AIR CLEANER

An air cleaner includes a case having an internal space, a filter element capable of partitioning the internal space into first and second spaces, an intake port that introduces an air into the first space therethrough, an exhaust port that discharges an air from the second space, and at least one baffle part projecting toward the filter element from an inner surface of the case. The baffle part diffuses the air introduced into the first space and introduces the air to the filter element. The baffle part includes a first baffle part extending along an extending surface of the filter element. The first baffle part is curved so as to be away from a hypothetical straight line connecting the intake port and the exhaust port as the first baffle part extends from the intake port toward the exhaust port as viewed in a direction perpendicular to the extending surface.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2019-157977 filed Aug. 30, 2019, the entire contents of which are hereby incorporated by reference.

BACKGROUND

Technical Field

This disclosure relates to an air cleaner for filtering and purifying air, or a structure thereof. In particular, this disclosure relates to an air cleaner for filtering and purifying the air to be fed to an internal combustion engine, or a structure thereof.

Related Art

Air cleaners which filter out dust from the air to purify the air are widely used in various applications, for example, internal combustion engines for motor vehicles such as motor cars and motorcycles, air conditioners, fuel cells, and air cooling systems for cells and electronic circuits. The air cleaners are to collect fine particles with high efficiency according to each application and are also to have characteristics that withstand a long-term use with less clogging.

A known example of air cleaners for automotive internal combustion engines is an air cleaner having a filter material in the form of a flat plate (a flat element). For example, Japanese Patent Application Laid-Open Publication No. 2000-346687 (JP 2000-346687 A) discloses an air cleaner having a filter material by which air is filtered. The air cleaner described in JP 2000-346687 A includes a cleaner element, a cleaner case that accommodates the cleaner element, and a diffusion plate that divides an intake flow. The inside of the cleaner case is partitioned by the cleaner element into a dirty-side space upstream of air flow and a clean-side space downstream of air flow. The dirty-side space is provided with an intake pipe coupled thereto, and the clean-side space is provided with an outlet pipe coupled thereto. The diffusion plate is disposed in the dirty-side space to divide an intake flow introduced through the intake pipe and guide the divided air to the cleaner element. The air that passed through the cleaner element flows out of the outlet pipe.

SUMMARY

However, the air cleaner described in JP 2000-346687 A has the diffusion plate extending in a direction intersecting with the direction (surface direction) in which the cleaner element extends. Thus, for example, when the distance between the cleaner element and an end of the diffusion plate extending toward the cleaner element is short, the air introduced through the intake pipe may be not guided homogeneously or uniformly to the cleaner element, resulting in inhomogeneous contamination of the cleaner element with dust or inhomogeneous dust distribution on the cleaner element.

The inventors made intensive studies to solve the above problem and finally found the following: a baffle part (or an air-guiding part) is provided in a specific configuration, such as a configuration curved in a direction away from a hypothetical straight line connecting an intake port and an exhaust port or a configuration radially extending from near the intake port, on a surface of a case facing an extending surface of a filter element, and such a baffle part enables an air flow from the intake port to be diffused in a first space homogeneously or uniformly in a direction of the filter element and filtered and then to be discharged from a second space. That is, an air cleaner according to one aspect of this disclosure includes a case having an internal space, a filter element capable of partitioning the internal space into a first space and a second space, an intake port that introduces an air into the first space therethrough, an exhaust port that discharges an air from the second space, and at least one baffle part that projects or protrudes toward the filter element from an inner surface of the case and diffuses the air introduced into the first space and introduces the air to the filter element. The baffle part includes a first baffle part extending along an extending surface of the filter element. The first baffle part is curved so as to be away from a hypothetical straight line connecting the intake port and the exhaust port as the first baffle part extends from the intake port toward the exhaust port as viewed in a direction perpendicular to the extending surface.

The at least one baffle part may pass through a center of the filter element as viewed in the direction perpendicular to the extending surface.

The first baffle part may have a plurality of baffle bodies projecting from the inner surface of the case. The baffle bodies may be arranged so that a distance between adjacent two baffle bodies is larger toward the exhaust port from the intake port as viewed in the direction perpendicular to the extending surface.

The first baffle part may have a plurality of baffle bodies projecting from the inner surface of the case. As viewed in the direction perpendicular to the extending surface, the baffle body farthest of the baffle bodies away from the straight line may have a curvature larger than the baffle body nearest the straight line does.

The first baffle part may have a plurality of baffle bodies projecting from the inner surface of the case. As viewed in the direction perpendicular to the extending surface, a baffle body farther of the baffle bodies away from the straight line may have a larger curvature.

The first baffle part may have a first end (hereinafter may be referred to as a proximal end) close to or near the intake port and a second end (hereinafter may be referred to as a distal end) opposite to the first end. The first baffle part may have a curvature increased monotonically toward the second end from the first end.

