Title of Invention

"AIR CLEANER"

Abstract

An air cleaner comprising: an air cleaner box (10); an air cleaner element which is placed in the air cleaner box (10), and which is constituted by a first (30) and a second elements (31); and an air cleaner cover (11) that cover that covers an opening portion of the air cleaner box (10), characterized in that the first element (30) is placed at the dirty side of the second element (31), and the first and the second elements are placed so that intake air that has passed through the first element can pass through the second element, and the first element is made to be held by the air cleaner cover (11) so that a part of the intake air can pass through the second element without having passed through the first element.

Full Text

The present inventipn relates to an air cleaner. The present invention relates to an air cleaner used for an internal combustion engine of, for example, a motorcycle. In' particular, it relates to an air cleaner having an element with improved durability. [Background Art] [0002] In a conventional air cleaner, a conical first element and a cylindrical second element constitute the air cleaner element. The space inside the cylindrical portion of the second element is made to be a clean side and a housing for the first element. Outside air is taken into the conical center portion of the first element placed in the housing, and then is subjected to a dust collecting process, that is, a primary cleaning process. Furthermore, the whole part of the air that has passed through the primary cleaning process (hereinafter, referred to as "post-primary cleaning air") is made to be reflected back to the direction from which the air has flowed in. The air thus reflected is then made to swirl the area surrounding the cylindrical portion of the second element. There, the air is subjected to a secondary cleaning process by passing through the cylindrical portion from outside to inside, and the dust in the air is collected. [Patent Document 1] Japanese Utility Model Application Laid-open Official Gazette No. Hei 2 (1990)-3055. [Disclosure of the Invention] [Problems to be Solved by the Invention] [0003] The first element of the conventional air cleaner mentioned above has a structure in which outside air is taken into the conical center and thus the whole part of the intake air is subjected to the primary cleaning process using almost all the surface of the first element. This leads to a rapid degradation of the first element, and accordingly becomes a challenge when an improvement of the durability of the air cleaner as a whole is pursued. In addition, prior to the secondary cleaning process by the second element, the whole part of the intake air is, firstly, received by the first element, and is reflected back to the direction from which the air has flowed in, and then is made to swirl the area surrounding the cylindrical portion of the second element. In this way, the flowing direction of the intake air has to change a great deal, causing an increase in the air-flow resistance, while a lower air-flow resistance is desirable. Solving these problems is an object, of the invention of the present application. [Means for Solving the Problems] [0004] The invention of the present application, to solve these problems mentioned above, according to claim 1 is an air cleaner that has the following characteristics. The air cleaner has an air cleaner box, an air cleaner element placed in the air cleaner box, and an air cleaner cover covering an opening of the air cleaner: box. In addition, the air leaner element is constituted by a first and a second element. The first element is placed at the dirty side of the second element. The first and the second elements are placed in a way allowing the intake air to pass through the first element before passing through the second element. The first element is held by the air cleaner cover in a way allowing part of the intake air to pass through the second element without passing through the first element. [0005] The invention of claim 2 has the following characteristics in addition to those of claim 1. An element supporting portion that supports the first element is formed as extending from the air cleaner cover to the inside of the second element. The element supporting portion has a structure that allows part of the intake air to pass therethrough. [0006] The invention of claim 3 has the following characteristics in addition to those of claim 1. The first element is placed as facing the intake port of the intake air. [0007] The invention of claim 4 has the following characteristics in addition to those of claim 1. The second element is in a cylindrical shape, and the first element is housed inside the cylindrical portion. [0008] The invention of claim 5 has the following characteristics in addition to those of claim 1. The first element has a coarser mesh than that of the second element. [Effects of the Invention] [0009] According to the first invention, the intake air, firstly, passes through the first element while the dust in the air is collected by the first element. The resultant air, the post-primary cleaning air, flows into the dirty side of the second element. Subsequently, the post-primary cleaning air passes through the second element surrounding the post-primary cleaning air from inside to outside while the dust in the air is collected by the second element. The resultant air becomes the post-secondary cleaning air. Here, the first element is housed inside the second element with a space in between. Thus, the intake air is only partially filtered, that is, not whole part of the intake air is filtered by the first element. As