JPH02216381A - Intake device for motorcycle - Google Patents

Abstract

PURPOSE:To obtain a required cooling effect introducing the outside air in the vicinity of a carburetor by arranging a suction port of a suction passage in an air cleaner in the vicinity of the carburetor between the air cleaner and an engine. CONSTITUTION:Ram air is introduced from an introducing port passing through a duct 23 thereafter supplied to space surrounded by a car body frame, bottom wall of a fuel tank and its side wall. Supplied air is guided in the vicinity of an opening of a suction duct 19 by a guide wall 17c of an air cleaner 15, further the air, after it passes through lower and upper side passages 17b, 16b, is filtered by an element 18 and sucked to a carburetor 14. Here the air cleaner 15 and the suction duct 19 are arranged respectively in the above described space. And the suction duct 19 is opened toward the guide wall 17c of the air cleaner 15 in the vicinity of the carburetor 14. Thus introducing the ram air in the vicinity of the carburetor 14, a required cooling effect is obtained.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an intake system for a motorcycle, and in particular, an air cleaner is disposed in a space surrounded by a pair of left and right main pipes, a fuel tank, etc. This invention relates to an improvement in the suction passage of an air cleaner in which the cooling effect of the vaporizer layer can be obtained when the vaporizer is located below the vaporizer.

(Prior Art) The intake VT2 of a motorcycle generally has a configuration in which a carburetor is connected to the rear wall of the cylinder head and an air cleaner is connected to the carburetor. It is desirable that the passage be opened in a place where it is not affected by dynamic pressure caused by the wind while the vehicle is running, and where it is difficult for rainwater to enter.

By the way, in the intake system of a motorcycle, an air cleaner is installed in a space surrounded by a pair of left and right main pipes connected to a head pipe, and a fuel tank arranged to cover between the two main pipes. There is a structure in which a carburetor is disposed between the air cleaner and the cylinder. In such an intake device, as a structure for arranging the suction passage in consideration of the problems of dynamic pressure, rainwater, etc., there has conventionally been a structure in which the suction passage is extended near the head pipe and opened at that part (for example, Japanese Patent Publication No. 51-31435
(see publication).

When the suction passage is opened near the head pipe as in the above-mentioned intake device, it is possible to prevent water from entering by 2 m due to dynamic pressure.

[Problem that the invention seeks to solve]

By the way, in recent years, there have been many cases in which the main vibe has a vertical cross section, and in this case, an air cleaner is installed in the space surrounded by the pair of left and right main pipes and the fuel tank, etc. When a carburetor is disposed between the rear wall of the cylinder and the cylinder, hot air from the engine is absorbed by the air cleaner, especially during low-speed driving or idling in the summer.

Remains near the vaporizer. Therefore, if the fuel is at the extreme end, bubbles are generated in the fuel in the carburetor, resulting in the problem of so-called Bercoley silane.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and is capable of preventing the influence of dynamic pressure and the infiltration of rainwater, etc., and preventing the occurrence of barcole silane. The purpose is to provide equipment.

[Means for solving problems]

The present invention provides an automatic vehicle in which a fuel tank, etc. is disposed to cover between a pair of left and right main pipes having a vertically long cross-sectional shape connected to a hend pipe, and an engine is disposed below the fuel tank, etc. In an intake system for a two-wheeled vehicle, a carburetor and an air cleaner are sequentially connected to the engine, and the air cleaner is located in a space surrounded by the pair of left and right main vibes, a fuel tank, etc., and a suction passage to the air cleaner is provided. is connected to the front wall of the air cleaner and extends downward, and the suction port of the suction passage is located near the carburetor.

Here, the term "near the carburetor" as used in the present invention means within an area where air around the carburetor can be sucked during idling or the like.

[Effect]

According to the intake device according to the present invention, since the suction port of the suction passage is located near the carburetor, at extremely low speeds or when idling, air near the carburetor is sucked in, and the intake amount increases. A corresponding amount of outside air is now introduced around this carburetor. Therefore, the rise in the ambient temperature near the carburetor is suppressed to that extent, and as a result, bubbles are not generated in the fuel in the carburetor even in the summer (this problem with Barcoley Silane can be avoided).

Furthermore, in the present invention, the suction passage of the air cleaner extends downward along the front wall of the air cleaner and opens near the carburetor, so that the suction port is surrounded by the above-mentioned main vibrator, fuel tank, etc. Since the engine is located in a space with a high temperature, intake noise is suppressed from being emitted outward, and the influence of dynamic pressure caused by the wind while driving and the intrusion of rainwater and the like are also suppressed.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 to 5 are diagrams for explaining an intake system for a motorcycle according to an embodiment of the present invention.

In the figure, reference numeral 1 denotes a motorcycle to which this embodiment is applied, and a body frame 2 of the motorcycle 1 has a head pipe 2a extending diagonally downward to the rear of the vehicle.

