Title of Invention

EXHAUST EMISSION CONTROL SYSTEM FOR MOTORCYCLE

Abstract An exhaust emission control system for a motorcycle comprising an exhaust system of an engine (E) which constitutes a power unit (P) in co-operation with a continuously variable transmission (M) and is swingably supported by a body frame (F), and a secondary air cleaner (83) for cleaning secondary air to be fed to said exhaust system, wherein said secondary air cleaner (83) is connected to said exhaust system via a check valve (117) characterized in that an inlet tube (121) with its one end connected to said secondary air cleaner (83) mounted on said power unit (P) extends from said secondary air cleaner (83).
Full Text
FORM 2 THE PATENTS ACT 1970 [39 OF 1970]
PROVISIONAL/COMPLETE SPECIFICATION
[See Section 10]
"EXHAUST EMISSION CONTROL SYSTEM 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 : -

429/MUM/2000GRANTED

-9-MAY 2000 15-6-2005

[Detailed Description of the Invention]
[Technical Field to Which the Invention Pertains] The present invention relates to an exhaust
emission control system for a motorcycle including an
exhaust system of an engine which constitutes a power unit in co-operation with a continuously variable transmission and is swingably supported by a body frame, and a secondary air cleaner for cleaning secondary air to be fed to the exhaust system, wherein the secondary air cleaner is connected to the exhaust system via a check valve.
[Prior Art]
The control system of this type has been known, for example, from Japanese Patent Laid-open No. Hei 5-131969
[Problem to be Solved by the Invention]
The above - described prior art control system, however, has the following problem; namely, since a




secondary air cleaner is mounted on a body frame, a connection work of the air cleaner to an exhaust system of an engine must be performed in a state in which a power unit and the secondary air cleaner are assembled on the body frame. As a result, the connection work of the air cleaner becomes complicated.
To solve such a problem, there may be adopted an assembling procedure of previously mounting the secondary air cleaner to the power unit and connecting the secondary air cleaner to the exhaust system of the engine, and then mounting the power unit to the body frame. The mounting of the secondary air cleaner to the power unit, however, has a problem that since it is impossible for the power unit to have a space being large enough to mount the secondary air cleaner, the capacity of the
secondary air cleaner must be minimized. As a result, for
the secondary air cleaner of a type in which an inlet
opened outwardly is provided in a cleaner case of the secondary air cleaner, not only suction sound becomes
large, but also the arrangement range of the inlet is
limited and the inlet is susceptible to water and mud
splashed by a rear wheel.
[0005]





In view of the foregoing, the present invention has been made, and an object of the present invention is to provide an exhaust emission control system for a motorcycle, which is capable of facilitating the connection work of a secondary air cleaner to an exhaust
system of an engine, reducing suction sound caused in the secondary air cleaner, and preventing the secondary air



cleaner from being affected by water and mud.
[Means for Solving the Problem]
To achieve the above object, according to an invention there is provided an

exhaust emission control system for a motorcycle including an exhaust system of an engine which constitutes a power unit in co-operation with a continuously variable transmission and is swingably supported by a body frame, and a secondary air cleaner for cleaning secondary air to be fed to the exhaust system, wherein the secondary air cleaner is connected to the exhaust system via a check valve, characterized in that an inlet tube with its one end connected to the secondary air cleaner mounted on the power unit extends from the secondary air cleaner.


With this configuration, since the secondary air cleaner is mounted to the power unit, it can be connected to the exhaust system of the engine before being assembled to the body frame. Accordingly, it is possible to facilitate the connection work of the secondary air cleaner to the exhaust system. Also, it is possible to increase the substantial capacity of the secondary cir cleaner by provision of the inlet tube, and further, it is possible to prevent the secondary air cleaner from being affected by water and mud by extending the inlet tube up to a suitable position.
According to an invention addition to the configuration of the invention described

easlier the inlet tube extends up to the lower side of a step floor of a body cover for covering the body frame by way of the vicinity of a shaft for swingably supporting the engine on the body frame. With this configuration, it is possible to suitably lay out the inlet tube while preventing the inlet tube from being applied with an external bending force or the like caused by swing motion of the power unit as much as possible.





According to an invention:





addition to the configuration of the invention
a box-like compartnent opened upwardly is
disposed under the step floor, and the other end of the inlet tube is opened in the compartment., With this configuration, it is possible to more, effectively reduce occurrence of suction sound, and to more effectively prevent the secondary air cleaner from being effecte.d by water and mud.

