A kind of automotive muffler of controlling reproduced air-flow noise
Technical field
The utility model relates to automotive silencing technology, is specifically related to a kind of automotive muffler of controlling reproduced air-flow noise.
Background technique
Along with the raising to environmental requirement, the restriction increasingly stringent to automobile noise in the environmental legislation of countries in the world.In order to adapt to domestic and international automobile market with keen competition and social sustainable development demand, require the design producer of automobile not affect the power character of motor, on the basis of Economy, reduce the noise level of automobile as far as possible excessive.Along with internal-combustion engine develops to speed up, automobile noise problem has become the major issue of the solution of having to.Exhaust sound is topmost noise source in vehicle noise.
Automotive muffler is the air exhaust muffler device that Hyundai Motor extensively adopts, and is the simple and effective means that reduce engine noise.The noise when quality of the actual acoustic attenuation performance of silencing apparatus is directly connected to car load work is big or small, concerns the noise level of car load.
Affecting the most important factor of exhaust sound is engine speed and load, and its reason is that rotating speed increase increases airspeed in exhaust duct.High velocity air produces regenerated noise main cause two kinds.Be that inner-walls of duct or other members produce vibration and a radiated noise under air-flow percussion, this kind is construct noise.Another kind is during due to complicated structure by silencing apparatus shell of the exhaust airstream of high engine speeds, can run into the situations such as the abrupt change of cross-section, perforated plate, perforated pipe, elbow, and high velocity air causes noise by the strong turbulent motion of generation, and this kind is turbulence noise.Along with the increase of airspeed, at the inner regenerated noise producing of silencing apparatus, also increase.
Regenerated noise has an immense impact on to the performance of silencing apparatus, and the actual soundproof effect of silencing apparatus is sharply declined, and when regenerated noise can make silencing apparatus greatly to a certain extent, loses soundproof effect, when serious, even can make silencing apparatus become noise amplifier.
Along with power of vehicle increases, internal-combustion engine develops to speed up, the reproduced air-flow noise problem of silencing apparatus becomes the key factor that affects Sound Elimination Performance of Mufflers.Therefore, the high-performing car silencing apparatus of reproduced air-flow noise is controlled in development, for reduction automobile noise, minimizing urban environment noise, pollutes and has great importance.
Model utility content
The purpose of this utility model is a kind of automotive muffler of controlling reproduced air-flow noise of design, silencing apparatus inner chamber is divided into three chambers, suction tude, steam outlet pipe and transition tube space arrange, discharges after air-flow is slowed down in compand repeatedly, effectively reduces reproduced air-flow noise.
A kind of automotive muffler of controlling reproduced air-flow noise of the utility model design, comprises housing, suction tude and steam outlet pipe, and described suction tude enters housing, the inlet end that the import of suction tude is this silencing apparatus through housing front cover; The rear end cover of described steam outlet pipe by housing, pass silencing apparatus, the exhaust end that the outlet of steam outlet pipe is this silencing apparatus; In housing, be provided with housing shaft to vertical the first dividing plate and second partition, enclosure interior is isolated into the first expansion chamber, dissipative muffler chamber and three chambers of the second expansion chamber successively; Described suction tude and steam outlet pipe and housing shaft be to be arrangeding in parallel, also have transition tube also parallel with suction tude, steam outlet pipe, and space is arranged in housing.Described suction tude, through after the front cover of housing, through first, second dividing plate, stretches into the second expansion chamber successively, and the outlet end of suction tude is positioned at the second expansion chamber; Described steam outlet pipe one end is positioned at the first expansion chamber, and steam outlet pipe is successively through first and second dividing plate, then through the rear end cover of housing, pass silencing apparatus; One end of transition tube is positioned at the first expansion chamber, stretches into the second expansion chamber successively through after first and second dividing plate, and the other end of transition tube is positioned at the second expansion chamber.The part that described steam outlet pipe and transition tube are positioned at resistance noise reduction chamber is provided with micropore on tube wall; The part that described steam outlet pipe is positioned at the second expansion chamber is provided with micropore on tube wall.
The outlet end of described suction tude is extension mouth structure.Described extension mouth structure is round speaker mouth structure or oval extension mouth structure or rectangle extension mouth structure.And tube wall bending place is that fillet seamlessly transits.
For control structure noise, described suppressor case inwall, front cover and rear end cover inwall are all covered with the acoustical cotton of thick 10mm~30mm; The tube wall that described steam outlet pipe is positioned at the second expansion chamber is covered with the acoustical cotton of thick 10mm~30mm outward.
Described the first expansion chamber, dissipative muffler chamber and the axial length of the second expansion chamber are compared, the axial length of the second expansion chamber is greater than the axial length of the first expansion chamber, also be greater than the axial length of resistance noise reduction chamber, the axial length of the first expansion chamber is greater than the axial length of resistance noise reduction chamber.The ratio of the axial length of described the first expansion chamber, dissipative muffler chamber and the second expansion chamber is (2~4) ︰ (1~3) ︰ (4~6).
Micropore size on the tube wall of described transition tube and steam outlet pipe is 2~5mm.
Described steam outlet pipe and transition tube are positioned at the part of resistance noise reduction chamber, and on tube wall, percent opening is 15~20%; Described steam outlet pipe is positioned at the part of the second expansion chamber, and on tube wall, percent opening is 15~20%.The caliber of described suction tude, transition tube and steam outlet pipe is identical.