The structure is such that a pair of right main vibes 2b, 2b are connected, a rear arm bracket 2c is connected to the rear end of each main vibe 2b, and the left and right rear arm brackets 2c are connected to each other by a cross vibe (not shown). There is. The main vibe 2b is a rectangular cylinder made by welding a pair of U-shaped aluminum plates together.
Its cross-sectional shape is a vertically elongated rectangle on the head pipe 2a side, and the left and right main vibes 2b surround both sides of the upper part of the vehicle.

Further, a front fork 4, which pivotally supports the front wheel 3 at its lower end, is supported by the head pipe 2a so as to be steerable to the left or right, and a steering handle 5 is fixed to the upper end of the front fork 4. There is. Further, the front end of the rear arm 7, which pivotally supports the rear wheel 6 at its rear end, is pivotably supported by the rear arm bracket 2C so as to be swingable up and down.

A fuel tank 8 is mounted on the left and right main vibes 2b of the vehicle body frame 2 so as to cover between both pipes. The front half of the bottom wall 8a of the fuel tank 8 is raised upward, and an air cleaner arrangement space A is formed by the bottom wall 8a and the left and right side walls 8b. Further, a saddle-shaped seat 9 is mounted behind the fuel tank 8, and a lower portion of the seat 9 is surrounded by a carrier cover 10.

This rear cover 10 covers the upper part of the rear wheel 6.

An engine unit 11 is suspended and supported below the vehicle body frame 2. This engine unit 11 is a water-cooled 4-cycle parallel 4-cylinder type, and has a cylinder body 13a on the upper wall of a crankcase 12 that houses a crankshaft and a transmission.

The engine body 13, which is made up of a stacked cylinder head 13b and head cover 13c, is connected in a forward-leaning manner at approximately 45 degrees. Further, the left and right sides of the engine unit 11 and the front part of the vehicle are covered with a cowling 21,
This cowling 21 includes a screen 21a, a front cover 21b that covers the front side of the front fork 4, and a pair of side covers 21 that cover the left and right sides of the engine unit 11.
It is composed of c. Traveling air introduction ports 22 are formed on the left and right sides of the front cover 21b, and the front end of an introduction duct 23 is connected to the inside of the introduction ports 22. A rear end portion of the introduction duct 23 passes through the front portion of the main vibe 2b and opens into the air cleaner arrangement space A.

An independent carburetor 14 for each cylinder is connected to the rear wall of the cylinder head 13b via a carburetor joint 14a. This carburetor 14 is a so-called downdraft type carburetor in which the air flow is directed from top to bottom.
An air cleaner 15 is connected via 4b. This air cleaner 15 is located within the air cleaner arrangement space A! However, its top wall, rear wall 2, and left and right side walls are covered with the bottom wall 13a, side wall 8b, and left and right main pipes 2b of the fuel tank 8 mentioned above.

The air cleaner 15 has a structure in which an element is disposed inside a cleaner case having a vertically divided structure consisting of an upper case 16 and a lower case 17. The protrusion 17h is fixed to the main pipe 2b via a grommet 21d. Further, -@20a of an air release hose 20 for introducing atmospheric pressure into the float chamber 14d of the vaporizer 14 is connected to the vicinity of the suction port 14c of the vaporizer 14. This air release hose 20 is made of a rubber tube.
Lower case 17 and upper case 1 of the air cleaner 15
The air cleaner 15 extends upward along the rear walls 17e and 16c of the air cleaner 15, and is fixed by a bracket portion 17g formed on the lower case 17, and is further bent downward near the upper end of the air cleaner 15, with its tip attached to the lower case 17. It is fixed by a formed bracket 17f.

The element 1B of the air cleaner 15 is formed into a rectangular plate shape, and the periphery of its holding bracket 18a is held between the flanges of the upper and lower cases 16 and 17. A lower passage 16b is integrally formed in the front wall 16a of the upper case 16 so as to extend downward, and the upper passage 16b is connected to a lower passage 17b integrally formed in the front wall 17a of the lower case 17. It is connected in communication. The lower half of this front wall 17a is retracted rearward to form a guide wall 17C, and a suction duct 19 is connected to the lower passage 17b. This suction duct 19 extends toward the guide wall 17C side along the lower surface of the retreating wall of the front side wall 17a, and the lower case 1
7 is fixed with bolts. Further, the guide duct 19 opens so as to oppose the guide wall 17c, and the opening is located above the carburetor 14.

This causes the air near the carburetor 14 to flow into the guide wall 17c.
It is designed to be guided to the opening of the duct 19 by the tucking.

Next, the effects of this embodiment will be explained.

According to the intake system of this embodiment, while driving, the running wind is introduced from the inlet 22, passes through the inlet duct 23, passes through the above-mentioned left and right main pipes 2b, the bottom wall 8a of the fuel tank 8,
It is introduced into the space A surrounded by the side wall 8b. This introduced air is guided near the opening of the suction duct 19 by the guide wall 17c of the air cleaner 15, sucked in from the opening, passes through the lower and upper passages 17b and 16b, is filtered by the element 18, and then sucked into the vaporizer 14. be done.

