JP3102257B2 - Motorcycle air intake system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art As shown in FIG. 9, an air intake device for an engine of a motorcycle includes an air cleaner d located behind and above an engine c supported by a down tube b extending downward from a steering head pipe a. And a carburetor e for introducing air (fresh air) purified by the air cleaner d and supplying an air-fuel mixture to a cylinder of the engine c.

As shown in FIG. 10, an air cleaner d is an air cleaner case (hereinafter simply referred to as a case).
f, and a filter g housed in the rear part of the case f, and an outlet tube h communicating between the inside of the carburetor body of the carburetor e and the inside of the case f is provided at the center in the vertical direction of the front wall f1 of the case f. It is inserted. Further, a breather chamber i formed by projecting the front wall f1 forward is provided below the front wall f1 of the case f. The breather chamber i is connected to the end j1 of a breather tube j for releasing an increase in the internal pressure in the crankcase of the engine c, and separates gas and liquid from the inside of the crankcase in the chamber. (Separate oil and gas). Conventionally, an air vent hose chamber k is provided at an upper portion and a front end of the case f, and an air vent hose communicating with the inside of a float chamber (float chamber) of the carburetor e is provided at a grip portion k1 of the air vent hose chamber k. The air vent hose keeps the internal pressure of the float chamber at atmospheric pressure.

[0004] Further, like another conventional motorcycle intake device shown in FIG. 11, an air vent hose m is piped to the rear side of the air cleaner d1 along the upper wall of the air cleaner d1. In some cases, the open end m1 is located in the space between the air cleaner d1 and the battery n.

[0005]

However, in the conventional motorcycle intake device, the air vent hose chamber k is located above the air cleaner d, so that the air vent hose chamber is located between the carburetor body and the air vent hose chamber k. When piping, the end of the air vent hose on the open side (the end on the air vent hose chamber k side)
Is turned upward, so that water easily enters the air vent hose from the end, and there is a possibility that water may accumulate in the float chamber.

Further, due to the arrangement of the air vent hose piping and the carburetor e, the air vent hose chamber k is connected to the front wall f.
In order to provide the air vent hose chamber k, it is necessary to reduce the capacity of the air cleaner d or increase the size of the entire air cleaner d to provide the air vent hose chamber k. Further, since the end of the air vent hose gripped by the grip portion k1 of the air vent hose chamber k faces rearward, the air vent hose cannot be formed into a straight shape. Therefore, a molded hose is usually used as an air vent hose. Had to be used.

[0007] On the other hand, even in the above-mentioned other conventional suction device, a long hose is required as the air vent hose m, which increases the cost. There is a possibility that the vicinity of the portion m1 becomes negative pressure due to the wind flowing around the portion, and the liquid level of the fuel in the float chamber becomes unstable.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems in the conventional motorcycle air intake system, and an object of the present invention is to ensure effective use of motorcycle space by utilizing wasteful space. It is another object of the present invention to provide a motorcycle air intake device that improves the performance of an engine, particularly in the output aspect.

[0009]

The present invention has the following configuration to achieve the above object. That is, the present invention relates to an air cleaner disposed above and slightly behind a crankcase of an engine, and introducing an air-fuel mixture from the air cleaner to an upper portion of a front wall of the air cleaner and introducing fresh air from the air cleaner. In a motorcycle intake device provided with a carburetor for supplying to a cylinder,
A lower portion of the front wall of the air cleaner is adjacent to a breather chamber communicating with the crankcase via a breather tube, and an air vent hose chamber communicating with the float chamber of the carburetor via an air vent hose. An intake device for a motorcycle characterized by being protruded forward.

[0010]

According to the present invention, the air vent hose chamber comprises:
In the lower part of the front wall of the air cleaner, since it is adjacent to the breather chamber and protrudes forward,
The air vent hose chamber is located in the space between the carburetor and the crankcase together with the breather chamber. Therefore, when the air vent hose is provided in the air cleaner, the space can be used to effectively use the space of the motorcycle.