The baffle part may further include a second baffle part. The second baffle part may be disposed linearly in a direction intersecting with an opening surface of the intake port as viewed in the direction perpendicular to the extending surface of the filter element.

The straight line connecting the intake port and the exhaust port may be offset from a center of the filter element as viewed in the direction perpendicular to the extending surface.

DESCRIPTION OF EMBODIMENTS

Hereinafter, an air cleaner according to embodiments of this disclosure will be described in detail with reference to the drawings. The air cleaner is used for, for example, a motor vehicle including a motor car and filters air to be supplied to an internal combustion engine of the motor vehicle. Hereinafter, the same reference numerals are used to refer to the same, similar or corresponding members or parts or components. As used herein, the term “substantially” refers to the complete or nearly complete extent or degree of an action, characteristic, property, state, structure, item, or result. As an arbitrary example, an object that is “substantially” enclosed would mean that the object is either completely enclosed or nearly completely enclosed. For example, the term “substantially parallel” means “parallel” or “substantially parallel”.

First Embodiment

With reference toFIG. 1toFIG. 3, an air cleaner100according to a first embodiment will be described.FIG. 1is an exploded perspective view showing the air cleaner100according to the first embodiment.FIG. 2is a plan view showing an upstream case11according to the first embodiment. InFIG. 2, a narrow long dashed double-short dashed line shows an exhaust pipe31and an exhaust port32, and a wide long dashed double-short dashed line shows a filter element4.FIG. 3is a cross-sectional view showing a baffle body50and the upstream case11shown inFIG. 2. Specifically,FIG. 3is a cross-sectional view taken along line III-III ofFIG. 2. A direction of an arrow D1inFIG. 3indicates a projecting direction.

As shown inFIG. 1, the air cleaner100includes a case1having an internal space1S, and a filter element4capable of partitioning the internal space1S into an upstream first space11S and a downstream second space12S. The filter element4has an extending surface P4(a main surface). The extending surface P4includes a direction in which the filter element4extends.

The case1includes the upstream case11and a downstream case12. The first space11S is a space defined by the upstream case11and the filter element4. The second space12S is a space defined by the downstream case12and the filter element4.

The air cleaner100further includes an intake part2that introduces air into the first space11S, and an exhaust part3for discharging the air taken in the internal space1S via the intake part2to the outside of the air cleaner100. The air introduced into the first space11S passes through the filter element4to be introduced into the second space12S. The air to be introduced into the second space12S is filtered by the filter element4. That is, the filter element4removes dust from the air. The air introduced into the second space12S is discharged outside the case1through the exhaust part3. Thus, clean air is discharged outside the air cleaner100.

Hereinafter, according to the configuration shown inFIG. 1, the side on which the upstream case11is located in the air cleaner100is referred to as a “lower side”, the side opposite to the “lower side” is described as an “upper side”, the side on which the intake part2is provided in the air cleaner100is referred to as a “front side”, the side opposite to the “front side” is described as a “rear side”, the left side viewed from the front side of the air cleaner100is described as a “left side”, and the side opposite to the “left side” is described as a “right side.” However, these definitions do not limit the orientation in use of the air cleaner100. Hereinafter, the left-right direction may be referred to as the “width direction of the air cleaner100”, and the upper-lower direction may be referred to as the “height direction of the air cleaner100.”

The upstream case11and the downstream case12can each be produced by injection molding of a thermoplastic resin representatively. Examples of the thermoplastic resin may include a polyester resin, a polypropylene resin, and a polyamide resin. If necessary, at least one of the upstream case11and the downstream case12may be integrally formed or molded with a support stay (not shown).

The upstream case11is box-shaped being substantially rectangular in a plan view, having an opening toward the downstream case12(or upward). The upstream case11has a bottom wall111having a bottom surface (inner bottom surface)111aand facing the downstream case12, a first side wall112rising from a peripheral edge of the bottom wall111, and a first flange113extending outward from an upper edge of the first side wall112. The first side wall112has a front wall112fprovided with the intake part2, and a first rear wall112bfacing the front wall112fin the front-rear direction.

The intake part2has an intake pipe21projecting outward from the case1, and an intake port22allowing the intake pipe21and the first space11S to communicate with each other to introduce air into the first space11S. In this embodiment, the intake pipe21extends in the horizontal direction or in substantially parallel with the bottom surface111a. To the intake pipe21, representatively, an upstream intake duct (not shown) or a silencer (not shown) is coupled.

As shown inFIG. 2, the intake port22is disposed at a position deviated to one side from the center of the front wall112f. That is, the intake port22is offset from the center of the upstream case11in the width direction. Specifically, the intake pipe21(the central axis m1of the intake pipe21) and the intake port22are offset to the left from the center of the front wall112fand are offset from the center X of the filter element4. The center X of the filter element4may be referred to as the center X of the extending surface P4of the filter element4provided in the internal space1S. Hereinafter, the direction in which the intake port22is offset is referred to as a “first offset direction”. In this embodiment, the first offset direction is a direction from the right to the left.

