JPH0440234B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the arrangement of an air cleaner device in a two-wheeled motor vehicle.

Motorcycles are equipped with a main pipe extending rearward from the head pipe, an engine is placed below the main pipe, and a fuel tank is installed above the main pipe so as to straddle the fuel tank. There is.

In this type of motorcycle, the air cleaner device is installed between the fuel tank and the engine or between the engine and the rear wheel in order to shorten the distance to the engine intake port and reduce flow resistance in the intake passage. is placed between.

By the way, since these spaces are also spaces in which many other components are installed, it is difficult to secure a space for arranging an air cleaner device having a relatively large capacity here.

For example, when viewed from the side of a vehicle, a so-called front-rear V-type engine has a cylinder that is tilted forward (front cylinder) and a cylinder that is tilted backward (rear cylinder) that protrudes from the crankcase to form a substantially V-shape. In the case of a two-wheeled motor vehicle equipped with this, a carburetor is disposed in the V-shaped inner space sandwiched between the front cylinder and the rear cylinder, and the air-fuel mixture is supplied from there to both cylinders. Therefore, in motorcycles equipped with this type of front and rear V-type engines, in order to locate the air cleaner above the carburetor, the bottom plate of the fuel tank is recessed upward to create a space sufficient for locating the air cleaner. This means a reduction in fuel tank capacity.

This invention was made in view of these circumstances, and its purpose is to place the air cleaner in a position that does not significantly increase the flow resistance in the intake passage and has little effect on other components. This is an attempt to alleviate the crowded condition of the space between the engine, fuel tank, and rear wheels, where many components have conventionally been arranged densely.

The purpose of this is to extend the main pipe rearward from the head pipe, install the fuel tank across this main pipe, and place a V
A V-type engine is arranged with cylinders located in the front and rear with the space facing upward, and a plurality of intake ducts of this engine are arranged in the V-space and communicate with the main pipe, and the main In a motorcycle in which an air cleaner device is installed in a pipe, a downstream side of the air cleaner device is communicated with the inside of the main pipe, and the air that has passed through the air cleaner device flows into the intake duct via the inside of the main pipe, An extra space is provided between the lower end of the fuel tank and the head pipe, and the air cleaner device is arranged in this extra space, and the plurality of openings of the intake duct in the main pipe are arranged in the front-rear direction of the vehicle body. This can be achieved by doing.

Next, automatic 2 equipped with front and rear V-type engines shown in the figure
An example of a wheeled vehicle will be described. Reference numeral 1 denotes a head pipe, which serves as a steering fulcrum for the front wheels via a steering shaft and a front fork (not shown) inserted through the head pipe.

A main pipe 2 is made of a welded steel plate structure, the front end of which is welded to the steering pipe 1, and the inside thereof is a substantially sealed space.
A bracket 3 is attached to the rear end of the main pipe 2 and forms part of the frame. Reference numeral 4 denotes an engine, which in this embodiment is of a V-type front and rear. The rear part of the engine 4 is attached to the main pipe 2 via the bracket 3 mentioned above, and the front part thereof is attached to the main pipe 2 via the bracket 41. This engine 4
Capretors 5a and 5b (only 5b is shown) are arranged in the V space between the front cylinder 4a and the rear cylinder 4b. Exhaust pipes 6a and 6b are connected to the front and rear cylinders 4a and 4b, respectively. A fuel tank 7 is provided so as to straddle the main pipe 2 above the engine 4. Note that 71 indicates the bottom plate of the fuel tank. Air cleaner devices 8, 8 are attached to the side surface of the main pipe 2 between the fuel tank 7 and the head pipe 1. This position is the free space 73 where the front end of the fuel tank was conventionally located, but since the front end of the fuel tank was flat and the lower part was raised forward, the air cleaner device was placed at this location. The reduction in tank capacity is very small. 9 is a seat, and 10 is a rear wheel.

