JP3108876B2 - Motorcycle intake air intake system - Google Patents

Description

Description: TECHNICAL FIELD [0001] The present invention relates to an intake air introduction device for a motorcycle, and more particularly, to an intake air introduction device for a motorcycle that introduces outside air to an intake system from a front end of a fuel tank.

2. Description of the Related Art There is a motorcycle in which a fuel tank is mounted on a main frame, and an intake system of an internal combustion engine is arranged below the fuel tank. In such a motorcycle, particularly in a racer, a large amount of outside air needs to be introduced into an intake system during traveling, but a closed space below the fuel tank is difficult to introduce outside air due to traveling in some cases.

For this reason, as described in, for example, Japanese Utility Model Laid-Open Publication No. 61-117082, an external air introduction pipe for introducing external air into an intake system is provided so as to pass through the front end of a fuel tank.

[Problems to be Solved by the Invention] However, since the intake system is arranged below the fuel tank and the outside air introduction pipe penetrates the tank chamber of the fuel tank, the volume of the tank chamber increases accordingly. As a result, securing the air cleaner for the intake system is limited.

Also, since the outside air introduction pipe penetrates through the upper plate and the lower plate forming the tank chamber of the fuel tank, it is necessary to weld this through portion in order to maintain the confidentiality. It takes time and effort to manufacture and increases the manufacturing cost.

Furthermore, since the penetration portion is provided in the tank chamber of the fuel tank, the rigidity of the tank chamber may be reduced.

The present invention has been made in view of such circumstances,
It is an object of the present invention to provide a motorcycle intake introduction device that can easily secure the volume of an air cleaner, minimize the influence on a fuel tank, and efficiently introduce air.

[Means for Solving the Problems] In order to solve the problems and achieve the object, the present invention is configured as follows.

According to the first aspect of the invention, a fuel tank is mounted on a main frame, an internal combustion engine is disposed below the fuel tank, and external air is guided from above the main frame to the internal combustion engine via an external air introduction pipe. In the motorcycle made as described above, a concave portion having a front side opened in the fuel tank is formed,
A tank chamber for storing fuel is formed at least above and behind the concave portion, and a lower surface of a front end of the tank chamber secures an intake passage substantially equivalent to the outside air introduction pipe as a distance away from an upper end of the main frame to an upper side. So that it is supported by the main frame by a mounting stay at an upper position,
An air cleaner is arranged in the recess, and a cover is provided separately on the front side of the fuel tank, and an outer surface thereof is flush with an outer surface of the fuel tank, and the cover covers the mounting stay, It has a shape that covers at least the front of the concave portion whose front side is open, and further has a hole formed in the cover at a position facing the intake passage so that outside air is guided to the hole through the outside air introduction pipe. An intake air introduction device for a motorcycle, wherein outside air introduced through the hole is guided from the intake passage to the air cleaner. ].

According to the first aspect of the present invention, the fuel tank has a recess with a front side opened, and at least above and behind the recess, a tank chamber for storing fuel is formed.
Leakage of intake noise to the outside can be reduced.

In addition, the lower surface of the front end of the tank chamber can be supported on the main frame while securing an intake passage substantially equivalent to the outside air introduction pipe by the mounting stay, and it is mounted on the main frame while securing the intake introduction passage. Although the stay is large, the cover covers the mounting stay, so that the appearance is not impaired.

Further, since the cover covers at least the front of the concave portion whose front side is open, the escape of the introduced air to the outside is reduced, and the suction efficiency is improved.

In addition, the outside air introduction pipe is introduced into the air cleaner without penetrating the tank chamber of the fuel tank, and the air cleaner is disposed in a concave portion having an open front side of the fuel tank, so that the volume of the air cleaner according to the internal combustion engine is easily secured. Can be.

In addition, the outside air guided through the outside air introduction pipe is separated from the fuel tank, and is guided to the recess through a hole provided in a cover whose outer surface is flush with the outer surface of the fuel tank. ,
Since the outside air introduction pipe does not penetrate the fuel tank, it is easy to manufacture a fuel tank that requires airtightness, and it is not necessary to secure the fuel sealing property as in the case where the outside air introduction pipe is penetrated into the conventional fuel tank. The appearance is good because the structure is simple and the surface is flush.

