CN204113411U - For the ridge-like structure perforated pipe muffling unit of reactive muffler - Google Patents

For the ridge-like structure perforated pipe muffling unit of reactive muffler Download PDF

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Publication number
CN204113411U
CN204113411U CN201420533228.2U CN201420533228U CN204113411U CN 204113411 U CN204113411 U CN 204113411U CN 201420533228 U CN201420533228 U CN 201420533228U CN 204113411 U CN204113411 U CN 204113411U
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China
Prior art keywords
ridge
perforated pipe
perforated
reactive muffler
muffling unit
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Expired - Fee Related
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CN201420533228.2U
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Chinese (zh)
Inventor
周以齐
李�瑞
米永振
白儒
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Shandong University
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Shandong University
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Abstract

The utility model discloses a kind of ridge-like structure perforated pipe muffling unit for reactive muffler, comprise a perforated pipe, it is characterized in that: along on the direction of air stream transportation in described perforated pipe, the perforation pipeline section being positioned at flow outlet direction is provided with the perforation of the low frequency acoustic attenuation performance for increasing perforated pipe, and the inwall being positioned at the perforated pipe in air flow inlet direction is provided with the ridge-like structure with property of reduction drag; First flow out from perforated section again through the combing of ridge-like structure during described airflow passes perforated pipe.The utility model utilizes the property of reduction drag of ridge-like structure to carry out combing air-flow, improves its aerodynamic performance.The utility model changes the uniform perforation of complete for conventional punch pipe section the uniform perforation of into pipeline section rear portion, increases the low frequency acoustic attenuation performance of perforated pipe.

