CN220204021U - Air filter and motorcycle - Google Patents

Abstract

The present application relates to an air filter and a motorcycle. The air filter comprises a filter box, an air inlet pipe, a protective cover and a rectifying piece. Be provided with air inlet and gas outlet on the rose box, the intake pipe is including the inlet end and give vent to anger the end, the intake pipe wears to locate the air inlet for the inlet end is located outside the rose box, and the end of giving vent to anger is located the rose box, and the safety cover is connected in the intake pipe, and forms the protection chamber, and the inlet end is located the protection intracavity, and the rectifier includes ring portion and extension, and the ring portion sets up around the outside of inlet end, and the extension sets up around the outside of ring portion, and the extension protrusion is in the terminal surface of the orientation inlet end place one side of ring portion. The application air filter can reduce dust and rainwater entering the filter box, can inhibit the turbulent flow formation of air flow in the air inlet pipe, improves air inlet efficiency, and further improves the performance of the engine.

Description

Air filter and motorcycle

Technical Field

The application relates to the technical field of air filtration, in particular to an air filter and a motorcycle.

Background

An engine of a motor vehicle such as a motorcycle is an internal combustion engine, and is connected to an intake system, and air is supplied to the engine through the intake system to perform an operation. The air inlet system comprises an air filter, wherein air enters the air filter from an air inlet of the air filter, is filtered by a filter element in the air filter, is discharged from an air outlet of the air filter, and enters the engine.

However, the air filter directly admits air, dust and liquid water easily enter the air filter along with the air, increasing the work load of the filter element, affecting the filter element life, and even affecting the engine life. If the waterproof and dustproof device is additionally arranged on the air inlet, the air inflow is easily influenced, the output power of the engine is reduced, and the performance of the engine is further influenced.

Disclosure of Invention

Based on this, it is necessary to provide an air filter and a motorcycle for the conventional air filter that cannot achieve waterproofing and dust prevention while maintaining the intake air amount.

In one aspect, the present application relates to an air filter comprising:

the filter box is provided with an air inlet and an air outlet;

the air inlet pipe comprises an air inlet end and an air outlet end, and the air inlet pipe penetrates through the air inlet, so that the air inlet end is positioned outside the filter box, and the air outlet end is positioned in the filter box;

the protective cover is connected with the air inlet pipe and forms a protective cavity, and the air inlet end is positioned in the protective cavity;

the rectifying piece comprises a ring part and an extension part, wherein the ring part is arranged around the outer side of the air inlet end, the extension part is arranged around the outer side of the ring part, and the extension part protrudes out of the end face of the ring part, which faces towards the side where the air outlet end is located.

In one embodiment, the fairings are integrally formed with the air inlet pipe.

In one embodiment, the filter box comprises a first box body, a second box body and a filter assembly, the air inlet is arranged on the first box body, the air outlet is arranged on the second box body, and the first box body and the second box body are connected to form an accommodating space in a surrounding mode, and the filter assembly is arranged in the accommodating space.

In one embodiment, the first box comprises a cover body and a shell cover which are mutually communicated, the cover body is covered on the filter assembly, the shell cover is arranged on one side, deviating from the filter assembly, of the cover body, the length of the shell cover is smaller than that of the cover body, so that a concave part is formed at one end of the first box, the protective cover is arranged on the concave part, the air inlet is formed on the side wall, facing the protective cover, of the shell cover, and the air outlet is positioned on the side wall, facing away from one end of the concave part, of the second box.

In one embodiment, the side wall of the housing, which is provided with the air inlet, is inclined towards the side away from the protective cover relative to the cover body.

In one embodiment, the filter assembly comprises a mounting plate and a filter element, wherein a mounting groove is formed in the mounting plate, two ends of the peripheral wall of the mounting groove extend out of the first box body and the second box body respectively in the direction perpendicular to the mounting plate, and the filter element is arranged in the mounting groove.

In one embodiment, the air inlet pipe is inclined with respect to the mounting plate, and the distance from the air inlet end to the mounting plate is greater than the distance from the air outlet end to the mounting plate.

In one embodiment, the protective cover is provided with a vent, the vent is opposite to the air inlet, and a grid is arranged on the vent.

In one embodiment, the grille comprises a plurality of grille bars, and two ends of the plurality of grille bars are respectively connected with the top side edge of the air vent and the bottom side edge of the air vent.