Further, since the air vent hose chamber is located at a position lower than the carburetor, when piping the air vent hose, the end of the air vent hose (the end on the side of the air vent hose chamber) does not need to be directed upward and is always directed downward. Since water can be piped in a closed state, water does not intrude from the end.

Since the air vent hose chamber protrudes forward from the front wall of the air cleaner, one end of the air vent hose attached to the carburetor body is connected to the upper wall of the air vent hose chamber. Since the air vent hose can be attached, the air vent hose can have a straight shape. Therefore, it is not always necessary to use a molded hose as the air vent hose.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing a configuration around an intake device of a motorcycle according to the embodiment, FIG. 2 is a side view of an air cleaner according to the embodiment, and FIG. 3 is a front view of the air cleaner according to the embodiment. FIG. 4 is a side view of the air cleaner case according to the present embodiment. FIG. 5 is a cross-sectional view taken along line VV of FIG.
FIG. 7 is a sectional view taken along the line A of FIG. 4, FIG. 7 is a sectional view taken along the line VII-VII of FIG. 3, and FIG. 8 is a sectional view taken along the line VIII-VIII of FIG.

The intake device for a motorcycle according to the present embodiment comprises:
As shown in FIG. 1, an air cleaner 6 disposed above and slightly behind the crankcase 4 of the four-stroke engine 2, and a new air cleaner 6 opposed to the upper part of the front wall 8 of the air cleaner 6. And a carburetor 12 for introducing air into the cylinder portion 10 to supply the air-fuel mixture into the cylinder portion 10. In the following, in the present embodiment, the front refers to the vehicle traveling direction, the rear refers to the opposite direction to the vehicle traveling direction, the left refers to the traveling direction and the left in the vehicle width direction, and the right refers to the right. Refers to the right side in the vehicle width direction in the traveling direction.

The motorcycle according to this embodiment has an engine 2 which extends rearward from a steering head pipe (not shown).
And a pair of left and right frames 22 (shown on the left side in the figure) extending obliquely downward to the rear of the engine 2 and extending rearward from a substantially central portion in the longitudinal direction of the frame 22. A set of seat rails 24 (shown on the left side in FIG. 1), a seat 26 mounted and fixed on the seat rails 24, and a substantially saddle-shaped fuel tank 28 located on the front side of the seat 26 Is provided. In addition, what is indicated by reference numeral 30 behind the air cleaner 6 is a battery.

As shown in FIGS. 2 and 3, the air cleaner 6 has the front wall 8 and has a hollow air cleaner case (the shape of which becomes smaller toward the rear from the front wall 8). Hereinafter, simply referred to as a case) 32,
A substantially cylindrical filter portion 36 fitted into the opening at the rear of the case 32 and fixed with screws 34 and the like; a box-shaped fastening portion 38 provided at the rear and side of the case 32 and opened rearward; It has a pair of left and right outlet tubes 40 fitted into the opening in the substantially central portion in the vertical direction of the front wall 8. A cushion member 42 is attached from the front end of the upper surface of the case 32 to the upper part of the front end of the right side. As shown in FIG. 1, the air cleaner 6 includes a bracket 2 provided on a seat rail 24.
4a, is fixed by a screw member such as a bolt and a nut via a fastening portion 38.
The fuel tank 28 is located in an inverted U-shaped space formed by the saddle-shaped lower surface.

As shown in FIGS. 3 and 4, the case 32 has a pair of right and left case members having a substantially U-shaped vertical cross section opposed to each other, and their respective edges are fitted and welded. On the outer peripheral surface of the case 32, an annular fitting welded portion 44 extending slightly in the front-rear direction is formed so as to protrude slightly. Also, in the lower part of the front wall 8 of the case 32,
Through the breather tube 14, the crankcase 4
Breather chamber 16 communicating with the inside and air vent hose 1
An air vent hose chamber 20 communicating with the inside of the float chamber of the carburetor 12 through the air inlet 8 protrudes forward and forward. An outlet pipe 48 is provided at the front end and the lower end of the left side wall of the case 32 so as to project leftward and into which a drain pipe 46 is fitted.