As shown inFIG. 1, the downstream case12is box-shaped being substantially rectangular in a plan view, having an opening toward the upstream case11(or downward). The downstream case12has a top wall121having a top surface facing the upstream case11, a second side wall122extending downward from a peripheral edge of the top wall121to surround the top wall121, and a second flange123extending outward from a lower edge of the second side wall122.

The second side wall122has a second rear wall122bconstituting a back surface of the downstream case12. In an assembled state of the air cleaner100, the second rear wall122band the first rear wall112bare in the same plane. That is, a plane containing the second rear wall122band the first rear wall112bfaces the front wall112f. And the second rear wall122bfaces the front wall112f, being different in height position from the front wall112f.

The exhaust part3has an exhaust pipe31projecting outward from the case1, and an exhaust port32allowing the exhaust pipe31and the second space12S to communicate with each other to discharge air from the second space12S to the outside of the case1. In this embodiment, the exhaust pipe31extends in the horizontal direction or in substantially parallel with the top surface of the top wall121. To the exhaust pipe31, representatively, a part such as a downstream duct (not shown) or a throttle body (not shown) is coupled. The upstream intake duct or the silencer is coupled to the intake pipe21and the downstream duct or the throttle body is coupled to the exhaust pipe31, forming an air intake path to an internal combustion engine.

In this embodiment, the exhaust port32faces the intake port22, being different in height position from the intake port22in an assembled state of the air cleaner100. Specifically, as shown inFIG. 2, the exhaust port32is arranged substantially on a hypothetical straight line extending from the central axis m1of the intake pipe21(intake port22) in a plan view or as viewed from a direction perpendicular to the extending direction of the filter element4. That is, a hypothetical straight line n1connecting the intake port22(the central axis m1of the intake pipe21) and the exhaust port32(the central axis m2of the exhaust pipe31) is coaxial with the central axis m1of the intake pipe21. Thus, the straight line n1is offset from the center X of the filter element4. Hereinafter, the direction in which the straight line n1is offset is referred to as a “second offset direction”. In this embodiment, the second offset direction is a direction from the right to the left and agrees with the first offset direction.

As shown inFIG. 1, the filter element4is a flat member being substantially rectangular in a plan view. The filter element4has outside dimensions in a plan view substantially the same as the outside dimensions of the upstream case11and those of the downstream case12. The filter element4is supported between the upstream case11(the first flange113) and the downstream case12(the second flange123) so as to be substantially parallel with the bottom wall111(the bottom surface11a) of the upstream case11. That is, the filter element4(the extending surface P4) extends in a substantially parallel direction with respect to the central axis m1of the intake pipe21(seeFIG. 2) or a direction of an air flow drawn from the intake port22. In this embodiment, the intake pipe21is configured to allow air to flow in a direction substantially parallel with the extending surface P4of the filter element4at or near the intake port22. The intake pipe21, however, may or may not be configured to allow air to flow in a direction substantially parallel with the extending surface P4of the filter element4at or near the intake port22.

The filter element4has a filter material41and a seal member42. The filter material41is a flat member being substantially rectangular in a plan view. The seal member42is disposed to surround the periphery of the filter material41in order to prevent leakage of air from a gap between the upstream case11and the downstream case12. The filter element4may have a frame capable of supporting the filter material41by surrounding the filter material41.

The filter material41representatively includes a pleated paper filter or a pleated nonwoven fabric. Alternatively, the filter material41may be an open-cell resin foam or sponge having a flat form. The filter material41may be a viscous filter material impregnated with oil or others, or may be a dry filter material having no impregnated oil or others.

As shown inFIG. 1andFIG. 2, the air cleaner100further includes a baffle part5that diffuses the air flowing in the first space11S to introduce the air flow to the filter element4. The baffle part5includes a plurality of baffle bodies50disposed on the bottom surface111aof the upstream case11. The baffle bodies50are integrally formed or molded with the upstream case11. For example, each one of the baffle bodies50is a plate member having a rib form or a fin form or a member having a bead form.

As shown inFIG. 1, the baffle body50projects from the bottom surface111a(that is, the surface facing the filter element4in the case1) toward the filter element4(the extending surface P4). Hereinafter, the direction in which the baffle body50projects may be referred to as a “projecting direction”. The projecting direction representatively corresponds to a direction removing a core for forming the baffle body50and the inner periphery of the case1in forming the upstream case11by injection molding.

The baffle body50extends along the extending surface P4. In this embodiment, the baffle body50continuously extends to the first side wall112along the extending surface P4.

