JP3586284B2 - Scooter exhaust gas purification device - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to an exhaust gas purifying apparatus for a scooter that introduces secondary air into exhaust gas to completely burn unburned components, and particularly relates to an arrangement position of an air cleaner, a check valve, and a secondary air introduction pipe. is there.
[0002]
[Prior art]
A secondary air introduction type exhaust gas purifier that introduces secondary air from the outside into the exhaust muffler and completely burns harmful unburned components contained in the exhaust gas is commonly used in vehicles such as motorcycles. It is used for This exhaust gas purification device is configured by connecting a secondary air introduction pipe near the base end of an exhaust muffler, and providing a check valve at the other end of the secondary air introduction pipe.
[0003]
In the exhaust muffler, a positive pressure and a negative pressure due to the pulsation of the exhaust gas are repeatedly generated, so that when the pressure in the exhaust muffler becomes a negative pressure, the check valve opens and the secondary air is introduced into the exhaust muffler. In addition, the oxygen in the secondary air reignites the unburned components in the high-temperature exhaust gas to complete the combustion. When the pressure inside the exhaust muffler becomes positive, the check valve closes to prevent the exhaust gas from flowing out.
[0004]
[Problems to be solved by the invention]
By the way, many scooters in recent years are provided with a large-capacity storage room capable of storing a helmet below a seating seat. In such a scooter, it is necessary to prevent an engine cylinder from interfering with the bottom of the helmet storage room. To avoid this, the cylinder is installed almost horizontally forward. The exhaust muffler attached to the cylinder extends downward (road surface side) of the cylinder and has a shape that curves backward.
[0005]
When installing the above-mentioned secondary air introduction type exhaust gas purifying device on such a scooter, a branch pipe is generally provided near the base end of the exhaust muffler, and a secondary pipe made of a heat-resistant rubber hose or the like is provided on the branch pipe. An air introduction pipe is connected, and a check valve is provided at the other end of the secondary air introduction pipe. The check valve is arranged at an upper part of the engine or the like.
[0006]
However, as described above, the exhaust muffler extends from the lower surface of the cylinder to the road surface side, and the clearance between the vicinity of the base end of the exhaust muffler and the road surface is small. An obstacle on the road surface or a flying stone jumped up by the front wheel could easily hit the secondary air introduction pipe connected near the portion, and the secondary air introduction pipe might be damaged.
[0007]
A small air cleaner is connected upstream of the check valve of the secondary air introduction pipe, but this air cleaner is placed as high as possible from the road surface to prevent dust and moisture from entering the secondary air. Must. Therefore, it is desirable that the air cleaner be disposed near the lower part of the seat. However, since the storage chamber is provided below the seat, the capacity of the storage chamber tends to be sacrificed by the installation of the air cleaner.
[0008]
Furthermore, in order to dispose the air cleaner above, it is necessary to fix the air cleaner to the body frame or the like, but this causes a change in the relative position between the power unit and the air cleaner that swings violently with respect to the body frame. There is a concern that the air inlet pipe will come off.
[0009]
The present invention has been made to solve such a problem, and even when the clearance between the vicinity of the base end of the exhaust muffler to which the secondary air introduction pipe is connected and the road surface is small, the secondary air introduction pipe is not required. The breaker can be effectively avoided, and the air cleaner for secondary air purification can be installed at a high position without sacrificing the capacity of the storage room provided below the seat and without causing the secondary air introduction pipe to come off. It is an object of the present invention to provide a scooter exhaust gas purifying apparatus capable of preventing dust and moisture from being mixed into secondary air.