On the other hand, the application also relates to a motorcycle, which comprises an engine, a vehicle body and the air filter, wherein the air filter is arranged on the vehicle body, and the air outlet is communicated with the engine.

According to the air filter, the air inlet end of the air inlet pipe is arranged in the protection cavity of the protection cover, so that the dust and rain entering the filter box can be reduced; on the other hand, through setting up the ring portion in the outside of air inlet, set up extension around the ring portion, suppressed the formation of turbulent flow when the air current gets into in the intake pipe through the air inlet, improved air inlet efficiency, and then promoted engine performance.

Drawings

Fig. 1 is a schematic structural diagram of an air filter according to an embodiment of the present application.

Fig. 2 is an exploded view of an air filter according to an embodiment of the present application.

Fig. 3 is a cross-sectional view of an air filter in an embodiment of the present application.

Fig. 4 is an enlarged schematic view at a in fig. 3.

Fig. 5 is a simulated view of an air filter CFD without fairings disposed therein.

Fig. 6 is a CFD simulation of an air filter in an embodiment of the present application.

Reference numerals illustrate:

100. a filter box; 100a, an air inlet; 100b, an air outlet; 110. a first case; 111. a cover body; 112. a housing; 120. a second case; 130. a filter assembly; 131. a mounting plate; 1310. a peripheral wall; 132. a filter element; 200. a protective cover; 210. a grille; 211. a grid bar; 300. an air inlet pipe; 300a, an air inlet end; 300b, an air outlet end; 400. a rectifying member; 410. a ring portion; 420. an extension.

Detailed Description

In order to make the above objects, features and advantages of the present application more comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. This application is, however, susceptible of embodiment in many other forms than those described herein and similar modifications can be made by those skilled in the art without departing from the spirit of the application, and therefore the application is not to be limited to the specific embodiments disclosed below.

In the description of the present application, it should be understood that, if there are terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., these terms refer to the orientation or positional relationship based on the drawings, which are merely for convenience of description and simplification of description, and do not indicate or imply that the apparatus or element referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present application.

Furthermore, the terms "first," "second," and the like, if any, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the terms "plurality" and "a plurality" if any, mean at least two, such as two, three, etc., unless specifically defined otherwise.

In this application, unless explicitly stated and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly. For example, the two parts can be fixedly connected, detachably connected or integrated; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art as the case may be.

In this application, unless expressly stated or limited otherwise, the meaning of a first feature being "on" or "off" a second feature, and the like, is that the first and second features are either in direct contact or in indirect contact through an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

Referring to fig. 1, 2 and 3, an air filter according to an embodiment of the present application includes a filter box 100, a protective cover 200, an air inlet pipe 300 and a rectifying member 400. The filter box 100 is provided with an air inlet 100a and an air outlet 100b. The air inlet pipe 300 comprises an air inlet end 300a and an air outlet end 300b, and the air inlet pipe 300 penetrates through the air inlet 100a, so that the air inlet end 300a is positioned outside the filter box 100, and the air outlet end 300b is positioned inside the filter box 100. The protective cover 200 is connected to the air inlet pipe 300 and forms a protective chamber, and the air inlet end 300a is located in the protective chamber. The rectifying member 400 includes a ring portion 410 and an extension portion 420, the ring portion 410 is disposed around the outer side of the air inlet end 300a, the extension portion 420 is disposed around the outer side of the ring portion 410, and the extension portion 420 protrudes from an end face of the ring portion 410 facing the air outlet end 300 b.

According to the air filter provided by the application, the protective cover 200 is arranged on the filter box 100 to form the protective cavity, impurities such as liquid water and dust in air can be prevented from entering the air filter, the rectifying piece 400 with the annular part 410 and the extending part 420 is arranged on the air inlet end 300a of the air inlet pipe 300 in the protective cavity, and the air can be effectively prevented from flowing in disorder when entering the air inlet pipe 300 from the air inlet end 300a, so that air circulation is smoother, the air inlet efficiency of the air entering the filter box 100 from the air inlet 100a can be increased, and the improvement of the engine performance is finally realized.