During the work of the utility model automotive muffler, air-flow enters suction tude and is retracted, from suction tude outlet end, discharge at the second expansion chamber intramedullary expansion, entering transition tube shrinks again, through transition tube, entering the first expansion chamber expands again, enter in steam outlet pipe and be retracted again, from steam outlet pipe, discharge this silencing apparatus.Because being positioned on the part tube wall of resistance noise reduction chamber, described transition tube has micropore, enter the compressed air stream in transition tube, can the micropore from its tube wall entering resistance noise reduction chamber expands, air-flow in resistance noise reduction chamber can enter steam outlet pipe through the micropore of steam outlet pipe tube wall, directly discharge or enter the second expansion chamber, air-flow in resistance noise reduction chamber also can return to transition tube through the micropore of transition tube wall, then enters the first expansion chamber or the second expansion chamber.Air-flow in the second expansion chamber, except entering transition tube, also can enter steam outlet pipe through the micropore of steam outlet pipe tube wall, directly discharges, or returns to the first expansion chamber through steam outlet pipe, then or enter resistance noise reduction chamber through the micropore of steam outlet pipe tube wall.The speed of the expansion of this silencing apparatus by repeatedly, contraction, air-flow reduces greatly, simultaneously by the aperture of pipeline and the absorption of the sound-absorbing material of inwall to high frequency radiation noise in silencing apparatus, thereby reproduced air-flow noise is reduced widely.
Compared with prior art, the automotive muffler that the utility model is controlled reproduced air-flow noise has the following advantages: the air-flow that 1, enters this silencing apparatus repeatedly compresses and expands through suction tude, transition tube and steam outlet pipe and three chambers arranged side by side, air-flow is transition more smoothly, exhaust velocity progressively reduces, and has reduced significantly reproduced air-flow noise; 2, suppressor case inwall, front cover and rear end cover inwall and steam outlet pipe rear-most end part are all covered with certain thickness acoustical cotton, control silencing apparatus Surface Radiation Noise, reduce construct noise; 3, the outlet of suction tude in the second expansion chamber is expansion bell-mouth structure of air, and tube wall takes round-corner transition, and exhaust airstream is more smoothly expanded reduction of speed, reduces reproduced air-flow noise; 4, simple in structure, easy to process, noise reduction is obvious, is applicable to the car combustion engine of various models.
Accompanying drawing explanation
The automotive muffler example structure schematic diagram that Fig. 1 is this control reproduced air-flow noise.
Number in the figure is:
1, the first expansion chamber, 2, suction tude, 21, suction tude outlet end, 3, housing, the 4, second expansion control chamber, 5, rear end cover, 6, steam outlet pipe, 7, transition tube, 8, second partition, 9, resistance noise reduction chamber, 10, micropore, the 11, first dividing plate, acoustical cotton, 13, front cover
In figure, arrow represents air-flow principal direction.
Embodiment
Below in conjunction with the drawings and specific embodiments, the utility model is described in further details:
Referring to Fig. 1, in the automotive muffler housing 3 of this control reproduced air-flow noise, be provided with and housing 3 axial vertical the first dividing plate 11 and second partition 8, housing 3 inside are isolated into the first expansion chamber 1, dissipative muffler chamber 9 and 4 three chambers of the second expansion chamber successively; The ratio of the axial length of this example the first expansion chamber 1, dissipative muffler chamber 9 and the second expansion chamber 4 is 3 ︰ 2 ︰ 5.
Described suction tude 2, transition tube 7 and steam outlet pipe 6 are arranged in housing 3 with housing 3 parallel to an axiss space.This routine suction tude 2, transition tube 7 are identical with steam outlet pipe 6 calibers.The import of described suction tude 2 is the inlet end of this silencing apparatus; Described suction tude 2 is through after the front cover 13 of housing 3, through the first dividing plate 11, second partition 8, stretch into the second expansion chamber 4 successively, the outlet end 21 of this routine suction tude 2 is round speaker mouth structure, tube wall bending place is that fillet seamlessly transits, and is positioned at the second expansion chamber 4.The outlet of described steam outlet pipe 6 is the exhaust end of this silencing apparatus; The entrance point of described steam outlet pipe 6 is positioned at the first expansion chamber 1, and steam outlet pipe 6 is successively through the first dividing plate 11 and second partition 8, then through the rear end cover 5 of housing 3, pass silencing apparatus; One end of transition tube 7 is positioned at the first expansion chamber 7, through the first dividing plate 11, second partition 8, stretches into the second expansion chamber 4 successively, and the other end of transition tube 7 is positioned at the second expansion chamber 4.The part that described steam outlet pipe 6 and transition tube 7 are positioned at resistance noise reduction chamber 9 is provided with the micropore 10 that aperture is 3mm on tube wall, and percent opening is 20%; The part that this routine steam outlet pipe 6 is positioned at the second expansion chamber 4 is provided with the micropore 10 that aperture is 3mm on tube wall, and percent opening is 20%.At the inwall of suppressor case 3, front cover 13 and rear end cover 5, be covered with the acoustical cotton 12 of thick 20mm, steam outlet pipe 6 is positioned at the acoustical cotton 12 that is also covered with thick 20mm on the tube wall of part of the second expansion chamber 4.
Contrast test, the car combustion engine of employing equal-wattage, installs the automotive muffler of the present embodiment and common silencing apparatus is installed, noise reduction reaches 1dB(A) more than.Noise reduction obviously improves.
Above-described embodiment, is only the specific case that the purpose of this utility model, technological scheme and beneficial effect are further described, and the utility model is not defined in this.All any modifications of making, be equal to replacement, improvement etc., within being all included in protection domain of the present utility model within scope of disclosure of the present utility model.