Description

For the ridge-like structure perforated pipe muffling unit of reactive muffler
Technical field
The present invention relates to a kind of reactive muffler novel perforations pipe muffling unit structure, especially a kind of reactive muffler perforated pipe structure for engineering machinery.
Background technique
Reactive muffler is the main path of Control Engineering mechanical devolatilisation noise, and perforated pipe is one of muffling unit indispensable in reactive muffler, learn from the engineering machinery exhaust sound third-octave spectrum of actual measurement, mainly low-frequency range is concentrated on to the larger frequency band of exhaust sound contribution, therefore the control of low-frequency noise is the effective way reducing exhaust sound, because perforated pipe structure has the resonant frequency of its correspondence, ideal soundproof effect desirable near resonant frequency, therefore its resonant frequency of appropriate design, be located near low-frequency range and effectively can reduce low-frequency noise, and the pressure loss of perforated pipe is also less, therefore perforated pipe structure is widely used in reactive muffler.
From engineering machinery reactive muffler, manufacturer is recognized, even distribution type method for punching is generally adopted at present at industry middle punch pipe muffling unit, those skilled in the art also generally admit perforated section and are distributed in whole pipeline section and method as much as possible of boring a hole, perforated pipe low frequency acoustic attenuation performance can be played and the advantage such as the pressure loss is little because do like this, it is disorderly and unsystematic when but this mode can cause inner tube segment air-flow to flow through, speed fluctuation is violent, cause higher reproduced air-flow noise, affect the acoustic attenuation performance of silencing apparatus, in addition, owing to there is technology prejudice, those skilled in the art seldom can consider that the structure of position setting and the silencer internal wall of boring a hole is on the impact of soundproof effect.
Summary of the invention
The object of the invention is the technology prejudice for overcoming above-mentioned the deficiencies in the prior art and related domain, there is provided a kind of rational in infrastructure, acoustical behavior is good, reproduced air-flow noise is little, and the soundproof effect of, mid-frequency noise low to engine exhaust is significantly for the novel perforations pipe muffling unit of engineering machinery reactive muffler.
For achieving the above object, the present invention adopts following technical proposals:
For the ridge-like structure perforated pipe muffling unit of reactive muffler, comprise a perforated pipe, along on the direction of air stream transportation in described perforated pipe, the perforation pipeline section being positioned at flow outlet direction is provided with the perforation of the low frequency acoustic attenuation performance for increasing perforated pipe, and the inwall being positioned at the perforated pipe in air flow inlet direction is also provided with the ridge-like structure with property of reduction drag; First flow out from perforated section again through the combing of ridge-like structure during described airflow passes perforated pipe.Utilize the property of reduction drag of ridge-like structure to carry out combing air-flow, improve its aerodynamic performance.Change the uniform perforation of complete for conventional punch pipe section the uniform perforation of into pipeline section rear portion, increase the low frequency acoustic attenuation performance of perforated pipe.
Described ridge-like structure is trapezoidal ridge-like structure.
Described trapezoidal ridge-like structure directly processes on perforated pipe inwall, and it is depressed on perforated pipe inwall;
Described trapezoidal ridge-like structure is attached on perforated pipe inwall as parts, and it is overshooting shape.
Described ridge-like structure is in the position of perforated pipe and being staggeredly located out of perforation; Ridge-like structure is positioned on the leading portion inwall of perforated pipe.
Described ridge-like structure is V-type.
Described V-arrangement ridge-like structure is attached on perforated pipe inwall, in overshooting shape as parts.
The structure that described V-arrangement ridge-like structure processes on perforated pipe inwall as one, recessed.
Described penetration hole diameter is set to 5mm.
Working principle of the present invention is as follows:
The uniform perforation pipeline section of perforation, under the prerequisite not changing existing perforation number and penetration hole diameter, is changed into the perforated pipe of afterbody perforation, the leading portion inwall of perforated pipe adds ridge-like structure by the present invention, keeps caliber constant.
Introducing ridge-like structure is the property of reduction drag utilizing ridge-like structure, when the pipeline section of airflow passes with ridge-like structure, due to windward side and the different generation pressure reduction of lee face pressure in the gap of ridge and ridge, pressure reduction causes the little whirlpool contrary with carrying out flow path direction to produce, these whirlpools can produce whirlpool pad effect and thrust, through these two effects, ridge-like structure plays the effect of drag reduction, this novel perforations pipe muffling unit utilizes the property of reduction drag of ridge-like structure to carry out the flowing of air-flow in combing pipe just, make it flow process clearly middle-level, velocity jump reduces, tubulence energy reduces, to reach the object reducing reproduced air-flow noise.
Afterbody perforation pipeline section being placed in perforated pipe is conducive to increasing the low frequency acoustic attenuation performance of perforation pipeline section, just can find out from acoustics simulation result, keeping under the prerequisite that miscellaneous part is constant, the process that perforated section moves to afterbody is done to a certain perforated pipe in complicated reactive muffler, its transmission loss curve is significantly improved at low-frequency range sound deadening capacity, and effective deadening frequency band of low frequency is also expanded.
Ridge-like structure and the perforation of pipeline section afterbody are applied in novel perforations pipe, can have ideal low frequency acoustic attenuation performance that reproduced air-flow noise can be made again to reduce, be conducive to the noise elimination of silencing apparatus medium-high frequency.
Beneficial effect of the present invention is as follows:
1. the air that perforated pipe adopts ridge-like structure to come in combing pipe flows, and make perforated pipe have good aerodynamic performance, air current flow process is clearly middle-level, velocity jump reduces, tubulence energy reduces, and reduces the flow resistance of perforated pipe inwall, to reach the object reducing reproduced air-flow noise;