In an exemplary embodiment, the air filter illustrated in fig. 2 and 3 is described below: the protection cover 200 is disposed at the upper left side of the filter box 100, and the top surface of the protection cover 200 is substantially on the same plane as the top surface of the filter box 100, so that the entire air filter has an approximately rectangular parallelepiped shape. The right side of the protection cover 200 is provided with a through hole corresponding to the air inlet 100a, the air inlet 300 is penetrated through the through hole and the air inlet 100a in the left-right direction to communicate the protection cavity with the filter box 100, and the protection cover 200 is sleeved on the outer circumferential side of the air inlet 300, which can be understood that the protection cover 200 is a component independent of the filter box 100. In other embodiments, it is also understood that the protective cover 200 is tightly adhered or integrally formed with the filter box 100. It can be appreciated that the filter box 100 is divided into an upper layer structure and a lower layer structure, the air inlet 100a is positioned at the left side of the upper layer of the filter box 100, the air outlet 100b is arranged at the right side of the lower layer of the filter box 100, and air can be filtered in the filter box 100 in the process that air flows from the air inlet 100a to the air outlet 100b. The air outlet 100b is provided with an air outlet pipe in a penetrating way so as to guide out the air filtered in the filter box 100 to the outside of the filter box 100.

The air inlet pipe 300 is a circular pipe, the left end of the circular pipe is an air inlet end 300a, the right end of the circular pipe is an air outlet end 300b, the rectifying piece 400 is connected with the air inlet pipe 300, and the rectifying piece 400 and the air inlet pipe 300 can be integrally formed, and the rectifying piece 400 can be fixedly connected with the air inlet pipe 300 in a screwing, bonding, screw mounting and other modes.

In some embodiments, referring to fig. 3 and 4, the rectifying member 400 includes a ring portion 410 and an extension portion 420, where the ring portion 410 is approximately circular, and the extension portion 420 is disposed on an outer edge of an end surface of the ring portion 410 near the air outlet end 300b, so that the whole rectifying member 400 has a structure similar to a barb, and the extension portion 420 may be understood to be integrally formed with the ring portion 410, or may be understood to be a circular ring formed by the ring portion 410 and the extension portion 420, and the extension portion 420 is fixedly connected with the ring portion 410 through a clamping or bonding manner.

Referring to fig. 5 and 6, fig. 5 is a CFD simulation diagram of the air intake pipe 300 without the rectifier 400 with the barb structure, fig. 6 is a CFD simulation diagram of the air filter in the embodiment of the present application, the white area of the approximate triangle corresponding to the air intake pipe 300 is a core flow, the gray multi-layer area on the edge of the white area is a turbulence, and according to the CFD simulation result, after the rectifier 400 is set, the area of the core flow in fig. 6 is significantly larger than the area of the core flow in fig. 5. Therefore, by providing the rectifying member 400 having the ring portion 410 and the extension portion 420, the development of turbulent flow in the air inlet pipe 300 is effectively suppressed, the area of core flow is enlarged, the airflow distribution of the whole pipe section in the air inlet pipe 300 is more uniform, the airflow obviously circulates more smoothly, and the air inlet efficiency of the air inlet pipe 300 is improved. The material of the extension 420, the ring 410, and the intake pipe 300 may be the same or different.

Illustratively, the extension 420, the ring 410, and the air inlet tube 300 are all plastic or all metal. Illustratively, one of the extending portion 420, the ring portion 410 and the air inlet pipe 300 is made of plastic, and the other is made of metal, and the remaining material is not limited herein.

In some embodiments, the extension 420 is integrally formed with the ring portion 410 and the air inlet pipe 300, and the barb-like structure formed by the extension 420 and the ring portion 410 is easy to form and release in mass production, thereby reducing the cost. Thus, by adopting the air filter according to the embodiment of the present application, not only the intake efficiency of the intake pipe 300 can be improved, but also the cost can be saved.

Referring to fig. 2 and 3, in some embodiments, the filter box 100 includes a first box 110, a second box 120, and a filter assembly 130, the air inlet 100a is disposed on the first box 110, the air outlet 100b is disposed on the second box 120, the first box 110 and the second box 120 are connected to form a receiving space together, and the filter assembly 130 is disposed in the receiving space. Through setting up in first box 110 and second box 120 respectively setting up air inlet 100a and gas outlet 100b, and first box 110 and second box 120 form accommodation space to set up filter assembly 130 in accommodation space, can make the air current get into filter box 100 through air inlet 100a, leave filter box 100 through gas outlet 100b after the filtration of filter assembly 130.