Accordingly, the present invention relates to An exhaust emission control system for a motorcycle comprising an exhaust system of an engine (E) which constitutes a power unit (P) in co-operation with a continuously variable transmission (M) and is swingably supported by a body frame (F), and a secondary air cleaner (83) for cleaning secondary air to be fed to said exhaust system, wherein said secondary air cleaner (83) is connected to said exhaust system via a check valve (117) characterized in that an inlet tube (121) with its one end connected to said secondary air cleaner (83) mounted on said power unit (P) extends from said secondary air cleaner (83).


[Mode for Carrying Out the Invention]
Hereinafter, one embodiment of the present invention will be described with reference to the
accompanying drawings..
1
[•Brief Description of the Drawings]
[Fig. 1]
A side view of a motorcycle.
[Fig. 2]
A view, seen along an arrow 2 of Fig. 1, showing
the motorcycle from which a body cover, a luggage box a
a fuel tank are omitted.
[Fig. 3]
A view, seen along an arrow 3 of Fig. 1, showing
,the motorcycle from which a step floor is omitted.
[Fig. 4]
A transverse sectional view of a power unit.
[Fig. 5]
An enlarged side view of an air cleaner and a
secondary air cleaner.

[Fig. 6]
A sectional view taken on line 6-6 of Fig. 5. [Fig. 7]
An enlarged sectional view taken on line 7-7 of Fig. 5.
[Fig. 8]
A side view, with parts partially cutaway, showing a portion for swingably supporting an engine on the body frame. [Fig. 9]
A sectional view taken on line 9-9 of Fig. 8. [Fig. 10]
An enlarged sectional view taken on line 10-10 of Fig. 2. [Fig. 11]
A sectional view taken on line 11-11 of Fig. 10.
Figs. 1 to 11 show one embodiment of the present invention, wherein Fig. 1 is a side view of a motorcycle; Fig. 2 is a view, seen along an arrow 2 of Fig. 1, showing the motorcycle from which a body cover, a luggage box and a fuel tank are omitted; Fig. 3 is a view, seen along an arrow 3 of Fig. 1, showing the motorcycle from which an upper cover is omitted; Fig. 4 is a transverse sectional view of a power unit; Fig. 5 is an enlarged side view of an air cleaner and a secondary air cleaner; Fig. 6 is a sectional view taken on line 6-6 of Fig. 5;


Fig. 7 is an enlarged sectional view taken on line 7-7 of Fig. 5; Fig. 8 is a side view, with parts partially cutaway, showing a portion for swingably supporting an engine on the body frame; Fig. 9 is a sectional view taken on line 9-9 of Fig. 8; Fig. 10 is an enlarged sectional view taken on line 10-10 of Fig. 2; and Fig. 11 is a sectional view taken on line 11-11 of Fig. 10.
Referring first to Fig. 1, a body frame F of a scooter-type motorcycle includes a front frame 11 formed from an aluminum alloy or the like by casting; a rear frame 12 formed from an aluminum alloy or the like and fastened to the rear end of the front frame 11; and a sub-frame 13 formed by working metal pipes and fastened to the rear end of the rear frame 12.
The front frame 11 includes at its front end a head pipe 14, and a front fork 17 lying astride a front wheel WF is steerably supported by the head pipe 14 . The lower ends of the front fork 17 are disposed in front of an axle 18 of the front wheel WF. One end of a link 19 is connected to the lower end of the front fork 17, and the other end of the link 19 is connected to the axle 18. A front cushion 20 is provided between an intermediate


portion of the front fork 17 in the vertical direction and an intermediate portion of the link 19. A steering handlebar 21 is connected to the upper end of the front fork 17.
Referring to particularly to Figs. 2 and 3, the front frame 11, which is formed by casting, integrally includes the head pipe 14, a down frame 15 extending rearwardly, downwardly from the head pipe 14, and a pair of right and left floor supporting frames 16 extending rearwardly from the lower end of the down frame 15. The rear frame 12 is fastened to the rear ends of the floor supporting frames 16.
A power unit P is composed of an engine E disposed on the front side of the rear wheel WR and a continuously variable transmission M disposed on the left side of the rear wheel WR. The power unit P is swingably supported via a vibration-proof link 22 by an intermediate portion of the rear frame 12 in the longitudinal direction. The engine E is configured as a water-cooled type single-cylinder/four- cycle engine disposed substantially in the horizontal direction with its cylinder directed forwardly of the vehicular body, and the transmission M is


configured as a belt-type transmission.

