JP2002235535A - Exhaust emission control device for scooter type vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sub-air cleaner by suppressing an increase of the number of parts. SOLUTION: A rear wheel 21 is supported in a rear part of a swing type power unit 18 connected with a vehicle body frame so as to oscillate freely, and a rear fender 35 is arranged above the rear wheel 21 to support it on a rear frame 23. A case part of the sub-air cleaner 40 is integrally provided in a front part of the rear fender 35 and is connected with a secondary air control valve 42 supported on the rear frame 23 in front of it by a hose ignition coil 48, and the secondary air control valve 42 is connected with an exhaust passage of an engine 30 through a rubber hose 44 and a metallic pipe 45.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an exhaust gas purifying apparatus for a scooter type vehicle.

[0002]

2. Description of the Related Art It is not possible to provide a scooter type vehicle having a swing type power unit with an exhaust gas purifying apparatus for an engine having a secondary air control valve and a sub air cleaner for sending clean air to the secondary air control valve. As disclosed in Japanese Patent Application Laid-Open No. 6-50140, a secondary air control valve is attached to a muffler, and a sub air cleaner formed independently of other components is supported at the rear end of the muffler behind the secondary air control valve. A structure in which a hose is connected between the air control valve and the sub air cleaner is shown.

[0003]

By the way, when the sub air cleaner is provided independently as in the above-mentioned conventional example, the number of parts of the sub air cleaner itself increases, and a stay required for attaching the sub air cleaner to the vehicle body frame side. The number of parts and the number of mounting steps are increased by providing the above. In addition, it is desired to devise a layout in which the sub air cleaner is disposed with good space efficiency in consideration of the characteristics of the scooter type vehicle, and further, it is also desired to take measures to improve the durability of the sub air cleaner.

[0004]

According to a first aspect of the present invention, there is provided an exhaust gas purifying apparatus for a scooter type vehicle, wherein an engine and a transmission case are integrally formed, and a rear wheel is provided at a rear portion of the transmission case. A scooter-type vehicle configured to suspend a swing-type power unit supporting the vehicle body at a rear portion of the vehicle body and to purify exhaust gas by sending secondary air from a sub air cleaner to a exhaust passage of an engine via a secondary air control valve. A rear fender is arranged above the rear wheel to be supported by the vehicle body frame, and a case portion of the sub air cleaner is formed integrally with the rear fender.

According to a second aspect of the present invention, in the first aspect, an air intake air cleaner for the engine is disposed above the transmission case of the swing type power unit and on one side of the rear wheel, and the vehicle body sandwiches the air cleaner and the rear wheel. The sub air cleaner is disposed on the opposite side.

According to a third aspect of the present invention, in the first aspect, the intake port of the sub air cleaner is opened toward the rear of the vehicle body on the rear fender.

[0007]

According to the first aspect of the present invention, the case portion of the sub air cleaner is formed integrally with the rear fender.
Even if the sub air cleaner is provided, an increase in the number of parts can be suppressed only in the case portion. In addition, since it is not necessary to support the sub air cleaner alone on the vehicle body frame or the like, the number of mounting steps can be suppressed.

According to the second aspect of the present invention, since the air cleaner and the sub air cleaner are disposed on both sides of the vehicle body with the rear wheel interposed therebetween, the sub air cleaner can be disposed with good space efficiency by utilizing the characteristics of the scooter type vehicle.

According to the third aspect of the present invention, the intake port of the sub air cleaner is opened toward the rear of the vehicle body on the rear fender, so that the sub air cleaner is less susceptible to dust, water, and the like jumped up by the rear wheel on the rear fender. The air can be sucked, and the cleaning cycle of the air filter can be lengthened.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described below with reference to the drawings. FIG. 1 is a side view of a scooter type vehicle to which the present embodiment is applied, FIG. 2 is a diagram showing an internal structure of a rear part of a vehicle body of the scooter type vehicle, FIG. 3 is a plan view of the same portion, and FIG. FIG. 5 is a cross-sectional view (a cross-sectional view taken along line 4-4 in FIG. 3), and FIG.

First, the overall body will be outlined. 1 is a front wheel, 2 is a front fork, 3 is a front fender, 4 is a metal front cover, 5 is a metal or resin front back cover, 6 is a resin handle cover, 7 is a headlight, 8 is a handle.

