CN202560407U - Noise reduction engine air inflow system - Google Patents

Abstract

The utility model discloses a noise-reducing engine intake system, which comprises an intake system assembly connecting the engine with the outside air, and a noise reduction device connected with the intake system assembly. The intake system assembly is mainly composed of The intake duct (1), the air filter (2) and the intake hose (3) are connected in sequence, the intake duct (1) communicates with the outside air, and the intake hose (3) It is connected with the engine, and the muffler is a bypass pipe (4) connected with the intake hose (3), including a bypass pipe inlet (5) and a bypass pipe respectively connected with the intake hose (3). Through pipe outlet (6). The utility model has a simple structure and is realized by the superposition principle of sound waves, which can effectively control the noise at the intake end of the engine, has good noise reduction effect, and can be widely used in various engine structures, such as in automobile engines.

Description

A Noise Reduction Type Engine Air Intake System

technical field

The utility model relates to the technical field of engines, in particular to a noise reduction engine air intake system.

Background technique

With the continuous development of industry, people pay more attention to energy consumption, exhaust emissions, noise and other aspects related to environmental protection while the engine performance is improved, so that people can protect the environment and save resources while enjoying life leisurely. When the engine is working, in order to prevent sand and dust from flowing into the intake system of the engine, an air filter is usually used for filtering, which can not only ensure the effective use of the engine power, but also reduce the pollution to the environment. However, the air filter still has the problem of noise pollution, such as harsh screams and sometimes air humming when the car is running at high speed. The reason is that the intake noise signal of the car engine is usually related to the engine The harmonics of the ignition frequency are related. In many cases, the low-frequency noise peak in the radiated noise will have a great impact on the passing noise of the vehicle. However, most of the existing air filters are dry-filtered, mainly filtering dust through filter paper. According to The study found that below 1000Hz, the filter paper has little effect on the acoustic performance of the air filter, and once the car is running at high speed, the above situation will appear.

In the prior art, the air intake system of an automobile is mainly composed of an air filter, an air intake duct, and an intake hose assembly. In order to reduce the noise of the engine air intake, the air filter needs to be continuously adjusted The volume, the diameter and length of the pipeline on the air filter are optimized to control the noise, but the frequency range used is limited, and the noise reduction effect is not obvious. Therefore, the utility model proposes a The noise reduction air intake system can effectively reduce the intake noise and achieve the purpose of environmental protection.

Utility model content

The purpose of this utility model is to provide a noise-reducing engine intake system, which is equipped with a noise reduction device on the intake system assembly, which can effectively reduce intake noise, reduce the impact of engine noise on the environment, and achieve the purpose of environmental protection .

The utility model is realized through the following technical solutions: a noise-reducing engine intake system, including an intake system assembly connecting the engine and the outside air. In order to reduce the impact of engine noise on the environment, the utility model also includes a The sound-absorbing device connected to the gas system assembly can effectively reduce the frequency of sound waves through the setting of the sound-absorbing device, and the structure is simple.

In the utility model, the noise reduction device includes two structures, as follows: (1) The air intake system assembly is mainly composed of an air intake duct, an air filter, and an air intake hose connected in sequence. The air intake conduit is connected with the outside air, the air intake hose is connected with the engine, and the noise reduction device is arranged on the air intake hose.

In the above structure, the noise reduction device is a bypass pipe connected with the intake hose, including a bypass pipe inlet and a bypass pipe outlet respectively connected with the intake hose, and the sound wave is transmitted from one end of the intake hose Entering, the sound waves are divided into two paths at the entrance of the bypass pipe, one passes through the bypass pipe, the other passes through the intake hose, and meets at the exit of the bypass pipe. Using the principle of superposition of sound wave amplitudes, after the two paths of sound waves converge, you can Realize the effect of noise reduction and noise reduction.

The inner diameters of the bypass pipe inlet and the bypass pipe outlet described in the utility model are respectively 5 to 15 mm.

In order to achieve the ideal effect of noise reduction, the inner diameters of the bypass pipe inlet and bypass pipe outlet are respectively 10mm.

(2) The air intake system assembly is mainly composed of an air intake duct, an air filter and an air intake hose connected in sequence. The air intake duct is connected with the outside air, and the intake hose is connected with the engine Connected, and the noise reduction device is located on the air filter.

