CN110748506A - Noise elimination device for turbocharger - Google Patents

Abstract

The invention discloses a noise reduction device for a turbocharger, comprising an inlet pipe, a conical muffler assembly coaxially connected to the right end of the inlet pipe, and a first column coaxially connected to the right end of the cone muffler assembly in turn. The cone-type muffler assembly and the second column-type muffler assembly and the outlet pipe coaxially connected to the right end of the second column-type muffler assembly are used for muffling in the frequency range of 2300Hz~4830Hz. The first column-type muffler assembly and the second column-type muffler assembly are used for muffling in the frequency range of 460 Hz to 2300 Hz. The muffling device implemented in the present invention has the advantages of simple and compact structure, wide muffling range and large muffling amount, and the amplitude of transmission loss in the frequency range of 460 Hz to 4830 Hz all reaches more than 20 dB, which effectively attenuates medium and high frequency broadband turbochargers. Intake noise.

Description

A muffler device for a turbocharger

technical field

The present invention relates to the technical field of noise reduction and noise reduction, and more particularly to a noise reduction device for a turbocharger.

Background technique

The introduction of a turbocharger into an engine can improve the power and fuel economy of the car, but the noise generated by the turbocharger during high-frequency vibration and high-speed rotation will have a great impact on the service life and comfort of the car. The frequency range is mainly concentrated in the range of 600Hz~3000Hz. When working, a wide noise band will be generated in this frequency range, so the turbocharger intake system needs a wide-band muffler in this frequency range to eliminate its unique Hiss sound, deflation sound, synchronous and sub-synchronous noise. , and sufficient noise reduction is required in this frequency band. The pure resistive muffler cannot completely eliminate the broadband noise of the turbocharger because of its limited muffling amplitude in the full frequency range. In addition, the installation space of the current engine compartment is getting smaller and smaller, and there is a higher requirement on the space size of the muffler.

The muffler principle of the perforated muffler is similar to the Heimholtz resonance effect. The impedance effect generated when the sound wave passes through the through hole of the perforated pipe can obviously attenuate the sound wave of the same frequency as the resonance frequency of the resonance chamber, and has good muffling ability for medium and high frequency noise. And the anechoic frequency band is wider. By controlling the number of resonant cavities, the number, diameter and depth of the through holes, the noise reduction effect of the full frequency and high noise reduction can be achieved. In recent years, there have been more and more studies on the transmission loss of the perforated pipe anechoic structure. JW Sullivan et al. established an acoustic impedance model and found that the acoustic wave velocity has a great influence on the acoustic impedance rate. K. Narayana Rao et al. proposed an empirical formula for calculating the acoustic impedance of perforated panels. Kang Zhongxu analyzed and designed an empirical acoustic impedance rate model for the effect of perforation rate, airflow parameters and frequency on acoustic impedance.

However, the above studies are all based on single-chamber perforated structures. The traditional single-cavity resonant muffler can only suppress the noise in a narrow frequency band, but cannot attenuate the medium and high frequency noise in a wide frequency band, and has poor sound-absorbing ability, and the muffler has problems such as large size and complex structure.

SUMMARY OF THE INVENTION

In order to solve the shortcomings of the prior art, the present invention provides a noise reduction device for a turbocharger, which realizes that the transmission loss amplitude in the frequency range of 460Hz~4830Hz reaches more than 20dB, effectively attenuating The intake noise of the broadband turbocharger in the middle and high frequencies.

The technical effect to be achieved by the present invention is achieved through the following scheme: a muffler device for a turbocharger, comprising an inlet pipe, a conical muffler assembly coaxially connected to the right end of the inlet pipe, and coaxially connected to the conical muffler in turn. A first cylindrical muffler assembly and a second cylindrical muffler assembly at the right end of the muffler assembly and an outlet pipe coaxially connected to the right end of the second cylindrical muffler assembly, the cone-shaped muffler assembly is used for frequencies of 2300Hz to 4830Hz The first column-type sound-absorbing component and the second column-type sound-absorbing component are used for sound reduction in the frequency range of 460 Hz to 2300 Hz.