[0010]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, a scooter exhaust gas purifying apparatus according to the present invention is configured such that a vehicle body frame 2 includes a head pipe 5 and a down tube 6 extending rearward and downward from the head pipe 5 as described in claim 1. And a pair of left and right rear frames 7 extending upward and rearward from the down tube 6, and provided with a storage chamber 9 in which a helmet 8 can be stored below the seating seat 10. Is supported by a pivot shaft 21 provided on the body frame 2 via suspension members 18 and 19, and the power unit 13 and the rear wheel 16 swing up and down around the pivot shaft 21. It is buffered by the buffer device 22 while being freely, secondary air to the exhaust gas flow path of the power unit 13 is supplied with air from the outside Introduction pipe 28, 31 is provided, constructed from the secondary air introducing pipe 28, 31 so as to re-combust the unburned components by introducing air in the exhaust gas in the exhaust gas flow path of the power unit 13 scooter In the exhaust gas purifying apparatus, the exhaust gas purifying apparatus is disposed above the bottom of the storage chamber 9, below the rear side of the seating seat 10 and above the rear wheel 16 near the rear frame 7. An air cleaner 30, a check valve 29 fixed to the power unit 13 and positioned below the air cleaner 30, an upstream secondary air introduction pipe 31 connecting the air cleaner 30 to the check valve 29, upstream secondary air induction pipe 31 and the same side of the vehicle width direction and a secondary air introduction pipe downstream secondary air injection tube 28 which connects the check valve 29 to the exhaust gas flow path structure And, the upstream secondary air induction pipe 31 leads air sucked from an air cleaner 30 to the check valve 29, and made to have a slack between the air cleaner 30 and the check valve 29 caused by the swing of the power unit 13 while absorbing a relative positional change between the exhaust muffler the downstream secondary air injection tube 28 forms a part is piping of the exhaust gas flow path between the suspension members 18 and 19 and the cylinder 17 25 is connected to a position higher than the lowest part.
[0011]
Further, in order to solve the above-mentioned problem, the scooter exhaust gas purifying apparatus according to the present invention is configured such that the vehicle body frame 2 is connected to the head pipe 5 and the down pipe extending rearward and downward from the head pipe 5 as described in claim 2. It comprises a tube 6 and a pair of left and right rear frames 7 extending upward and rearward from the down tube 6, and has a storage chamber 9 in which a helmet 8 can be stored below the seating seat 10. A power unit 13 that supports the wheel 16 is supported by a pivot shaft 21 that is mounted on the vehicle body frame 2 via suspension members 18 and 19, and the power unit 13 and the rear wheel 16 move up and down around the pivot shaft 21. is buffered by the buffer device 18, 19 while being swingable, air from the outside supplied to the exhaust gas flow path 25 of the power unit Secondary air induction pipe 28, 31 is provided which, by introducing air so as to re-combust the unburned components in the exhaust gas in the exhaust gas flow path of the power unit 13 from the secondary air induction pipe 28, 31 In the scooter exhaust gas purifier configured as described above, the exhaust gas purifier is located above the rear wheel 16 and near the rear frame 7 between the shock absorber 22, the seat 10 and the storage chamber 9. An air cleaner 30 disposed therein, a check valve 29 fixed to the power unit 13 and positioned below the air cleaner 30, and an upstream secondary air introduction pipe connecting the air cleaner 30 to the check valve 29. 31, constituted by a downstream secondary air introduction pipe 28 for connecting the check valve 29 into the exhaust gas passage on the same side of the upstream-side secondary air introducing pipe 31 in the vehicle width direction, wherein The relative position change between the air cleaner 30 and the check valve 29 with it to have a slack to the swing of the power unit 13 along with the flow side secondary air induction pipe 31 guides the air sucked from the air cleaner to the check valve 29 On the other hand, the downstream secondary air introduction pipe 28 is disposed between the cylinder 17 and the suspension members 18 and 19, and is higher than the lowest part of the exhaust muffler 25 which forms a part of the exhaust gas flow path. And it is connected below the position of the pivot shaft 21.
[0012]
[Action]
When the exhaust gas purifying device of the scooter is configured as described above, the downstream secondary air introduction pipe disposed particularly at a low position is protected from obstacles and stepping stones on a road surface by an exhaust muffler and a suspension member, and durability is improved. Damage can be effectively prevented.
[0013]
In addition, since the air cleaner is placed inside the high dead space generated near the storage room, the air cleaner can be installed at a high position without sacrificing the capacity of the storage room, and the dust and moisture to the secondary air can be increased. Contamination can be prevented.
[0014]
Further, the relative position change between the air cleaner and the check valve accompanying the swing of the power unit due to the slack of the upstream side secondary air introduction pipe is absorbed, while the check valve fixed to the power unit and the exhaust gas flow path Since there is no change in the relative position between them, there is no concern that the downstream secondary air introduction pipe will come off due to the swing of the power unit.
