JPH0367915B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the structure of an intake device that guides fresh air to an air cleaner in a motorcycle in which the front of the head pipe and both left and right sides of the front fork are covered with a cowling.

[Prior Art] Air cleaners for motorcycles are usually located near the engine and deep inside the vehicle body, so if the ventilation around the air cleaner deteriorates, the temperature of the intake air will increase. This adversely affects the filling efficiency of the intake air. Particularly in motorcycles with a cowling attached to the front end of the frame, the presence of the cowling tends to trap hot air from the engine around the air cleaner, which tends to raise the temperature of the air sucked into the air cleaner.

In order to eliminate such problems, conventionally an air intake duct was provided to introduce fresh air into the air cleaner, and the inlet end of this air intake duct was opened immediately after the head pipe located at the front end of the frame, thereby preventing air from entering from the front while driving. 2. Description of the Related Art Motorcycles that actively guide cool, fresh running air around an air cleaner are known.

[Problems to be Solved by the Invention] However, in this configuration, since the inlet end of the intake duct is close to the circumferential surface of the head pipe, the running wind flows through the narrow space between the head pipe and the inlet end of the intake duct. This causes the wind to flow into the intake duct, resulting in an extremely large inflow resistance of the wind.

As a result, the amount of air guided around the air cleaner is substantially reduced, and the temperature of the air sucked into the air cleaner cannot be lowered sufficiently.

The present invention was developed based on these circumstances, and it is possible to efficiently guide cold fresh air to the air cleaner and increase the filling efficiency of intake air.
Moreover, it is an object of the present invention to provide an intake device for a motorcycle that has a simple structure and a good appearance without the need to make holes for passing intake system components in an external component that covers an air cleaner. The purpose of the present invention is to provide an intake device for a motorcycle that has a simple structure and a good appearance.

[Means for Solving the Problems] Therefore, in the present invention, a pair of left and right main pipes extending rearward are connected to a head pipe that pivotally supports a front fork, and an engine is disposed below these main pipes. In a motorcycle in which the front of the upper part of the head pipe and the front fork is covered with a cowling, and the left and right sides of the cowling are extended rearward through the outside of the upper part of the front fork, the rear seat and the rear seat are placed on the main pipe from just behind the head pipe. In between, exterior parts are arranged so that the driver can fit them between his/her knees.
An air cleaner connected to the engine is placed inside this exterior part, and a pair of left and right intake system parts for guiding fresh air to the air cleaner is placed inside the left and right sides of the cowling. It is characterized in that the downstream end of the intake air is led to the air cleaner through the lower part of the main pipe.

[Function] According to this configuration, the intake system parts connected to the air cleaner are located outside the left and right sides of the head pipe and front fork in the cowling, so the flow of fresh air toward these intake system parts is directed to the head pipe and front fork. Unobstructed by forks. Therefore, the resistance to the inflow of fresh air is reduced, and a sufficient amount of fresh air can be efficiently guided to the air cleaner.

Moreover, since the downstream end of the intake system parts is connected to the air cleaner through the lower part of the main pipe, there is no need to cover the air cleaner and make holes etc. in external parts exposed to the outside for the intake system parts to pass through. The structure can be simplified. Therefore, there is no need to change the shape of external parts, and
This external part becomes smooth with few irregularities, and together with the fact that the above-mentioned intake system parts are housed inside the cowling, the first half parts from the cowling to the external part are neatly arranged, resulting in a good external appearance.

[Embodiment] An embodiment of the present invention will be described below based on FIGS. 1 to 4.

The frame designated by reference numeral 1 in FIG. 1 is provided with a head pipe 2 at its front end. A pair of left and right main pipes 3 extending rearward and obliquely downward, and a down tube 4 extending downward are joined to the head pipe 2. The lower end of the down tube 4 is extended rearward, and this extended end is joined to the rear end of the main pipe 3 via a bracket 5. A front end of a rear arm 6 is pivotally supported on the bracket 5 via a pivot shaft 7, and a rear wheel 8 is supported at the rear end of the rear arm 6.

Further, a front fork 9 is pivotally supported on the head pipe 2 via a steering shaft (not shown). The front fork 9 is formed by connecting the upper parts of left and right fork tubes 10a and 10b with an upper bracket 11 and an under bracket 12.
Both brackets 11 and 12 are connected to the steering shaft. And front fork 9
A front wheel 13 is supported at the lower end of the front fork 9, and the front fork 9 is steered by a bar handle 14 attached to an upper bracket 11.