Preferably, the conical muffler assembly includes a first center pipe and a plurality of first resonant cavities which are arranged around the outer layer of the first center pipe and whose volumes increase in equal proportions from left to right, the first center pipe is provided with There is a first through hole.

Preferably, the number of the first resonant cavity is four.

Preferably, the first through hole is a rectangular through hole.

Preferably, the first cylindrical muffler assembly includes a second central pipe and a second resonant cavity surrounding the outer layer of the second central pipe, and the second central pipe is provided with a second through hole.

Preferably, the second cylindrical muffler assembly comprises a third center pipe, a fourth center pipe surrounding the outer layer of the third center pipe, and a third resonant cavity surrounding the outer layer of the third center pipe. The third central tube is provided with a third through hole, and the fourth central tube is provided with a fourth through hole.

Preferably, the diameter of the fourth through hole is larger than the diameter of the third through hole.

Preferably, the second through hole, the third through hole and the fourth through hole are all circular through holes.

Preferably, the first resonant cavity, the second resonant cavity and the third resonant cavity are separated by cavity walls with the same wall thickness to form mutually independent cavities.

Preferably, the inlet pipe and the outlet pipe are fixedly connected to the intake pipe of the turbocharger through flanges.

The present invention has the following advantages:

The muffler device of the embodiment of the present invention has a simple and compact structure, a wide range of muffling, and a large amount of muffling. The amplitude of transmission loss in the frequency range of 460 Hz to 4830 Hz is all above 20 dB, which effectively attenuates medium and high frequency broadband turbochargers. Intake noise.

Description of drawings

1 is a schematic plan view of a muffler device for a turbocharger according to the present invention;

FIG. 2 is a cross-sectional structural schematic diagram of a muffler device for a turbocharger according to the present invention;

3 is a meshing diagram of a simulation model of a noise reduction device for a turbocharger according to the present invention;

FIG. 4 is a simulation diagram of a sound transmission loss curve of a muffler device for a turbocharger according to the present invention.

Detailed ways

The present invention will be described in detail below with reference to the drawings and embodiments, examples of which are shown in the drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary, and are intended to explain the present invention and should not be construed as limiting the present invention.

In the description of the present invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", The orientation or positional relationship indicated by "horizontal", "top", "bottom", "inside", "outside", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, and It is not indicated or implied that the indicated device or element must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as limiting the invention.

Furthermore, the terms "first", "second" and "third" are used for descriptive purposes only, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature defined as "first", "second", "third" may expressly or implicitly include one or more of that feature. In the description of the present invention, "plurality" means two or more, unless otherwise expressly and specifically defined.

In the present invention, unless otherwise expressly specified and limited, the terms "installed", "connected", "connected", "fixed" and "arranged" should be understood in a broad sense, for example, it may be a fixed connection or a It can be a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, or it can be the internal connection of two elements or the interaction between the two elements. . For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

Referring to FIGS. 1 and 2 , an embodiment of the present invention provides a noise reduction device for a turbocharger, which is connected to the intake pipe of the turbocharger, including an inlet pipe 100 , which is coaxially connected to the inlet pipe 100 The conical muffler assembly 200 at the right end, the first cylindrical muffler assembly 300 and the second cylindrical muffler assembly 400 coaxially connected to the right end of the conical muffler assembly 200 and coaxially connected to the second cylindrical muffler The outlet pipe 500 at the right end of the assembly 400, the conical muffler assembly 200 is used for muffling in the frequency range of 2300Hz to 4830Hz, and the first cylindrical muffler assembly 300 and the second cylindrical muffler assembly 400 are used for 460Hz Noise cancellation in the frequency range of ~2300Hz. The muffler device of the embodiment of the present invention has a simple and compact structure, a wide range of muffling, and a large amount of muffling. The amplitude of transmission loss in the frequency range of 460 Hz to 4830 Hz is all above 20 dB, which effectively attenuates medium and high frequency broadband turbochargers. Intake noise.