As shown inFIG. 2, the baffle body50has a first end (proximal end or upstream end)50A close to or near the intake port22and a second end (distal end or downstream end)50B opposite to the first end50A. The second end50B is connected to the first side wall112. The second end50B of the baffle body50, however, may or may not be connected to the first side wall112. That is, there may be a distance between the baffle body50and the inner surface of the first side wall112.

In this embodiment, the baffle bodies50are arranged in a configuration in which each first end50A faces the intake port22. The baffle bodies50are arranged at intervals with each other in the left-right direction.

The baffle bodies50are arranged to extend radially from near the intake port22as viewed in a direction perpendicular to the extending surface P4. Specifically, the baffle bodies50are arranged radially or in a radial pattern so that a distance between second ends50B of adjacent two baffle bodies50is longer than a distance between first ends50A thereof. That is, the baffle bodies50are arranged radially so that distances between adjacent two baffle bodies are increased from the intake port toward the exhaust port.

The baffle bodies50include three curved baffle bodies51and a linear baffle body52. The three curved baffle bodies51include a first curved baffle body511, a second curved baffle body512, and a third curved baffle body513. The curved baffle body51constitutes a first baffle part. The linear baffle body52constitutes a second baffle part.

Each one of the curved baffle bodies51is substantially arc-shaped in a plan view and is curved in a direction opposite to the second offset direction. The curved baffle body51is curved so as to be away from the straight line n1connecting the intake port and the exhaust port as the baffle body extends from the intake port toward the exhaust port as viewed in the direction perpendicular to the extending surface P4. That is, as viewed in the direction perpendicular to the extending surface P4of the filter element4, the curved baffle body51is curved in a direction away from the straight line n1in a direction from the first end50A toward the second end50B, i.e., is curved from the left to the right. In this embodiment, the first curved baffle body511, the second curved baffle body512, and the third curved baffle body513each have a constant curvature.

The baffle body51farthest away from the straight line n1has a curvature larger than the baffle body51nearest the straight line n1has. Specifically, the third curved baffle body513has a curvature larger than the first curved baffle body511has. The curved baffle bodies51are configured so that a baffle body farther of the baffle bodies away from the straight line n1has a larger curvature. Specifically, the curvature of each baffle body51is set so that a baffle body farther away from the straight line n1has a larger curvature gradually. In this embodiment, the ascending order in curvature is the first curved baffle body511, the second curved baffle body512, and the third curved baffle body513, and the increasing rate in curvature is constant. That is, the curvature gradually increases in the ascending order of the first curved baffle body511, the second curved baffle body512, and the third curved baffle body513.

The first curved baffle body511and the second curved baffle body512each extend from the position facing the intake port22to the first rear wall112bof the upstream case11. In this embodiment, the first curved baffle body511extends to a position corresponding to the exhaust port32in the first rear wall112bof the upstream case11. And the second curved baffle body512extends to or near the right corner of the first rear wall112bof upstream case11in substantially parallel with a diagonal of the filter element4. The third curved baffle body513extends from the position facing the intake port22to a right-side wall112rof the upstream case11. Specifically, the third curved baffle body513extends to or near the center of the right-side wall112rof the upstream case11.

The linear baffle body52is positioned downstream in the first offset direction among the baffle bodies50. Specifically, the linear baffle body52is disposed on the left side of the first curved baffle body511. The linear baffle body52extends substantially linearly in a direction intersecting with the opening surface of the intake port22as viewed in the direction perpendicular to the extending surface P4of the filter element4; where the opening surface of the intake port22extends in the left-right direction and the upper-lower direction. Specifically, the linear baffle body52is across the straight line n1at a slight angle.

As shown inFIG. 3, the baffle body50is a solid member and projects from the bottom surface111a(the bottom wall111) toward the filter element4. The baffle body50may have a height, or a length projecting from the bottom surface111a, adjusted to allow an air from the intake port22to smoothly flow along the baffle body50. In this embodiment, the height of the baffle body50and the distance between the baffle body50and the filter element4are constant along the longitudinal direction of the baffle body.

The baffle body50has a guide surface501as either side. The guide surface501is substantially parallel with the projecting direction D1. The air flowing from the intake port22into the upstream case11flows along the guide surface, being diffused over the space (the first space11S) surrounded with the guide surface501of the baffle body50, the bottom surface11a, the first side wall112(seeFIG. 1), and/or others.

Hereinafter, with reference toFIG. 4andFIG. 5, the functions and effects of the air cleaner100according to the first embodiment will be described.

FIG. 4is a view schematically illustrating an air flow in an air cleaner200according to a reference example.FIG. 5is a view schematically illustrating an air flow in the air cleaner100according to the first embodiment. The air cleaner200shown inFIG. 4is different from the air cleaner100shown inFIG. 5in the lack of the baffle body50on the upstream case11.