Referring to Fig. 4, the engine E includes a first
engine block 32 and a second engine block 33. The first
engine block 32 constitutes a cylinder block 32x and a
crank case half 322, and the second engine block 33
constitutes the other half of the crank case 29.
A cylinder head 34 is connected to the front end of the first engine block 32, and a cylinder head 35 is connected to the front end of the cylinder head 34. A generator cover 36 is connected to the right side surfaces of the first and second engine blocks 32 and 33.
The continuously variable transmission M includes a right casing 37 and a left casing 38 connected to each other. The right side surface of a front portion of the right casing 37 is connected to the left side surfaces of the first and second engine blocks 32 and 33. A reducer casing 39 is connected to the right side surface of a rear portion of the right casing 37.
A piston 42 slidably fitted in a cylinder 41 of the first engine block 32 is connected to a crank shaft 31


via a connecting rod 43 and a crank pin 28. A cam shaft
44 is rotatably supported by the cylinder head 34, and intake and exhaust valves (not shown) provided in the cylinder head 34 are opened/closed by the cam shaft 44. A timing chain 45 is contained in a chain passage 40 provided in the first engine block 32. The timing chain
45 is wound around a drive sprocket 46 provided on the crank shaft 31 and a driven sprocket 47 provided on the cam shaft 44. The cam shaft 44 makes one revolution per two revolutions of the crank shaft 31.

A drive pulley 54 is provided on the left end, projecting in the right casing 37 and the left casing 38, of the crank shaft 31. The drive pulley 54 includes a fixed pulley half 55 fixed to the crank shaft 31, and a movable pulley half 56 moved close to or apart from the fixed pulley half 55. The movable pulley half 56 is biased to be moved close to the fixed pulley half 55 by a centrifugal weight 57 which is moved radially outwardly along with an increase in rotational speed of the crank shaft 31.
A driven pulley 59 provided on an output shaft 58 supported between the rear portion of the right casing 37

and the reducer casing 39 includes a fixed pulley half 60 relatively rotatably supported by the output shaft 58, and a movable pulley half 61 moved close to or apart from the fixed pulley half 60. The movable pulley half 61 is biased toward the fixed pulley half 60 by means of a spring 62. A starting clutch 63 is provided between the fixed pulley half 60 and the output shaft 58. An endless V-belt 64 is wound around the drive pulley 54 and the driven pulley 59.
An intermediate shaft 65 and an axle 66 in parallel to the output shaft 58 are supported between the right casing 37 and the reducer casing 39. A reduction gear train 67 is provided between the output shaft 58, intermediate shaft 65 and axle 66. A rear wheel WR is provided on the right end, passing through the reducer casing 39 and projecting rightwardly therefrom, of the axle 66.

In such a continuously variable transmission M, the rotational power of the crank shaft 31 is transmitted to the drive pulley 54, and is then transmitted from the drive pulley 54 to the rear wheel WR via the V-belt 64, driven pulley 59, starting clutch 63, and reduction gear

train 67 .
Upon rotation of the engine E at a low speed, since the centrifugal force applied to the centrifugal weight 57 of the drive pulley 54 is small, the width of the groove between the fixed pulley half 60 and movable pulley half 61 is reduced by the biasing force of the spring 62 of the driven pulley 59, with a result that a speed varying ratio becomes the "LOW" speed mode. As the rotational speed of the crank shaft 31 is increased in such a "LOW" speed mode, the centrifugal force applied to the centrifugal weight 57 is increased and thereby the width of the groove between the fixed pulley half 55 and the movable pulley half 56 of the drive pulley 54 is reduced and correspondingly the width of the groove between the fixed pulley half 60 and the movable pulley half 61 of the driven pulley 59 is increased, with a result that the speed varying ratio is continuously varied from the "Low" speed mode to a "TOP" speed mode.
An AC generator 68 provided on the right side of the crank shaft 31 is covered with the generator cover 36, and a radiator 69 is provided on the right side of the generator cover 36. A cooling fan 70 for supplying


cooling wind to the radiator 69 is fixed to the right end of the crank shaft 31 in such a manner as to be disposed between the AC generator 68 and the radiator 69. The cooling fan 70 and the radiator 69 disposed outside the cooling fan 70 are covered with a synthetic resin made cover 74 fastened to the generator cover 36. A louver 75 for sucking cooling air from the outside is provided on the outer side surface of the cover 74.
A thermostat case 72 which contains a thermostat 71 is connected to the right side surface of the cylinder head 34. A cooling water pump 73 provided on the right end of the cam shaft 44 is contained in a space surrounded by the cylinder head 34 and the thermostat case 72.
Referring again to Figs. 1 and 2, a rear cushion unit 76 is provided between a rear portion of the power unit P and the rear frame 12. An exhaust pipe 77 for discharging exhaust gas from the engine E projects from the engine E and extends along the right side of the rear wheel WR. The exhaust pipe 77 is connected to an exhaust muffler 78 disposed on the right side of the rear wheel WR. A stand 79 is turnably supported by the engine E.

