CN201486706U - Noise reduction device for engine air intake system - Google Patents

Abstract

The utility model discloses a noise reduction device for an engine air intake system, which comprises an intake hose, an air filter, and an air induction pipe. There is a resonant cavity at the lower part of the device, and the cross-sectional area of the air induction pipe varies from small to large from the air filter to the engine. Due to the above structure, the connecting device has the following advantages: 1. Effectively reduce the intake noise of the automobile engine; 2. 1. The structure is simple, which is convenient for production and the transformation of existing products; 3. The mutual cancellation of sound waves is used to reduce noise, without adding other redundant devices, and the production cost is low.

Description

Noise reduction device for engine air intake system

Involved areas

The utility model relates to an automobile engine intake system, in particular to a noise reduction device for the engine intake system.

Background technique

Noise is a by-product of industrial society, and together with air pollution and water pollution, it is considered to be the three major public hazards in the world today. Compared with the other two public hazards, noise has the widest influence, the most direct feeling, and the most people's feedback. Automobiles are increasingly popular and growing as a main means of transportation, so the environmental pollution caused by automobile noise is also becoming more and more serious. With the increasingly fierce competition in the automobile market, the comprehensive performance-to-price ratio of vehicles of the same grade is getting closer and has reached a higher level. Therefore, improving the level of vehicle noise control has become a new focus of competition and a direction of technological development. In this context, the NVH (Noise/Vibration/Harshness) performance of vehicles is gradually evolving into an important design index.

The noise of the engine is the main noise source of the car, and with the rapid development of engine technology, the noise of the engine has been greatly reduced. The contribution of other noise sources other than the engine, such as intake noise, to the overall noise of the vehicle is relatively increasing, and the issue of intake noise is receiving more and more attention. It is a problem to be solved in the prior art to provide a method that can reduce the intake noise of the automobile engine.

Utility model content

The technical problem to be solved by the utility model is to provide a noise reduction device for an engine intake system to achieve the purpose of reducing the intake noise of an automobile engine.

In order to solve the above-mentioned technical problems, the technical proposal of the present invention is a noise reduction device for an engine air intake system, which includes an air intake hose, an air filter, and an air induction pipe, and is characterized in that: the air intake hose There is a wavelength tube on the upper part of the air filter, a resonant cavity is set on the lower part of the air filter, and the cross-sectional area of the air induction pipe changes from small to large from the air filter to the engine, so that the engine intake system can be comprehensively improved through three aspects of improvement. noise reduction.

The length of the wavelength tube is 1/4 of the length of the sound wave in the air filter, so that the sound wave returned to the main pipe and the sound wave of the same frequency in the main pipe are opposite in phase and cancel each other to achieve noise reduction.

The resonant cavity is connected with the air filter through a connecting pipe, and the noise is reduced by controlling the length of the connecting pipe.

The air induction pipe is connected with the guide pipe, and the guide pipe is fixed in the air filter by rivets, thereby reducing noise and ensuring that the air intake resistance will not be too large.

A noise reduction device for an engine air intake system. Due to the above-mentioned structure, the device has the following advantages: 1. Effectively reduce the intake noise of an automobile engine; 2. Simple structure, convenient for production and transformation of existing products; 3. Utilize The mutual cancellation of the sound waves reduces the noise, no additional devices are added, and the production cost is low.

Description of drawings

Below in conjunction with accompanying drawing and specific embodiment the utility model is described in further detail;

Fig. 1 is the structural representation of the noise reducing device of a kind of engine intake system of the present utility model;

Fig. 2 is a schematic diagram of the internal structure of the air filter of the noise reduction device of the engine intake system of the present invention;

Fig. 3 is a schematic diagram of the connection between the air filter and the resonator of the noise reduction device of the engine intake system of the present invention;

In Fig. 1-3, 1. Air filter; 2. Air induction pipe; 3. Air intake hose; 4. Resonant cavity; 5. Wavelength tube; 6. Guide pipe; 7. Connecting pipe.