As shown inFIG. 4, in the air cleaner200according to the reference example, a hypothetical straight line200nconnecting an intake port222and an exhaust port232is offset from a center200X of a filter element204. In the air cleaner200having such a configuration, an air flow from the intake port222tends to flow straightly along the straight line200nand tends to be biased to one side (or a side in which the straight line200nis offset) of the filter element204without diffusion. Thus, most of the air passes through a region of the filter element204overlapping or near the straight line200nin a plan view. This leads to a tendency to collect dust contained in the air locally in a shaded region200R inFIG. 4. The air cleaner200according to the reference example thus makes it difficult to uniformly use a filter material of the filter element204and difficult to allow dust to be homogeneously collected or distributed on the filter element204.

In the air cleaner200according to the reference example, the straight line200nconnecting the intake port222and the exhaust port232is offset from the center200X of the filter element204, and thus most of the air tends to flow straightly toward the exhaust port232. This phenomenon is also called short pass phenomenon of air flow. The short pass phenomenon causes the air flow to concentrate in a certain region of the filter element204, and dust locally accumulates at the certain region of the filter element204. This localized accumulation of dust may cause local deformation of the filter material41and/or dust leakage.

As shown inFIG. 5, the air cleaner100according to this embodiment is provided with the baffle body50that diffuses the air introduced from the intake port22into the first space11S, and the filter element4is used uniformly. This allows the filter element4to collect dust in a homogeneous distribution of dust.

As described with reference toFIG. 2, the air cleaner100has the curved baffle body51, having the first end50A positioned near the intake port22and being curved in a direction in which the second end50B is away from the central axis m1of the intake pipe21. Thus, the direction of the air flow introduced from the intake port22into the first space11S is changed or diverged to a direction away from the straight line n1. This results in diffusion of the air to a region away from the straight line n1in addition to a region overlapping or near the straight line n1of the filter element4in a plan view, as shown inFIG. 5. This allows collection of dust in a shaded region R shown inFIG. 5. The filter element4inFIG. 5thus can collect dust in a larger region compared with the filter element204shown inFIG. 4. This results in uniform use of the filter element4inFIG. 5compared with the configuration shown inFIG. 4and allows the filter element4to collect dust in a homogeneous distribution of dust.

Moreover, the diffusion of the air by the baffle part5prevents the air flow from concentrating in a certain region of the filter element4. This reduces the occurrence of short pass phenomenon compared with the air cleaner200according to the reference example shown inFIG. 4and prevents local deformation of the filter material41and/or dust leakage.

The first embodiment of this disclosure has been described above. According to the first embodiment, the air introduced into the first space11S is diffused by the baffle bodies50and is introduced to the filter element4. Thus, this prevents localized collection of dust in the filter element4. That is, the filter element4is used uniformly, and this allows the filter element4to collect dust in a homogeneous distribution of dust.

Moreover, the air cleaner described in JP 2000-346687 A, in which the opening surface of the intake port is disposed in substantially parallel with the extending direction of the filter element, that is, in which the central axis of the intake port is substantially perpendicular to the extending direction of the filter element, may have a long total height (or a large length in the upper-lower direction). In contrast, according to this embodiment, the extending surface P4of the filter element4intersects with the opening surface of the intake port22. Such a configuration makes the total height of the air cleaner100small. This allows a space-saving design of the air cleaner100and a reduced installation space of the air cleaner100. In some embodiments, the intake pipe21extends in substantially parallel with the extending surface P4of the filter element or the bottom surface11aof the case.

In this embodiment, the intake pipe21and the exhaust pipe31each project to the outside of the case1from a position offset with respect to the center in the width direction (or the left-right direction) of the case1. This improves a flexibility of layout design compatible to an installation space of the air cleaner100.

In this embodiment, the air is diffused and is guided or introduced to the filter element4, even in a case where the straight line n1connecting the intake port22and the exhaust port32is offset from the center of the width direction (or the left-right direction) of the case1. This allows the filter element4to collect dust in a homogeneous distribution of dust.

In this embodiment, at least one of the curved baffle bodies51is curved to pass through the substantial center X of the filter element4in a plan view. Such a baffle body50facilitates smooth flow of the air to the substantial center X of the filter element4and reduces or prevents stagnation of the air in the first space11S. Thus, in the first space11S, the air flow is smooth and is efficiently diffused, and this allows the filter element4to collect dust in a more homogeneous distribution of dust.

In this embodiment, the curved baffle bodies51are arranged radially so that distances between adjacent two baffle bodies are increased in a direction from the intake port22toward the exhaust port32. Such a configuration enables efficient diffusion of the air in the first space11S.

In this embodiment, the curved baffle bodies51are configured so that the baffle body51farthest away from the straight line n1(or the rightmost baffle body51) has a curvature (or curve) larger than the baffle body51nearest the straight line n1has. Such a configuration enables efficient diffusion of the air.