[0015]
【Example】
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a left side view of a scooter to which the present invention is applied. The scooter 1 has a general body layout. The body frame 2 includes a head pipe 5 supporting a front wheel 3 and a front fork 4, a down tube 6 extending downward and rearward from the head pipe 5, and a down tube 6. And a pair of left and right rear frames 7 extending rearward from the rear end to the upper part. A storage room 9 capable of storing a helmet 8 is provided on the rear frame 7, and a seat 10 is placed on the storage room 9 so as to be openable and closable. Such a body frame 2 and the storage room 9 are covered with a frame cover 11 made of a synthetic resin or the like, so that the appearance of the scooter 1 is adjusted.
[0016]
A power unit 13 of the scooter 1 has a swing case 15 extending rearward integrally connected to a left side surface of a crankcase 14 of the engine, and a rear wheel 16 rotatably supported on a rear right side surface of the swing case 15. The power transmission devices are built in the cylinder 15, and the cylinder 17 of the engine is arranged substantially horizontally from the front of the crankcase 14 to the front in order to avoid interference with the bottom of the storage chamber 9. It is installed to extend.
[0017]
FIG. 2 is a view taken in the direction of arrows II-II in FIG. As shown in FIGS. 1 and 2, a pair of left and right suspension arms 18, 18 extending to both sides of a lower portion of the cylinder 17 are formed integrally with the crankcase 14. It is pivotally connected to a pivot shaft 21 provided on the vehicle body frame 2 via links 19 and 19. The suspension arms 18, 18 and suspension links 19, 19 are collectively called suspension members. A shock absorber 22 is connected between the rear part of the swing case 15 and the rear frame 7. For this reason, the power unit 13 can rotate around the pivot shaft 21 and the pivot shaft 23 together with the rear wheel 16, and the buffer device 22 buffers the rotation of the power unit 13. As shown in FIG. 2, a forced air cooling fan device 24 for cooling the cylinder 17 is provided on the right side surface of the crankcase 14.
[0018]
The exhaust muffler 25 attached to the cylinder 17 extends from the lower surface of the cylinder 17 to the ground and has a shape that curves backward. The exhaust muffler 25 moves integrally with the rotation of the power unit 13 and the rear wheel 16.
[0019]
Next, an exhaust gas purifying apparatus according to the present invention will be described. A branch pipe 27 as shown in FIG. 2 is provided near the base end of the exhaust muffler 25, and a downstream secondary air introduction pipe 28 made of a heat-resistant rubber hose is connected to the branch pipe 27. The position of the branch pipe 27 is set to be higher than the lowest part 25 a of the exhaust muffler 25 and lower than the position of the pivot shaft 21. The branch pipe 27 and the downstream secondary air introduction pipe 28 are disposed between the cylinder 17 and the suspension members (suspension arms 18, 18 and suspension links 19, 19). The other end is connected to a check valve 29 installed above the cylinder 17.
[0020]
On the other hand, for example, a small air cleaner 30 is installed above the rear frame 7, and the air cleaner 30 and the check valve 29 are connected by an upstream secondary air introduction pipe 31 made of a heat-resistant rubber hose. The upstream secondary air introduction pipe 31 is slackened, and the relative position change between the air cleaner 30 and the check valve 29 due to the swing of the power unit 13 causes the slack of the upstream secondary air introduction pipe 31. Is absorbed by the expansion and contraction of Further, a rubber hose 32 having an open end is connected to the air cleaner 30.
[0021]
The installation position of the air cleaner 30 is located above the bottom of the storage chamber 9, below the rear side of the seat 10, above the rear wheel 16, and between the seat 10 and the shock absorber 22. This place is originally a dead space surrounded by the storage room 9, the seat 10, the frame cover 11, the rear wheel 16 and the shock absorber 22. The check valve 29 is located sufficiently below the air cleaner 30.