a result, clogging of the first element can be curbed and, at the same time, clogging of the second element can also be curbed. Thus, the air cleaner element as a whole has a longer service life and its durability is improved. [0010] In addition, the intake air, having passed through the first element, flows into the dirty side of the second element, and the air passes through the second element from inside to outside. As a result, the air-flow resistance can be lessened down to a minimum level. Moreover, the first element is held by the air cleaner cover, so that, just to remove the air cleaner cover, the first element is ready for the maintenance. As a result, the maintenance of the air cleaner can be made easier. [0011] According to the second invention, the first element is supported by the element supporting portion, while the element supporting portion extends from the air cleaner cover and has a structure that is permeable to air. With this first element, only part of the intake air is filtered and is allowed to pass through to the second element side as the post-primary cleaning air . At the same time, the first element can be firmly supported by the element supporting portion with the air-permeable structure. .[0012] According to the third invention, since the first element is placed as facing the intake port of the intake air, most of the intake air flowing in from the intake port can be filtered with the first element, As a result, the dust in the intake air can be collected efficiently. Relatively large particles of dust are hit against: the first element, so that the first element can collect these large particles without fail. [0013] According to the fourth invention, the second element is formed in a cylindrical shape. The space inside the cylindrical portion is made to be the dirty side, and can be used for the housing for the first element. As a result, the space where the first element may otherwise be placed can be saved. [0014] According to the fifth invention, the first element is made to be coarser than the second element. Dust with larger particles can be collected with the first element, and dust with finer particles is collected by the second element. As a result, each of the two elements can have a longer filter-exchange cycle than otherwise. In addition, the longer exchange cycle can be accomplished while the intake resistance is prevented from increasing. Moreover, employing the coarse first element can further reduce the air-flow resistance. [Best Mode for Carrying Out the Invention] [0015] Explanations of an embodiment will be given below by referring to the drawings. [Brief Description of the Drawings] [0043] [Fig. 1] Fig. 1 is a side view of a motorcycle equipped with an air cleaner. [Fig. 2] Fig. 2 is a side view of the air cleaner. [Fig. 3] Fig. 3 is a top plan view with a part being cut away. [Fig. 4] Fig. 4 is a perspective view of a cover. [Fig. 5] Fig. 5 is a front elevational view of the cover. [Fig. 6] Fig. 6 is a top plan view of the cover. [Fig. 7] Fig. 7 is a side view of the cover. [Fig. 8] Fig. 8 is a sectional view taken along the line 8-8 in Fig. 5. [Fig. 9] Fig. 9 is a view corresponding to Fig. 4 in another embodiment. •-.-IT.2=-.. Fig. 1 shows the right side of a motorcycle equipped with an air cleaner of the invention of the present application. [0016] An engine 3 is located between a front wheel 1 and a rear wheel 2, and is supported by a body frame 4. Cleaned air is supplied from an air cleaner 5 placed at the rear portion of the body, through a connecting tube 6, to an intake port of the engine 3. [0017] An exhaust pipe 7 extends from an exhaust port of the engine 3. The exhaust pipe 7 extends rearward passing under the engine 3, and is connected to a muffler 8 placed on a side of the rear wheel 2. Reference numerals 10, 11 and 12 are, respectively, an air cleaner box of the air cleaner 5, an air cleaner cover and an inlet duct. The inlet duct 12 has an opening placed at the rear of the air cleaner box 10 and facing inner side of the body, and outside air is taken into the air cleaner 5 from the rear portion of the body. [0018] A fuel tank 13 is placed over the engine 3. A sheet 14 is placed at the rear of the fuel tank 13 and over the air cleaner 5. Reference numerals 15, 16, 17, 18 and 19 are, respectively, a head pipe, a front fork, a bottom bridge, a top bridge, and a handle. [0019] Fig. 2 is a left side view of the air cleaner 5. The connecting tube 6 extends forward from a front wall 20 of the air cleaner box 10. An opening portion 12a of the inlet duct 12 laps on a back wall 21 of the air cleaner box 10 from the rear side. Precisely, a side portion of the opening portion 12a of the inlet duct 12 laps on an upper portion of the back wall 21. [0020] Attachment bosses 23 and 24 are formed on a top wall 22 of the air cleaner box 10. The bosses 23 and 24 protrude upward from the wall 22. Other attachment bosses 24 are integrally formed in the lower portion of the back wall 21, and on the upper and the lower portions of the front wall 20. A drain tube 27 extends downward from a bottom wall 26 of the air cleaner box 10. A tool box 28 is attached to an under face of the bottom wall 26 and in front of the drain tube 27. [0021] Fig. 3 is a top plan view of the air cleaner 5 with a part thereof being cut away. The air cleaner box 10 has an opening towards the right of the body. The opening is closed by the air cleaner cover 11, which is attached thereto. The forward end portion of the inlet duct 12 is connected to a side surface of the air cleaner cover 11. The inlet duct 12, firstly, extends rearward, and then bends approximately at a right angle toward the inner