The first case 110 and the second case 120 are half-closed cases with one open surface, wherein the first case 110 has no bottom cover, the second case 120 has no top cover, and four sidewalls of the first case 110 and the second case 120 are aligned to form a receiving space after the first case 110 and the second case 120 are assembled by up-down splicing. The filter assembly 130 is disposed in the receiving space formed by the first casing 110 and the second casing 120, and supplies air flow. The air inlet 100a is disposed at the left side of the first case 110, the air outlet 100b is disposed at the right side of the second case 120, and after the air enters the first case 110 through the protection cavity and the air inlet 100a, the air enters the second case 120 through the filtering component 130 to remove impurities, and finally flows out of the air outlet 100b and enters the engine (not shown).

In some embodiments, the first case 110 includes a cover 111 and a housing 112 that are connected to each other, the cover 111 is disposed on the filter assembly 130, the housing 112 is disposed on a side of the cover 111 facing away from the filter assembly 130, a length of the housing 112 is smaller than a length of the cover 111, such that one end of the first case 110 is formed with a recess, the protection cover 200 is disposed on the recess, the air inlet 100a is formed on a sidewall of the housing 112 facing the protection cover 200, and the air outlet 100b is located on a sidewall of one end of the second case 120 facing away from the recess. By providing the cover 112 having a length smaller than the cover 111 on the cover 111 to form the recess, the protection cover 200 can be more firmly provided; on the other hand, the air inlet 110a is disposed on the side wall of the housing 112, and the air outlet 100b is disposed on the side wall of the end of the second casing 120 facing away from the recess, so that the diffusion distance of the air flow entering the first casing 110 through the air inlet 110a is reduced, and the air speed and the air loss are reduced.

With continued reference to fig. 2 and 3, illustratively, the cover 111 is disposed over the filter assembly 130, and the cover 111 is the same length and width as the second housing 120 and the filter assembly 130. The cover 112 is formed to extend upward from three sides of the cover 111, and it is understood that the length of the cover 112 is smaller than the length of the cover 111 such that a left side wall of the cover 112 is formed on the top surface of the cover 111. The air inlet 100a is provided on the left side wall of the housing 112, and the air outlet 100b is provided on the right side wall of the second casing 120, opposite to the air inlet 100a, so that the flow direction of the air flow is more reasonable. By setting the shroud length to be smaller than the length of the cover, air is diffused in the shroud 112 having a shorter length after entering the first casing 110 through the air inlet pipe 300, reducing wind speed and wind volume loss, and further suppressing generation of turbulence. On the other hand, the protection cover 200 is disposed on the concave portion, so as to prevent the protection cover 200 from extending out of the first case 110 and being easily collided to be separated from the air inlet pipe 300.

In this embodiment, the shell 112 and the cover 111 are integrally formed, so that the installation is convenient, and no barrier exists between the upper and lower parts of the shell 112 and the cover 111. In other embodiments, the cover 111 and the housing 112 may be two interconnected housings, and a through hole is formed in a top wall of the cover 111 below the housing 112 to communicate the cover 111 and the housing 112, which also has an effect of allowing air to flow from the air inlet 100a to the filter assembly 130.

In some embodiments, the sidewall of the housing 112 provided with the air inlet 100a is inclined toward a side away from the protection cover 200 with respect to the cover 111. By providing the side walls with an inclined configuration, the first housing 110 has a draft angle that is easier to demold during production.

As shown in fig. 3, the side wall of the housing 112 opposite to the air inlet 100a is disposed in the vertical direction, and the side wall of the housing 112 on which the air inlet 100a is disposed forms an angle with the vertical direction, and is inclined toward the side away from the protection cover 200 in the direction away from the cover 111, for example. In this embodiment, the first case 110 is formed by integrally molding the shell 112 and the cover 111, the first case 110 is made of plastic, and the inclined side walls are inclined to form a demolding angle, so that the first case 110 can be easily demolded when the first case 110 is mass-produced by using a mold, and the molding quality of the first case 110 can be improved.