A central portion of the vehicle body forms a low-floor step floor 10 as a footrest portion, and a rear portion of a hollow rear opening 11 which rises upward at a predetermined height and extends rearward at a predetermined height. Is provided. The rear cover 11 is made of metal or resin, and its upper opening is opened and closed by a seat 12 that is long in the front-rear direction. A storage box 13 opened upward is provided in the rear cover 11, and the inside has a large capacity capable of storing a large article such as a helmet.

Below the step floor 10, there is provided a main frame 14 made of a metal pipe extending in the front-rear direction along the center of the vehicle body and a cross pipe 15 extending rearward in the left-right direction. Is connected to an arm 19 extending forward from a lower portion of the swing type power unit 18 via a link 17 having one end pivotally supported by a link support portion 16 protruding rearward.
The swing-type power unit 18 can swing up and down around the swing centers 20 and 20b.

A rear wheel 21 is supported on one side of the rear end of the swing type power unit 18, and a rear cushion unit 22 is connected to a rear frame 23, whereby the swing type power unit 18 is moved to the rear of the body frame. Suspended.

The rear frame 23 has a substantially U-shape in a plan view, and is provided in a pair of right and left parts from the front end to the rear part in a substantially parallel manner in a front-rear direction. It is connected to the pipe 15. The main frame 14, the cross pipe 15, and the rear frame 23 are integrated to form a body frame.

As shown in FIG. 2, a spare tire mounting pipe 24 projects upward from the rear end of the rear frame 23 and extends outward from the rear surface of the rear cover 11, where the spare tire 25 (FIG. 1) is supported.

The swing type power unit 18 includes a front four-cycle air-cooled engine 30 and a rear transmission case 31.
The engine 30 is inclined forward in a substantially horizontal direction, the swing type power unit 18 is formed to be long in the front-rear direction as a whole, and the rear wheel 2 is provided at one rear end of the transmission case 31.
1 is supported.

On the transmission case 31, an air cleaner 32 for intake of the engine 30 and serving as a main for a sub air cleaner described later is supported. At the front end of the air cleaner 32, a breather tank 33 is provided.
Here, a breather tube 34 is connected from the upper part of the cylinder head of the engine 30 to collect unburned gas of the engine 30 into a breather tank.
To return to

A rear fender 35 made of resin is disposed above the rear wheel 21 and is supported by the rear frame 23. The support portion is provided on the front and rear portions of the rear fender 35, and the front portion is integrally formed and connects the mounting portion 35 projecting upward to the stay 27 projecting downward from the cross pipe 26 of the rear frame 23, and the rear portion is integrally formed. The mounting portion 37 protruding upward is mounted on the stay 28 protruding downward from the rear end of the rear frame 23 with a bolt 38 and a nut 39.

As shown in FIG. 3, a sub air cleaner 40 is integrally provided at the front end of the rear fender 35 on the right side of the vehicle body opposite to the air cleaner 32 with the rear wheel 21 interposed therebetween. A rubber hose 41 extends forward from the bottom of the sub air cleaner 40 and is connected to a secondary air control valve 42 for exhaust purification disposed forward of the sub air cleaner 40.

The secondary air control valve 42 has a built-in air cut valve for controlling the amount of air supplied and a reed valve which is a check valve for exhaust backflow. The reed valve prevents exhaust gas from the exhaust passage from flowing back to the air cut valve and the sub air cleaner. The air cut valve is connected to the intake side of the engine by a negative pressure pipe 43, and shuts off the supply of secondary air to the exhaust passage at the time of engine deceleration to prevent afterburn in the muffler.

The secondary air control valve 42 and the engine 30 are connected by a rubber hose 44 and a metal pipe 45. The rubber hose 44 curves convexly forward in the plan view of FIG. 3 and crosses over the engine 30 in the left-right direction. And is connected from the front of the secondary air control valve 42 to a joint 42a (FIG. 3) provided on the front surface thereof. The joint 42a of the secondary air control valve 42
A rubber hose 44 projecting forward from the front surface of the next air control valve 42 integrally with the swing type power unit 18.
(The direction indicated by the arrow A in FIG. 2).

