Title of Invention

AIR CLEANER FOR MOTORCYCLE

Abstract

1. An air cleaner for a motorcycle wherein: an air cleaner case is divided by a filter element into a dirty side space and a clean side space; the clean side is divided and forms a sub-chamber; and the sub-chamber communicates with an outlet of a blowby hose for recirculating a blowby gas from a crankcase of an engine, and with an inlet of a secondary air supply pipe for supplying secondary air to an exhaust system of the engine.

Full Text

FORM 2 THE PATENTS ACT 1970 [39 OF 1970] COMPLETE SPECIFICATION [See Section 10] "AIR CLEANER FOR MOTORCYCLE" HONDA GIKEN KOGYO KABUSHIKI KAISHA, a corporation of Japan, having a place of business at 1-1, Minamiaoyama 2-chome, Minato-ku, Tokyo, Japan, The following specification particularly describes the nature of the invention and the manner in which it is to be performed: - ORIGINAL 754/MUMNP/2000 GRANTED 18-7-2005 The present invention relates to an air cleaner for a motorcycle. [0001] [Technical Field] The present invention relates to an air cleaner for a motorcycle which is compact and suitable for suppression of intake noise and is manufactured at a reduced cost. [0002] [Related Art] The following air cleaners for engines are known: (1) an air cleaner which can suppress intake noise, and (2) "Air Cleaner for Internal Combustion Engine" disclosed in Japanese Utility Model Publication No. Sho. 60-32373. [0003] The air cleaner of the related art (1) will be described with reference to Fig. 7. Fig. 7 is a side view of the air cleaner 100. The air cleaner 100 is constituted by the air cleaner case 101, a connecting tube 102 extending from the air cleaner case 101 to the carburetor (not shown), and the resonator 103 attached to an outer surface of the connecting tube 102 in order to suppress noise of intake air sucked into the air cleaner case 101. The resonator 103 resonates the air in the closed space communicating with the connecting tube 102, thereby suppressing intake noise. [0004] The related art (2) discloses the air cleaner in which the air cleaner cas (Brief Description of the Drawings] Fig. 1 is a side view of the motorcycle provided with the air cleaner of the present invention. Fig. 2 shows routes connecting the air cleaner and the engine. Fig. 3 is a side view of the air cleaner. Fig. 4 is a sectional view of the air cleaner taken along line 4-4 in Fig. 3. Fig. 5 is a sectional view of the air cleaner taken along line 5-5 in Fig. 3. Fig. 6 shows the operation of the sub-chamber. Fig. 7 is a sectional view of an air cleaner of the related art. [0016] ' [Description of the Preferred Embodiment] The invention will be described hereinafter with reference to the preferred embodiment shown on the accompanying drawings, which should be viewed in the orientation of the s. Fig. 1 is a side view of a motorcycle 10 provided with an air cleaner according . to the invention. The motorcycle 10. comprises: a head pipe 11; a front fork 12 coupled to the head pipe 11 so as to be freely steered; a front wheel 13 attached to the bottom of the front fork 12; a handlebar I4 attached to be integral with the top of the front fork 12; a body frame 15 extending behind the head pipe 11; a power unit 18 attached at the lower part of the body frame I5 and including an engine 16 and a transmission system 17; a rear wheel 21 driven by the power unit 18 via a chain (not shown); a rear cushion unit 22 extending between the rear part of the body frame 15 and the rear wheel 21; a fuel tank 23 at the upper part of the body frame 15; a seat 24 positioned behind the fuel tank 23; and an air cleaner 25 positioned under the front part of the seat 24 and at one side of the body frame 15. [0017] The motorcycle 10 further includes: a headlamp 27; a carburetor 28; a connecting tube 29 for connecting the air cleaner 25 and the carburetor 28; an intake pipe 31 for connecting the carburetor 28 and the engine 16; a secondary air supply pipe 32 for supplying the secondary air to an exhaust system of the engine 1.6; a flow control valve 33 arranged halfway along the secondary air supply pipe 32; a blowby hose 34 for recirculating a blowby gas from a crankcase 35 of the engine 16; a side cover 36 extending over a side of the air cleaner 25; a side stand 37; and a tail-light 38. [0018] Fig. 2 shows routes via which the air cleaner 25 is connected to the engine 16. The air cleaner 25 includes an air cleaner case 42 which is divided by a filter element 43 into an element front chamber 44 as a dirty side space, and an element rear chamber 45 as a clean side space. The element rear chamber 45 is partly divided by a partition 46 in order to form an element inner chamber 47 in the filter element 43, and a sub-chamber 48. The element inner chamber 47 and the sub-chamber 48 communicate with each othervia an opening 43a. The sub-chamber 