[0022]
When the engine operates, a positive pressure and a negative pressure due to the pulsation of the exhaust gas are generated alternately in the exhaust muffler 25. Since the check valve 29 allows only the airflow from the air cleaner 30 to the exhaust muffler 25, external air is sucked into the air cleaner 30 to remove dust only when the inside of the exhaust muffler 25 becomes a negative pressure, and as secondary air. It is introduced into the exhaust muffler 25. The secondary air introduced into the exhaust muffler 25 is mixed with the high-temperature exhaust gas, and oxygen in the secondary air reignites unburned components contained in the exhaust gas to completely burn the exhaust gas. Purify.
[0023]
Since the branch pipe 27 and the downstream secondary air introduction pipe 28 are located above the lowest portion 25a of the exhaust muffler 25, the branch muffler 25 guards the obstacle from obstacles on the road surface. In addition, the flying stones and the like which the front wheel 3 jumps up while the scooter 1 is running are shielded by the left suspension arm 18 and the suspension link 19 and do not directly hit the branch pipe 27 and the downstream secondary air introduction pipe 28. For this reason, even when the clearance between the vicinity of the base end of the exhaust muffler 25 and the road surface is small as in the scooter 1 of the present embodiment, breakage of the branch pipe 27 and the downstream secondary air introduction pipe 28 is effectively avoided. be able to.
[0024]
In addition, since the air cleaner 30 is disposed inside a high dead space that is originally generated near the storage room 9, the air cleaner 30 is installed at a high position without sacrificing the capacity of the storage room 9, and the secondary air It is possible to effectively prevent dust and moisture from being mixed into the water.
[0025]
Furthermore, since the upstream secondary air introduction pipe 31 is provided with slack, the relative position change between the air cleaner 30 and the check valve 29 due to the swing of the power unit 13 causes the upstream secondary air introduction pipe 31 to be slackened. While the relative position does not change between the check valve 2 fixed to the power unit 13 and the branch pipe 27. For this reason, there is no concern that the downstream secondary air introduction pipe 28 will come off due to the swing of the power unit 13.
[0026]
【The invention's effect】
As described above, according to the scooter exhaust gas purification apparatus of the present invention, the vicinity of the base end of the exhaust muffler to which the secondary air introduction pipes serving as the upstream air supply passage and the downstream air supply passage are connected and the road surface Even if the clearance between the secondary air introduction pipe is small, it is possible to effectively prevent the durability of the secondary air introduction pipe from being impaired, and to increase the air cleaner for secondary air purification without causing the secondary air introduction pipe to come off. It is possible to prevent dust and moisture from being mixed with the secondary air by being installed at the position beforehand and surely.
In addition, since the upstream air supply passage and the downstream air supply passage of the exhaust gas purifying device are on the same side in the vehicle width direction, workability and maintainability during assembly and maintenance at the vehicle are improved, and the power unit is improved. Even when swings, the secondary air is supplied smoothly and smoothly, and it is possible to effectively prevent the upstream and downstream air supply passages from being twisted to reduce the passage area of the air supply passage or to be deformed. In addition, the piping length can be shortened without using a complicated piping route.
Furthermore, the air cleaner is arranged at a high position near the rear frame below the rear side of the seat and above the rear wheel, and the rear frame passes near the air cleaner, so the air cleaner can be securely and stably attached to the body frame, etc. It is easy to fix, and even if the air cleaner is placed close to the body cover, the air cleaner is fixed stably, so that there is no mutual interference between the body cover and the storage room during running or contact. In addition, the air cleaner and the storage chamber can be disposed close to each other, and the air cleaner and the storage chamber can be easily obtained without sacrificing the capacity of the storage chamber.
[Brief description of the drawings]
FIG. 1 is a left side view of a scooter to which the present invention is applied.
FIG. 2 is a view showing one embodiment of the present invention as viewed from the direction of arrows II-II in FIG. 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Scooter 2 Body frame 8 Helmet 9 Storage room 10 Seating seat 13 Power unit 14 Crank case 15 Swing case 16 Rear wheel 17 Cylinder 18 Suspension arm 19 as a suspension member Suspension link 21 as a suspension member Pivot shaft 22 Buffer device 25 Exhaust gas Exhaust muffler 25a which is a flow passage Lowest part 27 of exhaust muffler Branch pipe 28 which serves as a connection between downstream secondary air introduction pipe and exhaust gas flow path Downstream secondary air introduction pipe 29 Check valve 30 Air cleaner 31 Upstream side Secondary air inlet tube 32 Rubber hose

Claims (2)

The vehicle body frame 2 comprises a head pipe 5, a down tube 6 extending rearward and downward from the head pipe 5, and a pair of right and left rear frames 7 extending upward and rearward from the down tube 6.
