CN104457970A - Semi-anechoic box for wide frequency bandwidth measurement - Google Patents
Semi-anechoic box for wide frequency bandwidth measurement Download PDFInfo
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- CN104457970A CN104457970A CN201410673803.3A CN201410673803A CN104457970A CN 104457970 A CN104457970 A CN 104457970A CN 201410673803 A CN201410673803 A CN 201410673803A CN 104457970 A CN104457970 A CN 104457970A
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- broadband measurement
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Abstract
A semi-anechoic box for wide frequency bandwidth measurement comprises a barrel-shaped box body, a measurement microphone is arranged at the center of the box body, sound absorption materials or sound absorption structures are arranged on the inner walls of all faces, except the face where an object to be measured is installed, of the box body, the space standoff distances between the microphone and the surfaces of the sound absorption materials or the sound absorption structures are more than 20 cm, the space standoff distances are related to the minimum measuring frequency for measuring, and the lower the minimum measuring frequency is, the larger the space standoff distances are. The cross section of the interior of the barrel-shaped box body is polygonal, and the cross section of an outer box body is rectangular. According to the barrel-shaped box body, space occupied by sound insulation and absorption materials is small, no special large-size test chamber is needed, use convenience is achieved, large-scale product quality detection is facilitated, and production test cost is lowered; the sound insulation and absorption materials are firmly installed, and test operations are easy and convenient; because the sound insulation property is good, a measuring device is less disturbed by the outside, and accordingly test precision is high, test data repeatability is good and the semi-anechoic box can be used in different environments.
Description
One, technical field
The present invention relates to a kind of broadband measurement half silencer box, or perhaps the noise-abatement equipment of approximate semianechoic room measurement effect.
Two, background technology
The microphone device such as loudspeaker, mobile phone, its acoustical behavior, as frequency response, total harmonic distortion etc., requires to measure under free field (anechoic room) or semi-free field (semianechoic room) condition.But anechoic room or semianechoic room volume is large, cost is high, particularly inconvenient operation on a production line.So a kind of broadband measurement half silencer box simulating anechoic room or semianechoic room measurement effect becomes the only selection of industry, within the scope of the survey frequency of regulation, reach the effect of approximate anechoic room or semianechoic room measurement.
When prior art simulation anechoic room or semianechoic room are measured, especially the acoustical behavior in low-frequency range such as loudspeaker, mobile phone is measured, as low frequency reaches the silencer box structure that 100Hz (even 75Hz, 50Hz) has acoustic absorbants such as adopting wedge glass wool to prepare, but need the casing of 3 meters or more large scale, this can be equal to the volume of an anechoic room completely, and cost is high.And practicality is extremely difficult aborning, do not meet the designing requirement (production operation personnel are extremely inconvenient in use) of ergonomic yet.Current many communication products, photovoltaic, household appliances, electronic product etc. all can adopt this type of silencer box to carry out acoustics or noise test, as manufacturing enterprises such as computing machine, mobile phone, motor, power supplys.Silencer box product is mainly used in: the walkaway of computing machine and annex and quality control, the acoustical testing of communication products, electro-acoustic product, small-sized fans, scientific research.Existing silencer box specification feature: (1) inner sound absorption: acoustical absorption coefficient α >0.9 during >250Hz; (2) free space: design according to consumer products feature; (3) product structure: clad sheet steel sound insulating structure, dull and stereotyped sound absorber; (4) measuring system: microphone is fixed in case, and surveying instrument is selected; (5) noise objective: ensure at external noise lower than noise <26dBA in case during 75dBA.
CN201310424311 proposes a kind of silencer box, comprises sound-proof wall body and sound arrester, and described sound arrester comprises acoustical cotton and sound-absorbing cloth, and described acoustical cotton is evenly arranged on the inner side of described sound-proof wall body, acoustical cotton described in described sound-absorbing Bu Baoxiang.But the acoustically effective of sound-absorbing Bu Baoxiang acoustical cotton far can not be comparable with anechoic room.
CN200620172780. characteristic measuring device of sound insulation, the sound insulation property being mainly used in light sound-insulation material is measured.Include silencer box and reverberation box, silencer box lower ending opening, reverberation box upper end open, reverberation box and silencer box make to connect as one for two casees by the joint of upper and lower end opening, between silencer box and reverberation box, be provided with dividing plate; The tank wall of described silencer box is MULTILAYER COMPOSITE sound absorption structure, and the tank wall of described reverberation box is MULTILAYER COMPOSITE damping structure, and silencer box has doorframe, and doorframe place is provided with soundproof door.