2. perforated pipe perforation distributions is at pipeline section afterbody, and compared to uniform perforation, its low frequency acoustic attenuation performance promotes further, and low frequency sound deadening capacity numerical value obviously increases, and deadening frequency band also obviously expands.Afterbody perforation also makes each perforation utilization ratio increase, more smooth and easy during this perforated section of the airflow passes of same flow;
3. compared to conventional punch pipe, this novel perforations pipe makes exhaust back pressure have the increase of 12%-17%, although research shows that the power of exhaust back pressure and motor is negative correlation, namely the larger engine power loss of exhaust back pressure is larger, but another important parameter is exactly deflation rate for motor, although this structure can cause the increase of exhaust back pressure, but improve deflation rate simultaneously, the raising of deflation rate can make the motor more waste gas of interior discharge at one time, and this is also a useful lifting.
Accompanying drawing explanation
Fig. 1 (a)-Fig. 1 (b) is the complicated reactive muffler of band conventional punch pipe;
Fig. 2 is the acoustics transmission loss curve of the complicated reactive muffler of band conventional punch pipe;
Fig. 3 is the acoustics transmission loss curve of the complicated reactive muffler of band novel perforations pipe;
Fig. 4 (a)-Fig. 4 (b) is the schematic diagram of apparatus of the present invention;
Fig. 5 (a)-Fig. 5 (b) is the schematic diagram of apparatus of the present invention;
Fig. 6 (a)-Fig. 6 (b) is the schematic diagram of the embodiment of the present invention;
Fig. 7 (a)-Fig. 7 (b) is the schematic diagram of the embodiment of the present invention;
In figure: 1 one two chamber perforated pipes, 2 two three chamber perforated pipes, 3 suction tude, 4 steam outlet pipes, 5 chamber I, 6 chamber II, 7 chambers III; 8 perforated pipe bodys, 9 ridge-like structures, 10 perforated sections.
Embodiment
Below in conjunction with drawings and Examples, the present invention is described further.
First, the present invention adopts the method for Numerical Simulation Analysis to analyze the acoustics of perforated pipe and aerodynamic performance, and following constipation closes Numerical Simulation Analysis result and discusses the acoustics of perforated pipe muffling unit and aerodynamic performance:
As shown in Figure 1 (a), (b) shows, be applied in complicated silencing apparatus by the uniform conventional punch pipe of perforation, Fig. 2 is the acoustics transmission loss curve of the complicated reactive muffler of band conventional punch pipe.
Although as can be seen from Figure 2 apply perforated pipe structure, its low frequency acoustic attenuation performance or not ideal.The present invention proposes ridge-like structure and afterbody perforation to merge the object realizing improving perforated pipe acoustic attenuation performance;
Embodiment 1
For the reactive muffler perforated pipe muffling unit of engineering machinery, be applied in complicated reactive muffler, as shown in Fig. 6 (a-b), comprising ridge-like structure perforated pipe 1,23 chamber perforated pipe 2, suction tude 3, steam outlet pipe 4, chamber I 5, chamber II 6, chamber III 7, air-flow enters chamber I 5 by suction tude 3, flow through ridge-like structure perforated pipe 1 again and enter chamber II 6, then air-flow enters two or three chamber perforated pipes 2 and arrives chamber III 7, is being discharged in air through steam outlet pipe 4.
The ridge-like structure adopted in this example be trapezoidal ridge-like structure and evagination on perforated pipe inwall, and going to the bottom of trapezoidal ridge-like structure realizes seamless applying with hole inner tube wall, see accompanying drawing 5 (a-b), specifically be of a size of: comprise perforated pipe body 8, trapezoidal ridge-like structure 2, perforated section 3, wherein perforated pipe body length is that internal diameter is, trapezoidal ridge-like structure is high is 1mm, upper base is that 1mm goes to the bottom is the isosceles trapezoid of 2mm, is distributed in internal face 20 encloses along the pitch helix that is 5mm; This perforated pipe perforated section penetration hole diameter is 5mm, perforation number is 40 (4 x10, circle/circles), combing first through trapezoidal ridge-like structure during airflow passes perforated pipe is flowed out from perforated section again, by drag reduction effect and the afterbody perforation raising low frequency acoustic attenuation performance of ridge-like structure, achieve the raising of perforated pipe muffling unit acoustic attenuation performance.
Fig. 3 is the acoustics transmission loss curve of the complicated reactive muffler of band novel perforations pipe.Although this new structure gesture core length increases, speed promotes, and air current flow process is clearly middle-level, and velocity jump reduces, and tubulence energy reduces, and reduces the flow resistance of perforated pipe inwall, can predict the object that can reach and reduce reproduced air-flow noise.Comparison diagram 3 is known with the transmission loss curve of Fig. 2, and the low frequency sound deadening capacity numerical value of this new structure obviously increases, and deadening frequency band also obviously expands, and obtains obvious improvement in low-frequency range noise elimination.
Embodiment 2
For the reactive muffler perforated pipe muffling unit of engineering machinery, be applied in complicated reactive muffler, as shown in Fig. 7 (a-b), wherein 1 ridge-like structure perforated pipe, 2 two three chamber perforated pipes, suction tude 3, steam outlet pipe 4, chamber I 5, chamber II 6, chamber III 7, air-flow enters 5 chambers I by 3 suction tude, flow through 1 ridge-like structure perforated pipe again and enter 6 chambers II, then air-flow enters 2 two three chamber perforated pipes and arrives 7 chambers III, is being discharged in air through 4 steam outlet pipes.
The ridge-like structure perforated pipe adopted in this example is trapezoidal ridge-like structure and is depressed on perforated pipe inwall, see accompanying drawing 4 (a-b), specifically be of a size of: comprise perforated pipe body 1, trapezoidal ridge-like structure 2, perforated section 3, wherein perforated pipe body is long is 219mm, internal diameter is 30mm, trapezoidal ridge-like structure is high is 1mm, and upper base is that 1mm goes to the bottom is the isosceles trapezoid of 2mm, is distributed in internal face 20 encloses along the pitch helix that is 5mm; This perforated pipe perforated section penetration hole diameter is 5mm, perforation number is 40 (4 x10, circle/circles), combing first through trapezoidal ridge-like structure during airflow passes perforated pipe is flowed out from perforated section again, by drag reduction effect and the afterbody perforation raising low frequency acoustic attenuation performance of ridge-like structure, achieve the raising of perforated pipe muffling unit acoustic attenuation performance.
By reference to the accompanying drawings the specific embodiment of the present invention is described although above-mentioned; but not limiting the scope of the invention; one of ordinary skill in the art should be understood that; on the basis of technological scheme of the present invention, those skilled in the art do not need to pay various amendment or distortion that creative work can make still within protection scope of the present invention.