In this embodiment, the curved baffle bodies51are configured so that a baffle body51farther away from the straight line n1has a larger curvature (or curve). Such a configuration enables efficient diffusion of the air.

In this embodiment, the linear baffle body52is inclined to a direction opposite to the second offset direction as the linear baffle body52extends away from the intake port22in a plan view. Such a configuration reduces or prevents the air flow from going straight and allows uniform use of the filter element4.

In this embodiment, the guide surface501is disposed in substantially parallel with the projecting direction D1(seeFIG. 3). Such a configuration enables the air cleaner100to have a large gutter-shaped space (between adjacent baffle bodies50) where the air flows. This results in the air flowing smoothly along the guide surface501of the baffle body50. This enables efficient diffusion of the air.

As described with reference toFIG. 4, the short pass phenomenon occurs in the air cleaner200according to the reference example and may cause local deformation of the filter material. Alternatively, this may cause dust leakage. In contrast, according to this embodiment, the air flowing from the intake port22into first space11S is diffused. Thus, the filter material41is prevented from local deformation due to short pass phenomenon of the air flow, even in a case where the straight line n1connecting the intake port22and the exhaust port32is offset from the center of the width direction (or the left-right direction) of the case1. Moreover, dust leakage due to the short pass phenomenon of the air flow is also prevented.

In this embodiment, each one of the curved baffle bodies51has a constant curvature. Each one of the curved baffle bodies51may have a curvature gradually increased at greater distances from the straight line n1. For example, each one of the curved baffle bodies51has a curvature increased monotonically toward the second end50B from the first end50A. Near the intake port22(or near the first end50A), the air introduced into the first space11S may be diffused insufficiently. In a case where each one of the curved baffle bodies51has a curvature gradually increased at greater distances from the straight line n1, the direction of the air flow is gradually changed. This results in sufficient diffusion of the air. Moreover, in a case where each one of the curved baffle bodies51has a curvature gradually increased at greater distances from the straight line n1, such curved baffle bodies facilitate smooth flow of the air along each curved baffle body51. This results in more efficient diffusion of the air.

Each one of the curved baffle bodies51may have a sign inversion in the curvature or may be curved only in one direction without a sign inversion in the curvature, that is, may have a curvature with no inflection point. Alternatively, at least one of the curved baffle bodies51may have a linear portion. Such a configuration facilitates smooth flow of the air along each curved baffle body51. This results in more efficient diffusion of the air.

In this embodiment, the linear baffle body52is inclined so as to intersect with the straight line n1at or near the exhaust port. The linear baffle body52may be disposed linearly in substantially parallel with the left-hand or right-hand first side wall112of the upstream case11. Such a configuration also results in more efficient diffusion of the air.

In this embodiment, the linear baffle body52is across the straight line n1. The linear baffle body52may or may not be across the straight line n1.

In this embodiment, the upstream case11and the downstream case12each are substantially rectangular in a plan view. Each of the upstream case11and the downstream case12may have any form that enables the air introduced from the intake pipe21to be filtered by the filter element4and then discharged from the exhaust pipe31. For example, the forms of the upstream case11and the downstream case12may be substantially circular, substantially polygonal, or substantially elliptical in a plan view. In such a case, the form of the filter element4may be changed corresponding to the forms of the upstream case11and the downstream case12.

In this embodiment, the second curved baffle body512passes through the substantial center X of the filter element4as viewed in the direction perpendicular to the extending surface P4. The second curved baffle body512does not necessarily need to pass through the substantial center X of the filter element4. Any one of the baffle bodies50may pass through the substantial center X of the filter element4.

In this embodiment, the second end50B of the first curved baffle body511is positioned at or near the exhaust port32as viewed in the direction perpendicular to the extending surface P4. The second end50B of any baffle body50is positioned at or near the exhaust port32. The baffle body50of which the second end50B is positioned at or near the exhaust port32is not limited to the first curved baffle body511.

In this embodiment, an example having three curved baffle bodies51is shown. The number of curved baffle bodies51is at least one and may be one, two, or four or more. For example, the number of curved baffle bodies51may be two to five or three to four. In a case where the number of curved baffle bodies51is one, the curved baffle body51may be across the straight line n1. Moreover, the linear baffle body52is not necessarily needed. Alternatively, the number of linear baffle bodies52is not limited to one and may be two or more. The number of curved baffle bodies51and that of linear baffle bodies52may be changed, for example, according to at least one selected from the group consisting of the size of the air cleaner100, the position of the intake port22, and the position of the exhaust port32.

In this embodiment, the baffle body50has a constant height. The baffle body50may or may not have a constant height. For example, the baffle body50may have a larger height at greater distances from the intake port22. The baffle body50may have a regular or irregular height so as to be in a regular or irregular wave form in a side view.