Referring to fig. 3, in some embodiments, the filter assembly 130 includes a mounting plate 131 and a filter cartridge 132, the mounting plate 131 being provided with a mounting groove having a peripheral wall 1310 protruding toward the first and second housings 110 and 120, respectively, and the filter cartridge 132 being disposed in the mounting groove. By extending the peripheral wall 1310 of the mounting groove toward the first and second cases 110 and 120, respectively, the thickness of the mountable filter cartridge 132 is increased, and the filtering effect is improved.

Illustratively, the mounting plate 131 is approximately a rectangular plate having the same length and width as the cover 111 and the first housing 110. The mounting groove is an approximately rectangular through hole, wherein the peripheral wall 1310 extends upward and deep into the cover 111 at the upper side of the mounting plate 131, and the peripheral wall 1310 extends downward and deep into the second casing 120 at the lower side of the mounting plate 131. By providing the peripheral wall 1310 in a form extending to both sides, the filter element 132 having a larger thickness can be installed in the installation groove, and a better filtering effect can be provided without increasing the thickness of the installation plate 131 and without affecting the volumes of the first and second cases 110 and 120. The greater the length that the peripheral wall 1310 extends upward or downward, the greater the thickness of the mountable filter cartridge 132. Therefore, the mounting plate 131 having the peripheral wall 1310 of a specific extension length may be selected according to the actually required filtering effect to mount different filter cartridges 132 to meet the need, improving the practicality of the air filter.

In some embodiments, the protective cover 200 is provided with a vent, opposite the air inlet 100a, on which a grill 210 is provided.

Referring to fig. 2, the vent is illustratively provided on a sidewall of the protective cover 200, which is far from the air inlet 100a and opposite to the air inlet 100a, the air inlet 100a is approximately rectangular, and four corners of the rectangle are rounded, so that foreign matters such as dust are effectively prevented from accumulating on the four corners of the air inlet 100 a. The vent is provided with a grill 210, and the grill 210 includes a plurality of grill strips 211, which prevent some relatively large foreign objects, such as sand, tree branches, etc., from entering the protective cover 200. In the exemplary embodiment, grill 210 is integrally formed with protective cover 200 and is more convenient to install. In other embodiments, it can be understood that the grille 210 is detachably mounted on the protective cover 200 and covers the air vent, so that the grille 210 can be replaced according to the actual usage environment, for example, the grille 210 with wider or narrower spacing between the grille strips 211 is selected, or the grille 210 made of different materials, such as diamond mesh, is selected to meet the requirements of different environmental conditions, and the applicability of the protective cover 200 to different environmental conditions is improved.

In some embodiments, the grid 210 includes grid bars 211 disposed in a longitudinal direction. The longitudinal arrangement of the grills 211 serves to guide the rainwater to flow downward without being accumulated on the vent, thereby reducing the amount of water entering the tank 100.

With continued reference to fig. 2, illustratively, six grills 211 are disposed on the vent, the six grills 211 are parallel to each other, and the upper ends of the remaining grills 211 are connected to the top side edge of the vent, and the lower ends of the six grills 211 are connected to the bottom side edge of the vent. In this design, when the air filter works in a raining environment, rainwater flows downwards from the top side edge of the vent hole along the length direction of the grill 211 from the top end of the grill 211 under the action of gravity. Compared with the grid bars in other shapes such as the cross bars or the cross bars which are transversely arranged, the grid bars 211 which are longitudinally arranged can prevent water from accumulating on the grid bars 211, reduce the residence time of water in the air vent and the retention quantity of water in the air vent, further reduce the load of the filter element 132 on the water and prolong the service life of the filter element 132. On the other hand, the rainwater is left from top to bottom along the longitudinal grid bars 211, which can also play a cleaning role on the grid bars 211, delay the accumulation rate of dust and other impurities on the air vent, and is not easy to influence the air inflow of the filter assembly 130.

In some embodiments, the air inlet 300 is disposed at an incline relative to the mounting plate 131, with the air inlet end 300a being spaced from the mounting plate 131 a greater distance than the air outlet end 300 b. This may allow an end of the air inlet pipe 300 remote from the fairing 400 to approach the filter assembly 130. Taking the air inlet pipe 300 shown in fig. 3 as an example, the air inlet pipe 300 is inclined downwards in the left-to-right direction, so that the distance between the air outlet end 300b and the filter element 132 is shortened, the air flow in the first box 110 is more reasonable, and the flow velocity loss of the air flow in the first box 110 is reduced.

