Title of Invention

"SECONDARY AIR SUPPLYING DEVICE FOR EXHAUST GAS SYSTEM OF SMALL-SIZED MOTORCYCLE"

Abstract To eliminate a fixing or a removing of a cover during maintenance work for a secondary air supplying device for an exhaust gas system of a small-sized motorcycle, reduce a restriction in design of an air cleaner, improve an effect of muffling action and further shorten a length of a secondary air supplying pipe. [Solving Means] The air cleaner 35 for the exhaust gas system is arranged at the muffler 28 in a device of which extremity end is connected to the air cleaner 35 so as to supply secondary air to an exhaust gas system of the small-sized motorcycle 1 through the secondary air supplying pipe 37 having the check valve 36 placed at its midway part. In addition, the check valve "36 is provided at the muffler 28. [Chosen Drawing] Fig. 1
Full Text [Detailed Description of the Invention]
[Technical Field of the Invention]
This invention relates to a device for supplying secondary air to an exhaust gas system of an internal combustion engine in order to purify exhaust gas in a small-sized motorcycle such as a scooter or the like.
(Prior Art]
As the secondary air supplying device for a small-sized motorcycle such as a conventional scooter or the like, there are provided a system in which an air cleaner (an air cleaner for an exhaust gas system) for purifying secondary air supplied to an exhaust gas system is fixed to a vehicle body frame and further having a
check valve (a reed valve) fixed to the internal combustion engine (gazettes of Japanese Patent Laid-Open Nos hei supply indian equivalent 5-139364, 5-131969 and 5-332132) and
ther system in which an air cleaner for the exhaust gas system and a check valve are fixed to a storing box below a seat (a gazette of Japanese Patent Laid-Open No. Hei 4-47114) or the like.
[Problems to be Solved by the Invention]
In the aforesaid prior art secondary air supplying device, either a secondary air supplying pipe part connecting an air cleaner for an exhaust gas system fixed to the vehicle frame with a check valve fixed to the internal combustion engine or another secondary air supplying pipe for connecting the air cleaner for the exhaust gas system fixed to a storing box and the check valve with the exhaust gas system (a connecting part of the secondary air supplying pipe) had to be formed long with its certain looseness (a bent part) being applied in such a way that the expansion or retraction caused by oscillation of the internal combustion engine unit could be absorbed. In addition, when a maintenance work for the secondary air supplying device such as the air cleaner for the exhaust gas system or the check valve was carried out, fixing or removal of the body cover was
required.
Further, in the case that the air cleaner for the exhaust gas system was fixed to either the body frame or the storing box, it was frequently found that the air cleaner was installed in a vacant space among the vehicle body frame, the storing box and the body cover and in this case, setting of a shape and a volume of the air cleaner for the exhaust gas system was restricted. Then, for example, if the air cleaner for the exhaust gas system was set to have a shape with many flat planes under such a restriction as above, the planes were vibrated to generate noise, resulting in that they were disadvantage.
[Means for Solving the Problems and Effects]
This invention relates to an improvement of the secondary air supplying device for the exhaust gas system of a small-sized motorcycle resolving the aforesaid problems and the invention described in Claim 1 consists in a secondary air supplying device for an exhaust gas system of a small-sized motorcycle in which secondary air is supplied to the exhaust gas system of the small-sized motorcycle through a secondary air supplying pipe of which extremity end is connected to the air
cleaner for the exhaust gas system and having a check valve installed at the midway part thereof characterized
in that said air cleaner for the exhaust gas system is

