Air filter

Abstract

The utility model discloses an air filter which comprises a shell body, the shell body comprises an inner shell body defining a filter cavity, a filter unit is arranged in the filter cavity, and the shell body further comprises an outer shell body arranged on the outer side of the inner shell body. And an air inlet channel which extends along the circumferential direction of the filtering cavity and is communicated with the filtering cavity is arranged between the outer shell and the inner shell. According to the scheme, the problem that in the prior art, an air filter is poor in mute performance is solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to an air filter. BACKGROUND

[0002] In the complex operation system of the engine, the air filter plays a crucial role. It undertakes the heavy responsibility of fine filtering the air about to enter the engine. The installation position of the air filter is carefully considered, and it is usually set in front of the carburetor or intake pipe of the engine. The purpose is to intercept dust and sand particles in the air most conveniently and efficiently. If these dust and sand particles enter the engine without any obstruction, they will cause serious wear and tear to the precision components inside the engine. In the long run, the performance of the engine will be greatly reduced, and the service life will be greatly shortened.

[0003] The basic structure of the air filter mainly consists of two key parts: the shell and the filter core. The shell serves as the external framework of the entire device, playing an important role in protecting the internal filter core and guiding the flow of air. The shell is provided with an air inlet and an air outlet. The air inlet is responsible for welcoming unfiltered external air and introducing it into the internal space of the shell. The air outlet is used to discharge clean air filtered by the filter core from the shell, and then into the engine to participate in combustion. The filter core is the core component of the air filter, which is placed inside the shell. The material of the filter core is usually special fiber material. These fibers are interwoven with each other, forming countless extremely small pores. The size of these pores is carefully designed to effectively block dust and sand particles and other impurities, while not causing too much obstruction to the flow of air. When unfiltered air flows into the internal space of the shell from the air inlet, it forms an air current inside the shell. This air current is forced to pass through the small pores on the filter core under the obstruction of the filter core. In this process, dust and sand particles and other impurities are intercepted by the filter core due to their particle size being larger than the pore size, and adhere to the surface of the filter core. The air filtered by the filter core layer by layer is discharged from the air outlet of the shell, and finally enters the engine, providing reliable protection for the efficient and stable operation of the engine.

[0004] Chinese patent document CN109882321B discloses a split type air filter, comprising a base, an air cavity capable of accommodating a filter element is arranged on the base and is composed of an upper shell and a lower shell, characterized in that: an air inlet is arranged on the upper shell, and a dust outlet is arranged on the lower shell; helical protrusions A and B with the same helical direction and matched with each other are arranged on the outer walls of the upper shell and the lower shell respectively; the helical protrusion A extends from the upper part of the upper shell to the lower part of the upper shell, the helical protrusion B extends from the upper part of the lower shell to the lower part of the lower shell, and the helical protrusions A and B make the inner walls of the upper shell and the lower shell form a helical air channel that is connected from the air inlet to the dust outlet; the tail end of the helical air channel and the dust outlet form a step B that can block the helical rotation of the air flow and change part of the air flow with impurities from helical motion to linear motion tangent to the helical air channel; wherein the lower end surface of the helical protrusion A and the lower end surface of the upper shell are located on the same horizontal plane, and the upper end surface of the helical protrusion B and the upper end surface of the lower shell are located on the same horizontal plane; the helical protrusion A has an upper end inclined surface, the helical protrusion B has a lower end inclined surface, and the upper end inclined surface and the lower end inclined surface are arranged in parallel or non-parallel; the upper end inclined surface and the lower end inclined surface constitute a helical air channel composed of the inner walls of the upper shell and the lower shell, which affects the flow direction of the air flow. Although the air filter in the above-mentioned prior art effectively solves the problems of short maintenance cycle and poor filtering effect of the air filter, it is found that there is a phenomenon of relatively large noise in use, resulting in poor quiet performance of the air filter.