A luggage box 80 for containing a helmet or the like is supported on the upper surface of an intermediate portion of the rear frame 12 in such a manner as to be located over the engine E. A fuel tank 81 is supported or the sub-frame 13. [O029],
Referring to Figs. 5 and 6, an air cleaner 82 for cleaning air to be fed to an intake system of the engine E is mounted on the rear portion of the power unit P in such a manner as to be located on the side of an upper portion of the rear wheel WR. A secondary air cleaner 83 for cleaning air to be fed to an exhaust system of the engine E is additionally provided on a front portion of the air cleaner 82. [0030]
The air cleaner 82 and the secondary air cleaner 83 include a common cleaner case 84 . The cleaner case 84 is formed by connecting synthetic resin made first and second case members 85 and 86 to each other. The first case member 85 integrally includes a bowl-shaped large case portion 85a, and a bowl-shaped small case member 85b which is smaller than the large case portion 85a and is opened in the same direction as the opening direction of

the large case portion 85a. The second case member 86 integrally includes a bowl - shaped large case portion 86a, and a small case portion 86b formed into a cylindrical shape with a bottom. The small case portion 86b is to be fitted in the small case portion 85b of the first case member 85. The large case portions 85a and 86a of the first and second case members 85 and 86 are fastened to each other by means of a plurality of screw members 87.
The air cleaner 82 is configured such that the peripheral edge portion of a retaining member 89 for retaining a cleaner element 88 is held between the large case portion 85a of the first case member 85 and the large case portion 86a of the second case member 86. A first non-cleaning chamber 91 is formed between the cleaner element 88 retained by the retaining member 89 and the large case portion 85a of the first case member 85. A first cleaning chamber 92 is formed between the cleaner element 88 retained by the retaining member 89 and the large case portion 86a of the second case member 86 .
Referring to Fig. 7, an inlet duct 93 for introducing air from the outside to the first non-



cleaning chamber 91 is provided in a rear lower portion of the air cleaner 82. The inlet duct 93 includes a small-diameter pipe 94 and a large-diameter pipe 95. The small-diameter pipe 94 is disposed in the first non-cleaning chamber 91 while being tilted rearwardly, upwardly. The lower end of the small - diameter pipe 94 is supported by the large case portion 85a of the first case member 85. The large - diameter pipe 95, having a diameter larger than that of the small - diameter pipe 94, is integrated with the large case portion 85a. The lower end of the small-diameter pipe 94 is opened to the upper end of the large - diameter pipe 95, and the lower end of the large-diameter pipe 95 is opened downwardly at a position behind the power unit P. [0 03 3']
A notch 96 is provided in a rear lower portion of the large-diameter pipe 95. As shown in Fig. 5, a distance LI between the upper end of the notch 96, that is, the opening end of a rear portion of the large-diameter pipe 94 and the opening end of a lower portion of the small-diameter pipe 94 is set to be shorter than a distance L2 between the opening end of the lower portion, excluding the rear portion (that is, the notch 96), of the large-diameter pipe 94 and the opening end of the

lower portion of the small - diameter pipe 94.
One end of a synthetic resin made first intake pipe 98 is connected to the large case portion 86a of the second case member 86 in such a manner as to be communicated to the first cleaning chamber 92, and a resonator 99 is connected to an intermediate portion of the first intake pipe 98. The other end of the first intake pipe 98 is connected to a carburetor 100 disposed in front of the air cleaner 82 and between the engine E and the luggage box 80. One end of a second intake pipe 101 is connected to the carburetor 100, and the other end of the second intake pipe 101 is connected to an intake port of the cylinder head 34. In this way, air introduced from the inlet duct 93 into the first non-cleaning chamber 91 of the air cleaner 82 is cleaned while flowing into the first cleaning chamber 92 through the cleaner element 88, and is introduced to the carburetor 100. Then, a mixture generated in the carburetor 100 is sucked in the intake port.
A negative pressure extraction pipe 102 communicated to the first cleaning chamber 92 is provided in the large case portion 86a of the second case member