Claims (8)

1. for the ridge-like structure perforated pipe muffling unit of reactive muffler, comprise a perforated pipe, it is characterized in that: along on the direction of air stream transportation in described perforated pipe, the perforation pipeline section being positioned at flow outlet direction is provided with the perforation of the low frequency acoustic attenuation performance for increasing perforated pipe, and the inwall being positioned at the perforated pipe in air flow inlet direction is provided with the ridge-like structure with property of reduction drag; First flow out from perforated section again through the combing of ridge-like structure during described airflow passes perforated pipe.
2., as claimed in claim 1 for the ridge-like structure perforated pipe muffling unit of reactive muffler, it is characterized in that: described ridge-like structure is trapezoidal ridge-like structure.
3., as claimed in claim 2 for the ridge-like structure perforated pipe muffling unit of reactive muffler, it is characterized in that: described trapezoidal ridge-like structure directly processes on perforated pipe inwall, and it is depressed on perforated pipe inwall.
4., as claimed in claim 2 for the ridge-like structure perforated pipe muffling unit of reactive muffler, it is characterized in that: described trapezoidal ridge-like structure is attached on perforated pipe inwall as parts, and it is overshooting shape.
5., as claimed in claim 1 for the ridge-like structure perforated pipe muffling unit of reactive muffler, it is characterized in that: described ridge-like structure is V-type ridge-like structure.
6., as claimed in claim 5 for the ridge-like structure perforated pipe muffling unit of reactive muffler, it is characterized in that: described V-type ridge-like structure is attached on perforated pipe inwall, in overshooting shape as parts.
7., as claimed in claim 5 for the ridge-like structure perforated pipe muffling unit of reactive muffler, it is characterized in that: the structure that described V-type ridge-like structure processes on perforated pipe inwall as, recessed.
8., as claimed in claim 1 for the ridge-like structure perforated pipe muffling unit of reactive muffler, it is characterized in that: described penetration hole diameter is set to 5mm.
CN201420533228.2U 2014-09-16 2014-09-16 For the ridge-like structure perforated pipe muffling unit of reactive muffler Expired - Fee Related CN204113411U (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104389665A (en) * 2014-09-16 2015-03-04 山东大学 Ridge structure perforated pipe noise elimination unit for reactive muffler
US10393003B2 (en) * 2017-02-09 2019-08-27 Ford Global Technologies, Llc Stamped aerodynamic deflector for vehicle muffler

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104389665A (en) * 2014-09-16 2015-03-04 山东大学 Ridge structure perforated pipe noise elimination unit for reactive muffler
US10393003B2 (en) * 2017-02-09 2019-08-27 Ford Global Technologies, Llc Stamped aerodynamic deflector for vehicle muffler

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CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20150121

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CF01 Termination of patent right due to non-payment of annual fee