As shown in FIGS. 3, 4 and 5 (shown by gradation in FIG. 3), the breather chamber 16 projects from a substantially central portion of the lower portion of the front wall 8 of the case 32 and is integrally formed with the case 32. It was done. Further, a breather chamber inlet pipe 16e is provided on the right side wall 16R of the breather chamber 16 at a substantially central position thereof and protrudes rightward.
Further, as shown in FIG. 5 and FIG.
16k for partitioning the space inside 6 and the air cleaner chamber
Is formed continuously with the front wall 8 and
At the lower end of 6k, there is provided a gap 16h communicating the space in the breather chamber 16 with the air cleaner chamber.

As shown in FIG. 3, the breather tube 1 is connected to the breather chamber inlet pipe 16e by a clip 50.
4 has one end attached. The other end of the breather tube 14 is fitted to a union pipe (see FIG. 1) 52 fixed to the upper wall of the crankcase 4, and connects the inside of the crankcase 4 and the inside of the breather chamber 16. Therefore, the fluid containing gas and oil from inside the crankcase 4 is sent into the breather chamber 16 via the breather tube 14 and is separated into gas and liquid in the chamber. The separated gas passes through the gap 16h of the breather chamber 16 and then returns to the carburetor.

On the other hand, as shown in FIGS. 2 and 3, the air vent hose chamber 20 has a substantially inverted L-shaped wall portion 20 forming the upper wall and the front wall of the air vent hose chamber 20.
L, a space surrounded by the front wall 8 of the case 32 and the left side wall 16L of the breather chamber 16, and the lower and left sides thereof are open. That is, the air vent hose chamber 20 is not opened forward,
The end of 8 is hardly affected by the traveling wind.

As shown in FIG. 6, the upper wall of the wall portion 20L is provided with a notch 20k opened to the left. The notch 20k has a circular hole 20k1 formed substantially at the center of the upper wall, and a circular hole 20k1.
And an open portion 20k2 which is open to the left. One end of the air vent hose 18 fits into the circular hole 20k1, and when the one end is fitted, the air vent hose 18 is fitted into the opening 20k2 from the left side of the notch 20k.

The outlet pipe 48 is provided on the left side wall 16L of the breather chamber 16 behind the partition 16k, and is located at the lowermost part of the air cleaner 32 as shown in FIG. At the same time as the water is drained to the outside, the oil for the oil flowing from the breather chamber 16 through the gap 16h is also discharged. 2 and 3
As shown in FIG. 7, the drain pipe 46 has one end attached to the outlet pipe 48 by a clip 54, and the other end fitted with a drain stopper 46 a as a stopper and fixed by a clip 56. Therefore,
In the air cleaner 6, the drainage from the air cleaner chamber and the oil content from the breather chamber 16 are simultaneously performed by removing the drain stopper 46a from the drain pipe 46.

According to the intake device for a motorcycle of the present embodiment having the above-described configuration, the air vent hose chamber 20 is
Since the lower part of the front wall 8 of the air cleaner 6 is adjacent to the left side of the breather chamber 16 and both chambers are projected forward, the air vent hose chamber 20 is provided together with the breather chamber 16 and the carburetor 12 and the crankcase 4. And will be located in the space between them. Therefore, the space between the carburetor 12 and the crankcase 4, which has been conventionally wasted space, can be effectively used, and the air vent hose chamber 20 can be provided in the air cleaner 6 by the above configuration. Can be effectively used. By effectively utilizing this space, the capacity of the air cleaner 6 can be made larger than before by the amount by which the air vent hose chamber 20 projects forward.
It is possible to improve the performance of the engine 2 particularly on the output side.