arranged at a muffler.
Since the invention described in Claim 1 is constructed as described above, the air cleaner for the exhaust gas system is arranged to be exposed out of the body cover, resulting in that when a maintenance work for the air cleaner is carried out, it does not become necessary to fix or remove the body cover. In addition, its shape and volume can be freely set and for example, they can be set to such a shape and a volume as one suitable for an effect of muffling action and the effect of muffling of sound of exhaust gas or sound of vibration of the internal combustion engine transmitted to the air cleaner for the exhaust gas system can be improved.
In addition, the invention described in Claim 1 is constructed as described in Claim 2, resulting in that the air cleaner for the exhaust gas system and the check valve are oscillated together with the muffler which is a part of the oscillating internal combustion engine unit, so that it does not become necessary that the secondary air supplying pipe connecting between each of the air
cleaner for the exhaust gas system, the check valve and the exhaust gas system (a connecting part of the secondary air supplying pipe) is formed to enable its expansion or retraction caused by oscillation of the internal combustion engine unit and then a length of each of the sections and an entire length of the elements can be made short.
In addition, since the air cleaner for the exhaust gas system and the check valve are arranged together at the muffler, the entire secondary air supplying device can be arranged in a compact size. Further, the air cleaner for the exhaust gas system and the check valve are arranged to be exposed out of the body cover, resulting- in that it does not become necessary that when a maintenance work for these members is carried out, the body cover is fixed or removed.
Additionally, since the check valve is arranged in a spaced-apart relation from the internal combustion engine, it may not be influenced by a thermal damage.
In addition, the invention described in Claim 3 consists in a secondary air supplying device for an exhaust gas system of a small-sized motorcycle in which secondary air is supplied to the exhaust gas system of
the small-sized motorcycle through a secondary air supplying pipe of which extremity end is connected to the air cleaner for the exhaust gas system and having a check valve installed at the midway part thereof characterized in that said check valve is arranged at a muffler.
Since the invention described in Claim 3 is constructed as described above, the check valve is arranged to be exposed out of the body cover and its maintenance characteristic is improved. In addition, since the check valve is oscillated together with the muffler which is a part of the oscillating internal combustion engine unit, it does not become necessary that the secondary air supplying pipe part connecting the check valve with the exhaust gas system (a connecting part of the secondary air supplying pipe) is formed to enable its expansion or retraction caused by oscillation of the internal combustion engine to be absorbed and then its length can be made short. Further, since the check valve is arranged in a spaced-apart relation against the internal combustion engine, it may not be influenced by the thermal damage of the engine.
Further, the invention described in Claim 3 is
constructed as described in Claim 4, the air cleaner for the exhaust gas system is oscillated together with the power transmitting device which is a part of the oscillating internal combustion engine unit, resulting in that it does not become necessary that the secondary air supplying pipe part connecting the air cleaner for the exhaust gas system with the check valve is formed to enable its expansion or retraction caused by oscillation of the internal combustion engine unit to be absorbed, its length can be made short and further an entire length of the secondary air supplying pipe can be made short.
Additionally, the invention described in Claim 3 is constructed as described in Claim 5 to cause the air cleaner for the exhaust gas system to be easily formed. In addition, since a single air cleaner case or a fixing stay or the like is not required, it is possible to reduce the number of component parts.
Further, since the air cleaner for the exhaust gas system is also oscillated together with the air cleaner for the intake gas system which is a part of the oscillating internal combustion engine unit, resulting in that it does not become that the secondary air
supplying pipe part connecting the air cleaner for the exhaust gas system with the check valve is formed to enable its expansion or shrinkage caused by oscillation of the internal combustion engine unit to be absorbed, its length can be made short and further an entire length of the secondary air supplying pipe can be made short.
Further, the invention described in Claim 5 is constructed as described in Claim 6, thereby a mere passing of the extremity end of the secondary air supplying pipe through the case of the air cleaner for the intake air system and connecting to it enables the purified secondary air for the exhaust gas system to be attained, so that forming of the air cleaner for the exhaust gas system is further facilitated.
In addition, the invention described in Claim 5 is constructed as described in Claim 7, thereby a mutual interference between the supplying system for the secondary air supplied to the exhaust gas system and the supplying system for primary air supplied to the intake air system is prevented.
Further, the invention described in Claim 7 is constructed as described in Claim 8, thereby a forming
of each of air intake ports between the air cleaner for the exhaust gas system and the air cleaner for intake air system may easily be carried out.
Additionally, the invention described in Claim 7 is constructed as described in Claim 9, thereby a mutual interference between the supplying system for secondary air supplied to the exhaust gas system and the supplying system for primary air supplied to the intake gas system is prevented further well.
In addition, the invention described in Claim 3 is constructed as described in Claim 10, thereby it is possible to fix the air cleaner for the exhaust gas system to the vehicle frame in a rigid manner and at the same time it is possible to keep outer appearance characteristics of the muffler and the air cleaner for the intake gas system.
Further, the invention described in Claim 3 is constructed as described in Claim 11, thereby the air cleaner for the exhaust gas system is oscillated together with the internal combustion engine, resulting in that it does not become necessary that the secondary air supplying pipe part connecting the air cleaner for the
exhaust gas system with the check valve is formed to enable its expansion or retraction caused by oscillation of the internal combustion engine unit to be absorbed, its length can be made short and further an entire length of the secondary air supplying pipe can be made short.
Additionally, it is possible that the air cleaner for the exhaust gas system is arranged at the shroud of the internal combustion engine at the same location as that where the main body of the muffler is present, thereby the air cleaner for the exhaust gas system and the check valve can be arranged to be near from each other, resulting in that the entire secondary air supplying device can be arranged in compact manner.
Further, the invention described in Claim 11 is constructed as described in Claim 12, thereby a formation of the air cleaner for the exhaust gas system may become easy. In addition, it does not necessary to have a single air cleaner case or a fixing stay or the like, it is possible to reduce the number of component parts.
Additionally, the invention described in Claim 13 consists in a secondary air supplying device for an exhaust gas system of a small-sized motorcycle in which
secondary air is supplied to the exhaust gas system of the small-sized motorcycle through a secondary air supplying pipe of which extremity end is connected to the air cleaner for the exhaust gas system and having a check valve installed at the midway part thereof characterized in that both said air cleaner for the exhaust gas system and said check valve are arranged below a floor section.
Since the invention described in Claim 13 is constructed as described above, it is possible that the air cleaner for the exhaust gas system and the check valve are arranged together near the hanger link for the internal combustion engine, thereby a length of the secondary, air supplying pipe can be made shorthand at the same time the entire secondary air supplying device can be made compact.
Further, the invention described in Claim 13 is constructed as described in Claim 15, thereby a length of the secondary air supplying pipe can be made shorter.
Further, the invention described in any of Claims 1 to 14 is constructed as described in Claim 15, thereby a maintenance work for the main body of the muffler, the
secondary air supplying device arranged at the main body of said muffler (the air cleaner for the exhaust gas system and the check valve) and the rear wheel or the like may be facilitated.
In addition, the invention described in any of Claims 1 to 15 is constructed as described in Claim 16, fixing or removal of the muffler, or the secondary air supplying device (the air cleaner for the exhaust gas system, the check valve) arranged at said muffler or below the floor section may easily be performed and concurrently even if these members are not removed completely from the vehicle, the maintenance work for these members as well as for the rear wheel may be performed more easily. Further, the vehicle can be made light in weight.
In addition, the invention described in any of Claims 1 to 16 is constructed as described in Claim 17, it is possible that the exhaust gas of the 2-cycle internal combustion engine is completely ignited, sufficiently purified and discharged.
Further, the invention described in any of Claims 1 to 17 is constructed as described in Claim 18, thereby