side of the body. The inlet duct 12 passes over the junction between the air cleaner box 10 and the air cleaner cover 11, and then lies on the back wall 21. The opening 12a is positioned at a place near the junction between the air cleaner box 10 and the air cleaner cover 11. [0022] An air cleaner element is housed in the air cleaner box 10. A first element 30 and a second element 31, both of which are to be described later, constitute the air cleaner element. Some appropriate material, such as a sponge material, which has a filter effect, is used for the first element 30. In this embodiment, a sponge plate with a certain predetermined thickness is used for the purpose. The first element 30 extends from the air cleaner cover 11 toward the inner side of the air cleaner box 10, to form a tongue shape. An element supporting portion 35, which supports the first element 30, has a shape that does not disturb the flow of the air from the opening 12a of the inlet duct 12 at the place where the element supporting portion 35 is fixed to the air cleaner cover 11. [0023] The second element 31 is made of a known material such as a sponge material, and surrounds the first element 30. Paper and nonwoven fabric materials may be used as the filtering material. Note that, the first element 30 is used for the primary cleaning process, and, accordingly, is coarser than the second element 31. Specifically, the second element 31 is made fine enough to produce intake air for engine by collecting finer particles of dust, while the mesh of the first element 30 is set to have any fineness that is coarser than that of the second element 31. Note, however, that the same material as that used for the second element 31 may be used for the first element 30. [0024] The space inside the cylindrical second element 31 is a dirty side 25a, and the space outside is a clean side 25b. The first element 30 is housed in the dirty side 25a, and there is a space between the first element 30 and the inner circumferential surface of the second element 31. As is shown by arrows in the figure, outside air is taken into the dirty side 25a from the inner side of the body through the inlet duct 12. Part of the air thus taken in flows through the first element 30 and then the second element 31, and is subjected to both cleaning processes. Some other part of the air flows as being in contact with the first element 30, while still other part of the air flows as not being in contact with the first element 30. Both of the two parts above, then, pass through the second element 31, and are subjected to a cleaning process. [0025] Fig. 4 is a perspective view of the air cleaner cover 11. The air cleaner cover 11 has a substantially cap-shaped main body 32 with an opening toward air cleaner box 10. The inlet duct 12 and the first element 30 are attached to the air cleaner cover 11. The main body 32 is made of an appropriate, relatively stiff plastic, such as polypropylene. The junction with the air cleaner box 10 is formed into a ring-shaped fit flange 33. Mounting bosses 33a are integrally formed by protruding from the fit flange 33 with appropriate intervals in a circumferential direction. [0026] The first element 30 laps on and is supported by the element supporting portion 35. The element supporting portion 35 has a half-round shape, precisely, a shape of a halved cylinder cut along the length directions. The first element 30 is fixed to the surface of the element supporting portion 35 with claws 36. The front end in a length direction is made to be a stopper 35b, which defines the position of the front end of the first element 30. The other end of the element supporting portion 35 in the length direction is a mounting portion 35a, with which the element supporting portion 35 is mounted to the inside of the main body 32. Conseguently, the element supporting portion 35 has the first end side extending far out from the main body 32 in a long tongue shape, while the other end of the element supporting position 35 is cantilevered by the main body 32. [0027] Fig. 5 is a view showing the air cleaner cover 11 viewed from the direction indicated by arrow A in Fig. 4. While the fit flange 33 has a circular shape, each of the element supporting portion 35 and the first element 30, which laps on the element supporting portion 35, is curved as being convex downward to have an approximately a third arc shape at the narrower side. With the concave curve surface facing upward, each of the element supporting portion 35 and the first element 30 is placed, in an approximately coaxial way, inside the fit flange 33. The arc at outer circumference side of the element supporting portion 35c is an arc of a smaller radius than that of the fit flange 33. A relatively large space represented by D is kept evenly between the outer circumferential surface of the element supporting portion 35 and the inner circumference of the fit flange 33. Similarly, a space d is kept evenly between the outer circumferential surface of the element supporting portion 35 and the inner circumference of the second element 31. [0028] The first element 30 forms a downwardly concave curve surface as surrounding the center O of the fit flange 33 from below. The first element 30 receives some part of the outside air which is taken in from an intake port (described later) formed on the main body 32 and positioned over and at the right of the first element 30, and which comes to the first element 30 obliquely downward as is indicated by arrow a. The first element 30, however, is shaped in an arc and is placed inside the second element 31 with a space d being kept in between. Thus, as is shown by arrow b, some other part of the