48 is divided into a first sub-chamber 48a and a second sub-chamber 48b using a labyrinth 52 which is constituted by first and second projecting walls 49 and 51. Therefore, the first and second sub-chambers 48a and 48b communicate with each other via the labyrinth 52. [00.19] The dirty side space (i-.e. the element front chamber 44) receives outside air containing contaminants such as dust while the clean side space (i.e. the element rear chamber 45) is filled with clean air which passes through the filter element 43 and is free from the contaminants. [0020] In Fig. 2, 53 denotes an inlet of the air cleaner case 42; 54 denotes an inlet of the secondary air supply pipe 32; 55 denotes an outlet of the blowby hose 34; 56 denotes an exhaust pipe connected to the engine 16; 57 denotes a muffler attached to an end of the exhaust pipe 56; 58 denotes a tail pipe connected to the rear end of the muffler 57; 61 denotes a discharge port of the secondary air supply pipe 32 connected to the exhaust pipe 56; and 62 denotes an inlet of the blowby hose 34 connected to the crankcase 35 of the engine 16. [0021] Fig. 3 is a side view of the air cleaner with a rid of the air cleaner case removed. The air cleaner 25 has the inlet 53 connected to the rear part of the air cleaner case 42, the filter element 43 housed in the air cleaner case 42, and the sub-chamber 48 positioned at the front part of the air cleaner case 42 and having an oval shape when viewed from a side. In Fig. 3, 64 denotes a chamber lid extending over the side of the sub-chamber 48, and 65 denotes a small screw for attaching the chamber cover 64 to the air cleaner case 42. [0022] Fig. 4 is a sectional view of the air cleaner 25 taken along line 4-4 in Fig. 3, showing that the air cleaner 25 is provided with: the air cleaner case 42, filter element 43; the sub-chamber 48 which is formed by dividing the element rear chamber 45 using the partition 64; the chamber lid 64 extending over the side of the sub-chamber 48, and a lid 66 covering the side of the air cleaner case 42. [0023] The filter element 43 is a cylindrical element having a bottom, has its open end attached to the partition 47 of the sub-chamber 48, and communicates with the sub- chamber 48. The sub-chamber 48 communicates with the connecting tube 29 attached to the front part of the chamber case 46. [0024] As described so far, the air cleaner 25 has the air cleaner case 42 divided by the filter element 43 into the dirty side space and the clean side space. The clean side space of the air cleaner case 42 is divided in order to form the sub-chamber 48 which functions as the resonator for attenuating intake sound. Therefore, the air cleaner case 42 including the sub-chamber 48 can be made compact, which enables the air cleaner 25 to be installed in the motorcycle 10 (see Fig. 1) without any problem. [0025] In the related art, the resonator is separate from the connecting tube extending between the carburetor and the air cleaner case. However, the air cleaner case 42 made of resin can be easily formed using a single die, which is effective in reducing the manufacturing cost. Therefore, the air cleaner 25 can be made compact, suppress intake sound and be manufactured at a reduced cost. [0026] In the air cleaner 25, the filter element 43 is cylindrical and has its bottom projecting to the dirty side space, i.e. element front chamber 44. Therefore, when an existing cylindrical element having a bottom is used and the partition 47 is shaped similarly to the existing partition in order to receive the filter element 43, it is not necessary to use a filter element of a new design. This is effective in suppressing an increase in the manufacturing cost. [0027] Fig. 5 is a sectional view of the air cleaner case 42 taken along line 5-5 in Fig. 3. The air cleaner case 42 is provided with the first projecting wall 49 at the lower part of the sub-chamber 48, the intake pipe 67 positioned above the first projecting wall 49, and the discharge pipe 68 under the first projecting wall 49. The intake pipe 67 communicates with the inlet port 54 of the secondary air supply pipe 32 while the discharge pipe 68 communicates with the discharge port 55 (see Fig. 3) of the blowby hose 34 (see Fig. 3). The chamber lid 64 includes the second projecting wall 51 which extends along the first projecting wall 49 and forms the labyrinth 52 near a corner of the sub-chamber 48. [0028] The second projecting wall 51 is provided on the chamber lid 64, so that the first and second projecting walls 49 and 51 can be easily-formed. The chamber lid 64 can be easily attached to the air cleaner case 42 using the small screws 65. Further, the labyrinth 52 can be formed with ease simply by attaching the chamber lid 64 to the air cleaner case 42. [0029] The air cleaner operates in the following manner. First of all, the