Fan noise and resonance measurement equipment

Abstract

The invention discloses a fan noise resonance measurement device, comprising a base, a fan fixing base, a resonance part, a resonance part fixing base and a vibration signal pickup and analysis device, wherein the fan fixing base and the resonance part fixing base are respectively mounted on the base ; There is an embedding groove for embedding the fan on the fan holder, and the fan outlet is upwardly embedded in the embedding groove; the lower end of the resonance member is inclined and fixed on the resonance member fixing base, and the upper end of the resonance member is obliquely fixed. It extends above the air outlet of the fan; the vibration signal pickup and analysis device is connected with the resonance part, and the vibration signal pickup and analysis device includes a vibration sensor and an analyzer connected with it to analyze and display the vibration signal. In this way, the fan noise signal is converted into a vibration signal, and the vibration amount is used to determine whether the fan is qualified. The device has low requirements for the test environment, good anti-interference, and high signal recognition.

Description

technical field [0001] The invention relates to the technology in the field of fan detection, in particular to a device for measuring abnormal noise and resonance of a fan. Background technique [0002] CPUs and graphics cards generally use fans to dissipate heat. Before entering the market, this type of fans must undergo noise testing to detect whether the fans have abnormal sounds. The noise of fans is generally divided into two categories: mechanical vibration noise and aerodynamic noise. The latter is also called aerodynamic noise, and aerodynamic noise is divided into broadband noise and narrow-band noise. The turbulent flow in the boundary layer is continuously formed, decays and swings along the flow direction, thereby generating a fluctuating pressure field, which is the turbulent sound source; the source of narrow-band noise: the air flow in the flow channel between the blades periodically hits the On the outer frame, ribs, and static guide vanes, noise of a fixed ...

AI Technical Summary

Problems solved by technology

[0002] CPUs and graphics cards generally use fans to dissipate heat. Before entering the market, this type of fans must undergo noise testing to detect whether the fans have abnormal sounds. The noise of fans is generally divided into two categories: mechanical vibration noise and aerodynamic noise. The latter is also called aerodynamic noise, and aerodynamic noise is divided into broadband noise and narrow-band noise. The turbulent flow in the boundary layer is continuously formed, decays and swings along the flow direction, thereby generating a fluctuating pressure field, which is the turbulent sound source; the source of narrow-band noise: the air flow in the flow channel between the blades periodically hits the On the outer frame, ribs, and static guide vanes, noise of a fixed tone is generated; when the airflow leaves the tail of the blade, a separate flow or vortex will be generated, and these vortices will generate periodic noise; at the fan inlet, the distribution of axial velocity is uneven, As the impeller turns, it creates (periodic) sudden pressure changes in the wingtip clearance; poor design or poor assembly can cause additional narrow-frequency hum

[0003] When the fan has the above-mentioned narrow-frequency abnormal sound, it is mostly a substandard product. The conventional method for detecting whether the fan has a narrow-frequency abnormal sound is as follows: directly test the noise spectrum and judge the abnormal sound through the noise spectrum. The advantage of this test method is that it is direct and effective. , the disadvantage is that the test noise must be measured in a professional anechoic room, and the tester needs to be professional enough to judge

The other is to test the noise spectrum and the vibration spectrum at the same time, and obtain a simple judgment through a series of complex algorithms. The advantage of this method is that the requirements for the professional level of the testers are reduced, but the requirements for the test environment are still high. And the whole test system and algorithm are more complex

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