[Embodiment of the Invention] Next, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 to 3 are views showing a motorcycle to which the present invention is applied.

In the figure, reference numeral 1 denotes a motorcycle, a front wheel 5 is supported on a head pipe 3 of a frame 2 via a front fork 4, and a fuel tank 7 is mounted on left and right main frames 6 extending rearward from the head pipe 3. At the same time, the internal combustion engine 8 is suspended.

An air cleaner 9 and a carburetor 10 constituting an intake system of the internal combustion engine 8 are arranged on the front side of the fuel tank 7.

A rear frame 12 is attached to the rear end bracket 11 of the main frame 6 so as to face rearward.
The rear wheel 15 is supported via a rear arm 14 below the bracket 11.

A radiator 16 is provided in front of the internal combustion engine 8, and is covered with a cowling 17 from the front of the head pipe 3 to the side of the internal combustion engine 8.

A pair of outside air introduction pipes 18 is provided between the cowling 17 and the fuel tank 7, and an outside air introduction port 17a of the cowling 17 is provided.
Is introduced into an air cleaner 9 disposed on the front side of the fuel tank 7 via an outside air introduction pipe 18.

This fuel tank 7 is, as shown in FIGS.
Aluminum outer plate 19 and inner plate 20 are formed by welding. The inner tank 20 is formed in the fuel tank 7 with a concave portion 21 having a front side opened, thereby forming the air cleaner 9.
The space which accommodates is secured. Also, the fuel tank 7
A recess 21 having an open front side is formed at the top, and a tank chamber for containing fuel is formed at least above and behind the recess 21, so that leakage of intake noise to the outside can be reduced.

The air cleaner 9 is a concave part with the front side of the fuel tank 7 opened.
It is arranged in the shape of the concave portion 21 of the fuel tank 7 to secure a volume.

A projection 22 is formed on the fuel tank 7 by the inner plate 20, and a fuel pump 23 is mounted on the inner plate 20 via a mounting mechanism 24 and housed in the fuel tank 7.

The fuel pump 23 is connected to the fuel tank 7 via a hose 25.
The negative pressure cock 26 is connected to a negative pressure cock 26 provided outside the fuel hose, as shown in FIG. 4 and FIG.
Each carburetor 10 provided in the internal combustion engine 8 via 27
To supply fuel. The vacuum cock 26 has an intake passage downstream of the carburetor 10.
28 and a negative pressure hose 29. Internal combustion engine 8
When the intake passage 28 becomes negative pressure at the start of the operation, the negative pressure cock 26 is automatically operated to automatically supply fuel to the carburetor 10. The negative pressure cock 26 includes the fuel tank 7 and the carburetor 10
It is arranged in a small space with the obstacle, so that it does not interfere with obstacles. Further, since it is arranged in the small space, it automatically operates.

Also, the fuel hose 27 and the negative pressure hose 29 are bent in a U-shape as shown in FIG. 6, are connected with play, and are along the water pipe 30 of the cooling mechanism of the internal combustion engine 8.
During maintenance and inspection of the internal combustion engine 8, the fuel tank 7 can be lifted, and is not sandwiched between the fuel tank 7 and the carburetor 10.

At the front end of the fuel tank 7, as shown in FIG.
A reinforcing plate 31 is welded to the reinforcing plate 31, and a mounting bracket 32 is welded to the reinforcing plate 31. A mounting stay 33 is fastened and fixed to the mounting bracket 32 with a bolt 35 via a damper 34. Both ends 33a of the mounting stay 33 are fastened to a boss 6a formed on the front side of the main frame 6 via a bolt 36. It is fixed.