The other end extends to the left side of the engine 30 and is bent obliquely backward and diagonally downward to the left side of the engine 30 to be connected to one end of a metal pipe 45 by a joint 45a, as is apparent in FIG. (Fig. 3). The direction of the joint 45a is the swing direction at the upper end of the metal pipe 45 that swings together with the swing type power unit 18 (the direction indicated by the arrow B in FIG. 2).
And the direction is almost the same.

The metal pipe 45 extends in the vertical direction on the left side of the engine 30, and the other end goes under the engine 30 and connects to the exhaust passage of the engine 30. One end of an exhaust pipe 46 is connected to the exhaust passage of the engine 30. The exhaust pipe 46 extends from under the engine 30 to the right side of the vehicle body, and is connected to a muffler 47 disposed on the right side of the rear wheel 21. The muffler 47 is located below the sub air cleaner 40.

The secondary air control valve 42 is mounted on a valve stay 29 projecting downward from the rear frame 23 on the right side of the vehicle body. Further, an ignition coil 48 is supported at a portion continuous to the valve stay 29, and a high tension cord 49 extends forward from the ignition coil 48 and is connected to a spark plug of the four-cycle air-cooled engine 30.

As shown in FIG. 4, the sub air cleaner 40
The case 50 is formed integrally with the rear fender 35, and a joint pipe 51 projecting downward is integrally formed at the bottom front end, and one end of a hose 41 is connected thereto from below.

The case 50 is opened upward, an air filter 52 is accommodated in the opening, a lid 53 is covered from above, and the lid 53 is integrated with the case 50 by bolts 54 inserted from below. You. The inside of the sub air cleaner 40 is partitioned by an air filter 52 into a lower clean room 55 and an upper dirty room 56.

An intake duct 57 formed integrally with the lid 53 is connected to the dirty room 56. The intake duct 57 extends horizontally rearward from the center of the lid 53, projects rearward from the rear surface of the lid 53, opens rearward above the rear fender 35, and opens rearward.
The upper air is sucked from behind. The air that has entered the dirty room 56 from the intake duct 57 is purified when entering the clean room 55 through the air filter 52, becomes purified air, and is sent to the secondary air control valve 42.

Reference numeral 60 in FIG. 3 denotes a connecting tube, and 61 denotes a vaporizer. The connecting tube 60 has a rear end connected to the front of the air cleaner 32 to communicate with the clean room, and a front end connected to the vaporizer 6.
Connect to 1. A breather tank 33 is located in the middle.
Are connected to each other to return the breather gas to the vaporizer 61. The carburetor 61 is connected to an intake passage of the engine 30.

Further, as shown in FIG.
The front side can be turned upward around a pivot 23a provided at the rear end of the rear frame 23 together with the seat 12, and this turning state can be held by the stay 63, and is disposed inside the rear cover 11. Maintenance of a swing-type power unit-related portion described later can be performed. Further, reference numeral 64 shown in FIG. 2 denotes a fuel tank, which is disposed above the rear fender 35 and supported by a rear portion of the rear frame 23. When the stay 63 is in the stored state,
The front end is supported by the frame and the rear end is supported by the rear fender.

Next, the operation of this embodiment will be described. As is clear from FIGS. 3 and 4, the case 50 of the sub air cleaner 40 is formed integrally with the rear fender 35, so that the sub air cleaner 40 does not have to be provided alone, and an increase in the number of parts can be suppressed. Moreover, the sub air cleaner 40 is not attached to the rear frame 23, and the rear fender 3
Since it is only necessary to mount 5 on the rear frame 23, a special mounting member for a sub air cleaner such as a stay is not required, the number of parts can be reduced, and an increase in the number of mounting steps can be suppressed.

Further, since the sub air cleaner 40 and the air cleaner 32 are separately disposed on both the left and right sides of the vehicle body with the rear wheel 21 interposed therebetween, there is relatively room for the article disposition space on the right side of the rear cushion unit 22 and above the muffler 47. By utilizing the characteristics of a certain scooter-type vehicle, the sub-air cleaner 40 can be arranged efficiently.