[0005] In the prior art, the technical means for improving the quiet performance of the air filter is to set a porous sound-absorbing structure in the air filter, for example, Chinese patent document CN221896714U discloses an air filter structure of a vehicle, characterized in that it comprises: a lower shell; an upper shell covered on the lower shell, the upper shell and the lower shell enclosing a filter cavity, the upper shell being provided with a sound-absorbing channel structure, the first end of the sound-absorbing channel structure being in communication with the filter cavity, and the second end of the sound-absorbing channel structure being in communication with the outside space of the filter cavity; a filter element arranged in the filter cavity, the filter element being used for filtering the air entering the filter cavity, and the filtered air being introduced into the sound-absorbing channel structure; a sound-absorbing structure arranged in the sound-absorbing channel structure, the sound-absorbing structure being used for eliminating the noise of a specific frequency band entering the sound-absorbing channel structure; the sound-absorbing structure comprises a gas guide cylinder, the gas guide cylinder being capable of guiding the air entering the sound-absorbing channel structure to be introduced and discharged, the gas guide cylinder and the inner wall of the sound-absorbing channel structure being spaced apart to form a sound-absorbing cavity, and the gas guide cylinder being provided with a sound-absorbing hole in communication with the sound-absorbing cavity. Although this prior art improves the quiet performance of the air filter, the setting of the porous sound-absorbing structure greatly increases the structural complexity and manufacturing cost of the air filter, which is not conducive to popularization and use.

[0006] The prior art also has a way of arranging a filtering cavity and a muffling cavity in series to improve the noise reduction performance of the air filter, such as the air filter muffling device disclosed in Chinese Patent Document CN222084675U, which comprises a housing and a filter arranged in the housing; the housing is divided into a filtering cavity and a muffling cavity by an inner partition plate, the inner partition plate is provided with an air passing hole, the filtering cavity is communicated with the muffling cavity through the air passing hole; the housing is provided with an air inlet pipe and an air outlet pipe, the air inlet pipe is communicated with the filtering cavity through the filter, and the air outlet pipe is communicated with the muffling cavity; the housing is formed with at least one adjusting portion with adjustable axial and / or radial dimensions, and the adjusting portion corresponds to the muffling cavity. The prior art improves the noise reduction performance of the air filter to some extent, but the arrangement of the muffling cavity directly leads to an increase in the volume of the air filter by more than one time, which significantly increases the installation space requirement of the improved air filter, thereby making it difficult to install the improved air filter in the original terminal product. Practical new type content

[0007] The utility model aims at providing an air filter to solve the problem of poor noise reduction performance of the air filter in the prior art.

[0008] In order to achieve the above-mentioned purpose, the basic scheme of the utility model provides an air filter, which comprises a housing, the housing comprises an inner housing surrounding a filtering cavity, a filtering unit is arranged in the filtering cavity, and the housing further comprises an outer housing arranged outside the inner housing, an air inlet channel extending along the circumference of the filtering cavity and communicated with the filtering cavity is arranged between the outer housing and the inner housing.

[0009] The beneficial effects of the basic scheme are that: by arranging the outer housing, the air inlet channel communicated with the filtering cavity is formed between the outer housing and the inner housing, thereby effectively reducing the generation of air inlet noise and improving the noise reduction performance of the air filter.

[0010] Preferably, the air inlet channel is arranged at least two along the circumference of the filtering cavity. With such an arrangement, the air inlet position of the filtering cavity is relatively dispersed, thereby being conducive to avoiding the excessive concentration of impurities on the filtering unit, which is conducive to improving the filtering effect and reducing the noise emitted by the air filter.

[0011] Preferably, all the air inlet channels are arranged in sequence with the head and tail adjacent to each other. With such an arrangement, all the air inlet channels surround the filtering cavity, thereby being conducive to further reducing the noise emitted by the air filter.

[0012] Preferably, the air inlet of the air inlet channel is distributed along the circumference of the shell. With such an arrangement, it is beneficial for the external air to smoothly enter the air inlet channel from the air inlet, thereby facilitating the improvement of the air charging efficiency of the air cleaner.

[0013] Preferably, the length of the single air inlet channel is 1 / 5-3 / 5 of the circumference of the filter unit. With such an arrangement, the air speed is increased faster when flowing through the air inlet channel, thereby facilitating the further reduction of the noise emitted by the air cleaner.