it is possible that an effect of sound muffling against the exhaust gas sound of the internal combustion engine or vibrating sound of the check valve transmitted to the air cleaner for the exhaust gas system is improved.
Accordingly the present invention relates to a secondary air supplying device for an exhaust gas system of a small-sized motorcycle in which secondary air is supplied to the exhaust gas system of the small-sized motorcycle through a secondary air supplying pipe of which extremity end is connected to the air cleaner for the exhaust gas system and having a check valve installed at the midway part thereof characterized in that said check valve is provided at a muffler.
[Brief Description of the Accompanying Drawings] [Fig. 1]
This is a side elevational view for showing a small-sized motorcycle provided with a secondary air supplying device for an exhaust gas system belonging to one preferred embodiment (a preferred embodiment 1) of the present invention described in Claims 1 to 3 and Claims 15 to 18. [Fig. 2]
This is a side elevational view partly in
longitudinal section in which a substantial part of Fig. 1 is enlarged. [Fig. 3]
This is a schematic top plan view partly in cross-section in which a substantial part of Fig. 1 (the internal combustion engine unit) is enlarged. [Fig. 4]
This is a side elevational view partly in longitudinal section for showing only the muffler part in Fig. 2. [Fig. 5]
This is a schematic top plan view partly in cross section for showing the internal combustion engine unit provided with the secondary air supplying device for the exhaust gas system belonging to one preferred embodiment (a preferred embodiment 2) of the present invention described in Claim 4 of the present invention and this figure corresponds to Fig. 3. [Fig. 6]
This is a schematic top plan view for showing the internal combustion engine unit provided with the secondary air supplying device for the exhaust gas system belonging to one preferred embodiment (a preferred embodiment 3) of the present invention described in Claims 5 and 6 of the present invention and this figure
corresponds to Fig. 3. [Fig. 7]
This is a top plan view in cross section for showing a case part of the air cleaner in Fig. 6. [Fig. 8]
This is a schematic top plan view for showing the internal combustion engine unit provided with the secondary air supplying device for the exhaust gas system belonging to one preferred embodiment (a preferred embodiment 4) of the present invention described in Claims 7 and 8 of the present invention and this figure corresponds to Fig. 3. [Fig. 9]
This is a top plan view in cross section for showing a case part of the air cleaner in Fig. 8. [Fig. 10]
This is a top plan view in cross section for showing a case part of an air cleaner in the secondary air supplying device for the exhaust gas system belonging to one preferred embodiment (a preferred embodiment 5) of the present invention described in Claim 9 of the present invention and this figure corresponds to Fig. 9. [Fig. 11]
This is a side elevational view for showing a
small-sized motorcycle provided with the secondary air supplying device for the exhaust gas system belonging to one preferred embodiment (a preferred embodiment 6) of the present invention described in Claim 10 of the present invention. [Fig. 12]
This is a schematic top plan view for showing a part of the internal combustion engine unit provided with the secondary air supplying device for the exhaust gas system belonging to one preferred embodiment (a preferred embodiment 7) of the present invention described in Claim
11 of the present invention.
[Fig. 13]
This is a side elevational view for showing a
substantial part as seen from a direction XIII in Fig.
12 with a part thereof being cut-away.
[Fig. 14]
This is a side elevational view for showing a substantial part of the secondary air supplying device for the exhaust gas system belonging to one preferred embodiment (a preferred embodiment 8) of the present invention described in Claim 12 of the present invention with a part thereof being cut-away and this figure corresponds to Fig. 13. [Fig. 15]
This is a side elevational view for showing a small-sized motorcycle provided with the secondary air supplying device for the exhaust gas system belonging to one preferred embodiment (a preferred embodiment 9) of the present invention described in Claims 13 and 14 of the present invention. (Fig. 16}
This is a schematic top plan view partly in cross-section in which a substantial part of Fig. 15 is enlarged and this figure corresponds to Fig. 3. [Fig. 17]
This is similar to Fig. 15 showing an example of modification of a preferred embodiment (a preferred embodiment 9) shown in Fig. 15
[Preferred Embodiments of the Invention]
At first, one preferred embodiment of the invention (a preferred embodiment 1) described in Claims 1 to 3 and Claims 15 to 18 shown in Figs.l to 4 will be described as follows.
In these figures, 1 denotes a scooter type motorcycle in which a secondary air supplying device is applied to an exhaust system of a preferred embodiment 1 of the present invention illustrated in a left side elevational view, and 2 denotes a seat in which a steering head 4 is raised with a low floor section 3 being spaced apart at a front part of the seat.
A handle turning shaft 6 turned by a handle 5 is pivotally supported at a head pipe 7 and a front wheel