Specifically, the cone-shaped muffler assembly 200 includes a first central pipe 210 and a plurality of first resonant cavities 220 (the plurality of first resonant cavities 220 , which are arranged in the outer layer of the first central pipe 210 in equal proportions from left to right and increase in volume from left to right). The first resonant cavity 220 forms a tapered resonant cavity), and the first central tube 210 is provided with a first through hole 230 . Since the space in the conical resonator is relatively small, the muffler frequency value is high, which can be used for muffling in the frequency range of 2300Hz~4830Hz.

In the embodiment of the present invention, too many cavities of the first resonant cavity 220 will reduce the frequency band, and too few cavities will make the anechoic frequency discontinuous. Therefore, the number of the first resonant cavity 220 is preferably 4, the volume of each first resonant cavity 220 is proportionally increased from left to right to form a cone structure, and the specific volume of the first resonant cavity 220 can be designed into different specifications according to the frequency range of different noise reduction requirements . The first through hole 230 is preferably a rectangular through hole, and the depth and size of the rectangular through hole can be designed according to the frequency range required for noise reduction (for example, as shown in FIG. There are three spaced rectangular through holes on the 210), since the rectangular through holes are easier to process than the circular through holes, and the silencing frequency is related to the perforation rate, the rectangular through holes and the circular through holes provide the perforation area, and the perforation rate is The ratio of the area to the total area of the perforated pipe.

The first cylindrical muffler assembly 300 includes a second central pipe 310 and a second resonant cavity 320 arranged around the outer layer of the second central pipe 310, and the second central pipe 310 is provided with a second through hole 330; The second cylindrical muffler assembly 400 includes a third center pipe 410, a fourth center pipe 420 arranged around the outer layer of the third center pipe 410, and a third resonant cavity 430 arranged around the outer layer of the third center pipe 410, The third central tube 410 defines a third through hole 440 , and the fourth central tube 420 defines a fourth through hole 450 . The impedance mismatch effect is induced by connecting the central tube with through holes in series and parallel, which is analogous to the combination of Heimholtz resonators, so the noise reduction frequency is relatively low, which can be used for noise cancellation in the frequency range of 460Hz~2300Hz. Voice. It should be understood that the second central tube 310 and the third central tube 410 may be the same central tube formed integrally, or may be formed separately and then spliced and fixed.

In the embodiment of the present invention, the second through hole 330 , the third through hole 440 and the fourth through hole 450 are preferably circular through holes, and the diameter of the fourth through hole 450 is preferably larger than that of the third through hole 440 The diameter can widen the lower cutoff frequency of the low frequency. It should be understood that the second through hole 330 , the third through hole 440 and the fourth through hole 450 can also be designed with different diameters according to different frequency ranges required for noise reduction.

In this embodiment of the present invention, in order to facilitate processing and fabrication, the first resonant cavity 220 , the second resonant cavity 320 and the third resonant cavity 430 (equivalent to six cavities) are preferably separated by cavity walls with the same wall thickness. Independent chambers, the inlet pipe 100 , the first central pipe 210 , the second central pipe 310 , the third central pipe 410 and the outlet pipe 500 are preferably integrally formed, the inlet pipe 100 , the first central pipe 210 The thicknesses of the second central pipe 310, the third central pipe 410, the fourth central pipe 420 and the outlet pipe 500 are preferably the same as the thickness of the cavity wall of the resonant cavity.

In the embodiment of the present invention, the inlet pipe 100 and the outlet pipe 500 may be fixedly connected to the intake pipe of the turbocharger through flanges, but are not limited thereto. The material of the muffler device is stainless steel or carbon steel, and the cone-type muffler assembly 200 and the column-type muffler assembly may be formed separately and then combined into one, but not limited to this.

