JP3237285B2 - Secondary air supply for exhaust gas purification of motorcycles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a secondary air supply device for purifying exhaust gas of a motorcycle for purifying unburned components in exhaust gas.

[0002]

2. Description of the Related Art In an engine of an automobile, secondary air is injected into an exhaust manifold of an engine, a catalyst is attached to an exhaust system, and the exhaust gas into which the secondary air is injected is passed through the catalyst to cause an oxidation reaction. To reburn and purify unburned components in the exhaust gas. In the case of a car, the engine is mounted in the engine room, and there is room in the engine room, so that it is less troublesome to mount the secondary air device. On the other hand, in the case of a motorcycle, the engine appears to be exposed and the space for mounting the secondary air device is small. Therefore, conventionally, secondary air is used separately from the air cleaner of the engine. In addition, a control valve for secondary air is attached to a cylinder head or the like of the engine.
No. 25).

[0003]

However, if the air cleaner shares the secondary air with the intake air of the engine,
It has a slight effect on engine performance. Also,
The control valve is susceptible to vibration and must be equipped with an anti-vibration device to be mounted on the engine or vehicle body.
The configuration becomes complicated.

[0004] The present invention has been made in view of the above, and an air cleaner dedicated to secondary air is provided to prevent a change in engine performance, while a switching valve is held by a piping hose, and a special device is provided. It is an object of the present invention to provide a secondary air supply device for purifying exhaust gas of a motorcycle, which can perform vibration isolation without applying the same and can maintain a predetermined function.

[0005]

According to the first aspect of the present invention, to achieve the above object, an engine is mounted below and behind a head pipe supporting a front wheel, and exhaust gas is provided behind the head pipe. A secondary air supply comprising an air cleaner for purifying secondary air for purification, a reed valve communicating with the exhaust passage of the engine and opening and closing with an exhaust pulsation wave, and a switching valve opening and closing with a negative intake air pressure of the engine. Device, wherein the switching valve is located between the air cleaner and the reed valve and above the reed valve, and the reed valve is distributed to the left and right in a vehicle plan view above the engine. At the same time, elastic hoses protrude upward from the upper walls of both reed valves, respectively.
The switching valve is interposed and connected between the other ends of the left and right elastic hoses.

[0006] The air cleaner for purifying secondary air for purifying exhaust gas, the reed valve communicating with an exhaust passage of the engine and opening and closing with an exhaust pulsation wave,
It is preferable that a secondary air supply device including a switching valve that opens and closes with a negative intake air pressure of the engine is mounted between a pair of left and right main tubes extending left and right in a plan view from behind a head pipe supporting the front wheels. Further, it is preferable that the switching valve is disposed between a pair of left and right main tubes extending left and right in a plan view from the rear of the head pipe supporting the front wheels and substantially at the center above the engine cylinder head.

According to the present invention, the air cleaner of the secondary air device is provided separately from the air cleaner for intake of the engine, so that the performance of the engine can be prevented from being affected. In addition, the switching valve is elastically held by the elasticity of the rubber connecting the air cleaner to the switching valve and the hose connecting the switching valve to the left and right reed valves. Erroneous operation due to vibration can be prevented. Since no special parts are used for mounting the switching valve, low cost can be expected.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to the drawings. A secondary air supply device for purifying exhaust gas of a motorcycle according to the present embodiment is shown in FIGS. In addition, the switching valve 4 is located between the air cleaner 1 and the reed valve 12 and above the reed valve 12, and the reed valve 12 is disposed above and below the engine 9 so as to be distributed to the left and right in a vehicle plan view. Elastic hoses 11, 11 project upward from the upper walls of both reed valves 12, respectively, and the switching valve 4 is interposed and connected between the other ends of the left and right elastic hoses 11, 11. Are elastically supported by both elastic hoses 11 and 11 for vibration isolation.

The air cleaner 1 is for exclusive use with secondary air, and is made of a synthetic resin which is divided into upper and lower parts and is fitted in the middle. A filter plate such as a porous sponge plate or the like is provided on the mating surface. It is sandwiched. The air cleaner 1 is provided with a suction port 2 on the upper side, and a lower outlet is connected to a switching valve 4 by a hose 3. As shown in FIG. 6, the switching valve 4 is designed so that when a negative pressure is applied to the upper negative pressure chamber 5, the valve 6 opens against a spring 7, and the negative pressure chamber 5 is connected to the engine 9 by a thin hose 8. The intake manifold 10 is opened at a pressure equal to or higher than a predetermined negative pressure in the intake manifold 10. The outlet of the switching valve 4 is connected to the left and right reed valves 12 by a hose 11.

The air cleaner 1 is fastened to the center of the bracket 13, and the left and right reed valves 12 are mounted on the bracket 13.
To the left and right of The front end of the bracket 13 is fastened to a mounting plate 17 between the left and right main tubes 16 on the rear side of the head pipe 15 at the front end of the frame 14. The bracket 13 is provided with two rows of screw holes 18 at the front and rear, so that a place where the bracket 13 is mounted on the mounting plate 17 can be selected. The same effect is obtained even if the holes on the mounting plate 17 side are arranged in two rows.