Detailed ways

As shown in Figures 1-3, a noise reduction device for an engine intake system includes an intake hose 3, an air filter 1, and an air induction pipe 2, and is characterized in that: the intake hose 3 is provided with There is a wavelength tube 5, a resonant cavity 4 is provided at the lower part of the air filter 1, and the cross-sectional area of the air intake pipe 2 changes from small to large from the air filter 1 to the engine, so that the engine intake system can be improved through three aspects. Full noise reduction.

The length of the wavelength tube 5 is 1/4 of the length of the sound wave in the air filter 1, so that the sound wave folded back into the main pipe and the sound wave of the same frequency in the main pipe are opposite in phase and cancel each other to achieve noise reduction.

The resonant cavity 4 is connected with the air filter 1 through the connecting pipe 7, and the noise is reduced by controlling the length of the connecting pipe 7.

The air induction pipe 2 is connected with the guide pipe 6, and the guide pipe 6 is fixed in the air filter 1 by rivets, so as to reduce noise and ensure that the air intake resistance will not be too large.

Reasonable design and selection of the air filter 1 can effectively control the intake noise, and the volume occupied by the air filter 1 can be used as the expansion cavity of the expansion muffler. The air filter is equivalent to an expansion muffler, and there are two factors that affect its transmission loss: the expansion ratio and the length of the filter. Reducing the cross-sectional area of the air intake pipe 2 can increase the expansion ratio to reduce noise. The utility model designs a bleed air pipe 2 whose diameter changes. The cross-sectional area of the bleed air pipe 2 changes from small to large from the air filter 1 to the engine, which is beneficial to noise reduction and can also ensure that the air intake resistance is not too large; The air guide pipe 2 protrudes into the guide pipe 6 in the body of the air filter 1, which can cooperate with the design of the air passage in the body of the air filter 1 to eliminate noise and improve the transmission loss of the filter.

As shown in Figure 3, the formula for calculating the resonant frequency of the resonant cavity muffler is:

f＝(C/2π)*(S/(L*V))1/2

Where: C- is the speed of sound in air

L-connecting pipe length

S-connection pipe average cross-sectional area

V- volume of resonant cavity

f-resonant frequency

For example, the length of the connecting pipe of the resonant cavity is L=20mm, the cross-sectional diameter of the connecting pipe d=20mm, the volume V=2.2L, and the corresponding resonant frequency f=83Hz.

The quarter-wavelength tube 5 is a closed tube installed on the intake hose 3. After the sound wave enters the wavelength tube 5 from the intake hose 3, the sound wave is reflected back to the intake hose 3 by the closed end. Some The sound wave of the frequency and the sound wave of the same frequency in the main tube cancel each other due to the opposite phase, so as to achieve the purpose of noise reduction.

The frequency at which quarter wave tube 2 resonates is:

${\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; =</span>\frac{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; c</span>}}{\mathrm{<span\; class="notranslate">\; 4</span>}\mathrm{<span\; class="notranslate">\; L</span>}}$

For example, the quarter wave tube is connected to the intake hose, the length is about 190mm, and the resonant frequency is 430Hz.

The utility model has been exemplarily described above in conjunction with the accompanying drawings. Obviously, the specific implementation of the utility model is not limited by the above-mentioned method, as long as various improvements of the method concept and technical solutions of the utility model are adopted, or the utility model can be directly implemented without improvement. Those applied to other occasions are all within the protection scope of the present utility model.

Claims (4)

1. the denoising device of an engine aspirating system, comprise air induction hose (3), air-strainer (1), air entraining pipe (2), it is characterized in that: described air induction hose (3) is provided with wavelength pipe (5), air-strainer (1) bottom is provided with resonant cavity (4), and the cross-section area of air entraining pipe (2) is to change to big from air-strainer (1) to motor by little.

2. the denoising device of a kind of engine aspirating system according to claim 1 is characterized in that: the length of described wavelength pipe (5) be in the air-strainer (1) wave length of sound 1/4th.

3. the denoising device of a kind of engine aspirating system according to claim 1, it is characterized in that: described resonant cavity (4) is connected by connecting tube (7) with air-strainer (1).

4. the denoising device of a kind of engine aspirating system according to claim 1, it is characterized in that: described air entraining pipe (2) is connected with honeycomb duct (6), and honeycomb duct (6) is fixed in the air-strainer (1) by rivet.

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