The muffler device of the present invention is installed in the intake duct of the turbocharger. When the engine is running, the airflow passes through the muffler device unobstructed. When the sound wave passes through the through hole of the central pipe, the through hole and the resonance cavity form an elastic vibration system. , When the frequency of the internal sound wave of the intake duct is the same as the natural frequency of the vibration system of the resonant cavity, the system will produce a resonance effect, which will cause the air column in the through hole to move faster, and the friction between the air and the cavity wall will increase, and the sound energy will be converted to the maximum extent. It is heat energy, and the noise reduction effect on the noise in the intake duct is the greatest at this time.

In the embodiment of the present invention, the finite element simulation software COMSOL Muitiphysics 5.3a is used to simulate and analyze the acoustic performance of the muffler device of the present invention, and the control noise reduction effect of the muffler device is verified. Please refer to FIG. 3 , which is a schematic diagram of mesh division of the air domain inside the muffler. The medium of the fluid domain is air, the inlet and outlet of the air domain are set, and the transmission loss of the model is calculated by the sound-structure coupling module in the software. Please refer to Figure 4, which is the simulation result of the transmission loss of the muffler. The transmission loss amplitude in the frequency range of 460Hz~4830Hz is all above 20dB.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present invention and not to limit them. Although the embodiments of the present invention have been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should It should be understood that the technical solutions of the embodiments of the present invention can still be modified or equivalently replaced, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims (10)

1. A sound-absorbing device for a turbocharger, characterized in that it comprises an inlet pipe, a conical muffler assembly coaxially connected to the right end of the inlet pipe, a first coaxial muffler assembly coaxially connected to the right end of the conical muffler assembly in turn. A cylindrical muffler assembly, a second cylindrical muffler assembly, and an outlet pipe coaxially connected to the right end of the second cylindrical muffler assembly. The first column-type muffler assembly and the second column-type muffler assembly are used for muffling in the frequency range of 460 Hz to 2300 Hz. 2 . The muffler device for a turbocharger as claimed in claim 1 , wherein the conical muffler assembly comprises a first center pipe and a second center pipe surrounding the outer layer of the first center pipe. 3 . There are several first resonant cavities whose volumes increase in equal proportions from left to right, and the first central tube is provided with a first through hole. 3 . The muffler device for a turbocharger according to claim 2 , wherein the number of the first resonance cavities is four. 4 . 4 . The muffler device for a turbocharger according to claim 2 , wherein the first through hole is a rectangular through hole. 5 . 5 . The muffler device for a turbocharger according to claim 2 , wherein the first cylindrical muffler assembly comprises a second center pipe and an outer layer surrounding the second center pipe. 6 . the second resonant cavity, the second central tube is provided with a second through hole. 6 . The muffler device for a turbocharger according to claim 5 , wherein the second cylindrical muffler assembly comprises a third center pipe, which is arranged around the outer layer of the third center pipe. 7 . The fourth central tube and the third resonant cavity are arranged on the outer layer of the third central tube, the third central tube is provided with a third through hole, and the fourth central tube is provided with a fourth through hole. 7 . The muffler device for a turbocharger according to claim 6 , wherein the diameter of the fourth through hole is larger than the diameter of the third through hole. 8 . 8 . The noise reduction device for a turbocharger according to claim 6 , wherein the second through hole, the third through hole and the fourth through hole are all circular through holes. 9 . 9 . The muffler device for a turbocharger according to claim 6 , wherein the first resonant cavity, the second resonant cavity and the third resonant cavity are divided by cavity walls of the same wall thickness. 10 . Separated to form mutually independent chambers. 10 . The muffler device for a turbocharger according to claim 1 , wherein the inlet pipe and the outlet pipe are fixedly connected to the intake pipe of the turbocharger through flanges. 11 .

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