A method for formulating eol test limit value of auto parts

Abstract

The invention discloses a method for setting the EOL test limit value of auto parts, which comprises the following steps: installing the parts to be tested on the whole vehicle, and selecting detection points in the whole vehicle; using noise and vibration testing equipment, passing the hammer test , to obtain the frequency response function of vibration and sound transmission from the installation point of the component on the vehicle to the detection point in the vehicle, take dB as its coordinate for the response value, and draw the VTNTF function curve; find the maximum value and minimum value of the VTNTF function curve The difference is divided into M equal parts, and then the points on the VTNTF function curve are divided into M equal parts, and the response values ​​of the points on the VTNTF function curve are weighted according to the interval, and then the VTNTF curve is normalized, that is, VTNTF‑RE / max , denoted as VTNTF‑RE‑F; select critically acceptable parts on the vehicle to retest on EOL, and perform Fourier transform to obtain its frequency domain curve, and multiply the frequency domain curve by VTNTF‑ The weighted calculation is performed on the RE-F curve to obtain the limit value curve in the entire frequency spectrum. The present invention comprehensively and comprehensively formulates the EOL limit value for the entire perceivable sound frequency range.

Description

technical field [0001] The invention belongs to the technical field of off-line detection methods for auto parts, and more specifically relates to a method for formulating EOL test limits for auto parts. Background technique [0002] The auto parts EOL testing machine is mainly used for the quality inspection of key auto parts (such as engines, gearboxes, gearboxes, motors, etc.) Fixed evaluation limits (need to be approved by customers) are used as indicators to evaluate whether they are qualified or not, but the performance of key auto parts installed on the vehicle has a strong correlation with the structure, strength, and acoustic scheme of the vehicle , but the EOL test evaluation limit does not take these influences into account. The traditional EOL limit cannot comprehensively consider the performance of the part in the whole vehicle's perceivable sound frequency range (20-2000Hz), so it is impossible to formulate a comprehensive and comprehensive limit. , It is easy...

AI Technical Summary

Problems solved by technology

[0002] The auto parts EOL testing machine is mainly used for the quality inspection of key auto parts (such as engines, gearboxes, gearboxes, motors, etc.) Fixed evaluation limits (need to be approved by customers) are used as indicators to evaluate whether they are qualified or not, but the performance of key auto parts installed on the vehicle has a strong correlation with the structure, strength, and acoustic scheme of the vehicle , but the EOL test evaluation limit does not take these influences into account. The traditional EOL limit cannot comprehensively consider the performance of the part in the whole vehicle's perceivable sound frequency range (20-2000Hz), so it is impossible to formulate a comprehensive and comprehensive limit. , it is easy to cause some uncritical frequency bands to be too strict, affecting the production qualification rate of parts, and the key frequency bands are relatively loose, so the correlation between the test value of parts on EOL and the whole vehicle is relatively poor

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