The head pipe 2 is provided with a support stay 15 that extends forward.
Instruments 17 such as a headlamp 16 and a speedometer are attached to the vehicle.

Further, an engine 20 is mounted in the rear lower part of the head pipe 2, that is, in a space surrounded by a main pipe 3 and a down tube 4 connected to the head pipe 2. Engine 20 of this embodiment
is a water-cooled 4-cycle 4-cylinder engine, and four downdraft type carburetors 22 connected to each cylinder are arranged above the forward-inclined cylinder 21. An intake pipe 23 extending upward is connected to an intake upstream end of the carburetor 22, and these intake pipes 23 are connected to an air cleaner 24.
The air cleaner 24 is located immediately after the head pipe 2 and above the engine 20 sandwiched between the left and right main pipes 3, and the intake pipe 23 passes through its lower surface. Further, a cover 25 in the shape of a fuel tank is installed on the front half of the main pipe 3 so that the driver can put his/her knees between them. The cover 25 is exposed to the outside of the motorcycle and constitutes an external appearance part,
It covers an air cleaner 24 that protrudes upward from between the main pipes 3. The cover 25 is provided from just behind the head pipe 2 to between the rear seat 26 and the cover 25.
The rear part of the seat 26 is connected to the seat 26.

On the other hand, a synthetic resin cowling 30 is attached to the front end of the frame 1. The cowling 30 is attached to the head lamp 16 in front of the head pipe 2.
It consists of a main body part 31 that covers the periphery of the main body part 31 and the instruments 17, and left and right side panel parts 32 that extend rearward from both left and right sides of the main body part 31 to cover both upper sides of the head pipe 2 and front fork 9. The panel portion 32 covers the front end portions of the main pipe 3 and the down tube 4 from the side. In this cowling 30, the rear end of the side panel part 32 is fixed to the main pipe 3 and the down tube 4 via screws 34, and the lower front end of the main body part 31 is fixed to the head pipe 2.
It is fixed via screws 36 to a bracket 35 welded to the bracket 35 .

A space 37 is secured between the side panel portion 32 of the cowling 30 and the frame 1, as shown in FIG. In this space 37, a pair of left and right intake chambers 38 having a large capacity are arranged at positions outside the rotation range of the front fork 9.
The intake chamber 38 is supported by the inner surface of the side panel portion 32 via a support 43, and extends substantially horizontally in the front-rear direction on the outside of the front fork 9. A communication passage 40 extending toward the air cleaner 24 is connected to the inner surface of the intake chamber 38 . As shown in FIG. 4, the communication path 40 is led to the inside of the frame 1 through a space 45 sandwiched between the lower surface of the front end of the main pipe 3 and the rear surface of the upper end of the down tube 4. The tip of the side reaches below the air cleaner 24. and,
The leading ends of the communication passages 40 are joined together and connected to a communication port 41 that opens on the lower surface of the front end of the air cleaner 24, and an element 42 surrounding the opening of the communication port 41 is housed inside the air cleaner 24. ing.

An intake port 39 is opened at the front end of the intake chamber 38 . The intake ports 39 extend forward on both left and right sides of the front fork 9 and are located in the openings 33 of the cowling 30.

Therefore, in the case of this embodiment, the above-mentioned intake port 3
The intake chamber 38 and the communication passage 40 constitute intake system components that guide fresh air to the air cleaner 24. For this reason, during engine operation, fresh air sucked in from the intake port 39 of the intake chamber 38 expands within the intake chamber 38 and then enters the communication path 39.
0 to the air cleaner 24. The fresh air filtered while passing through the element 42 is expanded again in the air cleaner 24 and then distributed to each carburetor 22 through the intake pipe 23.

Note that the side panel portion 32 covering the intake chamber 38 is curved inward as it advances upward, and projects above the intake port 39, and the intake port 39 is covered from above by this projecting portion 32a. . Therefore, even when the vehicle is running or stopped, rainwater flows through the intake port 39 into the intake chamber 38.
It cannot be inhaled.