This mounting stay 33 has a cover 37 so that it cannot be seen from the outside.
The cover 37 is attached to the front side of the fuel tank 7. As shown in FIG. 8, this cover 37 is attached to the outer plate of the fuel tank 7 by attaching a damper 40 attached to the inside thereof.
As shown in FIG. 11, the hook 38 is inserted against the spring 39 against the inner plate 20 projecting forward from the front side 19, and when the hook 38 is rotated by a predetermined angle, the hook 38 can be locked with one touch.

Thus, the front end of the tank chamber of the fuel tank 7 is located at a position above the upper end of the main frame 6 by a predetermined distance.
Main frame 6 while securing the intake passage by 33
Can be supported. Moreover, when the tank front end is supported at a position near the upper end of the main frame 6,
The mounting stay 33 is also inconspicuous because it is small, but if the air intake passage is secured and supported by the main frame 6 as described above, the mounting stay 33 becomes large, but the cover 37 covers the mounting stay 33. The appearance is not impaired.

Further, the cover 37 is fixed to the inner plate 20 which is bent and rigid, so that it can be reliably supported and the cover 37
37 and the outer plate 19 of the fuel tank 7 are flush with each other, so that they have an integral shape and have a good appearance.

The cover 37 has a pair of holes through which the outside air introduction pipe 18 is inserted.
37a are formed. A hose 42 connected to the breather 41 of the fuel tank 7 is inserted through the cover 37,
The hose 42 is guided from the inside of the main frame 6 to the rear of the vehicle body, and discharges fuel that may leak from the breather 41 of the fuel tank 7 to the rear of the vehicle body.

A pair of brackets 43 are fixed to the rear end of the fuel tank 7 by welding, and the brackets 43 are inserted into rubber dampers 46 fixed to bolts 45 on cross members 44 provided on the rear end of the main frame 6. Further, a rubber damper 47 is applied to the bracket 43, and a bolt 48 is screwed to the bolt member 45, and is tightened and fixed together with the bottom plate 49 of the seat 13.

A hose 61 for discharging fuel overflowing from the cap 60 to the outside is provided in the fuel tank 7.
Numeral 61 penetrates a portion of the bracket 43 whose rigidity is increased by welding.

A central portion of the inner plate 20 of the fuel tank 7 is mounted on the main frame 6 via a rubber damper 50, and a mirror stay mounting portion 62 for supporting a mirror is provided on the front side of the main frame 6.
Is provided. By removing the mounting portion 62 of the mirror stay, the cover 37 provided on the fuel tank 7 can be further disposed closer to the head pipe 3 side, so that the air cleaner 9 can be further extended to the head pipe 3 side to reduce the volume. Can be increased.

In this way, the outside air introduction pipe 18 is fitted from the hole 37a formed in the cover 37, and the outside air is guided from the outside air introduction port 17a of the cowling 17 to the air cleaner 9.
The air cleaner 9 is disposed in a concave portion 21 which is open at the front side of the fuel tank 7, and the volume of the air cleaner 9 is increased.

In a commercial vehicle, when the motorcycle 1 travels, outside air is introduced from the outside air inlet 17a of the cowling 17 into the recess 21 opening the front side of the fuel tank 7 through the outside air introduction pipe 18, and the air in the recess 21 is opened. Is cooled and new air is supplied to the air cleaner 9. As described above, the air is introduced from the outside air introduction pipe 18 into the air cleaner 9, but since the air introduction portion is covered with the cover 37, the escape of the air to the outside is reduced, and the suction efficiency is improved.

On the other hand, the racer is provided with an induction disposed upstream of the air cleaner 9 to supply outside air to the outside air introduction pipe 18.
When the air supply is forcibly supplied to the air cleaner 9 via the internal combustion engine 8, the power of the internal combustion engine 8 is improved.

FIG. 12 shows a part of the air cleaner 9 in a concave portion 7a in which the front side of a fuel tank 7 arranged behind the main frame 6 is opened.
9a are connected to each other. The air cleaner 9 constitutes a cover according to the present invention, and a hole 9b is formed in the air cleaner 9 so that the outside air introduction pipe is directly connected to the air cleaner 9 to give a sense of unity between the air cleaner 9 and the fuel tank 7. In addition, it is easy to secure the volume for each.