The air cleaner device 8 includes a case body 81, a lid 82, and an element 83. The case body 81 has a container shape with side openings, and an air intake port 84 is provided on the peripheral wall of the case body 81 on the rear side of the vehicle, and a communication port 85 is provided on the side surface of the main pipe 2. The lid 82 is made of plastic material together with the case body 81, and the lower edge of the lid 82 on the front side of the vehicle extends downward from the outer shape of the case body 81 and is bent to direct wind from the vehicle running between the engine 4 and the fuel tank. A guide plate 82a is integrally formed between the two. The element 83 is a dry element and is mounted by interposing a rubber O-ring between the case body 81 and the lid 82 and closing the lid 82 by sandwiching them together.

Next, the flow of intake air in this embodiment will be explained in order. The traveling wind guided by the wind guide plate 82a reaches the space below the fuel tank bottom plate 71. Here, the air enters the air cleaner device 8 through the air intake port 84. Since the air intake port 84 opens toward the rear of the vehicle, only the running wind without water droplets enters the air cleaner device even if the running wind contains water droplets. The air that has reached the case body 81 is cleared of dust as it passes through the element 83 and enters the main pipe 2 through the communication port 85. The inside of the main pipe 2 is box-shaped and has an extremely large capacity compared to the intake flow rate.
Therefore, the room formed within this main pipe 2 has the function of an air chamber. Therefore, the air sucked by the negative pressure of the engines 4a, 4b is sucked from this chamber, so the flow path resistance is not large. The air sucked in from here through the intake ducts 51a, 51b passes through the carburetors 5a, 5b, becomes an air-fuel mixture, is burned in each cylinder, and is discharged into the atmosphere from the respective exhaust pipes 6a, 6b.

In the embodiments described above, the engines are front and rear V-type, but the present invention is not limited to this type of engine. Further, in this embodiment, air cleaner devices are provided on both sides of the main pipe, but the air cleaner device may be provided on only one side.

As explained above, since the two-wheeled motor vehicle according to the present invention is configured as above, that is, the extra space utilizes the shape of the lower end of the fuel tank which is raised forward. Therefore, the reduction in fuel tank capacity due to the creation of this extra space is slight.

In addition, since the openings of the plurality of intake ducts in the main pipe are arranged in the longitudinal direction of the vehicle body, the width (left and right width) of the main pipe can be made narrower, and as a result, the recessed part of the fuel tank that straddles the main pipe can be made narrower. The groove width can be made narrower.

Considering the above-mentioned effects, in the motorcycle according to the present invention, even though an extra space is provided between the fuel tank and the head pipe, the capacity of the fuel tank is not reduced, and other This reduces the density of the space surrounded by the engine, fuel tank, and rear wheels, where many components were traditionally arranged densely, and reduces flow resistance in the intake passage. Something that can be kept small.

[Brief explanation of drawings]

The drawings relate to an embodiment of the present invention, and FIG. 1 is a partially sectional schematic side view, and FIG. 2 is a partially sectional plan view. 1...Head pipe, 2...Main pipe, 4
...Engine, 51a, 51b...Intake duct,
7... Fuel tank, 73... Surplus space, 8... Air cleaner device.

Claims (1)

[Claims] 1. A main pipe is extended rearward from the head pipe, and a fuel tank is installed on this main pipe so as to straddle it, and the cylinders are positioned forward and backward with a V space facing upwards below the fuel tank. A V-type engine is arranged, and a plurality of intake ducts of this engine are arranged in the V space and communicated with the main pipe, and an air cleaner device is installed in the main pipe, and the air cleaner device In a motorcycle in which a downstream side is communicated with the inside of the main pipe, and the air that has passed through the air cleaner device flows into the intake duct through the inside of the main pipe, between the lower end of the fuel tank and the head pipe. A two-wheeled motor vehicle, wherein an extra space is provided in the extra space, and the air cleaner device is disposed in the extra space, and a plurality of openings of the intake duct in the main pipe are arranged in the longitudinal direction of the vehicle body.