9 is suspended at the lower end of the shaft through a front fork 8. Then, a down-frame 10 is extended from the head pipe 7 to a downward direction, branched at its lower section into a right side and a left side to extend at the floor section 3 to a rearward direction and then the
down-frame is connected to a ree.r frame 11. The rear frame 11 is extended in a slant upward and rearward direction and reaches the lower part of the rear end of the seat 2.
The front section of a vehicle body of which frame-work is formed by these down-frame 10 and rear frame 11 is provided with a leg shield 12 covering the rear section of the down-frame 10 and extending along this rear section, wherein the leg shield 12 is extended in a rearward and downward direction and connected to a floor cover 13 covering a central floor section of the vehicle body. Then, the floor cover 13 is connected to the body cover 14 covering the rear extended section of the rear frame 11 where it is raised from its horizontal section to the slant rear section, the body cover 14 is connected to a center cover 15 at its front upper section and the center cover 15 covers, together with the front seat 2, the front section of a fuel tank 16 stored below the seat 2.
17 denotes an internal combustion engine unit (a swing unit) for use in suspending a rear wheel, wherein its front section is attached to the front lower section of the rear frame 11 through a hanger link 18 in such
a way that it may be oscillated in an upward or downward direction and its rear section is suspended at the rear section of the rear frame 11 through a cushion unit 19.
At the front section of the internal combustion unit 17 is integrally arranged an internal combustion engine 20 and at its rear section is pivotally arranged a rear wheel 21. Then, a power transmitting device (a belt continuously variable transmission) 22 for use in transmitting a power of the internal combustion engine 20 to the rear wheel 21 and a muffler 28 which is one element constituting an exhaust gas system to be described later are integrally arranged at the internal combustion engine unit 17 with the rear wheel 21 being held between them.
The internal combustion engine 20 is a 2-cycle internal combustion engine, wherein an intake system comprised of an air cleaner 23, a carburetor 24 and an intake pipe 25 is connected to an intake port (not shown) of the internal combustion engine 20.
The exhaust pipe 27 is extended from an exhaust port 26 arranged at a cylinder section of the internal combustion engine 20 in a forward and downward direction, thereafter curved and directed in a rearward direction,
a main body 30 of a muffler is cooperatively connected to its rear part and the muffler 28 is constituted by these members.
The exhaust pipe 27 and the main body 30 of the muffler are removably connected at a connecting part 31 in such a way that flanges of each of them are removably connected by a coupling means comprised of a bolt and a nut.
As shown in Fig. 2, within the main body 30 of the muffler is stored a catalyst converter 32 composed of metallic catalyst, wherein exhaust gas fed by the exhaust pipe 27 performs an oxidization reaction in the catalyst converter 32 to become complete combustion gas and the gas is discharged into the surrounding atmosphere while being purified.
To the aforesaid exhaust system is fed secondary air in addition and an effect of purifying exhaust gas with the aforesaid catalyst converter 32 is improved. This secondary air is supplied from a secondary air inlet port 34 formed relatively near a section connected to the exhaust port 26 of the internal combustion engine 20 through a secondary air supplying system to be described later.
The aforesaid secondary air supplying system is comprised of an air cleaner 35 for an exhaust system/ a check valve composed of a reed valve 36, and a secondary air supplying pipe 37 connecting these members and further connecting them to the aforesaid secondary air feeding inlet 34. The secondary air supplying pipe 37 is comprised of a flexible rubber hose 38 connecting the air cleaner 35 for the exhaust system to the reed valve 36, a flexible rubber hose 39 at the side of the reed valve 36 connecting the reed valve 36 to the secondary air feeding inlet 34, and a metallic pipe 40 at the secondary air feeding inlet 34.
The rubber hose 38 can be separated at connecting sections 37a, 37b and further the hose is removably arranged in respect to the reed valve 36 at a connecting part 37d with the reed valve 36. The rubber hose 39 is also removably arranged in respect to the reed valve 36 at the connecting part 37e with the reed valve 36. In addition, the rubber hose 3y and the metallic pipe 40 are removably arranged at a connecting part 37c placed at a substantial intermediate point between the reed valve 36 and the secondary air feeding inlet port 34.
The aforesaid air cleaner 35 for the exhaust system is fixed to the rear section of a cockscomb-like vertical fixing piece 41 (refer to Fig. 4) fixed vertically at a top end of the main body 30 of the muffler with its air suction inlet 35a being directed in a forward and downward direction by some fixing means 42 composed of bolts and nuts, wherein a side of a clean chamber 35b within the air purifying chamber is divided by a partition plate 35c into two chambers, both chambers are communicated by a communicating pipe 35d, air purified by a filter 35e passes through these two chambers, exits out of an outlet port 35f and is guided to a rubber hose 38 of the secondary air supplying pipe 37.
The aforesaid reed valve 36 is fixed, by connecting means 44 composed of bolts and nuts, to the two front and rear arms 43a, 43b extended out in a horizontal direction of the fixing piece 43 fixed to a forward wide section of the vertical fixing piece 41.
Then, these air cleaner 35 for exhaust system and the reed valve 36 are thermally shielded by the muffler cover 45 against the main body 30 of the muffler. The aforesaid muffler cover 45 is fixed to the main body 30 of the muffler in a predetermined clearance while a slit part 45a at its top section is being fitted to a welded
leg 41a of the vertical fixing piece 41.
Since the preferred embodiment 1 is constructed as described above, both the air cleaner 35 and the reed valve 36 for the exhaust system are arranged to be exposed out of the body cover 14, it does not become necessary to fix or remove the body cover 14.
In addition, it becomes possible to make a free setting of both shape and volume of the air cleaner 35 for the exhaust system and exhaust sound of the internal combustion engine transmitted to the air cleaner 35 for the exhaust system or vibration sound of the reed valve 36 can be effectively muffled by making its shape into a cylindrical shape or increasing its volume or dividing the clean chamber 35b in the chamber into a plurality of chambers communicated in series.
Additionally, both the air cleaner 35 and the reed valve 36 for the exhaust system are oscillated together with the oscillating main body 30 of the muffler of a part of the internal combustion engine unit 17, so that it does not become necessary to form each of sections 38, 39, 40 of the secondary air supplying pipe 37 connecting the air cleaner 35, reed valve 36 for the
exhaust system and the secondary air feeding inlet port 34 in such a way that it may absorb expansion or retraction caused by the internal combustion engine unit 17 and so a length of each of the sections 38, 39 and 40 and an entire length of them can be made short.
Further, since both the air cleaner 35 and the reed valve 36 for the exhaust system are arranged altogether at the main body 30 of the muffler, it is possible to arrange the entire secondary air supplying device in a compact manner.
In addition, since the reed valve 36 is arranged in a spaced apart relation against the internal combustion engine 20, there is no possibility that it may be thermally damaged by the engine.
Further, in the case that the main body 30 of the muffler, the secondary air supplying device (the air cleaner 35 for the exhaust system and the reed valve 36) arranged at the aforesaid main body 30 of the muffler and the rear wheel 21 or the like are repaired and maintained, the main body 30 of the muffler can be removed together with the secondary air supplying device, the rear wheel 21 can be removed so as to enable their works to be easily carried out due to the fact that the main
body 30 of the muffler is formed such that it may be freely fixed or removed together with the exhaust pipe 27.
In this case, since the rubber hose 39 is removably arranged at the connecting part 37c against the metallic pipe 40, the rubber hose 39 is removed from the metallic pipe 40 or the connected state at the connecting part 37e is released so as to cause the rubber hose 39 to be removed from the reed valve 36, thereby the main body 30 of the muffler and the secondary air supplying device arranged at the main body 30 of the muffler can be completely separated from the vehicle. With such an arrangement as above, the aforesaid maintenance work can be performed more easily.
Since the rubber hose 39 has a flexibility, the aforesaid maintenance work can be performed easily even if the main body 30 of the muffler and the secondary air supplying device arranged at the main body 30 of the muffler are not completely separated as described above.
In addition, since the metallic catalyst is stored in the main body 30 of the muffler, it is possible to perform a complete combustion of exhaust gas full of not-yet-ignited substances discharged from the 2-cycle internal combustion engine 20 through the metallic
catalyst and secondary air supplied to the exhaust gas system, and to carry out a sufficient purification of it as well as its discharging operation.
Then, one preferred embodiment of the present invention (the preferred embodiment 2) described in Claim 4 of the present invention illustrated in Fig. 5 will be described.
In the preferred embodiment 2, the air cleaner 35 for the exhaust gas system in the secondary air supplying device is fixed and arranged on the case of a power transmission device (a belt continuously variable transmission) 22 across the air cleaner 23 for an intake system through connecting means of bolts and nuts not shown. Since other configurations are similar to those of the preferred embodiment 1, their detailed description will be eliminated.
Since the preferred embodiment 2 is constructed as described above, the air cleaner 35 for the exhaust gas system can be oscillated also in this case together with the power transmitting device 22 which is a part of the oscillating internal combustion engine unit 17. Accordingly, a secondary air supplying pipe part (a rubber hose) 38 for connecting the air cleaner 35 with
the reed valve 36 for the exhaust gas system is not necessary to be formed in such a way that its expansion or retraction caused by oscillation of the internal combustion engine unit 17 may be absorbed, its length can be shortened and further an entire length of the secondary air supplying pipe 37 can be shortened.
Then, one preferred embodiment (the
preferred embodiment 3) described in Claim 5 and Claim 6 of the present invention illustrated in Figs.6 and 7 will be described.
In the preferred embodiment 3 of the present invention, the air cleaner 35 for the exhaust gas system in the secondary air supplying device is integrally formed with the air cleaner 23 for an intake gas system under a cooperative application of one air cleaning chamber 23a. Since other configurations are similar to those of the preferred embodiment 1, their detailed description will be eliminated. In addition, 23e denotes an air intake port.