[0014] Preferably, the filter cavity comprises an annular channel arranged around the filter unit, and the exhaust end of the air inlet channel is directly communicated with the annular channel. With such an arrangement, part of the air in the filter cavity flows along the annular channel, thereby facilitating the further reduction of the noise emitted by the air cleaner.

[0015] Preferably, a resonance unit is arranged on the outer shell at the air inlet of the air inlet channel. With such an arrangement, the resonance unit can further reduce the noise emitted by the air cleaner.

[0016] Preferably, the outer shell and the inner shell are integrally formed.

[0017] The utility model has the following beneficial effects:

[0018] With the scheme, the air outside the air cleaner needs to pass through the air inlet channel extending along the circumference of the filter cavity before entering the filter cavity, so that the noise inside the air cleaner is greatly weakened in the filter cavity and the air inlet channel when the noise is transmitted outside, thereby greatly reducing the noise emitted by the entire air cleaner relative to the prior art, and further significantly improving the noise reduction performance of the air cleaner. Compared with the scheme of adding a porous noise reduction structure in the air cleaner or adding a large noise reduction cavity outside in the prior art, the original structure of the air cleaner is improved little in the scheme, and the volume change before and after the improvement is also very small. The noise reduction performance of the air cleaner is improved at a low cost, and the improved air cleaner can be installed and used in the installation space before the improvement, avoiding the adverse effect on the structure of the terminal product using the air cleaner before the improvement. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a schematic view of an embodiment of the utility model air cleaner;

[0020] Figure 2 is Figure 1 is a sectional view along A-A;

[0021] Figure 3 is a comparison experimental data graph of the air cleaner of the utility model and a common air cleaner. DETAILED DESCRIPTION

[0022] As known to those skilled in the art, the filter unit in the utility model refers to a part for filtering air, such as the filter element in the prior art.

[0023] As known to those skilled in the art, according to the flow path of the air flow in the air inlet channel, the end where the air enters the air inlet channel (i.e. the end where the air inlet is arranged) is the leading end of the air inlet channel, and the end where the air exits the air inlet channel is the trailing end of the air inlet channel. In the utility model, the adjacent arrangement of the leading end and the trailing end refers to the adjacent arrangement of the air inlet end (the leading end) of one air inlet channel and the air outlet end (the trailing end) of another air inlet channel.

[0024] As known to those skilled in the art, the resonance unit is used to generate a vibration waveform opposite to the air inlet noise, so as to achieve the effect of canceling part of the air flow vibration sound waves.

[0025] The length of the single air inlet channel is 1 / 5-3 / 5 of the circumference of the filter unit, such as 1 / 5, 1 / 4, 1 / 3, 2 / 5, 1 / 2, 3 / 5, etc. of the circumference of the filter unit.

[0026] As known to those skilled in the art, the one-piece forming of the outer shell and the inner shell can be the bending of one plate to form the outer shell corresponding to one air inlet channel and the inner shell corresponding to another air inlet channel.

[0027] The following will be further described in detail through specific embodiments:

[0028] The reference signs in the drawings of the specification include: the outer shell 1, the inner shell 2, the air inlet channel 3, the resonance unit 4, the air inlet 5, the filter unit 6, the air outlet 7, and the annular channel 8.

[0029] The embodiments are basically as shown in the drawings: Figure 1 and Figure 2 An air filter includes a shell, the shell includes an inner shell 2 surrounding a filter cavity, and a filter unit 6 is arranged in the filter cavity. In this embodiment, the filter cavity is cylindrical, and the filter unit 6 is cylindrical. The bottom of the shell is provided with an air outlet 7 communicating with the filter cavity. The shell further includes an outer shell 1 arranged outside the inner shell 2, and an air inlet channel 3 extending along the circumference of the filter cavity and communicating with the filter cavity is arranged between the outer shell 1 and the inner shell 2. In this embodiment, the outer shell 1 and the inner shell 2 are preferably arranged in one piece.

