In step 2), the test method for the HVAC assembly bench noise of the newly developed model is: before the newly developed model is released, after the HVAC assembly has samples, build an HVAC bench and carry out the HVAC assembly bench noise test.

8. A test method for predicting the sound quality of the blowing noise of a vehicle air conditioner according to any one of claims 1-7, characterized in that, The frequency curve is a 1 / 3 octave curve, and the analysis frequency range is 50 Hz to 10000 Hz.

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