Since the preferred embodiment 3 of the present invention is constructed as described above, mere passing of the extremity end of the secondary air supplying pipe section (the rubber hose) 38 through the inner case 23b of the air cleaner 23 for the intake gas system and connecting to it enables the purified
secondary air for the exhaust gas system to be attained, so that forming of the air cleaner 35 for the exhaust gas system becomes quite easily, either a single air cleaner case or a fixing stay or the like is not required and the number of component parts can be reduced. In addition, 23c denotes an outer case for the air cleaner for air intake system.
In addition, also in this case, the air cleaner 35 for the exhaust gas system can be oscillated together with the air cleaner 23 for the intake gas system which is a part of the oscillating internal combustion engine unit 17. Accordingly, a secondary air supplying pipe part (a rubber hose) 38 for connecting the air cleaner 35 for the exhaust gas system with the reed valve 36 is not necessary to be formed in such a way that its expansion or retraction caused by oscillation of the internal combustion engine unit 17 may be absorbed, its length can be shortened and further an entire length of the secondary air supplying pipe 37 can be shortened.
Then, one preferred embodiment (the
preferred embodiment 4) described in Claim 7 and Claim 8 of the present invention illustrated in Figs. 8 and 9 will be described.
In the preferred embodiment 4 of the present invention which is different from the preferred
embodiment 3, the air cleaner 35 for the intake gas system in the secondary air supplying device is integrally formed with the air cleaner 23 for an intake gas system while each of the air purifying chambers 35g, 23d is being separated from each other. Then, these air purifying chambers 35g, 23d have a common air suction inlet 23e. 23f denotes a partition wall for separating these both air purifying chambers 35g, 23d. 23g denotes a filter arranged across both air purifying chambers 35g, 23d. Other configurations are similar to those of the preferred embodiment 3, their detailed description will be eliminated.
Since the preferred embodiment 4 of the present invention is constructed as described above, a mutual interference is prevented between a system for supplying secondary air supplied to the exhaust gas system for purifying the exhaust gas of the internal combustion engine 20 and a system for supplying primary air supplied to the intake gas system as combustion air for the internal combustion engine 20.
In addition, each of the air intake ports between the air cleaner 35 for the exhaust gas system and the air cleaner 23 for the intake gas system may easily be formed.
Then, one preferred embodiment (a
preferred embodiment 5) described in Claim 9 of the present invention illustrated in Fig. 10 will be described.
In the preferred embodiment 5 of the present invention which is different from the preferred embodiment 4, aforesaid both air purifying chambers 35g, 23d have separate air intake ports 35h, 23h. Due to this fact, both air purifying chambers 35g, 23d are completely separated by a partition wall 23i vertically arranged at a common inner case 23b and a partition wall 23j vertically arranged at a common outer case 23c.
In addition, a filter 35i for the air
cleaner 35 for an exhaust gas system and a filter 23k for the air cleaner 23 for the intake gas system are separately arranged and their inner ends are held and supported by grooves formed at the extremity end of the partition wall 23i in an opposite direction as illustrated in the figure. Since other configurations are similar to those of the preferred embodiment 4, their detailed description will be eliminated.
Since the preferred embodiment 5 is
constructed as described above, a mutual interference between the secondary air supplying system and the primary air supplying system is further more prevented.
Then, one preferred embodiment (a preferred embodiment 6) described in Claim 10 of the present invention illustrated in Fig. 11 will be described.
In the preferred embodiment 6 of the present invention which is different from the preferred embodiments 1 to 5, the air cleaner 35 for the exhaust gas system in the secondary air supplying device is connected to and arranged at the rear frame 11 by connector means 46 using bolts and nuts or the like in such a way that the air cleaner may be arranged in a vacant space between the shroud 47 for the internal combustion engine 20 and the body cover 14. Then, the air cleaner 35 for the exhaust gas system and the reed valve 36 are connected by the secondary air supplying pipe section (a rubber hose) 38. Since other configurations- are similar to those of the preferred embodiment 1, their detailed description will be eliminated.
Since the preferred embodiment 6 of the present invention is constructed as described above, it is possible to fix the air cleaner 35 for the exhaust gas system to the rear frame 11 in a rigid manner. In addition, outer appearance characteristics of the main body 30 of the muffler and the air cleaner 23 for the intake gas system are not damaged.
Then, one preferred embodiment (a preferred embodiment 7) of the present invention described in Claim 11 illustrated in Figs.12 and 13 will be described.
In the preferred embodiment 7 of the present invention which is different from the preferred embodiments 1 to 6, the air cleaner 35 for the exhaust gas system in the secondary air supplying device is fixed to and arranged at the right side surface of the shroud 47 of the internal combustion engine 20 by a connecting means 48 using a bolt and a nut. Since other configurations are similar to those of the preferred embodiment 1, their detailed description will be eliminated.
Further, the shroud 47 covers the cylinder part of the internal combustion engine 20, and surrounding atmosphere is sucked from a cold air intake port formed at either the front surface or the left side surface by a fan and flows in the shroud 47 so as to forcedly cool the cylinder part (not shown).
Since the preferred embodiment 7 of the present invention is constructed as described above, the air cleaner 35 for the exhaust gas system can be oscillated
together with the internal combustion engine 20. Accordingly, it does not become necessary that the secondary air supplying pipe section (a rubber hose) 38 for use in connecting the air cleaner 35 for the exhaust gas system to the reed valve 36 is formed to enable an expansion or retraction of it due to oscillation of the internal combustion engine unit 17 to be absorbed, resulting in that its length can be made short and further an entire length of the secondary air supplying pipe 37 can be made short.
Further, the air cleaner 35 for the exhaust gas system is arranged at the right side surface of the shroud 47 placed at the same side as that of the main body 30 of the muffler, it is possible that the air cleaner 35 for the exhaust gas system and the reed valve 36 are arranged to be approached to each other and further the entire secondary air supplying device can be arranged in a compact size.
Then, one preferred embodiment (a preferred embodiment 8) of the present invention described in Claim 12 illustrated in Fig. 14 will be described.
In the preferred embodiment 8 of the present invention which is different from the preferred
embodiment 7, the air cleaner 35 for the exhaust gas system in the secondary air supplying device is formed and arranged integrally at the outer wall of the shroud 47 of the internal combustion engine 20.
Due to this fact, an inner case 35j of the air cleaner 35 for the exhaust gas system is integrally formed with the case of the shroud 47 of the internal combustion engine 20. The outer case 35k is separately formed in order to facilitate fixing of and maintenance of the filter 351. Since other configurations are similar to those of the preferred embodiment 7, their detailed description will be eliminated.
The preferred embodiment 8 of the present invention is constructed as described above, it becomes easy to form the air cleaner 35 for the exhaust gas system. In addition, since it is not necessary to prepare a single air cleaner or a fixing stay or the like, it is possible to reduce the number of component parts.
Then, one preferred embodiment (a preferred embodiment 9) of the present invention described in Claims 13 and 14 illustrated in Figs.14 to 17 will be described.
In the preferred embodiment 9 which is different from the preferred embodiments 1 to 8 , the air cleaner 35 for the exhaust gas system and the reed valve 36 in the secondary air supplying device are fixed to and arranged at a horizontal extension part of a down-frame 10 below the floor 3 by a connecting means (not shown) using a stay extending from the down-frame 10, a bolt and a nut.
Then, a secondary air supplying pipe 37 for use in connecting the air cleaner 35 for the exhaust gas system and the reed valve 36 to a secondary air intake port 34 formed at the exhaust gas pipe 27 of the internal combustion engine 20 (refer to Fig. 16) is arranged to pass through a location near the hanger ring 18 for the internal combustion engine unit 17.
In this case, Figs. 15 and 16 illustrate a state in which the present device is applied to a small-sized motorcycle provided with a vertical internal combustion engine 20 slightly inclined from its vertical line to a rearward direction, and Fig. 17 illustrates another state in which the present device is applied to a small-sized motorcycle provided with a horizontal internal combustion engine 20 slightly raised from its
horizontal level and arranged, respectively.
In the preferred embodiment 9, in the case that a maintenance work for the air cleaner 35 for the exhaust gas system or the reed valve 36 is carried out, an under-cut 50 (Figs.15, 17) is removed from the vehicle.
Since the present preferred embodiment 9 is constructed as described above, it is possible that the air cleaner 35 for the exhaust gas system and the reed valve 36 are arranged together near the hanger link 18 of the internal combustion engine unit 17, thereby it is possible to shorten a length of the secondary air supplying pipe 37. In addition, the entire secondary air supplying device can be arranged in compact.
[Description of the Reference Numerals]
1: scooter type motorcycle
2:seat
3 i floor
section
4: steering head 5: handle 6: handle turning
shaft
7: head pipe 8: front fork 9: front wheel 10: down-frame 11: rear frame 12: leg shield 13: floor cover 14: body cover 15: center cover 16: fuel tank 17: internal combustion engine unit (swing unit)
18: hanger link 19: cushion unit
20: internal combustion engine 21: rear wheel 22: power transmitting device (belt continuously
variable transmission)
23: air cleaner for an intake gas system
23a, 23d: air purifying chamber 23e, 23h: air
intake port
24: carburetor 25: air intake pipe 26: exhaust
gas port
27: exhaust gas pipe (part) 28: muffler
30: main body of muffler 31: connecting part
32: catalyst converter 34: secondary air feeding
port
35: air cleaner for exhaust gas system 35b: clean
chamber
35g: air purifying chamber 35h: air inlet port. 36: reed valve (check valve) 37: secondary air
supplying pipe
38, 39: flexible rubber hose 40: metallic pipe 41: vertical fixing piece 42: connecting means 43: fixing piece 44: connecting means 45: muffler cover 46: connecting means 47: shroud 48: connecting means 49: side cover 50: under-cover