air, blowby gas and exhaust gas flow through the routes connecting the engine 16 and the air cleaner 25 as shown in Fig. 2. The air (shown by white arrows) flows into the element front chamber 44 of the air cleaner case 42 via the inlet port 53 of the air cleaner 25, passes through the filter element 43, has contaminants such as dust removed, and reaches the element inner chamber 47. [0030] The air in the element inner chamber 47 flows into the sub-chamber 48 via the opening 43a, advances to the carburetor 28 from the sub-chamber 48 via the connecting tube 29, passes through the intake pipe 31, and reaches a combustion chamber (not shown) of the engine 16 together with fuel. Thereafter, the air is burnt together with the fuel, and is discharged outside via the exhaust pipe 56, muffler 57, and tail pipe 58. [0031] Some of the air in the sub-chamber 48 flows into the secondary air supply pipe 32 via the inlet port 54 at the top of the second sub-chamber 48a of the sub-chamber 48, has a flow rate controlled by the flow control valve 33, and reaches the exhaust pipe 56 via the discharge port 61 of the secondary air supply pipe 32. Components such as HC and NO are oxidized by the air, and are discharged to the outside via the muffler 57 and tail pipe 58. [0032] During the operation of the engine 16, some of the burnt gases flowing into the crankcase 35 from the combustion chamber is mixed with oil mist in the crankcase 35, and results in a blowby gas. [0033] The blowby gas flows into the first sub-chamber 48 of the sub-chamber 48 via the blowby hose 34 and discharge port 55 as shown by arrows with dashed lines because of the pressure inside the crankcase 35. Thereafter, the blowby gas in the first sub-chamber 48a flows into the second sub-chamber 48b via the labyrinth 52, and further into the combustion chamber of the engine 16 via the connecting tube 29, carburetor 28 and intake pipe 31. Finally, the blowby gas is burnt in the combustion chamber and is discharged to the outside as an exhaust gas. [0034] As described above, in the air cleaner 25, the sub-chamber 48 communicates with the discharge port 55 of the blowby hose 55 and with the inlet port 54 of the secondary air supply pipe 32. The sub-chamber 48 functions not only as the resonator but also as a reserve tank for separating oil from the blowby gas and as an air chamber for supplying the secondary air. Therefore, the air cleaner 25 can be made compact compared with a case where the reserve tank and the air chamber are separate from the sub-chamber 48. [0035] The operation of the sub-chamber 48 will be described hereinafter with reference to Figs. 6(a) to 6(c). Referring to fig. 6(a), when the blowby gas flows into the first sub-chamber 48a, gases and oil mist in the blowby gas pass through the labyrinth 52, or through a gap between the first and second projecting walls 49 and 51, and reach the second sub-chamber 48b. Further, liquid oil F in the blowby gas is blocked by the labyrinth 52 and is kept at the bottom of the first sub-chamber 48a. [0036] As shown in Fig. 6(b), the liquid oil F kept in the first sub-chamber 48a flows to the discharge port 55 via the discharge pipe 68 at the bottom of the air cleaner case 42, and is returned to the crankcase 35 of the engine 16. In this state, the discharge pipe 68 has its inner bottom smoothly coupled to the bottom of the first sub-chamber 48a, and has its end sloped downward by a. As a result, the liquid oil F can be easily discharged out of the first sub-chamber 48a, so that no drain hole will be necessary in the first sub-chamber 48a. [0037] Referring to Fig. 6(c), when the engine is stopped and the side stand is used to keep the motorcycle 10 stationary, the air cleaner case 42 is inclined by an angle B, and the liquid oil F is collected at the discharge opening 68a of the discharge pipe positioned near the chamber lid 64 of the air cleaner case 42. This is because the chamber lid 64 is positioned near the side stand. Therefore, the liquid oil F can be reliably returned to the engine 16. {0038] The liquid oil F in the blowby gas blowing out of the discharge pipe 68 can neither pass through the labyrinth 52 at the corner of the sub-chamber 48 nor flow into the center of the sub-chamber 48, i.e. into the second sub-chamber 48b. Therefore, the air free from the liquid oil F can be taken in via the inlet port 54 of the secondary air supply pipe 32, which promotes purification of exhaust gases in the exhaust pipe 56. [0039] The sub-chamber 48 communicates with the discharge port 55 (shown in Fig. 2) of the blowby hose 34 (shown in Fig. 1) at the bottom thereof, and with the inlet port 54 of the secondary air supply pipe 32 at the top thereof. The blowby gas is taken in via the inlet port of the connecting tube 29 substantially at the center of the sub-chamber 48, and cannot flow into the