JPH06270878A - Secondary air device for motorcycle - Google Patents

Abstract

PURPOSE:To provide a secondary air device of a motorcycle which can be mounted and dismounted easily and is convenient for maintenance by providing an air cleaner exclusively for secondary air, mounting the parts related to the secondary air device on one bracket, and fixing by tightening a front end of the bracket on a mounting plate of a frame. CONSTITUTION:An air cleaner l and lead valves 12 on the right and left are fixed by tightening them, and a bracket 13 which holds a switching valve 4 is provided. A front end of the bracket 13 is fixed by tightening it on a mounting plate 17 provided on the rear side of a head pipe 15 of a frame 14. The air cleaner 1 is fixed by tightening it at the center of the bracket, and a pair of read valves 12 on the right and left are fixed by tightening them on both sides of the bracket 13.

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, which purifies unburned components in exhaust gas.

[0002]

2. Description of the Related Art In an engine for an automobile or the like, secondary air is injected into an exhaust manifold of the engine, a catalyst is attached to an exhaust system, and exhaust gas into which the secondary air is injected is passed through the catalyst to cause oxidation reaction. It is made to wake up and reburn to purify. In the case of automobiles, the engine is installed in the engine room, and there is plenty of room in the engine room, so there is little difficulty in installing the secondary air device.

In the case of a motorcycle, the engine appears to be exposed. Then, the secondary air is branched from the air cleaner of the engine and taken out, or a control valve for the secondary air is attached to a cylinder head of the engine or the like to utilize a part of the engine to make a compact device.
See, for example, JP-A-59-110825.

[0004]

When the secondary air is branched and taken out from the air cleaner for intake of the engine, it has a delicate influence on the engine performance. Further, if a secondary air control valve or the like is attached to the cylinder head or the like of the engine, it has to be removed during maintenance such as adjustment of valve timing, which is troublesome in maintenance.

In view of the above point, the present invention provides an air cleaner dedicated to secondary air, mounts the parts related to the secondary air device on one bracket, and fastens the front end of the bracket to the mounting plate of the frame. It is an object of the present invention to obtain a secondary air device for a motorcycle, which can be easily attached and detached and is convenient for maintenance.

[0006]

In order to achieve the above object, a secondary air device for a motorcycle according to the present invention has an air cleaner and left and right reed valves fastened together with a bracket holding a switching valve. The front end of the bracket is fastened to a mounting plate provided on the rear side of the head pipe of the frame. The air cleaner is fastened to the center of the bracket, and the left and right reed valves are fastened to both sides of the bracket.

The air cleaner can be dedicated to the secondary air so as not to affect the engine performance. An air cleaner related to the secondary air device, left and right reed valves, and a switching valve are attached to the bracket all together. The only parts that connect to the engine are the secondary air pipe and the negative pressure extraction hose of the switching valve.The bracket can be removed by simply attaching and removing the front end from the frame mounting plate. Is easy and convenient for engine maintenance.

[0008]

Embodiments of the present invention will be described below with reference to FIGS. The air cleaner 1 is for secondary air only, and it is made by molding synthetic resin into upper and lower parts so that it fits in the middle, and a filter plate such as a porous sponge plate is sandwiched between the mating surfaces. is there. The air cleaner 1 is provided with an intake port 2 on the upper side, and the 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 negative pressure is applied to the upper negative pressure chamber 5, the valve 6 opens against the spring 7, and the negative pressure chamber 5 uses a thin hose 8 for the engine 9 The intake manifold 10 is connected to the intake manifold 10 to open at a predetermined negative pressure or higher. Switching valve 4
The outlet of 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 fastened to the left and right of the bracket 13. The bracket 13 has its front end 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 the rear so that when mounting on the mounting plate 17, the location can be selected. Even if the holes on the mounting plate 17 side are arranged in two rows, the same effect can be obtained. The switching valve 4 is held by the elastic hoses 3 and 11 by the hose 3 connected to it and the hoses 11 connected to the left and right reed valves 12, and is vibration-isolated so that the influence of vibration is small. As shown in FIGS. 9 to 11, each of the left and right reed valves 12 is provided with two outlets, and a hose 20 and a secondary air pipe 21 are provided in an exhaust hole 19 of each cylinder of the four-cylinder engine 9. Link. 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 negative pressure in the intake manifold 10 of the engine 9 exceeds a preset value, 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 has been removed by the air cleaner 1. Flows from the hose 11 to the reed valve 12 via the hose 3 and the switching valve 4. Then, when negative pressure is generated due to the pulsation of the exhaust gas that rapidly and intermittently flows in the exhaust hole 19, the reed valve 12 opens and the secondary air flows from the hose 20 and the secondary air pipe 21 to the exhaust hole 19. Is supplied. As a result, the exhaust gas is supplemented with oxygen, comes into contact with the catalytic body in the muffler, undergoes an oxidation reaction, and re-combusts, and the unburned components of the fuel in the exhaust gas are purified.

[0011]

As described above, since the present invention is constructed as described above, it is possible to dedicate the air cleaner 1 to the secondary air so as not to affect the engine performance. Then, the main parts of the secondary air device are collectively attached to one bracket 13, and the bracket 13 is attached.
Since the front end of the engine is fastened to the mounting plate 17 of the frame 14, it can be easily attached and detached, and the time and effort required for maintenance of the engine 9 can be reduced. Further, the bracket 13 is close to the exhaust hole 19 of the engine 9 and requires a short piping.
There are few visible parts in the space between the two and the appearance is good.

[Brief description of drawings]

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

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

FIG. 3 is a side view of the entire engine showing an embodiment of the present invention.

FIG. 4 is a plan view of the entire engine showing an embodiment of the present invention.

FIG. 5 is a side view of a main part of a secondary air device showing an embodiment of the present invention.

FIG. 6 is a vertical sectional view of a switching valve showing an embodiment of the present invention.

FIG. 7 is a side view of a bracket showing an embodiment of the present invention.

FIG. 8 is a bottom view of the bracket showing the embodiment of the present invention.

FIG. 9 is a plan view of a reed valve showing an 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 bottom view of the reed valve showing the embodiment of the present invention.

FIG. 12 is a side view of the entire motorcycle showing an embodiment of the present invention.

[Explanation of symbols]

 1 Air Cleaner 4 Switching Valve 12 Reed Valve 13 Bracket 14 Frame 15 Head Pipe 17 Mounting Plate

Claims (2)

[Claims] 1. An air cleaner and left and right reed valves are fastened together, a bracket holding a switching valve is provided, and a front end of the bracket is fastened to a mounting plate provided on a rear side of a head pipe of a frame. A secondary air device for a motorcycle characterized by the above. 2. A secondary air system for a motorcycle according to claim 1, wherein an air cleaner is fastened to the center of the bracket, and a pair of left and right reed valves are fastened to both sides of the bracket.