In some embodiments, the outside edges of the filter box 100 are chamfered. Referring to fig. 1 and 2, in an exemplary embodiment, outer edges of the first and second cases 110 and 120 each form a rounded chamfer, and other edges of the protective cover 200 except for edges corresponding to the first case 110 also form a rounded chamfer. Chamfering is formed at the outer edges of the first and second cases 110 and 120 and the protective cover 200, which can prevent the skin of the human body from being scratched, and is more convenient to install.

The present application also relates to a motorcycle (not shown) comprising an engine (not shown), a body (not shown) and an air filter as described above. Illustratively, the body of the motorcycle includes a seat assembly with an air filter mounted beneath the seat assembly and between the two wheels. The air outlet 100b of the air filter is provided with an air outlet pipe which communicates with the engine. Therefore, air enters the protection cavity through the air vent of the protection cover 200, the air enters the filter box 100 after the air inlet efficiency is improved through the rectification function of the rectification piece 400, and the air enters the engine through the air outlet pipe after being filtered by the filter element 132. The rectifying piece 400 improves the air inlet efficiency of the air filter, and the protective cover 200 and the filter element 132 can further enable air to be purer, so that the engine work is facilitated, the performance of the engine is effectively improved, and the maintenance cost is reduced, so that the motorcycle has a competitive advantage in the market.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples only represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the claims. It should be noted that it would be apparent to those skilled in the art that various modifications and improvements could be made without departing from the spirit of the present application, which would be within the scope of the present application. Accordingly, the scope of protection of the present application is to be determined by the claims appended hereto.

Claims (10)

1. An air filter, the air filter comprising:

the filter box is provided with an air inlet and an air outlet;

the air inlet pipe comprises an air inlet end and an air outlet end, and the air inlet pipe penetrates through the air inlet, so that the air inlet end is positioned outside the filter box, and the air outlet end is positioned in the filter box;

the protective cover is connected with the air inlet pipe and forms a protective cavity, and the air inlet end is positioned in the protective cavity;

the rectifying piece comprises a ring part and an extension part, wherein the ring part is arranged around the outer side of the air inlet end, the extension part is arranged around the outer side of the ring part, and the extension part protrudes out of the end face of the ring part, which faces towards the side where the air outlet end is located.

2. The air filter of claim 1, wherein the fairing is integrally formed with the air inlet duct.

3. The air filter of claim 1, wherein the filter housing comprises a first housing, a second housing, and a filter assembly, the air inlet is disposed on the first housing, the air outlet is disposed on the second housing, and the first housing and the second housing are connected to form a housing space together, and the filter assembly is disposed in the housing space.

4. The air filter according to claim 3, wherein the first case includes a cover body and a housing which are communicated with each other, the cover body is covered on the filter assembly, the housing is provided on a side of the cover body facing away from the filter assembly, a length of the housing is smaller than a length of the cover body, so that one end of the first case is formed with a recess portion, the protection cover is provided in the recess portion, the air inlet is formed on a side wall of the housing facing the protection cover, and the air outlet is provided on a side wall of one end of the second case facing away from the recess portion.

5. The air filter according to claim 4, wherein a side wall of the housing provided with the air inlet is inclined toward a side away from the protection cover with respect to the cover.

6. An air filter according to claim 3, wherein the filter assembly comprises a mounting plate and a filter element, the mounting plate is provided with a mounting groove, two ends of a peripheral wall of the mounting groove extend toward the first box body and the second box body respectively in a direction perpendicular to the mounting plate, and the filter element is arranged in the mounting groove.

7. The air filter of claim 6, wherein the air inlet tube is disposed at an incline relative to the mounting plate, and the air inlet end is spaced from the mounting plate a greater distance than the air outlet end.

8. An air filter according to claim 1, wherein the protective cover is provided with a vent opening opposite the air inlet, and a grille is provided on the vent opening.

9. The air filter of claim 8, wherein the grille includes a plurality of louvers having ends connected to a top edge of the vent and a bottom edge of the vent, respectively.

10. A motorcycle comprising an engine, a vehicle body, and the air filter according to any one of claims 1 to 9, the air filter being provided on the vehicle body, the air outlet communicating with the engine.