86. The negative pressure extraction pipe 102 is connected to the carburetor 100 via a negative pressure duct 103.
A connection pipe 105 to be connected to a duct 104 for introducing a blow-by gas from the engine E is provided in the large case portion 86a of the second case member 86 in such a manner as to be communicated to the first cleaning chamber 92 at a position near the opening end of the first intake pipe 98. To prevent the cleaner element 88 from being brought into direct-contact with the blow-by gas introduced from the connection pipe 105 into the first cleaning chamber 92 and thereby contaminated therewith, a baffle 106 is disposed in the large case portion 86a in such a manner as to be fixedly interposed between the inner end opening portion of the connection pipe 105 and the cleaner element 88.
The secondary air cleaner 83 includes the small case portion 85b, the small case portion 86b of the second case member 86, and a cleaner element 109 disposed between the small case portions 85b and 86b while being held between a plurality of projections 107 and 108 respectively provided on the small case portions 85b and

86b. A second non-cleaning chamber 110 smaller in capacity than the first non-cleaning chamber 91 is formed between the cleaner element 109 and the small case portion 85b of the first case member 85. A second cleaning chamber 111 smaller in capacity than the first cleaning chamber 92 is formed between the cleaner element 109 and the small case portion 86b of the second case member 86. The small case portions 85b and 86b are connected to each other by means of a screw member 112.
A connection pipe 113 communicated to the second cleaning chamber 111 is integrally provided in the small case portion 86b of the second case member 86. One end of a first air duct 114 is connected to the connection pipe 113, and the other end of the first air duct 114 is connected to an air flow control valve 115. As shown in Fig. 3, the air flow control valve 115 is mounted to the head cover 35 at a position opposed to the position of an ignition plug 116 mounted in the cylinder head 34. The air flow control valve 115 is also connected to a check valve 117 typically configured as a reed valve provided in the head cover 35 via a second air duct 118. Secondary air cleaned by the secondary air cleaner 83 is controlled in its amount by the air flow control valve 115, and is

fed to the exhaust port (not shown) of the cylinder head 34 via the check valve 117.
The air flow control valve 115 is operated in response to an intake negative pressure of the engine E, and a negative pressure duct 119 for introducing a negative pressure to the air flow control valve 115 is connected to an intermediate portion of the second intake pipe 101. IH) 0 4 0 J
An air introduction pipe 120 for introducing air from the outside into the second non-cleaning chamber 111 of the secondary air cleaner 83 is provided integrally with the small case portion 86b of the second case member 86 in such a manner as to pass through the cleaner • element 109 with its inner end opened in the second non-cleaning chamber 111. An inlet tube 121 with its one end connected to the air introduction pipe 120 extends forwardly of the vehicular body by way of the vicinity of a shaft 131 for swingably supporting the engine E on the body frame F.
The engine E is supported on the rear frame 12 of the body frame F via the vibration-proof link 22. The


structure of such a vibration-proof link 22 will be
described with reference to Figs. 8 and 9.

The vibration-proof link 22 includes a pair of left and right engine side brackets 1231 and 1232 provided on the engine E; a pair of left and right links 1241 and 1242 having lower ends swingably connected to the engine side brackets 123x and 1232 and the upper ends swingably connected to the rear frame 12; a cross-member 125 for connecting the links 1241 and 1242 to each other; and a pair of stopper rubbers 126 and 127 provided on one link 124 in such a manner as to be in contact with the rear frame 12.
The engine side brackets 1231 and 1232 projecting upwardly from the engine E have two mounting holes 128 coaxial with each other. Two rubber bushes 129 are press-fitted in the mounting holes 128. A cylindrical spacer 130 is inserted in both the rubber bushes 129. Both ends of a bolt as the swingably supporting shaft 131 inserted in both the rubber bushes 129 and the spacer 130 are connected to the engine side brackets 1231 and 1232
Both sides of the rear frame 12 has two supporting


