JP3127527B2 - Scooter exhaust purification system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scooter exhaust gas purification apparatus for completely burning unburned components contained in exhaust gas.

[0002]

2. Description of the Related Art As an exhaust gas purifying apparatus used for a motorcycle, outside air (secondary air) is mixed in an exhaust gas flow path of an engine, and harmful unburned components contained in the exhaust gas are re-ignited to complete the exhaust gas. Some promote combustion.

An example of such an exhaust gas purifying apparatus is disclosed in, for example, Japanese Utility Model Laid-Open No. 62-14114. This exhaust gas purification device (secondary air supply device) has an air supply passage leading to an exhaust port of an engine, a reed valve as a check valve inside the air supply passage, and an upstream side of the air supply passage. An air cleaner is installed. The air supply path is formed inside the cylinder of the engine, and its upstream side is connected to the frame pipe of the body frame via a short pipe. An air cleaner is installed inside the frame pipe.

Since the reed valve opens and closes due to a change in pressure caused by exhaust pulsation in the exhaust port, by arranging the reed valve as close to the exhaust port as possible as described above, the reed valve has good open / close response. To enhance the exhaust purification action.

[0005]

However, the above exhaust gas purifying device is based on the premise that the engine is completely fixed to the vehicle body frame and does not move relative to the vehicle body frame. When one unit is formed together with the rear wheel and vibrates violently with respect to the body frame, the tube connecting the air supply path (reed valve) and the air cleaner is easily pulled out, and the action of the exhaust gas purification device is reduced. Exhaust gas leakage may occur at the same time as loss. In addition, when the engine unit is attached to and detached from the vehicle body, the tube also needs to be attached and detached, and workability is extremely poor.

In addition, since the air supply passage is formed inside the cylinder of the engine, the structure of the engine becomes complicated, and the cylinder becomes incompatible with an engine having no exhaust gas purifying device. And it becomes difficult to manufacture a motorcycle.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a high exhaust gas purifying action can be obtained by a simple structure. It is an object of the present invention to provide a scooter exhaust gas purifying apparatus which makes it difficult for an air supply passage connecting a stop valve and an air cleaner to come off, and can improve the workability of attaching and detaching an engine unit.

[0008]

In order to achieve the above object, a scooter exhaust purifying apparatus according to the present invention comprises an engine having a rear wheel pivotally supported at a rear portion thereof. The front part of the unit is pivotally supported on a horizontal support shaft provided on the vehicle body frame, and the engine unit and the rear wheel are swingable up and down around the horizontal support shaft. In a scooter exhaust purification device configured to be provided with an air supply passage communicating from the outside, and to introduce external air into the exhaust gas passage from the air supply passage to re-ignite unburned components in the exhaust gas,
An air cleaner fixed above the horizontal support shaft and at the rear of the vehicle body, a check valve fixed separately to the engine unit and positioned forward of the air cleaner from the vehicle body, and the air cleaner An upstream air supply path connected to the check valve, and a downstream air supply path connecting the check valve to the exhaust gas flow path,
The upstream air supply passage guides the outside air sucked from the air cleaner to the check valve and absorbs a relative position change between the air cleaner and the check valve accompanying the swing of the engine unit. The outside air passing through the check valve is introduced into the exhaust gas flow path and mixed with the exhaust gas.

According to a second aspect of the present invention, in the scooter exhaust gas purifying apparatus according to the present invention, the check valve is provided together with the components of the engine unit. Fastened to the unit.

Further, the scooter exhaust gas purifying apparatus according to the present invention, as described in claim 3,
In the configuration of claim 1, the downstream air supply passage connects between the branch pipe branched from the most upstream part of the exhaust gas passage to the outside and the check valve.

[0011]

According to the first aspect of the present invention, a sufficient distance is provided between the air cleaner and the check valve, and the upstream air supply path becomes longer. The upstream air supply passage is difficult to come off even if it violently swings with respect to the body frame together with the wheels. Moreover, since it is not necessary to attach and detach the upstream air supply passage when attaching and detaching the engine unit, the attaching and detaching workability is improved.

In addition, since the check valve is provided separately from the engine unit, the structure of the engine unit is kept simple, and the check valve is compatible with the engine unit having no exhaust gas purification device. And facilitates the production of engine units and scooters.

According to the second aspect of the present invention, when the check valve is attached to the engine unit by using a dedicated fixing member or the like, or when the check valve is integrally provided in a component or the like of the engine unit, In comparison, the structure of the engine unit is simplified.

Further, according to the third aspect of the present invention, a simple structure in which a branch pipe is provided at the most upstream portion of the exhaust gas flow path and the downstream air supply path is connected, so that outside air is supplied to the high-temperature exhaust gas. Since it can be introduced and the unburned components in the exhaust gas can be completely burned, a high exhaust gas purifying action can be obtained.