CN201310407449 discloses a kind of sound suppressor, comprises upper wall, lower wall, Zuo Bi and You Bi, and wherein upper wall and lower wall are separately installed with multiple upper anechoic sheet and multiple lower anechoic sheet, and Zuo Bi and right wall arrange air inlet and air outlet respectively.Described multiple upper anechoic sheet and multiple lower anechoic sheet are crisscross arranged mutually arrangement on the left and right directions and above-below direction of sound suppressor.
CN201220355858 discloses a kind of handset audio device for quick testing, and it comprises support portion, compressed part and test department.Described support portion is used for holding mobile telephone.Described compressed part is arranged on the side of described support portion and comprises fast ram pressure to compress mobile phone.Described test department comprises artificial mouth and artitificial ear, and the microphone of mobile phone aimed at by described artificial mouth, and the loudspeaker of mobile phone aimed at by described artitificial ear.By arranging support portion, compressed part and test department to realize carrying out the mobile phone on production line the quick test of audio performance.Due to the restriction in space, do not have condition to build and use the semianechoic room close to desirable free field, may just need to set up a sound insulation environment close to a small volume of free field is need most and practical pursuit.
Three, summary of the invention
The present invention seeks to, propose a kind of silencer box, especially a kind of broadband measurement half silencer box, internal background noise is low to make it reach under the test environment, and provides the approximate Half free sound field space of cutoff frequency 100Hz (even lower).Thus the accuracy of measurement and repeatable and measuring speed can be guaranteed.Certainly, there is small size and meet ergonomic service condition better.
Technical scheme of the present invention is, a kind of broadband measurement half silencer box, comprises tubular casing; It is characterized in that casing central authorities arrange measuring microphone support, acoustic absorbant or sound absorption structure is arranged at the inwall of all of casing except installing the upper cover plate of object to be measured (as loudspeaker, mobile phone etc.), the space standoff distance making the surface of microphone and acoustic absorbant or sound absorption structure is more than 20cm, space standoff distance is relevant with the minimum survey frequency of measurement, minimum survey frequency is lower, and space standoff distance is larger.
Further, the xsect of tubular box house is polygon, and the xsect of tubular casing outside is rectangle;
Further, the acoustic absorbant being arranged in wall can be arranged as concavo-convex alternate structure, and the concavo-convex cycle is (2 ~ 10) cm;
Further, bottom the cylinder of cylinder inner core height less than about 1/4, position surrounding arranges diffusion sound absorption composite structure, and diffusion sound absorption composite structure is arranged in 1/3 perimeter locations of surrounding at least in more than about 1/4 position of cylinder height.The finished surface of diffusion sound absorption composite structure becomes (130 ° ~ 170 °) angle with interior;
Further, barrel and tube end plate have porous plate, absorbent treatment, acoustic damping layer and outer sound insulating layer;
Further, cover plate installs and measures loudspeaker, cover plate tilts, horizontal by (10 °-35 °) angle.Cover plate arranges fixing and hold down gag, to ensure object to be measured (as loudspeaker, mobile phone etc.) impermeability after installation is complete.
Beneficial effect of the present invention is: casing comprises sound insulation and acoustic absorbant takes up space little, without the need to the special test cabinet that volume is larger, easy to use, facilitates large-scale product quality to detect, reduces production test cost; Sound insulation and acoustic absorbant are installed firmly, and test operation is easy; Because sound insulation property is good, measurement mechanism is little by external interference degree, and therefore measuring accuracy is high, and test data is reproducible, and can use in multiple different environment.Silencer box of the present invention can supply the acoustic measurement of Microspeaker and complete machine (as mobile phone, panel computer, notebook computer), comprises other loudspeaker and microphone acoustic measurement; The present invention can simulate the enough low background environment of background noise, and provides the approximate Half free sound field space of cutoff frequency 100Hz (even lower).Thus the accuracy of measurement and repeatable and measuring speed can be guaranteed.The configuration design had more meets ergonomic.Diffusion sound absorption composite structure can produce repeatedly refraction or the diffraction of noiseless impact on noise, thus has cut down noise content; To loudspeaker audio device for quick testing, save the time, improve production efficiency.
Four, accompanying drawing explanation
Fig. 1 is structural representation of the present invention.
Five, embodiment
As shown in the figure, spread sound absorption composite structure 1, the second diffusion of cylinder lower floor absorbs sound composite structure 2, test upper cover plate 3, divide baffle mounting hole 4, microphone arm 5, outer sound insulating layer 6, damping and absorbent treatment 7, resonance sound-absorbing layer 8, internal layer acoustic absorbant 9, isolation mounting or universal wheel 10.