secondary air supply pipe 32. As a result, only the air purified by the filter element 43 (shown in Fig. 4) and being free from contaminants such as dust can be introduced into the secondary air supply pipe 32. [0040] The filter element 43 is the cylindrical element with the bottom as shown in Fig. 4. Alternatively, the filter element 43 may be flat. In such a case, a space corresponding to the element inner chamber 47 is an element side chamber positioned beside the flat filter element. The element front chamber, flat filter element, element side chamber and sub-chamber 48 are arranged in this order in the air cleaner case 42. [0041] [Effects of the Invention] The air cleaner of the invention is advantageous in the following respects. According to claim 1, the air cleaner for the motorcycle includes the air cleaner case whose clean side space is partitioned in order to from the sub-chamber, which functions as the resonator. The air cleaner case having the sub-chamber can be made compact and be installed in the motorcycle without any problem. [0042] The air cleaner case made of resin can be easily shaped using a single die, and be manufactured at a reduced cost compared with the case in which the resonator as a separate unit is attached to the connecting tube extending between the air cleaner case and carburetor in the related art. Therefore, the air cleaner can be made compact, suppress intake noise and be manufactured at a reduced cost. [0043] The blowby hose is connected to the sub-chamber via its discharge port, and the inlet port of the secondary air supply pipe is connected to the sub-chamber via the inlet port thereof. The sub-chamber functions not only as the resonator but also as the reserve tank for separating oil from the blowby gas and the air chamber for supplying the secondary air. The air cleaner can be made compact compared with the case where the reserve tank and air chamber are separate from the sub-chamber. [0044] In the air cleaner, the sub-chamber is provided with the labyrinth at the corner thereof, so that liquid oil can neither pass through the labyrinth nor flow to the center of the sub-chamber, as defined in claim 2. [0045] According to claim 3, the air cleaner includes the filter element which is cylindrical and has the bottom. The bottom of the filter element projects into the dirty side, space. Therefore, when a bottomed cylindrical filter element of the related art is used and a filter element receiving part in the air cleaner case is shaped similarly to that of the related art, the air cleaner can be obtained at a reduced cost. DESCRIPTION OF REFERENCE NUMERALS 10 ... motorcycle, 16 ... engine, 25 ... aix cleaner, 32 ... secondary air supply pipe, 34 ... blowby hose, 35 ... crankcase, 42 ... air cleaner case, 43 ... filter element, 44 ... dirty side space (element front chamber), 45"... clean side space (element rear chamber), 48 ...• sub-chamber, 52 ... labyrinth, 54 ... intake port, 55 ... discharge port. WE CLAIM: 1. An air cleaner for a motorcycle wherein: an air cleaner case is divided by a filter element into a dirty side space and a clean side space; the clean side is divided and forms a sub-chamber; and the sub-chamber communicates with an outlet of a blowby hose for recirculating a blowby gas from a crankcase of an engine, and with an inlet of a secondary air supply pipe for supplying secondary air to an exhaust system of the engine. 2. The air cleaner as claimed in claim 1, wherein a labyrinth is formed at a corner of the sub-chamber, and the blowby gas is introduced to the center of the sub-chamber via the labyrinth. 3. The air cleaner as claimed in claim 2, wherein the filter element is a cylindrical element having a bottom which projects into the dirty side space. 4. An air cleaner for a motorcycle substantially as herein described with reference to figure 1 to 6 of the accompanying drawings. Dated this 14th day of August, 2000. [RITUSHKA NEGI] OF REMFRY & SA)GAR ATORNEY FOR THE APPLICANTS

Documents:

754-mum-2000-cancelled pages(18-07-2005).pdf

754-mum-2000-claims(granted)-(18-07-2005).doc

754-mum-2000-claims(granted)-(18-07-2005).pdf

754-mum-2000-correspondence(23-03-2006).pdf

754-mum-2000-correspondence(ipo)-(20-07-2004).pdf

754-mum-2000-drawing(04-10-2001).pdf

754-mum-2000-form 1(14-08-2000).pdf

754-mum-2000-form 1(21-07-2005).pdf

754-mum-2000-form 19(16-04-2004).pdf

754-mum-2000-form 2(granted)-(18-07-2005).doc

754-mum-2000-form 2(granted)-(18-07-2005).pdf

754-mum-2000-form 3(14-08-2000).pdf

754-mum-2000-form 3(15-03-2001).pdf

754-mum-2000-form 3(18-07-2005).pdf

754-mum-2000-form 5(14-08-2000).pdf

754-mum-2000-petition under rule 137 (18-07-2005).pdf

754-mum-2000-petition under rule 138(18-07-2005).pdf

754-mum-2000-power of authority (18-07-2005).pdf

754-mum-2000-power of authority (28-11-2000).pdf

abstract1.jpg