[0015]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a left side view of a scooter to which an embodiment of an exhaust gas purifying apparatus according to the present invention is applied. This scooter 1 has a general body layout, and an engine unit 3 is installed at a lower rear portion of a body frame 2.
The engine unit 3 is supported by a horizontal support shaft 5 extending in the vehicle width direction at a center lower portion of the body frame 2 together with a rear wheel 4 supported by a rear portion. Numeral 4 can swing up and down around a horizontal support shaft 5.

The cylinder 6 of the engine unit 3 is horizontally arranged forward, and an exhaust pipe 8 of an exhaust muffler 7 is connected to a lower surface of the cylinder 6. Further, a carburetor 11 is attached to an upper part of the crankcase 9 of the engine unit 3.

The exhaust gas purifying apparatus 12 according to the present invention includes an air cleaner 13, a check valve 14, a rubber hose 15 as an upstream air supply passage, and a rubber hose 16 as a downstream air supply passage. As shown in FIG. 2, the air cleaner 13 and the check valve 14 are connected by a rubber hose 15, and a branch pipe 17 branched to the outside from an uppermost stream portion of the exhaust pipe 8 as an exhaust gas flow path. A rubber hose 16 is connected to the check valve 14.

The air cleaner 13 is fixed to the rear of the vehicle body so as to be located above and behind the horizontal support shaft 5,
The check valve 14 is separately fixed to the engine unit 3 and is located forward of the air cleaner 13 in the vehicle body.

The check valve 14 is of a reed valve type, for example, and has a valve body 18 as shown in FIGS.
The inside is formed of an inlet 21 and an outlet 2 by a partition wall 19.
2, a reed valve 24 is provided in the vent hole 23 of the partition wall 19 to allow only the air flow from the inlet 21 to the outlet 22. Reference numeral 25 denotes a stopper that regulates the opening amount of the reed valve 24.

Rubber hose 1 extending from air cleaner 13
5 is connected to a union 26 on the inlet 21 side of the check valve 14, and the rubber hose 16 connected to the exhaust pipe 8 is connected to a union 27 on the outlet 22 side of the check valve 14.

As shown in FIGS. 5 and 6, the check valve 14
Is fastened to the engine unit 3 together with the intake manifold 29 of the carburetor 11, which is a component of the engine unit 3, via, for example, a plate-like bracket 28, and is disposed above the cylinder 6. The bracket 28 may be integrated with the check valve 14.

When the engine unit 3 is operated, a positive pressure and a negative pressure due to the pulsation of the exhaust gas are alternately applied to the exhaust pipe 8. . And
Only when the inside of the exhaust pipe 8 has a negative pressure, the outside air removed by the air cleaner 13 passes through the check valve 14 and is introduced into the exhaust pipe 8 through the rubber hoses 15 and 16. The introduced air is mixed with the high-temperature exhaust gas in the exhaust pipe 8, and the unburned components contained in the exhaust gas are re-ignited by the oxygen contained in the air, and the exhaust gas is purified by complete combustion. .

The check valve 14 is disposed at an upper portion of the cylinder 6 as described above and is located near the exhaust pipe 8, so that the rubber hose 16 for connecting the check valve 14 and the exhaust pipe 8 is provided. Can be reduced as much as possible, whereby the open / close responsiveness of the check valve 14 can be improved to prevent the exhaust gas from flowing backward, and the exhaust gas purifying action can be improved. Further, since the check valve 14 moves integrally with the engine unit 3, there is no relative movement between the check valve 14 and the engine unit 3, and the rubber hose 16 is pulled out even if the engine unit 3 swings violently. Don't worry about getting out.

On the other hand, since the air cleaner 13 is fixed above the rear part of the vehicle body and is sufficiently separated from the horizontal support shaft 5 of the engine unit 3, the length of the rubber hose 15 connecting the air cleaner 13 and the check valve 14 is increased. be able to.
Therefore, even if the engine unit 3 swings violently with respect to the vehicle body frame 2 together with the rear wheel 4, the relative position change between the air cleaner 13 and the check valve 14 due to the swing is absorbed by the curvature of the rubber hose 15. , Rubber hose 15
Is difficult to get out of the air cleaner 13 and the check valve 14. Moreover, since it is not necessary to attach and detach the rubber hoses 15 and 16 when attaching and detaching the engine unit 3 from the vehicle body, the workability of attaching and detaching the engine unit 3 is good.

Since the check valve 14 is provided separately from the engine unit 3, the structure of the engine unit 3 is kept simple, and the check valve 14 is provided between the engine unit 3 and the engine unit without the exhaust purification device 12. The components are interchangeable and the production of the engine unit 3 and the scooter 1 is facilitated.

Further, since the check valve 14 is fastened to the engine unit 3 together with the intake manifold 29, the check valve 14 can be attached to the engine unit 3 using a dedicated fixing member or the like, or the components of the engine unit can be used. The structure of the engine unit 3 can be simplified as compared with the case where the check valve is integrally provided.