A kind of broadband measurement half silencer box, comprises tubular casing; Wherein casing central authorities arrange measuring microphone support, acoustic absorbant or sound absorption structure is arranged at the inwall of all of casing except installing the face of object to be measured (as loudspeaker, mobile phone etc.), the space standoff distance making the surface of microphone and acoustic absorbant or sound absorption structure is more than 20cm, space standoff distance is relevant with the minimum survey frequency of measurement, minimum survey frequency is lower, and space standoff distance is larger.Microphone arm 5 installs and measures microphone, and position, in the position of central upper, ensures that noise background is herein low, can ignore the negative effect of measuring.
The xsect of tubular box house is polygon, and especially the xsect of tubular casing outside is rectangle, is originally embodied as rectangle, especially square; The the second diffusion sound absorption composite structure 2 forming diffusion sound absorption composite structure 1, cylinder lower floor arranged at least by acoustic absorbant at the wall of cylinder, described diffusion sound absorption composite structure is concavo-convex alternate structure, the concavo-convex cycle is (2 ~ 10) cm, especially (3 ~ 5) cm; Bottom the cylinder of cylinder inner core height less than about 1/4, position surrounding arranges diffusion sound absorption composite structure, and diffusion sound absorption composite structure is at least arranged in 1/3 perimeter locations of surrounding in more than about 1/4 position of cylinder height.
The finished surface of diffusion sound absorption composite structure becomes (130 ° ~ 170 °) angle with interior.Barrel and tube end plate have porous plate, absorbent treatment, acoustic damping layer and outer sound insulating layer.Cover plate is installed object to be measured (as loudspeaker, mobile phone etc.), cover plate tilts, and cover plate is horizontal by (10 ° ~ 35 °) angle, and corresponding barrel plate also so coordinates, and has two pieces of wallboards to be trapezoidal.Cover plate arranges fixing and hold down gag, to ensure object to be measured (as loudspeaker, mobile phone etc.) impermeability after installation is complete.Barrel plate outside plate adopts medium density fiberboard, clamping plate etc. to have the material of certain oise insulation factor and rigidity.Acoustic absorbant is arranged as concavo-convex alternate structure, better superimposed with bulk material.Barrel and tube end plate have porous plate, absorbent treatment, acoustic damping layer and outer sound insulating layer.Cover plate is installed object to be measured (as loudspeaker, mobile phone etc.), cover plate tilts, with surface level (ground) in 10-35 degree.
The fixed support of measuring microphone adopts hollow metal tube, and vertical with upper cover plate, be installed on base plate, measuring microphone band fastener is installed in metal tube, and its data line passes from hollow tubular.When survey frequency scope is to low frequency (minimum survey frequency) 100Hz, casing xsect is that rectangle is of a size of (80 ~ 120) cm* (80 ~ 120) cm; Box height is (70 ~ 110) cm, and wall thickness is (8-15) cm.When the lower limit of survey frequency scope is higher than 100Hz, the size of casing can be less.Namely the space in the space of microphone can reach more than 20cm good effect.100Hz, and when the xsect of chest is rectangle, rectangle is of a size of (80 ~ 120) cm* (80 ~ 120) cm; Box height is (70 ~ 110) cm, and wall thickness is (8 ~ 15) cm.
Cover plate arranges fixing and hold down gag, to ensure object to be measured (as loudspeaker, mobile phone etc.) impermeability after installation is complete.
Universal wheel (under traffic condition) is provided with or/and isolation mounting (under conditions of use can the vibrational energy of anti-outside enter) at the bottom of case.
Although the present invention with preferred embodiment disclose as above, so itself and be not used to limit the present invention.The technical field of the invention has knows the knowledgeable usually, without departing from the spirit and scope of the present invention, when doing various change and retouching.Therefore, protection scope of the present invention, when being as the criterion depending on those as defined in claim.
Claims (9)
1. broadband measurement half silencer box, comprises tubular casing; It is characterized in that casing central authorities arrange measuring microphone, acoustic absorbant or sound absorption structure is arranged at the inwall of all of casing except installing the face of object to be measured, the space standoff distance making the surface of microphone and acoustic absorbant or sound absorption structure is more than 20cm, space standoff distance is relevant with the minimum survey frequency of measurement, minimum survey frequency is lower, and space standoff distance is larger.
2. a kind of broadband measurement half silencer box according to claim 1, is characterized in that the xsect of tubular box house is polygon; Outer case xsect is rectangle.
3. a kind of broadband measurement half silencer box according to claim 1, is characterized in that arranging acoustic absorbant or sound absorption structure at the inwall of all of casing except installing the face of object to be measured; Acoustic absorbant is arranged as concavo-convex alternate structure, and the concavo-convex cycle is 2-10cm.