holes 132 coaxial with each other. Two rubber bushes 133 are press-fitted in the supporting holes 132. Two bolts 134 provided at the other ends of the links 124x and 1242 in such a manner as to be in parallel to the swingably supporting shaft 131 are swingably supported by both the sides of the rear frame 12 via the rubber bushes 133. [0 0 45]
A box-shaped rubber supporting portion 135 is provided on one link 124t in such a manner as to be offset forwardly from a straight line connecting the centers of the swingably supporting shaft 131 and the bolt 134 to each other. The bottom surface of the rear frame 12 has a contact surface 136 to be brought into contact with the stopper rubber 126 mounted on the rubber supporting portion 135. A box-shaped rubber supporting portion 137 is provided on the one link 1241 in such a manner as to be offset rearwardly from the straight line connecting the centers of the swingably supporting shaft 131 and the bolt 134 to each other. The bottom surface of the rear frame 12 has a contact surface 138 to be brought into contact with the stopper rubber 127 mounted on the rubber supporting portion 137 .
The cross-member 125 for connecting the links 1241

and 1242 to each other is formed into an approximately U-shape opened downwardly. The cross-member 125 is disposed astride the second intake pipe 101 for connecting the engine E to the carburetor 100 disposed behind the links 1241 and 1242.
In such a vibration-proof link 22, a load applied from the engine E of the power unit P to the swingably supporting shaft 131 is absorbed by elastic deformation of the rubber bushes 129, elastic deformation of the stopper rubber 126 and 127 pressed to the contact surface 136 and 138, and elastic deformation of the rubber bushes 133 .
The inlet tube 121 extends forwardly of the vehicular body by way of the vicinity of the swingably supporting shaft 131 of the vibration-proof link 22.
The body frame F is covered with a synthetic resin made body cover 141. The body cover 141 includes a leg shield 141a for covering the front side of driver's legs; a step floor 141b connected to a lower portion of the lee shield 141a for allowing driver's feet to be rested thereon; an under cover 141c, connected to the leg shielc


141a and step floor 141b, for covering the lower side of the step floor 141b; and a side cover 141d, connected to the step floor 141b and under cover 141c, for covering both sides of the rear portion of the vehicular body.
Most of the luggage box 80 supported on the rear frame 12 and the fuel tank 81 supported on the sub-frame 13 are covered with the side cover 141d. A seat 142 capable of covering the luggage box 80 is openably/closably mounted on the upper portion of the side cover 141d in such a manner as to be located over the engine E. An oiling cap 81a of the fuel tank 81 projects upwardly from the upper portion of the side cover 141d.
Referring particularly to Fig. 3, a box-shaped compartment 143 opened upwardly is fixedly disposed under the step floor 141b at a position between both the floor supporting frames 16 of the front frame 11. A battery 145 is contained in a front portion of the compartment 143 in a state being fixed by means of a rubber band 144 . The compartment 143 also contains relays 146, 147 and 148 disposed on the left side of the battery 145, fuses 149 and 150 disposed on the back side of the battery 145, a


regulator 151 disposed on the back side of the fuses 149 and 150, and a radiator reserve tank 147 disposed on the back side of the battery 145 and on the right side of the regulator 151.
The inlet tube 121 extends forwardly from the secondary air cleaner 83 with its one end connected to the secondary air cleaner 83. The other end of the inlet tube 121 extends to the lower side of the step floor 141b, and is opened in the compartment 143.
As shown in Fig. 2, in the motorcycle according to this embodiment, the radiator 69 is disposed on the right side of the engine E. To guard the radiator 69 when such a motorcycle is tilted on the right side for maintenance or the like, the radiator 69 and the cover 74 for covering the radiator 69 are disposed inwardly from the right side outer surface of the under cover 141c.
A plurality (for example, three) of reinforcing ribs 154 are integrally provided on the inner surface of the right side rear portion of the under cover 141c in such a manner as to be able to be brought into contact with the right side surface of the rear frame 12 of the

body frame F. The projecting amount of each reinforcing rib 154 on the rear frame 12 side is set such that in the usual state of the motorcycle, the reinforcing rib 154 is not required to be brought into contact with the right side surface of the rear frame 12; but in the tilting state of the motorcycle on the right side, the reinforcing rib 154 is brought into contact with the right side surface of the rear frame 12 by deflection of the under cover 141c due to contact of the outer right surface of the under cover 141c with the ground, and thereby the cover 74 is not brought into contact with the ground.
The function of this embodiment will be described below. Since the secondary air cleaner 83 for cleaning secondary air to be fed to the exhaust system of the engine E (exhaust port of the cylinder head 34 in this embodiment) is mounted on the power unit P, it is possible to connect the secondary air cleaner 83 to the exhaust system of the engine E before the assembly of the power unit P to the body frame F, and hence to facilitate the connection work for the secondary air cleaner 83.
The capacity of the secondary air cleaner 83 must