The switching valve 4 is held by elastic hoses 3, 11 by a hose 3 connected to the hose 3 and a hose 11 connected to the left and right reed valves 12, and is vibration-proof so that the influence of vibration is small. The left and right reed valves 12
As shown in FIGS. 9 to 11, two outlets are provided, and the exhaust holes 1 of each cylinder of the four-cylinder engine 9 are provided.
9 is connected to a hose 20 and a secondary air pipe 21. The secondary air pipe 21 is made of a pipe material so as to withstand the heat of the exhaust hole 19. A catalyst body is mounted in the muffler on the rear side of the exhaust pipe connected to each exhaust hole 19.

When the pressure in the intake manifold 10 of the engine 9 becomes higher than the set pressure, the valve 6 is lifted and opened by the negative pressure in the negative pressure chamber of the switching valve 4, and the secondary air from which dust is removed by the air cleaner 1 is removed. Flows from the hose 11 to the reed valve 12 via the hose 3 and the switching valve 4. When a negative pressure is generated due to the pulsation of the exhaust gas in the exhaust hole 19 flowing intermittently, the reed valve 1
2 is opened, and the secondary air is supplied to the exhaust hole 19 from the hose 20 and the secondary air pipe 21. As a result, the exhaust gas is supplemented with oxygen, touches the catalyst body in the muffler, oxidizes and reburns, and the unburned components of the fuel in the exhaust gas are purified.

[0013]

As described above, according to the present invention, the air cleaner is dedicated to the secondary air and is separate from the air cleaner for the intake of the engine, and therefore does not affect the engine performance. Also, since the switching valve is held by three rubber hoses, a hose connecting the air cleaner and the switching valve and a hose connecting the switching valve and the left and right reed valves, vibration can be prevented, Vibration of the engine and the frame can be reduced, and malfunction can be prevented. Furthermore, since it is not necessary to use a special component for mounting the switching valve, there is an effect that the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a side view of an essential part showing an embodiment of a secondary air supply device for purifying exhaust gas of a motorcycle according to the present invention.

FIG. 2 is a plan view of a main part showing an embodiment of a secondary air supply device for purifying exhaust gas of a motorcycle according to the present invention.

FIG. 3 is a side view showing an entire engine in the embodiment of the secondary air supply device for purifying exhaust gas of a motorcycle according to the present invention.

FIG. 4 is a plan view showing the entire engine in the embodiment of the secondary air supply device for purifying exhaust gas of a motorcycle according to the present invention.

FIG. 5 is a side view of a main part showing an embodiment of a secondary air supply device for purifying exhaust gas of a motorcycle according to the present invention.

FIG. 6 is a longitudinal sectional view of a switching valve showing an embodiment of a secondary air supply device for purifying exhaust gas of a motorcycle according to the present invention.

FIG. 7 is a side view showing a bracket in the embodiment of the secondary air supply device for purifying exhaust gas of a motorcycle according to the present invention.

FIG. 8 is a bottom view showing a bracket in the embodiment of the secondary air supply device for purifying exhaust gas of a motorcycle according to the present invention.

FIG. 9 is a plan view showing a reed valve in the embodiment of the secondary air supply device for purifying exhaust gas of a motorcycle according to the present invention.

FIG. 10 is a longitudinal sectional side view showing a reed valve in the embodiment of the secondary air supply device for purifying exhaust gas of a motorcycle according to the present invention.

FIG. 11 is a bottom view showing a reed valve in the embodiment of the secondary air supply device for purifying exhaust gas of a motorcycle according to the present invention.

FIG. 12 is a side view showing an entire motorcycle in an embodiment of a secondary air supply device for purifying exhaust gas of a motorcycle according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Air cleaner 3 Hose 4 Switching valve 9 Engine 11 Hose 12 Reed valve 13 Bracket 14 Frame 15 Head pipe 19 Cylinder exhaust hole

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F01N 3/34 F01N 3/30 F02B 75/10

Claims (3)

(57) [Claims] An engine is mounted below and behind a head pipe supporting a front wheel, and an air cleaner for purifying secondary air for purifying exhaust gas is provided behind the head pipe. A motorcycle including a reed valve that communicates and opens and closes with an exhaust pulsation wave, and a secondary air supply device that includes a switching valve that opens and closes with an intake negative pressure of the engine, wherein the switching valve is an air cleaner and the reed valve And the reed valve is positioned above the reed valve, and the reed valves are separately arranged on the left and right in a vehicle plan view above the engine, and the elastic hoses are respectively directed upward from the upper walls of both reed valves. And the switching valve is interposed between the other ends of the left and right elastic hoses. Exhaust gas purifying secondary air supply system for a motorcycle that. 2. The air cleaner for purifying secondary air for purifying exhaust gas, the reed valve communicating with an exhaust passage of the engine and opening and closing by an exhaust pulsation wave, and opening and closing by an intake negative pressure of the engine. The exhaust gas purifying apparatus for a motorcycle according to claim 1, wherein a secondary air supply device including a switching valve is mounted between a pair of left and right main tubes extending left and right in a plan view from behind a head pipe supporting the front wheels. Secondary air supply. 3. The switching valve is disposed between a pair of left and right main tubes extending left and right in a plan view from behind a head pipe supporting the front wheels and substantially at the center above an engine cylinder head. The secondary air supply device for purifying exhaust gas of a motorcycle according to the above.