4. a kind of broadband measurement half silencer box according to claim 1, it is characterized in that position surrounding arranges diffusion sound absorption composite structure bottom the cylinder of case inner core height less than 1/4, diffusion sound absorption composite structure is at least arranged in 1/3 perimeter locations of surrounding in the position of case inner core height more than 1/4.
5. a kind of broadband measurement half silencer box according to claim 4, is characterized in that the finished surface of diffusion sound absorption composite structure and interior are 130 ° ~ 170 ° angles.
6., according to a kind of broadband measurement half silencer box one of claim 1-5 Suo Shu, it is characterized in that cabinet exterior and tube end plate have porous plate, absorbent treatment, acoustic damping layer and outer sound insulating layer; Cover plate is installed object to be measured, cover plate tilts, horizontal by 10-35 degree.
7. according to a kind of broadband measurement half silencer box one of claim 1-5 Suo Shu, it is characterized in that minimum survey frequency is 100Hz, and when the xsect of chest is rectangle, rectangle is of a size of 80 ~ 120 cm * 80 ~ 120cm; Box height is 70 ~ 110cm, and cabinet exterior thickness is 8 ~ 15cm.
8., according to a kind of broadband measurement half silencer box one of claim 1-5 Suo Shu, it is characterized in that cover plate arranges fixing and hold down gag, to ensure object to be measured impermeability after installation is complete.
9., according to a kind of broadband measurement half silencer box one of claim 1-5 Suo Shu, it is characterized in that being provided with isolation mounting at the bottom of case or/and universal wheel.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201410673803.3A CN104457970B (en) | 2014-11-21 | 2014-11-21 | A kind of half silencer box of broadband measurement |
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| CN201410673803.3A CN104457970B (en) | 2014-11-21 | 2014-11-21 | A kind of half silencer box of broadband measurement |
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| CN104457970A true CN104457970A (en) | 2015-03-25 |
| CN104457970B CN104457970B (en) | 2018-07-06 |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104713777A (en) * | 2013-12-11 | 2015-06-17 | 胡伟萍 | Tensile testing machine with safety guard and noise-proof function |
| CN107560722A (en) * | 2017-08-28 | 2018-01-09 | 华东交通大学 | The high-precision noise measuring method and noise contribution analysis method of a kind of box-beam structure |
| CN109286887A (en) * | 2018-09-20 | 2019-01-29 | 苏州岸肯电子科技有限公司 | Silencer box is used in a kind of test of loudspeaker |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5024290A (en) * | 1989-03-17 | 1991-06-18 | Lignoform Benken Ag | Sound absorbing panel for interior walls |
| CN200993649Y (en) * | 2006-12-30 | 2007-12-19 | 中国舰船研究设计中心 | Sound insulation performance measuring device |
| US20090084627A1 (en) * | 2005-09-08 | 2009-04-02 | Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel Ltd.) | Double wall structure |
| CN201708927U (en) * | 2010-06-25 | 2011-01-12 | 深圳市豪恩声学股份有限公司 | Sound insulation test case |
| CN103474057A (en) * | 2013-09-13 | 2013-12-25 | 苏州岸肯电子科技有限公司 | Silencing chamber |
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2014
- 2014-11-21 CN CN201410673803.3A patent/CN104457970B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5024290A (en) * | 1989-03-17 | 1991-06-18 | Lignoform Benken Ag | Sound absorbing panel for interior walls |
| US20090084627A1 (en) * | 2005-09-08 | 2009-04-02 | Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel Ltd.) | Double wall structure |
| CN200993649Y (en) * | 2006-12-30 | 2007-12-19 | 中国舰船研究设计中心 | Sound insulation performance measuring device |
| CN201708927U (en) * | 2010-06-25 | 2011-01-12 | 深圳市豪恩声学股份有限公司 | Sound insulation test case |
| CN103474057A (en) * | 2013-09-13 | 2013-12-25 | 苏州岸肯电子科技有限公司 | Silencing chamber |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104713777A (en) * | 2013-12-11 | 2015-06-17 | 胡伟萍 | Tensile testing machine with safety guard and noise-proof function |
| CN107560722A (en) * | 2017-08-28 | 2018-01-09 | 华东交通大学 | The high-precision noise measuring method and noise contribution analysis method of a kind of box-beam structure |
| CN109286887A (en) * | 2018-09-20 | 2019-01-29 | 苏州岸肯电子科技有限公司 | Silencer box is used in a kind of test of loudspeaker |
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| CN104457970B (en) | 2018-07-06 |
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