The noise reduction device described in the utility model is a resonant cavity fixed on the air filter, and one end of the air filter is provided with a conduit interface connected to the intake duct and a hose interface connected to the intake hose. The other end is provided with a cover plate for fixing the resonant cavity. Its structure is simple. It also uses the principle of sound wave superposition to achieve the purpose of noise reduction. The principle is: sound waves enter the air filter from the intake duct, At the intersection of the cover plate and the resonant cavity, sound waves of different step lengths converge. When a part of the sound wave of the intake duct and the sound wave of the resonant cavity are superimposed and the amplitude is zero, the effect of reducing noise can be achieved.

The utility model is also provided with a waste gas recovery pipe on the air intake hose.

Compared with the prior art, the utility model has the following advantages and beneficial effects:

(1) The utility model has a reasonable design and improves the engine intake system assembly, which avoids the influence of the engine due to the low-frequency noise peak in the radiation noise, changes the intake noise signal of the engine, and effectively controls the intake of the engine. The noise at the gas end has a good noise reduction effect, and can be widely used in various engine structures, such as: application in automobile engines.

(2) The structure of the utility model is simple, the design of both the bypass pipe and the resonant cavity is relatively simple, and its principle is also relatively simple. They are all realized by using the superposition principle of sound waves, so that two different sound waves are superimposed on each other, so that the arrival The sound wave amplitude at the engine is zero, thereby achieving the effect of reducing noise.

(3) In the actual production process, specific values such as the length of the connecting pipe and the volume of the resonant cavity can be obtained through calculation. The production process is relatively simple, and it has the advantages of low cost and easy installation.

Description of drawings

Fig. 1 is a structural schematic diagram when the utility model adopts a bypass pipe.

Fig. 2 is a structural schematic view of the utility model when a resonant cavity is used.

Among them, 1—intake duct, 2—air filter, 3—intake hose, 4—bypass pipe, 5—bypass pipe inlet, 6—bypass pipe outlet, 7—resonant cavity, 8—cover plate, 9 —Exhaust gas recovery pipe.

Detailed ways

The utility model will be further described in detail below in conjunction with the examples, but the implementation of the utility model is not limited thereto.

Example:

For the existing engine field, energy consumption, exhaust emissions, noise and other environmental protection-related issues have become the main direction of its development, especially in the automotive industry, the improvement of engine performance has been closely related to people's lives. In the prior art, the air filter 2 in the automobile air intake system can effectively filter impurities such as dust and gravel in the air, but there is a problem of noise pollution, such as: harsh sharp noises will appear when the automobile is running at high speed. Scream, sometimes there will be empty sound, in order to overcome this phenomenon, the utility model proposes a noise reduction type engine intake system, including the intake system assembly connecting the engine and the outside air and the intake system assembly In the prior art, in order to reduce the noise of the engine air intake, the volume of the air filter 2, the diameter and length of the pipeline on the air filter 2 need to be continuously adjusted during the design process of the air filter 2. Optimized for noise control, but its frequency range is limited, and the noise reduction effect is not obvious, but in the utility model, through the setting of the noise reduction device, it can not only effectively reduce the frequency of sound waves, but also achieve the purpose of noise reduction , and also has the advantages of simple structure and low cost.

The noise reduction device described in the utility model includes two structures, as follows:

(1) Figure 1 is a structural diagram when the silencer is a bypass pipe 4. As shown in Figure 1, the intake system assembly is mainly composed of an intake duct 1, an air filter 2 and an intake hose 3 connected in sequence. The intake duct 1 communicates with the outside air; the intake hose 3 communicates with the engine; and it can be seen from Fig. 1 that the silencer is a bypass pipe 4 communicating with the intake hose 3, including 3 Connected bypass pipe inlet 5 and bypass pipe outlet 6, the sound wave enters from one end of the intake hose 3, and the sound wave is divided into two paths at the bypass pipe inlet 5, one passes through the bypass pipe 4, and the other passes through the intake air The hose 3 meets at the outlet 6 of the bypass pipe. Using the principle of superposition of sound wave amplitudes, after the two sound waves converge, the effect of noise reduction can be achieved.