intake air flows directly to the second element 31 without passing through the first element 30. The angle of aperture of the first element 30 around the center 0 is approximately 120° in a case of this embodiment. By changing this angle, the proportion of the intake air subjected to the filtration by the first element 30 is freely adjusted. [0029] Fig. 6 is a view from the direction indicated by arrow B in Fig. 4. Fig. 7 is a view from the direction indicated by arrow C in Fig. 4. An intake port 34 is formed on a side face 32b of the main body 32 of the air cleaner cover 11. An end of the inlet duct 12 is hermetically connected to the intake port 34. The intake port 34 is formed on the side face 32b in a part equivalent to approximately a quadrant in a circumferential direction. The intake port 34 overlaps a part of the first element 30 that is placed inside the main body 32 in Fig. 6. This figure clearly shows that the intake port 34 opens towards a portion of the surface of the first element 30. By adjusting the size of the intake port 34, the amount of intake air can be adjusted. On the other hand, the position where the intake port 34 is formed can be used to adjust the amount of air assigned to the filtration by the first element 30. [0030] The first element 30 laps on the upper surface of the element supporting portion 35 entirely in the length directions. The mounting portion 35a of the element supporting portion 35 laps on the bottom portion 32a of the main body 32, and is fixed thereto with screws 39a (see Fig. 7) and nuts 39b (see Fig. 5) . The element supporting portion 35 has a structure that is permeable to air. In this embodiment, as is shown in Fig. 6, multiple ribs 37 of a resin material are formed in a lattice shape, and the air-permeable structure is accomplished by multiple spaces 38 formed between the ribs 37. [0031] Fig. 8 shows a section taken along the line 8-8 in Fig. 5. The mounting portion 35a of the element supporting portion 35 forms a curved surface along the bottom portion 32a of the main body 32 and laps thereon relatively widely. The portion of the first element 30 that is inside the main body 32 faces the intake port 34. Part of the air taken in from the intake port 34 passes through the first element 30, then through the space 38, and then permeates to the outside of the first element 30 to flow into the dirty side 25a. Some other part of the intake air flows as not being in contact with the first element 30. [0032] Subsequently, explanations will be given as to the advantageous effects of this embodiment. Firstly, the air cleaner cover 11 is attached to the air cleaner box 10. Outside air is taken in from the inlet duct 12 while the first element 30 is housed inside the second element 31. The first element 30 is substantially in a semi-cylindrical shape, and the upper surface of the first element 30 opens towards the intake port 34. As a result, part of the intake air flows in a direction indicated by an arrow a, as is shown in Fig. 8. Then, the part of the air passes through the first element 30, and is subjected to the primary cleaning process. Relatively large dust, such as sand, is removed from the outside air in which the dust is mixed, with use of the first element 30. [0033] Most of the intake air flows in a direction indicated by an arrow b, along the first element 30, or alternatively, permeates the first element 30. The dust in the air is collected when the air is brought into contact with the first element 30. Additionally, in a case where the air flow greatly changes the direction by the first element 30, the inertia and the centrifugal force bring larger particles of dust into contact with the first element 30, and thus the dust is collected. Moreover, some other part of the intake air that is not brought into contact with the first element 30 flows directly into the second element 31, and passes therethrough. [0034] The first element 30 is housed in the dirty side 25a of the second element 31. Thus, the air having passed through the first element 30 flows in the dirty side 25a. The air, which has never been brought into contact with the first element 30, also flows in the dirty side 25a. Then, the air flowing in the dirty side 25a passes through the second element 31 from the dirty side 25a, that is, the inner side of the second element 31 to the clean side 25b, that is, its outer side. Here, the air is subjected to the secondary cleaning process. In other words, fine dust in the air is further collected. The resultant air is supplied to the engine 3 through the connecting tube 6 (see Fig. 3) . [0035] In this way, only part of the intake air passes through the first element 30, then flows into the dirty side 25a of the second element 31, and then passes through the second element 31 from its inside to its outside. Thus, the first element 30 filters not the whole of the intake air, but only part thereof. As a result, an increase in the intake resistance is curbed, which may otherwise be brought about by the clogging of the first element 30. In addition, the air cleaner element as a whole has a longer filter-exchange cycle than otherwise, so that the durability of the air cleaner element is improved. [0036] In addition, the post-primary cleaning air, which has passed through the first element 30, goes straight to the second element 31, which is placed outside of the first element 30. Some other part of the intake air flows in the dirty side 25a, and goes directly to the second element 31 without being brought into contact with the first element 30. As a result, the air-flow resistance for the intake air can be lessened down to a minimum level. [0037] Moreover, the first