Claim:
1. A secondary air supplying device for an exhaust gas system of a
small-sized motorcycle in which secondary air is supplied to the
exhaust gas system of the small-sized motorcycle through a secondary
air supplying pipe of which extremity end is connected to the air
cleaner for the exhaust gas system and having a check valve installed
at the midway part thereof characterized in that said check valve is
provided at a muffler.
2. A secondary air supplying device for an exhaust gas system of a
small-sized motorcycle as claimed in claim 1, wherein secondary air is
supplied to the exhaust gas system of the small-sized motorcycle
through a secondary air supplying pipe of which extremity end is
connected to the air cleaner for the exhaust gas system and having a
check valve installed at the midway part thereof wherein said air
cleaner for the exhaust gas system is disposed at a muffler.
3. A secondary air supplying device for an exhaust gas system of a
small-sized motorcycle as claimed in claim 1 wherein said air cleaner
for the exhaust gas system is provided side-by-side on a case of a
power transmitting device across the air cleaner for an intake gas
system.
4. A secondary air supplying device for an exhaust gas system of a
small-sized motorcycle as claimed in claim 1 wherein said air cleaner
for the exhaust gas system is integrally formed with said air cleaner
for the intake gas system.
5 A secondary air supplying device for an exhaust gas system of a small-sized motorcycle as claimed in claim 4, wherein said air cleaner