In this embodiment, the first ends50A of the baffle bodies50are positioned at substantially regular intervals in the width direction. The first ends50A of the baffle bodies50may or may not be positioned at substantially regular intervals. For example, the baffle bodies50may be arranged so that the interval between adjacent two baffle bodies is larger at greater distances from the straight line n1.

In this embodiment, described is a configuration in which the guide surface501is substantially parallel with the projecting direction D1. As shown inFIG. 6, the guide surface501may be inclined with respect to the projecting direction D1in a range that does not prevent the diffusion of the air.FIG. 6is a view showing a first modification of the baffle body50according to the first embodiment. For example, an angle of inclination θ of the guide surface501with respect to the projecting direction D1may be 20° or less (1° to 20°), particularly 10° or less.

In this embodiment, the baffle body50is a solid member. The baffle body50is not limited to a solid member and may have any configuration that can diffuse an air flow (or air).FIG. 7is a view showing a second modification of the baffle body50according to the first embodiment. As shown inFIG. 7, the baffle body50may be in a hollow bead form. Specifically, the baffle body50may have a hollow form projecting toward the side in which the upstream case11is opened (or upward). The baffle body50may have a solid portion and a hollow portion. In such a case, for example, the baffle body50may be in a solid rib form on the first end50A and in a hollow bead form on the second end50B. Alternatively, the baffle body50may be in a hollow form on the first end50A and in a solid form on the second end50B.

In this embodiment, the baffle body50(the curved baffle body51and the linear baffle body52) is disposed continuously to the first side wall112along the extending surface P4. It is not necessary that the baffle part5continuously extend. The baffle part5may be formed discontinuously along the extending surface P4. In such a configuration, the baffle body50has a plurality of baffle pieces disposed regularly or irregularly along the extending surface P4. The baffle pieces may be uniform or non-uniform in size. Moreover, the interval between adjacent baffle pieces may or may not be constant.

In this embodiment, the straight line n1connecting the intake port22and the exhaust port32is offset from the center X of the filter element4. The straight line n1may pass through the center X of the filter element4. In such a case, the curved baffle body51may be disposed line-symmetrically with respect to the straight line n1.

In this embodiment, described is a configuration in which the exhaust port32is disposed at the second rear wall122b, and the second rear wall122bis parallel with the front wall112fprovided with the intake port22. The wall at which the exhaust port32is disposed is not limited to the second rear wall122b. For example, the exhaust port32may be disposed at a wall having a surface intersecting with the front wall112f, for example, a right-side wall or a left-side wall.

Second Embodiment

With reference toFIG. 8, an air cleaner100according to a second embodiment will be described. The second embodiment is different from the first embodiment in the position of the exhaust port32. Hereinafter, the differences from the first embodiment will be described, and repeated description of the first embodiment will be omitted.

FIG. 8is a plan view showing an upstream case11according to the second embodiment. InFIG. 8, a narrow long dashed double-short dashed line shows an exhaust pipe31and an exhaust port32, and a wide long dashed double-short dashed line shows a filter element4.

As shown inFIG. 8, the exhaust port32is disposed at a position different from a position facing the intake port22in the front-rear direction in a plan view. That is, the exhaust port32is not disposed substantially on a hypothetical straight line extending from the central axis m1of the intake pipe21but is disposed at a position deviating from the hypothetical straight line extending from the central axis m1. Specifically, the exhaust port32is disposed at a left-hand second side wall122of the downstream case12. Thus, a hypothetical straight line n2connecting the intake port22and the exhaust port32is not coaxial with the central axis m1of the intake pipe21and intersects with the central axis m1. Moreover, in this embodiment, the central axis m1of the intake pipe21is perpendicular to the central axis m2of the exhaust pipe31. In this embodiment, the first offset direction intersects with the second offset direction.

The exhaust pipe31projects from the exhaust port32to the left. The exhaust pipe31extends in substantially parallel with the extending surface P4or in the substantially horizontal direction. The central axis m2of the exhaust pipe31is substantially parallel with the extending surface P4. As with the first embodiment, the intake pipe21extends in substantially parallel with the extending surface P4or in the substantially horizontal direction. The central axis m1of the intake pipe21is substantially parallel with the extending surface P4.

The second embodiment has been described above. According to the second embodiment, the air introduced into the first space11S from the intake port22is diffused by the baffle bodies50and introduced to the filter element4. Thus, this prevents localized collection of dust in the filter element4. That is, the filter element4is used uniformly. This allows the filter element4to collect dust in a homogeneous distribution of dust.

The central axis m1of the intake pipe21and the central axis m2of the exhaust pipe31each extend in substantially parallel with the extending surface P4. The central axis m1of the intake pipe21and/or the central axis m2of the exhaust pipe31may be inclined upward or downward with respect to the extending surface P4. Moreover, the central axis m1and/or the central axis m2may be inclined with respect to the first side wall112and/or the second side wall122of the case1in the width direction.