Further, by a simple configuration in which the rubber hose 16 is connected to the branch pipe 17 branched from the uppermost stream of the exhaust pipe 8 to the outside, it is possible to introduce outside air into the high-temperature exhaust gas, so that the exhaust It is possible to improve the reignition property of the burned component and completely burn the unburned component to obtain a high exhaust gas purifying action.

In this embodiment, the check valve 14 is fastened together with the intake manifold 29 to the engine unit 3. However, as long as the components of the engine unit 3 are not limited to the intake manifold 29, for example, the cylinder 6, Alternatively, the check valve 14 may be fastened to the engine unit 3 together with mounting screws such as the belt case 31 shown in FIG.

[0030]

As described above, the scooter exhaust purifying apparatus according to the present invention comprises an air cleaner having an engine unit fixed to a rear portion of a vehicle body above a horizontal support shaft for supporting the vehicle body frame, and an engine cleaner for the engine unit. A check valve which is separately fixed and is located in front of the vehicle body with respect to the air cleaner, an upstream air supply path connecting the air cleaner to the check valve, and an exhaust gas flow passage of the engine unit for the check valve And a downstream air supply passage connected to the air supply passage. The upstream air supply passage guides the outside air sucked from the air cleaner to the check valve, and the space between the air cleaner and the check valve accompanying the swing of the engine unit. The relative position change is absorbed, and the outside air passing through the check valve by the downstream air supply path is introduced into the exhaust gas flow path and mixed with the exhaust gas. It is intended to.

With the above-described structure, it is possible to eliminate the concern that the upstream air supply passage is disconnected from the air cleaner or the check valve when the engine unit swings, and to attach / detach the upstream air supply passage when attaching / detaching the engine unit. This eliminates the necessity and improves the workability of attachment and detachment, and also simplifies the structure of the engine unit, thereby facilitating the manufacture of the engine unit and the scooter.

Also, in the scooter exhaust purification device according to the present invention, the check valve is fastened to the engine unit together with the components of the engine unit, so that the check valve is attached to the engine unit using a dedicated fixing member or the like. The structure of the engine unit can be simplified as compared with a case in which the check valve is integrally mounted or provided on a component part of the engine unit or the like.

Further, in the scooter exhaust purifying apparatus according to the present invention, the downstream air supply passage connects between the branch pipe branched from the most upstream part of the exhaust gas flow path to the outside and the check valve. Therefore, it is possible to introduce outside air into the high-temperature exhaust gas with a simple configuration, to completely burn unburned components in the exhaust gas, and to obtain a high exhaust gas purification action.

[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 left side view showing a layout of the exhaust gas purification device.

FIG. 3 is a plan view of a check valve.

FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3;

FIG. 5 is an enlarged left side view showing the vicinity of a check valve.

FIG. 6 is an enlarged plan view showing the vicinity of a check valve.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Scooter 3 Engine unit 4 Rear wheel 5 Horizontal support shaft 6 Cylinder 8 Exhaust pipe which is an exhaust gas passage 11 Carburetor which is a component of engine unit 12 Exhaust purification device 13 Air cleaner 14 Check valve 15 It is an upstream side air supply path. Rubber hose 16 Rubber hose as downstream air supply passage 17 Branch pipe 24 Reed valve 28 Bracket 29 Intake manifold as a component of engine unit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B62M 7/02 B62J 39/00 B62K 11/00 F01N 3/32

Claims (3)

(57) [Claims] 1. A front portion of an engine unit having a rear wheel pivotally supported at a rear portion thereof is supported by a horizontal support shaft provided on a body frame, and the engine unit and the rear wheel swing up and down around the horizontal support shaft. An air supply passage is provided, which is movable, and communicates with the outside of the exhaust gas passage of the engine unit. From the air supply passage, outside air is introduced into the exhaust gas passage to recycle unburned components in the exhaust gas. In a scooter exhaust purification device configured to ignite, the exhaust purification device is:
An air cleaner fixed above the horizontal support shaft and at the rear of the vehicle body, a check valve fixed separately to the engine unit and positioned forward of the air cleaner relative to the vehicle body,
An upstream air supply path connecting the air cleaner to the check valve; and a downstream air supply path connecting the check valve to the exhaust gas flow path. To the check valve and absorb the relative position change between the air cleaner and the check valve accompanying the swing of the engine unit, and remove the outside air passing through the check valve by the downstream air supply path. An exhaust purification device for a scooter, wherein the exhaust gas is introduced into the exhaust gas passage and mixed with the exhaust gas. 2. The engine valve according to claim 1, wherein the check valve is fastened to the engine unit together with components of the engine unit.
2. The scooter exhaust purification device according to claim 1. 3. The scooter exhaust purification system according to claim 1, wherein the downstream air supply passage connects between the branch pipe branched from the uppermost stream portion of the exhaust gas passage to the outside and the check valve. apparatus.