element 30 is made to be held, with the element supporting portion 35, by the main body 32 of the air cleaner cover 11. With this configuration, just to remove the air cleaner cover 11, the first element 30 is ready for the maintenance. As a result, the maintenance of the air cleaner becomes easier. In addition, the first element 30 is firmly supported by the element supporting portion 35, which has a air-permeable structure, and which extends towards the inside of the dirty side 25a as being in a cantilever shape. [0038] Furthermore, the element supporting portion 35 is formed as a separate body from the air cleaner cover 11, and is made to be freely attached to or detached from the bottom portion 32a of the main body 32 with use of, for example, screws. As a result, the air cleaner cover 11 is made separable into the main body 32 and the first element 30 sides. When the maintenance of the first element 30 and the element supporting portion 35 is carried out, the part that requires, for example, an exchange is smaller than otherwise. Thus, the air cleaner cover is made to be economical. [0039] Still furthermore, the first element 30 is placed as facing the intake port 34, which is the port from which the intake air is taken in. Most of the intake air flowing in from the intake port 34 is filtered with the first element 30. As a result, the dust in the intake air is collected efficiently. Additionally, the first element 30 is coarser than the second element 31. Thus, with the first element 30, firstly, only the larger dust in the intake air is collected, and then with the second element 31, the finer dust in the intake air is collected. As a result, each of the elements 30 and 31 has a longer service life than otherwise. At the same time, the use of the coarse first element 30 further reduces the air-flow resistance. [0040] Finally, the second element 31 has a cylindrical shape, and the inside of the cylindrical portion is made to be the dirty side 25a and to be the housing for the first element 30, which has a substantially semi-cylindrical shape. As a result, a relatively longer first element 30 is housed in the second element 31, and the space where the first element 30 may otherwise be placed can be saved. [0041] Note that, the invention of the present application is not limited to the embodiment that has been described thus far. Various modifications and applications can be made within the principle of the inve-ntion. For example, materials and structures for the first element 30 and for the element supporting portion 35 can be changed in various ways. Fig. 9. is a perspective view corresponding to Fig. 4 in another embodiment as mentioned above. In this embodiment, a metal sheet is, for example, pressed to be formed into the element supporting portion 35. The surface where the first element 30 is supported is made, for example, of a perforated metal with a web structure or a perforated structure. A wire-mesh first metal element 30 is also allowable. The first element 30 formed in these ways is inexpensive. Note that, when the main body 32 is made of a resin, the element supporting portion 35 may be integrally formed with the main body 32. [0042] In addition, for the first element 30, any appropriate material, as long as the material has a filtering effect, can be used. For example, a fiber material, such as paper, cloth/ and nonwoven cloth, or a sponge material can be used by forming such a material into a plate or a block shape. At this time, a liquid for collected dust may be impregnated, or the surface may be made adhesive, when needed. Thus, relatively large dust is collected efficiently. Moreover, the first element may be formed in a pouch-like shape. Thus, just to put the pouch-like first element over the element supporting portion 35, the first element 30 is attached to the element supporting portion 35. This makes the attaching or detaching operation to be easier and quicker than otherwise. [Explanation of the Reference Numerals] [0044] 5: AIR CLEANER, 6: CONNECTING TUBE, 10: AIR CLEANER BOX, 11: AIR CLEANER COVER, 12: INLET DUCT, 30: FIRST ELEMENT, 31: SECOND ELEMENT, 32: MAIN BODY, 35 ELEMENT SUPPORTING PORTION. We claim: 1. An air cleaner comprising: an air cleaner box (10); an air cleaner element which is placed in the air cleaner box (10), and which is constituted by a first (30) and a second elements (31); and an air cleaner cover (11) that cover that covers an opening portion of the air cleaner box (10), characterized in that the first element (30) is placed at the dirty side of the second element (31), and the first and the second elements are placed so that intake air that has passed through the first element can pass through the second element, and the first element is made to be held by the air cleaner cover (11) so that a part of the intake air can pass through the second element without having passed through the first element. 2. The air cleaner as claimed in claim 1, wherein the said first element (30) is supported by an element supporting portion (35), which is formed as extending from the air cleaner cover (11) towards the inside of the second element (31), and the element supporting portion has a structure that allows part of the intake air to permeate the element supporting portion. 3. The air cleaner as claimed in claim 1, wherein the first element (30) is placed to face the intake port for the intake air. 4. The air cleaner as claimed in claim 3, wherein the second element (31) has a cylindrical shape, and the first element (30) is housed inside the cylindrical portion. 5. The air cleaner as claimed in claim 1, wherein the first element (30) is coarser than the second element (31).