Exemplary embodiments of this disclosure have been described above. However, this disclosure is not limited to the above-described embodiments, and can be implemented in various embodiments without departing from the scope thereof. The forms, shapes, and others shown in the above-described embodiments are only exemplary and not restrictive, and various modifications can be made without substantially departing from the effects of this disclosure.

For example, in the above embodiments of this disclosure, a configuration in which the air cleaner100includes two cases1independently formed (the upstream case11and the downstream case12) and the filter element4supported between the two cases1is described as an example. The air cleaner100is not limited to this configuration and may have any configuration in which the filter element4can partition the internal space1S into the first space11S and the second space12S. For example, the air cleaner100may include the filter element4put into a slit that is provided in a single or integrated case1and that extends in a width direction of the case1.

In the above embodiments of this disclosure, a configuration in which the baffle body50is integrally formed or molded with the upstream case11is described. The baffle body50may be provided separately from the upstream case11. Specifically, the baffle body50may be produced separately from the upstream case11and attached to the upstream case11. The baffle body50may be attached by, for example, welding or bonding such as vibration welding.

The air cleaner100may include other members such as a resonance silencer (a resonator or a side branch). The resonance silencer may be provided integrally with the air cleaner. Alternatively, the inside of the upstream case11or the downstream case12may be partitioned so that part of the inside can serve as the resonance silencer. In this case, the baffle body50according to the above embodiments of this disclosure may serve as part of a partition.

The air cleaner100according to this disclosure is applied to an internal combustion engine for motor cars. The air cleaner100is also successfully applied to not only the internal combustion engine for motor cars but also various applications, for example, internal combustion engines for motorcycles, housing equipment, power generation equipment, and various industrial equipment.

According to this disclosure, the air diffused by the baffle part is uniformly introduced to the filter element and is filtered through the filter element. This allows the filter element to collect dust in a homogeneous distribution of dust.

The air cleaner according to this disclosure is applicable to internal combustion engines for motor vehicles such as motor cars and motorcycles, air conditioners, fuel cells, and air cooling systems for cells and electronic circuits.

This disclosure provides illustrative, non-limiting aspects as follows.

In a first aspect, there is provided an air cleaner including a case having an internal space, a filter element capable of partitioning the internal space into a first space and a second space, an intake port that introduces an air into the first space therethrough, an exhaust port that discharges an air from the second space, and at least one baffle part that projects toward the filter element from an inner surface of the case and diffuses the air introduced into the first space and introduces the air to the filter element. The baffle part includes a first baffle part extending along an extending surface of the filter element, and the first baffle part is curved so as to be away from a hypothetical straight line connecting the intake port and the exhaust port as the first baffle part extends from the intake port toward the exhaust port as viewed in a direction perpendicular to the extending surface.

In a second aspect, there is provided the air cleaner according to the first aspect, wherein the at least one baffle part passes through a center of the filter element as viewed in the direction perpendicular to the extending surface.

In a third aspect, there is provided the air cleaner according to the first or the second aspect, wherein the first baffle part has a plurality of baffle bodies projecting from the inner surface of the case, and the baffle bodies are arranged so that a distance between adjacent two baffle bodies is larger toward the exhaust port from the intake port as viewed in the direction perpendicular to the extending surface.

In a fourth aspect, there is provided the air cleaner according to any one of the first to the third aspects, wherein the first baffle part has a plurality of baffle bodies projecting from the inner surface of the case, and as viewed in the direction perpendicular to the extending surface, a baffle body farthest of the baffle bodies away from the straight line has a curvature larger than a baffle body nearest the straight line does.

In a fifth aspect, there is provided the air cleaner according to any one of the first to the fourth aspects, wherein the first baffle part has a plurality of baffle bodies projecting from the inner surface of the case, and as viewed in the direction perpendicular to the extending surface, a baffle body farther of the baffle bodies away from the straight line has a larger curvature.

In a sixth aspect, there is provided the air cleaner according to any one of the first to the fifth aspects, wherein the first baffle part has a first end close to the intake part and a second end opposite to the first end, and the first baffle part has a curvature increased monotonically toward the second end from the first end.

In a seventh aspect, there is provided the air cleaner according to any one of the first to the sixth aspects, wherein the baffle part further includes a second baffle part, and the second baffle part is disposed linearly in a direction intersecting with an opening surface of the intake port as viewed in the direction perpendicular to the extending surface.

In an eighth aspect, there is provided the air cleaner according to any one of the first to the seventh aspects, wherein the straight line connecting the intake port and the exhaust port is offset from a center of the filter element as viewed in the direction perpendicular to the extending surface.