for the exhaust gas system is integrally formed with said air cleaner for the intake gas system in cooperation with one air purifying chamber.
6 A secondary air supplying device for an exhaust gas system of a small-sized motorcycle as claimed in claim 4, wherein said air cleaner for the exhaust gas system is integrally formed with said air cleaner for the intake gas system with each of air purifying chambers being separated from each other.
7. A secondary air supplying device for an exhaust gas system of a small-sized motorcycle as claimed in claim 6 wherein each of said air purifying chambers has a common air intake port.
8 A secondary air supplying device for an exhaust gas system of a
small-sized motorcycle as claimed in claim 6, wherein each of said air
purifying chambers has a separate air intake port.
9 A secondary air supplying device for an exhaust system of a small-
sized motorcycle as claimed in claim 1, wherein said air cleaner for
the exhaust system is provided at the rear frame.
10 A secondary air supplying device for an exhaust gas system of a
small-sized motorcycle as claimed in claim 1, wherein said air cleaner
for the exhaust gas system is provided at a shroud of an internal
combustion engine.
11. A secondary air supplying device for an exhaust gas system of a small-sized motorcycle as claimed in claim 2, wherein said air cleaner for the exhaust gas system is integrally formed with a shroud of said internal combustion engine.

12. A secondary air supplying device for an exhaust gas system of a
small-sized motorcycle as claimed in any of the preceding claims
wherein the said muffler is comprised of the main body of the muffler
and the exhaust gas pipe and these main body of the muffler
and the exhaust gas pipe are removably formed.
13. A secondary air supplying device for an exhaust gas system of a
small-sized motorcycle as claimed in any of the preceding claims
wherein said secondary air supplying pipe ranging from said check
valve to said exhaust gas system is formed by connecting a flexible
hose at said check valve with a metallic pipe at said exhaust gas
system.
14 A secondary air supplying device for an exhaust gas system of a small-sized motorcycle as claimed in any of the preceding claims wherein the internal combustion engine is a 2-cycle internal combustion engine and catalyst is stored in the muffler.