Further, as is apparent from FIG. 4, the sub air cleaner 40 provided at the front right end of the rear fender 35 near the inner surface of the right side wall of the rear cover 11 moves the intake duct 57 rearward above the rear fender 35. Since it is open, the rear cover 11 and the rear fender 35
Suction air from the space surrounded by. For this reason, the rear wheel 2
Since relatively small air that is hard to enter the dust or water that jumps up can be sucked, clogging of the air filter 52 is less likely to occur, and the cleaning cycle of the air filter 52 can be lengthened.

As shown in FIGS. 2 and 3, a metal pipe 45 swinging integrally with the swing type power unit 18 is provided.
And a secondary air control valve 42 fixed to the rear frame 23 side
And a rubber hose 44, and the rubber hose 44 is disposed so as to traverse the upper part of the engine 30 in the left-right direction while bending the rubber hose 44 to protrude forward in a plan view. Metal pipe 45
Change the distance between the upper end and the secondary air control valve
4 can be easily absorbed by deformation of the long curved portion.

Further, as is apparent from FIG. 2, the rubber hose 44 is formed into a right-angled shape in a side view, and the secondary air control valve 4 is formed.
On the second side, the direction in which the right side portion of the rubber hose 44 moves (the direction indicated by the arrow A) in accordance with the swing of the swing type power unit 18 and the direction in which the joint 42a protrudes are made substantially coincident with each other. And it is hard to fall out.

Also, on the metal pipe 45 side, by making the direction of the joint 45a substantially coincide with the swinging direction (the direction of arrow B), the torsion applied to the connecting portion is also reduced, and it is difficult to come off. Therefore, the twisting that occurs at the connection portion of the secondary air pipe of the exhaust gas purifying device, which is an inherent phenomenon associated with the use of the swing type power unit 18, can be reduced to make it difficult to come off, and the connection structure has high reliability. become.

In addition, since the secondary air control valve 42 is fixed to the rear frame 23, the swinging portion has the swing center 20a,
0b, and as a result, the amount of swing becomes small, so that piping becomes easy. However, the secondary air control valve 42 can be arbitrarily provided on the side of the swing type power unit 18 such as the muffler 47 as in the conventional example. The rubber hose 44 may be arbitrarily changed to an elastic tube such as a metal flexible or elastic resin hose or tube.

[Brief description of the drawings]

FIG. 1 is a side view of a scooter type vehicle to which an embodiment is applied.

FIG. 2 is a side view showing an internal structure of a rear portion of the main body of the scooter type vehicle.

FIG. 3 is a plan view of the same part.

FIG. 4 is a sectional view of a sub air cleaner portion (4-4 in FIG. 3);
Line cross section)

FIG. 5 is a view for explaining the operation of the rear part of the scooter type vehicle in FIG. 1;

[Description of Signs] 11: Rear cover, 12: Seat, 14: Main frame, 15: Cross pipe, 17: Link, 18: Swing type power unit, 20: Swing center, 21: Rear wheel, 2
3: rear frame, 30: engine, 31: transmission case, 32: air cleaner, 33: breather tank, 3
5: Rear fender, 40: Sub air cleaner, 42: 2
Secondary air control valve, 44: rubber hose, 45: metal pipe,
46: exhaust pipe, 50: case part, 52: air filter,
53: lid, 57: intake duct

Claims (3)

[Claims] 1. An engine and a transmission case are integrally formed,
A swing type power unit supporting the rear wheels is suspended from the rear of the vehicle body at the rear of the transmission case, and secondary air is sent from the sub air cleaner to the exhaust passage of the engine via a secondary air control valve to purify exhaust gas. In the scooter-type vehicle having the above structure, a rear fender is disposed above the rear wheel and supported by a vehicle body frame, and a case portion of the sub air cleaner is formed integrally with the rear fender. apparatus. 2. An intake air cleaner for an engine is disposed above a transmission case of the swing type power unit and on one side of a rear wheel, and the sub air cleaner is disposed on a side opposite to the vehicle body with the air cleaner and the rear wheel interposed therebetween. The exhaust gas purifying apparatus for a scooter type vehicle according to claim 1, wherein: 3. The exhaust gas purifying apparatus for a scooter type vehicle according to claim 1, wherein an intake port of the sub air cleaner is opened on the rear fender toward a rear side of the vehicle body.