JP2000276180A5 - - Google Patents

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Publication number
JP2000276180A5
JP2000276180A5 JP1999080778A JP8077899A JP2000276180A5 JP 2000276180 A5 JP2000276180 A5 JP 2000276180A5 JP 1999080778 A JP1999080778 A JP 1999080778A JP 8077899 A JP8077899 A JP 8077899A JP 2000276180 A5 JP2000276180 A5 JP 2000276180A5
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JP
Japan
Prior art keywords
slit
expansion portion
speaker
drive signal
frequency
Prior art date
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Granted
Application number
JP1999080778A
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Japanese (ja)
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JP4195751B2 (en
JP2000276180A (en
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Publication date
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Priority to JP08077899A priority Critical patent/JP4195751B2/en
Priority claimed from JP08077899A external-priority patent/JP4195751B2/en
Publication of JP2000276180A publication Critical patent/JP2000276180A/en
Publication of JP2000276180A5 publication Critical patent/JP2000276180A5/ja
Application granted granted Critical
Publication of JP4195751B2 publication Critical patent/JP4195751B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Description

この実体形態における冷却ファン１１は、回転数が２８８０／ｍｉｎで、翼枚数が５枚である。したがって、上記正弦波の周波数は（２８８０／６０）×５＝２４０Ｈｚとなる。
信号処理部９０は、上記正弦波の周波数を有したスピーカ駆動信号を生成し、この駆動信号を増幅器１０を介してスピーカ６に供給する。もちろん、この駆動信号の位相および振幅は、スピーカ６から送出される音波が冷却ファン１１の発生音波を打消すように調整される。 The cooling fan 11 in this physical form has a rotation speed of 2880 / min and a number of blades of 5. Therefore, the frequency of the sine wave is (2880/60) × 5 = 240 Hz.
The signal processing unit 90 generates a speaker drive signal having the frequency of the sine wave, and supplies the drive signal to the speaker 6 via the amplifier 10. Of course, the phase and amplitude of this drive signal are adjusted so that the sound wave transmitted from the speaker 6 cancels the sound wave generated by the cooling fan 11.

図１、図３および図４に示した消音装置では、円形のスリット状膨張部４を設けているが、これに代えて、図９に示すように楕円形のスリット状膨張部４０を設けても良い。このスリット状膨張部４０は、短径部分と長径部分で深さが相違するので、２種の周波数域の音波に適応することができる。なお、更に多数の周波数域の音波に適応し得るような形状をスリット状膨張部４に持たせることも可能である。 In the silencer shown in FIGS. 1, 3 and 4, a circular slit-shaped expansion portion 4 is provided, but instead, an elliptical slit-shaped expansion portion 40 is provided as shown in FIG. Is also good. Slit-like expansion portion 40 of this, since the depth short diameter portion and a long diameter portion is different, it is possible to adapt the sound wave of the two frequency ranges. It is also possible to give the slit-shaped expansion portion 4 a shape that can be adapted to sound waves in a larger number of frequency ranges.

JP08077899A 1999-03-25 1999-03-25 Silencer Expired - Fee Related JP4195751B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP08077899A JP4195751B2 (en) 1999-03-25 1999-03-25 Silencer

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP08077899A JP4195751B2 (en) 1999-03-25 1999-03-25 Silencer

Publications (3)

Publication Number Publication Date
JP2000276180A JP2000276180A (en) 2000-10-06
JP2000276180A5 true JP2000276180A5 (en) 2006-03-09
JP4195751B2 JP4195751B2 (en) 2008-12-10

Family

ID=13727911

Family Applications (1)

Application Number Title Priority Date Filing Date
JP08077899A Expired - Fee Related JP4195751B2 (en) 1999-03-25 1999-03-25 Silencer

Country Status (1)

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JP (1) JP4195751B2 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4690735B2 (en) * 2005-01-31 2011-06-01 国立大学法人横浜国立大学 Fan noise reduction device and fan noise reduction method
JP7413327B2 (en) 2021-09-07 2024-01-15 株式会社東芝 Sound generator and blade noise reduction device

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