A storage room 9 capable of storing a helmet 8 below the seating seat 10 is provided,
A power unit 13 having a cylinder 17 substantially horizontal and a rear wheel 16 supported at a rear portion is supported by a pivot shaft 21 provided on the vehicle body frame 2 via suspension members 18 and 19, and the power unit 13 and the rear wheel are supported. 16 is swingable up and down around the pivot shaft 21 and is buffered by a buffer device 22,
The secondary air introduction pipe 28, 31 supplied air from the outside leads to the exhaust gas flow path of the power unit 13 is provided from the secondary air introducing pipe 28, 31 into the exhaust gas flow path of the power unit 13 In a scooter exhaust gas purification device configured to introduce air and reburn unburned components in the exhaust gas,
The exhaust gas purifying device includes an air cleaner 30 disposed above the bottom of the storage chamber 9, below the rear side of the seat 10 and near the rear frame 7 above the rear wheel 16,
A check valve 29 fixed to the power unit 13 and positioned below the air cleaner 30;
An upstream secondary air introduction pipe 31 connecting the air cleaner 30 to the check valve 29,
The upstream secondary air introduction pipe 31 and a downstream secondary air introduction pipe 28 connecting the check valve 29 to the exhaust gas flow path on the same side in the vehicle width direction;
The upstream secondary air introduction pipe 31 guides the air sucked from the air cleaner 30 to the check valve 29, and has a slack so that the air between the air cleaner 30 and the check valve 29 accompanying the swing of the power unit 13. While absorbing relative position changes,
The downstream side secondary air introduction pipe 28 is provided between the cylinder 17 and the suspension members 18 and 19 and is connected to a position higher than the lowest part of the exhaust muffler 25 constituting a part of the exhaust gas flow path. An exhaust gas purification device for a scooter. The vehicle body frame 2 comprises a head pipe 5, a down tube 6 extending rearward and downward from the head pipe 5, and a pair of right and left rear frames 7 extending upward and rearward from the down tube 6.
A storage room 9 capable of storing a helmet 8 below the seating seat 10 is provided,
A power unit 13 having a cylinder 17 substantially horizontal and a rear wheel 16 supported at a rear portion is supported by a pivot shaft 21 provided on the vehicle body frame 2 via suspension members 18 and 19, and the power unit 13 and the rear wheel are supported. 16 are swingable up and down around the pivot shaft 21 and are buffered by buffering devices 18 and 19.
An exhaust gas flow path of the power unit is the secondary air introducing pipe 28 and 31 air is supplied is provided externally, the air in the exhaust gas flow path of the power unit 13 from the secondary air induction pipe 28, 31 In a scooter exhaust gas purification device configured to introduce and reburn unburned components in exhaust gas,
An air cleaner 30 disposed above the rear wheel 16 and near the rear frame 7 between the shock absorber 22 and the seat 10 and the storage chamber 9;
A check valve 29 fixed to the power unit 13 and positioned below the air cleaner 30;
An upstream-side secondary air introduction pipe 31 that connects the air cleaner 30 to the check valve 29;
The upstream secondary air introduction pipe 31 is provided with a downstream secondary air introduction pipe 28 that connects the check valve 29 to an exhaust gas passage on the same side in the vehicle width direction,
The upstream secondary air introduction pipe 31 guides the air sucked from the air cleaner to the check valve 29 and has a slack so that the relative position change between the air cleaner 30 and the check valve 29 due to the swing of the power unit 13. While absorbing
The downstream secondary air introduction pipe 28 is piping between the cylinder 17 and the suspension members 18 and 19, the higher than the lowest portion of the exhaust muffler 25 constituting part of an exhaust gas flow path and said pivot axis An exhaust gas purifying apparatus for a scooter, wherein the exhaust gas purifying apparatus is connected below a position 21.

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