JPH02296589A - Intake device for motorcycle - Google Patents

Abstract

PURPOSE:To increase the capacity of an air cleaner without increasing the length of a connection duct between the air cleaner and a fuel supply device by installing the air cleaner in a relatively large space under an engine and near the fuel supply device, and leading an intake duct above the engine. CONSTITUTION:Intake openings 11b are formed between upper and lower cylinder bodies 12 and 12 viewed from the side of the front walls of right and left crank chambers 11a of a crankcase 11 in the engine unit 10 of a motorcycle 1. In addition, an intake tube part 11c is so integrated with each intake opening 11b as to be extended approximately horizontally. A delivery port 20b as the downstream side opening of a carburetor (fuel supply device) 20 is connected to each intake tube part 11c via a carburetor joint 19. Also, an air cleaner 21 is provided under the engine unit 10, and an intake duct 27 is extended vertically upward between right and left rear arm brackets 2c and 2c for introducing the outside air to the air cleaner 21, and made open to the inside of a tank cover 7.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an intake device for supplying clean air filtered by an air cleaner to the engine of a motorcycle, particularly when a front intake/back exhaust system is adopted. The present invention relates to an improvement in the arrangement structure of the air cleaner.

[Conventional technology]

Some recent motorcycles have a so-called front intake, rear exhaust system in which a carburetor is connected to the front side of the engine and an exhaust pipe is connected to the rear side of the engine. This type of motorcycle was developed for competition use, which involves running at high speed within a predetermined course, and the intake position of this competition motorcycle was designed to reduce intake resistance as much as possible to improve output. , which is configured to suck in outside air directly without providing an air cleaner (for example, Japanese Patent Application No. 1688-1988)
(See No. 15).

[Problem that the invention seeks to solve]

By the way, in order to employ the above-mentioned front intake/rear exhaust system in a commercially available motorcycle for use on public roads, it is necessary to supply the engine with clean air filtered by an air cleaner in order to ensure the durability of the engine. In this case, it is necessary to develop an appropriate intake system according to the special structure of connecting the fuel supply system to the front side of the engine. For example, depending on the placement position of the air cleaner, the air cleaner capacity may be insufficient, or the air cleaner and fuel There is a concern that the connecting duct with the supply device may become long or that rainwater or the like may enter the air cleaner.

Therefore, in view of the above-mentioned situation, the present invention provides a front air intake system for commercially available vehicles.
It is an object of the present invention to provide an intake system for a motorcycle that can secure sufficient air cleaner capacity without the need for long connecting ducts between the air cleaner and fuel supply system when adopting a rear exhaust system, and that can prevent the intrusion of rainwater, etc. The purpose is

[Means for solving problems]

The present invention provides an intake device for supplying clean air to the engine in a motorcycle having a fuel supply device connected to the front side of the engine and an exhaust pipe connected to the rear side, the air cleaner being disposed below the engine. At the same time, it is characterized in that an intake duct connected to the fuel supply device and introducing outside air into the air cleaner is led out above the engine.

Here, the fuel supply device of the present invention includes both a normal carburetor and a fuel injection device in which a fuel injection valve and a throttle valve are arranged in a venturi pipe.

[Effect]

According to the intake system of the present invention, since the air cleaner is arranged in a relatively wide space below the engine and close to the carburetor, sufficient air cleaner capacity can be secured.
Further, the connecting duct with the fuel supply device can also be shortened.

Further, since the intake duct for introducing outside air into the air cleaner is led out to a high place above the engine and opened at the high place, it is possible to prevent rainwater etc. from entering the air cleaner.

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

FIGS. 1 and 2 are diagrams for explaining a motorcycle according to an embodiment of the present invention.

In the figure, l is the motorcycle of this embodiment, and the body frame 2 of this vehicle extends from the head pipe 2a at the front end diagonally downward to the rear of the vehicle body. A rear arm bracket 2C is integrally formed at the rear end of a pair of main frames 2b (when facing forward), and the two brackets 2c are connected to each other by a cross pipe. 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 left and right, and a left-9-right split steering handle 4a is fixed to the upper end of the front fork 4. has been done.

Further, a rear arm 6, which pivotally supports the rear wheel 5 at its rear end, is pivotally supported by the rear arm bracket 2c so as to be able to swing up and down.

Further, a fuel tank 7 and a seat 8 are arranged in order from the front on the upper side of the vehicle body frame 2, and the left, right and rear sides of the seat 8 are covered with side covers 93. Furthermore, the left, right and lower sides of the vehicle body frame 2 are surrounded by a cowling 9, within which the engine unit 1° is suspended and supported. This engine unit 10 is a water-cooled two-stroke V-type two-cylinder engine, and has a pair of upper and lower cylinder bodies 12. And the cylinder body 13 is roughly divided into upper and lower parts with respect to the horizontal plane,
They are connected so that the bank angle is 90 degrees, and are fastened to the crankcase 11 with head bolts 14.

An exhaust port 12a is formed in the rear wall of each cylinder body 12, and front ends of a pair of upper and lower exhaust pipes 15, 150 are connected to each exhaust port 12a. The upper exhaust pipe 15 is shown on the left above.

From the inside of the right main frame 2b, remove the side cover 9.
The lower exhaust pipe 15 extends substantially horizontally from the lower left side of the crankcase 11 to the right side of the vehicle to the rear end of the vehicle. .