[0030] At least two air intake channels 3 are provided along the circumference of the filter chamber. In this embodiment, four air intake channels 3 are preferably provided. All air intake channels 3 are arranged sequentially end to end, so that all air intake channels 3 surround the filter chamber. In this embodiment, the air inlets 5 of the air intake channels 3 are distributed along the circumference of the housing, so that air intake channels 3 intake air from the radial direction of the housing. The length of a single air intake channel 3 is 1 / 5 to 3 / 5 of the circumference of the filter unit 6. In this embodiment, the four air intake channels 3 are of the same length, so the length of a single air intake channel 3 is preferably about 1 / 4 of the circumference of the filter unit 6.

[0031] In this embodiment, the filter chamber includes an annular channel 8 surrounding the filter unit 6. The exhaust end of the air intake channel 3 is directly connected to the annular channel 8. A resonant unit 4 is provided on the outer casing 1 at the air intake port 5 of the air intake channel 3. In this embodiment, the resonant unit 4 is a resonant cavity disposed on the outer casing 1.

[0032] The specific implementation process is as follows: During use, outside air enters the intake channel 3 through the circumferential air inlet 5 of the housing. The air then flows along the intake channel 3 and enters the annular channel 8 in the filter chamber. At this point, some air passes through the filter unit 6 and is filtered, while some air continues to move along the annular channel 8 and passes through the filter unit 6 again and is filtered. The filtered air is then discharged from the housing through the exhaust port 7. Using this solution, outside air needs to pass through the intake channel 3 extending circumferentially along the filter chamber before entering the filter chamber. This significantly reduces the noise transmitted from inside the air filter as it propagates outward within the filter chamber and intake channel 3, thereby significantly reducing the overall noise of the air filter compared to existing technologies, and thus significantly improving the quietness of the air filter.

[0033] By installing the air filter of this invention and a conventional air filter on the same engine respectively, the noise reduction of the air filters was measured, and noise reduction curves of the two air filters at different frequencies were obtained, as shown in the figure. Figure 3 As shown. (Through) Figure 3 It can be seen that the air filter of this utility model (i.e., the new air filter) has a noise reduction of more than 10 dB.A in the range of 100Hz to 1000Hz, and especially in the range of 500Hz to 1000Hz, the noise reduction is more than 20 dB.A, which is significantly better than the existing ordinary air filter. It broadens the noise reduction frequency band, makes up for the insufficient noise reduction frequency range of the ordinary air filter, and the overall noise reduction performance is better than that of the ordinary air filter.

[0034] The above only is the embodiment of the present application, and the well-known specific structure and characteristics and other common knowledge in the scheme are not described in detail here. It should be pointed out that for those skilled in the art, without departing from the structure of the present application, a number of variations and improvements can be made, which should also be considered as the protection scope of the present application, and these will not affect the effect and practicality of the present application.

Claims

1. An air cleaner comprising a housing including an inner housing enclosing a filter chamber in which a filter unit is disposed, characterized by: The shell further comprises an outer shell arranged outside the inner shell, and an air inlet channel arranged between the outer shell and the inner shell and communicated with the filtering cavity and extending along the circumference of the filtering cavity.

2. An air cleaner as set forth in claim 1 wherein: The air inlet channel is arranged at least two along the circumference of the filtering cavity.

3. An air cleaner as set forth in claim 2 wherein: All the air inlet channels are arranged in sequence with their heads and tails adjacent to each other.

4. An air cleaner as set forth in claim 3 wherein: The air inlets of the air inlet channels are distributed along the circumference of the shell.

5. An air cleaner as set forth in claim 4 wherein: The length of a single air inlet channel is 1 / 5-3 / 5 of the circumference of the filtering unit.

6. An air cleaner as set forth in claim 5 wherein: The filtering cavity comprises an annular channel arranged around the filtering unit, and the exhaust end of the air inlet channel is directly communicated with the annular channel.

7. An air cleaner according to any one of claims 1-6, characterized in that: A resonance unit is arranged on the outer shell at the air inlets of the air inlet channels.

8. An air cleaner according to claim 7 wherein: The outer shell and the inner shell are integrally formed.

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