be minimized because the secondary air cleaner 83 is mounted to the power unit P; however, since the inlet tube 121 for introducing air from the outside into the secondary air cleaner 83 extends from the secondary air cleaner 83, it is possible to increase the substantial capacity of the secondary air cleaner 83 by the inlet tube 121, and hence to reduce the suction sound of air.
Since the inlet tube 121 extends up to the step floor 141b by way of the vicinity of the shaft 131 for swingably supporting the engine E to the body frame F, the inlet tube 121 can be suitably laid out at a position less affected by water or mud splashed by the rear wheel WR while being prevented from being applied with an external bending force or the like caused by swing motion of the power unit P as much as possible. [0050]
The compartment 143 opened upwardly, which contains the electric equipment such as the battery 145, relays 146, 147 and 148, fuses 149 and 150, and regulator 151, and also contains the radiator reserve tank 147, is disposed under the step floor 141b, and the inlet tube 121 is opened in the compartment 143. Accordingly, it is possible to more effectively prevent occurrence of


suction sound of air in the secondary air cleaner 83, and to more effectively prevent the secondary air cleaner 83 from being affected by water or mud.
In this motorcycle, the radiator 69 and the cover 74 for covering the radiator 69 are disposed on the right side of the engine E. To be more specific, the reinforcing ribs 154, which can be brought into contact with the rear frame 12 of the body frame F, project from the inner surface of the under cover 141c on the side on which the radiator 69 is disposed, that is, on the right side inner surface of the under cover 141c, and the radiator 69 and the cover 74 are disposed inwardly from the right side outer surface of the under cover 141c.
Accordingly, when the motorcycle is tilted for maintenance or the like, the right side outer surface of the under cover 141c is brought into contact with the ground earlier than the radiator 69 and cover 74, so that the rigidity of the right side of the under cover 141c can be ensured by contact of the reinforcing ribs 154 with the rear frame 12. Accordingly, it is possible to prevent the radiator 69 and cover 74 from being brought into contact with the ground.

As a result, it is possible to eliminate the need of using part of the body frame F as the guard for the radiator 69 and the cover 74, and hence to reduce the cost by avoiding an increase in weight of the body frame F. Also, since the width of the body frame F is not extended, it is possible to prevent the lowering of the resting characteristic of the driver's feet. Further, since the body frame F can be applied to another kind of the motorcycle only by modifying part of under cover 141c it is possible to enhance the general-purpose properties,
The inlet duct 93 for introducing air from the outside into the air cleaner 82 whose cleaner case 84 is mounted to the power unit P includes the small-diameter pipe 94 having the upper end communicated to the first non-cleaning chamber 91 in the cleaner case 84 and the large-diameter pipe 95 having the diameter larger than that of the small-diameter pipe 94 and having the upper end communicated to the lower end of the small - diameter pipe 94. The distance L1 between the opening end of the rear portion of the large-diameter pipe 94 and the opening end of the lower portion of the small - diameter pipe 94 is set to be shorter than the distance L2 between

the opening end of the lower portion, excluding the above rear portion, of the large-diameter pipe 94 and the opening end of the lower portion of the small - diameter pipe 94.
With this inlet duct 93, it is possible to generate a negative pressure at a position behind the front wall of the large-diameter pipe 95 of the inlet duct 93 upon running of the motorcycle, and hence to effectively introduce outside air into the first non-cleaning chamber 91 via the inlet duct 93 by making use of the negative pressure. In other words, the suction direction of the outside air into the inlet duct 93 can be specified onto the rear side of the inlet duct 93. Accordingly, even if dust is deposited on the rear portion of the power unit P by suction of wind due to the negative pressure caused on the rear side of the body cover 141 upon running of the motorcycle, it is possible to avoid the suction of dust into the air cleaner 82 as much as possible. Further, the feature of generating the negative pressure on the rear side of the large-diameter pipe 95 of the inlet duct 93 can be simply obtained only by providing the notch 96 in part of the large - diameter pipe 95, that is, without increasing the manufacturing cost.