According to such a configuration, the left and right intake chambers 38 for guiding fresh air to the air cleaner 24 are located outside the left and right sides of the head pipe 2 and the front fork 9 inside the cowling 30, so that these intake chambers 38 The flow of fresh air sucked into the intake port 39 of the engine is not obstructed by the head pipe 2 or the front fork 9. Therefore, the resistance to the flow of fresh air into the intake port 39 is reduced, and a sufficient amount of fresh air can be efficiently guided to the air cleaner 24 via the communication path 40.

Therefore, the temperature of the intake air taken into the engine 20 can be kept low, which has the advantage of improving the filling efficiency of the intake air accordingly.

At the same time, the intake chamber 38 and the communication passage 40
Since it does not need to protrude greatly to the upper side of the cowling 30 or the front fork 9, it does not interfere with driving operation and good forward visibility can be ensured.

Moreover, since the communication passage 40 led out from the intake chamber 38 is led to the air cleaner 24 through the space 45 between the main pipe 3 and the down tube 4, the cover 24 that forms the shape of the fuel tank
There is no need to make a hole etc. for passing the communication path 40 through 5.
The shape of the cover 25 can be simplified. Therefore, there is no need to change the shape of the cover 25, and the cover 25 itself becomes smooth with few irregularities.

Therefore, the above-mentioned intake chamber 38 and communication passage 40 are housed inside the cowling 30, and the surroundings of the cowling 30 and cover 25 are neatly tied together, which provides advantages such as improving the appearance of the motorcycle. be.

In the above embodiment, a case has been described in which the intake chamber 38 is fixed to the cowling 30 via the support 43, but the present invention is not limited to this, and can be applied to other embodiments shown in FIGS. 5 and 6, for example. The intake chamber 38 may be fixed to the frame 1 side as shown in FIG. That is, in this case, the intake chamber 38 is fixed to the main pipe 3 and a reinforcing member 51 installed between the main pipe 3 and the down tube 4 using screws 50.

Further, in each of the above embodiments, an intake chamber is disposed between the cowling and the frame, but an intake resonator may be disposed in place of this intake chamber.

[Effects of the Invention] According to the present invention described in detail above, the flow of fresh air sucked into the intake system parts is not obstructed by the head pipe or front fork, so the flow of fresh air into the intake system parts is reduced. With less resistance, a sufficient amount of fresh air can be efficiently guided to the air cleaner. Therefore, the temperature of the intake air taken into the engine can be suppressed to a low level, and the filling efficiency of the intake air is improved accordingly.

Furthermore, there is no need to make holes for passing air intake system parts through exterior parts that are exposed to the outside, so there is no need to change the shape of the exterior parts, and the exterior parts themselves can be smooth with fewer irregularities. . Therefore, the surroundings of the cowling and external parts are neatly tied together, which has the advantage of improving the external appearance.

[Brief explanation of drawings]

1 to 4 show an embodiment of the present invention, in which FIG. 1 is a side view of a motorcycle, FIG. 2 is a plan view of the front half of the motorcycle, and FIG. 3 is a sectional view of an air cleaner portion. FIG. 4 is a view taken along the line - in FIG. 3, FIGS. 5 and 6 show other embodiments of the present invention, FIG. 5 is a view corresponding to FIG. 4, and FIG. FIG. 5 is a sectional view taken along the line - in FIG. 5; 1... Frame, 2... Head pipe, 9...
Front fork, 20... Engine, 24...
Air cleaner, 25... Exterior parts (cover), 3
0... Cowling, 33... Opening, 38, 40
...Intake system parts (intake chamber, communication path), 39
...Intake port, 45...Space.

Claims (1)

[Scope of Claims] 1 A pair of left and right main pipes extending rearward are connected to a head pipe that pivotally supports the front fork, an engine is disposed below these main pipes, and a cowling is provided at the upper front of the head pipe and front fork. In a motorcycle in which the left and right sides of this cowling are extended rearward through the outside of the upper part of the front fork, the rider can ride the cowling on the main pipe from just behind the head pipe to between the seat and the rear seat. An exterior part shaped so that it can be held between both knees is placed, and an air cleaner connected to the engine is placed inside this exterior part, and fresh air is guided to the air cleaner inside the left and right sides of the cowling. An intake system for a motorcycle, characterized in that a pair of left and right intake system parts are arranged, and the downstream ends of these intake system parts are led to the air cleaner through the lower part of the main pipe.