A kind of silencing apparatus of multistage composite noise reduction
Technical field
The utility model relates to a kind of silencing apparatus, specifically a kind of silencing apparatus of multistage composite noise reduction.
Background technique
Silencing apparatus is to stop sound transmission and a kind of device of allowing air-flow to pass through, is the important measures of eliminating air power noise.Be arranged on engine exhaust port and fall low noise device.
Existing diesel engine silencer is comprised of inlet duct joint, one-level amplification silencing cavity, outlet pipe (identical with inlet duct diameter).
Existing diesel engine silencer has following some shortcomings:
1, diesel combustion, work done process are rough, amplify silencing cavity soundproof effect poor by the one-level of diesel engine.Send noise and the high-decibel value thereof of " jump, jump, jump " and make us endurable, so traffic control department regulation is furnished with the agricultural transportation vehicle, tractor, hand tractor etc. of diesel engine and is forbidden to go down town.
2, the driver who drives for a long time agricultural transportation vehicle, tractor, hand tractor etc. is also because noise factor feels that body and mind is tired standby.
3, existing diesel engine silencer adopts oxy-acetylene welding technique, and making quality is coarse, and profile is also attractive in appearance not, and productivity is also relatively low simultaneously.
In view of above-mentioned defect, be in fact necessary to design a kind of soundproof effect good, make quality attractive in appearance, productivity is higher silencing apparatus also.
Model utility content
It is good that the utility model aims to provide a kind of soundproof effect, and making quality is attractive in appearance, and productivity is the silencing apparatus of the compound noise reduction of more much higher level also.
For solving the problems of the technologies described above, the technical solution of the utility model is:
A kind of silencing apparatus of multistage composite noise reduction, comprise pipe joint, silencer cover, lower shell body, upper shell, silencing net, outlet pipe and sound absorbing material, described pipe joint is connected to the exhaust elbow that cylinder covers, described silencer cover is connected with described pipe joint respectively with described lower shell body, on described silencer cover sidewall, there is aperture, described lower shell body is connected with described upper shell, described silencing net is fixed between described upper shell and described lower shell body, described upper shell is positioned at the top of described silencing net, described lower shell body is positioned at the below of described silencing net, described silencing net convex surface is to described silencer cover direction, the aperture that has high density to arrange on described silencing net, described outlet pipe is connected with the mouth of pipe necking down of described upper shell, described sound absorbing material is positioned at described lower shell body, in the inwall of described upper shell and described outlet pipe.
Described silencer cover inner chamber forms the first silencing cavity, the space of described lower shell body and described silencing net forms the second silencing cavity, the space of described silencing net and described upper shell forms the 3rd silencing cavity, and the mouth of pipe necking down of described upper shell forms the 4th silencing cavity to the space of described outlet pipe; Ventilation net cross-sectional area is followed successively by described the 4th silencing cavity, described the 3rd silencing cavity, described the second silencing cavity, described the first silencing cavity from big to small, and the ventilation net cross-sectional area of wherein said the first silencing cavity is greater than the ventilation net cross-sectional area of described pipe joint internal channel.
Hole diameter on described silencer cover sidewall is 3-5mm further, and the hole diameter on described silencing net is 1-2mm.
Described sound absorbing material is high temperature resistant sound absorbing material further.
Described silencer cover is riveted on described pipe joint further.
Described upper shell is riveted on described lower shell body further.
Adopt technique scheme, the utility model at least comprises following beneficial effect:
The silencing apparatus of multistage composite noise reduction described in the utility model, the level Four silencing cavity of amplifying step by step by ventilation net cross-sectional area is set, large and small hole replaces silencer cover and the silencing net of noise reduction, and the sound absorbing material of compound noise reduction, can make noise decline 20-25 decibel, the other noise of ear, by becoming roughly soft, obviously reduces high, medium and low audible sound composition in audible spectrum, thereby has reduced people's interference and injury.
Accompanying drawing explanation
Fig. 1 is the structural drawing of the silencing apparatus of a kind of multistage composite noise reduction described in the utility model.
Wherein: 1. pipe joint, 2. silencer cover, 3. lower shell body, 4. upper shell, 5. silencing net, 6. outlet pipe, 7. sound absorbing material, 8. the first silencing cavity, 9. the second silencing cavity, 10. the 3rd silencing cavity, 11. the 4th silencing cavity.
Embodiment
Below in conjunction with drawings and Examples, the utility model is further illustrated.