Documents:

2789-DEL-2006-Abstract-(24-04-2012).pdf

2789-DEL-2006-Abstract-(26-08-2009).pdf

2789-del-2006-abstract.pdf

2789-DEL-2006-Claims-(24-04-2012).pdf

2789-DEL-2006-Claims-(26-08-2009).pdf

2789-del-2006-claims.pdf

2789-del-2006-Correspondence Others-(12-04-2012).pdf

2789-DEL-2006-Correspondence Others-(24-04-2012).pdf

2789-del-2006-Correspondence-Others-(26-02-2010).pdf

2789-DEL-2006-Correspondence-Others-(26-08-2009).pdf

2789-DEL-2006-Correspondence-Others.pdf

2789-DEL-2006-Description (Complete)-(26-08-2009).pdf

2789-del-2006-description (complete).pdf

2789-DEL-2006-Drawings-(26-08-2009).pdf

2789-DEL-2006-Drawings.pdf

2789-del-2006-form-1.pdf

2789-del-2006-form-18.pdf

2789-del-2006-form-2.pdf

2789-DEL-2006-Form-3-(26-08-2009).pdf

2789-del-2006-form-3.pdf

2789-del-2006-form-5.pdf

2789-del-2006-GPA-(12-04-2012).pdf

2789-DEL-2006-GPA-(26-08-2009).pdf

2789-DEL-2006-Petition-137-(26-08-2009).pdf

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