While the embodiment of the present invention has been described in detail, the present invention is not limited thereto, and it is to be understood that many changes in design may be made without departing from the scope of the claims.
[Effect of the Invention]
As described above, according to the invention described in claim 1, since the secondary air cleaner is connected to the exhaust system of the engine before being assembled to the body frame, it is possible to facilitate the connection work of the secondary air cleaner to the exhaust system. Also, it is possible to increase the substantial capacity of the secondary cir cleaner by provision of the inlet tube, and further, it is possible to prevent the secondary air cleaner from being affected by water and mud by extending the inlet tube up to a suitable position.
According to the invention described in claim 2, in addition to the configuration of the invention described in claim 1, it is possible to suitably lay out the inlet tube while preventing the inlet tube from being applied

with an external bending force or the like caused by swing motion of the power unit as much as possible. [M£3r]
According to the invention described in claim 3, is possible to more effectively reduce occurrence of suction sound, and to more effectively prevent the secondary air cleaner from being effected by water and mud.
[Explanation of Characters] 83: secondary air cleaner, 117: check valve, 121: inlet tube, 131: swingably supporting shaft, 141: body cover, 141b: step floor, 143: compartment, E: engine, F: body frame, M: continuously variable transmission, P: power unit


We claim:
1. An exhaust emission control system for a motorcycle comprising an exhaust system of an engine (E) which constitutes a power unit (P) in co-operation with a continuously variable transmission (M) and is swingably supported by a body frame (F), and a secondary air cleaner (83) for cleaning secondary air to be fed to said exhaust system, wherein said secondary air cleaner (83) is connected to said exhaust system via a check valve (117) characterized in that an inlet tube (121) with its one end connected to said secondary air cleaner (83) mounted on said power unit (P) extends from said secondary air cleaner (83).
2. An exhaust emission control system for a motorcycle as claimed in claim 1, wherein said inlet tube (121) extends up to the lower side of a step floor (141b) of a body cover (141) for covering said body frame (F) by way of the vicinity of a shaft (131) for swingably supporting said engine (E) on said body frame (F).
3. An exhaust emission control system for a motorcycle as claimed in claim 2, wherein a box-like compartment (143) opened upwardly is disposed under said step floor (141b), and the other end of said inlet tube (121) is opened in said compartment (143).


4. An exhaust emission Control system for a motorcycle substantially
as hereinbefore described with reference to the accompanying drawings.
Dated this 9th day of May, 2000.
[RANJNA MEHTA DUTT]
OF REMFRY AND SAGAR
ATTORNEY FOR THE APPLICANTS



Documents:

429-mum-2000-cancelled(pages)-(15-6-2005).pdf

429-mum-2000-claims granted-(15-6-2005).pdf

429-mum-2000-claims(granted)-(15-6-2005).doc

429-mum-2000-correspondence(6-9-2000).pdf

429-mum-2000-correspondence(ipo)-(13-2-2007).pdf

429-mum-2000-drawing(15-6-2005).pdf

429-mum-2000-form 1(14-12-2007).pdf

429-mum-2000-form 1(9-5-2000).pdf

429-mum-2000-form 13(14-12-2007).pdf

429-mum-2000-form 19(15-4-2004).pdf

429-mum-2000-form 2(granted)-(15-6-2005).doc

429-mum-2000-form 2(granted)-(15-6-2005).pdf

429-mum-2000-form 3(15-6-2005).pdf

429-mum-2000-form 3(28-2-2001).pdf

429-mum-2000-form 3(9-5-2000).pdf

429-mum-2000-form 5(9-5-2000).pdf

429-mum-2000-petition under rule 137(15-6-2005).pdf

429-mum-2000-petition under rule 138(15-6-2005).pdf

429-mum-2000-power of aouthrity(15-6-2005).pdf

429-mum-2000-power of aouthrity(6-9-2000).pdf

abstract1.jpg


Patent Number 207594
Indian Patent Application Number 429/MUM/2000
PG Journal Number 43/2008
Publication Date 24-Oct-2008
Grant Date 14-Jun-2007
Date of Filing 09-May-2000
Name of Patentee HONDA GIKEN KOGYO KABUSHIKI KAISHA
Applicant Address 1-1, MINAMIAOYAMA 2-CHOME, MINATO-KU, TOKYO,
Inventors:
# Inventor's Name Inventor's Address
1 TOSHIHIRO OOTAKA C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, 4-1 CHUO 1-CHOME, WAKO-SHI, SAITAMA,
2 KAZUNORI KAWAME C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, 4-1 CHUO 1-CHOME, WAKO-SHI, SAITAMA,
3 NORIHIKO SASAKI C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, 4-1 CHUO 1-CHOME, WAKO-SHI, SAITAMA,
PCT International Classification Number F01N 3/32
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 HEI-11-160148 1999-06-07 Japan