[Effects of the Invention] As described above, according to the first aspect of the present invention, the fuel tank is formed with a concave portion having an open front side, and at least above and behind the concave portion, a tank chamber for storing fuel is formed. As a result, leakage of intake noise to the outside can be reduced.

The lower surface of the front end of the tank chamber is supported on the main frame by a mounting stay at an upper position so as to secure an intake passage substantially equal to the outside air introduction pipe as a distance upward from the upper end of the main frame. The mounting bracket can be supported on the main frame while securing the intake passage, and the mounting stay becomes large, but the cover covers the mounting stay, so that the appearance is not impaired .

Further, since the cover covers at least the front of the concave portion whose front side is open, the escape of the introduced air to the outside is reduced, and the suction efficiency is improved.

In addition, the outside air introduction pipe is introduced into the air cleaner without penetrating the tank chamber of the fuel tank, and the air cleaner is disposed in a concave portion having an open front side of the fuel tank, so that the volume of the air cleaner according to the internal combustion engine is easily secured. Can be.

In addition, the outside air guided through the outside air introduction pipe is separated from the fuel tank, and is guided to the recess through a hole provided in a cover whose outer surface is flush with the outer surface of the fuel tank. ,
Since the outside air introduction pipe does not penetrate the fuel tank, it is easy to manufacture a fuel tank that requires airtightness, and it is not necessary to secure the fuel sealing property as in the case where the outside air introduction pipe is penetrated into the conventional fuel tank. The appearance is good because the structure is simple and the surface is flush.

[Brief description of the drawings]

FIG. 1 is a side view of a motorcycle to which the present invention is applied, and FIG.
FIG. 3 is a plan view, FIG. 3 is a front view, FIG. 4 is a sectional view of the fuel tank, FIG. 5 is a plan view, FIG. 6 is a view of FIG. 7 is a view of FIG. 4 as viewed from the direction of arrow B, FIG. 8 is a sectional view of FIG. 5 taken along line VIII-VIII, FIG. 9 is a sectional view of FIG. 5 taken along line IX-IX, and FIG. 11 is a sectional view taken along line XI-XI in FIG. 5, and FIG. 12 is a side view of another embodiment. In the figure, reference numeral 1 is a motorcycle, 6 is a main frame, 7 is a fuel tank, 8 is an internal combustion engine, 9 is an air cleaner, 10 is a carburetor, 19 is an outer plate, 20 is an inner plate, 7a and 21 are recesses, 18 is It is an outside air introduction pipe.

Continuation of the front page (56) References JP-A-63-184582 (JP, A) JP-A-61-275076 (JP, A) JP-A-62-83292 (JP, A) Real opening JP-A-63-158488 (JP, A) , U) JP-A-61-117082 (JP, U) JP-B-62-29273 (JP, B2) JP-B-58-27153 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB Name) B62J 39/00 B62J 35/00 B62M 7/02

Claims (1)

(57) [Claims] 1. A fuel tank is mounted on a main frame, and an internal combustion engine is arranged below the fuel tank, and external air is guided from above the main frame to the internal combustion engine via an external air introduction pipe. In the motorcycle, a concave portion having a front side opened in the fuel tank is formed, and at least above and behind the concave portion, a tank chamber for storing fuel is formed, and a lower surface of a front end of the tank chamber extends upward from an upper end of the main frame. The main frame is supported by the mounting frame at an upper position so as to secure an intake passage substantially equivalent to the outside air introduction pipe as a separation distance to the outside air introduction pipe, and an air cleaner is disposed in the recess. A cover is provided separately and the outer surface of which is flush with the outer surface of the fuel tank. The cover covers the mounting stay and has a front side. It has a shape that covers at least the front of the released concave portion, and further has a hole formed in the cover at a position facing the intake passage, and guides outside air to the hole through the outside air introduction pipe, An intake air introduction device for a motorcycle, wherein outside air introduced from the hole is guided from the intake passage to the air cleaner.