Each piston 16 inserted into each cylinder of the cylinder body 12 is connected to a connecting rod on a left and right crank arm 17a of a crankshaft 17 disposed in the front part of the crankcase 11 in the vehicle width direction. Connected via IB. Each crank arm 17a is located in left and right crank chambers 11a integrally formed within the crankcase 11.

Further, an intake opening 11b is formed between the upper and lower cylinder bodies 12.12 when viewed from the side of the front wall of each crank chamber 11a, and an intake pipe portion 11c is formed in the intake opening 11b. It is integrally formed so as to extend substantially horizontally.

A discharge port 20b, which is a downstream opening of the carburetor 20, is connected to each intake pipe portion 11C via a carburetor joint 19 made of hard rubber. Therefore, each vaporizer 2
0, the axis of the venturi passage is substantially horizontal and is located at a height between the crankcase shaft 7 and the passageway, and the intake port 20a, which is the upstream opening, faces the front of the vehicle.

Further, an air cleaner 21 is disposed below the engine unit 10 and on the right side in the vehicle width direction. The air cleaner 21 has a cylindrical shape extending in the front-rear direction along the lower surface of the crankcase 11, and has a rear case 21a.
, the front case 21b is divided into two parts, and both cases 21
An element is interposed between a and 21b.

The rear end surface of the rear case 21a is located near the bottom of the left and right rear arm brackets 2c, and the lower end of an intake duct 27 for introducing outside air into the air cleaner 21 is connected to the rear end surface. There is. This intake duct 27
extends vertically upward between the left and right rear arm brackets 2c and 2c and on the right side of the shock absorber 30, and opens in the tank cover 7 after being bent forward.

Further, a cylindrical connecting duct 2 is provided on the front wall of the front case 21b.
2 are connected to each other, and the front part of the connecting duct 22 is bulged upwards of the vehicle to form a surge tank 25.

This surge tank 25 includes a rear half 25a and a front half 25a.
It is divided into two parts b, and is removably connected with a fastening bolt. The rear half 25a is large enough to accommodate the carburetor 20, and is shaped to fill the space formed by the upper and lower cylinder bodies 12, 12, and the rear wall of the rear half 25a is The connecting pipe portion 11C passes through it. Further, the front half portion 25b is curved backward in a concave shape to avoid interference with the front wheel 3.

Additionally, a radiator 24 is provided above the surge tank 25.
is installed. The radiator 24 has a core portion 24a.
The head tank part 24b is connected to the left and right ends of the main frame 2b, and the brackets 24c of the left and right head tank parts 24b are supported by support brackets fixed to the main frame 2b. .

Next, the effects of this embodiment will be explained.

In this embodiment, outside air is sucked into the air cleaner 21 through the intake duct 27, filtered by the element, and then passed through the connecting duct 22. It passes through the surge tank 25 and is sucked into the carburetor 20, where it becomes a mixture with gasoline and is sucked and supplied into the crank chamber 11a. Since the air cleaner 21 is disposed below the engine and connected to the carburetor 2o through the connecting duct 22 and the surge tank 25, clean air is supplied to the engine without any hindrance while adopting the front intake/rear exhaust system. can.

In this embodiment, the air cleaner 21 is placed in a relatively wide space below the engine and close to the carburetor 2°, so that a sufficient capacity of the air cleaner 21 can be secured, and the connection with the carburetor 20 can be For example, if the air cleaner is disposed inside the tank cover 7, sufficient air cleaner capacity can be secured, but the connecting duct becomes long.

Further, in this embodiment, the intake duct 27 is connected to the tank cover 7.
Since the tank cover 7 is extended to a high place inside the tank cover 7 and opened inside the tank cover 7, rainwater and the like can be prevented from entering into the air cleaner 21.

Furthermore, since this embodiment adopts a structure in which the entire vaporizer 20 is housed within the surge tank 25, there is no need to bulge the front wall of the surge tank 25 forward from the intake port 20a of the vaporizer 2o. , there is no need to extend the foil base.

In the above embodiment, the intake duct 27 may be arranged along the side of the vehicle, as shown in the vehicle. In this case, the intake duct 27 may be disposed on either the left side, the right side, or both.

〔Effect of the invention〕

As described above, according to the intake system for a motorcycle according to the present invention, it is possible to secure an air cleaner capacity in a relatively wide space below the engine and close to the fuel supply device, and also prevent the intrusion of rainwater, etc. It has a preventive effect.

[Brief explanation of drawings]

1 and 2 are diagrams for explaining a self-repairing two-wheeled vehicle according to an embodiment of the present invention. FIG. 1 is a left side view of the motorcycle in which the device of this embodiment is adopted, and FIG. FIG. 3 is a side view showing a modified example of the intake duct route, and FIG. 4 is a front view thereof. In the figure, 1 is a motorcycle, 10 is an engine, 15 is an exhaust pipe, 20 is a carburetor (fuel supply device), 21 is an air cleaner, and 27 is an intake duct. Patent Applicant Yamaha Motor Co., Ltd. Agent Patent Attorney Tsutomu Tsutomu Figure 2 Figure 4

Claims (1)

[Claims] (1) In a motorcycle having a fuel supply device connected to the front side of the engine and an exhaust pipe connected to the rear side, an intake device for supplying clean air to the engine, and an air cleaner arranged below the engine. An intake system for a motorcycle, characterized in that an intake duct is connected to the fuel supply system and leads outside air into the air cleaner above the engine.