15. A secondary air supplying device for an exhaust gas system of a
small-sized motorcycle as claimed in any of the preceding claims
wherein said air cleaner for exhaust gas system is formed with a clean
chamber side in its chamber being divided into a plurality of
chambers communicated in series.
16. A secondary air supplying device substantially as herein described
with reference to the accompanying drawings.



Documents:

421-del-1998-abstract.pdf

421-del-1998-claims.pdf

421-del-1998-correspondence-others.pdf

421-del-1998-correspondence-po.pdf

421-del-1998-description (complete).pdf

421-del-1998-drawings.pdf

421-del-1998-form-1.pdf

421-del-1998-form-13.pdf

421-del-1998-form-19.pdf

421-del-1998-form-2.pdf

421-del-1998-form-3.pdf

421-del-1998-form-4.pdf

421-del-1998-form-6.pdf

421-del-1998-gpa.pdf

421-del-1998-petition-137.pdf

421-del-1998-petition-138.pdf


Patent Number 215472
Indian Patent Application Number 421/DEL/1998
PG Journal Number 11/2008
Publication Date 14-Mar-2008
Grant Date 27-Feb-2008
Date of Filing 18-Feb-1998
Name of Patentee HONDA GIKEN KOGYO KABUSHIKI KAISHA,
Applicant Address 1-1, MINAMITAOYAMA 2-CHOME, MINATO-KU, TOKYO, JAPAN
Inventors:
# Inventor's Name Inventor's Address
1 MASAKI YOKOYAMA C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, OF 4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA, JAPAN
2 KENSUKE SUZUKI C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, OF 4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA, JAPAN
3 TAKAAKI FUJII C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, OF 4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA, JAPAN
4 NOBORU YOKOYA C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, OF 4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA, JAPAN
PCT International Classification Number F01N 3/34
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 HEI-9-107315 1997-04-24 Japan