Further, since the air vent hose chamber 20 is located lower than the carburetor 12, when piping the air vent hose 18, the end of the air vent hose 18 (the air vent hose chamber 20 side) does not need to be directed upward, and is always lowered. , And water does not enter from the end.

Further, the other end of the air vent hose 18 having one end attached to the carburetor body can be attached to the upper wall of the wall 20L of the air vent hose chamber 20, so that the air vent hose 18 has a straight shape. It can be. Therefore, it is not always necessary to use a molded hose as the air vent hose 18, and the cost can be reduced.

The present embodiment is a preferred embodiment of the present invention, and the technical scope of the present invention is not limited to this embodiment. For example, the intake device of the present invention is not limited to the intake device of a motorcycle having a four-cycle engine 2, but is also applicable to the intake device of a two-cycle engine. In this case, the breather tube 14 serves mainly to prevent an increase in internal pressure due to a temperature change in the engine. Further, in the present embodiment, the breather chamber 16 and the air vent hose chamber 20 are formed integrally with the case 32, but the present invention is not limited to this, and may be welded to the front wall 8 of the case 32. It may be provided separately. Further, the amounts by which the breather chamber 16 and the air vent hose chamber 20 protrude forward are set to be larger than the amounts in the present embodiment, and the breather chamber 16
The air vent hose chamber 20 can be further widened, or the capacity of the air cleaner chamber can be further increased. Further, in the intake device for a motorcycle according to the present embodiment, even if only the air vent hose chamber 20 is protruded below the front wall 8, the useless space can be effectively used. However, the above-described effects such as effective use of the space of the motorcycle and improvement of the output of the engine 2 can be obtained.

[0027]

As described above, according to the motorcycle air intake apparatus of the present invention, it is possible to use the wasteful space to effectively use the space of the motorcycle and to improve the performance of the engine. Can be. Further, it is possible to prevent water from entering the float chamber of the carburetor, and it is not necessary to use a molded hose for the air vent hose, so that the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a side view showing a configuration around an intake device of a motorcycle according to an embodiment.

FIG. 2 is a side view of the air cleaner according to the embodiment.

FIG. 3 is a front view of the air cleaner according to the embodiment.

FIG. 4 is a side view of the air cleaner case according to the embodiment.

FIG. 5 is a sectional view taken along line VV of FIG. 4;

FIG. 6 is a view taken in the direction of arrow A in FIG. 4;

FIG. 7 is a sectional view taken along line VII-VII of FIG. 3;

8 is a sectional view taken along line VIII-VIII in FIG.

FIG. 9 is a side view showing the entire configuration of the motorcycle.

FIG. 10 is a partial cross-sectional view of an air cleaner according to a conventional motorcycle intake device.

FIG. 11 is a side view showing an intake device of another conventional motorcycle.

[Explanation of symbols]

 2 Engine 4 Crankcase 6 Air cleaner 8 Front wall of air cleaner 10 Cylinder section 12 Carburetor 14 Breather tube 16 Breather chamber 18 Air vent hose 20 Air vent hose chamber

Continuation of front page (56) References JP-A-4-254280 (JP, A) JP-A-2-200592 (JP, A) JP-A-63-53193 (JP, A) JP-A-59-206609 (JP) JP-A-2-20987 (JP, A) JP-A-5-172013 (JP, A) JP-A-2-145592 (JP, U) JP-A 64-35196 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B62M 7/02 B62J 39/00

Claims (1)

(57) [Claims] 1. An air cleaner disposed above and slightly behind a crankcase of an engine, and fresh air is introduced from the air cleaner to an upper part of a front wall of the air cleaner so that the air-fuel mixture is supplied to the engine. A motorcycle carburetor for supplying a cylinder with a carburetor, a lower part of the front wall of an air cleaner, a breather chamber communicated with the crankcase through a breather tube, and an air vent hose. An intake device for a motorcycle, characterized in that an air vent hose chamber communicating with a float chamber of a carburetor is adjacently and protruded forward.