Furthermore, during extremely low speed running or idling, air near the carburetor 4 is sucked into the engine through the suction duct 19 through the air cleaner 15. Therefore,
An amount of outside air corresponding to the amount of air sucked into the engine is introduced into the vicinity of the carburetor 14.

As mentioned above, connect the air cleaner to the main pipe.

If the carburetor is placed in a space surrounded by a fuel tank, etc., and the carburetor is placed below it, hot air from the engine stays in the vaporizer layer during idling, and Percolation silane is likely to occur. There's a problem. On the other hand, in this embodiment, since the suction duct 19 of the air cleaner 15 is opened near the carburetor 14, the air near the carburetor 14 is sucked into the suction duct 19, and the amount of outside air is Since it is introduced near the vaporizer 14, the vaporizer 1
Hot air does not stay around 4, and a cooling effect can be obtained. Therefore, the generation of Barcolay silane can be avoided.

In this case, since the intake air temperature increases, there is a concern that the engine's charging efficiency and eventually the output will decrease, but since the intake air temperature only increases when driving at low speed or when idling, the output decreases. is not a problem.

Further, since the suction duct 19 of this embodiment is located in a space surrounded by the main pipe 2b and the fuel tank 8, the emission of intake noise to the outside is suppressed, which is advantageous in terms of noise countermeasures. In addition, since the suction passages 16b, 17b and the suction duct 19 are formed so as to go around the front wall of the air cleaner 15, the passage length becomes longer and the fundamental frequency of intake noise becomes smaller, which is also advantageous in terms of noise countermeasures. be.

Furthermore, the suction duct 19 is connected to the air cleaner 1.
5 guide! Since it is opened toward 17C, dynamic pressure caused by the running wind hardly acts on this suction duct 19 while the vehicle is running, and it is possible to avoid the problem of intake pulsation and prevent the infiltration of rainwater and the like.

Further, in this embodiment, the float chamber 14d of the vaporizer 14 is
The air bleed hose 20 that introduces atmospheric pressure is opened between the rear wall of the air cleaner 15 and the bottom wall 8b of the fuel tank 8, and is fixed to this area, thereby preventing the influence of dynamic pressure and the intrusion of rainwater, etc. This problem can be avoided, and since there is a sufficient head difference, even if the vaporized fuel from the vaporizer 14 is liquefied in the hose 20, it is returned to the float chamber 14a, and the hose 2
It does not drip from 0, and for example, the fuel tank 8
When installing the air vent hose 20, the bottom wall 8a of the fuel tank 8 hardly interferes with the air vent hose 20, and therefore the installation work can be facilitated. ) air cleaner 15
However, the suction passage of the present invention does not necessarily have to be opened in this way, and the point is that the suction passage of the present invention is opened so as to oppose the guide wall 17c of the carburetor. It may be opened near the vaporizer.

〔Effect of the invention〕

As described above, according to the intake system for a motorcycle according to the present invention, the intake port of the intake passage of the air cleaner is located near the carburetor disposed between the air cleaner and the engine. By sucking in the air near the vaporizer, etc., it is possible to introduce outside air into the vicinity of the vaporizer to achieve a cooling effect, which has the effect of preventing an abnormal rise in ambient temperature and avoiding Barcoley silane.

[Brief explanation of the drawing]

1 to 5 are diagrams for explaining an intake system for a motorcycle according to an embodiment of the present invention, in which FIG. 1 is a cross-sectional side view thereof, FIG. 2 is a rear view of an air cleaner, and FIG. 4 is a left side view of the motorcycle to which this embodiment is applied, and FIG. 5 is a plan view thereof. In the figure, 1 is a motorcycle, 2a is a head pipe, 2
b is a main pipe, 8 is a fuel tank, 13b is a cylinder head (engine), 14 is a carburetor, 15 is an air cleaner, 16a and 17a are the front wall of the air cleaner, and 19 is a suction duct (suction passage). Patent Applicant Yamaha Motor Co., Ltd. Agent Patent Attorney Tsutomu Shimoichi Figure 3

Claims (1)

[Claims] (1) A pair of left and right main pipes having a vertically long cross-sectional shape are connected to the head pipe, and a fuel tank or tank cover (hereinafter referred to as fuel tank, etc.) covers between the left and right main pipes. In an intake system for a motorcycle in which an engine is disposed below the fuel tank, etc., a carburetor is connected to the engine, and an air cleaner is connected to the carburetor, and the air cleaner is connected to the left and right It is located in a space surrounded by a pair of main pipes and a fuel tank, etc., and a suction passage to the air cleaner is connected to the front wall of the air cleaner and extends downward, and the suction port of the suction passage is connected to the vaporizer. An intake device for a motorcycle, characterized in that the intake device is located near a container.