JPH06272551A - Secondary air device for motorcycle - Google Patents

Abstract

PURPOSE:To provide a secondary air device for a motorcycle capable of supplying the secondary air of oxygen necessary for purifying exhaust gas by using a pump or the like to utilize the pulsated waves of the exhausted gas without adding any points to the specification of an engine. CONSTITUTION:An exhaust manifold 17 having an outlet 20 branched into two branch pipes is connected to an exhaust port of an engine 10. Secondary air are respectively supplied to the rear side of the branched point of the exhaust manifold 17 through a pair of reed valves 14, a hose 14, hose 19 and secondary air pipe 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a secondary air device for a motorcycle.

[0002]

2. Description of the Related Art The exhaust gas of an internal combustion engine contains unburned components of fuel such as carbon monoxide. BACKGROUND ART Secondary air is injected into an exhaust pipe, a catalyst is attached, and exhaust gas is purified by causing an exhaust gas to undergo an oxidation reaction in an exhaust pipe and a muffler and recombusting. When there is an engine room like a car, there is a lot of space for installation, and there are few problems with an air cleaner and piping for secondary air, and an auxiliary device such as an air pump can be used.

In the case of a motorcycle, the engine is mounted so as to be exposed, and the space for mounting auxiliary equipment is small. Therefore, secondary air is diverted from the engine air cleaner, and a secondary air control valve is attached to the engine. See, for example, JP-A-59-110825.

[0004]

The exhaust gas purification device is
There are areas that need to be installed and areas that do not, and it is difficult to change the specifications of the engine depending on the destination, which complicates production and is difficult. Further, it is desirable that auxiliary devices such as a pump need not be used.

In view of the above point, the present invention utilizes the pulsating wave of the exhaust gas without modifying the specifications of the engine like a pump or the like, and uses the secondary air of oxygen necessary for purifying the exhaust gas. The purpose of the present invention is to obtain a secondary air device for a motorcycle capable of supplying air.

[0006]

In order to achieve the above object, a secondary air system for a motorcycle according to the present invention is configured such that an exhaust manifold of an engine is connected to an exhaust manifold having a bifurcated outlet. The hose and the secondary air are supplied to the rear side of the branch point from a pair of reed valves.

[0007]

By connecting an exhaust manifold having a bifurcated outlet to one exhaust port of the engine, a pair of left and right reed valves can be provided and secondary air can be supplied to two left and right positions of the exhaust manifold. In this way, by the pulsating wave of the exhaust gas, the air resistance can be reduced and a sufficient air amount can be secured by using the pair of left and right reed valves, and the muffler on the rear side of the exhaust amount connected to the exhaust manifold, It can be purified by oxidation reaction. And since the engine specifications need not be modified at all, the secondary air device can be easily attached and detached, and the production for each destination is less complicated.

[0008]

Embodiments of the present invention will be described below with reference to FIGS. The cleaner case 1 for the secondary air is a box-shaped one that is made by molding synthetic resin into the inside and the outside, and is fitted in the middle to form a box. The mating surface is a porous filter such as a sponge plate. It is sandwiched between two. The cleaner case 1 is vertically long so as to fit inside the front part of the frame side cover 3. The cleaner case 1 has a suction port 4 inside the upper end thereof, and a hose 5 guides it to the lower side of the seat 6 to prevent rainwater and the like from entering. An outlet 7 is provided outside the lower end of the cleaner case 1.
The cleaner case 1 is fastened with a screw to a bracket 9 which is fastened to the frame 8. An air cleaner 11 for intake of the engine 10 is also fastened to the bracket 9.

A bracket 13 is attached to the lower portion of the frame 8 where the fuel tank 12 is mounted, and a pair of left and right reed valves 14 are fastened to the bracket 13. A hose 15 is connected to the outlet 7 of the cleaner case 1, and the hose 15 extends upward on the front side of the cleaner case 1 and further extends the lower side of the fuel tank 12 to the front side so that the hose on the lower side of the bracket 13 is extended. The clamp 16 is stopped and extended to the front side of the reed valve 14, and bifurcated at the front side of the reed valve 14, bent backward in a loop shape and connected to the left and right reed valves 14.

An exhaust manifold 17 is connected to a cylinder exhaust port of the engine 10 to divide one exhaust port into two. Then, the secondary air pipe 1
8 is attached, and the two secondary air pipes 18 are connected to the left and right reed valves 14 by hoses 19. An exhaust pipe is connected to each of the two outlets 20 of the exhaust manifold 17, and a catalyst is attached to a front portion of a muffler connected to the exhaust pipe.

Exhaust of the engine 10 is intermittently and rapidly performed, and a pulsating wave of exhaust gas is generated in the exhaust manifold 17 and the exhaust pipe. Then, when this pulsating wave becomes a negative pressure, the reed valve 14 opens and the secondary air pipe 1
From 8, the secondary air is sucked into the exhaust manifold 17. With this secondary air, the catalytic body in the muffler causes an oxidation reaction to purify unburned components in the exhaust gas. Hose 15
Requires a desired length in order to effectively inhale the secondary air by utilizing the pulsating wave of the exhaust gas, and bypasses from the lower side of the cleaner case 1 to the front side of the reed valve 14 for a long time. Earn money. Also, the reed valve 14 is paired, and the outlet 20 of the exhaust manifold 17 is also doubled.
The exhaust resistance is reduced and the required amount of secondary air can be injected.

[0012]

As described above, since the present invention is configured as described above, the exhaust manifold 1 is utilized from the pair of left and right reed valves 14 by utilizing the pulsating wave of exhaust gas.
It is possible to purify the exhaust gas by supplying secondary air with a small air resistance and a sufficient amount of air to two places on the left and right sides behind the branch point of 7.
Further, in the engine 10, the secondary air device can be attached / detached simply by plugging the secondary air inlet of the exhaust manifold 17, and there is almost no change in the specifications of the engine 10, which makes it difficult for each destination. Therefore, the performance of the engine 10 can be made stable.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of the present invention.

FIG. 2 is a plan view showing an embodiment of the present invention.

FIG. 3 is a front view of a cleaner case portion showing an embodiment of the present invention.

FIG. 4 is a sectional view taken along the line AA of FIG. 3 showing an embodiment of the present invention.

FIG. 5 is a front view of the bracket of the cleaner case showing the embodiment of the present invention.

FIG. 6 is a plan view of a reed valve bracket showing an embodiment of the present invention.

FIG. 7 is a view on arrow B of FIG. 6 showing an embodiment of the present invention.

FIG. 8 is a front view of an exhaust manifold showing an embodiment of the present invention.

FIG. 9 is a bottom view of the exhaust manifold showing the embodiment of the present invention.

FIG. 10 is a vertical sectional side view of a reed valve showing an embodiment of the present invention.

FIG. 11 is a plan view of a reed valve showing an embodiment of the present invention.

[Explanation of symbols]

 10 Engine 14 Reed Valve 17 Exhaust Manifold 18 Secondary Air Pipe 19 Hose 20 Outlet

Claims (1)

[Claims] 1. An exhaust manifold having a bifurcated outlet is connected to an exhaust port of an engine, and secondary air is introduced from a pair of reed valves to a rear side of a branch point of the exhaust manifold via a hose and a secondary air pipe. A secondary air device for a motorcycle, characterized in that each is supplied.