As shown in Figure 1, for meeting the silencing apparatus of a kind of multistage composite noise reduction of the present embodiment, comprise pipe joint 1, silencer cover 2, lower shell body 3, upper shell 4, silencing net 5, outlet pipe 6 and sound absorbing material 7, described pipe joint 1 is connected to the exhaust elbow that cylinder covers, described silencer cover 2 is connected with described pipe joint 1 respectively with described lower shell body 3, on described silencer cover 2 sidewalls, there is aperture, described lower shell body 3 is connected with described upper shell 4, described silencing net 5 is fixed between described upper shell 4 and described lower shell body 3, described upper shell 4 is positioned at the top of described silencing net 5, described lower shell body 3 is positioned at the below of described silencing net 5, described silencing net 5 convex surfaces are to described silencer cover 2 directions, the aperture that has high density to arrange on described silencing net 5, described outlet pipe 6 is connected with the mouth of pipe necking down of described upper shell 4, described sound absorbing material 7 is positioned at described lower shell body 3, in the inwall of described upper shell 4 and described outlet pipe 6.
Described silencer cover 2 inner chambers form the first silencing cavity 8, described lower shell body 3 forms the second silencing cavity 9 with the space of described silencing net 5, described silencing net 5 forms the 3rd silencing cavity 10 with the space of described upper shell 4, and the mouth of pipe necking down of described upper shell 4 forms the 4th silencing cavity 11 to the space of described outlet pipe 6; Ventilation net cross-sectional area is followed successively by described the 4th silencing cavity 11, described the 3rd silencing cavity 10, described the second silencing cavity 9, described the first silencing cavity 8 from big to small, and the ventilation net cross-sectional area of wherein said the first silencing cavity 8 is greater than the ventilation net cross-sectional area of described pipe joint 1 internal channel.
The noise elimination mechanism of the present embodiment combines the principle of resistive noise reduction, resistant noise-reducing, microperforated panel noise reduction, aperture noise reduction and porous material composite sound-absorbing, by variety of way is compound, realizes noise reduction.Well-known described resistive noise reduction is to utilize sound wave to propagate in porous sound-absorbing material or sound absorption structure, because friction is converted into heat energy by acoustic energy, dissipates, and makes to decay with distance along the noise of pipe transmmision, can well absorb medium-high frequency sound.Described resistant noise-reducing is in propagation of sound process, to cause that by sudden change place of pipeline section or the other resonant cavity etc. of connecing the change of impedance produces the reflection of acoustic energy, interference, thereby reduces by silencing apparatus to extraradial acoustic energy, and centering effect of low-frequency sound absorption is remarkable.
The silencing apparatus of the multistage composite noise reduction described in the present embodiment, the level Four silencing cavity of amplifying step by step by ventilation net cross-sectional area is set, large and small hole replaces silencer cover 2 and the silencing net 5 of noise reduction, and the sound absorbing material 7 of compound noise reduction, perfectly combine various noise reduction modes, can make noise decline 20-25 decibel, the other noise of ear is by becoming roughly soft, high, medium and low audible sound composition in audible spectrum is obviously reduced, thereby reduced people's interference and injury.
Preferably the hole diameter on described silencer cover 2 sidewalls is 3-5mm, and the hole diameter on described silencing net 5 is 1-2mm.Select the chamber that different punching rates is different with thickness of slab dark, just can control the spectral performance of silencing apparatus, make it in the frequency range of needs, obtain good soundproof effect.The selection of above-mentioned data is intended to the explanation of doing for the present embodiment can fully implement, and those skilled in the art completely can revise accordingly and set according to actual user demand.
Preferably described sound absorbing material 7 is high temperature resistant sound absorbing material 7.Described high temperature resistant sound absorbing material 7 is bonded on the inwall of described lower shell body 3, described upper shell 4 and described outlet pipe 6 by resistant to elevated temperatures metal adhesive.Described resistant to elevated temperatures metal adhesive can resistance to 1500 ℃ of even higher temperature, described high temperature resistant sound absorbing material 7 can 1260 ℃ of heatproofs or more than.Because need to coordinating motor, uses by the baffler described in the present embodiment, well-known described motor can produce very high temperature in use, reasonably select high temperature resistant sound absorbing material 7 and the resistant to elevated temperatures metal adhesive can be so that the usability of whole baffler is better, longer service life.Those skilled in the art should know, the explanation that the selection of sound absorbing material 7 described above is just carried out for the present embodiment can fully implement, and any other apparent conversion and replacement are all within the protection domain of the present embodiment.
Preferably described silencer cover 2 is riveted on described pipe joint 1, and described upper shell 4 is riveted on described lower shell body 3.Preferably the pipe joint 1 of described silencing apparatus is provided with screw thread, is connected on the exhaust elbow in the cylinder head of described motor.The above-mentioned mode by riveted joint connects and can, so that replace original oxy-acetylene welding technique in preparation process, can boost productivity accordingly.But those skilled in the art should know, do not limit above-mentioned Placement herein, any Placement that can make it to connect is all within the protection domain of the present embodiment.
Above embodiment of the present utility model is had been described in detail, but the preferred embodiment that described content is only created for the utility model can not be considered to the practical range of creating for limiting the utility model.All equalization variations of doing according to the utility model creation application range and improvement etc., within all should still belonging to patent covering scope of the present utility model.