In the above structure, if the path difference between the two sound waves is λ/2, the phase difference between the two sound waves is 180°. After the two sound waves merge, some of the sound wave amplitudes are superimposed to zero, which has the effect of noise reduction. At the same time, we can obtain the length Ld of the bypass pipe 4 through calculation, the calculation formula is as follows: Ld=n·λ/2=c·n/2f (n=1, 3, 5...), the sound wave frequency is 170Hz For example, in theory, the bypass pipe 4 can eliminate the sound of odd multiples of 170Hz. For example, when the frequency is 173Hz, take n=1, then Ld=1000mm (where c is the speed of sound, c=340m/s, λ is the sound wave wavelength, f frequency, n is the sound wave number).

In order to better realize the noise reduction function of the bypass pipe 4, the inner diameters of the bypass pipe inlet 5 and the bypass pipe outlet 6 are respectively 5-15 mm, and when the inner diameters of the bypass pipe inlet 5 and the bypass pipe outlet 6 are respectively 10mm, the noise reduction effect is the most ideal.

(2) Figure 2 is a structural diagram when the noise reduction device is a resonant cavity 7, as shown in Figure 2, the only difference is that the installation form of the noise reduction device is different, in Figure 2, the noise reduction device is a resonator fixed on the air filter 2 Cavity 7 is a cavity structure that is not connected to air filter 2. One end of air filter 2 is provided with a conduit interface connected to intake conduit 1 and a hose interface connected to intake hose 3. On the other end of air filter 2 One end is provided with a cover plate 8 for fixing the resonant cavity 7 , and an exhaust gas recovery pipe 9 is provided on the intake hose 3 . Its structure is simple, and it also achieves the purpose of noise reduction through the principle of sound wave superposition.

，式中C为声速；S为谐振腔小孔面积；l为孔径有效长度；V为谐振腔体积。考虑谐振腔7的长度和高度受到发动机机舱内的限制，最后得到谐振腔7的最佳尺寸为S=1018mm²，l=20mm，V=106mm³。 The realization principle is as follows: the sound wave enters the air filter 2 from the intake duct 1, and at the cover plate 8 of the air filter 2 (that is, the intersection with the resonant cavity 7), the sound waves with different step lengths converge. λ/2, the phase difference between the two sound waves is 180°, and after the two sound waves converge, some of the sound wave amplitudes are superimposed to zero, thus achieving the effect of noise reduction and noise reduction. Among them, the noise reduction frequency of the resonant cavity 7 is

, where C is the speed of sound; S is the small hole area of the resonant cavity; l is the effective length of the aperture; V is the volume of the resonant cavity. Considering that the length and height of the resonant cavity 7 are limited by the engine compartment, the optimal size of the resonant cavity 7 is finally obtained as S=1018mm ² , l=20mm, and V=106mm ³ .

The utility model has a simple structure, and the design of the bypass pipe 4 and the resonant cavity 7 is relatively simple, and they are all realized by using the superposition principle of sound waves, which can effectively control the noise at the intake end of the engine, have good noise reduction effects, and can be widely used In various engine structures, such as: application in automobile engines.

The above is only a preferred embodiment of the utility model, and does not limit the utility model in any form. Any simple modification or equivalent change made to the above embodiments according to the technical essence of the utility model falls within the scope of the present utility model. Within the protection scope of the present utility model.

Claims (3)

1. A noise reduction type engine air intake system, comprising an air intake system assembly communicating with the engine and outside air and a muffler connected to the air intake system assembly. Composed of air duct (1), air filter (2) and intake hose (3), the intake duct (1) communicates with the outside air, and the intake hose (3) communicates with the engine , characterized in that: the noise reduction device is a bypass pipe (4) connected to the intake hose (3), including a bypass pipe inlet (5) and a bypass pipe respectively connected to the intake hose (3). Through pipe outlet (6). 2. A noise reduction engine air intake system according to claim 1, characterized in that: the inner diameters of the bypass pipe inlet (5) and bypass pipe outlet (6) are 5-15mm respectively. 3. A noise-reducing engine intake system according to claim 2, characterized in that: the inner diameters of the bypass pipe inlet (5) and the bypass pipe outlet (6) are respectively 10mm.

Images